doc.: ieee 802.22-06/0030r0 submission march 2006 huawei, nextwave, runcom, stmicroelectronicsslide...

March 2006

Huawei, NextWave, Runcom, STMicroelectronics

Slide 1

doc.: IEEE 802.22-06/0030r0

Submission

IEEE 802.22 WRAN Standard PHY/MAC Proposal IEEE P802.22 Wireless RANs Date: 2006-03-06

Name Company Address Phone email

Soo-Young Chang

Huawei 6000 J Street, Dept EEE, Sacramento, CA 95819-6019

1-916 278 6568 [email protected]

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

1-408-467-8410 [email protected]

Ramon Khalona

NextWave 2075 Las Palmas Dr Carlsbad, CA 92009

1-760-710-2063 rkhalona@nextwavetel

.com

Eli Sofer Runcom 2 Hachoma St. Rishon Lezion,

Israel

+972 544 997 996

[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].>

March 2006


Slide 2

doc.: IEEE 802.22-06/0030r0

Submission

Co-Authors

Name Company Address Phone email

Paul Piggin Cygnus

Jianwei Zhang Huawei

No. 98, Lane 91, Eshan Road, Pudong, Pudong Lujiazui Software Park,

Shanghai, China 200127

86-21-

6864480824638 [email protected]

Eli Plotnik Paragon Israel +972 542 332 255 [email protected]

Zion Hadad Runcom Israel +972544 560 655 [email protected]

Liwen ChuSTMicroelectronic

s

1060 E. Brokaw Rd.

San Jose, CA 95131

USA408-467-8436 [email protected]

Kyeongsoo Kim

STMicroelectronics

1060 E. Brokaw Rd.

San Jose, CA 95131, USA

408-451-8137 [email protected]

George Vlantis STMicroelectronic

s

1060 E. Brokaw Rd.

San Jose, CA 95131, USA

408-451-8109 [email protected]

March 2006


Slide 3

doc.: IEEE 802.22-06/0030r0

Submission

Abstract

In this presentation, we provide a technical overview of a full proposal for the Physical

(PHY) layer and the Medium Access Control (MAC) layer of the IEEE 802.22

Wireless Regional Networks (WRAN) Standard.

March 2006


Slide 4

doc.: IEEE 802.22-06/0030r0

Submission

PHY proposalPHY proposal

March 2006


Slide 5

doc.: IEEE 802.22-06/0030r0

Submission

What we have Proposed

Meeting Incumbents and SP`s Expectations

March 2006


Slide 6

doc.: IEEE 802.22-06/0030r0

Submission

OFDMA (Scalable FFT, 2k, 1k, 512) 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, 7 and 8 MHz channel BW or available separate TV

channels, optional use of 2 channels bonding • Power concentration (up to 15db) to boost selective sub-

channels to increase range• Efficient use of operator spectrum resources• Small data granularity (high statistical multiplexing gain)• Excellent reuse factor (close to 1)

High spectral efficiency in single/multi cell environment

Key design Considerations

March 2006


Slide 7

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Submission

• 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

• OFDMA supports advanced ranging based on identification of CDMA codes

• Extremely efficient BW-Request mechanism (90%, CDMA over OFDMA)

Extremely low network and user equipment prices

Key design Considerations

March 2006


Slide 8

doc.: IEEE 802.22-06/0030r0

Submission

System Parameters Parameters Specification Remark

Frequency range 54~862 MHz

System Capacity 75 Mbps (In a cell of 20 km radius) Satisfying user requirements

Based on typical deployment scenario using population density of 1.25 persons per 1 sq. km

Bandwidth• 6, 7, 8 MHz • 2 Channel bonding- Optional

• 3 or more separate TV channels instead of contiguous bonding• need change in FRD

Data rate• Maximum: 31.67 Mbps (64QAM,1/32) • Minimum: 5.03 Mbps (QPSK, ½)

Per 8 MHz channel

Spectral Efficiency• Maximum: 5.20 bits/s/Hz• Minimum: 0.74 bits/s/Hz

Apply to all bandwidth

Modulation QPSK, 16QAM, 64QAM On both Uplink and Downlink

Transmit power 4W EIRP per CPE According toFRD Requirement

Multiple Access Adaptive OFDMA on both Uplink and Downlink

FFT Mode 512, 1k and 2kModular Approach, reuse of the same modem in other available TV channels

Cyclic Prefix Mode 1/4, 1/8, 1/16, 1/32

Duplex TDD ( or FDD in the future)

Network topology p-to-mp

March 2006


Slide 9

doc.: IEEE 802.22-06/0030r0

Submission

1. System capacity versus range

• Minimum requirement for system capacity within a cell of 33km radius with density population of 1.25 persons/ sq. km versus 12 active users within the cell

2. Use of multiple TV channels may be useful (contiguous or not). (Note: 802 commented to the FCC that channel bonding SHOULD NOT be permitted to be persistent

Addressing inconsistencies in FRD

March 2006


Slide 10

doc.: IEEE 802.22-06/0030r0

Submission

• Spectrum availability

• Effects of narrowband jamming

• Scalability

• HW Complexity

• Unintentional Denial of service

• Reuse of the spectrum

• Computational Complexity

• deployment in Large cells

• Macro Diversity

Part 1

Part 2• OFDMA based Proposal

March 2006


Slide 11

doc.: IEEE 802.22-06/0030r0

Submission

Spectrum availability

Constraints on using 3channels bonding

• Three channels bonding is location dependant

• 3 channels bonding is not guaranteed in the future, incumbent services may expand (advent of HDTV), new regulatory scheme will admit new services. WIMAX Forum may succeed in migrating to UHF band and deployment in urban and semi-urban areas.

• In most cases, only partial use of the 3 channels bonding is possible

• SP`s should be assured of non interrupted service even within the constraints of WRAN deployment

March 2006


Slide 12

doc.: IEEE 802.22-06/0030r0

Submission

3 Contiguous TV channels

Jamming will affect only one channel that can be mitigated by elimination of sub-carriers affected and regrouping again of the sub-channels

Effects of narrow band Jamming

• jamming or narrowband interference will effect all sub-channels spread over the entire bandwidth. Will need regrouping of the remaining sub-carriers into new sub--channels

3 Separate TV Channels

March 2006


Slide 13

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Submission

Scalability

• Scalability is best served using Modular approach where the single channel attributes can be repeated in other available TV channels whether separate or contiguous . In other words, we recommend reuse of the same OFDMA modem on other available TV channels

• Economy of scale entails reuse of proven OFDMA modems to be shortly available meeting one of 16e profiles, such as WiBro, WiMAX )

• We have to realize that WRAN is operating on un-licensed band and as such there is no guarantee that 3 contiguous channels can be exploited most of the time

March 2006


Slide 14

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Submission

HW ComplexityBoth BS and CPE

• Need for highly expensive Linear PA in the BS for each sector in channels bonding scenario

• Not to exceed EIRP of 4W on each TV channel will need a computational process to ensure that power boosting or power concentration on some Sub-channels (spread on the entire 3 channels) will not exceed the 4W average limit. This may raise concern of incumbents.

