dimensioning wcdma ran

Dimensioning WCDMA RAN

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# Nokia Siemens Networks 1 (113)

RNC3267_trialNokia WCDMA RAN, Rel. RAS06, SystemLibrary, v. 1

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2 (113) # Nokia Siemens Networks DN70118376Issue 2-0 en18/06/2007


Contents

Contents 3

Summary of changes 5

1 Introduction to dimensioning WCDMA RAN 7

2 Dimensioning Air interface 11

3 R99 DCH dimensioning 153.1 Intoduction to R99 DCH dimensioning 153.2 R99 DCH coverage dimensioning 173.2.1 Uplink link budget 173.2.2 Downlink link budget 223.2.3 Cell range and coverage 263.3 R99 DCH capacity dimensioning 283.3.1 Load calculation based on traffic inputs 283.3.2 DL power calculation vs. load 30

4 HSDPA dimensioning 334.1 Introduction to HSDPA dimensioning 334.1.1 HSDPA features in RAS06 354.1.2 Supporting R99 formulas 364.2 HSDPA coverage dimensioning 364.2.1 Uplink link budget 364.2.2 Downlink link budget 374.2.3 Cell range and coverage 414.3 HSDPA capacity dimensioning 42

5 HSUPA dimensioning 455.1 Introduction to HSUPA dimensioning 455.1.1 HSUPA features in RAS06 475.1.2 Supporting R99 formulas 485.2 HSUPA coverage dimensioning 485.2.1 Uplink link budget 485.2.2 Downlink link budget 525.2.3 Cell range and coverage 525.3 HSUPA capacity dimensioning 53

6 Dimensioning transport network 57

7 Dimensioning BTS 617.1 Dimensioning Flexi WCDMA BTS 617.1.1 Capacity 627.1.2 Baseband capacity and HSDPA 637.1.3 Capacity licenses 647.1.4 Flexi WCDMA BTS and transmission 657.2 Dimensioning UltraSite WCDMA BTS 657.2.1 WSPA/C processing capacity 67

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Contents

7.2.2 UltraSite WCDMA BTS baseband capacity and HSDPA 687.2.3 Dimensioning steps 697.2.4 HSPA sharing 717.3 HSDPA and BTS dimensioning 727.3.1 Tcell grouping 747.4 HSUPA and BTS dimensioning 757.5 Extended Cell 777.6 BTS counters 787.7 WCDMA BTS capacity allocation principles 797.7.1 UltraSite WCDMA BTS 797.7.1.1 Primary/Secondary WAM 807.7.1.2 Master/Slave WAM 807.7.1.3 WSP and WAM allocation within a subrack 817.7.1.4 Common Control Channel (CCCH) allocation 827.7.1.5 Dedicated Channel (DCH) allocation 847.7.1.6 Recovery actions 887.7.1.7 HSDPA 897.7.2 Flexi WCDMA BTS 94

8 Dimensioning RNC 95

9 Dimensioning interfaces 979.1 Dimensioning Iub interface 979.1.1 Transport Bearer Tuning 979.1.2 Hybrid transport 989.1.3 Iub VCC configuration 989.1.4 Protocol overheads 1019.1.5 Connection Admission Control 1029.1.6 Iub signalling links 1029.1.7 Examples of Iub configurations 1049.1.8 Interface capacity 1059.1.9 BTS internal link configurations 1069.2 HSDPA and Iub dimensioning 1069.3 Dimensioning Iur interface 1079.4 Dimensioning Iu-CS interface 1099.5 Dimensioning Iu-PS interface 1119.6 Dimensioning Iu-BC interface 1129.7 Iu and Iur MTP3 links 112



Summary of changes

Changes between document issues are cumulative. Therefore, the latestdocument issue contains all changes made to previous issues.

Changes between issues 1-3 and 2-0

Dimensioning Air interface:

This section has been updated with information on R99 DCHdimensioning, HSDPA dimensioning and HSUPA dimensioning.

R99 DCH dimensioning:

This is a new section.

HSDPA dimensioning:


HSUPA dimensioning.


Dimensioning BTS:

Sections Dimensioning Flexi WCDMA BTS, Dimensioning UltraSiteWCDMA BTS and HSDPA and BTS dimensioning have been updated.New sections HSUPA and BTS dimensioning, Extended Cell and BTScounters have been added.

Dimensioning RNC:

RNC-related dimensioning information has been updated to RAS06 level.

Dimensioning interfaces:

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Summary of changes

Sections Dimensioning Iub interface and Iu and Iur MTP3 links have beenupdated.


Table 1. Modified chapters in Dimensioning WCDMA RAN in issue 1-3

Changed chapter Impact See

Dimensioning BTS The number of cells handled byone WSPC has been corrected.

Dimensioning UltraSite BTS

Dimensioning interfaces The steps of Iu-PS dimensioninghave been simplified.

Dimensioning Iu-PS interface

RAN features anddimensioning

A reference has been corrected. RAN features and dimensioning


Table 2. Modified chapters in Dimensioning WCDMA RAN in issue 1-2

Changed chapter Impact See

Dimensioning BTS Information on the basebandExtension Module has beenadded. Carrier configurations havebeen updated.

Flexi BTS

Dimensioning BTS The number of cells and users forFlexi BTS have been updated.

HSDPA and BTS dimensioning

Dimensioning interfaces Information on the maximum sizeof AAL2 Path has been added.

Dimensioning Iub interface



1 Introduction to dimensioning WCDMARAN

Purpose

Dimensioning is the initial phase of network planning. Duringdimensioning, the first configuration estimates and requirements forcoverage, capacity and quality of service are planned. The approximatenumber of necessary base station sites and base stations, the averagevalues for the power budget, cell size, capacity, and initial networkconfiguration are estimated at this phase. The capacity requirements andthe overall quality of service targets determine the selection of the RANtransport network and the transport interfaces of base stations and RNCGSM operators can use dimensioning to estimate the service capability ofthe existing network in case of site reuse.

Note that in the dimensioning phase, only average values for the networkcan be calculated. More exact values for individual sites are calculated inthe actual planning phase.

The dimensioning instructions given in this document apply to RAS06system release, consisting of Nokia WCDMA BTS release WBTS4.0 andNokia WCDMA RNC release RN3.0.

Before you start

Check:

. Traffic expectations. An accurate traffic forecast is important innetwork dimensioning. Deviations must be taken into account incapacity planning.

. Population density in the area. Specify areas of population thatshould be covered in each phase of roll-out.

. Location probability. Specify system area availability indoors/outdoors.

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Introduction to dimensioning WCDMA RAN

. Regulations, for example, spectrum allocations (FDD/TDD andlicenced/unlicenced) and transmit power limitations.

. Specific system performance parameters.

The basic parameters for dimensioning are the following:

. quality of service in terms of call blocking and coverage probabilityper service

. estimated traffic requirements for voice users

. estimated traffic requirements for real-time and packet data users

. development of service requirements, the service profile as afunction of time

. radio network area information: the total area, division into differentsub-areas or area types, and the user distribution for each sub-area

Summary

Radio network dimensioning activities include coverage, capacity, andquality of service analysis. The results of this analysis are the main inputfor the dimensioning of the transport network.

Steps

1. Estimate coverage.

a. The coverage efficiency of WCDMA is defined by the averagecoverage area per site, for a predefined propagationenvironment, and supported traffic density.

b. Check the size of the area.

c. Take the area type into account and consider the suitability ofthe propagation model.

d. Different area types are, for example, dense urban, urban,suburban, and rural. There can also be special areas within anarea, for example an airport or an industrial area.

2. Estimate capacity.

a. Check the frequency range and the amount of spectrum thatcan be used.

b. Estimate the amount of supported traffic per base station site.

3. Estimate quality of service.



Consider blocking and location probability. Typical values are 2%and 95% respectively. Location probability varies for differentservices according to the required data rates. For example, thelocation probability for a service that requires faster data rates maybe smaller.

Expected outcome

A rough estimate of the required sites and network elements:

. base stations

. base station configurations

. RNCs

and requirements and strategy for:

. coverage

. quality

. capacity

. transport network

per service based on the given input parameters.

Further information

For further information, see Dimensioning transport network. See also:

. Dimensioning Air interface

. Introduction to RNC overload control in Overload Control in RNC

. Overview of Nokia WCDMA RAN configurations in ConfiguringWCDMA RAN

. Introduction to Nokia RAN configurations in Configuring WCDMARAN

For instructions, see Planning radio network in Planning WCDMA RANand Optimising and expanding WCDMA RAN in Optimising WCDMA RAN.

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Introduction to dimensioning WCDMA RAN

2 Dimensioning Air interface

The air interface dimensioning is based on the predicted subscriberdensity (subscribers/km2), subscriber traffic profiles, propagationenvironment, and Quality of Service (QoS) targets. With Wideband CodeDivision Multiple Access (WCDMA), the dimensioning has to be doneiteratively, considering the air interface load and cell range coupling. Theiteration steps are presented in Figure BTS dimensioning flow. Thecalculations are based on the basic WCDMA formulas, propagationmodels, and statistical analysis. In practice, the dimensioning is done withnetwork dimensioning or planning tools (such as NetDim or NetActPlanner, see NetAct Planner documentation).

Figure 1. BTS dimensioning flow

CapacityRequirement

Link BudgetCalculation

Area typesAntenna gains

Subscribers/kmTraffic/Subscribe

2

Load FactorCalculation

EquipmentRequirement

Cell RangeCalculation

Coverage targetsFading margins

Allowed blocking/queuing

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Dimensioning Air interface

For more information on dimensioning Air interface, see Introduction toR99 DCH dimensioning, Introduction to HSDPA dimensioning andIntroduction to HSUPA dimensioning.

See also Introduction to Nokia RAN configurations in Configuring WCDMARAN.

Air interface dimensioning in RAS06 increases in complexity with theintroduction of HSUPA. HSUPA causes some changes into thedimensioning methodology, as RF resources have to be shared with R99users (using DCH bearers). As both HSDPA and HSUPA (HSUPA worksonly with HSDPA) are optional features, dimensioning can be separated inthree main cases:

. Only R99 dimensioning

. Combined R99 + HSDPA dimensioning

. Combined R99 + HSPA (HSDPA + HSUPA) dimensioning

Also, additionally dedicated carriers for R99, R99 UL+HSDPA and HSUPA+HSDPA are possible.

This section on Air interface dimensioning concentrates on Combined R99+ HSPA (HSDPA + HSUPA) dimensioning, as it can be seen as the mostcomplex. This is due to the fact that R99 DCH traffic influences all otherfeatures, HSDPA and HSUPA.



Figure 2. Air interface dimensioning process for shared DCH + HSPA carrier

Tip

Channel Element (CE) is a capacity unit of BTS baseband processing.

One CE is required in UL and DL for AMR 4.75 - 12.2 kbps and WB-AMR 6.6 - 12.65 kbps. For MultiRAB calls, CE consumption iscalculated by adding together the individual RAB CE needs.

Table 3. CE consumption examples

CE for single RAB

Uplink Downlink

AMR 4.75-12.2 kbps, WB-AMR 6.6-12.65 kbps

1 1

PS 64 / 384 kbps 4 16

PS 128 / 384 kbps 4 16

PS 384 / 384 kbps 16 16

Air interface dimensioning,shared carrier DCH + HSPA

Coverage dimensioningselection:

- Link Budget R99(based on service)- Link Budget HSDPA(based on cell edgethroughput)- Link Budget HSUPA(based on cell edgethroughput)- Output # of coverage sites

R99 capacitydimensioning

Resultevaluation

CECalculation

HSDPA capacitydimensioning

HSUPA capacitydimensioning

Iu-bDimensioning

RNCDimensioning

Additionalcapacity Node Bs

Dimensioning inputs and requirements

Coverage dimensioning Capacity dimensioning

Input: availableHSUPA capacity

Output: HSUPAthroughput

OK

Not OK

UL/DL Load,Node B DL power

Output: HSDPAthroughput

Input: availableHSDPA capacity

# ofNode Bs

(coverage +capacity)

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Dimensioning Air interface

DCH traffic load has to be taken into account in capacity dimensioning ofHSDPA in downlink and HSUPA in uplink. This sets some challenges onestimating the capacity available for different services, especially HSPAservices. Overall, dimensioning can be based on different starting points,such as having the coverage dimensioning for HSUPA 64 kbps or forHSDPA cell edge throughput of 128 kbps. Similarly, capacity dimensioningcan be based on DCH load estimation or HSUPA/HSDPA cell averagethroughput.

Additionally, as there are more WCDMA frequencies available, theoperating frequency can have a high influence on the dimensioningparameters. It affects, for example:

. Node B noise figure (for example, Flexi ~2 GHz ≈ 2 dB, ~900 MHz ≈2.8 dB)

. Node B antenna gain (for example,. ~2 GHz =17.5 dBi, ~900MHz =14.5 dBi)

. Cable loss (for example, ~2 GHz = 5.9 dB/100 m, ~900MHz = 3.7dB/100 m)

. User equipment noise figure (for example,~2 GHz ≈ 8 dB, ~900 MHz≈ 11 dB)

. Propagation. Lower frequency has better propagation performance.Therefore, carrier frequency has a big influence on cell rangecalculations.

For more detailed information on the dimensioning of R99 DCH, HSDPAand HSUPA, see Introduction to R99 DCH dimensioning, Introduction toHSDPA dimensioning and Introduction to HSUPA dimensioning.

For more information on HSDPA and HSUPA, see High-speed packetaccess (HSPA) in HSPA Overview .



3 R99 DCH dimensioning

3.1 Intoduction to R99 DCH dimensioning

R99 dedicated traffic channel (DCH) dimensioning has to be noted also inHSPA dimensioning. In case of shared DCH + HSPA, the R99 DCH trafficaffects both HSDPA and HSUPA capacity as well as coverage.

The general R99 dimensioning process is shown in Figure R99dimensioning flow.

Figure 3. R99 dimensioning flow

The figure shows the basic parts of the dimensioning flow, including inputs:

Air interface dimensioning,only DCH carrier


- Link Budget R99(based on service)- Output # of coverage sites

R99 capacitydimensioning

Resultevaluation

CECalculation

Iu-bDimensioning

RNCDimensioning




OK

Not OK

# ofNode Bs

(coverage +capacity)

Input:available capacity

Output:R99 UL/DL load

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R99 DCH dimensioning

. Area type distribution, area parameters

. Subscriber density (subscribers / km2) per area type

. Busy hour (BH) traffic/subscriber by traffic types (for example, voice,CS data 64 kbps, PS data 64 kbps)

. Service targets

. Node B type, operational parameters (frequency, power,orthogonality)

The steps for air interface dimensioning are:

1. Coverage dimensioning

. Calculate or estimate uplink/downlink load factor.

. Calculate uplink/downlink radio link budget.

. Calculate cell range and Node B coverage area for the selectedcoverage limiting service.

For more information, see R99 DCH coverage dimensioning.

2. Capacity dimensioning

. Estimate and calculate the traffic and capacity demand based ontraffic and subscriber profile inputs.

. Compare the capacity need with the number of coverage sitesoffered capacity.

. If R99 capacity is not enough, you can add new Node Bs forcapacity, tune the parameters in link budget or capacity-relatedfeature parameters, and add dedicated carriers.

For more information, see R99 DCH capacity dimensioning.

Expected outcome

. Cell ranges

. Number of BTSs/area

. BTS configurations

. Subscribers/BTS, traffic/BTS



3.2 R99 DCH coverage dimensioning

R99 DCH coverage dimensioning includes uplink link budget, downlinklink budget, and cell range and coverage.

3.2.1 Uplink link budget

The uplink link budget can be used to define CS and PS service maximumpath loss. Table Example of R99 UL DCH link budget shows the basic linkbudget for R99 UL DCH.

Table 4. Example of R99 UL DCH link budget

Service Speech CD Data PS Data

Service Rate (kbps) 12.2 64 64

Transmitter - Handset

Max Tx Power (dBm) 24 24 24

Tx Antenna Gain (dBi) 0 0 0

Body Loss (dB) 3 0 0

EIRP (dBm) 21 24 24

Receiver Node B

Node B Noise Figure(dB)

2

Thermal Noise (dBm) -108

Uplink Load (%) 50

Interference Margin (dB) 3-0

Interference Floor -103.0

Service Eb/No (dB) 4.4 2 2

Service PG (dB) 25.0 17.8 17.8

Receiver Sensitivity (dB) -123.6 -118.8 -118.8

Rx Antenna Gain (dBi) 18.0 18.0 18.0

Cable Loss (dB) 0.5 0.5 0.5

Benefit of using MHA(dB)

0 0 0

UL Fast Fade Margin(dB)

1.8 1.8 1.8

UL Soft Handover Gain(dB)

1.5 1.5 1.5

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Table 4. Example of R99 UL DCH link budget (cont.)

