Approximation Algorithm for Minimum Weight $(k,m)$-CDS Problem in Unit Disk Graph

TL;DR

This paper introduces the first constant approximation algorithm for the weighted $(k,m)$-connected dominating set problem in unit disk graphs, enhancing fault-tolerant virtual backbone design in wireless sensor networks.

Contribution

It presents a novel constant approximation algorithm for the weighted $(k,m)$-CDS problem with general fixed $k,m$, extending prior work limited to unweighted or specific cases.

Findings

Achieves a performance ratio of $( ext{alpha}+2.5k ho)$ for $k extgreater=3$

Achieves a performance ratio of $( ext{alpha}+2.5 ho)$ for $k=2$

First constant approximation for weighted $(k,m)$-CDS in unit disk graphs.

Abstract

In a wireless sensor network, the virtual backbone plays an important role. Due to accidental damage or energy depletion, it is desirable that the virtual backbone is fault-tolerant. A fault-tolerant virtual backbone can be modeled as a $k$-connected $m$-fold dominating set ($(k,m)$-CDS for short). In this paper, we present a constant approximation algorithm for the minimum weight $(k,m)$-CDS problem in unit disk graphs under the assumption that $k$ and $m$ are two fixed constants with $m\geq k$. Prior to this work, constant approximation algorithms are known for $k=1$ with weight and $2\leq k\leq 3$ without weight. Our result is the first constant approximation algorithm for the $(k,m)$-CDS problem with general $k,m$ and with weight. The performance ratio is $(\alpha+2.5k\rho)$ for $k\geq 3$ and $(\alpha+2.5\rho)$ for $k=2$, where $\alpha$ is the performance ratio for the minimum weight $m$-fold dominating set problem and $\rho$ is the performance ratio for the subset $k$-connected subgraph problem (both problems are known to have constant performance ratios.)