Rate Adaptation and Resource Allocation for IEEE 802.11 WLANs

PhD Thesis Proposal Defence


Title: "Rate Adaptation and Resource Allocation for IEEE 802.11 WLANs"

by

Miss Qiuyan Xia

Abstract:

IEEE 802.11 Wireless Local Area Networks (WLANs) have become increasingly
popular due to the recent availability of affordable devices providing
multi-rate capabilities. In this proposal, we study rate adaptation and
resource allocation methodologies for 802.11 WLANs. Rate adaptation is a
key functionality in WLAN devices to cope with time-varying channel
conditions and maximize the throughput of a point-to-point wireless link.
We propose a novel rate adaptation algorithm, "Smart Sender", which
utilizes both statistics and signal strength measurements to select the
transmission rate that maximizes the link throughput. We also implement
and evaluate the algorithm in commercial WLAN devices, which prove that
Smart Sender is fast-responsive, of low-overhead, and robust to collision
errors in various wireless environments.

While rate adaptation exploits the multi-rate capability of an individual
user, it also results in the well-known phenomenon of "performance
anomaly" among multiple rate-different users sharing the WLAN. Hence,
efficient resource allocation among these users is critical to the system
performance. For downlink resource allocation, we develop a weighted fair
scheduling based on adaptive rate control (WFS-ARC) framework for
throughput optimization while satisfying the temporal fairness. For
resource allocation with TCP flows in a WLAN, we design a dual queue
management (DQM) scheme for TCP congestion avoidance and uplink/downlink
fairness provisioning. DQM also exploits opportunistic scheduling for high
link efficiency.

For future work, we will study rate adaptation and resource allocation
methodologies for IEEE 802.11n WLANs and Vehicular Ad hoc Networks
(VANET). We believe the approaches discussed in this proposal could
contribute to future research on next generation wireless networks,
providing a versatile and flexible structure for various systems.


Date:     		Wednesday, 30 January 2008

Time:                   2:00p.m.-4:00p.m.

Venue:                  Room 3501
			lifts 25-26

Committee Members:      Prof. Mounir Hamdi (Supervisor)
			Dr. Brahim Bensaou (Chairperson)
                        Dr. Gary Chan
			Dr. Qian Zhang


**** ALL are Welcome ****