Smooth Handoff for Stream Media

The current mobile wireless networks often fail to provide smooth handoffs due to the following two reasons: 1) packets may get lost due to the re-routing caused by handoffs; 2) due to the disparity in available bandwidth among wireless cells, handoffs may cause congestion. To avoid stream disruption and drastic quality degradation of stream transmission during handoffs, we developed a multi-path handoff scheme to solve that problem. In the proposed scheme, multiple paths are set up during the handoff. Transmission rate on each path is controlled separately to avoid congestion. By transmitting important data (base layer) in video stream redundantly through multiple paths, we avoid stream disruption during the handoff; by exploiting extra bandwidth on high bandwidth path to send additional data (enhancement layer), we improve the video quality. Simulation is conducted to evaluate the performance of the proposed scheme. 

Presentations

• MURI 2002 Poster
• ACM 1st International Workshop on Wireless Mobile Applications and Services on WLAN Hotpots 2003 (WMASH'03)
• IEEE Computer Communication Workshop 2003 (CCW'03)
• Presentation in ICS 243A (Lecture Notes) 

Publications

• Y. Pan, M. Lee, J.B. Kim, T. Suda, “An End-to-End Multi-Path Smooth Handoff Scheme for Stream Media”, in the IEEE Journal of Selected Areas of Communications (JSAC), Special-Issue on All-IP Wireless Networks, Vol. 22, No. 4, pp. 653-663, May 2004
• Y. Pan, M. Lee, J.B. Kim, T. Suda, “An End-to-End Multi-Path Smooth Handoff Scheme for Stream Media”(short version), in the Proceedings of ACM WMASH’03 Workshop, page 64-74, Sept. 2003, San Diego, CA
• Y. Pan, M. Lee, J. B. Kim, T. Suda, “Smooth Handoff Scheme for Stream Media with Bandwidth Disparity in Wireless Cells”, in the Proceedings of IEEE CCW’03 Workshop, page 9-16, Oct. 2003, Data Point, CA

Source Code and Demo Traces

OPNET simulation code

MPEG-2 and Wavelet Video Codec

Demo Video traces:

• Original Video Trace
• Received Video Trace with the proposed scheme
• Comparison to other single path handoff schemes

Researchers:

Yi Pan ( ypan@ics.uci.edu )