Wireless scheduling with power control

Abstract

We consider the scheduling of arbitrary wireless links in the physical model of interference to minimize the time for satisfying all requests. We study here the combined problem of scheduling and power control, where we seek both an assignment of power settings and a partition of the links so that each set satisfies the signal-to-interference-plus-noise (SINR) constraints.We give an algorithm that attains an approximation ratio of O(log n · log log ), where n is the number of links and is the ratio between the longest and the shortest link length. Under the natural assumption that lengths are represented in binary, this gives the first approximation ratio that is polylogarithmic in the size of the input. The algorithm has the desirable property of using an oblivious power assignment, where the power assigned to a sender depends only on the length of the link. We give evidence that this dependence on is unavoidable, showing that any reasonably behaving oblivious power assignment results in a (log log )-approximation.These results hold also for the (weighted) capacity problem of finding a maximum (weighted) subset of links that can be scheduled in a single time slot. In addition, we obtain improved approximation for a bidirectional variant of the scheduling problem, give partial answers to questions about the utility of graphs for modeling physical interference, and generalize the setting from the standard 2-dimensional Euclidean plane to doubling metrics. Finally, we explore the utility of graph models in capturing wireless interference.

Maximizing Capacity with Power Control under Physical Interference Model in Simplex Mode

“…However, such strong assumption is not only impractical, but also effectively results in the single-hop wireless network in which every pair of nodes can directly with each other, as opposed to the targeted multihop wireless network. Other weaker results on MISL with power control have been obtained in [2] and [5].…”

Leveraging multiple channels in ad hoc networks

“…This is a generalization of the standard requirement of α > 2 in the two-dimensional Euclidean space, as the two-dimensional Euclidean space has a doubling dimension of 2. For more details on fading metric, see [12]. Data Aggregation.…”

Computing large independent sets in a single round

“…, X n } of geometrical objects, the corresponding intersection graph on vertex set X is obtained by introducing an edge between two vertices X i , X j iff the objects X i and X j intersect. In the literature, conflict graphs of wireless networks are often modelled by unit disc graphs [15,33], the intersection graph of discs with equal radii, where the radii of the discs correspond to the transmission range of the wireless transmitters. Unit disc graphs have many beneficial properties that allow for the design of efficient distributed algorithms, but the assumption of identical transmission radii for all wireless transmitters is often too restrictive.…”