doc.: ieee 802.11-05/0433 submission may 2005 motorola, nokia, samsungslide 1 handsets requirements...

May 2005

Motorola, Nokia, Samsung

Slide 1

doc.: IEEE 802.11-05/0433

Submission

Handsets requirements for TGn

Notice: This document has been prepared to assist IEEE 802.11. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.

Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.11.

Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures <http:// ieee802.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 < [email protected]> as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.11 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at <[email protected]>.

Date: 2005-05-16Author

Name Company Address Phone Email

Marc de CourvilleMarkus Muck MOTOROLA Gif-sur-Yvette 91193 France +33 1 69352518 [email protected]

[email protected]

Nico van Waes NOKIA 6000 Connection Dr, Irving TX +1 9728945669 [email protected]

Dongjun Lee Youngsoo Kim SAMSUNG

Mt. 14-1 Nongseo-Ri,Giheung-Eup,Yongin-Si,

Gyeonggi-Do, Korea 449-712 +82 312809614 [email protected]

[email protected]

May 2005


Slide 2

doc.: IEEE 802.11-05/0433

Submission

Disclaimer This presentation intends to:

■ Be alliance agnostic■ Focus only on technical requirements, not solutions■ Provide a framework and requirements to help put

into perspective the technical solutions provided to the TGn body with respect to specific handset usage models

May 2005


Slide 3

doc.: IEEE 802.11-05/0433

Submission

Why care about handsets in 11n? Handsets will be the dominant WiFi platform within a few years Relegating handsets to the use of legacy WiFi will delay the

adoption rate of 11n

Requirements to support handsets are modest (not delay-inducing)

Why 11n: new project would completely miss market and raise interworking issues

May 2005


Slide 4

doc.: IEEE 802.11-05/0433

Submission

Multi-mode handsets The trend in handsets is towards the combination of multiple air-interfaces to

cover the widest spectrum of throughput vs distance and connectivity to other platforms.

11n will not fill the entire needed capability space and is no threat to other air interfaces (no one size fits all)

Addition of 11n to handsets is a natural fit from both a capability and interconnectivity viewpoint

Bro

adba

ndN

arro

wba

nd

Local Area Wide Area

Typ

ical

Use

r D

ata

Rat

e

Bluetooth

3G

2.5G

1G

Wi -Fi

b

Wi -Fi

b

Bro

adba

ndN

arro

wba

nd


Typ

ical

Use

r D

ata

Rat

e

Bluetooth

CellularEvolutionCellularEvolution

cellularNon-EvolutionNon-Evolution

3G

2.5G

1G

Wi -Fi

a/g

Wi -Fi

a/g

UWBUWB

Wi -Fi

n

Wi -Fi

n

3.5/3.9/4G3.5/3.9/4G

Multi -modehandset

Multi -modehandset

Bro

adba

ndN

arro

wba

nd


Typ

ical

Use

r D

ata

Rat

e

Bluetooth

3G

2.5G

1G

Wi -Fi

b

Wi -Fi

b

Wi -Fi

b

Wi -Fi

b

Bro

adba

ndN

arro

wba

nd


Typ

ical

Use

r D

ata

Rat

e

Bluetooth

CellularEvolutionCellularEvolutionCellularEvolutionCellularEvolution

cellularNon-EvolutionNon-Evolution

cellularNon-EvolutionNon-EvolutionNon-EvolutionNon-Evolution

3G

2.5G

1G

Wi -Fi

a/g

Wi -Fi

a/g

Wi -Fi

a/g

Wi -Fi

a/g

UWBUWBUWBUWB

Wi -Fi

n

Wi -Fi

n

Wi -Fi

n

Wi -Fi

n

3.5/3.9/4GNext generationcellular

Multi -modehandset

Multi -modehandset

Multi -modehandset

Multi -modehandset

May 2005


Slide 5

doc.: IEEE 802.11-05/0433

Submission

Handsets device size constraint Motivation: handsets (phone/PDA) will play a major role in the internet

anywhere anytime vision Constraints: reduce number of antennas to

■ allow to reduce overall cost and power consumption of the device (analog RF-FE)■ account for device size limitation (7cm x 4cm)

