c80216m-09_0015.ppt

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Bandwidth Request ChannelIEEE 802.16 Presentation Submission Template (Rev. 9)Document Number:

C80216m-09/0015Date Submitted:

2009-01-05Source:

Sungho Park ([email protected])Jinyoung Chun ([email protected])Bin-Chul Ihm ([email protected])LG Electronics*<http://standards.ieee.org/faqs/affiliationFAQ.html>

Re:“802.16m SDD text”: IEEE 802.16m-08/052, “Call for Comments on Project 802.16m System Description Document (SDD)” Target topic: 11.9 UL Control Structure

Base Contribution:None

Purpose:Discussion and adoption for 802.16m SDD

Notice:This document does not represent the agreed views of the IEEE 802.16 Working Group or any of its subgroups . It represents only the views of the participants listed in the “Source(s)” field above. It is offered as a basis for discussion. It is not binding on the contributor(s), who 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 802.16.

Patent Policy:The contributor is familiar with the IEEE-SA Patent Policy and Procedures:

<http://standards.ieee.org/guides/bylaws/sect6-7.html#6> and <http://standards.ieee.org/guides/opman/sect6.html#6.3>.Further information is located at <http://standards.ieee.org/board/pat/pat-material.html> and <http://standards.ieee.org/board/pat >.

http://standards.ieee.org/faqs/affiliationFAQ.html

http://standards.ieee.org/faqs/affiliationFAQ.html

http://standards.ieee.org/guides/bylaws/sect6-7

2/25

Contents• Bandwidth Request Procedure

– Basic 3-step quick procedure– 5-step procedure as fallback mode of 3-step procedure

• Bandwidth Request Channel Structure– Green Field– Legacy Support

• Simulation Results– Parameters– Link performances

• Proposed Text

• Appendix– Simulation Method– Performance Metric for Indicator– Performance Metric for Message– BR Rate

3/25

Fail

Bandwidth Request Procedure

Preamble only detection & message error

Preamble detection & message detection

DL UL DL UL DL UL DL UL DL UL DL UL

1 2 3 4 5

Transmits BW-REQ with preamble and message

UL grant after BW-REQ message

- Grant type 1- Rx info: Rx location, code,

partial MS_ID, etc.- Resource allocation info. for

data transmission

1

2

UL grant after BW-REQ preamble- Grant type 2- Rx info: Rx location, code- Resource allocation info. for MAC BW-REQ message

(ex. Non-contention BR, BR header)

Try BW-REQ after back-off time

UL data transmission with Full MS_ID or additional BW-REQ

3

MAC BW-REQ message- Full MS_ID, Flow_ID, Buffer size, etc

UL grant after MAC BW-REQ message- Grant type 3- Full MS_ID, Buffer size, etc- Resource allocation info. for data transmission

2

3

4

5 UL data transmission w/ or w/o additional BW-REQ

<3-step procedure>

<5-step procedure>

4/25

Bandwidth Request Channel Structure• Green Field

– Bandwidth Request Channel• A BW-REQ channel consists of 3 distributed BW-

REQ tiles.• A BW-REQ tile is defined as 6 contiguous

subcarriers by 6 OFDM symbols.

– Preamble• It can include indicator to notice the ABS of a UL

grant request.• Allocation

– CDM based multiplexing with orthogonal sequence of length 12

– Dimension : 2x6 (basic option)• Contents

– Partial MS-ID masked with sequence (3 bits)

– Data• It can include information about the status of

queued traffic at the AMS such as buffer size and quality of service, including QoS identifiers

• Allocation– CDM based multiplexing– Same sequence with Indicator

• Contents (total 6 bits)– Residual (partial) MS-ID (2~4 bits)– QoS identifier (2~3 bits)– Buffer Size (0 ~ 2 bits)

Time

Fre

qu

en

cy

BW-REQ message: 6 Symbols: spread by identical sequence (length 12) adopted in the BW-REQ Indicator

BW-REQ Indicator: Length 12, : same sequence for three tiles

S1

S2

S3

S4

S5

S6

5/25

Bandwidth Request Channel Structure• Legacy support mode

– Bandwidth Request Channel• A BW-REQ channel consists of 6 distributed BW-

REQ tiles.• A BW-REQ tile is defined as 4 contiguous

subcarriers by 6 OFDM symbols

– Preamble• It can include indicator to notice the ABS of a UL

grant request• Allocation

– CDM based multiplexing with orthogonal sequence of length 12

– Dimension : 2x6 (basic option)• Contents

– Partial MS-ID masked with sequence (3 bits)

