Delay-sensitive routing in multi-rate MANETs
A mobile ad hoc network (MANET) is a collection of mobile hosts, which can communicate by the aid of intermediate mobile hosts without utilizing a fixed infrastructure and centralized administration. Many MANET standards, such as 802.11a, 802.11b, and 802.11g, can be operated at various rates for Quality-of-Service (QoS) constrained multimedia communication to more efficiently use the limited resources of MANETs. Since the radio channel is shared among neighbors in MANETs, calculating one-hop delays and determining delay-sensitive routes using the IEEE 802.11 MAC are still two challenging problems. In this paper, we first exploit the busy/idle ratio of the shared channel to estimate one-hop delay based on varied data rates. Then by the aid of the estimated delay, a multi-rate routing protocol is proposed for selecting data rates and determining a route for admitting a flow with a requested delay. In MANETs, when a host is transmitting data packets, its neighbors are blocked (i.e.,forbidden to send packets) since it shares the radio channel with its neighbors. We adopt the strategy by selecting the combination of data rates and a route in order to minimize the total blocking time to all hosts of the network for maximizing the networks capacity, which is the number of flows admitted by the network. Simulation results show that the proposed method obtains a more precise one-hop delay than a very recent work, and the proposed protocol admits more flows than an existing protocol.
delay routing multi-rate mobile ad hoc networks