Review of Mobile Broadband Wireless Access (MBWA) technologies(IEEE 802.16e and IEEE 802.20) By Thikriat Al mosawi November 2004
OUTLINE • Introduction: what is the Broadband Wireless Access (BWA) • Benefits of BWA • Two technologies • IEEE 802.16 • IEEE 802.20 • An overview and • Technical issues
Introduction What is a BWA? • High speed connection • Uses radio waves • Point to multipoint system
Benefits of BWA • High speed data, voice and video services • Faster time to market and lower total cost of ownership • Last-mile connection • Flexible • reliability • Competitive environment
IEEE 802.16 an overview IEEE 802.16 MAN Standard will be able to connect 802.11 hotspots to the internet. provides up to 31 miles of service area range. has developed a point-to-multipoint broadband wireless access standard for systems in the frequency ranges 10-66 GHz and sub 11 GHz. the standard covers both MAC and the PHY layers. Two technologiesIEEE 802.16 and IEEE 802.20
IEEE 802.16e(Mobile Wireless MAN) • It was approved on the 23rd of September 2004 • It is a modification to IEEE Standard 802.16 • It covers MAC and PHY layers for Combined Fixed and Mobile Operation in Licensed Bands. • It will enable a mobile user to keep their connection while moving at vehicular speed (75-93 miles/h).
WiMAX Forum • It is a non-profit organization • It was formed in 2003 • It supports the IEEE 802.16 Broadband Wireless Access • It has more than 110 members such as Alcatel, AT&T, Intel, Nortel, Motorola, SBC, Siemens, and so forth.. • Rosedale is the first WiMAX chipset
WiMAX Technology • Worldwide Interoperability of Microwave Access (WiMAX) • It will provide fixed, nomadic, portable and, eventually, mobile wireless broadband connectivity. • connectivity at rates of up to 75 Mb/sec • WiMAX 10-66 GHz technical working group - two MAC system profile - two primary PHY system profile • WiMAX 2-11 GHz technical working group - defining MAC and PHY system profile for IEEE 802.16e and HiperMAN standards.
IEEE 802.16 Technology design issues • It was designed to develop an air interface based on a common MAC protocol. • Designed a flexible MAC layer and accompanying physical layer (PHY) for 10-66 GHz.
Physical Layer • The 10-66 GHz PHY assumes line-of-sight propagation • It contains several forms of modulations and multiplexing to support different frequency ranges and applications • Data rates determined by exact modulation and encoding schemes.
Medium Access Control (MAC) • Designed for point-to-multipoint BWA applications. • The original design of MAC is flexible enough to support, with extension, all other projects of the IEEE 802.16 • Addresses the need for very high bit rates for both uplink and downlink.
IEEE 802.16eMBWA technology related issues • IEEE802.16e Mobility Enhancements -MAC and PHY enhancements -Power consumption reduction -Hand-Off • Mobility Management -Control by L2.5 Routing
IEEE 802.16eMBWA technology related issues MAC and PHY enhancements - The proposal addresses the need for fast correction , frequency and timing. -The proposed PHY layer is based on OFDM/OFDMA - The configuration offers simplicity for both fixed and mobile implementations
IEEE 802.16eMBWA technology related issues Power Consumption Reduction -Battery power for the Mobile Terminal -Introduce two modes for the SS: Awake-mode and Sleep-Mode • Awake-mode: is when SS is receivingand transmitting PDUs in a normal fashion • Sleep-Mode: is whenthe SSmay power down. It has two parameters: Sleep-interval and Listening-interval
IEEE802.16e Mobility Enhancements Handoff • Optimize L2 handoff • Provide trigger to L3 • Allow mobile SSs to move efficiently between BSs • Smooth BSs transitions with minimal loss of PDUs • Fast BSs transition to guarantee QoS
Mobility Management • Communication link between terminal and the Internet must be preserved • IP address should stay the same even a terminal changes its location
Mobility Management • In a multi-hop network several paths exists. • a tunnel needs to be created to allow send or receive packets from or to known IP address of a terminal • The tunnel must follow the movement of the terminal
Mobility Management • The 802.16e aim is : • To find the best path between terminal and gateway node. • The tunnel should be the best path • Also the bandwidth must be guaranteed
Mobility Control by L2.5 Routing • Three possibilities can be considered to set up a tunnel either by using L1 or L3 or L2.5. • The IEEE 802.16e proposed is to use L2.5 label to set up tunnels.
Creating tunnels by using L1 • It is not scalable • It will have complex routing as the BS getting bigger.
Creating tunnels by using L3 • It is very complicated • path control depends on IP • IP is wrapped by IP
Creating tunnels by using L2.5 802.16e proposal • An appropriate path will be set up • Getting path control over heterogeneous physical • The path control is independent from the IP layer • Both IPv4 and IPv6 can be used at the same time
IEEE 802.20 MBWAan overview • MBWA Working Group was approved on the 11th of December 2002 • To prepare a formal specification for a packed-based air interface designed for IP-based services with peak data rates per user in excess of 1 Mbps • Will address MBWA in licensed bands below 3.5 GHz MBWA • Could provide commuters with reliable high-speed wireless voice and data links from trains and cars travelling at up to 250km/h (155miles/h).
IEEE 802.20 Technology Design Issues • It specifies the PHY and MAC layers of an air interface • Its system reference architecture will be based on a layered architecture • The MAC layer may consist of common part and a PHY-specific part if more than one PHY technology is adopted
IEEE 802.20MBWA technology related issue • Seamless Handover between 802.20 MBWA/802.11/802.15 • Fast handover • Traffic model
Seamless Handover between 802.20 MBWA/802.11/802.15 • They propose an adaptation layer (Virtual Interface) to interact with the IP and Data link layer. • They provide a unique virtual MAC address
Fast handover • They address the benefits of providing layer 2 hints (triggers) to the network layer • Fast handovers anticipate movement with the help of link layer (triggers)
Traffic model • The 802.20 Traffic Models is a subgroup of 802.20 Channel and Traffic Model Group • Traffic Models is needed because MBWA will have multiple types of IP-based services • There will be a mix of user applications and various different user scenarios
Traffic model • Traffic and application details depend on user and device scenario • Laptop • PDA • Smart phone
Traffic types • Web browsing • FTP (File Transfer Protocol) • E-mail • WAP (Wireless Application Protocol) • VoIP • Video telephony/ videoconference • Audio streaming • Gaming • File-sharing
Traffic mix • Different types of devices such as laptop, PDA and phone. • Different services from same device or user such as web-conference (Web +audio) v. single –service (E-mail). • Different level of use (intense V. light) • Different demand on response time ( real-time Vs. best-effort)
Conclusion • IEEE 802.20 and IEEE 802.16e standards seem very similar. But there are some important differences !!! 802.16e 802.20 • It is starting from scratch • It is the extension of an existing • standard • It operates in the licensed band below • 3.5 GHz • It operates in the 2 to11 GHz • licensed spectrum • Speeds of 75 to 93 miles/h • Speeds of 155 miles/ h