Abstract
Ad Hoc networking allows portable devices to establish communication independent of a central infrastructure. The issue of routing in a mobile ad hoc network becomes a challenging task since the mobile nodes are free to move randomly. Quality of Service (QoS) is the performance level of a service offered by the network to the user. Most of the multimedia applications have stringent QoS requirements that must be satisfied. The goal of QoS provisioning is to achieve a more deterministic network behavior, so that information carried by the network can be better delivered and network resources can be better utilized. A service can be characterized by a set of measurable pre-specified service requirements such as minimum bandwidth, maximum delay, maximum delay variance and maximum packet loss rate. However, many other metrics are also used to quantify QoS. This paper classifies QoS routing protocols based on topology, route discovery with QoS mechanism, interaction based between network and MAC layer, QoS metrics based, and type of QoS guarantee.