doc.: ieee 802.22-10/0121r0 submission july 2010 gerald chouinard, crcslide 1 802.22 coexistence...

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.


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


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


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


Slide 5

doc.: IEEE 802.22-10/0121r0

Submission

July 2010

Outline








• Conclusion


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


Slide 7

doc.: IEEE 802.22-10/0121r0

Submission

July 2010

802.22 WRAN

WRAN BS4 Watt30 m

WRAN CPE4 Watt

10 m outdoors


Radius of detection of BS TX by

802.11= 330 mat -64 dBm level


Slide 8

doc.: IEEE 802.22-10/0121r0

Submission

July 2010

802.22 WRAN

WRAN BS4 Watt30 m

WRAN CPE4 Watt

10 m outdoors



802.11= 330 mat -64 dBm level

Radius of Interference from

the 100 mW portable unit= 2.2 km


Slide 9

doc.: IEEE 802.22-10/0121r0

Submission

July 2010

802.22 WRAN

WRAN BS4 Watt30 m

WRAN CPE4 Watt

10 m outdoors



802.11= 330 mat -64 dBm level

On-axis radius of detection of CPE TX

by 802.11= 300 m78 m in backlobe




Slide 10

doc.: IEEE 802.22-10/0121r0

Submission

July 2010

802.22 WRAN

WRAN BS4 Watt30 m

WRAN CPE4 Watt

10 m outdoors



802.11= 330 mat -64 dBm level

On-axis radius of detection of CPE TX

by 802.11= 300 m78 m in backlobe



On-axis radius of Interference from



Slide 11

doc.: IEEE 802.22-10/0121r0

Submission

July 2010

Outline








• Conclusion


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


Slide 13

doc.: IEEE 802.22-10/0121r0

Submission

July 2010

Outline








• Conclusion


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


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


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


27 dBr

FCCR&O 08-260

ICRSS-196


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


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.


Slide 18

doc.: IEEE 802.22-10/0121r0

Submission

July 2010

Outline








• Conclusion


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


Slide 20

doc.: IEEE 802.22-10/0121r0

Submission

July 2010


frame 0


SuperframePreamble

SCH

. . .

FramePreamble

160 ms

frame 1

10 ms

frame 15

DS sub-frame

TTG

RTG



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

Burst n

Burst

Bur

st m


Burst

Burst

Bursts

Bur

sts

... Time...

US-

MAP

US-

MAP

UCD

10 ms 10 ms

FramePreamble

FramePreamble

Superframe = 160 ms

Frame = 10 ms


Using the Self-coexistence window (5 symbols, 2.3 ms) for TDMA with other

systems


Slide 21

doc.: IEEE 802.22-10/0121r0

Submission

July 2010


frame 0


SuperframePreamble

SCH

. . .

FramePreamble

160 ms

frame 1

10 ms

frame 15

DS sub-frame

TTG

RTG



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

Burst n

Burst

Bur

st m


Burst

Burst

Bursts

Bur

sts

... Time...

US-

MAP

US-

MAP

UCD

10 ms 10 ms

FramePreamble

FramePreamble

Superframe = 160 ms

Frame = 10 ms


Using the 802.22 capability to shorten its

frame under lower traffic


Slide 22

doc.: IEEE 802.22-10/0121r0

Submission

July 2010


frame 0


SuperframePreamble

SCH

. . .

FramePreamble

160 ms

frame 1

10 ms

frame 15

DS sub-frame

TTG

RTG



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

Burst n

Burst

Bur

st m


Burst

Burst

Bursts

Bur

sts

... Time...

US-

MAP

US-

MAP

UCD

10 ms 10 ms

FramePreamble

FramePreamble

Superframe = 160 ms

Frame = 10 ms


Using the 802.22 capability to schedule

intra-frame quiet periods for sensing


Slide 23

doc.: IEEE 802.22-10/0121r0

Submission

July 2010

Outline








• Conclusion


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.


Slide 25

doc.: IEEE 802.22-10/0121r0

Submission

July 2010

Outline








• Conclusion


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


Slide 27

doc.: IEEE 802.22-10/0121r0

Submission

July 2010

Outline








• Conclusion


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


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

doc.: ieee 802.22-10/0121r0 submission july 2010 gerald chouinard, crcslide 1 802.22 coexistence...

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