I. Introduction
In this paper, we consider a simplified wireless downlink model where a base station serves different users by switching its service amongst the users. We note that such switching might incur a reconfiguration delay (see Figure 1 for an illustration). The reconfiguration delay is defined as the duration between the time at which the base station scheduler decides to serve a user and the time at which the actual service starts. Our motivation to study such systems stem from satellite systems with mechanically steered antenna, electronic beamforming, optical routers [1], and radio transceivers [2] which have reconfiguration delay. Modern mobile communication systems also have reconfiguration delay. We study the problem of scheduling of users for such systems. Wireless communication systems also have random connectivity between the users and the server which varies over time. It is important to control the switching between users and the service rate of transmissions so that random connectivity does not lead to a degradation in performance. Furthermore, service rate control is essential for minimizing the transmission power of a system. Motivated by these objectives, in this paper we consider the design of scheduling policies for wireless systems with reconfiguration delay with the objective of reducing the average delay of data as well as transmission power.
An example wireless downlink with two users and a base station (bs). The data for the users have random bit arrivals into their buffers at the bs. The BS can transmit at some rate to one user from its queue in a slot. The connections between the BS and the users are random and time varying. When the BS switches from serving one user to another there is a reconfiguration delay of slots.