Scheduling and Access Control for Wireless Connections with Throughput Guarantees

Emerging wideband code division multiple access (WCDMA) data services will likely require resource allocation to ensure that throughput targets are met. Scheduling and access control can both be key components in this task. In this chapter, we introduce a two-layer scheduler and connection access controller that attempts to balance efficiency with fairness. We first propose a scheduler that takes advantage of variations in the wireless channel—both channel fluctuations in time for each user, and channel variations among multiple users at a particular time. By mixing a max-min policy with a policy of serving users with relatively good channels, the scheduler can achieve individual average throughput targets in a manner that encourages system efficiency. We then propose a two-layer algorithm that offers targeted throughput for interactive nomadic data streams, such as video or music streaming. The design purpose is to provide users with service differentiation, which lays the groundwork for network optimization in terms of capacity or utility, and can be easily extended to revenue maximization. Upon the request of a data stream connection, a target throughput is negotiated between the user and the network/base station. The network attempts to achieve the throughput targets over the duration of each individual connection by maximizing a system objective based on users’ satisfaction that is represented by a utility function. We assume that a users’ utility function depends not only on the throughput target but also on final achieved throughput. The algorithm integrates connection access control and resource allocation per connection request with rate scheduling on a per frame basis adaptive to slow fading. Through numerical analysis, the proposed joint scheduler and connection access controller is shown to achieve the design goals.