Design of broadcast delivery schedules for multiple channels

Datacycle is an information delivery system designed in Bellcore [1]. It uses broadcast delivery and multiple channels of an optical fiber to provide a large volume of information to many users. In this system, the mean access time depends on the broadcast delivery schedule because different information items (called pages) may have different popularity and there are multiple channels for concurrent broadcast delivery. In this paper, we design broadcast delivery schedules for M channels where M ≥ 2 and our objective is to minimize the mean access time. We show that this design problem can be divided into two subproblems: (1) divide the pages into M partitions such that the pages of each partition are broadcast in a distinct channel and (2) determine a broadcast schedule for the pages of each partition. We analyze and solve these subproblems, and we demonstrate that the schedules found can nearly reach a lower bound on the minimal mean access time.