Research On Carrying Out Mobile IP Phone Using VoIP Mixed With WLAN Technology

This thesis mainly discusses the system design and realization which using VoIP mixed with WLAN technique. It carries on research from the system structure, network layer, commuication protocol, related audio encode/decode tecnnology, as well as the function realization and quality assurance of each module.VoIP and WLAN techniques develop quickly in the recent years. VoIP delivers data through the Internet to cut down the phone cost. WLAN transports data form the air, simplifying the construction of network. This thesis simply introduces the VoIP and WLAN relavant technique and standards, containing audio technology, the series standard of IEEE 802.11, etc. And mainly gives detail explanation of the two key techniques: QoS of VoIP and the security transmission of WLAN.This thesis emphasizes on the design of the terminal equipment of mobile IP phone system, that is the WiFi phone, under the mode of ISP. It describes the WiFi phone from the network structure, logic design, framework of the key equipment, model realization to the equipment function in detail. Also , it does a lot of test work with the WiFi phone, such as the function test ,the guide line analyze, for the purpose of verifying the possibility of the project.In our country, the VoIP application restricts to PC-to-PC. There is no Phone-to-Phone ISP at present. According to this, this thesis suggests a method of carrying out mobile IP phone system at the enterprize level, basing on the realization of the WiFi Phone, and using the VoIP audio gateway product. Make use of the original resource of the enterprize, combine internet with the traditional PSTN net, as to deliever data freely between the two nets, improve the utilization of internet, optimize the resource configuration. As the result of this method ,the enterprize could reduce it's cost on the long-way telephone calls .