本文着重研究网络中使用的MAC协议对语音传输过程的影响，以及无线传

感器网络中适用的语音编码算法。本文首先综述了现有无线传感器网络中常用

的MAC协议，对这些协议进行了分析比较。提出了一种新的基于TDMA的MAC

协议VR-TDMA，为了测试提出的协议性能，在NS2仿真平台上对该协议进行

了仿真，结果证明该协议具有良好的实时性能。然后研究了几种常用语音编码

算法的性能，通过比较研究，认为ADPCM语音编码算法的性能符合无线传感

器网络应用的要求，并对该算法进行了简化，减少了算法运行的计算量。实际

测试表明，算法具有良好的性能。

-In this paper,we concentrate on the mac protocols of wireless sensor networks，

especially the impact imposed on speech transmition．We also want to find a speech

coder which is fit for wireless sensor networks．Firstly,we intorduce the existing mac

protocol，such aS IEEE802．1 1，SMAC protocol，TRAMA protocol，DMAC protoc01．

Moreover we analyse and make comparison of them．Secondly，we propose a new

mac protocol named VR-TDMA．Simulation in NS2 proves that this protocol Canhave pleasing performance in real．time application．Thirdly,we

make a comparison

of some famous speech encoders．The result indicates that ADPCM(Adaptive

Di脏rential Pulse Code Modulation)is simpler than advanced low bit。rate VOICe

coding techniques and doesn’t require as heavy caculations．In this work，We simplify

the algorithm in order tO make it fit for the networks beaer．Actual tests prove that

this simplified algorithm work well in wireless sensor networks．