– Data• It can include information about the status of

queued traffic at the AMS such as buffer size and quality of service, including QoS identifiers

• Allocation– CDM based multiplexing– Same sequence with Indicator

• Contents (total 6 bits)– Residual (partial) MS-ID (2~4 bits)– QoS identifier (2~3 bits)– Buffer Size (0 ~ 2 bits)

Time

Fre

qu

en

cy

BW-REQ message: 6 Symbols: spread by identical sequence (length 12) adopted in the BW-REQ Indicator


S1

S2

S3

S4

S5

S6

6/25

Simulation Parameters

Common Items Values

Simulation Environments & Assumption for

BRCH

Antenna Configuration 1Tx / 2Rx

Channel Model PB3, VA60, VA120

# of BRCH 1

BRCH structure Three 6x6 tiles

# of MSs 1 or 2

False-Alarm Definition1. Some signals are detected when no signal is transmitted

2. Wrong signals are detected when some signals are transmitted

LGE Items Values

BW-REQ Indicator

Sequence Type DFT

Sequence Length 12 * 3 (same sequence for three tiles)

Target False Alarm 0.1%

Sequence Allocation No-overlapping Sequence Selection / Random Sequence Selection

Sequence Detection Non-coherent

BW-REQ message

Information Size 6 bits

Channel Coding Block Code (6, 12)

Modulation QPSK

Allocation Method CDM (identical sequence with indicator)

Channel Estimation 2-D MMSE

Receiver Type ML

Msg Decoding Method Decode Msg for detected preamble

7/25

Simulation Parameters

INTEL Items Values

BW-REQ Indicator

Sequence Type DFT

Sequence Length 19 * 3 (same sequence for three tiles)

Target False Alarm 0.1%

Sequence Allocation No-overlapping Sequence Selection / Random Sequence Selection

Sequence Detection Non-coherent

BW-REQ message

Information Size 12 bits

Channel Coding Block Code (12, 30) + repetition

Modulation BPSK

Allocation Method CSM

Channel Estimation 2-D MMSE

Receiver Type ML

Msg Decoding Method Decode Msg for detected preamble

8/25

Link Curve (False-alarm Definition 1)

• Ped A (3km/h)– Threshold

• Based on False-alarm Definition 1• Target FA : 0.1%

– Indicator Detection• Target MD Probability : 1%• The performance of LGE’s scheme

outperforms about 1.5dB, because it can utilize even the data region adopted same sequence.

– Message Detection• For the case of one user, LGE’s scheme

achieve at about -2.8dB, while Intel’s scheme achieve 1% BLER at about -1.2dB. (≈ 1.6dB gain)

• For two user case, LGE’s scheme achieve at about -2.8dB, while Intel’s scheme achieve 1% BLER at about -0.8dB. (≈ 2dB gain)

• LGE’s scheme has about 1.6 dB gain for the single user case, and about 2dB gain for two user case.

• In this simulation, LGE’s scheme achieve the relative gain due to short information size while Intel’s scheme doesn’t include false-alarm effect and high muxing order.

BW-REQ Message BLER, Ped A (3km/h)

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

BLER

Intel, 1MS (FA Def1)LGE, 1MS (FA Def1)Intel, 2MS (FA Def1)LGE, 2MS (FA Def1)

Indicator Misdetection, Ped A (3km/h)

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

MD

Pro

bability

.


9/25


• Veh A (60km/h)– Threshold



outperforms about 1.7dB.


achieve at about -1.2dB, while Intel’s scheme achieve 1% BLER at about 0.6dB. (≈ 1.8dB gain)

• For two user case, LGE’s scheme achieve at about -1.2dB, while Intel’s scheme achieve 1% BLER at about 1.0dB. (≈ 2.2dB gain)

• LGE’s scheme has about 1.8 dB gain for the single user case, and about 2.2dB gain for two user case.


Indicator Misdetection, Veh A (60km/h)

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

MD

Pro

bab

ility

.


BW-REQ Message BLER, Veh A (60km/h)

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

BLER


10/25












1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

MD

Pro

bability

.



1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

BLER


11/25


• Ped A (3km/h)– Threshold





achieve at about -3.1dB, while Intel’s scheme achieve 1% BLER at about -1.4dB. (≈ 1.7dB gain)

• For two user case, LGE’s scheme achieve at about -3.0dB, while Intel’s scheme achieve 1% BLER at about -1.0dB. (≈ 2.0dB gain)



Indicator Misdetection, Ped A (3km/h)

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

MD

Pro

bability

.


