Title: Cooperation at the Medium Access Control (MAC) Layer
Speaker: Shivendra Panwar (joint work with Jeffrey Tao and Pei Liu) 2:20-2:40

ABSTRACT

The broadcast nature of wireless communications implies that a source signal transmitted towards the destination can be overheard by neighboring nodes. Cooperative communications refers to processing of this overheard information at the surrounding nodes and the retransmission towards the destination to create spatial diversity, thereby obtaining higher throughput and reliability. Conventional wireless systems are designed and optimized in such a way that any unicast message involves two parties only. To fully leverage the concept of cooperation, the entire protocol stack, from physical layer to networking protocols, should be carefully reengineered or even redesigned.

This talk focuses on the design and evaluation of a particular cooperative MAC protocol, which is backward-compatible with the current IEEE 802.11 standard. The new MAC leverages the multi-rate capability provided by IEEE 802.11, allowing the mobile stations far away from the access point to transmit at a higher rate by using an intermediate station as a relay. The advantages of cooperation at the MAC layer in terms of throughput, delay and energy savings will be demonstrated by simulations, analysis and testbed results.