Collision Avoidance and Resolution Multiple Access for Multichannel Wireless Networks

We introduce and analyze CARMA-MC (for Collision Avoidance and Resolution Multiple Access MultiChannel), a new stable channel access protocol for multihop wireless networks with multiple channels. CARMA-MC relies on the assignment of a unique channel and a unique identifier to each node to support correct deterministic collision resolution in the presence of hidden terminals. CARMA-MC dynamically divides the channel of each node into cycles of variable length; each cycle consists of one or more receiving periods and a transmission period. During the receiving period, stations with one or more packets to send compete for the right to acquire the floor of a particular receiver’s channel using a deterministic tree-splitting algorithm. Each receiving period consists of collision resolution steps. A single round of collision resolution (i.e., a success, and idle or a collision of control packets) is allowed in each contention step. The receiving period is initiated by the receiver and takes place in the channel assigned to the receiver station. The channel utilization and packet delays are studied analytically and by simulation.