• FRD does not support use of contiguous channel bonding on prolonged time

March 2006


Slide 15

doc.: IEEE 802.22-06/0030r0

Submission

Unintentional Denial of Service

• WRAN SP is expected to provide services on continual and fair basis, even with the use of one TV channel.

• SP should be capable of providing the needed capacity within his coverage area with the use of one TV channel and WRAN system should be deployed accordingly

• Users at the edge of the cells are therefore subject to an unintentional denial of service once one or two TV channels need to be vacated

March 2006


Slide 16

doc.: IEEE 802.22-06/0030r0

Submission

Reuse of the Spectrum

• Spectrum availability within the service area may not allow use of the 3 channels bonding or multiple TV channels

• WRAN Deployment will have to be based on reuse of the spectrum in adjacent cells within the coverage area and achieve reuse factor of 1

• Deployment in large cell to achieve range of 30km , in fact, negates SP business rationale

March 2006


Slide 17

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Submission

Computational Complexity

• Managing a large base of sub-channels

• Frequent need for regrouping of the sub-carriers in face of band shrinkage due to interference, jamming or in case of vacation of one or two TV channels

• Modular approach where separate TV channels can be exploited can eliminate computing complexity. Other advantage is use of proven design and implementation of several 16e profiles.

March 2006


Slide 18

doc.: IEEE 802.22-06/0030r0

Submission

Deployment in large cells

• 3 Channel bonding cannot satisfy capacity requirement in large cell (33 km radius), considering population density within the cell as referred to in FRD • From the standpoint of Service Provider it is imperative to offer continuous service with the needed capacity within the cell with the use of only one TV channel, user satisfaction is important, sustainable service is important• Exhausting energy to reach few users located on the edge of the cell who happened to need the service in the same time is not really appealing to SP`s. • Capacity will have the upper hand in the game of trade offs between capacity and range. Range can be extended using repeaters. • Our expectation is that WRAN will also be deployed in semi-urban areas where more populated areas are expected, hence more cell capacity is needed.

March 2006


Slide 19

doc.: IEEE 802.22-06/0030r0

Submission

Deployment in large cells

30 km radius

Simple Business Model for rural area• Cell size of 30km radius- 28,260 Sq Km

• Population density, 1.25 persons/sq km.

• Estimate number of Households and businesses within the service area is 12,000.

• Assume a Penetration rate of 30%, 8% of the subscribers are active in the same time. Peak data rate on DL is 1.5Mbps and average data rate on the DL is 400Kbps.

• Capacity needed on the DL (assuming 75% use of cell capacity) will be 150Mbps

Highly conservative estimate of

capacity needed is 150Mbps

March 2006


Slide 20

doc.: IEEE 802.22-06/0030r0

Submission

Proposed WRAN Base Station (6 Sectors Antenna Pattern)

• Use of antenna of 15 dBi gain

• Use of 3 separate TV channels

F1

F1F2

F2

F3

F3

• Offer better use of the spectrum,

• Low cost Linear PA for each sector,

March 2006


Slide 21

doc.: IEEE 802.22-06/0030r0

Submission

Base Station Antenna Pattern

Commercial antenna of 15 dBi gain in the operating frequency

March 2006


Slide 22

doc.: IEEE 802.22-06/0030r0

Submission

Low Interference Configuration

Macro Diversity

Path1

Path2

Low Power Transmission Less than 1W

WRANBS1

BS2

BS3

Array of three

separate antennas

Area 1

Area 2

HO

TV BS

Broadcast direction

Wireless Mic

March 2006


Slide 23

doc.: IEEE 802.22-06/0030r0

Submission

Part 2, Proposal Outline: PHY• Requirements & OFDMA basic Features• PHY preliminary proposal• Base-Band processing chain• Down-Link• Up-Link• Hybrid ARQ• Diversity Schemes• PAPR reduction• Simulation Results

March 2006


Slide 24

doc.: IEEE 802.22-06/0030r0

Submission

OFDMA basic features

March 2006


Slide 25

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 26

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 27

doc.: IEEE 802.22-06/0030r0

Submission

DownLink OFDMA Symbol (example)

Total Frequency BandGuard Band Guard Band

Symbol PilotsSub-Channel Data Carriers

March 2006


Slide 28

doc.: IEEE 802.22-06/0030r0

Submission

PHY preliminary proposal

March 2006


Slide 29

doc.: IEEE 802.22-06/0030r0

Submission

Duplexing Technique

• TDD

Multiple Access Method

• TDMA/OFDMA

OFDM Symbols allocated by TDMA

Sub-Carriers within an OFDM Symbol allocated by OFDMA

Diversity

• Frequency, Time, Code, Space

Basics

March 2006


Slide 30

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 31

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 32

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 33

doc.: IEEE 802.22-06/0030r0

Submission

Base-Band Processing Chain

March 2006


Slide 34

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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

March 2006


Slide 35

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 36

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 37

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Submission

Down-Link

March 2006


Slide 38

doc.: IEEE 802.22-06/0030r0

Submission

There are two basic modes of operation:

• Reuse smaller than 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

March 2006


Slide 39

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 40

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 41

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 42

doc.: IEEE 802.22-06/0030r0

Submission

DownLink Specification

March 2006


Slide 43

doc.: IEEE 802.22-06/0030r0

Submission

• FFT size : 2k, 1k and 512. • 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), for 2k

FFT• 32 Sub-Channels of 48 data carriers each (FUSC), for 2kFFT


March 2006


Slide 44

doc.: IEEE 802.22-06/0030r0

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


March 2006


Slide 45

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 46

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 47

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 48

doc.: IEEE 802.22-06/0030r0

Submission

Up-Link

March 2006


Slide 49

doc.: IEEE 802.22-06/0030r0

Submission

• FFT size : 2k, 1k and 512

• 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

March 2006


Slide 50

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 51

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 52

doc.: IEEE 802.22-06/0030r0

Submission

Up-Link CDMA on OFDMARanging and Bandwidth request

March 2006


Slide 53

doc.: IEEE 802.22-06/0030r0

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.


March 2006


Slide 54

doc.: IEEE 802.22-06/0030r0

Submission

Frequency band

1 2 3 30 31 32

block 1

12

3each group contains

53 carriers

• All usable carriers are divided into 32 carrier groups named basic group, each main group contains 53 basic groups.


