A Distributed Channel Access Protocol for Ad Hoc Networks with Feedback Power Control

Distributed power control schemes are extensively employed in the cellular networks and are capable of improving the capacity of the network. However, the power control schemes from the cellular networks suffer from performance degradation due to self and direct-interference and hidden-terminal problems when directly employed in ad hoc networks. Most of the existing channel reservation-based power control protocols for ad hoc networks employ incremental power allocation rather than global allocation of the power to the incoming links; thus, they may not effectively utilize the spatial frequency reuse in the network. This paper presents a distributed channel access protocol that couples the channel reservation and the iterative/global transmission power control schemes in ad hoc networks. The designed protocol considers the convergence problem of the global power control in ad hoc networks. The designed access criteria employ the local admission control based on the sufficient criteria for admissibility and global power control for balancing the SIR (signal to interference ratio) of the links. In the performance evaluation study of the designed protocol, an almost twofold increase in the throughput and capacity is observed compared to the existing power-controlled protocol for ad hoc networks.