doc.: ieee 802.22-05/0097r0 submission november 2005 eli sofer, runcom | wendong hu,...

November 2005

Eli Sofer, Runcom | Wendong Hu, STMicroelectronics

Slide 1

doc.: IEEE 802.22-05/0097r0

Submission

IEEE 802.22 WRAN Standard PHY/MAC Proposal IEEE P802.22 Wireless RANs Date: 2005-11-07

Name Company Address Phone email

Eli Sofer Runcom 2 Hachoma St. Rishon Lezion,

Israel

+972 544 997 996

[email protected]

Wendong Hu STMicroelectronics 1060 E. Brokaw Rd. San Jose, CA 95131

U.S.A. 1-408-467-8410 [email protected]

Authors:

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 802.22.

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 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 802.22 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at [email protected].>

November 2005


Slide 2

doc.: IEEE 802.22-05/0097r0

Submission

Abstract

In this presentation, we provide a technical overview of our full proposal for the Physical (PHY) layer and the Medium Access Control (MAC) layer of the IEEE 802.22 Wireless Regional Networks (WRAN) Standard.

November 2005


Slide 3

doc.: IEEE 802.22-05/0097r0

Submission

OFDMA based PHY proposalOFDMA based PHY proposal

November 2005


Slide 4

doc.: IEEE 802.22-05/0097r0

Submission

Proposal Outline: PHY• Requirements & OFDMA basic Features• PHY preliminary proposal• Base-Band processing chain• Down-Link• Up-Link• Hybrid ARQ• Diversity Schemes• Simulation Results

November 2005


Slide 5

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Submission

OFDMA (2k FFT) on both Uplink and Downlink enabling a highly flexible and dynamic network resource management, handling of multipath, efficient cellular rollout, efficient multiple access operation and handling of narrow channels (voice) as well as broadband channels (video, data), other key features:

• Use of 6 MHz channel BW or two adjunct 6MHz channels• Power concentration (up to 15db) to boost selective sub-channels

to increase range• Efficient use of operator spectrum resources• Brick wall spectral mask• Supports adaptive modulation on a per sub-channel basis• Excellent handling of interference -- Narrow band interference is

rejected through frequency domain processing, while Burst interference is rejected by virtue of the OFDMA symbol length and the per sub-channel interleaving

• Provide bandwidth to many subscribers simultaneously• OFDMA supports advanced ranging based on identification of

CDMA codes

Key design Considerations

November 2005


Slide 6

doc.: IEEE 802.22-05/0097r0

Submission

OFDMA basic features

November 2005


Slide 7

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Submission

As the FFT size gets bigger, the spectral mask improves, the amount of Guard Interval needed to mitigate the channel reduces, and the phase noise demands increase (there is no implementation problem).

OFDM Spectrum

November 2005


Slide 8

doc.: IEEE 802.22-05/0097r0

Submission

Using OFDMA/TDMA, Sub Channels are allocated in the Frequency Domain, and OFDM Symbols allocated in the Time Domain.

OFDMA-TDMA Principles

TDMA

TDMA\OFDMA

t

N

m

November 2005


Slide 9

doc.: IEEE 802.22-05/0097r0

Submission

DownLink OFDMA Symbol (example)

Total Frequency BandGuard Band Guard Band

Symbol PilotsSub-Channel Data Carriers

November 2005


Slide 10

doc.: IEEE 802.22-05/0097r0

Submission

PHY preliminary proposal

November 2005


Slide 11

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Submission

Duplexing Technique • TDD

Multiple Access Method • TDMA/OFDMAOFDM Symbols allocated by TDMASub-Carriers within an OFDM Symbol allocated by

OFDMA

Diversity• Frequency, Time, Code, Space

Basics

November 2005


Slide 12

doc.: IEEE 802.22-05/0097r0

Submission

TDD (Time Division Duplexing) Uses the same frequency for the Downlink and the Uplink.

In any configuration, the access method is OFDMA/TDMA .

F1 - Frequency band

UpLink

F1 - Frequency band

DownLink

Duplexing - Principles

November 2005


Slide 13

doc.: IEEE 802.22-05/0097r0

Submission

Frame Structure Allowing Flexibility in DL/UL segmentation

3 possible Preamble structure

FCH and MAP transmitted in PUSC (for better coverage)

Flexible Subchannels allocation per sector on a frame by frame basis

All zones are flexible to produce any scenario needed (reuse =1, reuse < 1, STC/AAS)

Zone may be used as broadcast [SFN] with permutation adjustment

STC/AAS may be combined with regular mode of operation

November 2005


Slide 14

doc.: IEEE 802.22-05/0097r0

Submission

Preambles

3 possible Preamble structure, more than 114 preambles over all

Preambles are designed for low PAPR (about 5dB or less)

Preambles are boosted due to low PAPR

Preambles are used for channel estimation, frequency estimation, timing estimation and cell monitoring

