Channel assignment for time-varying demand

This paper presents an integer programming model for dynamic channel assignment (DCA) under space and time-varying traffic demand. The algorithm minimizes the number of channels required to satisfy the traffic demand using a threshold based decision criterion on the carrier-to-interference ratio. A neighborhood based search procedure uses the most recent channel state information to perform a feasible assignment when the demand changes. This technique accelerates the convergence of the algorithm to a local minimum and allows an evaluation of channel gains obtained with increasing neighborhood sizes. This procedure also minimizes the number of channel reassignments in cells whose demand is time-invariant. The performance of a greedy sequential channel assignment heuristic (SA) is examined relative to the spatial distribution of the cells with time-varying demand. Channel gains obtained with DCA relative to the SA scheme range from 30-40% for the examples discussed.