Oussama Alsabek
Start date: 01/10/2008
Email: oussama.al-sabek@brunel.ac.uk
Supervisor: Dr. R. Nilavalan
PhD Research Title: Congestion Control and Fairness over Wireless Mesh Networks
Fairness is a major issue in wireless mesh networks. The throughput unfairness is a critical problem in wireless multi hop environments where the nearest nodes to the gateway get a higher chance to transmit and receive data, whereas the further nodes get less and less chance to transmit and receive. The unfairness in WMNs is due to mainly two layers mechanisms interacting over a wireless multi-hop network: MAC (IEEE802.11b, for instance) and transport (TCP) layers. Moreover, the contention on the wireless medium among different flows leads to a serious unfairness where the nearest to the gateway get more bandwidth while other flows which are a few hops away may starve. Thus, solutions have been proposed in the literature to accommodate the unfairness issue. Those proposals can be classified according to their functionalities as: Mac layer, network layer, transport layer, or cross layer techniques. Also, some of which is distributed while others are centralized.
In this research, a novel enhancement to an existing technique (ADAM) is proposed. This makes an end-to-end transport-layer technique that not only assures fairness in WMNs, but also improves the throughput for all the active flows that transmit simultaneously to the gateway which is in turn connected to the internet. Fig [1] shows throughput enhancement between 4% - 35% achieved keeping fairness index very good (>=0.9).
Fig 1.a Throughput Enhancement Ratios comparing with ADAM for 2 packet sizes: 128 B, 256 B
Fig 1.b Throughput Enhancement Ratios comparing with ADAM for 2 packet sizes: 512 B, 1024 B
Publications:
- O. Al-Sabek and R. Nilavalan, “A novel technique to enhance throughput and fairness over wireless mesh networks”, in ReSCon '12, Research Student Conference: Book of Abstracts, Abstract Number E-30, Brunel University, 18 June 2012.
