Research On Self-healing Routing Technology In Wireless Mesh Networks

With the development of Mobile Internet Technology, there still exist network coverage blind area and insufficient access ability of hot spot region in wireless communication networks. As one of the extension technologies of Mobile Internet technology, WMN(Wireless Mesh Network) has the characteristics of self-organizing, flexible networking, convenient access and strong robustness. Due to such characteristics, it can provide users with access and transmission function in order to solve the insufficient access problems. So, WMN has become a kind of effective mobile communication solution. However, because of the wireless channel instability, link break problem always occurs through data transmission which leads to bad routing performance. It also put forward higher requirements and greater challenges for the research of robust and stable Mesh Network. Therefore Research on self-healing routing in WMN has the vital significance.After an in-depth analysis of the low performance problem existed in self-healing routing research, the article gets the idea that network self-healing should firstly use the backup restoration method, and secondly use the passive restoration as a supplement. In this paper,the self-healing routing research are studied on the basis of reactive and hybrid routing mechanism separately.Firstly, the article uses the HWMP-R reactive routing as baseline to design a fast self-healing routing algorithm---HWMP-RFRR(HWMP-Reactive Fast Restoration algorithm), HWMP-RFRR designs a BackupPath handshake mechanism and a detection mechanism in supplementary repair process. Moreover, the establishment of bidirectional routing in the data transmission process has great benefits to solve the problem caused by the unidirectional routing. The algorithm is useful to avoid invalid backup routing as well as routing loops, also improve restoration quality, to some extent.Secondly, the article designs a Hybrid Centralized Backup Routing Protocol(HCBRP) which combines the advantages of proactive and reactive mechanism, and calculates the optimal routing and node-disjoint suboptimal backup routing in root. This centralized mechanism assures that external transmission can use the Root-Routing as backup routing, and intra-transmission can use the node-disjoint suboptimal routing as backup routing in order to solve the current routing failure problem. HCBRP algorithm has those advantages:low-cost routing overhead, the seamless backup routing switch, low packet loss rate and the global optimal routing/backup routing.Finally, the article simulates the two type self-healing routing algorithm in NS-3 platform. Through multiple experiments, it indicates that HWMP-RFRR algorithm has superior performance especially in low-speed circumstance. In PDF performance, HWMP-RFRR has a 4%-8% improvement compared with HWMP-BR. In restoration time performance, HWMP-RFRR has 18.5% decrease compared with HWMP-R. Moreover, comparing with the traditional HWMP routing, the performance of the HCBRP routing increases significantly not only in inter-transmission circumstance but also in intra-transmission circumstance, and its average performance improvements in PDF/Delay/Overhead are more than 10%, especially in link-break circumstance.