A Cross-layer Approach to Optimal Wireless Link Scheduling with SINR Constraints

In this paper, we address the problem of determining the minimum-length schedule that satisfies certain link demands in a wireless network. Traditional approaches for the determination of minimum-length schedules are based on a collision channel, in which neighboring transmissions cause destructive interference if and only if they are within the "interference region" of the receiving nodes. In contrast, we use a cross-layer approach that incorporates the realistic properties of the physical layer by requiring that a threshold on signal-to-interference-and-noise ratio (SINR) be exceeded for a transmission to be considered successful. The minimum-length scheduling problem can be formulated as a simple linear programming problem. However, such a direct approach requires the enumeration of all feasible matchings, which may not be computationally efficient for larger sized networks. Therefore, we present an an alternative solution procedure based on problem decomposition, that selectively enumerates only those matchings that contribute towards the optimal.