BW-REQ Message BLER, Ped A (3km/h)

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

BLER


12/25












1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

MD

Pro

bability

.



1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

BLER


13/25







achieve at about 0.2dB, while Intel’s scheme achieve 1% BLER at about 3.0dB. (≈ 2.8dB gain)

• For two user case, LGE’s scheme achieve at about 0.5dB, while Intel’s scheme achieve 1% BLER at about 3.5dB. (≈ 3.0dB gain)




1.00E-03

1.00E-02

1.00E-01

1.00E+00

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

MD

Pro

bability

.



1.00E-03

1.00E-02

1.00E-01

1.00E+00

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

BLER


14/25

Link Curve Analysis

• There are two kinds of link performance according to false-alarm definitions.– LG’s scheme outperforms Intel’s.

15/25

Proposed texts

11.9.2.5 Bandwidth Request Channel

Contention based or non-contention based random access is used to transmit bandwidth request information on this control channel. Prioritized bandwidth requests are supported on the bandwidth request channel. The mechanism for such prioritization is TBD.

The random access based bandwidth request procedure is described in Figure 51. A 5-step regular procedure (step 1 to 5) or an optionaland 3-step quick access procedure (step 1,4 and 5) may beare supported concurrently. The 5-step regular procedure is used as a fallback mode for the 3-step bandwidth request quick access procedure and Step 2 and 3 are used only in 5-step regular procedure. In step 1, AMS sends a bandwidth request indicator for quick access that may indicates information such as partial AMS addressing and/or request size (FFS) and/or uplink transmit power report (FFS), and/or QoS identifiers (FFS), and the ABS may allocate uplink grant based on certain policy. In step 3, the AMS sends BW-REQ message containing different information contents depending on request unit basis (e.g., QoS unit or MS unit). The 5-step regular procedure is used independently or as a fallback mode for the 3-step bandwidth request quick access procedure. In step 5, the AMS sends full AMS addressing with user data only for 3-step quick access procedure and The AMS may piggyback additional BW REQ information along with user data during uplink transmission (step 5). In step 2 and step 4, ABS may send message to acknowledge the reception status.

16/25

Proposed texts (Cont’d)11.9.2.5.2 PHY structure

The bandwidth request (BW REQ) channel contains resources for the AMS to send in BW REQ access sequence at the step-1 of the bandwidth request procedure shown in Figure yyy. Figure aa and figure bb show BW-REQ PHY structures for green field and legacy support mode. A BW REQ channel consists of 3 distributed BW-REQ tiles and each A BW REQ tile is defined as 6 contiguous subcarriers by 6 OFDM symbols. Each BW REQ channel consists of 3 distributed BW-REQ tiles. in green field. And in legacy support mode, a BW REQ channel consists of 6 distributed BW-REQ tiles and each tile is defined as 4 contiguous subcarriers by 6 OFDM symbols.

Time

Freq

uenc

y

BW-REQ message: 6 Symbols: spread by identical sequence

(length 12) adopted in the BW-REQ Indicator


S1

S2

S3

S4

S5

S6

Time

Fre

qu

en

cy

BW-REQ message: 6 Symbols: spread by identical sequence

(length 12) adopted in the BW-REQ Indicator


S1

S2

S3

S4

S5

S6

Figure aa. BW REQ PHY structure for green field Figure bb. BW REQ PHY structure for legacy support mode

17/25

Appendix

• Simulation Criteria• Performance Metric for Indicator• Performance Metric for Message• Threshold & False-alarm Probability• BR Rate

18/25

Simulation Criteria• Link-level Simulation

Mandatory[Link Reliability – Initial Comparison]– # of Users : 1 or 2– Sequence Allocation

• Random Selection– Channel Estimation : 2-D MMSE– Message Detection : MLD

[Latency]– Cell Configuration : Single Cell– Traffic Model : VoIP– # of Users : 500 per cell (sector)

• BR according to VoIP model• Mean Talk Spurt = 2.5 sec

– Sequence Allocation• Random Selection

– Full Bandwidth Request Operation• Retry, Frame Delay, Fallback Mode• No Process Delay• Channel Estimation : 2-D MMSE• Message Detection : MLD

• System-level Simulation Optional

– Throughput (w. cell coverage)– Cell Configuration : 57 sectors (2 tiers)– Traffic Model : VoIP

