Hybrid Channel Access Scheduling in Ad Hoc Networks

Download or read book Hybrid Channel Access Scheduling in Ad Hoc Networks written by and published by . This book was released on 2002 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the hybrid activation multiple access (HAMA) protocol for ad hoc networks. Unlike previous channel access scheduling protocols that activate either nodes or links only, HAMA is a node-activation channel access protocol that also maximizes the chance of link activations using time- and code-division schemes. HAMA only requires identifiers of the neighbors within two hops from each node to schedule channel access. Using this neighborhood information, each node determines whether to transmit in the current time slot on a dynamically assigned spreading code. A neighbor protocol supplements HAMA with up-to-date two-hop neighborhood information by reliably propagating the one-hop neighbor updates through a novel random access technique. The throughput and delay characteristics of HAMA in randomly-generated multihop wireless networks are studied by analyses and simulations. The results of the analyses show that HAMA achieves higher channel utilization in ad hoc networks than a distributed scheduling scheme based on node activation, similar throughout as a well-known scheduling algorithm based on complete topology information, and much higher throughout than the ideal CSMA and CSMA/CA protocols.