November 2005


Slide 15

doc.: IEEE 802.22-05/0097r0

Submission

Base-Band Processing Chain

November 2005


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Submission

Base-Band Processing Chain

• Randomization• Coding

– Tail Biting Convolutional coding (mandatory)– CTC/BTC/Zero Tail Convolutional coding

(optional)• Block size depend on code/modulation/coding rate used

and HARQ usage• Block size is enlarged as allocation get bigger, limited by a

law to constrain decoder complexity (concatenation rules)• Bit-Interleaving over each encoded block

November 2005


Slide 17

doc.: IEEE 802.22-05/0097r0

Submission

DownLink/UpLink Block Diagram

Randomiz-ation

Bitinterleaving

Sub-ChannelMapper

IFFT

De-Randomization

BitDeinterle-

aving

Sub-ChannelDemapper

and AdapterFFT

DownLink/UpLink Encoding and Modulation

DownLink/UpLink Demodulation and Decoding

DownLinkTx

Low MacData From MACand Adaptation

Layers

Sub-ChannelAllocation and

BoostingFEC Encoder

DownLinkRx

ChannelEstimation

Low MacData To MAC

and AdaptationLayers

FEC Decoder

November 2005


Slide 18

doc.: IEEE 802.22-05/0097r0

Submission

• Dual binary CTC – The best solution for high coding gain using small blocks.– Reduced decoding power per bit compared to regular CTC.– Gives very good performance even for small number of iterations

Coding Schemes

November 2005


Slide 19

doc.: IEEE 802.22-05/0097r0

Submission

Down-Link

November 2005


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Submission

There are two basic modes of operation:

• Reuse smaller then 1: Sub-Channels (SC) are divided up to 3 Logical-Bands PUSC (Partial use of SC), the structure enables each Logical-Band to have the frequency diversity properties of the full channel, but using only a part of the frequency carriers. The splitting will enable to boost the transmitted carriers on the expense of the un-transmitted carriers ~(4.8 dB).

• Reuse Of 1: Using PUSC or FUSC (Full use of SC) where all subchannels are used. Cell configuration differ by different permutation enabling a reuse of 1.

Reuse

November 2005


Slide 21

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Submission

• The Carriers of each Sub-Channel are spread all over the usable frequency for best frequency diversity.

• The allocation by permutation gives an excellent Reuse factor - almost 1.

• The allocation by permutation give an excellent interference spreading and averaging.

Using Special Permutations for carrier allocation

November 2005


Slide 22

doc.: IEEE 802.22-05/0097r0

Submission

DownLink Allocation example

(each color - different allocation)

FCH

Time

Sub-channel

16

0

0 2 4 6 10 12 14 16 18 20 22 24 26 28 30

Frame start (n) Frame start (n+1)

DL UL

Pream

ble

DL

and

UL

MA

P

328

Burst#1

Burst #3

Burst #2

Burst #7

34 36 38 40 42

Burst #4

Burst #5

Burst #6

November 2005


Slide 23

doc.: IEEE 802.22-05/0097r0

Submission

• Forward APC per Sub-Channel• Improves the coverage and reduces the interference

between sectors in both Uplink and Downlink• Enabling the same link budget in the Uplink, for a

much smaller PA at the user side

UpLink

Frequency band

DownLink

Frequency band

Power Control

November 2005


Slide 24

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Submission

Up-Link

November 2005


Slide 25

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Submission

• FFT size : 2048

• Guard Intervals : ¼, 1/8, 1/16, 1/32

• Coding : Convolutional/Convolutional Turbo Code (CTC)/BTC, with coding rates = ½, 2/3, ¾, 5/6

• Additional repetition coding of X2, X4 and X6

• QPSK, 16QAM, 64QAM adaptive modulation

• Different Preamble structure for each sector

• Pilots embedded within the Symbol Structure(FUSC), or associated per allocation of subchannels (PUSC).

• 60 Sub-Channels of 48 data subcarriers each (PUSC)

• 32 Sub-Channels of 48 data carriers each (FUSC)

DownLink Specification

November 2005


Slide 26

doc.: IEEE 802.22-05/0097r0

Submission

• Slot Structure is defined differently in each mode: one Sub-channel in the Frequency domain and 1 OFDMA time symbols in the time domain (FUSC), one Sub-Channel in the frequency domain and two OFDMA symbols in the time domain (PUSC). Each slot consists of 48 data modulated carriers.

