1. 802.22 Coexistence Aspects Author: January 2006
doc.: IEEE /0006r0
Coexistence Aspects
Author:
Abstract
This contribution summarizes graphically the coexistence features developed in the Draft Standard.
Notice: This document has been prepared to assist IEEE It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.
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Gerald Chouinard, CRC
Gerald Chouinard, CRC

2. Outline Summary of 802.22 characteristics
Interference issues between long range and short range systems
Detection distance and interference distance
Detection threshold levels to coexist with
coexistence tools available to
Coexistence techniques in
Spectrum etiquette
On-channel re-use
on-channel coexistence TDMA capabilities
Terrestrial geolocation
Spectrum Manager
Conclusion
Gerald Chouinard, CRC

3. “Regional Area Network” Multipath absorption Window (Cyclic prefix )
January 2006
doc.: IEEE /0006r0
IEEE Standards
IEEE
RAN
“Regional Area Network”
10-30 km
Multipath absorption Window (Cyclic prefix )
0.25
2.2 μsec
0.8
75 μsec
The IEEE Working Group which is developing the WRAN standard is adding anotherr layer to the set of licensed-exempt wireless systems. It will be able to operate in the low-VHF (ch. 2-6), high-VHF (ch. 7-13) and UHF (ch. 14 to 51 and 69 where possible). It will use the standard TV channels, 6, 7 and 8 MHz wide. Each channel can carry some 20 Mbit/s capacity and its modulation (2000 carriers OFDMA) will be robust to long echoes (up to about 25 usec) found on these longer paths.
23, 27, 31 Mbit/s
BW= 6,7,8 MHz
MHz
Gerald Chouinard, CRC
Gerald Chouinard, CRC

4. Characteristics of 802.22 WRAN:
January 2006
doc.: IEEE /0006r0
Characteristics of WRAN:
Base station power: 100 W Antenna height: 75 m
User terminal (CPE) power: 4 W antenna height: 10 m
30 km
23 km
16 km
64-QAM
16-QAM
QPSK
Max throughput per 6 MHz: 23 Mbit/s (net: Mbit/s)
The service availability is defined as F(50, 90), that is one household over 2 can be reached at the edge of the coverage (unlike 1 over 4 over most of the coverage for WLAN as explained by STORM yesterday) (availability will be much better inside the coverage area) and once connection is feasible, its availability in time will be very high for stable service, i.e., 99.9%). This can be achieved with Customer Premise Equipment (CPE) transmit power of 4 W as specified by the FCC and a base station power of 100 W at 75 m antenna height for the maximum throughtput indicated. In order to re-use a DTV frequency, the base station will need to be located at some 30 km from the edge of the DTV coverage area. This will reduce to 1 km if a first adjacent channel is used. The CPEs can be located at 3 km from the edge of the DTV coverage area for the co-channel case and only 70 m for the first adjacent channel. Since it is considered that the distance between neighbor can be as small as 10 m, CPEs operating on first adjacent channels will not be allowed inside the DTV coverage area.
Gerald Chouinard, CRC
Gerald Chouinard, CRC

5. Outline Summary of 802.22 characteristics
Interference issues between long range and short range systems
Detection distance and interference distance
Detection threshold levels to coexist with
coexistence tools available to
Coexistence techniques in
Spectrum etiquette
On-channel re-use
on-channel coexistence TDMA capabilities
Terrestrial geolocation
Spectrum Manager
Conclusion
Gerald Chouinard, CRC

6. WRAN edge of coverage: 10.4 km
WRAN CPE
4 Watt
10 m outdoors
WRAN BS
4 Watt
30 m
WRAN edge of coverage: 10.4 km
Gerald Chouinard, CRC

7. Radius of detection of BS TX by 802.11= 330 m
WRAN
Radius of detection of BS TX by = 330 m
at -64 dBm level
WRAN CPE
4 Watt
10 m outdoors
WRAN BS
4 Watt
30 m
WRAN edge of coverage: 10.4 km
Gerald Chouinard, CRC