Service Speech CD Data PS Data

Gain against shadowing(dB)

2.5 2.5 2.5

Building PenetrationLoss (dB)

12 12 12

Indoor Location Prob.(%)

90 90 90

Indoor Standard Dev.(dB)

10 10 10

Shadowing margin (dB) 7.8 7.8 7.8

Isotropic PowerRequired (dB)

-123.5 -118.7 -118.7

Allowed Prop. Loss(dB) 144.5 142.7 142.7

UL PS services can have also other bit rates, for example 128 and 384kbps. Usually the coverage dimensioning is still made with 64 kbps CS orPS.

Defining uplink link budget

1. Define the service parameters.. Service bit rate

The bit rate depends on service, which can vary in speechservice bit rates (for example, 4.75, 5.9, 7.95, 12.2 kbps) topacket service bit rates (for example, 64, 128 and 384 kbps) aswell as video service (for example, 64 kbps).

. Service Processing Gain

High processing gains correspond to services with low bitrates. These services tend to have more relaxed link budgetsand generate smaller increments in cell loading.

. Service Eb/No. Eb/No value varies between services and alsobetween selected propagation channels. The following tableshows the recommended Eb/No values for commonly usedservices in dimensioning.

Service Processing Gain = 10 * LOGChip Rate

Bit Rate



Table 5. Eb/No values for network dimensioning

Eb/No [dB] Speech 64 kbps 128 kbps 384 kbps

Uplink

3 km/h, macrocell

4.4 2 1.4 1.7

120 km/h, macrocell

5.4 2.9 2.4 2.9

Downlink

3 km/h, macrocell

7.9 5 4.7 4.8

120 km/h, macrocell

7.4 4.5 4.2 4.3

Eb/Nos for lower and wideband AMR codecs and for lower PSdata services can be derived from the values (3 km/h) shownabove. See Table Eb/No values for lower and wideband AMRcodecs and lower PS data services.

Table 6. Eb/No values for lower and wideband AMR codecs and lower PSdata services

Narrowband AMR Wideband AMR Lower PS

Bit rate(kbps)

4.75 5.9 7.95 6.65 8.85 12.65 8 16 32

Uplink Eb/No [dB]

6.4 5.8 5.2 5.5 5.0 4.3 3.9 2.5 2.2

DownlinkEb/No [dB]

9.4 9.0 8.5 8.8 8.3 7.9 5.4 5.4 5.7

2. Define parameters for the UE.. UE max power and antenna gain

UE transmit power is dependent on the mobile type andusually varies between 21 and 24 dBm. Similarly, the antennagain varies from 0 dBi mobile terminals to 2 dBi data cards.

. Body loss

Body loss depends on service. Commonly during the calls themobile is located near the ear, and 3 dB body loss is noticed.

. EIRP

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EIRP represents the effective isotropic radiated power fromthe transmit antenna. In uplink it is computed from thefollowing equation:

Uplink EORP = UE Transmit Power + Transmit Antenna Gain -Body Loss

3. Define Node B parameters.. Node B noise figure

NF varies according to frequency and Node B performance.For example, for Flexi WCDMA BTS NF varies from 2 to 2.8dB according to the frequency.

. Antenna gain

Antenna gain varies from sectorised to omni antennas. Theantenna gain can be seen from antenna data sheet.

. Cable loss and Mast Head Amplifier

Cable loss can be assumed to be from 0.5 to 3 dB; in case ofFlexi WCDMA BTS the cable loss can be as low as 0.5 dB.When using MHA, the cable loss is compensated and thebenefit from MHA is the same as the assumed cable loss.

4. Calculate thermal noise according to the following formula:

ThermalNoiseDensity= k x T x B = -108 dBm

where:. k = Boltzmann’s constant, 1.43 E-23 Ws/K. T = Receiver temperature, 293 K. B = Bandwidth, 3 840 000 Hz

5. Calculate or estimate uplink load factor.

Calculate uplink load factor by WCDMA uplink load equation:

ηul Uplink load factor. Generally uplink load of 0.5– 0.7 is used in dimensioning.

N Number of users

Vj L1 activity factor of user j (0.67 for voice UL,0.63 for voice DL, 1.0 for data)

Eb/Noj Received energy per bit-to-noise density ratio(Eb/No) of user j

W WCDMA chip rate; 3.84 Mcps/s

=UL

Eb / Noj

W / Rj

v jj=1

j=N

* (1+ a * i)



Rj Data rate of user j

A Power rise of user j due to power control,depending on UE speed

i Ratio of other to own cell interference. Inuplink, the value depends on the BTSsectorisation:

Micro cell : Omni: 25% - 55%

Macro cell: Omni: 55%, 2-sector: 55%, 3-sector: 65%, 4-sector: 75%, 6-sector: 85%

It is recommended to use the maximum uplink load of 0.5–0.7, evenif in the initial phase of the network the subscriber traffic would notgenerate as much load. This is to avoid a situation where slightincreases in the traffic amounts may cause shrinkage of thecoverage areas. In rural areas, where major traffic is not expected, alower uplink load value may be used.

Calculate interference margin. This is calculated from the load factor.

6. Calculate Interference Floor.

Interference Floor is calculated from the load factor.

Interference_floor = Thermal noise + Node B noise figure +intereference_margin

7. Define receiver thermal sensitivity.

The receiver thermal sensitivity is computed according to theequation:

Receiver Sensitivity = Interference_floor + Required Eb/No -Processing Gain

This represents the receiver sensitivity when the system is loaded,that is, an interference margin has been included.

8. Define additional parameters.. UL fast fade margin, that is, power control headroom. The

recommended value for slow moving mobiles is 1.8 dB. Forfast moving mobiles it is 0 dB.

. Gain against shadowing. The recommended value is 2.5 dB.

. UL soft handover gain. The recommended value is 1.5 dB.

Interference_margin= -10 * LOG 1- TARGET_LOAD

100

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9. Define clutter-related parameters.

As shown in the example link budget, the maximum allowedpropagation loss calculation includes also a definition of indoorlosses and margins. Additionally, coverage can also be calculatedfor in-car and outdoor, but most commonly coverage should becalculated for indoors.. Slow fading margin, outdoor: 6 – 8 dB (lower for suburban and

rural). Slow fading margin, indoor: 10 – 15 dB (lower for suburban

and rural)

10. Define the required Isotropic power.

The required signal power is calculated to take into account thebuilding penetration loss and indoor standard deviation, as well asreceiver sensitivity and additional margins.

Isotropic power required = Receiver sensitivity - RxAntennaGain +cable loss - MHA gain + UL fast fade margin – Gain againstshadowing – UL SHO gain + BPL + shadowing margin

11. Define allowed propagation loss.

Allowedprop loss = EIRP - Isotropic power required

3.2.2 Downlink link budget

The downlink link budget can be used for defining CS and PS servicemaximum path loss. Table Example of R99 DL DCH link budget shows thebasic link budget for R99 DL DCH.

Table 7. Example of R99 DL DCH link budget

Service Speech CD Data PS Data PS Data PS Data

Service Rate (kbps) 12.2 64 64 128 384

Transmitter - Node B

Max Tx Power Total(dBm)

43

Max Tx Power (perRadiolink) (dBm)

34.2 37.2 37.2 38.0 38.0

Cable Loss (dB) 0.5 0.5 0.5 0.5 0.5

MHA Insertion Loss 0 0 0 0 0

Tx Antenna Gain (dBi) 18 18 18 18 18



Table 7. Example of R99 DL DCH link budget (cont.)

Service Speech CD Data PS Data PS Data PS Data

EIRP (dBm) 51.7 54.7 54.7 55.5 55.5

Receiver Handset

Handset Noise Figure(dB)

7


Downlink Load (%) 80

Interference Margin (dB) 7.0

Interference Floor (dBm) -94.0

Service Eb/No (dB) 7.9 5 5 4.7 4.8

Service PG (dB) 25.0 17.8 17.8 14.8 10.0

Receiver Sensitivity(dBm)

-111.1 -106.8 -106.8 -104.1 -99.2

Rx Antenna Gain (dBi) 0 0 0 0 0

Body Loss (dB) 3 0 0 0 0

DL Fast Fade Margin(dB)

0 0 0 0 0

DL Soft Handover Gain(dB)

2.5 2.5 2.5 2.5 2.5

Gain against shadowing 2.5 2.5 2.5 2.5 2.5

Building PenetrationLoss (dB)

12 12 12 12 12

Indoor Location Prob.(%)

90 90 90 90 90

Indoor Standard Dev.(dB)

10 10 10 10 10

Shadowing margin (dB) 7.8 7.8 7.8 7.8 7.8

Isotropic PowerRequired (dB)

-93.3 -92.0 -92.0 -89.3 -84.4

Allowed Prop. Loss (dB) 145.0 146.7 146.7 144.8 139.9

Commonly the service coverage is made based on the UL link budget, butit is good to verify the coverage also for downlink service.

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Defining downlink link budget

The parameter definition for downlink link budget is mostly the same as forR99 uplink DCH link budget, but with the some differences as describedhere.

1. Define service parameters.

Use downlink Eb/No values in Table Eb/No values for networkdimensioning in Defining uplink link budget.

2. Define UE parameters

You need to define RX Antenna Gain and Body Loss.

Define Handset Noise Figure (no Node B Noise Figure defined).

3. Define Node B parameters.

Node B parameters are the same as for UL, except that Node BNoise Figure is not defined.. Max Tx Power per radiolink is calculated based on set of

parameters separately for real -time (MaxRTDLPower) andnon-real-time services (MaxNRTDLPower). For information onthe parameters related to the calculation, see AdmissionControl. As an example, Table Example of DL link powersshows DL link powers for different services.

Table 8. Example of DL link powers

Speech service, kbps Packet services, kbps

Bit rate 4.75 5.9 7.95 12.2 64 128 384

Max DLlink power(dBm)

32.3 32.7 33.2 34.2 37.8 40.0 40.0

In this example, Max total TX power is 20 W, PtxDPCHmax is -3 dB, PtxPrimaryCPICH is 33 dBm, andCPICHtoRefRABOffset is 0 dB.

. Downlink EIRP

Downlink EIRP = MaxRT/NRT)DLpower -Cableloss -MHAinsertionloss + Transmit Antenna Gain

4. Calculate or estimate downlink load factor using WCDMA downlinkload equation:



ηDL Downlink load factor, generally downlink loadof 0.5 _ 0.8 is used in dimensioning

N Number of users

Vj L1 activity factor of user j (0.67 for voice ul,0.63 for voice dl, 1.0 for data)

Eb/Noj Received Eb/No of user j

W WCDMA chip rate; 3.84 Mcps/s

Rj Data rate of user j

α Orthogonality dependant upon the propagationchannel condition (commonly selected to 0.5(can vary between 0.4 to 0.9)

i Ratio of other to own cell interference. Thevalue depends on the BTS sectorisation:. Micro cell: Omni: 25% - 55%. Macro cell: Omni: 55%, 2-sector: 55%, 3-

sector: 65%, 4-sector: 75%, 6-sector:85%

It is recommended to use the maximum downlink load of 0.5–0.8,even if in the initial phase of the network the subscriber traffic wouldnot generate as much load. This is to avoid a situation where slightincreases in traffic amounts may cause shrinkage of the coverageareas. In rural areas, where major traffic is not expected, lower uplinkload value may be used.

Interference margin is calculated similarly as in uplink.

5. Define Interference Floor.

Calculate thermal noise as in uplink link budget.

Interference_floor = Thermal noise + Handset noise figure +interference_margin

6. Define receiver thermal sensitivity.

Receiver thermal sensitivity is computed according to the followingequation. Use downlink Eb/No values.

Receiver Sensitivity = Interference_floor + Required Eb/No -Processing Gain

7. Define additional parameters.

=DL

Eb / Noj

W / R j

vj

j=1

j=N

* (1 - + i)(1 + SHO_OH) *

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. DL fast fading margin. In DL fast fade margin is assumed to be0 dB in the downlink direction as a result of the limiteddownlink transmit power control dynamic range.

. Gain against shadowing. In R99 DL DCH, the recommendedvalue is 2.5 dB, which is used to determine the selectionpossibility of stronger cell in normal cell overlapping network

. DL SHO gain represents a reduction in Eb/No requirementwhen the UE is in soft handover state. The recommended celledge value is 2.5 dB (in capacity calculation DL SHO gain is1.2 dB as an average over the cell, for UL SHO gain isneglected in the capacity calculation).

8. Define clutter-related parameters.

Set these parameters as in uplink link budget.

9. Define the isotropic power required. Required signal power iscalculated to take into account the building penetration loss andindoor standard deviation, as well as receiver sensitivity andadditional margins.

Isotropic power required = Receiver sensitivity - RxAntennaGain +Body loss + DL fast fading margin – DL SHO gain – Gain againstshadowing + BPL + Shadowing margin

10. Define allowed propagation loss.

Allowedprop.loss = EIRP - Isotropic power required

3.2.3 Cell range and coverage

As shown, the link budget can already include the margins, for example toidentify the allowed propagation loss in indoor location.

The cell range calculation can be calculated by using either uplink ordownlink path loss. Most commonly the uplink path loss is used tocalculate the coverage. But in network dimensioning, the link budgetcalculation has to be made for every service, and the limiting one has to beselected for the cell range.

The cell range and coverage is based on:

. system parameters as shown in link budget

. taking into account margins to guarantee service for example, inindoor, in-car or outdoor

. building penetration loss, car penetration loss or outdoor when nopenetration loss



. location probability

. standard deviation

. calculating the cell range by using propagation model like Okumura-Hata model when also noticing the

. frequency, for example, 2100 MHz

. Node B antenna height, for example, 30 meters

. UE antenna height, for example, 1.5 meters

. Clutter correction factor, which is related to the type of clutter. As anexample Dense urban (3…0 dB), Urban (0…-3 dB) and Suburban (-5…-8 dB).

For example, in urban macro environment, Node B antenna height is30 m, MS antenna height is 1.5 m and carrier frequency is 1950 MHz

L = 137.4 + 35.2*log(R).

Where L is the path loss and R is the range in kilometres. Forsuburban we can assume clutter correction factor for example, 8 dBand calculate the path loss as follows:

L = 129.4 + 35.2*log(R).

. Indoor cell range (taking into account the speech UL path loss)

R = 10^((142.5-137.4) / 35.2) = 1.4 km

. Node B coverage area calculation (depending on the number ofsectors in Node B)

A=K*R2

K-factor; depending on the Node B sectorisation:

Figure 4. Node B sectorisation

R

OmniA = 2,6 R1

R

Bi-sectorA = 1,73 R2

R

R

Tri-sectorA = 1,95 R3

2 2 2

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3.3 R99 DCH capacity dimensioning

3.3.1 Load calculation based on traffic inputs

To calculate whether the capacity of coverage Node Bs supports the trafficestimation, you should estimate the load factor from the traffic. Also the ULload factor has to be calculated, as HSUPA utilises the load which is leftfrom DCH traffic.

To calculate the maximum number of simultaneous uplink/downlink usersin a cell, you can utilise the following method where the subscribers percarrier per cell are calculated from the total number of subscribers, thenumber of Node Bs and the configuration of those Node Bs. The equationused is as follows:

Total traffic is calculated over the subscribers, and after that you cancalculate the needed traffic channels per cell.

For voice and RT data services the traffic channel calculations are basedon the Erlang B formula and for NRT data services they are based onthroughput. The two equations are given here:

Voice and RT data

Uplink: UL_tchs = ErlangBchs(bloc_prob;traffic)

Downlink: DL_tchs = UL_tchs x (1 + Soft_HO_oh)

The blocking probability is typically assumed to be 2%. Soft_HO_oh canvary from 20-40%.

NRT data

For NRT, the activity for downlink and uplink can be different, and the needfor traffic channels can vary. Commonly UL and DL traffic is 1:10.

Uplink:

Subscribers per carrier per cell =Total number of subscribers

No. of Node B * No. of cells per Node B * No. of carriers per cell

tchs =traffic

throughput * R



Downlink:

In the equation, R is the service bit rate. The throughput is assumed to be79%. This figure includes the L2 re-transmission overhead of 10% and15% of buffer headroom to avoid overflow (peak to average load ratioheadroom) => (1+0.10) x (1+0.15) = 1.265 => 26.5% overhead =>throughput is 79% of user traffic. Soft_HO_oh can vary from 20% to 40%.

The fractional load generated by the services can then be calculated fromthe UL and DL load formulas wherein noticing the SHO gain (also calledMDC gain) and the number of interfering channels. In UL/DL the gain isdue to soft handover which influences the Eb/No. The reduction in Eb/Nois commonly assumed to be 0 dB in UL and 1.2 dB in DL.

