Admission Control-Based Multichannel Data Broadcasting for Real-Time Multi-Item Queries

Owing to its potential to satisfy all outstanding queries for the same data item with a single response, on-demand data broadcast becomes a widely accepted approach to dynamic and scalable wireless information dissemination. In some emerging applications, such as road traffic navigation system, users may query multiple data items which have to be received before a deadline. However, in existing works, a client only knows that its query is satisfied when it receives all the required data items or not satisfied when the deadline expires. In this paper, admission control is introduced in data broadcast systems such that clients can be informed in a timely manner. On the one hand, when a query has no hope to be satisfied, it is a waste of time and resources for the client listening to the channels. Instead, an early notification allows the client to take prompt remedial actions to recover the situation. On the other hand, when a query has a very high chance to be served before its deadline, an early guarantee provides a better quality of service to the client. Furthermore, a matching-based allocation scheme is proposed to maximize data sharing among queries and minimize switching among channels in multichannel architectures. Extensive simulations are performed to analyze the validity and efficiency of the proposed admission control and channel allocation schemes on existing scheduling algorithms in a wide range of circumstances.