8. Radius of detection of BS TX by 802.11= 330 m
WRAN
Radius of detection of BS TX by = 330 m
at -64 dBm level
WRAN CPE
4 Watt
10 m outdoors
WRAN BS
4 Watt
30 m
Radius of Interference from the 100 mW portable unit= 2.2 km
WRAN edge of coverage: 10.4 km
Gerald Chouinard, CRC

9. On-axis radius of detection of CPE TX by 802.11= 300 m
WRAN
On-axis radius of detection of CPE TX by = 300 m
78 m in backlobe
Radius of detection of BS TX by = 330 m
at -64 dBm level
WRAN CPE
4 Watt
10 m outdoors
WRAN BS
4 Watt
30 m
Radius of Interference from the 100 mW portable unit= 2.2 km
WRAN edge of coverage: 10.4 km
Gerald Chouinard, CRC

10. On-axis radius of detection of CPE TX by 802.11= 300 m
WRAN
On-axis radius of detection of CPE TX by = 300 m
78 m in backlobe
Radius of detection of BS TX by = 330 m
at -64 dBm level
WRAN CPE
4 Watt
10 m outdoors
WRAN BS
4 Watt
30 m
On-axis radius of Interference from the 100 mW portable unit= 1.35 km
Radius of Interference from the 100 mW portable unit= 2.2 km
WRAN edge of coverage: 10.4 km
Gerald Chouinard, CRC

11. Outline Summary of 802.22 characteristics
Interference issues between long range and short range systems
Detection distance and interference distance
Detection threshold levels to coexist with
coexistence tools available to
Coexistence techniques in
Spectrum etiquette
On-channel re-use
on-channel coexistence TDMA capabilities
Terrestrial geolocation
Spectrum Manager
Conclusion
Gerald Chouinard, CRC

12. 802.11 Detection threshold level to coexist with 802.22
Required detection threshold in 6 MHz to limit the devices desensitization to 3 dB
Detection threshold = dBm (BS transmitted signal)
Detection threshold = -88 dBm (CPE transmitted signal)
Detection threshold = -104 dBm (BS signal received at CPE, 10 m)
Detection threshold = dBm (BS signal received at CPE, 1.5 m)
To be able to detect the downstream burst from the distant BS sending the DS/US-MAP
-120.9
Note that:
Typical sensitivity = -85 dBm
Typical SNR (QPSK, rate: 1/2) = 4.3 dB (Re: parameters-for-simulation.doc)
desensitization at these thresholds would be:
BS transmited signal = 2.3 dB
CPE transmitted signal = 3.7 dB
BS received signal at CPE (10 m) = 0.14 dB
BS received signal at CPE (1.5 m) = 0 dB
Gerald Chouinard, CRC

13. Outline Summary of 802.22 characteristics
Interference issues between long range and short range systems
Detection distance and interference distance
Detection threshold levels to coexist with
coexistence tools available to
Coexistence techniques in
Spectrum etiquette
On-channel re-use
on-channel coexistence TDMA capabilities
Terrestrial geolocation
Spectrum Manager
Conclusion
Gerald Chouinard, CRC

14. 802.22 Coexistence techniques
Gerald Chouinard, CRC

15. Spectrum Etiquette Co-channel consideration:
different operating channel for overlapping or adjacent cells
different first backup channel
Before
After
Gerald Chouinard, CRC

16. Spectrum Etiquette Adjacent-channel consideration:
Depending on adjacent rejection and dynamic range operation
Gerald Chouinard, CRC

17. Outline Summary of 802.22 characteristics
Interference issues between long range and short range systems
Detection distance and interference distance
Detection threshold levels to coexist with
coexistence tools available to
Coexistence techniques in
Spectrum etiquette
On-channel re-use
on-channel coexistence TDMA capabilities
Terrestrial geolocation
Spectrum Manager
Conclusion
Gerald Chouinard, CRC

18. On-channel re-use Techniques for on-channel re-use
CDMA: limited signal discrimination (X <25 dB)
OFDMA: average signal discrimination through FFT (25 < X <35 dB)
TDMA: very high signal discrimination (X > 35 dB) with appropriate time buffer to remove channel time spread
Given the potential large dynamic difference between fixed and portable applications, TDMA will be required.
Gerald Chouinard, CRC