March 2006


Slide 55

doc.: IEEE 802.22-06/0030r0

Submission

User #1

Total Frequency band

User #2

Guard Band Guard Band

0 5 521 222 10 1

User 1 = 0,5,2,10,4,20,8,17,16,11,9, 22 ,18,21,13,19,3,15,6,7,12,14,1User 2 = 2,10,4,20,8,17,16,11,9,22,18, 21 ,13,19,3,15,6,7,12,14,1,0,5

• Carriers are allocated by a basic series and it’s cyclic permutations for example:

• Basic Series:

0,5,2,10,4,20,8,17,16,11,9,22,18,21,13,19,3,15,6,7,12,14,1

• After two cyclic permutations we get:

2,10,4,20,8,17,16,11,9,22,18,21,13,19,3,15,6,7,12,14,1,0,5


March 2006


Slide 56

doc.: IEEE 802.22-06/0030r0

Submission

Ranging using CDMA like modulation

March 2006


Slide 57

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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

March 2006


Slide 58

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 59

doc.: IEEE 802.22-06/0030r0

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

Ranging Efficiency

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

March 2006


Slide 60

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Submission

Hybrid ARQ (HARQ)

March 2006


Slide 61

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 62

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 63

doc.: IEEE 802.22-06/0030r0

Submission

Diversity Schemes

March 2006


Slide 64

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 65

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 66

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 67

doc.: IEEE 802.22-06/0030r0

Submission

Power Amplifier Efficiency

PAPR Reduction

March 2006


Slide 68

doc.: IEEE 802.22-06/0030r0

Submission

• In the Up Stream due to Sub-Channel allocation (29 carriers from 1711 usable per OFDM symbol) a 17.7dB gain is achieved for one Sub-Channel allocation, an additional 1-2dB gain is achieved due to lower crest factor for the Upstream.

• Due to relatively high PAPR (8-10dB) a RF amplifier linearization technology will be used to minimize the need of power backoff from the RF amplifier

Combined A-XNN and OFDMA gives the optimal solution for WRAN


March 2006


Slide 69

doc.: IEEE 802.22-06/0030r0

Submission


PA RF Out

TwoBatteries

Conventional Power Supply

SingleBattery

RF In

RF Out

VEC

PA

March 2006


Slide 70

doc.: IEEE 802.22-06/0030r0

Submission

• Significantly higher efficiency - => longer talk-time;

• No need for higher supply voltage - • Double (or more) power output per transistor

=> Savings in Silicon “real estate”.


March 2006


Slide 71

doc.: IEEE 802.22-06/0030r0

Submission

• OFDMA-2048, 64-QAM PAR is 8.0dB @10-11

– requires 8.0dB backoff

• A-XNNR can reduce backoff to 3.5 - 4dB:

– Increases PA efficiency by >50%

– 100-200% more output power per transistor


March 2006


Slide 72

doc.: IEEE 802.22-06/0030r0

Submission

Simulation Results

March 2006


Slide 73

doc.: IEEE 802.22-06/0030r0

Submission

WRAN expected performance Illustrated Example

March 2006


Slide 74

doc.: IEEE 802.22-06/0030r0

Submission

• Subscriber Units at the Current OFDMA Symbol = 3

• Sub-Channels Allocated to Subscriber-Unit #1 = 12



• Number Of New Subscriber-Units Requesting Services = 3

All Subscriber Units Suffer Different Multi-Paths and different Attenuation's

WRAN expected performance

March 2006


Slide 75

doc.: IEEE 802.22-06/0030r0

Submission

• Constellation at the Base Station

WRAN expected Performance

March 2006


Slide 76

doc.: IEEE 802.22-06/0030r0

Submission

• Users Separation

WRAN expected Performance

March 2006


Slide 77

doc.: IEEE 802.22-06/0030r0

Submission

• User Estimation

-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

Constellation to Estiamte

-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

Estimated vec

WRAN Expected Performance - Results

March 2006


Slide 78

doc.: IEEE 802.22-06/0030r0

Submission

-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2


-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

Estimated vec

• User Estimation

WRAN expected Performance - Results

March 2006


Slide 79

doc.: IEEE 802.22-06/0030r0

Submission

-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2


-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

Estimated vec

• User Estimation

WRAN expected Performance - Results

March 2006


Slide 80

doc.: IEEE 802.22-06/0030r0

Submission

0 20 40 60 80 100 120 1400

50

100

150

200

250

300Despreading on All Users

• Finding New CPE`s-Units Requesting Services, Using the Ranging Pilots (CDMA/OFDM Techniques)

WRAN expected performance - Results

March 2006


Slide 81

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 82

doc.: IEEE 802.22-06/0030r0

Submission

Coverage Patterns1 frequency, 2 frequencies

1 Frequency C/I = 2 - 10 dB

2 FrequenciesC/I = 10 -29 dB

March 2006


Slide 83

doc.: IEEE 802.22-06/0030r0

Submission

Coverage Patterns3 frequencies, 6 frequencies

3 Frequencies C/I = 18-30 dB

6 FrequenciesC/I = 22-30+ dB

March 2006


Slide 84

doc.: IEEE 802.22-06/0030r0

Submission

Applicable Spectrum mask (DVB-RCT System) OFDMA based UpLink , 2kFFT

March 2006


Slide 85

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 86

doc.: IEEE 802.22-06/0030r0

Submission

RF Sensing ProposalRF Sensing Proposal

March 2006


Slide 87

doc.: IEEE 802.22-06/0030r0

Submission

BACKGROUND

• Spectrum usage of TV broadcast industries– the average TV market in the United States uses approximately 7 high-power channels of the

67 that it is allocated. This leaves an abundance of free channels that could be used for wireless access.

– With both the House and the Senate having recently passed bills requiring television broadcasts to switch from analog to digital sometime in early 2009, the 700-MHz band (channels 52 to 69) will be cleared of programming and moved to lower frequencies (channels 2 to 51). The 700-MHz band will be set aside for public-safety emergency transponders and for bidding by wireless networks.

in this proposal only channels 2 to 51 are considered.• Three possible ways suggested in one article to protect interference with incumbent

users– Listen-Before-Talk (LBT)– Geolocation/Database: GPS receivers installed in CPEs– Local beacon: locally transmitted signal used to identify incumbent users

Unused Digital TV Channels Could Increase U.S. Wireless Access, Federal action could allow unused channels at lower frequencies to be used for unlicensed wireless networks, Eric S. Crouch, Medill News Service, PC World, Saturday, November 19, 2005, http://www.washingtonpost.com/wp-dyn/content/article/2005/11/18/AR2005111800083_pf.html

March 2006


Slide 88

doc.: IEEE 802.22-06/0030r0

Submission

CHANNEL AVAILABILITY

• Questioned whether there will be significant channel availability for unlicensed use in major urban areas during the DTV transition.

– There is likely to be substantial channel availability during transition.– The issue of channel availability during the DTV transition is likely to be short-lived.– In rural areas, there is spectrum available now and there will be for the foreseeable future.

• Bill Rose’s email to 22 email reflector, Wed, November 23, 2005 10:05 am – “The analysis shows that even in congested markets like Dallas/Ft. Worth, 40 percent of the

TV channel spectrum will remain unused after America's DTV transition. In more rural markets like Juneau, Alaska, as much as 74 percent will be available.”

March 2006


Slide 89

doc.: IEEE 802.22-06/0030r0

Submission

TV CHANNELS IN U.S.

• Currently with 6 MHz bandwidth for each channel,– VHF low band: Chs 2-6 54-88 MHz

– VHF high band: Chs 7-13 174-216 MHz

– UHF band: Chs 14-69 470-806 MHz *

• After DTV transition,– VHF low band: Chs 2-6 54-88 MHz

– VHF high band: Chs 7-13 174-216 MHz

– UHF band: Chs 14-51 470-698 MHz *

• In this proposal, channels after DTV transition are considered.– Enough channels are expected to be maintained for WRAN.

• For other bandwidths – 7 and 8 MHz – the system concept can also be applied by changing system parameters.

