2. All rights reserved © 2001, Alcatel — 2 Higher Order Modulation in LMDS Networks Higher Order Modulation in LMDS Networks BBWWF - San Francisco, February 2001 Joe Fournier

3. All rights reserved © 2001, Alcatel — 3 Higher Order Modulation in LMDS Networks Agenda t Why the consideration of modulation? t Frequency Planning t Interference Prone Zones t Cell Radius t Dynamic or Static Multi Modulation Networks t Summary

4. All rights reserved © 2001, Alcatel — 4 Higher Order Modulation in LMDS Networks Why The Consideration of Modulation? t An Operator may require greater channel capacity which can be achieved by larger carriers and/or higher order modulation than QPSK or both t... and have the need for greater network capacity t Many ways of achieving this including larger spectral license, cell splitting, micro-cell insertion, increased #sectors/cell, t.... And higher order modulation (16-QAM, 64-QAM) t The key is to limit the impact on the network when using higher order modulation due to t reduced frequency reuse t non serviceable areas due to interference t smaller cell radius

5. All rights reserved © 2001, Alcatel — 5 Higher Order Modulation in LMDS Networks Impact of Modulation on...Frequency Planning t Frequency re-use determines C/I levels in network t 16 and 64 QAM require better noise performance (C/N) than QPSK. (12dB for QPSK vs. 19dB for 16 QAM and 25dB for 64 QAM) t This makes 16 and 64 QAM more sensitive to interference. t In a real world LMDS multi-cell network, this greatly impacts frequency reuse and therefore overall spectral efficiency.

6. All rights reserved © 2001, Alcatel — 6 Higher Order Modulation in LMDS Networks Frequency Planning 14 dB 19 dB 22 dB Victim (blue) is interfered with by many interferers along radials

7. All rights reserved © 2001, Alcatel — 7 Higher Order Modulation in LMDS Networks Frequency Planning 14 dB 19 dB 22 dB 14 dB C/I achieved

8. All rights reserved © 2001, Alcatel — 8 Higher Order Modulation in LMDS Networks Frequency Planning 14 dB 19 dB 22 dB Analogous for the remaining 3 types of sectors: 14 dB C/I achieved (specific freq. used in yellow sectors)

9. All rights reserved © 2001, Alcatel — 9 Higher Order Modulation in LMDS Networks Frequency Planning 14 dB 19 dB 22 dB 4 frequencies to cover all cells: 14 dB C/I achieved

10. All rights reserved © 2001, Alcatel — 10 Higher Order Modulation in LMDS Networks Frequency Planning 14 dB 19 dB 22 dB 16 frequencies to cover all cells: 19 dB C/I achieved

11. All rights reserved © 2001, Alcatel — 11 Higher Order Modulation in LMDS Networks Single Modulation Networks t Minimum of 4 and 16 frequencies for 4 and 16-QAM respectively (no cross-polarization assumed) t If more frequencies are available, these can be used in every sector resulting in the following re-uses: t 4-QAM re-use = (N-3)/N *100% (where N=total # of freq’s) t 16-QAM re-use = (N-15)/N *100% t Example (Total spectrum of 30 frequencies) t 4-QAM re-use = (30-3)/30 *100% = 90% t 16-QAM re-use = (30-15)/30 *100% = 50%

12. All rights reserved © 2001, Alcatel — 12 Higher Order Modulation in LMDS Networks...So the solution is a combination of both t Modulation Co-existence ~100% radio coverage <100% frequency reuse i.e. 90% QPSK only 50% 16QAM only Interference prone zone Non cc interference prone zone ~100% radio coverage (80%16QAM & 20%QPSK *)... But QPSK frequency reuse QAM16 QPSK only * multi-cell network

13. All rights reserved © 2001, Alcatel — 13 Higher Order Modulation in LMDS Networks Interference Prone Zones t Interference prone slivers contours depend on requires C/I and re- use and TS antenna pattern t The frequencies in the slivers must follow the re-use scheme shown earlier. Outside slivers, any frequency can be used Victim Interferer Interference sliver

14. All rights reserved © 2001, Alcatel — 14 Higher Order Modulation in LMDS Networks Interference Prone Zones 16-QAM sliver 4-QAM sliver t Interference prone slivers contours are larger for 16-QAM than for 4-QAM

15. All rights reserved © 2001, Alcatel — 15 Higher Order Modulation in LMDS Networks Cell Radius t Typical cell radii for single modulation networks 1 : t QPSK : 3000m t 16-QAM: 2100m 1 Rain region K, ITU-R rain model, multi-carrier

16. All rights reserved © 2001, Alcatel — 16 Higher Order Modulation in LMDS Networks Multi Modulation Static Networks 16QAM t Static multi modulation network (single cell shown) QPSK Clear Sky Rain QPSK QAM16

17. All rights reserved © 2001, Alcatel — 17 Higher Order Modulation in LMDS Networks Static or Dynamic Modulation t Multi Modulation Static or Dynamic Networks t Several levels of modulations used in every sector t Can be assigned to each user either statically or dynamically based upon channel conditions t Cell radius determined by lowest order modulation used and additional back-off if required

18. All rights reserved © 2001, Alcatel — 18 Higher Order Modulation in LMDS Networks Multi Modulation Dynamic Networks 16-QAM t Dynamic multi modulation network (single cell shown) 4-QAM Clear Sky Rain QPSK QAM16

19. All rights reserved © 2001, Alcatel — 19 Higher Order Modulation in LMDS Networks Multi Modulation Static or Dynamic Networks t Design networks for 4-QAM t Static networks: pre-assign modulation to users. Use same modulation for clear sky and rain conditions t Typical ratios of users allocated to 4-QAM and 16-QAM 1 : t Clear or Rain: 4-QAM ~ 15-20%, 16-QAM ~ 80-85% t Dynamic networks: dynamically assign modulation to users based upon channel conditions...gain due to cell radius t Typical ratios of users allocated to 4-QAM and 16-QAM 1 : t Clear sky: 4-QAM ~ 5-10%, 16-QAM ~ 90-95% t Rain: 4-QAM ~ 15-20%, 16-QAM ~ 80-85% 1 Numbers based upon certain assumptions and are not guaranteed

20. All rights reserved © 2001, Alcatel — 20 Higher Order Modulation in LMDS Networks Summary t Higher order modulation increases channel efficiency and can increase network capacity t Design networks for QPSK and use modulation co- existence t Consider larger interference prone zones where higher order modulation coexistence is present t Consider a smaller cell radius for the static higher order modulation users t With dynamic modulation, negate the impact on cell radius during clear sky conditions t Whatever the case, every method is strictly a template used as the starting point for actual detailed planning using RNP tools