An approximation algorithm for conflict-aware broadcast scheduling in wireless ad hoc networks

Abstract

Broadcast scheduling is a fundamental problem in wireless ad hoc networks. The objective of a broadcast schedule is to deliver a message from a given source to all other nodes in a minimum amount of time. At the same time, in order for the broadcast to proceed as predicted in the schedule, it must not contain parallel transmissions which can be conflicting based on the collision and interference parameters in the wireless network. Most existing work on this problem use a limited network model which accounts only for conflicts occurring inside the transmission ranges of the nodes. The broadcast schedules produced by these algorithms are likely to experience unpredictable delays when deployed in the network. This is because they do not take into consideration other important sources of conflict in parallel transmissions, namely the interference range and the carrier sensing range. In this paper we develop a conflict-aware network model, which uses these parameters to increase the probability of scheduling conflict-free transmissions, and thereby improve the reliability of the broadcast schedule. We present and prove correctness of a constant approximation algorithm for minimum-latency broadcast scheduling under this network model. We also present a greedy heuristic algorithm for the same problem. Experimental results are provided to evaluate the performance of our algorithms. In addition, the algorithms are analyzed to justify their performance trends.

Interference-Aware Broadcast Scheduling in Wireless Networks

“…Six greedy heuristics are also presented in this paper, and they differ from the one in (14). Unlike those proposed in (5) and (15), where instances need pre-processing, i.e., computing a BFStree or a constant density spanner, respectively, our heuristics do not need any pre-processing of instances.…”

Collision Optimized Broadcast Scheduling in Wireless Sensor Network

“…R. Mahjourian et.al. [3] proposed an approximation algorithm Conflict-Aware Broadcast Scheduler (CABS), which is guaranteed to generate a broadcast schedule whose latency is within a constant ratio of the optimal solution. It uses a layer-by-layer technique to compute the broadcast schedule.…”

A distributed broadcast algorithm for duty-cycled networks with physical interference model

“…However, their distributed algorithm requires a node to exchange a significant number of control messages until all its neighbors receive the broadcast message, leading to an increase in energy consumption. Mahjourian et al [9] study the conflict-aware broadcast problem whereby apart from the transmission and interference range, they also consider the carrier sensing range. They propose a constant approximation algorithm that has a ratio of O(max( , δ) 2 ), where δ is the approximation ratio between the carrier sensing and transmission range.…”

“…Like many other communication protocols, any developed MLBS solution must deal with interference. Unfortunately, the MLBS problem for multi-hop wireless networks has been proven to be NP-hard [5], and researchers have proposed many approximation algorithms; see [4][5][6][7][8][9][10]. These algorithms, however, assume all nodes are always active and adopt highly theoretical disk graph models, in which the transmission and interference range is assumed to be a unit disk centered at each node.…”