Uplink fractional load formula

The formula for uplink fractional load is as follows:

where

. m is the number of interfering channels

. Eb/No is the target energy per bit to interference spectral densityratio

. W is the chip rate

. R is the bit rate

. SHOgain_UL is the average macro diversity gain on the UL due tosoft handover which reduces the Eb/No

tchs =traffic

throughput * R* (1+ Soft_HO_oh)

fL_UL=m * (1+ i_UL*PowerRiseUL)

W1 +

R*10

Eb / N0_BTS-SHOgain_UL

10

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. PowerRiseUL is the average increase in transmit power due topower control.

. i_UL is the ratio of other to own cell interference.

The total UL load is obtained by summing the UL fractional loads over allservice classes.

Downlink fractional load formula

The formula for downlink fractional load is as follows:

where

. m is the number of interfering channels

. Eb/No is the target energy per bit to interference spectral densityratio

. W is the chip rate

. R is the bit rate

. SHOgain_UL is the average macro diversity gain on the UL due tosoft handover which reduces the Eb/No

. Orth_DL is the downlink orthogonality

. i_DL is the ratio of other to own cell interference.

The total downlink load is obtained by summing the downlink fractionalloads over all service classes.

3.3.2 DL power calculation vs. load

Node B has a maximum power from which it allocates for control channelsand traffic channels. If the load is higher, also the interference from thecontrol channel is higher and causes power increase related to the load.Total power is basically calculated as shown in the formula below:

Ptot_tx=PCCH_tx+PDCH_tx

fL_DL=m * * (1 - Orth_DL + i_DL)

W

10

Eb / N0_MS-SHOgain_DL

10 * R



where

. Ptot_tx is the total transmission power

. Pcch_tx is the control channel power

. Pdch_tx is the traffic channel power

When going into details, the formula also includes the DL load factor. Inthat case the formula is as follows:

where

. PN is the noise power

. Lp is the average path loss = Isotropic Path Loss – Antenna gain –Cable loss + SHO gain – IPL correction factor

. Other parameters are the same as in the DL load formula.

Ptot_tx=

1- DL_DCH

PCCH_tx+ PN * L P

(Eb / No) j

W / R j* Vj*

j

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4 HSDPA dimensioning

4.1 Introduction to HSDPA dimensioning

HSDPA downlink data is carried on a shared channel. For this reason,different variables have to be considered in HSDPA dimensioningcompared to NRT DCH data bearer dimensioning. The most importantdimensioning target for HSDPA is the average throughput. The achievedaverage throughput depends on the amount of power allocated forHSDPA.

The aim of the HDSPA air interface dimensioning is to specify how muchpower should be allocated for HSDPA. HSDPA power should be enough toachieve HSDPA throughput targets, but on the other hand, enough powerresources should be reserved for the DCH traffic as well.

If DCH load is high, the shared carrier HSDPA+DCH is not feasible to fullysupport the growing data traffic in HSDPA, especially now when HSUPAcreates even higher demand to support data traffic. In case of high DCHload, a dedicated carrier for HSPA (HSDPA + HSUPA) is needed. In thiscase the capacity of the carrier is allocated fully to HSDPA (see FigureOverall dimensioning process for dedicated HSPA carrier in Introduction toHSUPA dimensioning.

Figure Dimensioning process with DCH + HSDPA (+ HSUPA) shows thedimensioning process with shared carrier, either with or without HSUPA .From HSDPA point of view, the process is the same.

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HSDPA dimensioning

Figure 5. Dimensioning process with DCH + HSDPA (+ HSUPA)

The dimensioning process of HSDPA is basically as in R99; the first step iscoverage dimensioning, followed by capacity dimensioning. However, theprocess differs in that capacity dimensioning has to include also the R99capacity estimation if shared carrier is in use.

The steps for air interface HSDPA dimensioning are:

Coverage dimensioning

Coverage dimensioning can be based on:

. R99 service link budget

. HSDPA link budget with selected cell edge throughput

. (n case HSUPA, HSUPA link budget with selected cell edgethroughput

Air interface dimensioning,dedicated carrier HSPA


- Link Budget UL R99(based on HSDPAassociated UL DPCHservice)- Link Budget HSDPA(based on cell edgethroughput)- Link Budget HSUPA(based on cell edgethroughput)- Output # of coverage sites UL DPCH capacity

dimensioning

Resultevaluation

CECalculation


Iu-bDimensioning

RNCDimensioning




Input: capacityfor HSUPA

Output:HSUPAthroughput

OK

Not OK

Output:HSDPAthroughput

Input:availablecapacity# of

Node Bs(coverage +capacity)


Input:availablecapacity



Capacity dimensioning

. Estimate and calculate R99 traffic and capacity demand based ontraffic and subscriber profile inputs.

. Estimate HSDPA capacity from capacity left after R99 traffic.

. (Estimate HSUPA capacity from capacity left after R99 traffic).

. If R99 and/or HSDPA (+HSUPA) capacity is not enough, you can:. Add new Node Bs. Tune the parameters in link budget or capacity-related feature

parameters. Add dedicated carrier for HSPA.

The expected outcome from the HSDPA dimensioning is as follows:

. Defining the HSDPA cell range and coverage based on cell edgethroughput or utilise the existing R99 service link budget to definewhat kind of HSDPA throughput can be achieved at the cell edge

. Calculating the average cell throughput based on power available forHSDPA

. Identifying the Node B configuration required to achieve a specificthroughput performance

For more information on HSDPA, see High-speed Downlink PacketAccess (HSDPA) in HSPA Overview.

4.1.1 HSDPA features in RAS06

RAS06 introduces the following HSDPA features:

. RAN1013: 16 kbit/s Return Channel DCH Data Rate Support forHSDPA

. RAN852: HSDPA 15 Codes

. RAN1033: HSDPA 48 Users per Cell

. RAN853: HSDPA Code Multiplexing

. RAN1034: Shared HSDPA Scheduler for Baseband Efficiency

. RAN1011: HSPA Layering for UEs in Common Channels

. RAN312: HSDPA Dynamic Resource Allocation

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HSDPA dimensioning

For more information, see RAS06 Feature Descriptions.

See also Radio Resource Management of HSDPA and HSDPA in BTS

4.1.2 Supporting R99 formulas

Due to the shared carrier, HSDPA needs to take into account the powergenerated by R99.

The HSDPA capacity calculation takes into consideration the Node B TXpower used for R99 services. As noticed in the Dynamic ResourceAllocation feature, the rest of the power after DCH traffic, HSUPA controlchannels and common channels is used for HSDPA. This means that tofind how much the power is left for HSDPA, it is necessary to make the DLpower calculation vs. load. Based on this information, the availableHSDPA power can be used to determine the HSDPA capacity. This isneeded if HSDPA has a shared carrier with R99 traffic.

4.2 HSDPA coverage dimensioning


The UL data of the HSDPA connection is carried on associated DPCH,which is a normal NRT data bearer. The supported data rates forassociated DPCH are 16, 64, 128 and 384 kbps.

However, additional margin is required in the UL link budget to take intoaccount the power requirements of HS-DPCCH. HS-DPCCH carrieschannel quality information (CQI) reports and Ack/Nack feedback forHARQ.

HS-DPCCH is power controlled relative to the every slot period in uplinkDPCCH. The power offset parameters (ΔACK; ΔNACK; ΔCQI) arecontrolled by the RNC and reported to the UE using higher layer signalling.The HS-DPCCH power offset must be increased, since the UL HS-DPCCH power control is sub-optimal for HSDPA users in soft handovermode (that is, active set size larger than one). It is possible that thedominant link in the active set is not the one belonging to the cell which iscurrently transmitting the HS-PDSCH to the user. However, using themaximum HS-DPCCH power offset of 6 dB is not sufficient to ensure good



UL HS-DPCCH quality under all conditions, unless Ack/Nack repetition isused. The average overhead generated by HS-DPCCH depends on ACK/NACK and CQI activity. Link budgets consider peaks rather than theaverage overhead.

Figure 6. HS-DPCCH power offset parameters

The additional margin in UL link budget due to CQI reports and Ack/Nackdepends on the UL bearer data rate:

. UL 16 kbps: 4.6 dB

. UL 64 kbps: 2.8 dB

. UL 128 kbps: 1.6 dB

. UL 384 kbps: 1.1 dB

Overall, the HSDPA-associated UL link budget corresponds to the R99 ULlink budget for packet services. The only difference is the HS-DPCCHoverhead, and it can be included in the EIRP formula:

uplinkEIRP = UE Transmit Power - HS_DPCCHoverhead + TransmitAntenna Gain - BodyLoss


For downlink, the link budget can be used to calculate the cell range withrelated coverage requirements such as cell edge throughput. There aretwo most important link budgets in HSDPA that are for user and controltraffic. Table HSDPA downlink link budget for HS-PDSCH and HS-SCCHshows an example of both link budgets (HS-PDSCH and HS-SCCH).

HS-DPCCH

DPCCH

Ack/Nack CQI report

ACKi CQINACK CQI

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HSDPA dimensioning

Table 9. HSDPA downlink link budget for HS-PDSCH and HS-SCCH

Downlink Service

Cell Edge Throughput 384

Channel HS-PDSCH HS-SCCH

Service PS Data Control

Service Rate (kbps) 384

Transmitter - Node B

Max Tx Power (dBm) 37.4 27

Cable Loss (dBi) 0.5 0.5

MHA Insertion Loss 0.0 0.0

Tx Antenna Gain (dBi) 18 18

EIRP (dBm) 54.9 44.5

Receiver - Handset

Handset Noise Figure (dB) 7 7

Thermal Noise (dBm) -108 -108

Downlink Load (%) 80 80

Interference Margin (dB) 7.0 7.0

Interference Floor (dBm) -94.0 -94.0

SINR Requirement (dB) 4.5 1.5

Spreading Gain (dB) 12.0 21.0

Receiver Sensitivity (dBm) -101.5 -113.5

Rx Antenna Gain (dBi) 2 2

Body Loss (dB) 0 0

DL Fast Fade Margin (dB) 0 0

DL Soft Handover Gain (dB) 0 0

Gain against shadowing (dB) 2.5 2.5

Building Penetration Loss(dB)

12 12

Indoor Location Prob. (dB) 90 90

Indoor Standard Dev. (dB) 10 10

Shadowing margin (dB) 7.8 7.8

Isotropic Power Required(dB)

-86.3 -98.2

Allowed Prop. Loss (dB) 141.2 142.7



HSDPA throughput depends directly on the radio channel conditions.These conditions change rapidly due to fast fading of the radio channel.BTS is able to change the link adaptation for each 2ms TTI based on thechannel measurements. This means that the achieved throughput isdifferent in every TTI. The average throughput in a certain location can beestimated if the average SINR (Signal to Interference + Noise Ratio) isknown. Commonly simulation results are used for estimating the averageSINR. Figure Throughput and SINR comparison shows the SINR andthroughput table with different codes.

Figure 7. Throughput and SINR comparison

-10 -5 0 5 10 15 20 25 30 35 400

2

4

6

8

10

12

SINR(dB)

Throughput(M

bits/s)

5 codes, PedA

5 codes VehA

5 codes fit

10 codes PedA

10 codes VehA

10 codes fit

15 codes PedA

15 codes VehA

15 codes fit

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HSDPA dimensioning

As shown in the figure, in lower throughputs there is no huge advantage ofusing 5, 10 or 15 codes, and also the average SINR is roughly the same.Using average SINR gives a possibility to create a DL link budget forHSDPA. The reason to use SINR is that the HSDPA bit rate and thenumber of codes can change in every TTI. Using Eb/No or Es/No in thelink budget would require that either the bit rate or the number of the codesis known. The bit rate at cell edge is commonly lower than 384 kbps.

From the HS-SCCH link budget point of view, it is most important toestimate the power allocated to it, because that also affects the HSDPApower that is left for traffic. HS-SCCH depends on the user location and iscommonly assumed to be about 500 mW at the cell edge (around G-factor-5 dB).

Figure 8. User location versus HS-SCCH

As discussed, the link budget has to consider the cell edge throughput toget the average SINR, and HS-SCCH has to be estimated to calculate thepower left for HSDPA traffic. Similarly in case of shared carrier betweenthe DL DCH and HSDPA, also the DCH power has to be estimated andtaken into account.

0

Avg.req.HS-SCCHpower@

1%

BLEP[W

]

-15 -10 -5 0 5 10 15

0.5

1.0

1.5

2.0

2.5

3.5

4.0

3.0

NODE-B/CPICH POWER 12W/2W1x1-RAKE, 3KM/H, 6MS/1DB LA DELAY/ERROR

Typical macrocellularenvironment (3GPP)

Average G-factor [dB]

Ped-AVeh-A



Defining downlink link budget

The parameter definition is the same as for R99 uplink DCH link budget,but with some differences, described here.

1. Define service parameters.. Service rate. You can define the throughput for HSDPA to

calculate the allowed propagation loss. This affects the SINRrequirement, which is needed for getting the wanted service atcell edge.

2. Define UE parameters.

Define RX Antenna Gain and Handset Noise Figure. CommonlyBody Loss is assumed to be 0.


Available HSDPA power notices also HS-SCCH power and in caseof shared carrier with DCH, the DCH power has to be noted as well.

Note that feature RAN312: HSDPA Dynamic Resource Allocationdescribes HSDPA power in more detail.

4. Additional differences compared to the R99 DCH downlink linkbudget.. HSDPA utilises only spreading factor 16.. Receiver sensitivity formula

Receiver Sensitivity = Interference_floor +SINR - SpreadingGain (SF16)

. HSDPA does not have soft handover, thus SHO gain are 0 dB.But because there are overlapping cells, the HSDPA mobilecan select at cell edge a stronger cell, which is referred to asGain against shadowing. The recommended value for Gainagainst shadowing in HSDPA is 2.5 dB.

Other issues, formulas and parameters related to the HSDPA link budgetare same as those for R99. See R99 DCH coverage dimensioning.


From the HSDPA perspective, the cell range and coverage are dependenton available power and wanted cell edge throughput.

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HSDPA dimensioning

Figure 9. Example of dynamic power allocation

As shown in the figure, all available power is allocated to HSDPA. Fromthe dimensioning perspective, it is important to estimate the average non-HSDPA power and calculate the average available power for HSDPA.Based on that you can estimate the coverage. In case of dedicatedHSDPA carrier, DCH traffic power can be neglected. For more informationon dynamic power allocation, see HSDPA dynamic resource allocation inRadio Resource Management of HSDPA.

4.3 HSDPA capacity dimensioning

HSDPA downlink link budget utilises the average SINR and throughputmapping, which are commonly based on the simulations. An accurateSINR can be calculated when you know HSDPA power, BTS total Txpower, orthogonality and G factor and the user throughput can beestimated. The calculation is done using the following formula:

PtxMax

Time

HSDPA power PtxTargetPSMax

PtxTargetPSMin

Non-HSDPA power

PtxTargetPS

PtxMax is the cell maximum output powerdefined by the management parameterPtxCellMax and the BTS capabilityPtxTargetPS is the dynamically adjustedNRT DCH scheduling targetPtxTargetPSMax and PtxTargetPSMin arethe max and min values for PtxTargetPS

SINR = SF16

HSDPAP

totP 1 - + 1

G



where

. PHSDPA = HSDPA Tx power

. Ptot = total WBTS Tx power

. α = DL orthogonality factor

. SF16 = spreading factor of 16

. G = G-factor

G-factor reflects the distance between the MS and the BS antenna. Atypical range is from -5 dB (Cell Edge) to 20 dB. G-factor is correlated toEc/Io:

where

. PCPICH = CPICH channel transmission power

. PTOT = BS total transmission power at the time of Ec/Iomeasurement

When the user SINR is known, the mapping on the simulated table can bemade and the user throughput identified. If you allocate all availableHSDPA power to one user, you can estimate the HSDPA cell throughput ina different location in the cell (ref. G-factor) within different radioenvironment (orthogonality).

Other issues to take into account when estimating the cell throughput are:

. Scheduler type: cell-specific or shared

. Proportional fair resource scheduler usage

. Number of codes used in the cell: 5 or even 15 or something inbetween due to feature HSDPA Dynamic Resource Allocation

Figure Example simulation results of HSDPA cell throughput shows anexample of how the different issues and UE enhancements affect HSDPAcell throughput.

CPICHP

TOTP 1 + 1

G

E

IC

O

=

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HSDPA dimensioning

Figure 10. Example simulation results of HSDPA cell throughput

0

500

1000

1500

2000

2500

3000

3500

4000

4500

Rake 1-ant Equalizer 1-ant Rake 2-ant Equalizer 2-ant

kbps

Round robin 5 codes

Round robin 10 codes

Proportional fair 5 codes





5 HSUPA dimensioning

5.1 Introduction to HSUPA dimensioning

RAS06 provides a new advantage to uplink with HSUPA, which provideshigh data rates in uplink direction for packet services. HSUPA is providedonly in co-existence with HSDPA.