• BR & Real VoIP Traffic– # of Users : 500 per sector

• BR according to VoIP model• Mean Talk Spurt = 2.5 sec

– Sequence Allocation• Random Selection

– Full Bandwidth Request Operation• Retry, Frame Delay, Fallback Mode• No Process Delay• Channel Estimation : 2-D MMSE• Message Detection : MLD

– Power Control (?)– Scheduling (?)– Message False-alarm

19/25

Performance Metric for Indicator

• Definition of False Alarm– Receiver detects unwanted BR whether there are some BR signals or no BR signal.– False Alarm wrong sequence detection resource waste– False Alarm depends on cross correlation properties of multiplexing sequences as well as

channel selectivity & mobility– Target False Alarm=0.1% (ref. Ranging)

• Threshold– Fixed threshold

• Fixed one threshold per SNR level regardless Channel Selectivity and mobility (AWGN)

• Fixed one threshold for all SNR but different for channel selectivity and/or mobility

– Adaptive threshold• SNR

• Channel Selectivity

• User Mobility

• Misdetection Probability– Receiver can’t detect BR– Target Misdetection Probability=1% (ref. Ranging)

20/25

Performance Metric for Message

• Message Error– False Alarm regarding performance metric

• Link-level– Ideal message false alarm detection

• System-level only– Threshold : power level, channel quality (e.g. RSSI, CSI)– Metric Value > Threshold

» message error False Alarm– Metric Value < Threshold

» message error turn into Regular Access

– BLER• All cases of message error including Indicator error

– Indicator detection fail» misdetection

– Indicator detection fail but message error» indicator collision, message error

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Threshold & False-alarm Probability

• Ped A (3km/h)Threshold, Ped A (3km/h)

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

Thre

shold

Intel, FA Def1LGE, FA Def1

Indicator False-alarm, Ped A (3km/h)

1.00E-05

1.00E-04

1.00E-03

1.00E-02

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

FA

Pro

bability

.


Threshold, Ped A (3km/h)

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

1.600

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

Thre

shold


Indicator False-alarm, Ped A (3km/h)

1.00E-05

1.00E-04

1.00E-03

1.00E-02

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

FA

Pro

bability

.


22/25


• Veh A (60km/h)

Threshold, Veh A (60km/h)

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

Thre

shold


Indicator False-alarm, Veh A (60km/h)

1.00E-04

1.00E-03

1.00E-02

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

FA

Pro

bability

.



0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

Thre

shold



1.00E-05

1.00E-04

1.00E-03

1.00E-02

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

FA

Pro

bability

.


23/25


• Veh A (120km/h)Threshold, Veh A (120km/h)

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

Thre

shold



1.00E-04

1.00E-03

1.00E-02

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

FA

Pro

bability

.



0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

Thre

shold



1.00E-05

1.00E-04

1.00E-03

1.00E-02

-10 -8 -6 -4 -2 0 2 4 6SNR (dB)

FA

Pro

bability

.


24/25

BR Rate

• Initial BR Rate– Traffic Model : VoIP– # of VoIP user : 500 / 10 MHz (refer SRD 8.3 (Max Indoor))– Mean Talk Spurts

• 50% Voice Activity 1.25 sec.• Bi-directional : 2.5 sec. (refer EMD) Exponential Distribution with mean = 2.5 sec.

– Mean # of BW-REQ/Frame/Sector• BR Rate = K VoIP users/sector * N BR/frame = KN BR/Frame/sector

0.4BW-REQ per 200 frames BW-REQ/500frame500users/sector * BW-REQ/500frame = 1 BW-REQ/Frame/Sector

– Mean Call Time : 180 sec.– # of opportunity / Frame = 1

• Timer– Packet Access Delay Boundary : 50 ms

• Back-off– Random Back-off [0, 40ms]

25/25

BR Rate (Cont’d)

• VoIP Packet Transmission

20ms Mean 1.25 sec

Active Inactive

Mean 1.25 sec

50% Voice Activity Bandwidth Request VoIP Packet

Call Duration

2

2

ln ln1exp

22

49.113, 1.0041

x

x mq x

where m

- Call Duration : Lognormal Distribution based on K-L Divergence Method¶

¶ J. Guo, F. Liu, and Z. Zhu, “Estimate the call duration distribution parameters in GSM system based on K-L divergence method,” in Proceedingsof the International Conference on Wireless Communications, Networking and Mobile Computing (WiCom 2007), 2007, pp. 2988–2991.

c80216m-09_0015.ppt

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