Improved On-Line Broadcast Scheduling with Deadlines

We study an on-line broadcast scheduling problem in which requests have deadlines, and the objective is to maximize the weighted throughput, i.e., the weighted total length of the satisfied requests. For the case where all requested pages have the same length, we present an online deterministic algorithm named BAR and prove that it is 4.56competitive. This improves the previous algorithm of Kim and Chwa [11] which is shown to be 5-competitive by Chan et al. [4]. In the case that pages may have different lengths, we prove a lower bound of (/ log ) on the competitive ratio where is the ratio of maximum to minimum page lengths. This improves upon the previous lower bound in [11, 4] and is much closer to the current upper bound of ( + 2 + 2) in [7]. Furthermore, for small values of we give better lower bounds.

• Type: Conference
• Year: 2006
• Where: COCOON
• Authors: Feifeng Zheng, Stanley P. Y. Fung, Wun-Tat Chan, Francis Y. L. Chin, Chung Keung Poon, Prudence W. H. Wong
• Keywords: Algorithm Named Bar, COCOON 2006, Combinatorics, Lower Bounds, Weighted Total Length