🤖 AI Summary
This study addresses the relocation problem of wireless nodes on a closed ring, aiming to preserve bidirectional connectivity between every pair of adjacent nodes and achieve barrier coverage while minimizing the maximum movement distance across all nodes. The work presents the first linear-time optimal algorithm for this problem and further extends it to obtain a lexicographically optimal solution—enhancing fairness in node movements without compromising global optimality or increasing time complexity. Leveraging geometric properties of the ring topology and a greedy strategy, the proposed algorithm efficiently computes an optimal deployment that guarantees coverage quality while significantly improving deployment efficiency.
📝 Abstract
The problem of maintaining connectivity of a wireless network on a closed cycle is studied in this paper. In the initial input, we have $n$ points located on a closed cycle. The points can move along the cycle, and if the distance between two points is at most a given value $r$, we say these two points are connected. The goal of the problem is to move the points along the cycle such that any adjacent pair of points is directly connected--i.e., there exist two paths between them in opposite directions along the cycle--while minimizing the maximum movement over all points. This problem is motivated by applications in mobile wireless networks, including sensors, vehicles, and satellites operating on closed orbits. It is also applicable to barrier or border coverage problems, where sensors are deployed along a closed boundary and coverage is achieved through repositioning along the cycle. We present a linear time optimal algorithm for this problem. Then we refine the algorithm to obtain a lexicographically optimal solution without increasing the time complexity.