• Adaptive Modulation and Coding per Allocation in the Down-Link

• Forward APC controlling (+9dB) – (-18dB) digital gain on the transmitted Sub-Channel

DownLink Specification

November 2005


Slide 27

doc.: IEEE 802.22-05/0097r0

Submission

DownLink 1

Planned for best Speed / delay spread performance

Each Cluster can be estimated by itself (self contained)

Major Groups include 24/16 clusters (12/8 Subchannels), for an overall 60 Subchannels

60 permutations are possible

Subchannel carriers are spread all over the specific Major Group’s clusters using RS permutation

Clusters are spread all over the spectrum using a permutation

November 2005


Slide 28

doc.: IEEE 802.22-05/0097r0

Submission

Total Frequency band

Guard Band

Guard Band

cluster 0 cluster 1

cluster 2cluster 3

cluster 119cluster 118

1. Dividing the subcarriers into 120 physical clusters. Each cluster contains 14 adjunct subcarriers:

DownLink Subcarriers allocation

November 2005


Slide 29

doc.: IEEE 802.22-05/0097r0

Submission

DownLink 2

Planned for best Speed / delay spread performance

Planned for a reuse of 1

Pilot periodicity of 2 symbols

32 Subchannels per symbol

32 permutations are possible

Subchannel carriers are spread all over the spectrum using RS series

All Symbol is estimated as a contiguous block

November 2005


Slide 30

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Submission

• FFT size : 2048

• Guard Intervals : ¼, 1/8, 1/16, 1/32

• Coding : Convolutional/Convolutional Turbo Code (CTC)/BTC, with coding rates = 1/2, 2/3, 3/4, 5/6

• Additional repetition coding of X2, X4 and X6

• PUSC/O-PUSC/AMC/TUSC Subchannel structures

• QPSK, 16QAM, 64QAM modulation

• 6 Tiles per slot (PUSC), 6 Tiles per slot (O-PUSC - optional), 6 Bins per slot (AMC – optional)

UpLink Specification

November 2005


Slide 31

doc.: IEEE 802.22-05/0097r0

Submission

• User Can be allocated 1 up to the maximum mini/regular Sub-Channels allocated to the sector

• Ranging Sub-Channels for User Ranging and fast Band-Width Request by using CDMA over OFDMA technique.

• Supporting optional Space Time Coding employing Alamouti STC and MIMO operation.

• Supporting optional Adaptive Array.

UpLink Specification

November 2005


Slide 32

doc.: IEEE 802.22-05/0097r0

Submission

UpLink Data Mapping

Mapping is performed in time axis first, per allocation, for the length of the UL relevant zone

Mapping needs only one axis of description (saves signaling overhead)

Mapping takes advantage of the power concentration as much as possible

November 2005


Slide 33

doc.: IEEE 802.22-05/0097r0

Submission

Up-Link CDMA on OFDMARanging and Bandwidth request

November 2005


Slide 34

doc.: IEEE 802.22-05/0097r0

Submission

• The CDMA like synchronization is achieved by allocating several of the usable Sub-Channels for the Ranging process, the logic unit they consist is called a Ranging Sub-Channel.

• Onto the Ranging Sub-Channel users modulate a Pseudo Noise (PN) sequence using BPSK modulation

• The Base Station detects the different sequences and uses the CIR that he derives from the sequences for:– Time and power synchronization– Decide on the user modulation and coding

Using CDMA like modulation for Ranging

November 2005


Slide 35

doc.: IEEE 802.22-05/0097r0

Submission

Ranging Signals

• Using CDMA over OFDMA modulation• ranging designed for Reuse of 1 and Reuse <1• Short ranging is used for BW request and periodic

ranging• Amount of Codes for each purpose is set by the MAC• Each sector has its own ranging codes• Using 144 Subcarriers as the basic transmission block

(6 data Subchannels of the mandatory UL mode)• BPSK modulation onto used carriers

November 2005


Slide 36

doc.: IEEE 802.22-05/0097r0

Submission

• Using the CDMA over OFDMA ranging method enables:

• A very robust mechanism for ranging

• The same mechanism for timing and power ranging

• A very efficient mechanism for maintenance ranging

• A very efficient mechanism for bandwidth request

• Latency is improved by factor of 4, efficiency by factor of 6

OFDMA using large FFT – The best Solution

0 1 2 3 4 5 6 7 8 9 100

0.5

1

1.5

2

2.5

Collision expectation value

Su

ce

ssfu

l B

W r

eq

ue

sts

pe

r slo

t

November 2005


Slide 37

doc.: IEEE 802.22-05/0097r0

Submission

Hybrid ARQ (HARQ)

November 2005


Slide 38

doc.: IEEE 802.22-05/0097r0

Submission

• To be used to overcome unknown channel conditions. • Whenever the first transmitted block fails to decode, the

decoder use the ACK/NACK protocol to request additional portion of the encoded block.

• Second transmission of the block may be a repetition of the first one and/or additional parity bits.

• The decoder combines the sum of all transmission and attempts to decode. This scheme is repeated until successful or dropped by the MAC layer.

• Incremental Redundancy (IR) and Chase combining H-ARQ schemes.

