Throughput Optimisation in Multi-Channel Wireless Mesh Networks

Wireless Mesh Networks (WMNs) are becoming common due to the features provided, especially the low cost and self-configuration ability. In WMNs, the data traffic is transmitted through intermediate nodes. With the nature of wireless networks, forwarding (routing) the data from the senders to the destinations and managing the network resources efficiently are challenging. There are various reasons that affect the network performance especially the throughput reduction such as signal interference, mobility and congestion. The focus of this research is to improve the throughput in the multi-channel wireless mesh networks from two perspectives. The first issue considered in this work is selecting a path with the maximum available bandwidth and low signal interference to transmit data from the source to the destination. Thus, we design two routing metrics, the Expected Transmission Time with Queueing (ETTQ) and the Delay and Interference Aware Metric (DIAM), that consider the intra-flow interference, inter-flow interference and delay. The simulation results of these routing metrics by the Network Simulator (NS2) demonstrate that the DIAM metric can estimate the intra-flow interference, inter-flow interference and delay of a link and then select the path efficiently. The second problem that has been addressed to improve the network throughput is controlling the network congestion. In this work, we address the issue of packet drops in the Interface Queue (IFQ) due to the node congestion. We solve this issue by reducing the number of dropped packets at IFQ by allocating the flow rate from the solution of a linear program (LP). The simulations using NS2 have shown that the LP-based flow rate improves the network throughput in chain networks. In addition, with the complex networks, traffic rate adjustments alone are not sufficient and we propose a simple forwarding delay scheme for the Ad Hoc On-Demand Distance Vector protocol with Forwarding delay (AODV-F) with DIAM routing metric that reduces node congestion and improves throughput. The forwarding delay scheme has also been evaluated using NS2. Moreover, the LP adjusted flow rate and the forwarding delay address the issue of maximising the flow fairness as the results have demonstrated

Delay and interference aware metric in multi-channel wireless mesh network

With the features provided by wireless mesh networks (WMN) and the increasing number of users, the Quality of Service (QoS) has become essential to support multimedia applications. In addition, employing the multichannel approach has led to the improvement of the network performance. However, selecting a path with the maximum available bandwidth to transmit data from the source to the destination is a critical issue because of intraflow interference and inter-flow interference. In this paper, we propose a routing metric Delay and Interference Aware Metric (DIAM), which selects a path with high data rate and low signal interference to achieve high performance. The DIAM metric estimates the intra-flow interference, inter-flow interference and delay of a link for multi-channel WMNs. We have implemented DIAM in the AODV routing protocol using the Network Simulator (NS2). The performance of our metric is measured by conducting simulation experiments in static and mobile networks

Effective Beamforming Technique Amid Optimal Value for Wireless Communication

In the notion of communication system resource provision specifically, beam-forming is a concept of proficient utilization of the power of transmission. Network densification and massive MIMO allows us to control the power efficiency and can be effectively distributed among different users by reducing cost. We presented a practical scenario for the performance of massive MIMO and multi-small cell system to analyze the overall performance of the system. Our work is based on the resource allocation with optimal structural constraints to maintain the cost effectiveness while considering economic implications. The base stations located far away from the users receive attenuated signals and give rise to path loss, whereas the problems of inter cell interference also arise due to transmission from a base station to others cells. The performance of the cellular system can be enhanced with the combination of massive Mimo and small cells, where we simulate and also provide an analysis on practical system with optimal and low complexity beam-forming. The proposed scenario illustrates a structure with an optimal linear transmit beamforming regarding an efficient number of parameters to not lose optimality, which is extendable to designate any specific cellular network in consideration. Our approach exploited schemes with low complexity that are facilitating in complete solution formation, and tested them in various and all possible cases and scenarios