A Fast Distributed Approximation Algorithm for Minimum Spanning Trees in the SINR Model

A fundamental problem in wireless networks is the minimum spanning tree (MST) problem: given a set V of wireless nodes, compute a spanning tree T , so that the total cost of T is minimized. In recent years, there has been a lot of interest in the physical interference model based on SINR constraints. Distributed algorithms are especially challenging in the SINR model, because of the non-locality of the model. In this paper, we develop a fast distributed approximation algorithm for MST construction in an SINR based distributed computing model. For an n-node network, our algorithm’s running time is O(D log n + μ log n) and produces a spanning tree whose cost is within O(log n) times the optimal (MST cost), where D denotes the diameter of the disk graph obtained by using the maximum possible transmission range, and μ = log dmax dmin denotes the “distance diversity” w.r.t. the largest and smallest distances between two nodes. (When dmax dmin is n-polynomial, μ = O(log n).) Our algorithm’s running time is essentially optimal (upto a logarithmic factor), since computing any spanning tree takes Ω(D) time; thus our algorithm produces a low cost spanning tree in time only a logarithmic factor more than the time to compute a spanning tree. The distributed scheduling complexity of the spanning tree resulted from our algorithm is O(μ log n). Our algorithmic design techniques can be useful in designing efficient distributed algorithms for related “global” problems in wireless networks in the SINR model.