* Ch 37 is reserved for radio astronomy

March 2006


Slide 90

doc.: IEEE 802.22-06/0030r0

Submission

SPECTRA OF TV CHANNELS

Analyzing the Signal Quality of NTSC and ATSC Television RF Signals.htm, Glen Kropuenske, Sencore

NTSC and DTV signal spectra

March 2006


Slide 91

doc.: IEEE 802.22-06/0030r0

Submission

NTSC TELEVISION BAND

Conventional Analog Television - An Introduction

March 2006


Slide 92

doc.: IEEE 802.22-06/0030r0

Submission

DTV PILOT FREQUENCY

Conventional Analog Television - An IntroductionPresented at the IEEE Broadcast Technical Society 49th Symposium September 24, 1999

Henry Fries and Brett JenkinsThales Broadcast & Multimedia, Inc.

Southwick, MA

March 2006


Slide 93

doc.: IEEE 802.22-06/0030r0

Submission

DTV SIGNAL VIEWED ON A SPECTRUM ANALYZER



Southwick, MA

March 2006


Slide 94

doc.: IEEE 802.22-06/0030r0

Submission

DTV OUT-OF-BAND“SHOULDERS”



Southwick, MA

March 2006


Slide 95

doc.: IEEE 802.22-06/0030r0

Submission

VSB TV PARAMETERS (1)

March 2006


Slide 96

doc.: IEEE 802.22-06/0030r0

Submission

VSB TV PARAMETERS (2)

March 2006


Slide 97

doc.: IEEE 802.22-06/0030r0

Submission

PROTECTION OF PART 74 DEVICES (1)

• Most microphones use analog modulation (FM)• Bandwidth:200 KHz• Power: max. 250 mW (24 dBm) in UHF band

– But usually operate at less than 50 mW– Ex. Power 10 mW, antenna gain -10 dBi, body absorption 27 dB, range 100 m, then

mim. received power level: -95 dBm• Required WRAN CPE out-of-band emission level to protect Part 74

devices: 6.2 uV/m (15.8 dBuV/m measured at 3 m in 120 KHz)• Path loss needed between microphone receiver and L-E devices beyond 1

m (required D/U = 20 dB)– High power WRAN devices (4 W): 129 dB– Low power L-E devices (100 mW): 113 dB

March 2006


Slide 98

doc.: IEEE 802.22-06/0030r0

Submission

PROTECTION OF PART 74 DEVICES (2)

• Mitigation techniques– Dynamic frequency selection (DFS)

• Sensing, detection, DFS network behavior to avoid hidden nodes• Practical sensing threshold: -107 dBm in 200 KHz• Max. sensing distance for

– Unfaded microphone: 8.7 Km (free space)– Faded (27 dB) microphone: 400 m (free space)

• Interference margin at edge of sensing contour for faded microphone:– High power WRAN devices (4W): -56.1 dB– Low power L-E devices (100 mW): -40.4 dB

March 2006


Slide 99

doc.: IEEE 802.22-06/0030r0

Submission

METHOD 1 (1) SENSING INCUMBENT SIGNALS

• TV band signal sensing for one channel band– Use only spectral components – not time domain components

• Less sensitive on other parameters used to design TV band tuners – for example, Phase noise, etc.

– Use FFT transform of received TV band signals at the receiver for only one TV band or a few bands• After wide band tuning and down converting or down converting and low pass filtering

– One example• BW=F=6 MHz for one band case• Sampling interval T=1/B=1/6 us, sampling rate=BW=6 MHz• Frequency resolution (or frequency separation) F0=3 KHz• Time period T0=1/F0=1/3 ms• Number of samples needed N0=T0/T= 2 KHz• Needs 2K point FFTs

March 2006


Slide 100

doc.: IEEE 802.22-06/0030r0

Submission


T00

t

T

F0

f

F0

Sense antenna

LNAcos2fptwhere fp: left edge freq. of the channel

LPF ADC FFT detector

Discrete Fourier Transform

Sense Receiver Structure

March 2006


Slide 101

doc.: IEEE 802.22-06/0030r0

Submission


• Sensing procedure for TV signals– Several to many frequency components taken in a 6 MHz band depending on the sensing

accuracy• for ex., F50, F103, F200, F417, and F1200

– Compare these values• Correlation method: compare the shape of spectrum of received signals

– Calculate correlations with pre-stored values for NTSC and DTV signals– If one of these values is larger than predetermined values, the judgment is that NTSC or DTV signal

exists.• Pilot detection method: check whether a pilot signal exists

– Calculate the ratio of pilot component to another component– If F417/F1200 > thn, this signal is NTSC– If F103/F1200 > thd, this signal is DTV

– Average frequency component values for several symbol periods to have better sensing results

March 2006


Slide 102

doc.: IEEE 802.22-06/0030r0

Submission


• Sensing procedure for wireless microphone signals– Two types of wireless microphone systems according to frequency usage

• Single frequency systems• Frequency agile systems

– Wireless systems should NOT be operated on the same frequency as a local TV station. • Only open (unoccupied) frequencies should be used. In the U.S., each major city has different local TV stations.

– Microphone signal detection procedure: sensing the spectral components using FFT devices• For ex., for every 3 KHz in a 6 MHz band a spectral component is measured and compared with other components: two comparison

methods used for DTC and NTSC signals can be applied• If considerable components in a 200 KHz band exist, a wireless microphone is considered to be operated in that band:

– For the previous case, if consecutive six components spaced equally in 200 KHz have considerable amount of energy, a microphone signal is detected.

• Or much correlation with stored microphone signals exists, a wireless microphone is considered to be operated in that band.

March 2006


Slide 103

doc.: IEEE 802.22-06/0030r0

Submission

METHOD 2 (1)

SENSING INCUMBENT SIGNALS

• After DTV transition in the U.S.,– VHF low band: Chs 2-6 54-88 MHz– VHF high band: Chs 7-13 174-216 MHz– UHF band: Chs 14-51 470-698 MHz *

• n consecutive bands in VHF High or UHF band selected for WRAN services– The whole band of n bands is divided into n*l subbands

• Each band has l subbands; each subband has 6000/l KHz bandwidth– At receiver, the received signal after down conversion is inputted to a l*n point FFT

• By comparing FFT output signals, currently operated incumbent users can be identified and categorized – NTSC, DTV, or Part 74 devices

• With this method all incumbent signal throughout the whole band (n TV bands) can be detected simultaneously

– Periodically all CPEs and BSs can do this sensing to update the list of active incumbent users

* Ch 37 is reserved for radio astronomy

March 2006


Slide 104

doc.: IEEE 802.22-06/0030r0

Submission


• NTSC signal sensing– After down conversion with (fp+1.25) MHz frequency shift, the received signal is inputted to

l*n point FFT devices– Compare the FFT outputs

• DTV signal sensing– After down conversion with (fp+0.30944) MHz frequency shift, the received signal is inputted

to l*n point FFT devices– Compare the FFT outputs

• Part 74 device sensing– After down conversion with fp MHz frequency shift, the received signal is inputted to l*n point

FFT devices– Compare the FFT outputs

• Various comparison methods can be considered– Correlation method or pilot detection method used in Method 1 is suggested for TV signals – If some consecutive strong components in 200 KHz exist, Part 74 device is considered to

operate in this band. Or correlation method will be applied for Part 74 device signals.

