SYSC-4700 Wireless LAN/Wi-Fi II Osama Aboul-Magd Huawei Technologies 1.

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SYSC-4700

Wireless LAN/Wi-Fi II

Osama Aboul-MagdHuawei Technologies

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About the Speaker

• Dr. Osama Aboul-Magd is working at Huawei Technologies, Canada Research Center.

• He led the task group (TG) in IEEE 802.11 leading to the design of the IEEE02.11ac.

• He is currently chairing the TG in IEEE 802.11 designing AX enhancements to WLAN.

• He taught courses on communication systems and computer networks at Carleton University from 2005-2009.

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Introduction

• This lecture is a continuation of lecture 22 on Wireless LAN/Wi-Fi technologies.

• This lecture focuses on the evolution of the wireless LAN (WLAN) technology and new trends.

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Traditional WLAN Markets

Home Networking(Fast Synch and Video Distribution)

Enterprise Networking

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WLAN Evolution - Drivers

• The evolution of WLAN technology has always been in response to the needs of its key markets– The need for speed by traditional WLAN

enterprise and consumer electronics markets• Advances in communication systems and

signal processing technologies• The main focus has always been on increasing

the data rate.

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WLAN Evolution – Layered Approach

• Over the years, WLAN technology has evolved both at the PHY and the MAC layers.

• MAC evolution has centered around QoS and reducing MAC overhead.

• PHY layer is considered to be the engine that enables the growth in data rates.– Traditionally PHY enhancements are more

celebrated than those of the MAC.

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A Second View of WLAN Architecture

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Mainly driven by technological advances in communication systems and signal processing

PHY Evolution: The Holy Grail

1997 2000’s We are here!

802.112Mbps

802.11b11Mbps

802.11a (5GHz), 802.11g (2.4GHz)54Mbps

802.11n600Mbps

802.11ac (5GHz)802.11ad (60GHz)6.7~6.9Gbps

The main focus has been on increasing throughput – usually by an order of magnitude

OFDM MIMO MU-MIMO

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Wired and Wireless Speeds

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IEEE 802.11 PHY Layers

• IEEE 802.11b is not the first WLAN PHY layer, but it is the one that have seen much popularity

• IEEE 802.11a/g increased the data rates up to 54 Mbps• IEEE 802.11n was an inflection point where MIMO was first introduced

WLAN

IEEE 802.11

Legacy

A/B/G

HT, VHT, HEW

N

AC

AX

mmWave

AD

AY

White Spaces

AF

Sub 1 G

AH

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PHY Layers

TVWS/AF Sub 1G/AH VHT/AC WiGig/ADFeatures Long range Low power,

Extended RangeDual-band Short range,

Very high speed

Markets OTT Operator, Specific segment

Consumer, Enterprise,Operator

Consumer,Enterprise

Usage Scenarios Wide-area coverage: rural areas, in-house video distribution

Sensor,Smart grid

Cellular offload,Wireless connectivity

Cable replacement,Wireless display,Wireless docking

Time to Market(Chipset/Equipment)

Proprietary Solution Ready

Subject to demand 1st Generation Ready2nd Generation: 2015

Some chipsets and products ready

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From IEEE 802.11n to IEEE 802.11acFeature IEEE 802.11n IEEE 802.11ac

Frequency Band 2.4 and 5 GHz 5GHz

Channel Width 20 MHz40 MHz (optional)

20/40/80 MHz160 and 80+80 MHz (optional)

Static/Dynamic BW X √

Backward Compatibility 802.11b/g802.11a

802.11a/n

OFDM √ √

MIMO SU MIMOUp to 4 antennas

SU and DL MU MIMOUp to 8 antennas

Preamble Mixed Format (MF)Green Field (GF)

Mixed Format (MF) only.

Modulation and Coding Schemes 76 MCS 256 QAM and r=5/6

Beamforming (optional) Staggered and NDP NDP

Coding BCC/LDPC (optional) BCC/LDPC (optional)

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Enterprise WLAN Deployments

• Enterprise Wi-Fi deployment is becoming more and more popular

• Migration from legacy to faster technologies (11n/ac) supporting higher data rates

Infonetics research Inc, 2Q 2012

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Dual/Tri-band Chipsets Coming!

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… but the world hasn’t stayed still. Usage cases have evolved to

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New Usage Cases

Wireless Office

Lecture Hall

Public Transportation

Stadium CarrierWi-Fi

Airport Concourse

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New Usage Cases = New Requirements

• Improved user experience in carrier off-loading– Per user throughput rather than aggregate data rate is

now the important measure.• Explosive growth in traffic due to video uploading

and downloading– Video traffic represents over 60% of the total traffic.

• New usage cases are mainly characterized by dense environment.– Many Access points (AP) deployed in limited

geographical areas and many devices per access point.

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Notable MAC Enhancements

IEEE 802.11e•WLAN Quality of Service

IEEE 802.11v•Wireless Network Management

IEEE 802.11u•Interworking with External Networks

IEEE 802.11i and IEEE 802.11w•Security related amendments

Together they form the basis for HotSpot and Carrier offloading

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Hot Spots Reference Configuration

• Device detects Hotspot 2.0 indication in access point (AP) beacon frame.• Device queries ANQP server for 3rd Generation Partnership Project (3GPP) cellular network information and

roaming consortium organizational identifiers (OIs).• Device matches the information and OIs received against its list of credentials and preferred networks. • Device automatically associates with Passpoint AP.• Device performs Institute of Electrical and Electronics Engineers (IEEE) 802.1X authentication to the home

authentication, authorization and accounting (AAA) server using Extensible Authentication Protocol–Subscriber Identity Module (EAP-SIM) or EAP Authentication and Key Agreement (EAP-AKA). ‑

• Home AAA server communicates with home location register (HLR) using the Mobile Application Part (MAP).

19Source: PasspointTM (release 1) Deployment Guidelines

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But it is not enough. A new flavor of WLAN is required and there are challenges….

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Challenges• Modulation and coding gain is approaching its theoretical

limits. Further increase in link throughput may not be easy.

• Wi-Fi is penetrating the carrier space with possibly different set of requirements for offloading, e.g., QoS/QoE support.

• Dense deployment of stations and access points are now the norm. Access for all should be maintained.

• Traditionally deployed indoor, Wi-Fi is increasingly deployed outdoor with different channel conditions.

• Large discrepancy between useful throughput (Goodput) and physical layer throughput.

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Can Wi-Fi tackle these challenges?

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A new Project has started

High Efficiency WLAN (HEW)

IEEE 802.11ax

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The Scope of the New Project• This amendment defines standardized modifications to both the

IEEE 802.11 physical layers (PHY) and the IEEE 802.11 Medium Access Control layer (MAC) that enable at least one mode of operation capable of supporting at least four times improvement in the average throughput per station (measured at the MAC data service access point) in a dense deployment scenario, while maintaining or improving the power efficiency per station.

• • This amendment defines operations in frequency bands between 1

GHz and 6 GHz. The new amendment shall enable backward compatibility and coexistence with legacy IEEE 802.11 devices operating in the same band.

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Emerging Design Trends

• Backward compatibility requires the use of the same frame format as in other existing IEEE 802.11 PHYs.

• Employing OFDMA to allow the multiplexing of multiple users in a single transmission.

• Allow for clients to request resources based on their buffer occupancy.

• Allow the AP to allocate resources to clients as needed.

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Closing NoteThe advance of technology is based on making

it fit in so that you don’t really notice it, so it becomes part of everyday life- Bill Gates