Research On The Quality Evaluation For Voice Over MANET

In recent years, the thechnique of VoIP (Voice over Internet Protocol) has developed rapidly and has become increasingly popular in both wired and wireless single hop networks. In some special application environment, such as that required for fast deployment of military forces in unknown and hostile terrain, rescue operation after an earthquake or flood the wired and wireless single hop networks are not suitable. For such environment, a special type of communication network which works without the use of any existing network infrastructure, and in which nodes are free to move randomly and organize them arbitrarily is required. This requirement leads to the emergence of a new type of network, called Mobile Ad Hoc Networks. It is of great practical significance to implement VoIP framework on MANET.But due to the characteristics of MANET, implementing VoIP services and guarantying its voice quality are faced with many challenging issues. With this motivation, this thesis explores these challenging issues and proposes a first step solution in resolving them. First, this thesis sets up an application scenario for voice over MANET, and a quality evaluation model is proposed based on E-model with extention. In this evaluation model, characters such as, network state, medium access scheme, routing protocols, are mapped to the score which can express the quality of voice. Inorder to tesify the valid of this model, a verification model is designed. Through the software of netwok simulation, this thesis uses this model to evaluate the quality of voice.Beased on the result of simulation, the model proposed by this thesis is simple and valid. It can roughtly compute the characters of MANET to the factor of voice quailty. The verification model designed can be used as a evaluation scheme in implementation the voice communication between Mobile Ad hoc Network and Internet. Also, it provides a standard to design and select the medium access protocol, routing protocol and cross-layer design to meet the requirement for voice over Mobile Ad hoc Network.