Wimax Radio Network Planning V0.2
- 1. WiMAX Radio Network Planning BP Tiwari email: [email protected] 1 beyond4g.org
- 2. 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 2 Beyond4G.org
- 3. 1 Balance of Coverage and Capacity Network planning Planning Strategy BALANCE •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 3 Beyond4G.org
- 4. 2 Set Designing Rules Applications : Enterprise or Retail Coverage Factor like QoS , Concurrency and peak Planning hour usage/Average Strategies Calculate Average user data rate for Retail/Enterprise 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 4 Beyond4G.org
- 5. 2 WiMAX Frequency Plan Coverage 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 5 edge overlap Beyond4G.org
- 6. 2 Reuse 1 vs Reuse 3 Coverage Planning PAP Strategies Reuse 1 Reuse 3 Parameter Reuse 1 Reuse 3 Comment Spectral 1.3 2.24 Efficiency % Spectral 100 66.8 Reuse 1 is Efficiency gain more efficient with respect to reuse 1 Coverage 0.27 0.35 Reuse 1 lower (DU) coverage 6 Beyond4G.org
- 7. 2 WiMAX Link Budget Coverage Link Budget Analysis Planning PAP Max Allowable Path Loss Strategies 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 7 Margin Beyond4G.org
- 8. 2 DL System Gain (1/1) Coverage 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 8 Beyond4G.org
- 9. 2 DL System Gain (1/2) Coverage Planning Strategies 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 9 Beyond4G.org
- 10. 2 DL System Gain (1/3) Coverage Planning Strategies 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 10 Beyond4G.org
- 11. 2 UL System Gain (1/1) Coverage 48 Kbps per Sub Planning channel Strategies 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 11 Beyond4G.org
- 12. 2 UL System Gain (1/2) Coverage CPE or outdoor Planning device will have higher gains Strategies 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 antennas With 2Tx can provide additional combing gains. 12 Beyond4G.org
- 13. 2 UL System Gain (1/3) Coverage Planning Strategies 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 13 Beyond4G.org
- 14. 2 Building Penetration losses Coverage Planning Strategies 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. 14 Beyond4G.org
- 15. 2 System Margins Coverage Planning Strategies 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 15 Beyond4G.org
- 16. 2 Cell Radius Coverage Link END Planning MAP Budget L PREDICTI TARGETS CELL Strategies ONS in gRADIUS CW l Tun Mode Optimization 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 . 16 Beyond4G.org
- 17. 2 Prediction Plots Coverage END Planning Strategies Example Prediction plot Production plots for UL,DL RSSI, CINR , Preamble, Best Bearer , throughput etc Final Site Count etc Site acquisitions based on prediction plots 17 Beyond4G.org
- 18. 3 Capacity Capacity END Planning Strategies Example Area to understand Capacity Planning Capacity Planning Inputs – Subscriber Projections – Data Rate Requirement Parameter Year 1 Year 2 Yea3 DU 45000 90000 140000 UR 15000 30000 60000 SU 3000 5000 8000 Data Rate 64 kbps 96 kbps 128 kbps 18 Beyond4G.org
- 19. 3 Capacity Capacity END Planning Parameter BTS DU BTS DU BTS UR BTS UR Capacity Coverage Capacity Coverage Strategies Year 1 96 222 32 142 Year 2 288 222 96 142 Year 3 597 222 240 142 Example Area to understand Capacity Planning 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 19 Beyond4G.org
- 20. 3 In Building Solution Capacity •PICO/Femto END •Pole or Wall Mount out Installation Planning •Typically 200mw to 1 Watts Strategies •Covers 30 to 70 Meters •Average Capacity : 10 Mbps DL •Average Capacity : 3-4 Mbps UL •Power : 100 /45 Watts From/To ANS-GW •DC or AC •Omni or Sector or DAS 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 20 Beyond4G.org
- 21. Thanks Feel free to email any clarification or additional inputs at [email protected] Join Discussion Forum at www.beyond4g.org/4gforum to exchange information and discuss aspects of 4G Technologies . 21 Beyond4G.org