The Design And Development Of Full-Duplex Audio And Communication Based On Smart Phone

With the development of embedded technology, mobile phone is becoming intelligent, advanced and has stronger CPU handling ability, more memory and more extensible ability.The smart phone manufacturer provides the wireless access (WLAN) hardware modules and software modules in smart phone and the public WLAN APIs in mobile phone, including APIs and hardware interface.With the ability to access the IP network using WLAN, the smart phone provides the user the ability to browse the Internet, wireless personal data administrator, and send or receive the e-mail and multimedia services.This thesis is a part of VOIP project, and includes three parts:First, Full-duplex audio based on the Nokia E61 platform, design and develop the full-duplex audio communication based on the client/server architecture of the Symbian OS. APS (Audio Proxy Server) is used as a server component that provides access to S60 audio subsystem and the 3^rd development APIs. We developed a client to access the APS server and receive or send the audio data to queue handler.Second, analyze the IEEE 802.11 protocol, because the Nokia E61 supports the IEEE802.11 b/g WLAN standard. We develop the WLAN access point, state settings, network mode, security mode, security settings using WLAN APIs.Third, we realize the reliable communication by RTP and Socket communication. The RTP is built on top of the User Datagram Protocol (UDP). Audio data is encrypted by RTP Header and then transferred to the IP network using UDP when the WLAN access to IP network.