TGn needs to be scalable enough to address AP and mobile STA in an evolutionary manner

Asymmetric antenna configuration is a must

Projections:■ 1 antenna immediate and long term

low end solutions■ 2 antennas handsets: 2007-2008■ 3-4 antennas handsets (high end

PDA with larger screen): 2012

May 2005


Slide 6

doc.: IEEE 802.11-05/0433

Submission

Robust lower rates for extended range Benefit from spatial

diversity: provides a link budget gain that can be used to

■ Either increase the peak data rate

■ Extend the range of coverage of classical legacy 11a/g transmission modes

Note: ■ range extension is by no

means targeting WMAN coverage (wide area), it remains for the local area business (50% increase with 2x2 solutions)

May 2005


Slide 7

doc.: IEEE 802.11-05/0433

Submission

3 environments of interest for handsets:■ enterprise: lower infrastructure cost with fewer access

points for covering the same area while serving more connections (cat5e cable, labor, equipment saving)

■ home: achieve full home coverage with one access point, having 11n handsets performing e.g. VoIP telephony bridging on ADSL

■ limited outdoor (hotspot): as extension of the home or to provide solution to be coupled with 3G services

Environments considered for range extension

May 2005


Slide 8

doc.: IEEE 802.11-05/0433

Submission

Challenges to grant range extension 4 main features need to be ensured

■ Ensure presence of PHY modes that • enables enough coverage for target packet error rate envisaged for handset applications: VoIP,

video streaming• do not strive for highest rates, allow a number of spatial streams lower than the number TX

antennas!■ Enable association at extended range (ER): legacy beacon doesn’t allow extended range

stations to associate■ Coexistence: if these PHY modes are not mandatory then MAC protection mechanisms

will be required to allow peaceful coexistence of extended/normal range (ER/NR) stations

■ Enable robust signaling: define an 11n specific signal field or extension of current legacy one that enables stations at a larger range to be able to understand the parameters of the incoming packets

Preambles SIG Data

The parameter definitions must be available for both, NRand ER devices

Data symbols are NR/ER mode dependent

Preambles are identical for NR/ER modes

AP

ER-STAs

NR-STAs

ER-STAs

ER-STAs

May 2005


Slide 9

doc.: IEEE 802.11-05/0433

Submission

Power consumption Power consumption is THE critical factor in handset

capabilities■ Battery capacity is small (~1Ah)■ Heat dissipation is difficult■ Customer perception does not favor frequent recharging

Scope of 11n PHY naturally creates new challenges due to increased number of transceiver chains and data speeds

MAC protocols should be evaluated to examine where power efficiency can be improved or at least less deteriorated.

■ Aggregation mechanisms are prime candidates

May 2005


Slide 10

doc.: IEEE 802.11-05/0433

Submission

Multi-receiver aggregation I Avoiding (blind) multi-receiver aggregation e.g. 11e APSD:

■ Minimal bandwidth efficiency■ Minimal power consumption

Using (blind) multi-receiver aggregation:■ Maximum bandwidth efficiency■ Maximum power consumption

Above mutually exclusive benefits can both substantially be achieved by resource announcements in multi-receiver aggregates

■ Allows devices without data in aggregate to stop receiving■ Allows devices with data in aggregate to receive only part of the

aggregate■ Allows reverse link scheduling for increased reverse link efficiency

in both power and throughput

May 2005


Slide 11

doc.: IEEE 802.11-05/0433

Submission

Multi-receiver aggregation II

Example of power consumption vs time

Listen Rx TxSIFS SIFS RxACK

Listen Rx aggregate with or without address list Tx RxACK

schemedependentposssiblemultipleresponse receptions

Listen

Rx aggregate with resource announcement Tx SIFSRx


RxACK

Otherresponses

irrelevantreceptionandfirstresponses

Listen Rx TxSIFS SIFS RxACK

Listen Rx aggregate with or without address list Tx RxACK


Listen

Rx aggregate with resource announcement Tx SIFSRx


RxACK

Otherresponses

irrelevantreceptionandfirstresponses

May 2005


Slide 12

doc.: IEEE 802.11-05/0433

Submission

Single-receiver aggregation Power consumption is reduced by decreasing the number of

