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Gerald Chouinard, CRC
Slide 1
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
802.22 Coexistence Aspects
Name Company Address Phone email Gerald Chouinard Communications
Research Centre, Canada
3701 Carling Ave. Ottawa, Ontario Canada K2H 8S2
(613) 998-2500 [email protected]
Author:
Notice: This document has been prepared to assist IEEE 802.22. 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.
Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.11.
Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures <http://standards.ieee.org/guides/bylaws/sb-bylaws.pdf>, including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair Carl R. Stevenson <[email protected]> as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.11 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at <[email protected]>.
AbstractThis contribution summarizes graphically the coexistence features developed in the 802.22 Draft Standard.
Gerald Chouinard, CRC
Slide 2
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
Outline
• Summary of 802.22 characteristics
• 802.11 Interference issues– Detection distance and interference distance
– Detection threshold levels to coexist with 802.22
• 802.22 coexistence tools available to 802.19– Coexistence techniques in 802.22
• Spectrum etiquette• On-channel re-use
– Improving 802.22 operation in presence of 802.11 CSMA-CA transmissions
– Terrestrial geolocation
• Conclusion
Gerald Chouinard, CRC
Slide 3
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
IEEE Standards
IEEE 802.22
RAN
“Regional Area Network”
10-30 km
54 - 862 MHz
Multipath absorption Window
(Cyclic prefix )
0.252.2 μsec
0.8
75 μsec
23, 27, 31 Mbit/sBW= 6,7,8 MHz
Gerald Chouinard, CRC
Slide 4
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
Characteristics of 802.22 WRAN:
30 km23 km
16 km
QPSK
16-QAM64-QAM
Max throughput per 6 MHz:23 Mbit/s (net: 19.44 Mbit/s)
Base station power: 100 WAntenna height: 75 m
User terminal (CPE) power: 4 Wantenna height: 10 m
Gerald Chouinard, CRC
Slide 5
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
Outline
• Summary of 802.22 characteristics
• 802.11 Interference issues– Detection distance and interference distance
– Detection threshold levels to coexist with 802.22
• 802.22 coexistence tools available to 802.19– Coexistence techniques in 802.22
• Spectrum etiquette• On-channel re-use
– Improving 802.22 operation in presence of 802.11 CSMA-CA transmissions
– Terrestrial geolocation
• Conclusion
Gerald Chouinard, CRC
Slide 6
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
802.22 WRAN
WRAN BS4 Watt30 m
WRAN CPE4 Watt
10 m outdoors
WRAN edge of coverage: 10.4 km
Gerald Chouinard, CRC
Slide 7
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
802.22 WRAN
WRAN BS4 Watt30 m
WRAN CPE4 Watt
10 m outdoors
WRAN edge of coverage: 10.4 km
Radius of detection of BS TX by
802.11= 330 mat -64 dBm level
Gerald Chouinard, CRC
Slide 8
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
802.22 WRAN
WRAN BS4 Watt30 m
WRAN CPE4 Watt
10 m outdoors
WRAN edge of coverage: 10.4 km
Radius of detection of BS TX by
802.11= 330 mat -64 dBm level
Radius of Interference from
the 100 mW portable unit= 2.2 km
Gerald Chouinard, CRC
Slide 9
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
802.22 WRAN
WRAN BS4 Watt30 m
WRAN CPE4 Watt
10 m outdoors
WRAN edge of coverage: 10.4 km
Radius of detection of BS TX by
802.11= 330 mat -64 dBm level
On-axis radius of detection of CPE TX
by 802.11= 300 m78 m in backlobe
Radius of Interference from
the 100 mW portable unit= 2.2 km
Gerald Chouinard, CRC
Slide 10
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
802.22 WRAN
WRAN BS4 Watt30 m
WRAN CPE4 Watt
10 m outdoors
WRAN edge of coverage: 10.4 km
Radius of detection of BS TX by
802.11= 330 mat -64 dBm level
On-axis radius of detection of CPE TX
by 802.11= 300 m78 m in backlobe
Radius of Interference from
the 100 mW portable unit= 2.2 km
