Performance Evaluation of the IEEE MAC for QoS Support Aemen Hassaan Lodhi

Outline IEEE (WiMAX) MAC layer Project Objective Simulation Environment Performance Metrics Work accomplished Future strategy

IEEE (WiMAX) Wireless MAN – provides network access to subscriber stations (SS) with radio base stations (BS) Offers an alternative to cabled access networks – fiber optic links, coaxial cables using cable modems, DSL links Supports nomadic and mobile clients on the go (IEEE e, 2004)

MAC layer Manage the resources of the air-link efficiently and provide Quality of Service (QoS) differentiation for different connections/streams Supporting Point to Multipoint and Mesh network models Performing Link Adaption & ARQ functions Transmission Scheduling Admission Control Link Initialization Fragmentation and Retransmission

Project Objective Verify via simulation the ability of IEEE MAC to handle multimedia traffic having stringent QoS requirements Determine the best scheduling scheme provided by IEEE for multimedia traffic Simulations to be performed on NS-2

Scheduling Services provided by IEEE MAC Classification of applications based on the commonality of: – QoS service requirements (e.g. real time applications with stringent delay requirements, best effort service applications with minimum guaranteed bandwidth) – Packet arrival pattern (fixed/variable sized data packets at periodic/aperiodic intervals) – Mechanisms to send Bandwidth requests to the BS

Scheduling Services provided by IEEE MAC Unsolicited Grant Service – supports real-time applications with strict delay requirements with fixed sized data packets Real-Time Polling Service – supports real time applications with less stringent delay requirements, generating variable sized data packets Non-Real-Time Service – supports applications with no specific delay requirements, reserves a minimum amount of bandwidth Best Effort Service – supports applications with no specific delay requirements – like the internet

Simulation Environment NS 2 Simulator PMP mode Time Division Multiple Access mode for transmission from SSs to BS Downlink and Uplink subframes duplexed using Frequency Division Duplex Full Duplex Subscriber Stations

Traffic Models Voice over IP traffic – Modeled as ON/OFF source with Voice Activity Detection (VAD) – Packets generated only during ON period – Duration of ON/OFF period distributed exponentially Videoconference traffic – MPEG 4 video trace

Performance Evaluation Affect of frame duration on delay Performance comparison of RTPS with nRTPS when they coexist in the same SS Change in delay with the number of SS Analysis of simulation results (More comparisons to be added)

Work accomplished Literature survey Set up of the simulator environment Integration of the WiMAX module in the NS-2 simulator WiMAX module obtained from Netowrks & Distributed Systems Laboratory (NDSL) members, Computer Science and Information Engineering, Chang Gung University, Taoyuan, Taiwan “The Design and Implementation of WiMAX Module for NS-2 simulator” Proceedings from the 2006 workshop on ns-2: the IP network simulator WNS2 '06 ACM Press

Simulator environment

Simulator Environment

Future Plan Implementation the VoIP model Using the video trace as a traffic source Simulations Analysis of Simulations

References 1. Claudio Cicconetti, Alessandro Erta, Luciano Lenzini, and Enzo Mingozzi, ‘Performance Evaluation of the IEEE MAC for QoS Support’, IEEE Transactions on Mobile Computing, VOL. 6, No. 1, January Jenhui Chen, Chih-Chieh Wang, Frank Chee-Da Tsai§, Chiang-Wei Chang, Syao-Syuan Liu, Jhenjhong Guo, Wei-Jen Lien, Jui-Hsiang Sum, and Chih-Hsin Hung, ‘The Design and Implementation of WiMAX Module for ns-2 Simulator’, ACM International Conference Proceeding Series, Proceeding from the 2006 workshop on ns-2: the IP network simulator 3. F.H.P. Fitzek and M. Reisslein, “MPEG4 and H.263 Video Traces for Network Performance Evaluation,” IEEE Network Magazine, vol. 15, no. 6, pp Nov