wimax radio network planning v0.2

1 beyond4g.org beyond4g.org

WiMAX Radio Network Planning BP Tiwariemail: [email protected]

2 Beyond4G.orgBeyond4G.org

Presentation Outline

Understanding Coverage and Capacity Coverage Planning Strategies

– Designing Rules – Link Budget considerations – Cell Radius – Prediction plots

Capacity Planning Strategies –Design Rules and guidelines –Approaches for capacity planning


Balance of Coverage and Capacity1

•Getting balance in the key for effective Radio network planning• Coverage meeting business Requirement • Capacity to support user demands• Network quality for high customer satisfaction • Improve ROI

Planning Strategy

Network planning

BALANCE


Set Designing Rules 2Coverage Planning Strategies

Applications : Enterprise or Retail

Calculate Average user data rate for Retail/Enterprise

Factor like QoS , Concurrency and peakhour usage/Average

Input for Average sector and cell edge user data Rate

Data Rates : User, Sector and Cell Edge Device types : USB/PCMCIA , Indoor or Outdoor Coverage Boundary Frequency Resource Available


WiMAX Frequency Plan2Coverage Planning Strategies

Reuse 1 Reuse 3

Reuse 1 –All sectors use same frequency –Interference areas in sector and cell edge overlap

Reuse 3–Each sector use different frequency channel

between adjacent sectors –Low interference in adjacent sectors and cell

edge overlap


Reuse 1 vs Reuse 3 2

PAP

Coverage Planning Strategies

Reuse 3 Reuse 1

Reuse 1 lower coverage

0.350.27 Coverage (DU)

Reuse 1 is more efficient

66.8100% Spectral Efficiency gain with respect to reuse 1

2.241.3Spectral Efficiency

CommentReuse 3 Reuse 1 Parameter


WiMAX Link Budget 2

PAP

Coverage Planning Strategies

Link Budget Analysis

Max Allowable Path Loss

Estimate Cell Radius By Tuned Propagation Model

Estimate Cell Count

Link budget allows calculation of maximum allowed path loss (MAPL) of wireless signal MAPL( Max Allowed Path Loss)= System Gain - Total Margin; System Gain = EIRP – Min Signal Strength Required

– ERIP=Max Tx Power + DL Antenna Gain+ Pilot power Boosting Gain- DL cable loss;

– MSSR=RX Sensitivity Composite-UL Antenna Gain+ UL cable Loss ;

Total Margin=Indoor Loss +Slow Fading Margin+ Interference Margin


DL System Gain (1/1) 2Coverage Planning Strategies

PB3 for pedestrian or VA30/60 for mobile PUSC or AMC depending on Network Req. Frequency reuse3 for higher coverage MCS of QPSK ½ for data can provide 3.82 mbps

without MIMO and Rep 4 can provide ~.900 mbps. MAP Repetition 4 to balance Hw link budget , 7 db

additional gain


2Coverage Planning Strategies

DL System Gain (1/2)

3-6 db combining gain depends on number of TRX 1 dB gain for CDD with 2 antennas and 3 dB gain

for CDD with 4 antennas (only for MAP) TTA (Tower Top Amplifier), RRH (Remote Radio

Head) Adjust cable loss in case of no TTA/RRH



DL System Gain (1/3)

CINR required includes fading margin , 8-9 db for QPSK1/2 Data and 6-7 db for MAP Map ¼ Repetition gain of 4 db Required RSSI for demodulate QPSK1/2 is -95

dbm Example downlink system gain is 150.4



UL System Gain (1/1)

To support 128 kbps 3 sub channels are required Total sub channels are 35 in uplink Lower cell edge data rate can be used for planning

but today minimum sub channel is limited by SBC-Req Message

48 Kbps per Sub channel




Maximum power is dependent on device types for ex. USB is ~23 dbm and Indoor CPE is 27 dbm. Antenna gain will vary according to Device types

for ex. Indoor CPE has ~5-7 db gain antennasWith 2Tx can provide additional combing gains.

CPE or outdoor device will have

higher gains




Rx Noise figure is Base Station dependent Cable loss can be reduced using TTAs Required CINR for QPSK ½ 128 kbps is 4.7 Implementation margins of 1-2 db HARQ gains in the range of 3-4 db Example link budget is 147.7 db



Building Penetration losses

Stone and Brick walls amount for highest penetration loss Unlike Voice , WiMAX is mostly planned for first

wall. Every additional db can increase 10% Base Station.



System Margins

MAPL = System Gains – System Margins Minimum of Example system gains in DL/UL is

147.7 Total Margins are : 24.4 MAPL = 147.7 – 25.4 Ex. MAPL available 122.0



Cell Radius

Using a standard model like Cost 231 Hata Cell radius can be calculated – Ex. Cell radius in DU is 240 Meters

After Cell Radius using a RF planning tool prediction plots are generated .

CELL RADIUS

Link Budget

Model Tuning

MAPL

CW

PREDICTIONS

TARGETS

Optimization

END



Prediction Plots

Production plots for UL,DL RSSI, CINR , Preamble, Best Bearer , throughput etc Final Site Count etc Site acquisitions based on prediction plots

END

Example Prediction plot


3Capacity Planning Strategies

Capacity

Capacity Planning Inputs – Subscriber Projections – Data Rate Requirement

END

Example Area to understand Capacity Planning

1400009000045000DU

600003000015000UR

128 kbps96 kbps64 kbps Data Rate

SU

Parameter

800050003000

Yea3 Year 2Year 1



Capacity

Key findings

– Different approaches for different clutters – We have seen in our analysis that Dense clutter will require

additional cell site to cater the capacity requirement – Operator may choose to add more carriers provided has

enough spectrum or;– Choose to install additional Base Station – Or offload capacity thorough In building solution

END

Example Area to understand Capacity Planning 240

96

32

BTS UR Capacity

597

288

96

BTS DU Capacity

142222Year 2

142222Year 3

Year 1

Parameter

142222

BTS UR Coverage

BTS DU Coverage



In Building Solution

Operator may choose to increase Capacity through Pico or Femto Base Station Suitable for Corporate and Residential complexes Small Base station creating more capacity Improves in building coverage

END•PICO/Femto

•Pole or Wall Mount out Installation

•Typically 200mw to 1 Watts

•Covers 30 to 70 Meters

•Average Capacity : 10 Mbps DL

•Average Capacity : 3-4 Mbps UL

•Power : 100 /45 Watts

•DC or AC

•Omni or Sector or DAS

Ethernet

From/To ANS-GW

GPS


Thanks

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wimax radio network planning v0.2

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