154680772 09 pcu and pcu2 capacity and dimensioning v1 2

1 © 2007 Nokia PCU and PCU2 Capacity and Dimensioning / 13-jul-2007/EmBe

PCU and PCU2

Capacity and

Dimensioning


Legal Notice

Intellectual Property Rights

• All copyrights and intellectual property rights for Nokia training documentation, product documentation and slide presentation material, all of which are forthwith known as Nokia training material, are the exclusive property of Nokia. Nokia owns the rights to copying, modification, translation, adaptation or derivatives including any improvements or developments. Nokia has the sole right to copy, distribute, amend, modify, develop, license, sublicense, sell, transfer and assign the Nokia training material.

• Individuals can use the Nokia training material for their own personal self-development only, those same individuals cannot subsequently pass on that same Intellectual Property to others without the prior written agreement of Nokia.

• The Nokia training material cannot be used outside of an agreed Nokia training session for development of groups without the prior written agreement of Nokia.


Module Objectives

• After completing the module, the student will be able to:• Understand of PCU and PCU2 functionalities in the BSC

• Know Nokia option for PCU and PCU2 location in the BSC

• Distinguish the PCU and PCU2 limiting factors

• Know the BSCs limiting factors

• Understand main PCU/BSC Dimensioning rules and how to use them

• Practical exercise of PCU and PCU2 Dimensioning


GPRS networkPCU

functionalityBSC Location


PCU Functionality

GPRS transmission plane protocol stack

PCU functionality


PCU functionality

• PCU main functionalities are:• GPRS Radio Resource Allocation and Management

• GPRS Radio Connection Establishment and Management

• Data Transfer (LLC Layer PDU segmentation / re-segmentation for UL & DL)

• Coding Scheme Selection

• PCU Statistics

• PCU covers RLC/MAC functionality towards the Abis interface and BSSGP and NS towards Gb


CCU and PCU Position

• CCU (Channel Coding Unit) is in the BTS and PCU (Packet Control Unit) is implemented at the BSC site

• The information between PCU and CCU is transferred in frames with fixed length of 320 bits (PCU Frames)

• PCU Frames are an extension of the TRAU Frames and are therefore transmitted at 16kbps instead of traffic over Abis interface


BSC/ PCU Connectivity

• Every PCU is connected to the GSW with two different PCMs for Abis and 2 redundant PCMs for Gb over Frame Relay

• PCU is also connected to the Ethernet Switches with two LAN connectors

• The physical position of the PCU is inside the BCSU cartridge


PCU2 = 2nd Generation Packet Control Unit

• PCU2 provides a means to control (E)GPRS radio resources • Radio resource allocation and management

• Connection establishment and management

• Scheduling

• Data transfer, LLC PDU handling

• Coding scheme selection

• Gb load sharing (uplink) and flow control (downlink)

• MS uplink Power Control

• Initial timing advance (uplink, downlink)

• PCU status info collection - statistics


PCU2 Interfaces

PCUSIG PCI/DMC

(internal interface)

Abis

PCU2

Gb overFrame Relay or

IPv4/IPv6

Service Terminal

SGSN

MCMUBCSU

BSC

PCU2 transmits and receives TRAU frames to

and from the Base Stations

PCU2 transmits and receives Frame Relay

packets or IP packets to and from the SGSN

PCU2 can be connected to max. 256 x 16 Kbit/s Abis channels, in 256 TRXs in 128 BTSs in 64

Cells/Segments.


Nokia PCU Product Family

Second generation PCU for BSC3i, includes two logical PCUs

PCU2-D

Second generation PCU for BSCE, BSC2E/A, BSCi and BSC2i

PCU2-UNokia Second Generation Packet Control Unit - PCU2

First generation PCU for BSC3i, includes two logical PCUs

PCU-B

First generation PCU for BSCE, BSC2E/A, BSCi and BSC2i

PCU-T


PCU-S


PCUNokia First Generation Packet Control Unit - PCU1

Explanation Name of HW product variant

General name

Packet Control Unit, a general term for all Nokia GSM/EDGE PCU versions

PCU


Internal Restrictions

Internal PCU1 restrictions

• 16 DSP per logical PCU

• one DSP core can handle only one EDAP but one EDAP can be shared by several DSP cores.

• In the PCU1s, one DSP core can handle 0 to 20 channels (16 kbit/s), therefore max 256 per PCU1.

• PCU1 and PCU1-S can handle 128 radio timeslots or 256 EDAP channels.

• PCU1 does not support CS–3 & CS–4, Extended Dynamic Allocation (EDA), High Multislot Classes (HMC) or Dual Transfer Mode (DTM).