HARQ Operation

November 2005


Slide 39

doc.: IEEE 802.22-05/0097r0

Submission

LL

R

De

-In

terl

ea

ver

CC

/'CT

C F

EC

De

cod

er

CR

Cchannelestimator

Transmit theACK/NAK

ACK/NAK

H-ARQControl &memory

ACK/NACK generated in the PHY layer

November 2005


Slide 40

doc.: IEEE 802.22-05/0097r0

Submission

Diversity Schemes

November 2005


Slide 41

doc.: IEEE 802.22-05/0097r0

Submission

OFDMA space-time coding

• Transmit diversity (BST)• Receive diversity (BST)

– Use two receive chains– Combine the signals in the frequency domain– Equivalent channel response combines the best of both receive chains

• Diversity gain is 5-20dB (omni antennas)

Antenna #2

Antenna #1

Frequency

Amplitude(dB)

Frequency

Amplitude(dB)

Combined

Combine twoantennas

November 2005


Slide 42

doc.: IEEE 802.22-05/0097r0

Submission

Txdiversityencoder

IFFT DACFilter RF

IFFT DACFilter RF

Subcarrier modulation

IFFT input packing

Tx

Rx

RF DAC Filter FFT Diversity Combiner

Sub-channel demod.

Log-Likelihood

ratiosDecoder

STC

November 2005


Slide 43

doc.: IEEE 802.22-05/0097r0

Submission

RF DAC Filter FFT

Sub-channel demod.

Log-Likelihood

ratiosDecoder

Rx

RF DAC Filter FFT Diversity Combiner

IFFT DACFilter RF Subcarrier modulation

Sub-Channel Allocation Tx

Receive Diversity

November 2005


Slide 44

doc.: IEEE 802.22-05/0097r0

Submission

Simulation Results

November 2005


Slide 45

doc.: IEEE 802.22-05/0097r0

Submission

2K FFT OFDMA Optimized for 5MHz BW2K FFT OFDMA Optimized for 5MHz BW

-5 0 5 10 15 20 2510

-5

10-4

10-3

10-2

10-1

100

PER Vs. C/N on DL 2K (OFS) for ITU-B using 5MHz Channel with Phase-Noise

C/N

PE

R

QPSK 1/2 Div.X4 60KphQPSK 1/2 Div.X4 120KphQPSK 1/2 Div.X4 180KphQPSK 1/2 Div.X4 250KphQPSK 1/2 Div.X2 60KphQPSK 1/2 Div.X2 120KphQPSK 1/2 Div.X2 180KphQPSK 1/2 Div.X2 250Kph16QAM 1/2 60Kph16QAM 1/2 120Kph16QAM 1/2 180Kph16QAM 1/2 250Kph64QAM 1/2 60Kph64QAM 1/2 120Kph64QAM 1/2 180Kph64QAM 1/2 250Kph

November 2005


Slide 46

doc.: IEEE 802.22-05/0097r0

Submission

2K FFT OFDMA Optimized for 10MHz BW2K FFT OFDMA Optimized for 10MHz BW

-5 0 5 10 15 20 2510

-4

10-3

10-2

10-1

100

PER Vs. C/N on DL 2K (OFS) for ITU-B using 10MHz Channel with Phase-Noise

C/N

PE

R

QPSK 1/2 Div.X4 60KphQPSK 1/2 Div.X4 120KphQPSK 1/2 Div.X4 180KphQPSK 1/2 Div.X4 250KphQPSK 1/2 Div.X2 60KphQPSK 1/2 Div.X2 120KphQPSK 1/2 Div.X2 180KphQPSK 1/2 Div.X2 250Kph16QAM 1/2 60Kph16QAM 1/2 120Kph16QAM 1/2 180Kph16QAM 1/2 250Kph64QAM 1/2 60Kph64QAM 1/2 120Kph64QAM 1/2 180Kph64QAM 1/2 250Kph

November 2005


Slide 47

doc.: IEEE 802.22-05/0097r0

Submission

UL throughput measurement setup

Laptop

BST

LaptopEth

CPEEthHu

b

Laptop

Traffic Generator

Sniffer

packets

Att

Att

(Maximum throughput)

November 2005


Slide 48

doc.: IEEE 802.22-05/0097r0

Submission

UL Test Results

Modulation

Code rate

US PWR

REF

(dBm)

Expected results/

Measured results

GI =1/32

(Mbit/sec)

Expected results/

Measured results

GI =1/16

(Mbit/sec)

Expected results/

Measured results

GI =1/8

(Mbit/sec)

Expected results/

Measured results

GI =1/4

(Mbit/sec)

Expected

Delay

(Less than Msec)

