The Voip Software Development Based On Android Platform

With the development of science and technology, the cost of electronic product has been declined continuously, and people’s life is greatly evolved in intelligent terminal, which has become the indisp ensable tool in people’s daily work and study. Based on the concept of opening and mutual benefit, Android system occupied the most proportion of intelligent terminal market rapidly through open source and played an important role gradually. Regarding the good application prospect of Android system, Android platform is chosen as the implementation platform in this topic.Based on constant improvement of technologies on the terms of telephone signaling, network, multimedia, speech coding and network penetrat ion and the fast growth of internet application at the same time, network telephone has developed rapidly depending on good technology and wide application market in recent years and started to replace the traditional telecom network communication more and more in our life. This paper is aim to research the design of VOIP software implement based on Android system. The development of communication software with practical value has substantial significance for library in the following extension in the field of smart home.This system is composed of client and server. Client mainly including three modules, such as, speech signal processing & transmission, telephone signaling SIP and network penetration. Server is mainly used to complete the function of user online registration, addressing between users and user registration. The main content of this paper is as follows :Implement of speech signal processing and transmission process, which includes the speech signal collection, coding, sending, receiving, decoding and displaying, each part is accomplished by separate thread as following: First, collect the voice signal data by utilization of Android platform and send them to ILBC for encoding. Second, deliver the decoded speech data to sending thread and transfer to the specified address through socket technology. Third, monitor the speech data by receiving thread at specified terminal port based on socket technology and deliver the received data to decoding thread for encoding. Finally, broadcast the decoded data immediately by playing thread.Implement of SIP signaling on the client. Develop SIP signaling client by use of API equipped by Android system. Registration and preservation of users’ information, making and receiving calls are the basic function of client.Implement of basic function server of SIP. By utilization of open source server code, SIP call server was set up and the software interface for user management was developed based on such server, which in turn achieved the function of easy registration and cancellation for user.A good processing and transmission of speech signal has been completed after practical test, the voice quality in local area network is very clear and it seems that there is almost no delay. SIP client not only accomplished the login of SIP server, but also enable to create SIP call to the specified SIP user, while the server achieved the registration and logout process for user.