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1 beyond4g.org beyond4g.org
WiMAX Radio Network Planning BP Tiwariemail: admin@beyond4g.org
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
3 Beyond4G.orgBeyond4G.org
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
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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
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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
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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
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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
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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
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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
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2Coverage Planning Strategies
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
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2Coverage Planning Strategies
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
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2Coverage Planning Strategies
UL System Gain (1/2)
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
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2Coverage Planning Strategies
UL System Gain (1/3)
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
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2Coverage Planning Strategies
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.
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2Coverage Planning Strategies
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
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2Coverage Planning Strategies
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
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2Coverage Planning Strategies
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
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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
19 Beyond4G.orgBeyond4G.org
3Capacity Planning Strategies
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
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3Capacity Planning Strategies
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
21 Beyond4G.orgBeyond4G.org
Thanks
Feel free to email any clarification or additional inputs at admin@beyond4g.org Join Discussion Forum at www.beyond4g.org/4gforum to exchange information and discuss aspects of 4G Technologies .
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