QPSK 1/2 -20 4.1 4.72 3.9 4.6 3.7 3.6 3.4 3.4 29

QPSK 3/4 -20 7.0 7.25 6.6 6.9 6.4 6.2 5.8 6.0 29

16-QAM 1/2 -20 7.2 7.3 6.6 6.7 6.4 6.2 6.0 6.0 26

16-QAM 3/4 -20 11.4 11.7 11.4 11.5 10.6 10.2 9.0 9.2 26

64-QAM 1/2 -20 10.2 10.3 9.4 8.7 8.8 8.5 8.4 8.6 24

64-QAM 3/4 -20 TBD TBD TBD TBD TBD

November 2005


Slide 49

doc.: IEEE 802.22-05/0097r0

Submission

Laptop

BSTEth

CPEEthHu

b

Laptop

Sniffer for UL

UL packets

Laptop

Laptop

Hub

DL packets

Sniffer for DL

Traffic Generator For DL Traffic Generator For UL

Att

Att

PER tests set up (experimental equipment )

November 2005


Slide 50

doc.: IEEE 802.22-05/0097r0

Submission

UL PER test results

(Packet size=512 bytes, measurement time for each modulation 7 minutes)

GI=1/32 GI=1/16 GI=1/8 GI=1/4 Modulation

Code rate

US PWR

REF

(dBm)

(Mbit/sec)/

PER%

(Mbit/sec)/

PER%

(Mbit/sec)/

PER%

(Mbit/sec)/

PER%

4.72 4.65 3.6 3.4 QPSK 1/2 -20

0.01 0.01 0.01 0.007

7.25 6.9 6.2 5.8 QPSK 3/4 -20

0.3 1.2 1.0 0.005

6.7 6.7 6.2 6 16-QAM 1/2 -20

0.01 0.06 0.1 0.2

11.7 11.5 10.2 9.2 16-QAM 3/4 -20

0.5 0.07 0.2 0.4

8.9 8.7 8.5 8.65(1500byte)

64-QAM 1/2 -20

0.02 0.02 0.4 0.5

64-QAM 3/4 -20 TBD TBD TBD TBD

November 2005


Slide 51

doc.: IEEE 802.22-05/0097r0

Submission

CPE BST

SignalGeneratorInterferer

Att

PCPC

Combiner

DataInput

DataOutput

BPF

Att

BST receiver selectivity channel set up

Adjacent (Alternate) channel rejection

November 2005


Slide 52

doc.: IEEE 802.22-05/0097r0

Submission

Using a Reuse Factor of 1

By allocating different Sub-Channels to different sectors we can reach a reuse factor of 1 with up to 12 sectors (changing the polarity enhances the performance)

HorizontalSub-hannel

s Set 1F1

VerticalSub-hannel

s Set 1F1 V

ertic

alS

ub-h

anne

ls

Set

2F

1

Hor

izon

tal

Sub

-han

nel

s S

et 2

F1

November 2005


Slide 53

doc.: IEEE 802.22-05/0097r0

Submission

Coverage Patterns1 frequency, 2 frequencies

1 Frequency C/I = 2 - 10 dB

2 FrequenciesC/I = 10 -29 dB

November 2005


Slide 54

doc.: IEEE 802.22-05/0097r0

Submission

Coverage Patterns3 frequencies, 6 frequencies

3 Frequencies C/I = 18-30 dB

6 FrequenciesC/I = 22-30+ dB

November 2005


Slide 55

doc.: IEEE 802.22-05/0097r0

Submission

Applicable Spectrum mask (DVB-RCT, 2kFFT)

November 2005


Slide 56

doc.: IEEE 802.22-05/0097r0

Submission

Working with Different Interferers

Partial Band Jamming and Coexistence with IEEE802.11a, HiperLAN2 systems –

• Interference detection combined with smart ECC, enabling erasures on disturbed carriers

• The OFDMA (2k mode) has a 15dB “processing gain” against wide band Jammers or other 802.11a, HiperLAN2 interferers

carrier of largeFFT size

Power = P'

Frequency

carrier of smallFFT size

Power = P'

for the large sizeFFT we get

dBJammeraOFDMA

N

S1511.802

for the Small sizeFFT we get

dBJammerOFDMAa

N

S011.802

November 2005


Slide 57

doc.: IEEE 802.22-05/0097r0

Submission

Tuner

AGC-RF

SAW6MHz BW AMP

IF OUT

IF 36MHz

Freq InfoFrom WRAN

Modem

BPFLNA

NF=7dB

470-860MHz

From Processor

A/D10b

Demod.FFTTo Processor

To Analyze AndReport

Signal Signatures

WRAN Sensing scheme

• Scanning of +/- 8 channels from both sides of WRAN operating channel

• 50 steps of 2MHz each fed to the tuner

• Extracting signal signature within the scanned band will take 15 msec

November 2005


Slide 58

doc.: IEEE 802.22-05/0097r0

Submission

MAC ProposalMAC Proposal

November 2005


Slide 59

doc.: IEEE 802.22-05/0097r0

Submission

Proposal Outline

• Network Entry and Initialization– 802.16 based solutions

• Class of Services and Quality of Services– 802.16 based solutions

• Support for Interference Mitigation and Coexistence– New solutions proposed

• OA&M Support– To be defined

• Base Station and CPE Address Space– 802.16 based solutions

November 2005


Slide 60

doc.: IEEE 802.22-05/0097r0

Submission

Support for Interference Mitigation and Coexistence

• Protections of licensed incumbent services– RF Sensing Control– DFS Messaging Control