The aim of the HSUPA air interface dimensioning is to specify how muchload should be allocated for HSUPA. HSUPA capacity should be enoughto achieve HSUPA throughput targets, but on the other hand, enoughresources should be reserved for DCH traffic and for HSDPA-associatedUL DPCH.

In case of high DCH load, the shared carrier HSUPA+UL DCH is notfeasible to fully support the HSUPA demand. In high DCH load a dedicatedcarrier for HSPA (HSDPA+HSUPA) is needed. In this case the uplinkcapacity of the carrier is allocated to HSUPA and HSDPA associated ULDPCH, see Figure Overall dimensioning process for dedicated HSPAcarrier.

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HSUPA dimensioning

Figure 11. Overall dimensioning process for dedicated HSPA carrier

As shown in the figure, the UL calculation notices both HSDPA associatedUL DPCH load and HSUPA load. It is important that during dimensioningalso the HSDPA-associated UL DPCH capacity need is noticed andestimated.

The overall process is as described in Introduction to HSDPAdimensioning and so the expected outcomes from HSUPA dimensioningare:

. defining the HSUPA cell range and coverage based on cell edgethroughput

. calculating the average cell throughput based on available load forHSUPA

. identifying the Node B configuration required to achieve a specificthroughput performance.

For more information, see High-speed Uplink Packet Access (HSUPA) inHSPA Overview.

Air interface dimensioning,dedicated carrier HSPA


- Link Budget UL R99(based on HSDPAassociated UL DPCHservice)- Link Budget HSDPA(based on cell edgethroughput)- Link Budget HSUPA(based on cell edgethroughput)- Output # of coverage sites UL DPCH capacity

dimensioning

Resultevaluation

CECalculation


Iu-bDimensioning

RNCDimensioning




Input: capacityfor HSUPA

Output:HSUPAthroughput

OK

Not OK

Output:HSDPAthroughput

Input:availablecapacity# of

Node Bs(coverage +capacity)


Input:availablecapacity



5.1.1 HSUPA features in RAS06

RAS06 introduces the following HSUPA-related features:

. RAN826: Basic HSUPA

HSUPA is supported only with the co-existence of HSDPA.

All cells in the BTS can be enabled for HSUPA.

The maximum number of HSUPA users is 24 per BTS and 19 percell.

The operator can choose to set a lower threshold for the maximumnumber of users per cell and per BTS.

Transmission Time Interval (TTI) of 10 ms is used for maximising theresulting uplink range.

The highest supported user peak data rate on E-DCH is 1.888 Mbps,corresponding to two parallel codes of spreading factor two (2*SF2)and 10 ms TTI. RLC PDU size 320 bit is used. This bit rate isachieved using 59 RLC PDUs per TTI.

HSUPA requires a static reservation of eight CE in WSPC (UltraSiteWCDMA BTS) and eight CE in Flexi Submodule (Flexi WCDMABTS) capacity. The rest of the HSUPA baseband capacity is fullypooled across cells, and also dynamically shared with R99 traffic. Upto two WSPCs (in Flexi Submodules) can be in HSUPA use, R99traffic allowing.

The maximum peak data rate per user is 2.0 Mbps as coded L1 bitrate (error protection coding is not counted into bit rate whereas L1retransmissions are).

One WSPC in UltraSite WCDMA BTS and one Submodule in FlexiWCDMA BTS supports up to 12 – 24 HSUPA users, depending onthe data rate.

The maximum HSUPA bit rate per WSPC (Submodule in FlexiWCDMA BTS) is 6 Mbps, with three 2 Mbps users in separate cells.

. RAN973: HSUPA Basic RRM

. RAN968: HSUPA BTS Packet Scheduler

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HSUPA dimensioning

. RAN970: HSUPA Handovers

. RAN974: HSUPA with Simultaneous AMR Voice Call

For more information, see RAS06 Feature Descriptions.

See also Introduction and feature structure of Radio ResourceManagement of HSUPA in Radio Resource Management of HSUPA.

5.1.2 Supporting R99 formulas

Due to the shared carrier case the HSUPA has to take into account theload generated by R99, which can be due to pure DCH UL traffic orHSDPA associated UL DPCH traffic.

The HSUPA capacity calculation takes into a consideration the DL loadused for R99 services and HSDPA-associated DPCH. This means that it isnecessary to make load calculation based on traffic inputs to find out howmuch load is reserved for R99 and associated UL DPCH. Based on thisinformation the available UL load can be used to determine the HSUPAcapacity. This is needed if the HSUPA has shared carrier with R99 traffic. Ithas to be taken into account also when dedicated HSPA carrier is used,because the HSDPA-associated UL DPCH utilises the UL load withHSUPA.

5.2 HSUPA coverage dimensioning


As shown in Table Example of HSUPA link budget, the HSUPA link budgetis very similar to the R99 uplink packet service link budgets, especiallyregarding HSDPA associated UL bearer. The major differences are relatedto higher user throughputs, which generate higher own connectioninterference. Also the Eb/Nos used are better when compared to DCH.This is due to Node B based HARQ, which allows to tolerate additionalpacket losses and retransmissions without causing problems from thedelay perspective.



Table 10. Example of HSUPA link budget

Uplink Service

Cell Edge Throughput(kbps)

64

Target BLER (%) 10

Propagation Channel Pedestrian A 3 km/h

Channel HSUPA

Service PS Data

Service Rate (kbps) 64

Transmitter - UE

Max Tx Power 24

HS-DPCCH Overhead 2.5

Tx Antenna Gain (dBi) 2

Body Loss (dB) 0

EIRP (dBm) 23.5

Receiver - Node B

Node B Noise Figure (dB) 2


Uplink Load (%) 50

Interference Margin (dB) 3.0

Own ConnectionInterference

0.08

InterferenceFloor (dBm) -103.1

Service Eb/No (dB) 0.2

Service PG (dB) 17.78

Receiver Sensitivity (dBm) -120.65

Rx Antenna Gain (dBi) 18

Cable Loss (dB)s 0.5

Benefit of using MHA (dB) 0

UL Fast Fade Margin (dB) 1.8

UL Soft Handover Gain(dB)

1.5

Gain against shadowing(dB)

2.5

Building Penetration Loss(dB)

12

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Table 10. Example of HSUPA link budget (cont.)

Uplink Service

Indoor Location Prob. (dB) 90

Indoor Standard Dev. (dB) 10

Shadowing margin (dB) 7.8

Isotropic Power Required(dB)

-120.6

Allowed Prop. Loss (dB) 144.0

Own connection interference has been neglected from R99 uplink linkbudget as it has such a low impact on system performance. This is mainlyrelated to the fact that uplink 64 kbps service is commonly used in R99dimensioning, and other to own interference is very low, around 0.08. InHSUPA, the link budget can be made even with throughputs higher than0.5 Mbps, which creates more interference.

Defining uplink link budget

The parameter definition is similar to R99 uplink DCH link budget.However, there are the following differences:

1. Define service parameters.. Service rate. You can define the throughput for HSUPA to

calculate the allowed propagation loss. This affects the Eb/Novalue.

The following table shows the simulated Eb/Nos for HSUPA.

Table 11. Simulated Eb/Nos for HSUPA

Pedestrian A 3 km/h

10 % BLER

Vehicular A 30 km/h

10 % BLER

Bit rate (kbps) Eb/No (dB) Bit rate (kbps) Eb/No (dB)

32 0.8 32 2.3

64 0.2 64 1.6

128 -0.2 128 0.8

256 -0.5 256 0.4

384 -0.5 384 0.4

512 -0.7 512 0.1

768 -0.7 768 0.1



Table 11. Simulated Eb/Nos for HSUPA (cont.)

Pedestrian A 3 km/h

10 % BLER

Vehicular A 30 km/h

10 % BLER

Bit rate (kbps) Eb/No (dB) Bit rate (kbps) Eb/No (dB)

1024 -0.2 1024 0.6

1440 1.3 1440 2.1

. HS-DPCCH overhead. As mentioned in HSDPA uplink linkbudget, the same HS-DPCCH overhead is implemented inHSUPA, which is dependent on the bit rate. The following tableshows the overhead values for soft handover and without softhandover.

Table 12. HS-DPCCH overhead for HSUPA

SHO Bit Rate (kbps) 35.4 69 102.6 169.8 474 810 1146

DS-DPCCHOverhead (dB)

3.03 2.46 1.93 1.27 0.087 0.60 0.39

No SHO Bit Rate (kbps) 35.4 69 102.6 169.8 474 810 1146

DS-DPCCHOverhead (dB)

1.48 1.16 0.88 0.55 0.37 0.25 0.16

. HSUPA EIRP. You can calculate HSUPA EIRP using thefollowing formula:

HSUPA EIRP = UE Transmit Power - HS_DPCCH overhead +Transmit Antenna Gain - Body Loss

2. Define UE parameters.

Define RX Antenna Gain and Handset Noise Figure. Commonlybody loss is assumed to be 0.


Node B parameters are the same as in R99 DCH link budget. SeeR99 DCH coverage dimensioning.

4. Additional differences compared to the R99 DCH uplink link budget

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. Own connection interference. Own connection interferencefactor reduces the uplink interference floor by the UE’s owncontribution to the uplink interference, that is, by the desireduplink signal power. This means that the own connectioncontribution has to be noted in the interference floorcalculation. The formula for calculating own connectioninterference contribution is as follows:

. Interference floor. Based on the above mentioned modificationthe interference floor is calculated as follows:

Interference_floor = Thermal noise + Node B noise figure +interference_margin - own_connection_interference

Other issues, formulas and parameters related to the HSUPA link budgetare the same as the link budgets in R99. See R99 DCH coveragedimensioning.


HSUPA connections make use of HSDPA in the downlink direction. For theSRB, DPCH 3.4 kbps is needed.


From the HSUPA perspective, the cell range and coverage are dependenton uplink link budget and defined cell edge throughput.

By defining the cell edge throughput, the Eb/No will be selected and theoverall link budget and cell range estimation are as in R99 DCH linkbudget.

HSUPA has additional features that affect the cell range. One whichaffects the load generated to the cell and also the cell range is then higherdue to the lower interference margin.

Own_connection_int = 10LOG 1+

Eb

No

W

R



5.3 HSUPA capacity dimensioning

Capacity dimensioning can include one user throughput estimation orwhole cell throughput estimation. The following issues affect capacitydimensioning:

. Available load for HSUPA

. User location

. Number of users

. Load equation parameters, that is, intercell interference ratio whichdepends on sectorisation

Follow these steps to perform HSUPA capacity dimensioning.

1. Estimate the uplink load of DCH users and define the target uplinkload margin.

As mentioned earlier, HSUPA capacity dimensioning has to take intoaccount also the capacity used for R99 DCH traffic. If the R99 uplinkload is 36 % and the maximum target UL load is set to 80 %, HSUPAcapacity is 80%-36% = 44%. This 44% can be used to define thecapacity for HSUPA. Figure Load estimation for R99 DCH andHSUPA shows the load estimation between R99 DCH and HSUPA.

Figure 12. Load estimation for R99 DCH and HSUPA

0

2

4

6

8

10

12

IncreaseinInterference(dB)

Uplink Loadgenerated byR99 DCH

Uplink Loadavailable forHSUPA UE

0 20 40 60 80 100

Uplink Load (%)Example TargetUplink Load

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As shown in the figure, it is important to estimate the R99 load inuplink in order to define the HSUPA capacity. To calculate the loadused in R99 DCH traffic you can utilise the formula discussed inSupporting R99 formulas.

The uplink load is translated to uplink C/I using the uplink loadequation:

C/I is translated to HSUPA bit rate using the Eb/No look-up tablederived from link level simulations.

This information can be used to estimate the throughput in the areawith estimated parameters. To go into more detail, the available loadcan be divided into expected amount of HSUPA users.

2. Divide the available uplink load between the expected number ofHSUPA users.

The available HSUPA load has to be divided equally to everyHSUPA user. When increasing the number of users, each user willhave lower throughput due to the decreasing available load, thusinfluencing at the end the C/I. As a result of this step, all users willhave the same available load and also the same C/I.

To go into more detail, also the estimated HSUPA user location canbe used to estimate user throughput.

=



3. Estimate the link losses between the expected locations of HSUPAusers and the BTS. This way you can get the average cellthroughput by estimating the share of bad coverage HSUPA usersand good coverage users, for example. Figure Example of HSUPAuser distribution on cell area shows an example distribution of fiveusers.

Figure 13. Example of HSUPA user distribution on cell area

The location can be estimated by introducing path loss offsets todetermine the path loss for each UE. C/I can be calculated asfollows.

where. Wanted signal is the signal strength which is calculated from

the link budget, assuming that the UE is transmitting atmaximum power. The path loss offset can be introduced todetermine the user location from the cell edge.

. Interference floor is calculated as:

Interference_floor = Thermal noise + Node B noise figure +interference_margin

4. Verify that the user receives the service.

0.0

500.0

1000.0

1500.0

2000.0

2500.0

3000.0

3500.0

4000.0

0.0 1000.0 2000.0 3000.0 4000.0

UE5

UE4

UE3

UE2

UE1

antenna

link budgetprovidesthe cell edgepath loss

ylocation

x location

C / I = 10xLOGWantedSignal

Interf.Floor - WantedSignal

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If the UE furthest from the cell cannot achieve the equal share C/I(step 2.), their share of the uplink load is decreased to correspond totheir maximum achievable C/I, and you can utilise the load with otherusers who can achieve the level.

As a result of capacity dimensioning, you can:

. estimate the user throughput based on its location and available load

. estimate user throughput based on C/I estimation

. estimate the cell throughput based on users equal load and C/I

. estimate the cell throughput based on different user location, whichcan influence the load and C/I.



6 Dimensioning transport networkPurpose

The most critical task in dimensioning a transport network is to find atransmission solution for the connection between the transmission networkand the base station site. The network rollout can depend on how fast thisconnection can be built. Leasing a Time Division Multiplexing (TDM) orAsynchronous Transfer Mode (ATM) line can be very expensive and time-consuming. Microwave radio links can be more efficient if you build yourown network and copper or fibre-based options are not available. Theradio links can be either point-to-point or point-to-multipoint solutions.

Before you start

Note that the introduction of HSDPA means initially a moderate capacityincrease on each HSDPA-enabled base station. Iub efficiency featuressuch as BTS AAL2 Multiplexing help operators to more efficientlyimplement HSDPA if more than one active WAM is utilised. If an ownmicrowave radio network is chosen, environmental factors such as line ofsight, restrictions in building permissions or access to microwave radiofrequency licences may have an impact.

Check:

. the number of subscribers

. the number of services per subscriber.

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Summary

Figure 14. Dimensioning transport network

Steps

1. Calculate the required transport network capacity.

Calculate the required transmission capacity for the BaseTransceiver Station (BTS) and Radio Network Controller (RNC).

The needed transport network capacity depends on the radionetwork configuration, which again is based on the estimatednumber of the subscribers and services that the subscribers use.

2. Select transport network media.

Depending on the environment and network configuration, you canchoose from cables, radios, and leased lines. Check thegranularities and capacities offered in radio links, fibre, and leasedlines.

Services persubscriber

Requiredtransmissioncapacity/RNC

Requiredtransmissioncapacity/core NW

Transmission network planning(capacity, media, topology, protection...)

QoS requirementsfor the traffic

Radio networkplanning

Number ofsubscribers



3. Plan transport network topology.

Topology options are:. point-to-point. chain. loop. tree. mesh

4. Plan transport network protection.

Transport network protection can be achieved by:. securing the connections, so that information is transferred via

two different routes (requires loop or mesh topology). equipment redundancy, which means that if the equipment

fails, the broken equipment is switched off and a newequipment is taken into use.

Expected outcome

. transmission topology

. capacity of the transmission connections between the nodes in thetransmission network

Further information

You can purchase Nokia planning services for dimensioning transportnetwork.

See also Planning synchronisation in Planning WCDMA RAN.

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7 Dimensioning BTS

7.1 Dimensioning Flexi WCDMA BTS

A new Base Transceiver Station (BTS) type called Flexi WCDMA BTS hasbeen available since RAS05.1. Flexi Wideband Code Division MultipleAccess (WCDMA) BTS is a new, truly modular, very compact, and highcapacity wide-area WCDMA BTS that can be used in various indoor andoutdoor installation options (such as floor, wall, stand, pole, mast, cabinet,19" rack) and site applications (mini, macro, and distributed site solution).This solution can also be used as a multimode upgrade to existing NokiaUltraSite EDGE BTS with WCDMA carriers.

Flexi WCDMA BTS consists of the following self-supporting BTS modules:

. Radio Module, which provides the Radio Frequency (RF)functionality.

. System Module, which provides baseband processing as well ascontrol and transmission functionalities.

System Module provides up to 240 CE capacity. The number of CEsactivated can be increased by licence control.

