Integrated topology control and routing in wireless optical mesh networks

Abstract

We study the problem of integrated topology control and routing in Free Space Optical (FSO) mesh backbone networks. FSO links are high-bandwidth, low interference links that can be set-up very fast, making them suitable for mesh networking. FSO networks are highly constrained by interface constraints, i.e., constraints on the number of FSO links a node can establish. We prove the problem to be NP-Hard and propose efficient algorithms for integrated topology control and single-path or multi-path routing.

Topology Reconfiguration with Successive Approximations

“…One approach to forming a topology is based on selecting a predetermined order of the source-destination (SD) flows and inserting links one by one. However it is possible to change the order of SD pairs to yield better quality solutions, by a technique called rollout [22]. However large computational complexity is a serious shortcoming of such a technique (We estimate that for ring topologies, it is at least O(N 6 )).…”

“…Rollout heuristics were suggested in [22] to improve the performance of the congestion minimization heuristics described above. A description of the rollout heuristic is excerpted from [19] here.…”

Routing in Degree-Constrained FSO Mesh Networks

“…All the above mentioned routing approaches assume a given physical layer topology. However, for FSO networks, current approaches [8][9][10][11] have combined both topology design and routing problems into one making use of the auto-tracking function of FSO nodes. In these approaches, logical topologies are first calculated at upper layer.…”

Job Mapping and Scheduling on Free-Space Optical Networks

“…The latter can be done with Arimoto's device [18], which acquires the target terminal direction in 0.092-degree field-of-view (FOV) within 10 milliseconds and maintains a stable link within 1.0-degree FOV. In FSO communication systems, each wireless node can be equipped with a limited number of transmitters and receivers, which usually have automatic tracking capabilities to allow for communication endpoint mobility [19]. Two prototypes of existing FSO terminals are presented in [3] and [18].…”