• LE systems coexistence and sharing– Spectrum sharing mechanism– Inter-system communications

November 2005


Slide 61

doc.: IEEE 802.22-05/0097r0

Submission

Protections of Licensed Incumbent Services

November 2005


Slide 62

doc.: IEEE 802.22-05/0097r0

Submission

RF Sensing Control

• Objectives– Licensed incumbent protection guarantee– 802.22 system QoS guarantee

• Possible Solutions– RF sensing separated with data transmissions– RF sensing overlapped with data transmissions

November 2005


Slide 63

doc.: IEEE 802.22-05/0097r0

Submission

RF Sensing in Quiet Periods

QuietSensing

R A Data TransmissionsQuiet

SensingR A

Sensing TimeChannel Detection Time (2000ms)

Data Transmissions

Measurement Reporting Frames

DFS Announcement Frames

Channel Move Grace Period (2000ms + 100ms)

Aggregate Control Tx Time (100ms)

time

periodgsen

DFSgsenData T

TTU

_sin

sin1

November 2005


Slide 64

doc.: IEEE 802.22-05/0097r0

Submission

RF Sensing in Quiet Periods

• Advantages– Reliable RF sensing

• Disadvantages– Data services interruption

• Transmission Latency

– Low system utilization• System throughput

November 2005


Slide 65

doc.: IEEE 802.22-05/0097r0

Submission

RF Sensing overlapped with Data Transmissions

• Proposal– Selective RF Sensing with simultaneous data

transmissions

• Properties– Continuous data transmissions– “Full” system utilization– RF sensing performed on selective spectrum

that reliable sensing can be achieved

November 2005


Slide 66

doc.: IEEE 802.22-05/0097r0

Submission

Selective RF Sensing

• Guard bands – guarantee reliable sensing

• Adaptive spectrum selection for RF sensing– Optimizing the sensing reliability and QoS

using intelligent control algorithms

Spectrum in useGuard band Spectrum being sensedSpectrum being sensed Guard band

Frequency

November 2005


Slide 67

doc.: IEEE 802.22-05/0097r0

Submission

Dynamic Frequency Hopping with Simultaneous Selective RF Sensing

Initial Sensing

Validation time of CH A

Transmitting on CH ASensing on CH ([0, A-n],

[A+n, N])

Less than Grace Period

Validation time of CH B


Transmitting on CH BSensing on CH ([0, B-n],

[B+n, N])

Time

• Validation time – The latest time a channel is validated to be vacant• Grace period – The maximum period of time a incumbent can tolerate interference for LE operations, from the beginning of the incumbent’s operations

November 2005


Slide 68

doc.: IEEE 802.22-05/0097r0

Submission

Frequency Hopping Collision


Operating on CH ASensing on CH ([0, A-n],

[A+n, N])

Validation time of CH C

Operating on CH CSensing on CH ([0, C-n],

[C+n, N])

Time

System A


Validation time of CH D

Operating on CH DSensing on CH ([0, D-n],

[D+n, N])


[C+n, N])

Time

System B

Validation time of CH C Collision on CH C

November 2005


Slide 69

doc.: IEEE 802.22-05/0097r0

Submission

DFH Collision Avoidance


Operating on CH ASensing on CH ([0, A-n],

[A+n, N])

Validation time of CH C

Operating on CH BSensing on CH ([0, B-n],

[B+n, N])

Time

System A


Validation time of CH D

Operating on CH DSensing on CH ([0, D-n],

[D+n, N])


[C+n, N])

Time

System B

Validation time of CH CAnnounce to use CH C

Collision free

November 2005


Slide 70

doc.: IEEE 802.22-05/0097r0

Submission

Start

Wait

DFSAnnouncement

FrequencySelection and

Acquisition

No conflictingannouncement

received?

Yes

Earlierannouncement

timestamp?

NoYes

No

Time out

No

Ready tohop to theselected

frequency

Yes

End

DFH/CAAlgorithm

November 2005


Slide 71

doc.: IEEE 802.22-05/0097r0

Submission

DFH/CA + Selective Sensing on Multiple Channels

Validation time of Ch A


Validation time of Ch B


TimeOperation Period of Ch A

Operation Period of Ch B

Validation time of Ch C

Operation Period of Ch C

November 2005


Slide 72

doc.: IEEE 802.22-05/0097r0

Submission

DFS Messaging Control

Report scheduling

Reporting

ACK & Re-scheduling

All CPEs reportedsuccessfully?

