PhD graduated
Team : Phare
Departure date : 02/01/2009

Supervision : Guy PUJOLLE

Performance evaluation and optimization in IEEE 802.16

IEEE 802.16 is a suite of emerging standards that bring the wireless and broadband access together to fulfil the demand of broadband service anytime and anywhere. IEEE 802.16 standards suit defines a reservation-based bandwidth allocation mechanism. In the mechanism, two main polling modes, the unicast polling mode and the contention-based polling mode, are defined. The different adoption schemes of the polling modes result in different configuration of PHY frame structure and then deeply affect the performance. There should be an optimum scheme to adoptthese two polling modes to optimize the performance. The IEEE 802.16 standards do not specify exactly such a scheme. We investigate the polling modes in IEEE 802.16 networks, and propose a simple but efficient polling mechanism to adopt these two polling modes efficiently and fairly and then optimize the performance. In IEEE 802.16 networks, the contention-based polling mode is used by the contention-based and delay-tolerant applications such as nrtPS and BE to competitively request plink bandwidth. The amount of bandwidth allocated for contention-based request will significantly influence the performance. We analyse and develop a simple mathematical model to evaluate the performance in IEEE 802.16 networks. An optimal contention-request period in the frame is presented. This optimal size is also influenced by the number of terminals in the network, which is also analyzed in the latter. The simulation results verify that our proposed optimal polling scheme can allocate bandwidth more efficient and achieve better performance.

Defence : 01/20/2009 - 17h - Site Passy-Kennedy - salle 550

Jury members :

M. Guy PUJOLLE, Professor of Université Pierre et Marie Curie (Advisor)
Mrs. Monique BECKER, Professor of TELECOM SudParis (Reviewer)
M. André-Luc BEYLOT, Professor of ENSEEIHT (Reviewer)
M. Serge FDIDA, Professor of Université Pierre et Marie Curie (Examinator)
M. Ye-Qiong SONG, Professor of INPL (Examinator)
M. Pierre EISENMANN, Chief Operating Officer of N2NSOFT (Examinator)

2007-2009 Publications