Abstract: Since the large-scale wireless multi-hop ad hoc networks have been widely used in military communications, emergency communications and other fields, the zone routing protocol (ZRP), as a hybrid routing protocol, has been paid more attention in the large scale network application because of its more flexible routing discovery and maintenance strategy. The selection of intrazone routing protocol and interzone routing protocol of ZRP has great impact on the overall protocol performance. An improved zone routing protocol based on the traditional ZRP framework is proposed for large-scale wireless multi-hop ad hoc network that has certain topological changes. In the improved protocol, the intrazone routing protocol uses a more effective and less resource consumption routing strategy, and the interzone routing protocol uses an expired routing cache mechanism to reduce network overhead. The modeling and analysis results show that the improved routing protocol has higher validity. It is verified through NS2 simulation that the improved protocol has better performance. Key

Key words: communicationtechnology, wirelessmulti-hopadhocnetwork, hybridroutingprotocol, protocolperformance