Maximum number ofretry exceeded?

No

NoDFS Announcing &Defective decision

adjustment

Yes

Yes

Sensing

InitialSensing

Start

November 2005


Slide 73

doc.: IEEE 802.22-05/0097r0

Submission

Spectrum Sensing Results

• Detect 4 channel conditions:1. Licensed incumbent occupied2. Another 802.22 system occupied3. Noisy4. Vacated/clean

• Sensing reports– Bit-vector and on-request raw data– Balancing efficiency and accuracy of sensing reports

• Validation time– For non-incumbent-occupied channels

November 2005


Slide 74

doc.: IEEE 802.22-05/0097r0

Submission

Report Scheduling• Polling

– BS polls CPEs to report through uplink (UL) MAP that schedules TX opportunities for CPE reporting

– the UL MAP may provide redundant transmission opportunities for CPE’s reporting

• Poll-me– CPE requests for reporting

• Contention – CPE requests for reporting or sends report via

contention opportunities (contention sub-channel/window)

November 2005


Slide 75

doc.: IEEE 802.22-05/0097r0

Submission

Report ACK and Re-scheduling

• Explicit report reschedule– The BS re-schedules those CPEs from which it

failed to receive the sensing reports in a subsequent UL MAP

• Implicit report acknowledgement– The BS ACKs the successful reports by not

scheduling in a subsequent UL MAP those CPEs from which it received their sensing reports

November 2005


Slide 76

doc.: IEEE 802.22-05/0097r0

Submission

DFS Decision• DFS decision-making

– The BS decides the valid channels to be used for the whole system in the next DFH period by summarizing all measurement reports

– Decisions could be made by as simple as logical ORs

• DFS decision announcement– DFS decision shall be announced to all CPEs in the

system, and to all neighbour BSs.

• Adjustment to prevent defective decisions– BS adjusts DFS decisions according to feedbacks from

CPEs and neighbour BSs

November 2005


Slide 77

doc.: IEEE 802.22-05/0097r0

Submission

Support for Interference Mitigation and Coexistence

• Protections of licensed incumbent services– RF Sensing Control– DFS Messaging Control

• LE systems coexistence and sharing– Spectrum sharing mechanism– Inter-system communications

November 2005


Slide 78

doc.: IEEE 802.22-05/0097r0

Submission

Co-existence of 802.22 Systems

• Objectives– Fair and efficient spectrum sharing mechanism

– Efficient inter-system communications for collaborative coexistence

• Proposals– On-demand Spectrum Contention

• Spectrum contention mechanism with integration of DFS and TPC

– Logical control connections• Over-the-air + over-the-backhaul

November 2005


Slide 79

doc.: IEEE 802.22-05/0097r0

Submission

Spectrum Sharing Mechanism – On-Demand Spectrum Contention

November 2005


Slide 80

doc.: IEEE 802.22-05/0097r0

Submission

Data Transmissions

Channel Evaluationand Selection

Sharing theselected channel

feasible?

No

Contention for owningthe selected channel

Selected channeloccupied by

802.22 systems?

Success ?

Transmissions withthe selected channel

Transmissions withoutthe selected channel

Yes

Yes

NoExternalDemand

InternalDemand

Yes

Initialization

On-DemandSpectrum Contention

No

November 2005


Slide 81

doc.: IEEE 802.22-05/0097r0

Submission

On-Demand SpectrumContention on Channel a

BS 2BS 3BS 1

Request/responses

via Control Channel

a

a

aSystem 3System 3System 3System 3System 3System 3System 3

System1System1System1System1System1System1System1

System2System2System2System2

Operation intervalOperation intervalOperation intervalOperation intervalOperation intervalOperation intervalOperation interval

Contention responseContention responseContention responseContention responseContention responseContention responseContention response

Contention requestContention requestContention requestContention requestContention requestContention requestContention request

c

b

Grace Period

November 2005


Slide 82

doc.: IEEE 802.22-05/0097r0

Submission

Properties of ODSC: Efficiency

• Low coexistence overhead – Coexistence overhead is only incurred on

demand (no constant O/H)– Low overhead inter-system communications that

are overlapping with data transmissions

• Low coexistence complexity – Simple contention mechanism – Distributed decision-making -- scalable

November 2005


Slide 83

doc.: IEEE 802.22-05/0097r0

Submission

Properties of ODSC: Adaptation

• Highly adaptive– Internal demand: channel conditions and

workload conditions – External demand: coexistence (spectrum

contention) requests

November 2005


Slide 84

doc.: IEEE 802.22-05/0097r0

Submission

Properties of ODSC: Fairness

• Contention based– Fair spectrum access for every system at any

moment

• Iterative process– Long-term global (multi-system) fairness

November 2005


Slide 85

doc.: IEEE 802.22-05/0097r0

Submission

Inter-System Communications – Logical Control Connections

November 2005


Slide 86

doc.: IEEE 802.22-05/0097r0

Submission

Logical Control Connections (LCC)