On-axis radius of Interference from
the 100 mW portable unit= 1.35 km
Gerald Chouinard, CRC
Slide 11
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
Outline
• Summary of 802.22 characteristics
• 802.11 Interference issues– Detection distance and interference distance
– Detection threshold levels to coexist with 802.22
• 802.22 coexistence tools available to 802.19– Coexistence techniques in 802.22
• Spectrum etiquette• On-channel re-use
– Improving 802.22 operation in presence of 802.11 CSMA-CA transmissions
– Terrestrial geolocation
• Conclusion
Gerald Chouinard, CRC
Slide 12
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
802.11 Detection threshold level to coexist with 802.22
• Required 802.11 detection threshold in 6 MHz to limit the 802.22 devices desensitization to 3 dB– Detection threshold = -90.8 dBm (BS transmitted signal)– Detection threshold = -88 dBm (CPE transmitted signal)– Detection threshold = -104 dBm (BS signal received at CPE, 10 m)– Detection threshold = -120.9 dBm (BS signal received at CPE, 1.5 m)
• Note that:– Typical 802.11 sensitivity = -85 dBm– Typical SNR (QPSK, rate: 1/2) = 4.3 dB
(Re: 19-07-0011-15-0000-parameters-for-simulation.doc)– 802.11 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
To be able to detect the downstream burst from the distant BS sending the DS/US-MAP
-120.9
Gerald Chouinard, CRC
Slide 13
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
Outline
• Summary of 802.22 characteristics
• 802.11 Interference issues– Detection distance and interference distance
– Detection threshold levels to coexist with 802.22
• 802.22 coexistence tools available to 802.19– Coexistence techniques in 802.22
• Spectrum etiquette• On-channel re-use
– Improving 802.22 operation in presence of 802.11 CSMA-CA transmissions
– Terrestrial geolocation
• Conclusion
Gerald Chouinard, CRC
Slide 14
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
802.22 Coexistence techniques
(Exchange of information between BSs through CPEsusing the self-coexistence window)
Coexistence beacon protocol
On
-dem
and
fram
eco
nte
nti
on
Sp
ectr
um
etiq
uet
te
Gerald Chouinard, CRC
Slide 15
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
Spectrum Etiquette
1, 2, 7 3, 4, 2, 6, 7
5, 6, 2, 7, 84, 8, 2, 6, 7
3, 7, 2, 5, 8
6, 4, 2, 5, 7 8, 5, 2, 4, 7
(a) (b)
7, 5 3, 4, 6
5, 6, 2, 84, 8, 2, 6
3, 2, 5, 8
6, 4, 2, 5 8, 5, 2, 4
1 2
• Co-channel consideration:– different operating channel for overlapping or adjacent cells– different first backup channel
Gerald Chouinard, CRC
Slide 16
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
Frequency Separation form the Equipment’s Channel Center, Δf (MHz)
27 dBr
55 dBr
FCCR&O 08-260
ICRSS-196
802.16 scaled to 6 MHz
Frequency Separation form the Equipment’s Channel Center, Δf (MHz)
27 dBr
FCCR&O 08-260
ICRSS-196
Frequency Separation form the Equipment’s Channel Center, Δf (MHz)
27 dBr
55 dBr
FCCR&O 08-260
ICRSS-196
802.16 scaled to 6 MHz
Spectrum Etiquette• Adjacent-channel consideration:
– Depending on adjacent rejection and dynamic range operation
Gerald Chouinard, CRC
Slide 17
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
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) withappropriate 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
Slide 18
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
Outline
• Summary of 802.22 characteristics
• 802.11 Interference issues– Detection distance and interference distance
– Detection threshold levels to coexist with 802.22
• 802.22 coexistence tools available to 802.19– Coexistence techniques in 802.22
• Spectrum etiquette• On-channel re-use
– Improving 802.22 operation in presence of 802.11 CSMA-CA transmissions
– Terrestrial geolocation
• Conclusion
Gerald Chouinard, CRC
Slide 19
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
802.22 WRAN superframe and frame structure
frame 0
Superframe n-1 Superframe n Superframe n+1
SuperframePreamble
SCH
. . .