bursts in which data and control info is transferred Single-receiver aggregation is a good method to reduce the

number of bursts However, failure to enable aggregation of multiple TIDs

reduces the desired effectiveness of single-receiver aggregation

■ Handset-critical applications can generate multiple QoS class traffic (e.g. video-telephony can use voice, video and control (TCP) traffic)

■ Even if transmissions fall within the same class, different characteristics (e.g. PER) and hence different TIDs can be required.

Above can be trivially achieved by augmenting the Block ACK definition

May 2005


Slide 13

doc.: IEEE 802.11-05/0433

Submission

Small-Size Packet Support Requirements VoIP is the current killer-application for

handsets■ Designed in such a way to meet voice-specific

quality requirements■ Small-size packets: ranging from 4 to 160 bytes

Implications of small-size packets■ MAC efficiency■ Relevance of advanced

coding

May 2005


Slide 14

doc.: IEEE 802.11-05/0433

Submission

Need for Efficient MAC Protocol

Known fact: throughput performance of 802.11-based MAC degrades when decreasing packet size■ For a packet of 100-byte payload, the efficiency of

802.11 MAC is ~10% Efficient frame aggregation mechanism needs

to be specified that does not violate other QoS requirements inherent in handheld applications

May 2005


Slide 15

doc.: IEEE 802.11-05/0433

Submission

Relevance of Advanced Coding (AC) for Short Packets

Key requirements for ACs■ Minimize the performance loss due to the codeword size

granularity■ Reasonable complexity / latency with sufficient coding gain

Most suitable codeword size that meets these requirements falls on the range of 500~2500 bits

■ Typical VoIP packets are much shorter than this■ AC should support adequate gain for short packet with

minimum overhead to efficiently handle handset implementation

May 2005


Slide 16

doc.: IEEE 802.11-05/0433

Submission

Short-Packet Performance of ACs

Typical gain of LDPC over CC is 1.5~3dB■ TGn CC67 simulations■ Codeword length is ~2000 bits

Few AC performance results for shorter packets are available in TGn

In 802.16e, it was reported that gain of LDPC over CC reduces to ~0.5dB for the codeword as short as 576 bits

It is known that Turbo code with identical code size performs a little better than 802.16e LDPC

May 2005


Slide 17

doc.: IEEE 802.11-05/0433

Submission

Implementation Complexity of ACs Gate count complexity is a function of a variety of

factors such as:■ degree of parallelism, number of iterations, codeword size

Duo binary TC: ~450K gates■ Max block size: 2048■ Decoder throughput: 480Mbps at 200MHz clock rate■ # of iterations: 5

LDPC■ Not very well documented yet■ ~400~600K with similar decoder throughput

May 2005


Slide 18

doc.: IEEE 802.11-05/0433

Submission

Conclusions WiFi-enabled handset market is growing at an impressive pace

■ Handheld devices are expected to be dominant platform on which WiFi is implemented

Therefore, TGn should■ NOT neglect this tremendous market opportunity■ Give full consideration to handheld requirements so that TGn standard

will enable implementation into handsets■ Cooperate constructively in an alliance-agnostic fashion in order to

make this happen We would like to propose to build on and extend this

contribution to capture and benchmark solutions: make it a living effort. This is an open invitation for contributions!

doc.: ieee 802.11-05/0433 submission may 2005 motorola, nokia, samsungslide 1 handsets requirements...

Documents

aggregation mechanisms

power efficiency

larger range

aggregation of multiple

extended range stations

extended range er

number of burstshowever

range extension3 environments