On-demand broadcast algorithms with caching on improving response time for real time information dispatch systems

This paper presents a performance study on various broadcast algorithms and caching strategies for on-time delivery of data in a real time information dispatch system. The objective of the study is not just aiming at on time delivery, but to improve the response time on the data requests. We propose and perform a series of simulation experiments, using real traffic data from the access log of the official web site for FIFA 2002 World Cup. Simulation results show that our proposed broadcast algorithm not only succeeds in providing good on-time delivery of data but at the same time provides 2 to 3 times of improvement in response time over traditional scheduling algorithms like first-in-first-out (FIFO) and earliest-deadline-first (EDF). The simulation results also show that our proposed caching strategy provides further improvement in percentage of requests finished in time over traditional caching strategy like least recently used (LRU).