关键词: 无线传感器网络, 实时数据, 尽力而为数据, 区分服务, 时延, 能耗均衡

Abstract: Aiming at the different QoS requirements for various traffic transmission level in wireless sensor networks，a differentiated services algorithm for various traffic transmission has been introduced—EMHNS.The algorithm chooses appropriate forwarding nodes based on various traffic transmission levels.So it can achieve the minimum time delay for real-time traffic transmission.The influence of delay is not the primary factor for best-effort traffic transmissions，the network energy load balance should be taken into account heavily when the best-effort traffic transmits.The simulation results indicate that this algorithm can achieve lower time delay for real-time traffic than Directed Diffusion （DD） algorithm，and extend the lifetime of the network.

Key words: wireless sensor networks, real-time traffic, best-effort traffic, differentiated services, time delay, energy load balance