Optimal Time Data Gathering in Wireless Networks with Omni–Directional Antennas

Abstract

Abstract. We study algorithmic and complexity issues originating from the problem of data gathering in wireless networks. We give an algorithm to construct minimum makespan transmission schedules for data gathering when the communication graph G is a tree network, the interference range is any integer m ≥ 2, and no buffering is allowed at intermediate nodes. In the interesting case in which all nodes in the network have to deliver an arbitrary non-zero number of packets, we provide a closed formula for the makespan of the optimal gathering schedule. Additionally, we consider the problem of determining the computational complexity of data gathering in general graphs and show that the problem is NPcomplete. On the positive side, we design a simple (1 + 2/m) factor approximation algorithm for general networks.

Optimal gathering in radio grids with interference

“…Optimal protocols have also been designed for trees with d I = 1 in [8]. When no buffering is allowed, the problem has been solved for trees for d I = 1 [5] and for general d I [4] (where a closed-form expression is given when all vertices have exactly one piece of information to transmit). For square grids with the gateway in the centre, a multiplicative 1.5-approximation algorithm is given in [18] and an additive +1 approximation algorithm is given in [6].…”

Data gathering and personalized broadcasting in radio grids with interference

“…The papers most closely related to our results are [3,4,11,12,15,16]. The data gathering problem is first introduced in [11] under a model for sensor networks similar to the one adopted in this paper.…”

“…In [4] (resp. [3]) optimal gathering algorithms for tree networks in the same model considered in the present paper, are given when d I = 1 (resp., d I ≥ 2). In [3] it is also shown that the Gathering Problem is NP-complete if the process must be performed along the edges of a routing tree for d I ≥ 2 (otherwise the complexity is not determined).…”