Research Of Adaptive Routing Protocol For TDMA MANET

All nodes in Mobile Ad Hoc Network(MANET)are of the same function and do not rely on fixed communication infrastructures.So each node has to be capable of both routing and forwarding for the networking.Due to these characteristics,MANET plays an increasingly important role in military and civilian fields.In order to adapt to the characteristics of the wireless channel,broadband wireless communication technology provides multi-rate transmission capability.The routing algorithms based on minimum hop severely limit the improvement of the network throughput.Furthermore,in the MAC protocol selection of ad hoc network,contention protocols,such as CSMA/CA,cannot provide better Quality of Service(Qo S)guarantee in a MANET when its network load is heavy.By contrast,the allocation protocols,such as TDMA,can more easily satisfy Qo S requirements.Consequently,how to make full use of wireless links' multi-rate transmission capability is a key issue for the Qo S guarantee of real-time services in a TDMA MANET.Based on the TDMA protocol,a cross layer multipath routing protocol(CLMP)and its implementation scheme are proposed in this dissertation in order to improve the utilization of bandwidth and to reduce the delay.For the characteristics of TDMA and multi-rate transmission mechanism,the proposed CLMP introduces a parameter for path evaluation,namely RA,which performs a compromise between the queuing delay and the link bandwidth so as to select the path with high transmission rate as much as possible while reducing the end-to-end delay.In order to make full use of multi-path information,the CLMP divides paths to each destination into an optimal path and multiple alternative paths.Afterwards,through cross-layer interaction,the network layer notifies the MAC layer of the trade-off multipath information so that the MAC layer can combine multipath information during queue scheduling to change the packet routing to increase the probability of frame aggregation when necessary and to improve network throughput by making full use of link transmission capabilities.Finally,the proposed CLMP is simulated on the OPNET simulation platform.Firstly,the optimal solution of RA is obtained through simulation and comparison.Then,simulation experiments are performed in different network topologies and input traffic scenarios to compare CLMP with DSDV in three performance indicators including network delay, network throughput and routing overhead.From the comparison chart in simulation,it can be seen that the CLMP achieves the guarantee of service quality,reduces network delay,and improves link utilization and network throughput by balancing and selecting multiple paths to the destination node.