Abstract:QoS routes searching in tactical MANETs is a NP-complete problem, to which the ant-colony optimization algorithm is an effective solution. To improve the efficiency of ACO based QoS routing algorithms, an ant-colony optimized QoS routing algorithm (MTS-AQRA) based on multiple transferring strategies was proposed. MTS-AQRA integrates link’s stability and route’s congestion into conventional QoS requirements in the process of routing. By utilizing the diversity of route-search ants and the concurrent route-searching result from the multiple transferring processes, MTS-AQRA can work rapidly and effectively to establish stable routes which satisfy the QoS requirements of certain services. Simulation results show that MTS-AQRA outperforms AODV, QoS-Aware ACO and AntHocNet in terms of packet delivery ratio, end-to-end delay, end-to-end throughput and route stability.