A synchronous, reservation based medium access control protocol for multihop wireless networks

We describe a new synchronous and distributed medium access control (MAC) protocol for multihop wireless networks that provides bandwidth guarantees to unicast connections. Our MAC protocol is based on a slotted time division multiple access (TDMA) architecture, with a multi-mini-slotted signaling phase scheduling data transmissions over slots in the following data phase. Resolving contentions at the beginning of a frame allows for effective utilization of bandwidth. Our protocol essentially combines the benefits of TDMA architecture with the distributed reservation mechanism of IEEE 802.11 MAC protocol, thereby performing well even at high loads. We implement a two-way handshake before each data slot to avoid deadlocks, a phenomena that plagues 802.11. Through theoretical analysis, we derive the system throughput achieved by our MAC protocol. We implemented our MAC protocol into ns-2 simulator, and demonstrate its vast superiority to IEEE 802.11 and a synchronous MAC protocol CATA through extensive simulations.