WiMAXIEEEWirelessMANs.pptVIP

Sridhar Iyer IIT Bombay WiMAX: IEEE 802.16 - Wireless MANs Sridhar Iyer K R School of Information Technology IIT Bombay sri@it.iitb.ac.in http://www.it.iitb.ac.in/~sri Wireless networks Wireless PANs (Bluetooth – IEEE 802.15) very low range wireless connection to printers etc Wireless LANs (WiFi – IEEE 802.11) infrastructure as well as ad-hoc networks possible home/office networking Multihop Ad hoc Networks useful when infrastructure not available, impractical, or expensive military applications, emergencies WiMAX Goal: Provide high-speed Internet access to home and business subscribers, without wires. Base stations (BS) and subscriber stations (SS) Centralized access control to prevents collisions Supports applications with different QoS requirements WiMAX is a subset of IEEE 802.16 standard IEEE 802.16 standards 802.16.1 (10-66 GHz, line-of-sight, up to 134Mbit/s) 802.16.2 (minimizing interference between coexisting WMANs) 802.16a (2-11 Ghz, Mesh, non-line-of-sight) 802.16b (5-6 Ghz) 802.16c (detailed system profiles) P802.16e (Mobile Wireless MAN) Physical layer Allows use of directional antennas Allows use of two different duplexing schemes: Frequency Division Duplexing (FDD) Time Division Duplexing (TDD) Support for both full and half duplex stations Adaptive Data Burst profiles Transmission parameters (e.g. Modulation, FEC) can be modified on a frame-by-frame basis for each SS Profiles are identified by ”Interval Usage Code” Time Division Duplexing (TDD) Media Acces Control (MAC) Connection oriented Connection ID (CID), Service Flows Channel access: decided by BS UL-MAP Defines uplink channel access Defines uplink data burst profiles DL-MAP Defines downlink data burst profiles UL-MAP and DL-MAP are both transmitted in the beginning of each downlink subframe TDD Downlink subframe Uplink subframe Uplink periods Initial Maintenance opportunities Ranging - to determine network delay and to request power or profile changes Collisions may occur in this i