The Study Of QOS Routing Protocol Based On Opportunistic Networks

In recent years, a large number of low-cost, short-range wireless communication devices appeared, which promoted the rapid development of opportunistic networks. The opportunistic networks are similar to mobile ad hoc networks. Nodes move randomly so that links frequently are interrupted which results in constantly change of network topology. Thus, it is difficult to establish an end-to-end complete path. In MANETs, multipath routing protocols have been widely used to improve the path stability, but the multipath routing protocols in opportunistic networks have not virtually been taken application into consideration. Therefore, we use multipath routing protocols and match condition of QoS constraints to improve stability. This research attracts extensive attention from scholars.Combined the corresponding multipath routing protocols in MANETs with the characteristic of opportunistic networks, the thesis proposes two kinds of QoS routing protocols:reliability node based multipath routing (RNMR) protocol and backup path QoS routing (BPQR) protocol. In order to valid the performance of them, the thesis uses mathematical method to achieve Cumulative Distribution Function (CDF), which describes the path lifetime of RNMR protocol and BPQR protocol. Through further calculation for the expectancy of the path lifetime, we can judge the stability of the path. Moreover, through the theoretical analysis and performance validation for the two protocols, the results showed that, under the condition of various lengths of the primary path, their path lifetime are all improved; the stability of the path is enhanced; and packet loss rate from source to destination is reduced. Thus, the QoS of the network is guaranteed at the same time. The study of multipath QoS routing protocols in the thesis laid a solid foundation for both the selection of stable path and improvement to QoS in the opportunistic networks.