Abstract:The delay of a meshdistributed backbone Wireless Mesh Network (WMN) was investigated. A shortpath routing protocol based on traffic load balance was put forward. Considering the factors of routing protocol, network scale, the serving capability of gateways and mesh routers, the arriving rate of data packets, MMNs queuing delay was researched. In addition, the relation between queuing delay and capacity of the networks was discussed, and then the capacity based on the restriction of delay was given.