Efficient Distributed Medium Access Arbitration for Multi-Channel Wireless Sensor Networks

Wireless sensor networks can be employed in a wide range of applications such as disaster management, combat field surveillance and homeland security. Sensors in such applications are deployed in mass and are usually constrained in the amount of available onboard energy. This paper presents ARCH, a distributed medium access arbitration of multi-radio-channel based sensor networks. ARCH is an energy efficient, scalable and collision free MAC layer protocol that combines frequency and time division principles for medium sharing. To achieve scalability sensors are partitioned into cells. One of the sensors in a cell is designated as a cell-head. ARCH employs a distributed algorithm for arbitrating channels among cells to enable simultaneous non-interfering data collection. Intra-cell transmissions are scheduled by the cell-head using the assigned channel. Cell-heads aggregate the gathered data and forward it over inter-cell-head paths to the base-station. The base-station assigns distinct channels to the independent branches of the inter- cell routing tree. Data transmission and reception on a branch is further scheduled in depth-first ordering. ARCH allows nodes to stay in the sleep mode for the longest duration and avoids collisions and thus it minimizes energy consumption and boosts the robustness of the network operation. The performance of ARCH is validated through simulation.