The Research And Improvement Of Location-based Dynamic Source Routing Protocol

Mobile Ad Hoc Network (MANET) is widely used in military, agriculture, environmental monitoring, medical and health, industrial, AI transportation, buildings monitoring, outer space exploration etc. It is regarded as one of the world top 10 technologies in the future, as well as an important member technology of object-internet. The study of the design or optimization of more efficient network protocols for the Mobile Ad Hoc Network (MANET) to extend the network lifetime and improve its performance, such as packet delivery rate of success, speed, etc. has became more and more popular.In this thesis, a detailed analysis of the DSR (Dynamic Sourcing Routing) routing protocol is carried out. As a classical on-demand MANET routing protocols,its protocol specific algorithm is divided into two phases:route discovery phase and route maintenance phase. The first phase of the standard DSR protocol is route discovery phase. At this stage the source mobile node sends a route request packet(RREQ) by the plain RREQ flood over the entire network, so that the limited bandwidth in MANET has been greatly used in the flood route request packets that takes down the throughput of the network. To solve this problem, the DSR protocol is optimized in the thesis by introducing a mechanism, which adopts flooding within a limited radius and determining the optimal next hop relay node according to the inter-region location of the limited radius. In the first phase,the so called "the best next hop node" in which the source node choicses a transit node to the destination node by looking away from the location of the nearest neighbor to the destination node, the strategy is used for the choice of route discovery process, and each node maintains a link-state table within a radius of limited hops called local link list. This local link table records the link state of the nodes within limited hops from this node timely. Thus,the overall networks adopts the thoughts that using routing cache to record the topological structure in the global scope and link cache in the local scope. To implement these ideas, a few key concept data structures are added and the improved algorithm processes ard discussed, as well as the specific response processing steps when each node receives a route request packet(RREQ) or a route reply packet(RREP).As to the aforementioned two modification,this paper has extendedly installed standard DSR and implements based on the NS2 simulation network platform.According to the many comparative analysis experiments of the improved GDSR(Geography DSR) and DSR. In order to guarantee the accuracy of the results, many different movement scene distribution file simulations are generated. The results show GDSR indeed effectively improve the overall network throughput and the average end to end delay, so that it improve the network performance. The results also show that the GDSR protocol (based on geographic location to select the routing node) is feasible, but the specific implementation aspects still need further refinement, and some details of the GDSR protocol should be further improved...