March 2006


Slide 105

doc.: IEEE 802.22-06/0030r0

Submission


• Select k consecutive bands out of n bands

f

Band 0 Band 1 Band k-1Selected bands

subband 0subband 1

subband 2

subband l-1

WRAN Incumbent user WRANWRAN/incumbent

March 2006


Slide 106

doc.: IEEE 802.22-06/0030r0

Submission

SPECTRAL CORRELATION (EXAMPLE)

8 measured spectral components

Using 8 measured components, a correlation is calculated.

March 2006


Slide 107

doc.: IEEE 802.22-06/0030r0

Submission

PROPOSED RECEIVER STRUCTURE

• At receiver, data receiving and incumbent signal sensing are executed simultaneously.

– Without having separate receiving and processing branches– Using sensing method 2– If more precise sensing is needed, sensing method 1 may be applied with an additional

signal processing block – needs one more ADC and FFT.

receive antenna

LNAcos2fptwhere fp: left edge freq. of the channel (or whole target band)

LPF ADC FFT

detector

demod

March 2006


Slide 108

doc.: IEEE 802.22-06/0030r0

Submission

ADVANTEGES OVER OTHER PROPOSED SCHEMES

• Advantage over energy detection including MRSS– At one measurement, all frequency components can be extracted: whole frequency

band can be covered for one FFT symbol duration : faster than MRSS which uses sweep oscillators.

– Correlation detection not energy detection: more intelligent sensing than MRSS

• Advantage over cyclostationary feature sensing– Can detect Part 74 device signals while cyclostationary sensors can not detect them

while NTSC and DTV signals can be detected relatively much easier than Part 74 signals.

• Advantage over other proposed schemes– Need not more hardware to sense: can use OFDM receiving blocks: only a detector

should be added for sensing– Faster and simpler than other proposed schemes

March 2006


Slide 109

doc.: IEEE 802.22-06/0030r0

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

Alternative 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

March 2006


Slide 110

doc.: IEEE 802.22-06/0030r0

Submission

MAC ProposalMAC Proposal

March 2006


Slide 111

doc.: IEEE 802.22-06/0030r0

Submission

MAC 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

March 2006


Slide 112

doc.: IEEE 802.22-06/0030r0

Submission

Support for Interference Mitigation and Coexistence

• Protections of licensed incumbent services– 802.22 Sensing Algorithm– RF Sensing and DFS Control– DFS Messaging Control

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

March 2006


Slide 113

doc.: IEEE 802.22-06/0030r0

Submission

Protections of Licensed Incumbent Services

March 2006


Slide 114

doc.: IEEE 802.22-06/0030r0

Submission

Tenets for Incumbent Protection• Whenever possible, make use of database

information containing channel availability information (location-dependent)

• Maintain a “candidate set” of available channels in case current channel needs to be vacated

• Periodically monitor channel (s) currently in use (i.e., “in service” monitoring)

• Sensing parameters (channel availability check time, etc.) to be optimized for agile service deployment

March 2006


Slide 115

doc.: IEEE 802.22-06/0030r0

Submission

Sharing Frequency Bands in 802.16

• Section 6.3.15 of the 802.16-2004 provides information on DFS

• Facilitates spectrum sharing in license-exempt spectrum• Provides for primary user detection and avoidance,

uniform spreading in the band of operation and TPC (tx power control)

• Primary users – defined by regulation to take priority in the band(s)

• Defining the use of aspects of DFS for ACS (Adaptive Channel Selection) for avoiding general other user or system interference.

March 2006


Slide 116

doc.: IEEE 802.22-06/0030r0

Submission

DFS in 802.16

Within 802.16-2004 (section 6.3.15) plus cor1 the DFS procedures, for detection of Primary User of the license-exempt bands, provide for the following:

• Testing channels for primary users• Discontinuing operations after detecting primary users• Detecting primary users• Scheduling for channel testing• Requesting and reporting of measurements• Selecting and advertising a new channel

March 2006


Slide 117

doc.: IEEE 802.22-06/0030r0

Submission

802.22 Sensing Algorithm

March 2006


Slide 118

doc.: IEEE 802.22-06/0030r0

Submission

Service initiation30 sec Channel

Availability Check on next channel

Available?

Choose a different channel

No

In service monitoring of operating channel

YesDetection above

threshold?**

No

Stop transmission

Yes

Select and change to new available* channel in 2 secs with ≤100 ms

transmission time

Channel unavailable for 10 minutes

Log of channel availability

* Available means the channel passes the channel availability check test

Start 10 minute timer

Available?

Yes

No

Background In Service Monitoring (on non-

operational channels)

Background 30 sec Channel Availability

Check

Begin operation on available* channel in 2

secs with ≤100 ms transmission time

** Detection is required within 2 secs of incumbent signal beginning operation

on the channel. Probability of detection ≥ 90%, false alarm rate of ≤ 10%

March 2006


Slide 119

doc.: IEEE 802.22-06/0030r0

Submission

RF Sensing and DFS Control

March 2006


Slide 120

doc.: IEEE 802.22-06/0030r0

Submission

RF Sensing and DFS Control

• Objectives– Licensed incumbent protection guarantee– QoS Satisfactory for 802.22 systems

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

March 2006


Slide 121

doc.: IEEE 802.22-06/0030r0

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

periodsense

DFSsensesystem T

TTU

_

1

March 2006


Slide 122

doc.: IEEE 802.22-06/0030r0

Submission

Quiet Period RF Sensing and DFS

ChannelAvailability Check

75ms

QS

DataTransmiss

ion

QS

DataTransmiss

ion

2 seconds<2s

ChannelSetup

> 30 seconds

…...Data

Transmission

QS

2 seconds<2s

ChannelMove

ChannelNon-occupancy

Time

QS

DataTransmiss

ion

QS

DataTransmiss

ion…...Channel Availability Check - Backup channel (list)

<2sChannel

Setup

Ch X

Ch Yand/orCh Z

March 2006


Slide 123

doc.: IEEE 802.22-06/0030r0

Submission

RF Sensing Control in Quiet Periods

• Advantages– Reliable RF sensing (no self-interference)

• Disadvantages– Data services interruption

• Transmission Latency

– Potential low system utilization• System throughput

periodsense

DFSsensesystem T

TTU

_

1

March 2006


Slide 124

doc.: IEEE 802.22-06/0030r0

Submission

Simultaneous Selective RF Sensing

• Proposed Solution for RF Sensing Control– Selective RF Sensing with simultaneous data

transmissions

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

that reliable sensing can be achieved

March 2006


Slide 125

doc.: IEEE 802.22-06/0030r0

Submission

Selective RF Sensing

• Guard bands – guarantee reliable sensing– Variable, depending on sensing techniques, tx power, incumbent, etc.

