Abstract: To address the routing problem in the UAV swarm network,the OLSR protocol announces Hello and Topology Update(TC) messages in the form of fixed period to maintain network topology information.However,in the case of frequent changes in network structure,such periodic announcements cannot respond to changes in the network topology in time,resulting in significant network performance degradation.This paper proposes a new cluster-based optimized link state routing protocol(CB-OLSR),which is composed of intra-cluster and inter-cluster routing.CB-OLSR dynamically adjusts the broadcast cycle of Hello and other control messages according to the network topology changes,so as to update the network status in time and obtain better network performance.At the same time,the short and direct connection path within the cluster is optimized.If the source node and target node are neighbors within two hops,the hierarchy structure is ignored and bypass shortcut is used to forward message directly,so as to reduce the load on the cluster head and extend its life.Through the simulation experiment on EXata simulation platform,the results show that CB-OLSR is significantly better than OLSR in terms of data packet loss rate and throughput,so it is more suitable for UAV swarm network.

Key words: Network topology, OLSR, Period, Routing protocol, UAV