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—Over years, virtual backbone has attracted lots of attentions as a promising approach to deal with the broadcasting storm problem in wireless networks. One popular way to construct a quality virtual backbone is to solve the minimum connected dominating set problem. However, a virtual backbone computed in this way is not resilient against topology change(More)
—Neighbor discovery (ND) is a basic and crucial step for initializing wireless ad hoc networks. A fast, precise, and energy-efficient ND protocol has significant importance to subsequent operations in wireless networks. However, many existing protocols have a high probability of generating idle slots in their neighbor discovering processes, which prolongs(More)
—A Virtual Backbone (VB) of a wireless network is a subset of nodes such that only VB nodes are responsible for routing-related tasks. Since a smaller VB causes less overhead, size is the primary quality factor of VB. Frequently, Unit Disk Graphs (UDGs) are used to model 2D homogeneous wireless networks, and the problem of finding minimum VBs in the(More)
—In this paper, we study the problem of constructing quality fault-tolerant Connected Dominating Sets (CDSs) in homogeneous wireless networks, which can be defined as minimum k-Connected m-Dominating Set ((k, m)-CDS) problem in Unit Disk Graphs (UDGs). We found that every existing approximation algorithm for this problem is incomplete for k ≥ 3 in a sense(More)
Previously, we proposed Minimum Average Routing Path Clustering Problem (MARP-CP) in multi-hop USNs. The goal of this problem is to find a clustering of a USN so that the average clustering-based routing path from a node to it nearest underwater sink is minimized. We relaxed MARPCP to a special case of Minimum Weight Dominating Set Problem (MWDSP), namely(More)
The multiple UnderWater Sink (UW-Sink) architecture is introduced to resolve the scal-ability problem in USNs. To maximize the benefit of this architecture, the UW-Sinks should be located carefully. Previously, we proposed Minimum d-Hop UW-Sink Placement Problem (MdHUWSPP) for time-sensitive applications, whose objective is minimizing the number of UW-Sinks(More)
In this paper, we study the problem of computing quality fault-tolerant virtual backbone in homogeneous wireless network, which is defined as the <i>k</i>-connected <i>m</i>-dominating set problem in a unit disk graph. This problem is NP-hard, and thus many efforts have been made to find a constant factor approximation algorithm for it, but never succeeded(More)
—This paper considers the problem of computing the optimal trajectories of multiple mobile elements (e.g. robots, vehicles, etc.) to minimize data collection latency in wireless sensor networks (WSNs). By relying on slightly different assumption , we define two interesting problems, the k-traveling salesperson problem with neighborhood (k-TSPN) and the(More)
In this paper, we propose a new multiple-sink positioning problem in wireless sensor networks to best support real-time applications. We formally define this problem as the <i>k</i>-Sink Placement Problem (<i>k</i>-SPP) and prove that it is APX-complete. We show that an existing approximation algorithm for the well-known -center problem is a constant factor(More)