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

algorithms

– Band to sense, number of channels to sense

Spectrum in useGuard band Spectrum being sensedSpectrum being sensed Guard band

Frequency

March 2006


Slide 126

doc.: IEEE 802.22-06/0030r0

Submission

Selective RF Sensing• Provide flexibility of strategic channel selection for

RF sensing, optimizing:– RF sensing performance

– QoS of 802.22 systems

• Flexibility of channel selection– Channels to be sensed

• Channels with less probability of incumbent occupancy

– Number of channels to be sensed

– Size of the Guard band• Positive, negative, infinite

March 2006


Slide 127

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 128

doc.: IEEE 802.22-06/0030r0

Submission

Dynamic Frequency Hopping

• A 802.22 system cognitively and continuously switches operation frequencies for data transmissions.

• Both frequency selections and the length of an operation period on a channel are determined dynamically in runtime by a cognitive engine.

• A 802.22 system transmits data on a frequency for an operation period (DFH Operation Period) whose length is varied and shall not exceed the grace period.

March 2006


Slide 129

doc.: IEEE 802.22-06/0030r0

Submission

Dynamic Frequency Hopping

• A 802.22 system performs both data transmissions on a channel, say Channel A, and RF sensing on channels [0, A-n] and channel [A+n, N] in each operation period– Channel “0” and Channel “N”

• Lower bound and upper bound of the sensing spectrum

– “n” is the number of channels in the guard band

March 2006


Slide 130

doc.: IEEE 802.22-06/0030r0

Submission

DFH Operation Cycle

• During a DFH operation cycle– BS schedules the system to switch (hop) to channel (set) A

– BS and CPEs perform data transmissions on channel (set) A

– BS performs, and schedules CPEs to perform spectrum sensing on channel [0, A-n] and [A+n, N]

– CPEs report sensing measurement results

– BS performs report processing

– BS performs channel selection and acquisition

– BS announces DFS decision for the next operation cycle

March 2006


Slide 131

doc.: IEEE 802.22-06/0030r0

Submission

Comparing DFH with Quiet Sensing

Quiet Sensing Control


75ms

QS

DataTransmiss

ion

QS

DataTransmiss

ion

2 seconds<2s

ChannelSetup

> 30 seconds

…...Data

Transmission

QS

2 seconds<2s

ChannelMove


Time

QS

DataTransmiss

ion

QS

DataTransmiss

ion…...Channel Availability Check - Backup channel (list)

<2sChannel

Setup

Ch X

Ch Yand/orCh Z

March 2006


Slide 132

doc.: IEEE 802.22-06/0030r0

Submission



<2sChannel

Setup > 30 seconds

Ch X

Channel Availability CheckCh Y

Channel SensingTransmission

& ChannelMaintenance

Channel Sensing

2 seconds<2s

ChannelSetup

Channel Sensing

Ch Z Channel Availability Check Channel Sensing

2 seconds

ChannelSensing

ChannelSensing


Time

Transmission& Channel

Maintenance


Maintenance


Maintenance

…...

…...

<2sChannel

Setup

Sensing Control with DFH

March 2006


Slide 133

doc.: IEEE 802.22-06/0030r0

Submission


• Advantages of CFH– Avoid lengthy Quiet Periods (75ms per 2

seconds)– Avoid frequency switching overheads:

• Channel Move overhead (up to 2 seconds)

• Channel Setup overhead (up to 2 seconds)

March 2006


Slide 134

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 135

doc.: IEEE 802.22-06/0030r0

Submission

Collision Avoidance for Channel Switching

• Resolve “hidden node” problem for channel switching

• Cognitive Frequency Hopping/Collision Avoidance (CFH/CA) algorithm

• Announce CFH decisions to neighbor 802.22 systems

• Wait for conflicting announcements• Perform CFH when switching collision is guaranteed

to be avoided.

March 2006


Slide 136

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 137

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 138

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 139

doc.: IEEE 802.22-06/0030r0

Submission

Key Advantages of DFH with Selective Sensing

• Reliable RF Sensing Performance – Selective sensing with Sufficient sensing time

– Support sensing of large number of channels w/o QoS concerns

• Timely Licensed Incumbent Protection– Fulfill timing requirements imposed by incumbents

• QoS Satisfactory for License Exempt Systems – Latency

• Avoid sensing latency required by quiet sensing schemes

– Throughput• Avoid sensing overhead required by quiet sensing schemes

March 2006


Slide 140

doc.: IEEE 802.22-06/0030r0

Submission


• Low Implementation Cost – Future-proof

• Tolerable to more restricted sensing requirements in the future

– Sensing techniques insensitive• Allow longer sensing time from simple sensing techniques

– DFS messaging algorithms insensitive• Allow longer DFS messaging time from simple DFS

messaging algorithms

– Marginal hardware cost increase

• Only need a simple 2nd receiver for simultaneous RF sensing.

March 2006


Slide 141

doc.: IEEE 802.22-06/0030r0

Submission


• Flexible Framework for RF Sensing Control and DFS control– Cognitive Frequency Hopping Modes – Quiet Sensing Mode– Multiple-channel Operation

March 2006


Slide 142

doc.: IEEE 802.22-06/0030r0

Submission

DFS Messaging Control

March 2006


Slide 143

doc.: IEEE 802.22-06/0030r0

Submission


• DFS Messaging Algorithm

• DFS Messages

• PHY Supports– 1uS resolution monitoring

– Accurate threshold setting for detection

– Sub-frame frequency agility (for monitoring)

March 2006


Slide 144

doc.: IEEE 802.22-06/0030r0

Submission


• Key Advantages– Reliable, efficient, and flexible mechanism for

channel measurement reporting and DFS announcements

– Sufficient messaging time guaranteed without affecting data transmission QoS such as latency and throughput• Simultaneously performed DFS messaging

Algorithm

March 2006


Slide 145

doc.: IEEE 802.22-06/0030r0

Submission

DFS Messaging Algorithm

Report scheduling

Reporting

ACK & Re-scheduling

All CPEs reportedsuccessfully?

Maximum number ofretry exceeded?

No

NoDFS Announcing &Defective decision

adjustment

Yes

Yes

Sensing

InitialSensing

Start

March 2006


Slide 146

doc.: IEEE 802.22-06/0030r0

Submission

Contents of Spectrum Sensing Results

• Detect at least 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

March 2006


Slide 147

doc.: IEEE 802.22-06/0030r0

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, 1-bit flag in BW request PDU

• Contention – CPE requests for reporting or sends report via contention

opportunities (contention sub-channel/window)

March 2006


Slide 148

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 149

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 150

doc.: IEEE 802.22-06/0030r0

Submission

MAC Messages for DFS

• MAC messages is already available in the 802.16• MAC message is in section: 6.3.2.3.33 Channel

measurement Report Request/Response (REP-REQ/RSP) (802.16-2004+cor1)

• TLVs (which form the content of the MAC message are at: 11.12 REP-RSP management message encodings)– See the next slide

March 2006


Slide 151

doc.: IEEE 802.22-06/0030r0

Submission

MAC Messages for DFS: TLVs

March 2006


Slide 152

doc.: IEEE 802.22-06/0030r0

Submission

Detection Scenario and MAC messaging

Tx

Rx

BS

Tx

Rx

CPE

DFS

DCD(Ch number)