FramePreamble
160 ms
frame 1
10 ms
frame 15
DS sub-frame
TTG
RTG
US sub-frame(smallest US burst portion on a given subchannel= 7 symbols)
26 to 42 symbols corresponding to bandwidths from 6 MHz to 8 MHz and cyclic prefixes from 1/ 4 to 1/ 32
Fra
me P
ream
ble
FCH
DS-
MAP
Bur
st 1DCD
Bur
st 2
tim
e buff
er
tim
e buff
er
Self-c
oexi
stence
win
dow
(4 o
r 5 s
ymbols
when s
chedule
d)
Burst 1
60 s
ubch
anne
ls
Burst 2
Burst 3more than 7 OFDMA symbols
Burst
Burst n
Burst
Bur
st m
Ranging/ BW request/ UCS notification
Burst
Burst
Bursts
Bur
sts
... Time...
US-
MAP
US-
MAP
UCD
10 ms 10 ms
FramePreamble
FramePreamble
Superframe = 160 ms
Frame = 10 ms
Superframe = 16 frames
Gerald Chouinard, CRC
Slide 20
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
802.22 WRAN superframe and frame structure
frame 0
Superframe n-1 Superframe n Superframe n+1
SuperframePreamble
SCH
. . .
FramePreamble
160 ms
frame 1
10 ms
frame 15
DS sub-frame
TTG
RTG
US sub-frame(smallest US burst portion on a given subchannel= 7 symbols)
26 to 42 symbols corresponding to bandwidths from 6 MHz to 8 MHz and cyclic prefixes from 1/ 4 to 1/ 32
Fra
me P
ream
ble
FCH
DS-
MAP
Bur
st 1DCD
Bur
st 2
tim
e buff
er
tim
e buff
er
Self-c
oexi
stence
win
dow
(4 o
r 5 s
ymbols
when s
chedule
d)
Burst 1
60 s
ubch
anne
ls
Burst 2
Burst 3more than 7 OFDMA symbols
Burst
Burst n
Burst
Bur
st m
Ranging/ BW request/ UCS notification
Burst
Burst
Bursts
Bur
sts
... Time...
US-
MAP
US-
MAP
UCD
10 ms 10 ms
FramePreamble
FramePreamble
Superframe = 160 ms
Frame = 10 ms
Superframe = 16 frames
Using the Self-coexistence window (5 symbols, 2.3 ms) for TDMA with other
systems
Gerald Chouinard, CRC
Slide 21
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
802.22 WRAN superframe and frame structure
frame 0
Superframe n-1 Superframe n Superframe n+1
SuperframePreamble
SCH
. . .
FramePreamble
160 ms
frame 1
10 ms
frame 15
DS sub-frame
TTG
RTG
US sub-frame(smallest US burst portion on a given subchannel= 7 symbols)
26 to 42 symbols corresponding to bandwidths from 6 MHz to 8 MHz and cyclic prefixes from 1/ 4 to 1/ 32
Fra
me P
ream
ble
FCH
DS-
MAP
Bur
st 1DCD
Bur
st 2
tim
e buff
er
tim
e buff
er
Self-c
oexi
stence
win
dow
(4 o
r 5 s
ymbols
when s
chedule
d)
Burst 1
60 s
ubch
anne
ls
Burst 2
Burst 3more than 7 OFDMA symbols
Burst
Burst n
Burst
Bur
st m
Ranging/ BW request/ UCS notification
Burst
Burst
Bursts
Bur
sts
... Time...
US-
MAP
US-
MAP
UCD
10 ms 10 ms
FramePreamble
FramePreamble
Superframe = 160 ms
Frame = 10 ms
Superframe = 16 frames
Using the 802.22 capability to shorten its
frame under lower traffic
Gerald Chouinard, CRC
Slide 22
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
802.22 WRAN superframe and frame structure
frame 0
Superframe n-1 Superframe n Superframe n+1
SuperframePreamble
SCH
. . .
