Throughput improvement by disruption-suppressed channel switching in multi-channel ad-hoc networks

As Internet of Things (IoT) and smart devices are becoming widespread, expectations for large-scale ad-hoc networks are increasing. To accommodate a large number of nodes, ad-hoc networks should use multiple channels. Thus, dynamic channel switching methods in multi-channel ad-hoc networks have been investigated to control congestion of the channel. However, such channel switching has a considerable impact on the routing layer. Channel switching causes link failure, and routing protocols are forced to recalculate the route related to channel switching nodes. As a result, end-to-end communications may be disrupted during route recalculations. In this paper, we propose a channel-switching scheme which mitigates channel congestion for throughput improvement while suppressing the end-to-end communication disruption. The proposed scheme properly classifies nodes according to whether they are allowed to switch channels on the basis of the current route by which nodes with multiple radio interfaces are connected. Selecting nodes to switch their channel for mitigating congestion can suppress the communication disruption. Our simulation results showed that our proposed scheme achieved 1.8 times throughput by mitigating congestion compared with the initial state at which nodes randomly select the channel. It was also similar throughput to a centralized scheme which dedicate to mitigate congestion. Besides, proposed scheme produced half the number of communication disruptions owing to the proper selection of nodes.