Tx

Rx

BS

Tx

Rx

CPE

DFS

REP-RSP(bit2=1) Unsolicited

UCD(Ch number)

March 2006


Slide 153

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 154

doc.: IEEE 802.22-06/0030r0

Submission

Co-existence of 802.22 Systems

March 2006


Slide 155

doc.: IEEE 802.22-06/0030r0

Submission

Co-existence of 802.22 Systems

• Objectives– Fair and efficient spectrum sharing mechanism– Efficient inter-system communications for

collaborative coexistence

• Proposed Techniques– On-demand Spectrum Contention

• Spectrum contention mechanism with integration of DFS and TPC

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

March 2006


Slide 156

doc.: IEEE 802.22-06/0030r0

Submission

Spectrum Sharing Mechanism – On-Demand Spectrum Contention

(ODSC)

March 2006


Slide 157

doc.: IEEE 802.22-06/0030r0

Submission

Key Properties of ODSC

• Integrate dynamic frequency selection (DFS) and transmission power control (TPC) with dynamic spectrum contentions

• Provides fairness, efficiency and adaptivity of spectrum access using active inter-system coordination

March 2006


Slide 158

doc.: IEEE 802.22-06/0030r0

Submission


• Efficiency– Low coexistence overhead

• Coexistence overhead is only incurred on demand – No constant overhead

• Low overhead inter-system communications that are overlapped with data transmissions

– Low complexity• Simple contention mechanism

– No complex coordination mechanism that is usually required for TDMA-based solutions

• Distributed decision-making -- scalable

March 2006


Slide 159

doc.: IEEE 802.22-06/0030r0

Submission


• Fairness

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

moment

• Local fairness

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

March 2006


Slide 160

doc.: IEEE 802.22-06/0030r0

Submission


• Adaptivity– Highly adaptive to operation demands

• Internal demand: channel conditions and workload conditions

• External demand: coexistence (spectrum contention) requests

March 2006


Slide 161

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 162

doc.: IEEE 802.22-06/0030r0

Submission

On-Demand Spectrum Contention (ODSC) Algorithm

• Channel Evaluation and Selection– Select spectrum holes (available channels) – Operations:

• RF sensing

• Measurement (sensing results) evaluations

• Measurement reporting

• Report processing• Frequency selection

March 2006


Slide 163

doc.: IEEE 802.22-06/0030r0

Submission


• Verifying the Feasibility of Non-Exclusive Channel Sharing– Channel sharing through transmission power control

(TPC) such that 802.22 systems sharing the same channel do not cause harmful interference to one another

– Non-exclusive spectrum sharing method is feasible as long as the maximum achievable signal-to-interference-ratio (SIR) on the selected channel is higher than the required SIR of the 802.22 for the supported services

March 2006


Slide 164

doc.: IEEE 802.22-06/0030r0

Submission


• Channel Contention for Exclusive Channel Sharing – Facilitated by Inter-System Coordination through

explicit contention messaging

– Basic contention components• Contention requests

• Contention resolution

• Contention responses

– Contention messaging through inter-system control connections

March 2006


Slide 165

doc.: IEEE 802.22-06/0030r0

Submission


• Operations if Non-Exclusive Channel Sharing feasible– The 802.22 system acquiring the channel

schedules data transmissions on the channel with proper transmission parameters (such as transmission power)

– Collision avoidance of channel switching shall be applied

March 2006


Slide 166

doc.: IEEE 802.22-06/0030r0

Submission


• Operations after Channel Contentions for Exclusive Channel Sharing– The 802.22 system acquiring the channel, if won,

• Schedules data transmissions on the channel starting from the time agreed upon by both contending systems

– After a Grace Period starting from the point of contention resolution

• Collision avoidance of channel switching shall be applied

– The 802.22 system using the channel, if lost,• Releases the channel starting from the time agreed upon by

both contending systems (after a Grace Period)

March 2006


Slide 167

doc.: IEEE 802.22-06/0030r0

Submission


• Iterative Spectrum Sharing Processes Initiated On-Demands – Internal Demands

• Initiated by a WRAN itself

• To Fulfill the internal QoS requirements of a 802.22 system• Based upon the following dynamic conditions

– Channel condition

– Workload condition

– External Demands• Coexistence requests from other 802.22 systems

March 2006


Slide 168

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 169

doc.: IEEE 802.22-06/0030r0

Submission

Dynamic Frequency Hopping Together with On-Demand Spectrum Contention

WRAN0 WRAN1

WRAN 0 Normal Operation

Idle Normal Operation

Idle

WRAN 1

Normal Operation

Idle

Vertical Sharing withIncumbents (DFH)

Horizontal Sharing amongWRANs with ODSC

Interruption Interval

Grace period

March 2006


Slide 170

doc.: IEEE 802.22-06/0030r0

Submission

Evaluations of ODSC• Evaluating the Feasibility, Fairness, and Efficiency of the proposed

spectrum sharing mechanism (ODSC)• Simulation Methodology

– Tool• Network Simulator (NS2: http://www.isi.edu/nsnam/ns/ )

– Evaluation Metrics• Channel Occupation Time (Throughput);• Service Interruption Time (Minimum Service Delay)

• Simulation Scenarios– 10 Coexistence Scenarios are evaluated;– Simulation Parameters

• Simulation Time: 6000 seconds• Channel check period: 1ms• Channel release grace period: 10ms• Single-channel operation