HSDPA is activated in the Flexi WCDMA BTS dynamically, and thecapacity reserved for HSDPA is defined using features SharedHSDPA Scheduler for Baseband Efficiency and HSDPA 48 Usersper Cell. One to six cells may have HSDPA activated with FlexiWCDMA BTS.

The baseband Extension Module is also available, increasing FlexiWCDMA BTS capacity to 2*240 = 480 CE.

. Optional power supply module.

Optional Outdoor Cabinet is also available.

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Figure 15. Flexi WCDMA BTS modules

7.1.1 Capacity

Flexi WCDMA BTS provides 12-carrier capacity. Up to six sectors and fourcarriers per configuration are supported by HW. The output power optionsmin 8/20/40W are available. The following Flexi 20/40 W per carrierconfigurations are available: 1, 1+1, 1+1+1, 2, 2+2, 2+2+2 and 2+1+1. 1omni configuration is also available with 8W option.

One Radio Module can support one or two sectors. For 1+1+1 (min 40Wper carrier) or 2+2+2 (min 20W per carrier) configurations one SystemModule and two Radio Modules are required for a complete a WCDMABTS setup. Baseband capacity of the system module can be addedremotely with a SW license when needed.

RAS06 (WBTS4.0) Flexi WCDMA BTS System Module capacity is:

. 240 CE, no common channels

. 240 CE - 26 CE = 214 CE with 1-3 cells (26 CE needed for CCCHs)

. 240 CE - 52 CE = 188 CE with 4-6 cells (52 CE needed for CCCHs)

ExtensionSystem Module

BTS SystemModule

RF Module

RF Module

RF Module

AC(Optional)

AC > DC BBU



Table 13. Flexi WCDMA BTS (1+1+1) processing capacity

User data CE UL / Min SF CE DL / Min SF

AMR (voice) 1) 1 / SF64 1 / SF128

WB-AMR 2) 1 / SF64 1 / SF128

PS 16 kbps 1 / SF64 1 / SF128

PS 32 kbps 2 / SF32 2 / SF64

PS 64 kbps 4 / SF16 4 / SF32

PS 128 kbps 4 / SF8 4 / SF16

PS 256 kbps 8 / SF4 8 / SF8

PS 384 kbps 16 / SF4 16 / SF8

CS 64 kbps 4 / SF16 4 / SF32

CS 57.6 kbps 4 / SF16 4 / SF32

CS 14.4 kbps 1 / SF64 1 / SF128

1) AMR codecs 12.2, 7.95 and 5.90 and 4.75 kbps supported

2) WB-AMR codecs 12.65, 8.85 and 6.6 kbps supported

7.1.2 Baseband capacity and HSDPA

An example of Flexi WCDMA BTS capacity with HSDPA is presented inthe following table. The table refers to BTS baseband capacity only. In realnetworks, air interface and transport capacity issues have to beconsidered as well. For more information, see Dimensioning Air interfaceand Dimensioning Iub interface.

Table 14. Flexi WCDMA BTS (1+1+1) baseband capacity and HSDPA

Feature 5 codes 15 codes

CE required Maxthroughputper cell

Maxthroughputper BTS

CErequired

Maxthroughputper cell


HSDPA 16 Users per BTS 32 CE 3.6 Mbps 3.6 Mbps n/a n/a n/a

HSDPA 16 Users per Cell 96 CE 3.6 Mbps 10.8 Mbps n/a n/a n/a

Shared HSDPA Schedulerfor Baseband Efficiency(48 users per BTS)

80 CE 3.6 Mbps 10.8 Mbps 80 CE 3.6 (7.2)Mbps

10.8 Mbps

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Table 14. Flexi WCDMA BTS (1+1+1) baseband capacity and HSDPA (cont.)


+with HSDPA CodeMultiplexing feature

n/a n/a n/a 80 CE 10.8 Mbps 10.8 Mbps

HSDPA 48 Users per Cell 240 CE 3.6 Mbps 10.8 Mbps 240 CE 3.6 (7.2)Mbps

10.8 (21.6)Mbps

+with HSDPA CodeMultiplexing feature

n/a n/a n/a 240 CE 10.8(14.4)Mbps

32.4 (43.2)Mbps

The figures in parentheses assume that either 10- or 15-code phones areused in the network.

7.1.3 Capacity licenses

Flexi WCDMA BTS licensed capacity defines the capacity that theoperator has purchased. Licensed capacity can be less than the maximumhardware capacity.

Flexi WCDMA BTS baseband capacities are allocated according to thecapacity license file. Because the ATM Cross-Connection (AXC) and theBTS exist in high volumes in the network, Nokia Siemens Network doesnot generate licenses for these network elements directly (NE licences),but so-called pool licenses are used. This means that the user gets thelicense to use a dedicated amount of features or capacity (pool license)and it is up to the user to determine how these NE licenses are distributedtowards the network elements.

As an example, you buy a pool license for 10.000 code channels for BTSs.You get a pool license file that allows using this capacity. With this poollicense and the help of the license management tools in NetAct you candistribute the capacity according to capacity needs, for example, 120channel elements for BTS-1, 70 channel elements for BTS-2, and so on.For this purpose, NetAct generates appropriate license files anddownloads them to the network elements.

For more information on licences, see Pool licences in LicenceManagement in WCDMA RAN.



7.1.4 Flexi WCDMA BTS and transmission

For the RNC, both Flexi WCDMA BTS and UltraSite WCDMA BTS look thesame. The Asynchronous Transfer Mode (ATM) layer terminates at theWideband Application Manager (WAM) of the UltraSite WCDMA BTSs. InFlexi WCDMA BTSs the termination point is the System Module unit.

7.2 Dimensioning UltraSite WCDMA BTS

Figure UltraSite WCDMA BTS architecture depicts Nokia MetroSite andNokia UltraSite WCDMA BTS units. Wideband Signal Processor A(WSPA) and Wideband Signal Processor C (WSPC) capacities arepresented in WSPA/C processing capacity.

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Figure 16. UltraSite WCDMA BTS architecture

UltraSite WCDMA BTS units are explained in the following table.

Table 15. BTS units

Unit Description

WAF Wideband Antenna Filter. Combines and isolates Tx/Rx signalsand amplifies the received signals. One WAF is required persector.

R-busWAF

WTR RR-bus

RT-bus

T-bus

WPA

WAF

WPA

WTR

DSC-bus

RR-bus

RT-bus

R-busWAF

WTR RR-bus

RT-bus

T-bus

WPA

WAF

WPA

WTR

DSC-bus

RR-bus

RT-bus

R-busWAF

WTR RR-bus

RT-bus

T-bus

WPA

WAF

WPA

WTR

DSC-bus

RR-bus

RT-bus

IFU

WSC

AXU

lub

CarrierInterface

WSCMAIN

WSCREDU

WAM

WAM

WAM

WAM

WAM

WAM

ST-busSR-bus

ST-busSR-bus

ST-busSR-bus

ST-busSR-bus

WSM

WSM

WSM

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP



Table 15. BTS units (cont.)

Unit Description

WPA Power Amplifier. A multicarrier amplifier with an operatingbandwidth of any 20 MHz section on the whole 60 MHz WCDMAallocation (WPAC/D), on a 10 MHz section of two neighbourcarriers (WPAI/J) or on a 15 MHz section of two neighbour carriers(WPAK). The number of WPAs depends on the number of sectors,carriers, Rollout Optimised Configuration (ROC) utilisation, and therequired output power per carrier.

WTR WCDMA Transmitter and Receiver unit. One Wideband Transmitterand Receiver version B or D (WTRB/D) can serve two cells of 2-way uplink diversity, WTRA can serve one cell.

WSM Summing and Multiplexing unit. Sums Tx signals from the signalprocessing units or other WSMs.

WSP Signal Processing unit. Performs Rx and Tx code channelprocessing, coding, and decoding functions. The number of WSPsis planned according to the expected traffic on the BTS. WSPcapacities are presented in Tables WSPA processing capacity andWSPC processing capacity.

WAM Application Manager. There can be up to six WAM units installedin the BTS: Three WAMs act as primary WAMs (WAM in slots Nr.0) and three WAMs act as secondary WAMs (WAMs in slots Nr. 1).

One primary WAM at a time is selected as a Telecom and O&Mmaster unit (Master WAM) by the system. Master WAM unit takescare of the control functions on BTS cabinet level. Those includeBTS start-up, temperature control, configuration, and O&Mprocessing.

All WAM units perform telecom control functions, logical resourcemanagement, ATM processing, and transport channel frameprotocol processing.

AXU Each UltraSite WCDMA and MetroSite WCDMA/50 Base Stationhas an integrated ATM switch, called the ATM Cross-connect(AXC) Node, for communication between the sectors inside theBTS, towards the RNC, and towards other BTSs. The AXU unitperforms the main ATM functionality for the communication withinthe BTS and provides the connections to other network elements.

IFU The IFUs provide the physical connection to the network. Theysupport the following transmission interfaces: E1/JT1, STM-0/STM-1, E1, Nokia Flexbus.

7.2.1 WSPA/C processing capacity

The following table presents the WSPA processing capacity.

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Table 16. WSPA processing capacity

User data rate /kbps

Decodingcapacity

Min SF Encodingcapacity

Min SF

AMR voice 32 64 32 128

16 32 64 32 128

32 16 32 16 64

64 8 16 16 32

128 8 8 8 16

256 4 4 4 8

384 2 4 2 8

The following table presents the WSPC processing capacity.

Table 17. WSPC processing capacity

User data rate /kbps

Decodingcapacity

Min SF Encodingcapacity

Min SF

AMR voice 64 64 64 128

16 64 64 64 128

32 32 32 32 64

64 16 16 16 32

128 16 8 16 16

256 8 4 8 8

384 4 4 4 8

Support for mixed WSPA/C configurations has been available from RAN04onwards.

7.2.2 UltraSite WCDMA BTS baseband capacity and HSDPA

An example of UltraSite WCDMA BTS capacity with HSDPA is presentedin the following table. The table refers to BTS baseband capacity only. Inreal networks, air interface and transport capacity issues have to beconsidered as well. For more information, see Dimensioning Air interfaceand Dimensioning Iub interface.



Table 18. UltraSite WCDMA BTS (1+1+1) baseband capacity and HSDPA


CErequired



CErequired



HSDPA 16 Users perBTS

32 CE 3.6 Mbps 3.6 Mbps n/a n/a n/a

HSDPA 16 Users percell


Shared HSDPAScheduler forBaseband Efficiency(48 users per BTS)


10.8 Mbps

+ with HSDPA CodeMultiplexing feature

n/a n/a n/a 64 CE 10.8 Mbps 10.8 Mbps

HSDPA 48 Users perCell


10.8 (21.6)Mbps

+ with HSDPA CodeMultiplexing feature

n/a n/a n/a 192 CE 10.8 (14.4)Mbps

32.4 (43.2)Mbps

Baseband Capacityand HSPA Sharing


The figures in parentheses assume that either 10- or 15-code phones areused in the network.

7.2.3 Dimensioning steps

1. Dimension the WSP.

The number of WSPs/BTSs is determined by the expected traffic typesand amounts, and the number of HW channels required for the CommonControl Channels (CCCH). The basic capacity unit is Channel Element(CE), corresponding to the processing requirement for one AMR call. TheCE consumption is calculated separately for UL and DL DCH trafficaccording to DCH rates. The following table is applicable for WSP cardtypes A/C, but it is not applicable for common control channel signalling.

Table 19. Required numbers of HW channels per bearer

Bearer data rate (kbps) Required Channel Elements

16 or voice 1

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Table 19. Required numbers of HW channels per bearer (cont.)

Bearer data rate (kbps) Required Channel Elements

32 2

64 Downlink: WSPA 2 / WSPC 4

Uplink: 4

128 4

256 8

384 16

MultiRAB configurations are supported: one MS can have simultaneously,for example, AMR call + 2 PS calls.

2. Dimension the WSP common control channel.

The physical common control channels supported are:

. Physical Random Access Channel (PRACH)

. Common Pilot Channel (CPICH)

. Primary Common Control Physical Channel (Primary CCPCH)

. Synchronisation Channel (SCH)

. Secondary Common Control Physical Channel (Secondary CCPCH)

. Acquisition Indicator Channel (AICH)

. Page Indicator Channel (PICH)

These physical channels are created in the BTS and require certainhardware processing capacities at the BTS.

. WSPA and Common Control Channels

WSPA can support simultaneously the common control channels ofup to four cells. Every reserved cell deducts the available capacityfor dedicated usage by eight channels. In 1+1+1 ROCconfigurations, 24 CEs for CCCHs processing is required.

The WCDMA test loop reserves eight channel elements whenWCDMA test loop is performed.

. WSPC and Common Control Channels

One WSPC is capable of handling one to three cells.



The WCDMA test loop reserves one channel element whenWCDMA test loop is performed.

. Mixed configuration (WSPA/C)

If both different WSP types exist in the same BTS, CCCH isallocated according to the following priorities:

1. Assign all required signalling resources on WSPA.

2. WSPC card is used for signalling if A-type is already loaded ordoes not exist.

3. Allocate WSP DCH.

A single call needs to be processed on a single WSP unit. If the resource isnot available on a single WSP card in the BTS, the system rejects thesetup if a lower bit rate is not suitable for the connection.

For example, a WSPA with 16 channels reserved for signalling has thecapacity of 16 channels for user traffic. These channels are allocated tothe incoming traffic requests until the sum of the used channel elementsreaches 16. Requests exceeding the number of available channels on thatWSP (see Table WSPA processing capacity) are rejected by the BTS ifthere is no free capacity on any other WSP unit in the BTS. However, incase of Real Time (RT) over RT (priority) and RT over Non-Real Time(NRT), the RNC can perform pre-emption type procedures.

For accepting, for example, a PS 128 kbps call the BTS requires four freehardware channels on a single WSP card. If these resources are notavailable, the call is rejected.

Further information

For more information, see Nokia WCDMA RAN BTS configurationprinciples and Introduction to Nokia RAN configurations in ConfiguringWCDMA RAN.

See also UltraSite and MetroSite BTS Commissioning in UltraSiteWCDMA BTS Product Documentation.

7.2.4 HSPA sharing

In case of limited WSPC capacity (typically one WSPC and severalWSPAs in the BTS), HSUPA and 5 codes HSDPA can be allocated to thesame WSPC. No other channels are possible in the HSPA shared card.

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7.3 HSDPA and BTS dimensioning

New schedulers, namely Shared HSDPA Scheduler for BasebandEfficiency and HSDPA 48 Users per Cell, are introduced to support bitrates beyond 3.6 Mbps.

HSDPA with schedulers that allow a maximum of 5 HS-PDSCH codestakes 32 CE capacity in the WSPC / Flexi Submodule that handles HSDPAcells (MAC-hs). Other CEs left can be used for other types of traffic.HSDPA with 15 HS-PDSCH codes takes 64 CE capacity in WSPC and 80CE capacity in Flexi Submodule. No CE is left in the WSPC / FlexiSubmodule for other channels. HSDPA 48 Users per Cell and SharedHSDPA Scheduler for Baseband Efficiency require 64 CE in WSPC and 80CE in Flexi Submodule, with 5 or 15 codes.

The following table gives the maximum numbers of HSDPA schedulersthat can be simultaneously active per scheduler type. Note that only onetype of schedulers can be activated in the BTS at a time.

Table 20. Maximum number of HSDPA schedulers simultaneously active perscheduler type

HSDPA scheduler type Maximum number of schedulers simultaneouslyactive

UltraSiteWCDMA BTS

Flexi WCDMABTS, 1 SystemModule

Flexi WCDMABTS, 2 SystemModules

HSDPA 16 Users per BTS 4* 3* 4

HSDPA 16 Users per Cell 12 3 6

Shared HSDPA Schedulerfor Baseband Efficiency

4* 2* 4*

HSDPA 48 Users per Cell 12 2 5

*) Tcell parameter tuning is required in the RNC.

Associated UL/DL DCH of the HSDPA user requires the capacity in thesame way as normal DCH. Associated UL/DL DCH channels can beallocated to all WSPs / Flexi Submodules. See Table Associated DCHrates and CE usage.



Table 21. Associated DCH rates and CE usage

User dataCE required inUL / Min SF

CE required inDL / Min SF

PS 16 kbps 1 / SF64* 1 / SF128**

PS 64 kbps 4 / SF16 1/ SF128**

PS 128 kbps 4/ SF8 1/ SF128**

PS 384 kbps 16 / SF4 1/ SF128**

*) If SF is 32, 2 CE is required in UL

**) 1 CE for DL signalling is required per HSDPA user

The earlier WBTS3.0/WBTS3.2 HSDPA configurations can still be used,with existing baseband usage for 16 HSDPA users per BTS or 16 HSDPAusers per cell. Capacity is reserved for HSDPA when needed according toHSDPA-related commissioning parameters.