FramePreamble
160 ms
frame 1
10 ms
frame 15
DS sub-frame
TTG
RTG
US sub-frame(smallest US burst portion on a given subchannel= 7 symbols)
26 to 42 symbols corresponding to bandwidths from 6 MHz to 8 MHz and cyclic prefixes from 1/ 4 to 1/ 32
Fra
me P
ream
ble
FCH
DS-
MAP
Bur
st 1DCD
Bur
st 2
tim
e buff
er
tim
e buff
er
Self-c
oexi
stence
win
dow
(4 o
r 5 s
ymbols
when s
chedule
d)
Burst 1
60 s
ubch
anne
ls
Burst 2
Burst 3more than 7 OFDMA symbols
Burst
Burst n
Burst
Bur
st m
Ranging/ BW request/ UCS notification
Burst
Burst
Bursts
Bur
sts
... Time...
US-
MAP
US-
MAP
UCD
10 ms 10 ms
FramePreamble
FramePreamble
Superframe = 160 ms
Frame = 10 ms
Superframe = 16 frames
Using the 802.22 capability to schedule
intra-frame quiet periods for sensing
Gerald Chouinard, CRC
Slide 23
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
Outline
• Summary of 802.22 characteristics
• 802.11 Interference issues– Detection distance and interference distance
– Detection threshold levels to coexist with 802.22
• 802.22 coexistence tools available to 802.19– Coexistence techniques in 802.22
• Spectrum etiquette• On-channel re-use
– Improving 802.22 operation in presence of 802.11 CSMA-CA transmissions
– Terrestrial geolocation
• Conclusion
Gerald Chouinard, CRC
Slide 24
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
Improving 802.22 operation in presence of 802.11 CSMA-CA transmissions
• 802.11 CSMA-CA based transmission would interfere with the 802.22 frames where critical information is sent, that is superframe control header (SCH), frame contol header (FCH and the DS\US-MAP.
• 802.22 is considering stretching the preamble periods so that the CSMA-CA burst is completed when this critical information is sent by the BS.
• Repeating the superframe preamble and frame preambles a controlled number of times will allow trade-off between 802.22 robustness against CSMA-CA transmissions and transmission efficiency.
• 802.19 Inter-system coexistence will need to limit the length of the CSMA-CA bursts to make this approach effective without excessively affecting the systems throughput.
Gerald Chouinard, CRC
Slide 25
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
Outline
• Summary of 802.22 characteristics
• 802.11 Interference issues– Detection distance and interference distance
– Detection threshold levels to coexist with 802.22
• 802.22 coexistence tools available to 802.19– Coexistence techniques in 802.22
• Spectrum etiquette• On-channel re-use
– Improving 802.22 operation in presence of 802.11 CSMA-CA transmissions
– Terrestrial geolocation
• Conclusion
Gerald Chouinard, CRC
Slide 26
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
Terrestrial geolocation
BS
Vernier-1
Vernier-2
CPE 1
Downstream
Upstream
• Besides satellite-based geolocation, the 802.22 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
Vernier-3 CPE 2
CBP burst
Vernier-1
Gerald Chouinard, CRC
Slide 27
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
Outline
• Summary of 802.22 characteristics
• 802.11 Interference issues– Detection distance and interference distance
– Detection threshold levels to coexist with 802.22
• 802.22 coexistence tools available to 802.19– Coexistence techniques in 802.22
• Spectrum etiquette• On-channel re-use
– Improving 802.22 operation in presence of 802.11 CSMA-CA transmissions
– Terrestrial geolocation
• Conclusion
Gerald Chouinard, CRC
Slide 28
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
Conclusions• Current 802.11 CSMA-CA based detection thresholds
are not sufficient to enable coexistence with 802.22• 802.22 WG has been developing a standard based on
protecting incumbents and enabling self-coexistence since the very beginning
• 802.22 has established spectrum sharing techniques that can be readily adapted to enable coexistence with other 802 technologies
• 802.22 spectrum manager is capable of autonomously deciding which coexistence mechanism to use and how
• 802.22 will consider providing interface between its spectrum manager and 802.19 coexistence manager
• 802.22 will be happy to help 802.19 to ensure fair coexistence amongts different 802 technologies in the TVWS
Gerald Chouinard, CRC
Slide 29
doc.: IEEE 802.22-10/0121r0
Submission
July 2010
References1. IEEE P802.22™/ DRAFTv3.0 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, April 2010