Ieee802.15.4 Wireless Access Voip Gateway Design And Realization

As voice communication is the primary media of communication for human beings, it always plays a very important role from public switched telephone network to the third generation mobile communications. Now the rapid development of Internet makes Voice over IP to be a new choice for communication, which leads strong impact on traditional telecommunications.VoIP is based on a series of other technologies, such as DSP, multimedia, Internet and so on. Besides those advantages such as packet switching, effective utilization of the bandwidth and low cost, VoIP can realize various kinds of value-added services, and combine with multimedia technologies, which is the key reason for its huge prospective market. Although the quality of VoIP telephone is not good enough for the moment, it is paid high attention by the communication practitioners. Many international standard organizations are proposing new related standards, focusing not only on the VoIP telephone itself, but also on the IP multimedia multi-point communication and various kinds of VoIP value-added services.But how to get rid of the space restrict and make it to be a mobile system is the most confused problem of VoIP development. Experts have agreed to combine VoIP and WLAN or Bluetooth technology, and some experiments are still in progress at present. For reasons listed above, a new solution of wireless VoIP is given in this paper.The paper presents a design model and implementation of VoIP gateway under MCF5234 microprocessor and eCos platform based on thorough analysis and research of VoIP technology and IEEE802.15.4. It firstly introduces the correlative technologies of VoIP gateway, including session initiation protocol, IEEE802.15.4 standard and so on. Then it describes the system architechture design of the gateway, and illustrates the implementation in detail, which includes MC13192 driver, the MAC layer of wireless network and the main application.This solution has already been applied and implemented in the wireless VoIP gateway of zigbee phone project. According to the QoS test and function validation test, this system well meets the requirements of IEEE802.15.4 wireless access audio communication. In the end, the paper makes expectations of future work, and points out the method of improvement, which would make the gateway more advanced.