The baseband alternatives are Minimum Baseband Allocation, SharedScheduler for Baseband Efficiency, HSDPA 16 Users per Cell, and HSDPA48 Users per Cell.

Minimum Baseband Allocation

With this scheduler, one WSPC/ Flexi Submodule supports one to threeHSDPA cells. A maximum of 16 HSDPA users per WSPC/ FlexiSubmodule are supported. HSDPA users can be divided freely betweenthree cells. Up to 3.6 Mbps is supported per WSPC/ Flexi Submodule with5 codes and 16QAM. 32 CE is reserved from WSPC/ Flexi Submodule.The bit rate to be allocated to the uplink DCH is 16 kbps, 64 kbps, 128kbps or 384 kbps. Up to 12 HSDPA cells can be served with 4 WSPC forHSDPA.

Shared HSDPA Scheduler for Baseband Efficiency

With this scheduler, a maximum of 48 HSDPA users per WSPC/ FlexiSubmodule are supported. HSDPA users can be divided freely betweenthree cells. Up to 10.8 Mbps is supported per WSPC/ Flexi Submodulewith 5 codes and 16QAM. 64CE is reserved from WSPC and 80 CE fromFlexi Submodule per BTS. The bit rate to be allocated to the uplink DCH is16 kbps, 64 kbps, 128 kbps or 384 kbps. Up to 12 HSDPA cells can beserved with 4 WSPC for HSDPA.

For more information on this feature, see RAN1034: Shared HSDPAScheduler for Baseband Efficiency in RAS06 Feature Descriptions.

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HSDPA 16 Users per Cell

With this scheduler, one WSPC/ Flexi Submodule unit per HSDPA cell isearmarked for HSDPA. This enables a maximum of 16 HSDPA users percell to be supported. Up to 3.6 Mbps with 16QAM is supported per cell. 32CE is reserved from each WSPC or Flexi Submodule. The bit rate to beallocated to the uplink DCH is 16 kbps, 64 kbps, 128 kbps or 384 kbps.

HSDPA 48 Users per Cell

With this scheduler, one WSPC/ Flexi Submodule unit per HSDPA cell isearmarked for HSDPA. The whole card is reserved for HSDPA. Amaximum of 48 HSDPA users per cell are supported. Up to 14.4 Mbps with16QAM is supported per cell. The bit rate to be allocated to the uplink DCHis 16 kbps, 64 kbps, 128 kbps or 384 kbps.

For more information on this feature, see RAN1033: HSDPA 48 Users perCell in RAS06 Feature Descriptions.

For more information, see HSDPA functionality in HSDPA in BTS.

7.3.1 Tcell grouping

RNC parameter Tcell (Frame timing offset of a cell) can be used forgrouping schedulers to cells. For example, the HSDPA 16 Users per Cellfeature requires a processing capacity of 32 CE to be enabled for one tothree cells in the BTS. Another 32 CEs can be added so that cell A ishandled by the first 32 CE and cells B and C by the second 32 CEs. SeeFigure Tcell grouping example, 1+1+1: 2 x32 CE.

Figure 17. Tcell grouping example, 1+1+1: 2 x 32 CE

16 usersTcell = 0

A

B

11 usersTcell = 4

5 usersTcell = 3

Example 1:1+1+1: 2x32 CE



The following figure shows an example with a 2+2+2 configuration.

Figure 18. Tcell grouping example, 2+2+2: 4 x 32 CE

The principles of grouping (maximum 4 groups) are as follows:

. Group 1: Tcell values 0, 1 and 2



. Group 4: Tcell value 9

For more information on Tcell, see also WCDMA RAN ParameterDictionary and HSDPA resource allocations in the BTS inHSDPA in BTS.

7.4 HSUPA and BTS dimensioning

Capacity is reserved for HSUPA on need basis. The capacity reservationmay be changed dynamically between DCH and HSUPA use. In the CEallocation, DCH has a higher priority than HSUPA. HSUPA reserves CEsin uplink and downlink. Additionally, DPCCH for HSPA needs one extra CEper HSUPA user in UL and DL.

HSUPA is supported only with co-existence of HSDPA.

16 usersTcell = 3

16 usersTcell = 6

16 usersTcell = 9

Example 2:2+2+2: 4x32 CE

Tcell = 0 Tcell = 1

Tcell = 2

16 users

f1

f2

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The minimum capacity reserved for HSUPA is 8 CE. In this case, onlyHSUPA MAC-e is active.

With WBTS4.0, at maximum two WSPCs / Flexi Submodules can be usedfor HSUPA. The operator can define the minimum HSUPA-reservedcapacity to have the guaranteed service level.

BTS reserves minimum capacity for HSUPA based on commissioningparameters Minimum baseband decoding capability Mbps and Minimumnumber of HSUPA UE per BTS.

Minimum baseband decoding capability Mbps value is the sum of allHSUPA users' bit rates.

See the following tables for example CE utilisation figures of UltraSiteWCDMA BTS and Flexi WCDMA BTS HSUPA.

For example, BTS HSUPA traffic is expected to be at maximum of eightusers simultaneously and total HSUPA traffic to be up to 2.8 Mbps on L1.According to Table UltraSite WCDMA BTS and HSUPA CE utilisation, 48CEs are required for HSUPA.

Table 22. UltraSite WCDMA BTS and HSUPA CE utilisation

UltraSiteWCDMA BTS

Baseband decoding capability, Mbps L1

Number of HSUPAUE per BTS

0 <1.4 1.4 2.8 4.2 5.6

0 8 8 8 8 8 8

1-4 8 32 32 48 64 88

5-8 8 32 48 48 64 88

9-12 8 48 48 64 64 88

13-16 8 48 64 88 88 88

17-20 8 64 64 88 108 108

21-24 8 64 64 88 108 128



Table 23. Flexi WCDMA BTS and HSUPA CE utilisation

Flexi WCDMABTS

Baseband decoding capability, Mbps

Number of HSUPAUE per BTS

0 <1.4 1.4 2.8 4.2 5.6

0 8 8 8 8 8 8

1-4 8 32 32 56 80 112

5-8 8 32 56 56 80 112

9-12 8 56 56 80 80 112

13-16 8 56 80 112 112 112

17-20 8 80 80 112 136 136

21-24 8 80 80 112 136 160

For more information, see HSUPA in BTS.

7.5 Extended Cell

For more information on the Extended Cell feature, see RAN1127:Extended Cell (180km) in RAS06 Feature Descriptions.

Note that in RAS06, Extended Cell has been tested up to 100 km.

The basic principles for Extended Cell in WCDMA BTS are as follows:

. A cell is called Extended Cell when its radius is >20km.

. Cells with radius ≤ 20 km are treated according to normal basebanddimensioning rules.

. CE dimensioning needs to be calculated separately for eachExtended Cell. For example, if there is a 1+1+1 configuration, with 1* 20 km cell and 2 * 100 km cell, it is needed to calculate 1* 20 kmcell according to normal common channel dimensioning rules and 2* 100 km cells according to Extended Cell dimensioning rules.

. Extended Cell CE dimensioning rules are the same for all WCDMAfrequencies.

. One or several of the cells in the BTS (supported configurations) canbe configured as Extended Cells.

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Extended Cell and Flexi WCDMA BTS

Extended Cell common channel dimensioning rules for Flexi WCDMA BTSare as follows:

. Up to 60 km cell: 27 CE



Extended Cell and UltraSite WCDMA BTS

For UltraSite WCDMA BTS, it is advisable to have at least one WSPC perExtended cell (+WSP for normal CCCH) for optimal CE consumption.

Extended Cell common channel dimensioning rules for UltraSite WCDMABTS are as follows, provided that every Extended Cell has its own WSPC.(WSP capacity for normal CCCH):

. Up to 60 km cell: 16 UL / 16 DL CE

. Up to 120 km cell: 40 UL/ 16 DL CE

. Up to 180 km cell: 64 UL / 64 DL CE

7.6 BTS counters

Channel Element counters

The TCOM counts available and used capacity values using ChannelElements measure. Counters are reported to BTS Mgr and OMS viaBTSOM.

WBTS3.2 supported counters include maximum/minimum/averageavailable HW capacity and maximum/minimum/average used capacity forUL and DL.

New counters in WBTS4.0 include maximum/minimum/average usedcapacity for HSUPA.

For more information, see UltraSite WCDMA BTS and Flexi WCDMA BTSproduct documentation.



7.7 WCDMA BTS capacity allocation principles

7.7.1 UltraSite WCDMA BTS

This section provides an overview of managing the DSP andAsynchronous Transfer Mode (ATM) resources required for the commonand dedicated channels in the Wideband Code Division Multiple Access(WCDMA) Base Transceiver Station (BTS). In the WCDMA, the amount ofusers in the air interface can be relatively large, and therefore theallocation and efficient use of the resources are important. The reason forthis functionality is that the DSP processing and ATM transmissioncapacity have been distributed inside the BTS. The amount of mobileusers the BTS can carry depends on the services the users have. Forexample, a video call takes much more resources than a traditionalspeech call.

In the BTS, the Telecom (TCOM) software (SW) runs ResourceManagement(RM)-related tasks. In practice, the BTS TCOM RM SWreceives resource requests for different channel allocations from the RadioNetwork Controller (RNC). The BTS TCOM calculates the resource needfor the channel based on the parameters received in the resource requestand selects the appropriate resources for the requests. In case a WSP unitdoes not have enough resources, the call can be allocated to anotherWideband Signal Processor (WSP) unit under a specific WidebandApplication Manager (WAM) unit. Another important feature in the TCOMRM software is the load balancing between the BTS subracks and units.The BTS TCOM RM software has been divided into Global and LocalRMs.

Figure BTS TCOM RM overall presents the overall RM SW within the BTS.In brief, the Global RM takes care of the WAM and the Local RM of theWSP selection.

Figure 19. BTS TCOM RM overall

WSPs WSP WSP WSP WSP WSP WSP

On each WAM Local RM Local RM

Master WAM Global RM

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7.7.1.1 Primary/Secondary WAM

In the UltraSite WCDMA BTS, each subrack has two slots for the WAMunits, that is the Primary and Secondary slots, except for the MetroSite 50/WCDMA BTSs, which only have the Primary WAM slot available. The firstWAM in the subrack is always installed in the Primary unit slot which hasaccess to every control bus and can thus start and drive the subrack. TheSecondary WAM is required when there are more than three WSPsinstalled in a subrack. It provides ATM/ATM Adaptation Layer type 2(AAL2) capacity and telecom functions for the allocated WSPs. However, itdoes not have access to all control and data buses and cannot drive thesubrack in case of a Primary WAM failure.

Figure 20. Primary/Secondary WAMs in subrack

7.7.1.2 Master/Slave WAM

One of the Primary WAMs in a cabinet is the Master WAM. The WAM isthe master controller for the whole BTS and performs common O&M andtelecom functions such as operational software local storing anddistributing, configuration management, alarm collection, handling, andcabinet level telecom resource management. Other Primary WAMs, whichare not in a Master mode, are called Slave WAMs. A Slave WAM can beallocated to be a Master WAM in case of a current Master WAM failure. Anew Master WAM selection requires a BTS site reset.

R-busWAF

WTR

WAM

RR-bus

RT-bus

T-bus

WPA

WAF

WPA

WTR

WAM

WSP

WSP

WSP

WSP

WSP

WSP

DSC-bus

SecondaryWAM

PrimaryWAM

RR-bus

RT-bus

WSM



Figure 21. WSP and WAM allocation within a subrack

7.7.1.3 WSP and WAM allocation within a subrack

When a call setup procedure is started and a request is sent to the BTS,several decisions are required relating to resource allocations and theirmanagement. A basic guideline for a subrack/WAM selection is sharingthe load equally between the subracks and WAMs. This can be based onWSP load, ATM load, and AAL2 capacity. When a subrack/WAM (or theATM termination point) is selected, it cannot be changed. A call can bemoved within the WSPs under the selected WAM.

R-busWAF

WTR RR-bus

RT-bus

T-bus

WPA

WAF

WPA

WTR

DSC-bus

RR-bus

RT-bus

Secondary WAMs,always in Slave

WAM mode

Primary WAMs caneither be in Master orSlave WAM mode

R-busWAF

WTR RR-bus

RT-bus

T-bus

WPA

WAF

WPA

WTR

DSC-bus

RR-bus

RT-bus

R-busWAF

WTR RR-bus

RT-bus

T-bus

WPA

WAF

WPA

WTR

DSC-bus

RR-bus

RT-bus

IFU

WSC

AXU

lub

CarrierInterface

WSCMAIN

WSCREDU

WAM

WAM

WAM

WAM

WAM

WAM

ST-busSR-bus

ST-busSR-bus

ST-busSR-bus

ST-busSR-bus

WSM

WSM

WSM

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

WSP

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A WAM can handle up to three WSPs. The served WSPs are allocated toWAMS based on a unit slot number so that the lowest three WSP unitsfound are allocated to the Primary WAM and the last 1....3 units found forthe Secondary WAM. This kind of allocation is called a WAM pool, that isWAM + 1...3*WSP.

Example Four WSPs installed in bb-subrack slots 1, 3, 5, and 6, twoWAMs

Two WAM pools are created. The Primary WAM handles the WSPs in slots1, 3, and 5. The WSP in slot 6 is allocated to the Secondary WAM.

Figure 22. WSP to WAM allocation

7.7.1.4 Common Control Channel (CCCH) allocation

The following list summarises the different WSP units and their capacityalternatives in an Adaptive Multi-Rate speech codec (AMR)/CCCH mode.

WSPA:

. 32 AMR users, no common channels

. 24 AMR users, common channels for one cell

. 16 AMR users, common channels for two cells

. 8 AMR users, common channels for three cells

WSPC:

R-busWAF

WTR

WAM

RR-bus

RT-bus

T-bus

WPA

WAF

WPA

WTR

WAM

DSC-bus

SecondaryWAM

PrimaryWAM

RR-bus

RT-bus

WSM

WSP6

WSP5

WSP3

WSP1



. 64 AMR users, no common channels

. 48 AMR users, common channels for one - three cells

The CCCH allocation order is:

1. WSPA

2. WSPC

The CCCHs are allocated between the subracks to different WSP units forredundancy and load balancing reasons. The basic principles for a CCCHallocation are:

. Common connrol channels are primarily allocated to WSPA units ifavailable.

. Select a WAM that does not yet handle any common channels andhas a WSPA.

. If such a WAM is not found, select a WAM that handles the leastcommon channels and has a WSPA.

. If there is no WAM with a WSPA, select a WAM with a WSPC. Thesame WAM is also selected to handle the common channels of one -three cells.

When the CCCHs are allocated, they can be located in any subrack withina cabinet. In the following figures, the WSPAs are depicted as a four-DSP(RAKE-CODEC pair) environment having eight Channel Elements (CE) ineach. The WSPC is depicted as a one-DSP environment having 64 CEs.In the figures, one slot depicts one CE.

Example 1+1+1 configuration with two WSPA units in different subracks

The CCCHs are allocated so that subrack 1 has 2-cell CCCHs andsubrack 2 has 1-cell CCCH as shown in Figure Common control channelallocation example for 1+1+1 onfiguration with two WSPAs.

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Figure 23. Common control channel allocation example for 1+1+1configurationwith two WSPAs

Example 1+1+1 configuration with two WSPC units in differentsubracks

The CCCHs are allocated so that subrack 1 has all 3-cell CCCHs asshown in Figure Common control channel allocation example for 1+1+1configuration with two WSPCs.

Figure 24. Common control channel allocation example for 1+1+1 configurationwith two WSPCs

CCCH allocation with single WPA and several TRXs

A special case is when a WPA is divided between, for example, two TRXs.In this case, the CCCHs are allocated to WSPs which are allocated to thesame WAM unit due to WPA unit power control functions.

7.7.1.5 Dedicated Channel (DCH) allocation

Load sharing principles between WSP, WAM, and subrack

When a new Radio Access Bearer (RAB) service or a call setup isrequested, the following selections are done:

WSPA (1)

Subrack 1

WSPA (2)

Subrack 2

WSPC (1)

Subrack 1

WSPC (2)

Subrack 2



. Subrack/WAM selection, ATM termination

. WSP selection

. DSP environment selection

A basic rule for the subrack/WAM selection is sharing the load equallybetween the subracks and WAMs. Criteria for this are the WSP load, ATMload and AAL2 capacity. Based on a reference value calculated for eachWAM, the subrack and WAM which has the most unlimited capacityavailable are selected. With the WSP/DSP selection for a new RABrequest, the RRM primarily allocates the RAB to the most fully loadedWSP/DSP environment possible within the WAM pool WSPs. In otherwords, the RRM keeps a maximum number of resources free to enablehigh data rate calls. From RAN04 onwards, the RRM favours the WCPCunits for a new AMR call due to a possible reconfiguration or a new RABrequest, until the free capacity between the subracks or units is equal. Thefollowing table depicts the use of the CEs for different calls and data rates.

