MAC Enhancement to Support Quality of Services (QoS) in Ad Hoc Wireless Networks: EMACA (Enhancement of Multiple Accesses with Collision Avoidance)

An ad hoc wireless network (AWN) is a collection of mobile hosts forming a temporary network on the fly, without using any fixed infrastructure. Characteristics of AWNs such as lack of central coordination, mobility of hosts, dynamically varying network topology, and limited availability of resources make QoS provisioning very challenging in such networks. QoS (Quality of Service) is the idea that transmission rates, error rates, and other characteristics can be measured, improved, and to some extent guaranteed in advance. QoS is of particular concern for the continuous transmission of high bandwidth video and multimedia information. Transmitting this kind of content dependably is difficult in public networks using ordinary "best effort” protocols. Ad hoc wireless networks (AWNs) are zero configurations, self organizing, and highly dynamic networks formed by a set of mobile hosts connected through wireless links. MAC (Medium Access Control) Protocols provides the access control for transmission. The designing issues are Bandwidth efficiency, Quality of service, Synchronization, Hidden and exposed terminal problems, Error-Prone Shared Broadcast Channel, Mobility of Nodes and Distributed Nature/Lack of Central Coordination for Ad Hoc wireless networks. MACA (Multiple accesses with Collision Avoidance) Protocol is a Contention based protocol. MACA does not