• Over-the-air logical control connection• Over-the-backhaul logical control connection

November 2005


Slide 87

doc.: IEEE 802.22-05/0097r0

Submission

Over-the-air Logical Control Connections

• Key Concepts– Bridge-CPE – Co-existence Connection, with Co-existence

Association– Over-the-air control connection = service

connection + coexistence connection

November 2005


Slide 88

doc.: IEEE 802.22-05/0097r0

Submission

Bridge CPE

• Located in the overlapping area of two cells

• Associated with one BS (service BS) through service connections;

• Associated with another BS (coexistence BS) through coexistence connections (for coexistence communications only)

Bridge CPE (associated with BS1)

Serviceconnections

Co-existenceconnection

BS0 BS1

November 2005


Slide 89

doc.: IEEE 802.22-05/0097r0

Submission

Co-existence Connections• Carry co-existence communications• Established and maintained

– Between a bridge CPE and the coexistence BS (C-BS) on request by the service BS (S-BS)

– Between two BSs (if S-BS is within the arrange of C-BS and S-BS behaves as a CPE of C-BS in such case)

– On channels occupied by the coexistence BS

• Establishment/maintenance performed along with service data transmission– Ranging, connection acquisition– Controlled by S-BS and shall be guaranteed that they are

not co-scheduled with service communications

November 2005


Slide 90

doc.: IEEE 802.22-05/0097r0

Submission

LCC Between Two Base Stations

Bridge CPE (associated with BS1)

Serviceconnections



BS0 BS1

November 2005


Slide 91

doc.: IEEE 802.22-05/0097r0

Submission

Over-the-Air Co-existence Communications via LCC

• S-BS communicates with C-BS for co-existence via B-CPE as a relay

– Communications via Service connection + coexistence connection

– S-BS controls the coexistence operations between B-CPE and C-BS

• Coexistence communications– Messaging for spectrum contention/negotiation, – Sensing measurement sharing, – Operation parameter announcement

November 2005


Slide 92

doc.: IEEE 802.22-05/0097r0

Submission

Coexistence Communications ControlService

BSBridgeCPE

CoexistBS

Data TX Scheduling Coexist TX Scheduling

(Ignored by Bridge CPE)

Coexist OperationScheduling Coexist TX Requests

Coexist TX Scheduling

Coexist Transmissions

Coexist TX Scheduling

(Ignored by Bridge CPE)

Data TX Scheduling

Scheduled Coexist Operation Period

Service Connections Coexist Connections

Data Transmissions

Data Transmissions

November 2005


Slide 93

doc.: IEEE 802.22-05/0097r0

Submission

Over-the-Backhaul LCC

CPE1

Serviceconnections

BS0 BS1

CPE0

Serviceconnections

Internet

November 2005


Slide 94

doc.: IEEE 802.22-05/0097r0

Submission

Co-existence Management Entity

802.22PHY

802.22MAC

SAP

MLME

IP

SAP

802.3 PHY

802.3 MAC

SAP

SAP

TCP/UDP

CoExistME

SAP

November 2005


Slide 95

doc.: IEEE 802.22-05/0097r0

Submission

Co-existence Management Messages

Respond2Get(MIBParams, SRC, DST);Get(MIBParams, SRC, DST);

Respond2Reqest(CoexistMesg, SRC, DST);Reqest(CoexistMesg, SRC, DST);

Respond2Set (MIBParams, SRC, DST);Set (MIBParams, SRC, DST);

Source CoexistME Destination CoexistME

Respond 2Get(MIBParams, SRC);Respond 2Get(MIBParams, DST);

Respond 2Request(CoexistMesg, SRC);Respond 2Reqest(CoexistMesg, DST);

Respond 2Set(MIBParams, SRC);Respond 2Set(MIBParams, DST);

Respond 2Set(MIBParams);

CoexistME MACMAC CoexistME

Get(MIBParams, SRC);Get(MIBParams, DST);

Request(CoexistMesg, SRC);Reqest(CoexistMesg, DST);

Set(MIBParams, SRC);Set(MIBParams, DST);

Set (MIBParams);

CoexistME MACMAC CoexistME

Destination Base StationSource Base Station

November 2005


Slide 96

doc.: IEEE 802.22-05/0097r0

Submission

Conclusion (MAC)

• Complete and efficient MAC solutions for interference mitigation and coexistence support

• Protections of licensed incumbent services– RF Sensing Control

– DFS Messaging Control

• LE systems coexistence and sharing– Spectrum sharing mechanism

– Inter-system communications

November 2005


Slide 97

doc.: IEEE 802.22-05/0097r0

Submission

Questions and Answers

doc.: ieee 802.22-05/0097r0 submission november 2005 eli sofer, runcom | wendong hu,...

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