Table 24. The use of CEs with different data rate calls

User data raterequired

Number of CEs

#

AMR/16 kbit/s 1

PS 32 2

PS 64/128 4

PS 256 8

PS 384 16

CS 14.4 1

CS 57.7 4

CS 64 4

Example Load sharing principles between the WSP, WAM, and asubrack with 1+1+1 configuration with two WSPA units indifferent subracks

The CCCHs are allocated so that the subrack 1 gets 2-cell CCCHs andsubrack 2 gets 1-cell CCCH. The AMR calls 1...8 are allocated to subrack2 due to load balancing as presented in Figure CCCHs and eight AMRcalls in WSPA. The additional AMR calls are allocated one by one betweenthe subracks until the full capacity is used.

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Figure 25. CCCHs and eight AMR calls in WSPA

In case of higher data rate calls, the RRM checks the possibility to allocatea call to any existing eight-call environment if there are enough freeresources available. If not, the allocation is done to another subrack WSPAunit and a new eight-call environment is taken into use.

Example Load sharing principles between the WSP, WAM, and asubrack with 1+1+1 configuration with two WSPC units indifferent subracks

The CCCHs are allocated so that subrack 1 gets all the 3-cell CCCHs. TheAMR calls 1...16 are allocated to subrack 2. After that each new call isallocated one-by-one equally between the subracks as presented in FigureCCCHs and 16 AMR calls in WSPCs.

Figure 26. CCHCs and 16 AMR calls in WSPCs

In case of higher data rate calls which request more capacity, the followingnew AMR call is allocated to the other subrack due to load balancing.

Example Load sharing principles between the WSP, WAM, and a

WSPA (1)

Subrack 1

WSPA (2)

Subrack 2

WSPC (1)

Subrack 1

WSPC (2)

Subrack 2



subrack with 1+1+1 configuration with WSPA and WSPC unitsin different subracks

In case of a mixed WSPx configuration, all CCCHs are allocated to aWSPA unit, as presented in Figure CCCH allocation in mixed WSPA/Ccase. After that all resource requests are allocated to a WSPC until there isspace for eight AMR calls in both units, as presented in Figure Resourceallocation until equal amount of free resources.

Figure 27. CCCH allocation in mixed WSPA/C case

Figure 28. Resource allocation until equal amount of free resources

In Figure Resource allocation until equal amount of free resources above,the WSPC capacity is reserved for one 384 kbit/s, one 128 kbit/s, and two64 kbit/s PS data calls, and 28 AMR calls.

RAB reconfiguration

In case of a RAB reconfiguration, for exampl,e 64 kbit/s to 384 kbit/s, a callcan be re-allocated to another WSP unit under the same WAM pool,provided there are not enough free resources in the original WSP unit. Incase of lacking resources under the specific WAM pool WSPs, therequested RAB reconfiguration is rejected and the original 64 kbit/s serviceis maintained. In RAN1.5 with only the WSPA supported, the allocation is

WSPA (1)

Subrack 1

WSPC (2)

Subrack 2

WSPA (1)

Subrack 1

WSPC (2)

Subrack 2

Common channels

16 kbps or AMR

64 kbps

128 kbps

384 kbps

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done so that the fullest WSP unit (and in case of a WSPA also the fullest 8-call environment) that has enough capacity to handle the call is selected.From RAN04 onwards, WSPC is supported and the same principles applyas in RAN1.5.

MultiRAB support

In MultiRAB configurations, the RAB requests more resources than anAMR call. The principle is the same as in other cases, so that the totalRAB-requested resource amount is compared to the existing freeenvironment, and based on the load balancing principles, the mostunrestricted WAM environment is selected.

Asymmetric Uplink/Downlink (UL/DL) bit rate

Asymmetric UL/DL means that the UL and DL directions have different bitrate requirements. The rule for allocating resources for asymmetric bitrates is based on a higher data rate requirement. In practise, this meansthat the UL has some free resources reserved due to a higher DL bit rate.

7.7.1.6 Recovery actions

WSP failure

In case of a WSP failure with common channels, the cell is temporarily outof service while the CCCHs are re-allocated. If during the CCCH re-allocation no free resources are available, the cell stays down, and fromRAN04 onwards there will be an alarm related to that. In case of anallocated WSP failure for active calls, the calls are lost and must beredialled.

WAM failure

1. RAN1.5:

In case of a Slave or Secondary WAM failure, the specific WSPscontrolled by the failed WAM are lost, and the calls are dropped. Therecovery is through a site reset and the RF network is maintained,but with less WAM/WSP capacity. In case of a Master WAM failure,the recovery is not possible, and the whole BTS is down. The WAMmust be replaced to recover the situation. After an unwanted SlaveWAM reset, for example by power reset, the specific WTRs stay in adisabled state. The recovery is through a site reset.

2. RAN04:

In addition to RAN1.5, the Master WAM failure is the following:



The Master WAM is switched over to another Master WAM(=Primary WAM) candidate through a site reset. The failed MasterWAM and the associated Secondary WAM are lost, as is theassociate WSP capacity. Also the cell behind the Master WAM islost.

7.7.1.7 HSDPA

When a High-Speed Downlink Packet Access (HSDPA) call is established,there are needed capacity allocations or reservations on the VirtualChannel Connection (VCC), WAM, and WSP level. The VCC selection isdone by the RNC. Either a HSDPA Dedicated VCC or a Shared VCC isused. With BTS AAL2 multiplexing, the WAM and WSP selection are doneby the BTS. With Basic AAL2 multiplexing, the WAM selection is done bythe VCC selection.

For more information on the Shared VCC, see HSDPA Transport with BestEffort AAL2 QoS in RAN04 and RAS05 Transmission and TransportFeatures .

For more information on the Dedicated VCC, see RAN1020: Routeselection in RAS05.1 Transmission and Transport Features.

For more information on WAM allocation, see HSDPA functionality inHSDPA in BTS.

Example Shared VCC is used with BTS AAL2 multiplexing

1+1+1 BTS with 4*WSPC, 4*E1 Iub, Iub U-plane configured as 8000 cps +8000 cps Shared VCCs.

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Figure 29. BTS configuration example

The call allocation goes as:

CCH Allocation: The first WSPC is selected: WSPC1 and WAM1.

HSDPA allocation:

. "16 users BTS" and "16 users cell" the first HSDPA cell: the WAMwith the most free WSP capacity is selected (WAM3). WSPC3 isselected.

. "16 users cell" 2nd HSDPA cell: the WAM with the most free WSPCcapacity is selected (WAM1). The WSPC2 with the most free CEcapacity is selected.

. "16 users cell", 3rd HSDPA cell: the WAM with the most free WSPCcapacity is selected (WAM3). The WSPC with the most free CEcapacity is selected. (WSPC4).

Uplane8000cps

WAM1

WSPC1

WSPC2

Uplane8000cps

WAM3

WSPC3

WSPC4



Figure 30. HSDPA allocation example

Example The BTS is in operation, and there are several calls allocatedaround the WAMs and WSPs

The total traffic/BTS is 53*AMR, 6*64 kbps, 1*128 kbps, and 1*384 kbps.

WSPC1: 40 CE used, 24 free




WAM1: CCCH + 36 AMR + 5*64, 3375 cps

WAM3: 17 AMR + 1*128 + 1*384, 3473 cps

WSPC1

2nd HSDPA 1st HSDPA

WSPC2 WSPC3 WSPC4

WAM1 WAM3

Common channels

HSDPA

3rd HSDPACCCH

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Then a HSDPA call is established. The HSDPA is allocated to the WAMwhich has the most free WSP capacity: WAM3 with 87 free CEs isselected. Then the least loaded WSP, which has enough capacity for theHSDPA, that is the WSPC4 is selected. After that the load is:





WAM1: CCCH + 36 AMR + 5*64, 3375 cps

WAM3: 17 AMR + 1*128 + 384, 3473 cps

The associated DCH, that is 64 kbps, is allocated to the WAM1 and thereto the WSPC1.





WAM1: CCCH + 36 AMR + 6*64, 3591 cps

WAM3: 17 AMR + 1*128 + 1*384, 3473 cps

If another HSDPA cell is needed, it is allocated to the WAM3, as it still hasmore free CEs in the WSPCs (55 vs 52) and enough free CEs on theWSPC3 to allocate the HSDPA the 32 CEs needed. So after the secondHSDPA allocation, the WSP load is:







If the third HSDPA cell is needed, it is generated on the WSPC2, which isthe only WSPC with enough free CE capacity available and not yet havingHSDPA allocated.

Start:

Figure 31. BTS CCCH and DCH allocation example

The BTS load after the three HSDPA cells have been activated:

WSPC1 WSPC2 WSPC3 WSPC4

WAM1 WAM3

Common channels

HSDPA

CCCH

AMR or 8-16 kbps

64 kbps

128 kbps

384 kbps

WSPC1: 40 used, 24 free 53 * AMRWSPC2: 32 used, 32 free 6 * 64WSPC3: 28 used, 36 free 1 * 128WSPC4: 13 used, 51 free 1 * 384

WAM1: CCCH + 36 AMR + 5 * 64, 3375 cpsWAM2: 17 AMR + 1 * 128 + 1 * 384, 3473 cps

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Figure 32. BTS CCCH, DCH, and HSDPA allocation example

7.7.2 Flexi WCDMA BTS

Allocation of common control channels

The TCOM selects the least loaded System Module to handle the firstcell's CCCHs. The second and third cell's CCCHs are also allocated on thesame Submodule unit.

If there are more than three cells, the TCOM selects the another leastloaded Submodule unit to handle the fourth to sixth cell's CCCHs.

Allocation of dedicated channels

The RM of the TCOM allocates a new DCH user to the most loadedbaseband Submodule with sufficient capacity for that DCH. The TCOMtries to keep some baseband Submodule free as long as possible, so thatwhen a higher data rate request comes from the RNC, there are enoughresources for that.

The non-HSPA baseband Submodules are favoured for the DCH traffic.

For HSDPA, the baseband Submodule with the most free capacity isselected.

WSPC1

3rd HSDPA

2nd HSDPA

WSPC2 WSPC3 WSPC4

1st HSDPA

CCCH



8 Dimensioning RNC

Radio Network Controller (RNC) dimensioning is based on the RNCthroughput requirement in Mbps and Erlangs, the number of the BaseTransceiver Stations (BTSs) and cells to be connected with the RNC, andthe total sum of the ATM Adaptation Layer Type 2 (AAL2) connectivity forthe Iub, Iur, and Iu-CS interfaces. Therefore, RNC dimensioning requiresthat the preliminary dimensioning of the BTSs, Uu, Iub, Iur, and Iuinterfaces has been done, or is done in addition to RNC dimensioning.

For information on new capacity steps, see Nokia WCDMA RNC ProductDescription for RNC450 and Nokia WCDMA RNC Product Description forRNC196.

RNC connectivity calculation has been modified with the UBR+ feature.see RNC product descriptions for more information.

For RNC, RAS06 release is only a SW release since neither any changesin RNC configurations nor any new plug-in-units are introduced. Therefore,the configurations and capacity steps are as in RAS05.1 system release.

Due to the discontinuity of the support of the CCPC2-A, CDSP-B andMCPC2-A in RN3.0 release, all these old HW units must be upgraded intotheir new PIU variants. Capacity step 1 to 5 of RNC196 may currentlyinclude old HW. So, in all these five capacity steps of RNC196, the oldPIUs should be replaced at minimum as listed here:

. Replace CCPC2-A with CCP10 /CCP18-A

. Replace CDSP-B with CDSP-C

. Replace MCPC2-A with MCP18-B

Foe RNC configurations and capacity figures, see Nokia WCDMA RNCProduct Description for RNC450 and Nokia WCDMA RNC ProductDescription for RNC196.

RAN Capacity Planner can be utilised for RNC dimensioning.

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Dimensioning RNC

New HSPA rates on different layers (Air interface, RLC payload, FrameProtocol, ATM rate) are presented in the following table.

Table 25. HSPA rates

HSPA L1 rate (Uu),Mbps peruser

RLCpayloadrate, kbps

FP rate,Mbps

ATM rate,cps

HSDPA QPSK 1.8 1600 1.7 4710

HSDPA 16 QAM, 5codes

3.6 3360 3.6 9900


7.2 6720 6.9 19200


10 9600 9.9 27400

HSUPA 2 1888 2 5530

However, in RNC dimensioning, FP OH 1.1 for HSPA is used.

Iu-CS signalling link dimensioning figures are presented in the followingtable.

Table 26. Iu-CS signalling link dimensioning

Erlangs # links Needed BW(cps)

Link size(cps)

1000 2 2000 1000

3000 4 4000 1000

5000 6 6000 1000

7000 8 8000 1000

9000 10 10000 1000

11000 12 12000 1000



9 Dimensioning interfaces

9.1 Dimensioning Iub interface

RAS06 introduces several new features affecting Iub utilisation:

. RAN759: Path Selection

. RAN1099: Dynamic Scheduling for HSDPA with Path Selection

. RAN1100: Dynamic Scheduling for NRT DCH with Path Selection

. RAN1142: ATM over Ethernet for BTS

. RAN1063: Hybrid BTS Backhaul

. RAN1064: Ethernet+E1/T1/JT1 Interface Unit (Iub User Plane) forFlexi WCDMA BTS

. RAN1097: Ethernet Interface Unit IFUH (Iub User Plane) for AXC

. RAN1095: UBR+ for Iub User Plane

. RAN1096: Transport Bearer Tuning

For more information on these features, see RAS06 Feature Descriptions.

For a description of the Iub interface, see Iub interface in WCDMA RANInterfaces.

9.1.1 Transport Bearer Tuning

Transport Bearer Tuning (TBT) affects the Iub dimensioning; instead of100 % activity of PS DCHs, lower activity factors (AF) may be utilised. Theeffects can be investigated with the RAN Capacity Planner.

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Dimensioning interfaces

Activity Factor with Dynamic NRT DCH Scheduling

If AF is set to too low with TBT feature (384 kbps: AF < 0.5, for other rateAF< 0.6) the defaults (0,5 for 384 kbps and 0,6 for other speeds) are used.This limitation applies only to AFs for DL NRT bearers. This changing ofAFs is done only if the dynamic scheduling for NRT DCH with PathSelection feature is enabled for a BTS.

Activity Factors with Dynamic NRT DCH Scheduling with Path Selection

If the feature is enabled, an internal default value of AF=0.75 is used forNRT DCH DL and UL bearers. If the Transport Bearer Tuning feature(TBT) is enabled, the default value is not used. Instead, the operatorconfigurable AFs are used.

9.1.2 Hybrid transport

Hybrid transport solution enables BTSs to be backhauled over packet-switched technologies, IP and Ethernet in particular. Usage of Ethernetmay increase the delay over the Iub; however, current estimation is thatHSUPA can tolerate delays of up to 160 ms, after which the MacroDiversity Combining does not work properly. However, the estimated valueshould be verified.

For more information, see RAN1063: Hybrid BTS Backhaul in RAS06Feature Descriptions.

9.1.3 Iub VCC configuration

The Iub bandwidth is divided between:

. signalling links carried on AAL5 (Common Node B ApplicationProtocol (CNBAP), Dedicated Node B Application Protocol(DNBAP), Asynchronous Transfer Mode (ATM) Adaptation Layer 2Signalling (AAL2Sig))

. Operation and Maintenance (O&M) on AAL5

. User plane (U-plane) Virtual Channel Connections (VCCs) carriedon AAL2.

User plane VCCs also transport Common Control Channels (CCCHs),Dedicated Control Channels (DCCHs), and Dedicated Traffic Channels(DTCHs). Therefore, the capacity for Iub is as follows:

Iub capacity = U-Plane + CNBAP + DNBAP + AAL2sig + O&M



For the O&M, 150 cps (~64 kbps) is recommended per BTS.

The maximum number of the AAL2 connections per VCC is 248. TheCCCHs of one cell require 4-6 AAL2 connections, depending on theSecondary Common Control Physical Channel (S-CCPCH) usage. EachAdaptive Multirate (AMR)/Packet Switched (PS)/Circuit Switched (CS) callrequires 2 AAL2 connections (DTCH + DCCH).

The maximum size of AAL2 Path (AAL2UP VCC) in RAS05.1 RNC is41000 cps.

The Iub configuration principles are shown in Figure BTS AAL2multiplexing and Table Number of VCCs.

Note that in RAS05.1, the AXC ATM layer configuration management forBTS function makes the BTS internal VCC configuration between theWideband Application Manager (WAM)-ATM Cross-Connect Unit (AXU)automatic. Therefore, you do not see WAM-AXU commissioning at all;only Iub VCCs need to be commissioned.