March 2006


Slide 171

doc.: IEEE 802.22-06/0030r0

Submission

Scenario #1

WRAN0 WRAN1

Total ChannelOccupation Time

Total ServiceInterruption Time

Number of ServiceInterruptions

Maximum ServiceInterruptin Time

Average ServiceInterruption Time

WRAN 0 2999.774802 3000.224998 249981 0.032000 0.012002

WRAN 1 3000.174002 2999.825698 249981 0.032000 0.012000

Single channel sharing

March 2006


Slide 172

doc.: IEEE 802.22-06/0030r0

Submission

Scenario #2

WRAN0 WRAN1

WRAN2






WRAN 0 2000.492015 3999.507785 181850 0.137000 0.0219934

WRAN 1 2001.196509 3998.803191 181907 0.135000 0.0219827

WRAN 2 1998.255730 4001.743870 181698 0.145000 0.0220241


March 2006


Slide 173

doc.: IEEE 802.22-06/0030r0

Submission

Scenario #3

WRAN0 WRAN2

WRAN3

WRAN1






WRAN 0 1503.2030057 4496.7967943 140944 0.2240001 0.0319048

WRAN 1 1497.9426565 4502.0570435 140433 0.2330001 0.0320584

WRAN 2 1501.0699270 4498.9296730 140731 0.2260001 0.0319683

WRAN 3 1497.7269596 4502.2725404 140405 0.2570001 0.0320663


March 2006


Slide 174

doc.: IEEE 802.22-06/0030r0

Submission

Scenario #4

WRAN0 WRAN1

WRAN2






WRAN 0 2996.0080237 3003.9917763 261763 0.0190001 0.0114760

WRAN 1 2996.8639237 3003.1357763 261763 0.0180001 0.0114727

WRAN 2 2966.8684238 3033.1311762 261762 0.0190001 0.0115874


March 2006


Slide 175

doc.: IEEE 802.22-06/0030r0

Submission

Scenario #5

WRAN0 WRAN2

WRAN3

WRAN3






WRAN 0 2964.2673193 3035.7324807 264806 0.0160001 0.0114640

WRAN 1 2963.7925194 3036.2071806 264806 0.0170001 0.0114658

WRAN 2 2963.8401193 3036.1594807 264806 0.0160001 0.0114656

WRAN 3 2964.3003194 3035.6991806 264806 0.0160001 0.0114639


March 2006


Slide 176

doc.: IEEE 802.22-06/0030r0

Submission

Scenario #6

WRAN0 WRAN2

WRAN3

WRAN1






WRAN 0 2339.0349329 3660.9648671 211672 0.2000001 0.0172855

WRAN 1 1793.2094443 4206.7902557 162556 0.7620001 0.0258790

WRAN 2 2339.9367243 3660.0628757 211758 0.2000001 0.0172842

WRAN 3 1794.3465324 4205.6529676 162678 0.5570001 0.0258526


March 2006


Slide 177

doc.: IEEE 802.22-06/0030r0

Submission

Scenario #7

WRAN0 WRAN1





Average Service Interruption Time

WRAN 0 5999.9987999 0.0010001 1 0.0010001 0.0010001

WRAN 1 5999.9986999 0.0010001 1 0.0010001 0.0010001

Double channel sharing

March 2006


Slide 178

doc.: IEEE 802.22-06/0030r0

Submission

Scenario #8

WRAN0 WRAN1

WRAN2






WRAN 0 4003.1941604 1996.8056396 166396 0.0380001 0.0120003

WRAN 1 3997.2624129 2002.7372871 166872 0.0290001 0.0120016

WRAN 2 3999.4909345 2000.5086655 166655 0.0310001 0.0120039


March 2006


Slide 179

doc.: IEEE 802.22-06/0030r0

Submission

Scenario #9

WRAN0 WRAN2

WRAN3

WRAN1






WRAN 0 2992.2231393 3000.7766607 136606 0.1430001 0.0219667

WRAN 1 2999.8890727 3000.1106273 136272 0.1260001 0.0220156

WRAN 2 3004.0164858 2995.9831142 136144 0.1370001 0.0220060

WRAN 3 2996.8142596 3003.1852404 136406 0.1370001 0.0220165


March 2006


Slide 180

doc.: IEEE 802.22-06/0030r0

Submission

Scenario 10

WRAN0

WRAN2

WRAN3 WRAN1

WRAN4

WRAN5

WRAN6

Total Channel Occupation Time

Total Service Interruption Time

Number of Service Interruptions

Average Service Interruption Time

Standard Variation of Interruption Time

WRAN 0 19.82911 40.18088 1978 0.02030 0.00000444

WRAN 1 20.01184 39.98785 1995 0.02004 0.00000470

WRAN 2 20.00967 39.98992 1997 0.02002 0.00000508

WRAN 3 20.01869 39.98080 1996 0.02003 0.00000463

WRAN 4 20.05857 39.94082 1999 0.01998 0.00000429

WRAN 5 19.96658 40.03271 1992 0.02009 0.00000574

WRAN 6 20.05442 39.94477 1998 0.01999 0.00000513

March 2006


Slide 181

doc.: IEEE 802.22-06/0030r0

Submission

Simulation Results Summary

Comparisons of Scenarios

0

0.2

0.4

0.6

0.8

1

1.2

SC7 SC8 SC9 SC5 SC1 SC2 SC3 SC4(favor) SC4(unfavor) SC6(favor) SC6(unfavor)

Scenarios

Cha

nnel

Occ

upat

ion

Tim

e (%

)

0

5

10

15

20

25

30

35

Ser

vice

Inte

rrup

tion

Tim

e (m

s)

Channel Occupation Time

Service Interruption Time

March 2006


Slide 182

doc.: IEEE 802.22-06/0030r0

Submission

Inter-System Communications – Logical Control Connections

March 2006


Slide 183

doc.: IEEE 802.22-06/0030r0

Submission

Logical Control Connections (LCC)

• Connection based inter-BS communications– Reliable, efficient

• Enable the feasibility and overall efficiency of the collaborative coexistence mechanism

• Established and maintained both over the air and over the backhaul

March 2006


Slide 184

doc.: IEEE 802.22-06/0030r0

Submission

Logical Control Connections (LCC)

• Very low communications overhead incurred in terms of – Spectrum bandwidth– Messaging latency– Hardware/software complexities

March 2006


Slide 185

doc.: IEEE 802.22-06/0030r0

Submission

Over-the-air Logical Control Connections

• Key Concepts– Bridge-CPE – Co-existence Connection– Co-existence Association– Over-the-air control connection

• Service connection + coexistence connection

March 2006


Slide 186

doc.: IEEE 802.22-06/0030r0

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 – Coexistence communications

only

BS0 BS1

CPE0

CPE1CPE2

Service connections Coexist connections

March 2006


Slide 187

doc.: IEEE 802.22-06/0030r0

Submission

Co-existence Connections• Regular connections

– Carry co-existence communications only

• 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

• S-BS behaves as a CPE of C-BS in such case)

– On channels occupied by the coexistence BS

March 2006


Slide 188

doc.: IEEE 802.22-06/0030r0

Submission

Co-existence Connections

• Establishments/maintenances are 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

March 2006


Slide 189

doc.: IEEE 802.22-06/0030r0

Submission

LCC Between Two Base Stations

Bridge CPE (associated with BS1)

Serviceconnections

Co-existenceconnection

Co-existenceconnection

BS0 BS1

March 2006


Slide 190

doc.: IEEE 802.22-06/0030r0

Submission

Over-the-Air Co-existence Communications

• 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 (transmission power, channel in-use, etc.)

announcement

March 2006


Slide 191

doc.: IEEE 802.22-06/0030r0

Submission

Coexistence Communications Control

ServiceBS

BridgeCPE

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

S-BS controls the coexistence communications (operations) between B-CPE and C-BS

March 2006


Slide 192

doc.: IEEE 802.22-06/0030r0

Submission

Over-the-Backhaul Logical Control Connections

CPE1

Serviceconnections

BS0 BS1

CPE0

Serviceconnections

Internet

Used to establish and maintain inter-system communications when Over-the-air communications is not feasible.

March 2006


Slide 193

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 194

doc.: IEEE 802.22-06/0030r0

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

March 2006


Slide 195

doc.: IEEE 802.22-06/0030r0

Submission

Conclusion (MAC)• Complete, efficient, and flexible MAC solutions for

interference mitigation and coexistence support• Protections of licensed incumbent services

– Sensing Algorithm based on Database and RF Sensing– RF Sensing Control: Selective Simultaneous RF Sensing– DFS Control: Dynamic Frequency Hopping– DFS Messaging Control based on 802.16 MAC Messages

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

March 2006


Slide 196

doc.: IEEE 802.22-06/0030r0

Submission

Questions and Answers

doc.: ieee 802.22-06/0030r0 submission march 2006 huawei, nextwave, runcom, stmicroelectronicsslide...

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