Design and Implementation of IEEE 802.11 Based Dual Media Access Control for MANETs

Mobile ad hoc networks (MANETs) are useful in environment where fixed network infrastructure is unavailable. To function normally, MANETs demand an efficient and distributed medium access control (MAC) protocol. However, characteristics of MANETs such as radio link vulnerability, mobility, limited power pose great challenges on MAC design. In the IEEE 802 reference model of computer networking, the medium access control or media access control (MAC) layer is the lower sublayer of the data link layer (layer 2) of the seven-layer OSI model. Changes are needed at various levels of the protocol stack, most importantly at the medium access layer(MAC).The medium access mechanism in multihop wireless networks should minimize collisions, and take care of the hidden and exposed problems. This chapter deals with the problem of designing and effectively utilizing wireless communication channels. Since the wireless medium is inherently a shared resource, controlling channel access becomes a central theme that determines the fundamental capacity of the wireless network and has a dramatic impact on system complexity and cost. Therefore, our primary focus will be the design and implementation of Media Access Control (MAC) protocols for mobile wireless networks. This work discusses architecture and working of the dual MAC. Performance results of the network using MAC are presented, and compared with that of pure DCF operation.