A Traffic-Aware Channel and Rate Reassignment Algorithm for Wireless Mesh Networks

Abstract

Channel assignment is among the most challenging issues for multiradio wireless mesh networks, given the variety of objectives that can be pursued and the computational complexity of the resulting problems. The channel assignment problem has been also shown to be interdependent with the routing problem, i.e., the problem to determine the amount of traffic flow to be routed on every link. Such a relationship raises the need to recompute the channel assignment every time the traffic pattern changes. However, channel assignment algorithms designed to assign channels from scratch will likely return a completely different configuration of radios, which would disrupt the network operation for the time required to switch to using the links established on the new channels. As shown by the experiments that we conducted, such a time may not be negligible, due to the resistance of routing protocols designed for wireless ad hoc and mesh networks to rapidly flagging a link as established/lost. Such a consideration, along with the observation that channel assignment algorithms may be suboptimal, led us to the design of a channel reassignment algorithm that takes the current channel assignment into account and attempts to cope with the new traffic pattern in the best manner possible while modifying the channel on a limited number of radios. In this paper, we illustrate such a channel reassignment algorithm and evaluate its performance by means of both simulations and experiments with real hardware

A comparative study of channel switching latency for conventional and SDN-based routing in multi-hop multi-radio Wireless Mesh Networks

“…In one of the recent experimental studies of the channel switching delay on OLSR, it is shown that the disruption in network connectivity results from the channel switching is not insignificant [1]. Moreover, the resultant packet loss due to the channel switching can lead to the decrease in the congestion window and increase in the retransmission timer for TCP flows and thus reducing the throughput for a long period [13]. In this work, we intend to use SDN as a promising paradigm to alleviate the existing concerns on channel switching latency.…”

Fair rate control for cognitive multi-channel wireless ad hoc networks

“…Franklin et al [13] proposed reconfiguration algorithms for channel assignment and flow rate allocation in response to dynamic traffic demands, unlike most previous works dealing with the static traffic demand. Avallone http://jwcn.eurasipjournals.com/content/2014/1/11 et al [14] considered a new set of flow traffic in adapting channel and rate assignment by minimizing the maximum total utilization, which resulted in the enhancement of throughput. Similar to this trend of adaptive channel assignment, we propose a long-term channel reselection method for the fixed receiving interface with careful consideration not only of in-network node population but also of interference from out-of-network primary nodes.…”

Joint channel and flow assignment algorithm for wireless mesh networks

“…However, in order to fully improve the throughput of the WMN by utilizing multiple orthogonal channels, the channels have to be assigned appropriately to each link. There are several studies on how to assign channels to each link in order to improve throughput of WMNs with multiple channels and multiple antennas [1]- [4]. In [1], a channel and rate reassignment algorithm with considering a change in the traffic flows is proposed.…”

“…There are several studies on how to assign channels to each link in order to improve throughput of WMNs with multiple channels and multiple antennas [1]- [4]. In [1], a channel and rate reassignment algorithm with considering a change in the traffic flows is proposed. In [2], the authors propose a channel allocation algorithm and a routing algorithm with utilizing both static and dynamic interfaces.…”