Assigning and Scheduling Partially Overlapping Channels in Wireless Mesh Networks

The design and the management of Wireless Mesh Networks (WMNs) are currently associated with the most active research area within the current wireless networking paradigms. WMNs inherit features from existing wireless networking technologies such as WLANs, mobile ad hoc networks. Because WMNs are easy to deploy and with low power consumption, there is a phenomenal growing interest in seeing WMNs as the next wireless backhaul networks, and an alternative to the existing wired infrastructure. The earliest development of WMNs had begun with single-channel single-radio mesh networks. This technology then evolved towards multi-channel single-radio mesh networks, and then to multi-channel multi-radio mesh networks. WMNs operate in North America on IEEE 802.11 2.4 GHz spectrum, which provides up to 11 channels. Despite the availability of 11 channels, only 3 (1, 6, 11) orthogonal channels can be used concurrently. The efficiency of multi-channel multi-radio wireless mesh networks can be improved with the increase of the number of channels used concurrently and of multiple radios. In this study, we investigate how to design a scalable channel assignment and a scheduling algorithm, which both exploit partially overlapping channels in order to increase the throughput in comparison with the one that can be obtained only using three orthogonal channels. In order to accurately take into account the radio interferences, we use the physical interference model to estimate the interferences among wireless links. We then introduce the definition of transmission configurations, which are sets of links, which can transmit concurrently. These links can be assigned with channels of overlapping or orthogonal in nature. We then design a TDMA based scheduling allowing a transmission configuration to transmit concurrently in a time slot. Finally, we evaluate all our algorithms through extensive simulations. Our numerical experiments show that we can gain up to 25% for the throughput by appropriately managing all the available channels

Radio Co-location Aware Channel Assignments for Interference Mitigation in Wireless Mesh Networks

Designing high performance channel assignment schemes to harness the potential of multi-radio multi-channel deployments in wireless mesh networks (WMNs) is an active research domain. A pragmatic channel assignment approach strives to maximize network capacity by restraining the endemic interference and mitigating its adverse impact on network performance. Interference prevalent in WMNs is multi-faceted, radio co-location interference (RCI) being a crucial aspect that is seldom addressed in research endeavors. In this effort, we propose a set of intelligent channel assignment algorithms, which focus primarily on alleviating the RCI. These graph theoretic schemes are structurally inspired by the spatio-statistical characteristics of interference. We present the theoretical design foundations for each of the proposed algorithms, and demonstrate their potential to significantly enhance network capacity in comparison to some well-known existing schemes. We also demonstrate the adverse impact of radio co- location interference on the network, and the efficacy of the proposed schemes in successfully mitigating it. The experimental results to validate the proposed theoretical notions were obtained by running an exhaustive set of ns-3 simulations in IEEE 802.11g/n environments.Comment: Accepted @ ICACCI-201

Efficient Use of Partially Overlapping Channels in WMNs

There has been growing interest in using Wireless Mesh Networks (WMNs) because of their advantages such as easier to scale up and self-organization. We instigate whether increasing the number of available channels through the use of Partially Overlapping Channels (POCs) is always useful for improving the Quality of Service (QoS) of WMNs namely the throughput or delay. For the purpose of this thesis, we design a set of algorithms for: i) Channel assignment; ii) Transmission Configurations (TCs) which is a set of links with the ability of sending data simultaneously; iii) power control; and iv) delivery of packets to their destination in order to take advantage of POCs in WMNs. We evaluate our proposed algorithms by a comprehensive set of numerical experiments. Numerical experiments indicate that using POCs leads not only to increase throughput of networks, but also it can decrease delay of packet delivery

Multi-Channel Multi-Radio Using 802.11 Based Media Access for Sink Nodes in Wireless Sensor Networks

The next generation surveillance and multimedia systems will become increasingly deployed as wireless sensor networks in order to monitor parks, public places and for business usage. The convergence of data and telecommunication over IP-based networks has paved the way for wireless networks. Functions are becoming more intertwined by the compelling force of innovation and technology. For example, many closed-circuit TV premises surveillance systems now rely on transmitting their images and data over IP networks instead of standalone video circuits. These systems will increase their reliability in the future on wireless networks and on IEEE 802.11 networks. However, due to limited non-overlapping channels, delay, and congestion there will be problems at sink nodes. In this paper we provide necessary conditions to verify the feasibility of round robin technique in these networks at the sink nodes by using a technique to regulate multi-radio multichannel assignment. We demonstrate through simulations that dynamic channel assignment scheme using multi-radio, and multichannel configuration at a single sink node can perform close to optimal on the average while multiple sink node assignment also performs well. The methods proposed in this paper can be a valuable tool for network designers in planning network deployment and for optimizing different performance objectives