A distributed load-based transmission scheduling protocol for wireless ad hoc networks

Abstract

This paper presents a load-based transmission scheduling (LoBaTS) protocol for wireless ad hoc networks. Since terminals in these networks may be required to forward unequal amounts of traffic, a transmission scheduling protocol which assigns equal transmission capacity to all terminals may result in traffic bottlenecks as traffic load increases. The LoBaTS protocol allows terminals to alter their existing transmission schedules so that those terminals which are required to forward more traffic can reserve additional transmission slots, thereby alleviating traffic bottlenecks. The LoBaTS protocol is designed to avoid creation of new traffic bottlenecks, maintain collision-free broadcast transmissions, and execute with minimal disruption to the network. In addition, it requires only local information to operate, making it suitable for implementation in a distributedcontrol environment. Simulations utilizing a variety of test networks and traffic conditions show that the LoBaTS protocol greatly improves end-to-end packet delay, throughput, and completion rate when compared to a transmission schedule which does not account for traffic load.

A Load-Based Approach for Selecting the Backbone Terminals for a Hierarchical Ad Hoc Network

“…Minimizing the maximum load-factor value of the network reduces the traffic load at the bottleneck terminal. The LoBaTS protocol [18] alleviates traffic congestion by altering the existing transmission schedule and providing additional transmission slots to terminals with large load-factor values, thereby increasing their effective transmission rate and minimizing their corresponding loadfactor values. However in this research work, we address this problem by reducing the number of terminals that participate in forwarding packets and finding suitable relay terminals to add to the backbone network to reduce the load-factor value of the bottleneck terminal.…”

Immediate neighbor scheduling (INS): An adaptive protocol for mobile ad hoc networks using direct-sequence spread-spectrum modulation

“…Often, these constraints take the form of link activation to support unicast transmissions or node activation to support broadcast transmissions [2]. Additional objectives may include designing schedules which minimize end-to-end delay [3,4], balance traffic loads [5][6][7], or minimize the length of the repeating transmission frame to enable more frequent transmissions [8]. There are many centralized algorithms for computing time-slot assignments based on some criteria, such as [9][10][11][12]; however, the focus here is on mobile ad hoc networks with no centralized control, leading us to consider only distributed protocols which do not require global information.…”

Joint per-flow scheduling and routing in wireless multihop networks

“…Wolf et al [3] proposed a distributed load-balanced node TDMA scheduling algorithm for wireless ad-hoc networks, which allows nodes to alter their existing transmission schedules so that those nodes which are required to forward more traffic can reserve additional transmission slots, and thereby alleviating traffic bottlenecks. This is achieved by assigning additional slots to congested nodes.…”