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Figure 33. BTS AAL2 multiplexing

WAM2

WAM1

AXC(AXUA,AXUC,AXUD)

RNC

VC1-UPLANE (DCH)

VC2-AAL2 SIG

VC3-DNBAP

VC4-CNBAP

VC5-O&M

VC6-UPLANE (DCH)

VC7-AAL2 SIG

VC8-DNBAP

1 WSPC:64 CodeChannels

lub

WAM2

WAM1

RNC

lub

VC1-UPLANE (DCH)

VC2-AAL2 SIG

VC3-DNBAP

VC4-CNBAP

VC5-O&M

VC6-DNBAP

BTS with basic AAL2 multiplexing






AXC(AXUB,AXCC,AXCD)

BTSAAL2Multi-plexing

BTS with BTS AAL2 multiplexing

VC7-UPLANE (HSDPA)

VC9-UPLANE (HSDPA)

BTS internalVCCs configuredautomatically bythe RNS Split

feature



Note that the High-Speed Downlink Packet Access (HSDPA) andDedicated Channel (DCH) traffic can also share the same VCC.

Table 27. Number of VCCs

VCC BTS with basicAAL2 multiplexing

BTS with BTSAAL2multiplexing

Flexi WCDMABTS

ATMadaptationlayer

U-plane One per WAM (DCH)(*)

One per BTS(HSDPA) (**)

One per BTS (DCH)(*)

One per BTS(HSDPA)

One per BTS(DCH) (*)

One per BTS(HSDPA)

AAL2

CNBAP One per BTS One per BTS One per BTS AAL5

DNBAP One per WAM One per WAM One per BTS AAL5

AAL2sig One per WAM One per BTS One per BTS AAL5

O&M One per BTS One per BTS One per BTS AAL5

* One VCC can contain up to 248 AAL2 connections. In cases where theBTS capacity exceeds 248 AAL2 connections, more user plane VCCs perWAM or per BTS can be required.

** Used with the RAS05.1 Route Selection function. Alternatively, multipleVCCs can be configured for HSDPA .

9.1.4 Protocol overheads

The following protocol overheads are included in the Iub:

. Radio Link Control (RLC) (PS services): 5%

. Frame Protocol (FP): variable, depends on the data rate

. AAL2: 3 Bytes per AAL2 packet (payload max 45 Bytes) + 1 Byte/ATM cell

. ATM cell overhead: 10.4% = (53-48)/48

Note that partially filled ATM cells can be filled with padding that causesslight increase in the overhead.

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9.1.5 Connection Admission Control

The ATM Connection Admission Control (CAC) evaluates whether there isenough bandwidth for every new requested bearer. The ATM CAC IubAAL2 capacity requirement depends on, for example, the service mix,average and peak service data rate, Transmission Time Interval (TTI),allowed delays, and cell losses.

The accurate way for Iub dimensioning is to use Radio Access Network(RAN) Capacity Planner using the same AAL2 CAC algorithm as the RNC.The RAN configurations contain examples of the actual Iub capacities (seeIntroduction to Nokia RAN configurations).

The recommended parameters related to the RNC CAC algorithm are:

. Maximum packet loss on Iub/IuCS/Iur: 0.001 (10-3)

. Maximum allowed AAL2 queuing delay on Iub/IuCS/Iur: 10 ms

9.1.6 Iub signalling links

The Iub signalling links are CNBAP, DNBAP, and AAL2Sig carried onAAL5.

Note that the presented dimensioning recommendation is based on theNokia internal assumptions on traffic mixes. The traffic in operatingnetworks can have different characteristics causing different signallingloads. Note that it has been assumed that the used PS data rates are 64kbps or more; with the lower rates and 3GPP Iub, the DNBAP capacitymay need to be increased.

The main loading components of the CNBAP links are:

. Radio Link setup requests and responses

. Radio Resource Indication (RRI) messages

Therefore, the CNBAP bandwidth requirement depends on the call setupand radio link addition (soft handover) amounts, as well as the RRI period.

DNBAP transfers are, for example:

. Radio Link Measurement (RLM) Reports

. Radio Link Deletion commands



. Radio Link Re-configuration messages

. Radio Link branch addition commands (softer handovers)

Therefore, the DNBAP capacity requirement depends, for example, on thenumber of calls, call lengths, number of softer handovers, and RLM reportperiod.

AAL2sig is used for transmitting commands to set up and release AAL2connections inside user plane virtual channel connections.

Iub signalling link dimensioning recommendations

The Iub signalling amounts depend on the BTS configurations (cellamounts, RRI periods), subscriber amounts with related signalling asLocation Area/Routing Area (LA/RA) update procedures and registrations,and subscriber traffic amounts as the number of call setups, handovers,and so on.

During normal operation, the signalling link load should usually not exceed80%.

The estimated signalling bandwidth requirement for the Iub is that 6-7% ofthe Iub capacity has to be reserved for signalling. The signalling bandwidthdivision between the CNBAP, DNBAP, and AAL2Sig should be done in theratios of 1:2:1.

With multiple WAM sites, the DNBAP bandwidth is divided according to theWSP unit capacities configured behind each WAM.

Without advanced AAL2 multiplexing (AXUA) and multiple WAM sites, theAAL2sig bandwidth is divided according to the Wideband SignallingProcess (WSP) unit capacities configured behind each WAM.

The minimum link size for the CNBAP, DNBAP, and AAL2Sig is 39 cps.The maximum size is 2100 cps per WAM.

From the operating networks, the CNBAP load can be estimated by:

CNBAP Load [cps] = 3 + RL_Setups / s * RL_Setup_Resp_Msg_Size +RRI_Msg_Size/ RR_Ind_Period

where:

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. RL_Setups/s is the number of the Radio Link Setups per second.

. RL_Setup_Resp_Msg_Size is the size of the RL Setup Responsemessage in ATM cells. It can be estimated to be 2 ATM cells.

. RRI_Msg_Size is the Radio Resource Indication Message Size. Itcan be estimated to be 4 ATM cells for 1-3 WCDMA cells.

. RR_Ind_Period is the reporting period of the Radio ResourceIndication messages. The default value is 200 ms.

For the DNBAP, the required bandwidth depends on the number ofsimultaneous PS calls. Approximately 13 cps is needed for each PS call.Depending on the traffic mix, these values for DNBAP can exceed thevalues achieved by the basic 6-7% rule with 1:2:1 division.

Table 28. Bandwidth needed for DNBAP

Number of PS calls cps needed

20 260

40 520

60 760

80 1010

100 1260

9.1.7 Examples of Iub configurations

1+1+1 BTS, 2*WSPC, 1*WAM, 1*E1

Max. users/BTS 80

Num cells/BTS 3

Link capacities cps

CNBAP 78

DNBAP 150

AAL2Sig 78

Sum cps 306

Kbps 129.7 6.8% of Iub

The capacity of E1 is ~80 AMR calls.



1+1+1 BTS with BTS AAL2 multiplexing, 3*WSPC, 2*WAM, 2*E1

Max. users/BTS 160

Num cells/BTS 3

Link capacities cps

CNBAP 150

DNBAP 300

AAL2Sig 150

Sum cps 600

Kbps 254.4 6.9% of Iub

The capacity of 2*E1 is ~160 AMR calls.

The DNBAP has to be configured as 200+100 cps links.

9.1.8 Interface capacity

The following table presents the Iub physical interface types. Cell ratemeans the available VCC size of the interface expressed as ATM cells/second. With n*E1, n* VC-12, and n*JT1, the Inverse Multiplexing ATM(IMA) parameter has an effect on the transfer bit rates. The cell ratescorrespond to the default IMA parameter value 128.

Table 29. Iub interface types

Iub interface type Nominal bit rateMbit/s

Transfer Bit RateMbit/s

Cell rate cps

JT1, T1 1,544 1,536 3622

E1, ATM VC 2,048 1,920 4528

n*JT1, n*T1 n*1,544 n*1,487274 n*3592

n * E1 IMA, ATM VC n*2,048 n*1,904070 n*4490

STM1, ATM VC4, OC3 155,52 149,76 353207

STM1, ATM n*VC12 155,52 n*1,920 n*4528

STM1, ATM n*VC12IMA

155,52 n*1,904070 n* 4490

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9.1.9 BTS internal link configurations

In RAS05.1, the AXC ATM layer configuration management for BTSfunction makes the BTS internal VCC configuration between WAM-AXUautomatic. In other words, the BTS internal VCCs do not need to bedimensioned any more. Only Iub VCCs need to be commissioned.

9.2 HSDPA and Iub dimensioning

HSDPA protocol stack is presented in the following figure.

Figure 34. HSDPA protocol stack

The following overheads are present below the PDCP level:

. RLC: PDU size 320 bits payload + 16 bits header = 336 bits,overhead is 16/320 = 5%.

. Dedicated Medium Access Control (MAC-d): No header.

. FP: HS-DSCH data frame’s FP-header and tail produces nine bytesoverhead and each MAC-d Protocol Data Unit (PDU) produces onepadding byte overhead. There can be 1 – 34 PDUs in the HS-DSCHframe. Thus, the FP overhead varies between 3 – 19%. Forexample, for 10 PDUs in a frame the FP overhead is 9 + 10 = 19bytes = 152 bits, and 152 / 3360 = 4.5%. FP data rate = 100*3512 =351 kbps.

TCP

IP

NRT source

RNC

PDCP

RLC

MAC-d

FP

AAL2

ATM

FP

AAL2

ATM

MAC-hs

PHY

BTS

Destination

TCP

IP

PDCP

RLC

MAC-d

MAC-hs

PHY



Table 30. HSDPA Protocol overheads

RLC MAC FP rate (Iub)

Payload Mbps + RLC headersMbps

Payload + RLCheaders + FPMbps

RAS05 1.6 1.68 1.756

RAS05.1 3.36 3.53 3.65

The total Iub overhead requirements for HSDPA are 10% overhead fromRLC rate to FP rate, or 30% overhead from RLC rate to ATM rate.Additionally, 0-25% overhead is required on the Iub so that it does not limitthe rates and the full rates over the air interface can be achieved. Thisadditional overhead depends on whether high utilisation of the air interfaceor the Iub interface is preferred, as the simulation results in the followingtable indicate.

Table 31. HSDPA Iub overhead versus HSDPA RF capacity

Relative HSDPA capacitycompared to the maximal

85% 90% 95%

Additional Iub margin overaverage capacity

0% 15% 25%

For information on HSPA rates, see Table HSPA rates in DimensioningRNC.

9.3 Dimensioning Iur interface

Purpose

Iur is the interface between two RNCs. Iur carries traffic and signalling thatis generated when a mobile station is in soft handover state and attachedto two base stations that belong to different RNCs.

This procedure describes the dimensioning of the Iur interface, in otherwords, how to calculate the needed capacity for the interface.

For more information on Iur, see Iur interface in WCDMA RAN Interfaces.

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Before you start

Traffic calculations have been completed and thus the number of RNCs isknown. For RNC throughput based dimensioning, the Iur traffic has to beconsidered as part of Iub traffic.

For Iur dimensioning, check:

. number of RNCs

. RNC area border

. traffic between RNCs

Steps

1. Dimension the Iur interface.

The following figure explains the generic method for dimensioningthe Iur interface.

Figure 35. Iur dimensioning

Iur VCC size and amounts

Iurs per RNC

Total user traffic in the area

PS DataVoiceerlangs

Nokia assumption is thatIur traffic is 4-9 % of the Iu traffic.

From NW topology the numberof adjacent RNCs needs to beconsidered.

Iub traffic per RNC

Iur traffic per RNC

CS-dataerlangs

From the traffic model thesimultaneous traffic mixescan be determined.

When determining the VCC size themaximum bitrate for each serviceneed to be considered.



Iur traffic amounts between RNCs depend on the networkconfiguration and topology. Typically, Iur traffic amounts could be inthe range of 4 – 9 % of Iu traffic, but the actual values should bechecked according to the radio network plan.

The recommended way for Iur dimensioning is to use a minimum of1xE1 per E1 and, within this, a maximum of 4377 cps for user traffic(and the rest for signalling).

Expected outcome

The capacities of Iur connections have been calculated successfully.

9.4 Dimensioning Iu-CS interface

Purpose

The purpose of dimensioning the Iu-CS interface is to calculate the neededcapacity for the interface.

The Iu-CS is the interface between the RNC and the 3G MSC and/or 3GSGSN. For more information on the interface, see Iu-CS interface inWCDMA RAN Interfaces.

Before you start

Make sure that the traffic calculations have been completed and thenumber of the RNCs is known.

Check the following:

. RNC area (covered number of subscribers and mix of traffic classesand usage).

Based on the total CS side traffic and number of RNCs, the required Iu-CStraffic can be determined assuming that the Iu-CS side traffic is equallydivided between the RNCs. Therefore, the Iu-CS traffic can be calculatedas follows:

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Figure 36. Iu-CS dimensioning

The actual VCC sizes must be determined by using the Nokia RANCapacity Planner or by checking the recommended values for the certaincall mixes from the RAN configurations. For more information, seeIntroduction to Nokia RAN configurations in Configuring WCDMA RAN.

Example

As a simplified example, VCC with 9000 cps can support 248 AMR calls or49 CS 64 calls.

Steps

1. Calculate the total CS traffic in Erlangs in the RNC area.

2. Calculate the total CS traffic in Mbps in the RNC area.

3. Calculate the required transport network capacity for CS traffic.

Expected outcome

The number and capacities of Iu-CS links have been calculated.

Iu VCC size and amounts

User traffic per RNC

Total user traffic in the area

CS-dataerlangs

Voiceerlangs

User traffic per RNC- total traffic/amount of RNCs

Voice erlangs CS data erlangs- Assuming 12.2 AMR mode and- CS data divided into erlangs byeach service bit rates



9.5 Dimensioning Iu-PS interface

Purpose

The purpose of dimensioning the Iu-PS interface is to calculate thecapacity needed for it.

Iu-PS is the interface between the RNC and 3G MSC and/or 3G-SGSN.For more information, see Iu-PS interface in WCDMA RAN Interfaces.

For accurate dimensioning, perform Iu-PS dimensioning with the NetActTransmission Planner.

Before you start

The traffic calculations have been completed and the number of RNCs isknown.

Estimate the average size of the packet in order to calculate the amount ofoverhead.

For Iu-PS dimensioning, check:

. RNC area (covered number of subscribers and mix of traffic classesand usage).

Steps

1. Calculate the total PS traffic amount in Mbps from the RNC area.

2. Calculate the required Iu-PS bandwith in Mbps.

The amount of overhead depends on the length of the IP packet.The longer the packet is, the smaller the relative amount ofoverhead. You have to assume some packet length for dimensioningpurposes.

Nokia's recommendation is to use Unspecified Bit Rate (UBR) VCCsin Iu-PS side where a single VCC is created in each GPRSTunnelling Protocol-User Plane (GTPU). As the Iu-PS interface isimplemented by AAL5, it does not affect the user plane AAL2connectivity dimensioning.

Expected outcome

The capacity needed for the Iu-PS interface has been calculated.

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9.6 Dimensioning Iu-BC interface

Purpose

The purpose of dimensioning the Iu-BC interface is to calculate therequired capacity between the RNC and the Cell Broadcast Center (CBC).

For more information on the interface, see Iu-BC interface in WCDMARAN Interfaces.

Steps

1. Dimension the Iu-BC interface.

Iu-BC interface recommendation is 64 kbps for each Iu-BC linkbetween the CBC and the RNC.

9.7 Iu and Iur MTP3 links

The current dimensioning rules recommend that the Iu Radio AccessNetwork Application Part (RANAP) signalling is 6% of the user planes.This can be used as a guideline and a dimensioning rule, but to simplifythe rules, the following guidelines are recommended in RAS06:

Table 32. Iu-CS MTP3 dimensioning

Erlangs Number of links Needed BW(cps)

Link size (cps)

1000 2 2000 1000

3000 4 4000 1000

5000 6 6000 1000

7000 8 8000 1000

9000 10 10000 1000

11000 12 12000 1000



Table 33. Iu-PS MTP3 dimensioning

User plane BW Number of links Needed BW Iu-PS

# (CPS) link size (CPS)

85 2 2000 1000

122 4 4000 1000

159 6 6000 1000

196 8 8000 1000

300 14 14000 1000

450 16 20000 1300

For the Iur interface, the recommendation is 64 kbit/s, that is, 150 cps linkfor each Iur connection between two RNCs.

For instructions, see:

. Dimensioning Iub interface

. Dimensioning Iu-CS interface

. Dimensioning Iu-PS interface

. Dimensioning Iur interface

. Dimensioning Iu-BC interface

See also Iur interface in WCDMA RAN Interfaces.

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dimensioning wcdma ran

Mobile

dimensioning bts

dimensioning wcdma

hsdpa capacity dimensioning

hsupa capacity dimensioning

dimensioning rnc

dimensioning interfaces

dimensioning steps

dimensioning flexi wcdma