Neighbor-Aware Control in Ad Hoc Networks

摘要

Ad hoc networks have very unique features, such as dynamic topologies, relatively limited bandwidth and wireless signal propagation schemes, which present difficult challenges for wireless communication. We propose control mechanisms for channel access scheduling and topology control in ad hoc networks, respectively, which utilize the neighborhood information within two hops to cope with the difficulties of communicating in ad hoc networks. First, we present the neighbor-aware contention resolution (NCR) algorithm, and analyze its generic performance with regard to the contention delay and system throughput. The required neighbor information in NCR for ad hoc networks is acquired through the neighbor protocol, which is based on a random channel access mechanism and a reliable message propagation scheme using retransmissions. Then, four channel access protocols based on NCR are presented, namely NAMA, LAMA, PAMA and HAMA, which correspond to node-, link-, pair- wise- and hybrid-activation multiple access protocols, respectively. These protocols are aimed at ad hoc networks with omnidirectional antennas, and their performance is analyzed. Furthermore, channel access protocols, adapted from NAMA and PAMA, are considered for heterogeneous ad hoc networks that include unidirectional links, which may occur due to power and signal propagation differences between wireless stations.