Internal PCU2 restrictions• 8 DSP per logical PCU but more

powerful• one DSP core can connect two

EGPRS dynamic Abis pools (EDAP), but one EDAP can be shared by several DSP cores.

• One DSP core handles 40 channels. The maximum number of 16 kbit/s channels per PCU2 is 256.

• PCU2 does not support PBCCH/PCCCH.

• PCU2 does not support GPRS with Nokia InSite BTS.


PCU2 HW Installation in BSC3i 1000 / 2000

• Max 10 working BSCUs + 1 spare BCSU

• Max 5 PCU plug-in units per BCSU (10 logical PCUs per BCSU)

• 1-2 PCU-B’s• 1-5 PCU2-D’s

• Max number of logical PCUs : 100

• Steps of increase of logical PCUs

• 1: 20 • 2: 40 • 3: 60 • 4: 80 • 5: 100

1-5 PCU2-D physical PIU's per

BCSU

1-2 PCU-B physical PIU's

per BCSU


PCU2 HW Installation in BSC3i 660

PCU2-DInstallation for

PCU slot(s)in every BCSU

unit

Product evolution with Product evolution with new Nokia PCU2new Nokia PCU2

• PCU2-D can be installed to every BCSU unit according to N+1 redundancy principle

• PCU2-D unit can also be used as extension PCU to 2nd PCU slot

• capacity extensions according to PS traffic needs


Smooth upgrade to Smooth upgrade to existing Nokia BSCsexisting Nokia BSCs

• PCU2-U unit can be installed as 1st or 2nd PCU in existing BSC2i products

• for 2nd PCU GSWB extension kit is needed if not already implemented

• Optional extra ET5C Cartridges

can be installed also if additionalE1/T1 connectivity is needed

• increase PCMs in BSC2 from 112 to 144 E1/T1

• New PCU technology ensures long term BSC2i investment protectionas well as evolution to future services

4th SW64B Plug in Unit4th SW64B Plug in Unit

ET5C extension cartridgesif additional

PCM connectivity

needed

ET5C extension cartridgesif additional

PCM connectivity

needed

PCU2-UInstallation for

2nd PCU slotin every BCSU

unit

PCU2-UInstallation for

2nd PCU slotin every BCSU

unit

PCU2 HW Installation in BSC2i


BSC Application software require PCU2

• S11.5 Application features:• GPRS CS3&4

• S12 Application features:• High Multislot Classes for Type 1 MS

(HMC)

• Extended Dynamic Slot Allocation (EDA)

• Dual Transfer Mode (DTM)

• (E)GPRS inactivity alarm


Gb dimensioning

• Several options are available to connect PCU to PS Core Network

• These are the frame relay options

• Another way not shown here is to connect Gb over IP using Ethernet Switches and Routers

• Capacity of Gb over IP is always 2Mbps per logical PCU


How many PCUs do we need?

• Given the PCU capabilities and the radio network capacity requirements, we can find out L, logical PCUs needed

• PCU Utilization = 75%

• Physical = Logical / 2 in BSC3i*

Limits per PCU PCU1PCU-

BPCU2-

UPCU2-

D

Max RTSLs * 128 256 256 256

Max 16kbps Abis Ch 256 256 256 256

Max EDAPs per PCU 16 16 16 16

Max BTSs 64 64 128 128

Max SEGs 64 64 64 64

Max TRXs 128 128 256 256

Max 64kbps Gb Ch 32 32 32 32

Logical PCU per PIU 1 2 1 2

Max PCU PIU per BCSU 2 2 2 5

S10.5 and S11 limitationsPCU2 not supported

PCU1 Max RTSLs = 256


Exercise

• Assume that a network is having 1 BSC

• There are 8 PCU cards in the BSC

• Default + Dedicated territory = 3

• There are 3 sectors/site

What is the maximum number of BTS that can be handled by the BSC?

• Consider EDAP size to be 8 Timeslots


Conclusions

Now you are able to: • Understand of PCU and PCU2 functionalities in the BSC

• Know Nokia option for PCU and PCU2 location in the BSC

• Distinguish the PCU and PCU2 limiting factors

• Know the BSCs limiting factors

• Understand main PCU/BSC Dimensioning rules and how to use them

• Practical exercise of PCU and PCU2 Dimensioning


Thank You

154680772 09 pcu and pcu2 capacity and dimensioning v1 2

Documents

nokia training material

nokia training documentation

exclusive property of

pcu packet control unit

thempractical exercise

agreed nokia training

bits pcu framespcu frames

bscknow nokia option