Performance Simulation Study On Real-time Media Streaming Over Wireless Networks

The World Wide Web and multimedia streaming are two popular services on the Internet today. Using Web, network users can access rich content, including digital audio and video media. Multimedia streaming has seen increased demand on the Internet in recent years, and has drawn tremendous attention from both academia and industry. Concurrent with these developments,wireless technologies have revolutionalized the way people think about networks, by offering users freedom from the constraints of physical wires. Wireless Internet access is widely available today. Mobile users are interested in roaming and exploiting the technology at their fingertips, as wireless networks bring closer the"anything, anytime, anywhere"promise of mobile networking.A natural step in the wireless Mobile Internet evolution is the convergence of these technologies to support wireless Web and multimedia streaming. Live multimedia streaming offers a remote audience an experience similar to being physically present at the event.Wireless network is a dynamic environment. Communication over wireless links is characterized by limited bandwidth, high error rates, unstable and dynamic changes of wireless channel condition, user mobility, channel competition from multiple clients, and interference from other users on the shared channel, and so on. These characteristics identify significant challenges for providing QoS guarantees for multimedia streaming applications in wireless environments. The obvious concern is that the performance of the traditional Internet protocols may degrade over wireless networks.This thesis uses NS-2 simulation to study MPEG-4 media streaming performance in an IEEE 802.11g Ad Hoc environment.This work begins with thorough investigation and understanding of the performance bottleneck of an IEEE802.11g WLAN supporting real-time media streaming. On this basis, we propose a strategy used to improve the performance of wireless media streaming, so called an"active frame dropping strategy". In detail, the sending side (server), according to the MPEG encoding principle, discards partial MPEG Frames actively when the wireless link condition is getting poor, in order to deliver I- and P-Frames reliably and successfully, and provide high video playing...