The Research Of Optimization Of Energy Efficiency Of Link Collaborations In Mobile Multi-hop Wireless Networks

With the development of new information technologies, mobile multi-hop wireless networks have become an important networking mode of next-generation wireless networks. Mobile multi-hop wireless networks have such features as quick deployment, strong expansibility, flexible networking, convenient access and so on, however, their network topology dynamically change over the mobile nodes, and are often equipped with limited energy for specific application, how to build a high energy-efficiency multi-hop networks in a dynamic time-varying mobile network environment has then become an important issue. Improving network energy efficiency can make nodes transmit more information with less energy, thus achieving the goal of communication quality insurance and reducing system power consumption. In the meanwhile, it can improve system efficiency and system performance. This thesis use Links collaborative to optimize the energy efficiency in mobile multi-hop wireless networks and design the corresponding energy-efficient routing algorithm.The thesis firstly studies the energy-efficient routing protocols of collaborative links. The routing protocol with high energy efficiency is one of those important methods to reduce the energy efficiency of mobile network. A simple and highly effective routing protocol can make sense of the changes of the network topology, find out the routes quickly and correctly and then update the link state, maintain the connection of network topology dynamically. In recent years, the researchers have made large numbers of studies about that, however, they caused plenty of energy consumption since many models among the designs are not delicate enough in which they achieve the goal of energy efficiency by altering routes directly and ignore the cost caused by the alteration. Under the system of 802.11 DFC, the thesis carefully designs the scheme for route discovery and maintenance. The route discovery scheme has low cost and fast speed; while the route maintenance scheme is able to built routes with high energy efficiency with the lowest cost by the means of collaborative links. The simulation results show that the energy-efficient routing protocols of collaborative links proposed by our thesis can significantly improve uplift network energy-efficiency.The thesis then studies the energy-efficient sleeping protocols of link collaborations. By analyzing the energy consumption of different nodes under different working condition, it implies that dormancy is an essential measure to lower energy efficiency of the nodes. Dormancy can not only reduce both the energy consumption of idle monitor and unnecessary overhear, but also can get rid of the conflicts and interferes to a certain extent. For nodes, shutting down their radio frequency, however, will make them unable to sense surrounding communication, and the dormancy will result in larger multi-hop delay such that the throughout is lowered under heavy loads. So we need to solve the coordination and synchronize problem. The thesis combine the three aspects of route protocols, dormancy scheme and synchronization together, divide the dormancy scheme into two parts, namely, dormant when there are nodes occupying channels and synchronous dormancy based on average channel idle time when channels are idle, and then achieve nodes' dynamic dormancy of mobile wireless network. Simulation results illustrate that the energy-efficiency dormancy protocols of collaborative links can significantly reduce the network energy consumption, raise network energy-efficiency and reduce the delays brought about by dormancy.At the end of the thesis, we make research about the rate self-adaptive algorithm of collaborative links. In a network with changeable rate, the link bandwidth varies when using different sending power to send data. When the sending rate varies, the energy consumed by receiving nodes when they receive per bit data in the case of ideal bandwidth and received SNR will change correspondingly. The selected transmission strategy, position together with selected sending rate of each node will determine the network performance. Of course, the energy efficiency will be different is the case of different sending rate. In the mobile multi-hop wireless network, there exist multi links between origin nodes and destination nodes, proper coordination on nodes' sending rate and sending power of the path is a critical means to improving the whole network energy efficiency. The transmission strategy in our thesis is to maximize the whole network energy efficiency by coordinating the sending rate among links under the condition that the nodes in multi-hop links have the same sending rate. The simulation results indicate that rate self-adaptive algorithm of collaborative links is capable of increasing the whole network energy-efficiency.