To date, the majority of ad hoc routing protocol research has been done using simulation only.

INTRODUCTIONInfrastructured IEEE 802.11b networks are becoming ubiquitous. These networks offer high bandwidth wireless connectivity well-suited for a variety of traffic types, including multimedia distribution. One drawback of infrastructured networks is the complexity of deploying and configuring these networks. Ad hoc networking protocols do not suffer from this limitation. By using a multihop ad hoc network connectivity is maximized.For quality multimedia sessions, routing paths between nodes in an ad hoc network must be continually monitored. Numerous ad hoc routing protocols [1,3,4,7,12] make use of periodic broadcast messages to determine local connectivity. Also, because of the difficulty of obtaining IEEE 802.11 feedback about link connectivity in real networks, many current protocol implementations utilize hello messages [2,3,6,9,10].The basis of using hello messages to determine connectivity stems from the assumption that reception of a hello message indicates a viable communication channel with the source of the hello. This mechanism works well on wired networks, which experience few packet losses and connectivity changes. However, when used in wireless ad hoc networks the effectiveness decreases due to many factors. Some of the factors that have significant effect are: hello loss settings, hello packet size and 802.11b packet handling.

Traditional approaches to guarantee quality of service (QoS)

In this paper AODVjr, a simplified version of the AODV protocol, is described. AODVjr is compared in simulation to a full featured AODV implementation. The results show that AODVjr performs as well as AODV and describes other positive effects of a smaller protocol specification.

Admission control of flows is essential for providing quality of service in multihop wireless networks. In order to make an admission decision for a new flow, the expected bandwidth consumption of the flow must be correctly determined. Due to the shared nature of the wireless medium, nodes along a multihop path contend among themselves for access to the medium. This leads to intra-flow contention; contention between packets of the same flow being forwarded at different hops along a multihop path, causing the actual bandwidth consumption of the flow to become a multiple of its single hop bandwidth requirement. Determining the amount of intra-flow contention is non-trivial since interfering nodes may not be able to communicate directly if they are outside each other's transmission range. In this paper we propose two methods to determine the extent of intra-flow contention along multihop paths. The highlight of the proposed solutions is that carrier-sensing data is used to deduce information about carrier-sensing neighbors, and no high power transmissions are necessary. Analytical and simulation results show that our methods estimate intra-flow contention with low error, while significantly reducing overhead, energy consumption and latency as compared to previous approaches.