A Buffer-Controlled Adaptive Video Streaming for Mobile Devices

In a recent VoD application, a stationary VoD server delivers video stream to a mobile device, particularly PDA, over wireless. Our objective is to develop a simple cost effective scheme which offers an acceptable video quality over a noisy wireless channel using a buffer size available at PDA. The key idea is that the sending rate at the server is faster than the playback rate at the handheld device. Thus, we classify the buffer at the mobile device into three distinct states depending on its level (occupancy). For each of these states a different rate control scheme has been formulated and applied. In addition, typical adjustable parameters used to estimate the lower and the upper bound on the buffer size were determined by using the results of a series of simulations. Since the sending rate increases as the inter-packet delay (IPD) at the sender decreases, we vary IPD to control the rate with the buffer state. Measures were carried out on a test- bed which reproduces a real prototype of the wired- cum-wireless topology.