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

About the Speaker Dr. Osama Aboul-Magd is working at Huawei Technologies, Canada Research Center. He led the task group (TG) in IEEE leading to the design of the IEEE02.11ac. He is currently chairing the TG in IEEE designing AX enhancements to WLAN. He taught courses on communication systems and computer networks at Carleton University from

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. 3

Traditional WLAN Markets 4 Home Networking (Fast Synch and Video Distribution) Enterprise Networking

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. 5

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. 6

A Second View of WLAN Architecture 7

8 Mainly driven by technological advances in communication systems and signal processing PHY Evolution: The Holy Grail ’sWe are here! Mbps b 11Mbps a (5GHz), g (2.4GHz) 54Mbps n 600Mbps ac (5GHz) ad (60GHz) 6.7~6.9Gbps The main focus has been on increasing throughput – usually by an order of magnitude OFDMMIMOMU-MIMO 8

Wired and Wireless Speeds 9

IEEE PHY Layers IEEE b is not the first WLAN PHY layer, but it is the one that have seen much popularity IEEE a/g increased the data rates up to 54 Mbps IEEE n was an inflection point where MIMO was first introduced WLAN IEEE Legacy A/B/G HT, VHT, HEW N AC AX mmWave AD AY White Spaces AF Sub 1 G AH 10

PHY Layers 11 TVWS/AFSub 1G/AHVHT/ACWiGig/AD FeaturesLong rangeLow power, Extended Range Dual-bandShort range, Very high speed MarketsOTTOperator, Specific segment Consumer, Enterprise, Operator Consumer, Enterprise Usage ScenariosWide-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 1 st Generation Ready 2 nd Generation: 2015 Some chipsets and products ready

From IEEE n to IEEE ac 12 FeatureIEEE nIEEE ac Frequency Band2.4 and 5 GHz5GHz Channel Width20 MHz 40 MHz (optional) 20/40/80 MHz 160 and MHz (optional) Static/Dynamic BWX√ Backward Compatibility802.11b/g a a/n OFDM√√ MIMOSU MIMO Up to 4 antennas SU and DL MU MIMO Up to 8 antennas PreambleMixed Format (MF) Green Field (GF) Mixed Format (MF) only. Modulation and Coding Schemes76 MCS256 QAM and r=5/6 Beamforming (optional)Staggered and NDPNDP CodingBCC/LDPC (optional)

Enterprise WLAN Deployments 13 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

14 Dual/Tri-band Chipsets Coming!

… but the world hasn’t stayed still. Usage cases have evolved to 15

New Usage Cases 16 Wireless Office Lecture Hall Public Transportation Stadium Carrier Wi-Fi Airport Concourse

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. 17

Notable MAC Enhancements 18 IEEE e WLAN Quality of Service IEEE v Wireless Network Management IEEE u Interworking with External Networks IEEE i and IEEE w Security related amendments Together they form the basis for HotSpot and Carrier offloading

Hot Spots Reference Configuration 19 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). 19 Source: Passpoint TM (release 1) Deployment Guidelines

But it is not enough. A new flavor of WLAN is required and there are challenges…. 20

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. 21

22 Can Wi-Fi tackle these challenges?

23 A new Project has started High Efficiency WLAN (HEW) IEEE ax

The Scope of the New Project This amendment defines standardized modifications to both the IEEE physical layers (PHY) and the IEEE 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 devices operating in the same band. 24

Emerging Design Trends Backward compatibility requires the use of the same frame format as in other existing IEEE 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. 25

A Quick Overview of ax 26 The use of Orthogonal Frequency Division Multiple Access (OFDMA) – Allows the multiplexing of multiple users in the frequency domain. A departure from the use of the OFDM where all resources are assigned to a single user as in previous IEEE amendments. – Support of OFDMA is both for the Uplink (UL) and the Downlink (DL) Supporting UL MU MIMO – DL MU MIMO support is already in IEEE ac. – Allows multiplexing of multiple users in the spatial domain The use of 256 FFT for the data portion of the ax PPDU. – A departure from the 64 FFT used in previous IEEE amendments. Additional guard interval durations for outdoor channels (0.8, 1.6, and 3.2  sec) Source: ax-payload-symbol-size-for-11ax.pptxhttps://mentor.ieee.org/802.11/dcn/15/ ax-payload-symbol-size-for-11ax.pptx

Closing Note The 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 27