Simulator for adaptive multimedia transmission over wireless networks
University of New Brunswick
Many simulation tools (e.g., NS-2) have been developed to examine the operations and the quality of service (QoS) of different networks, but they cannot demonstrate the visual and auditory impact of network properties on multimedia traffic. This thesis presents a wireless adaptive multimedia simulator (WAMS) that can demonstrate such effects. WAMS uses a compact graphical user interface (GUI) to present the real-time packet delay with the playback of the streaming media over a typical wireless physical channel using IEEE 802.11-based medium access control (MAC). Rate adaptation is also supported to address channel variation. WAMS demonstrates the visual and auditory effects of a variety of factors such as traffic load, fading errors, and rate adaptation. We also carried out tests on user-perceived quality of experience (QoE) with 54 test cases comprising 3 videos, 2 audio clips, and 1 combined video and audio clip produced by WAMS. Ten people (assessors) viewed and listened to these clips and compared them to the original multimedia according to a five-point impairment measure. We find that the subjective QoE is quite sensitive to audio/video content although consistent with objective QoS metrics. Statistical difference of means tests show that the video with slower motion and fewer colours is likely to offer a better delay tolerance, and the audio is less sensitive to the bit error probability (BEP) than the video.