19. Outline Summary of 802.22 characteristics
Interference issues between long range and short range systems
Detection distance and interference distance
Detection threshold levels to coexist with
coexistence tools available to
Coexistence techniques in
Spectrum etiquette
On-channel re-use
on-channel coexistence TDMA capabilities
Terrestrial geolocation
Spectrum Manager
Conclusion
Gerald Chouinard, CRC

20. 802.22 WRAN superframe and frame structure
Superframe = 160 ms
Superframe = 16 frames
Frame = 10 ms
Gerald Chouinard, CRC

21. 802.22 WRAN superframe and frame structure
Superframe = 160 ms
Superframe = 16 frames
Frame = 10 ms
Using the Self-coexistence window (5 symbols, 2.3 ms) for TDMA with other systems
Gerald Chouinard, CRC

22. 802.22 WRAN superframe and frame structure
Superframe = 160 ms
Superframe = 16 frames
Frame = 10 ms
Using the capability to schedule intra-frame quiet periods for sensing
Gerald Chouinard, CRC

23. 802.22 WRAN superframe and frame structure
Superframe = 160 ms
Superframe = 16 frames
Frame = 10 ms
Using the capability to shorten its frame under lower traffic
Gerald Chouinard, CRC

24. Outline Summary of 802.22 characteristics
Interference issues between long range and short range systems
Detection distance and interference distance
Detection threshold levels to coexist with
coexistence tools available to
Coexistence techniques in
Spectrum etiquette
On-channel re-use
on-channel coexistence TDMA capabilities
Terrestrial geolocation
Spectrum Manager
Conclusion
Gerald Chouinard, CRC

25. Terrestrial geolocation
January 2006
doc.: IEEE /0006r0
Terrestrial geolocation
Vernier-1 BS
Downstream
CPE
Upstream
CBP burst
Vernier-2
CPE
Vernier-1
Vernier-3
Besides satellite-based geolocation, the standard includes terrestrial geolocation using inherent capabilities of the OFDM based modulation and the coexistence beacon protocol bursts transmitted and received among CPEs
Propagation time measured between BS and its CPEs and among CPEs of the same cell using Fine Time Difference of Arrival: TDOA
Gerald Chouinard, CRC
Gerald Chouinard, CRC

26. Outline Summary of 802.22 characteristics
Interference issues between long range and short range systems
Detection distance and interference distance
Detection threshold levels to coexist with
coexistence tools available to
Coexistence techniques in
Spectrum etiquette
On-channel re-use
on-channel coexistence TDMA capabilities
Terrestrial geolocation
Spectrum Manager
Conclusion
Gerald Chouinard, CRC

27. 802.22 Spectrum Manager Spectrum Manager Policies Spectrum Sensing
Channel Set Management
Policies
Subscriber Station Registration and Tracking
Spectrum Manager
Geo-location
Self Co-existence
Incumbent Database Service
Spectrum Sensing
Incumbent
Database
Gerald Chouinard, CRC

28. Outline Summary of 802.22 characteristics
Interference issues between long range and short range systems
Detection distance and interference distance
Detection threshold levels to coexist with
coexistence tools available to
Coexistence techniques in
Spectrum etiquette
On-channel re-use
Improving operation in presence of CSMA-CA transmissions
Terrestrial geolocation
Spectrum manager
Conclusion
Gerald Chouinard, CRC

29. Conclusions
Current CSMA-CA based detection thresholds are not sufficient to enable coexistence with
WG has been developing a standard based on protecting incumbents and enabling self-coexistence since the very beginning
has established spectrum sharing techniques that can be readily adapted to enable coexistence with other 802 technologies
spectrum manager is capable of autonomously deciding which coexistence mechanism to use and how
will consider providing interface between its spectrum manager and coexistence manager
will be happy to help to ensure fair coexistence amongts different 802 technologies in the TVWS
Gerald Chouinard, CRC

30. January 2006
doc.: IEEE /0006r0
References
IEEE P802.22™/ DRAFTv4.0 Draft Standard for Wireless Regional Area Networks Part 22: Cognitive Wireless RAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Policies and procedures for operation in the TV Bands, August 2010
Interference between WRAN and Portable Devices.xls
Gerald Chouinard, CRC
Gerald Chouinard, CRC