Research On Topology Management And QoS In Wireless Ad Hoc Networks Based On Location Information And Topological Construction Analysis

A wireless Ad Hoc network is a self-organized communication network with some nodes equipped with wireless transmitters and receivers based on multi-hop, it is an important part of the future wireless communication networks. Compared with traditional communication networks, the wireless Ad Hoc network needs no current network infrastructure. It shows many features such as flexible networking, anti-destroy and the development and application of this kind of networks are very promising not only in military but also in commercial areas. This thesis focus on the the analysis for wireless Ad Hoc network based on the lacation information of the nodes and the performance of topological space and to seek the the optimized network topology construction scheme and perform the research on QoS within the topology analysis.The multi-hop feature of the wireless Ad Hoc network makes it impossible for using the routing protocols of infrastructure networks, but considering the dynamical of the topology, limitation of the transmitting band and the unidirectional links, the routing protocols can not be used immediately. The topology of the wireless Ad Hoc network will be changed rapidly along with the moving of the nodes, so the routing protocols of infrastructure networks can not give the topology information of the networks in time. What's more, it will waste much band to distribute the control information which maintains the topology to the network. This thesis modified the routing protocols in wireless Ad Hoc network based on the location information, and improved the network performance in special scenarios with the help of the intergration of the routing protocol and location information. The analysis and discuusion about the TCP stability and the peer-to-peer problem such as routing connectivity, maximum of frame, unsymmetry and stability in wireless Ad Hoc network can induct the problem about the improvement of wireless Ad Hoc network's TCP stability based on location information. The topology of wireless Ad Hoc network can be denoted by the transmitting power of each node, the unconnectivity and interference will occur when the power is too high or too low. The topology which can not only realize the network connectivity but also minimize the power consume and interference should be computed by the research on the information distribution and the usability of different topologies. There are two ways to analyze topology control. Let the radius of the nodes is in fixed value, the minimized value of the interference can be given with the help of space restriction of the node's location, the optimized performance can be acquired by using relative neighbor gragh. Thisthesis analyzed the performance improvement problems based on two topologies and optimized LDM algorithm, enhanced the throughput and other performances for linear topology and dual ring topology, and reduce RTT of the network on the same time. The optimized topology of the network which can ensure QoS can be founded with the help of the location information of the nodes. The QoS routing, the power efficiency of QoS topology control, the minimized power consume and the optimization of the topology control should be analyzed based on the conditions in both splitable and unsplitable of the flows. This thesis lucubrate the above problems and give the main contributions shown below:1. Due to the randomly moving of the node and the randomly changing of the topology, it is difficult to token the characters of the wireless Ad Hoc networks by using the traditional routing protocols. Based on the location information, this thesis proposed a new modified scheme for DSR protocol and put it into the special scenarios. The simulation results shown that the modified scheme is more efficient.2. The analysis for TCP stability of wireless Ad Hoc networks in this thesis shown that the TCP stability is worse than other networks because of the characters of this kind of networks. The thesis gave a new method to improve the stability of TCP based on the location information.3. This thesis analyzed the affection of the information distribution by using the topologjcal replace method about transmitting power of the nodes and acquired the optimized topology which can not only ensure connectivity but also minimize the power consumption by using relative neighbor graph and other ways. The simulation results shown that the new method is more stability for node radius, node degree and other issues.4. Based on the provement of the topological spaces and attributes, this thesis analysis the performance of the hybrid network. It is based on two topologies: linear topology and dual ring topology. A new scheme for LDM algorithm, called M-LDM algorithm, is given. Because of each parameter for nodes and TCP flows are all represented in M-LDM and recurrence optimization is used, the new scheme can improve the throughput, reduce the packet loss rate and RTT, so the reliability and the efficiency of the network are all improved.5. This thesis analyzed the optimized topology for QoS by using the attributes of the links and networks, and intergrated the location information in splitable and unsplitable for flows. Discussed the QoS problem in special network topology, the power efficiency for QoS topology control algorithm, minimize energy consume of the network nodes and topology optimization. The results shown that the flow demand and maximum hop number can all be improved with the help of the location information. When the flows can be splitable, the simulation results for hop number are better than unsplitable conditions because of the more efficient denote for the network's routing parameters.