Interference-aware Channel Assignment Research Articles

Q-Learning and MADMM Optimization Algorithm Based Interference Aware Channel Assignment Strategy for Load Balancing in WMNS

Wireless Mesh Networks (WMNs) have been considered one of the main technologies for configuring wireless machines since they appeared. In a WMN, wireless routers provide multi-hop wireless connectivity between hosts on the network and allow access to the internet through the gateway routers. These wireless routers are normally equipped with the multiple radios in the wireless mesh network that operate on multiple channels with the multiple interference, which is caused to reduce the network performance and end-to-end delay. In this paper, we proposed an efficient optimization algorithm to solve the channel assignment problem which cause due to the multichannel multiradios in WMN’s. The main objective of our paper is to minimize the channel interference among networked devices. So, initially we construct a multicast tree with minimum interference by using Q-Learning algorithm, which is helps to minimize the end-to-end delay of packet delivery. From the constructed multicast tree, we intend to develop a channel assignment strategy with the minimum interference by using Modified version of Alternative Direction Method of Multipliers (MADMM) optimization algorithm, which is helps to increase the network throughput and packet delivery ratio. The proposed strategy was implemented by using NS-2 (Network Simulator-2) and the experimental result show that the performance of the proposed method is very high compared to the other method and the performance was calculated by using the feature metrics such as average throughput, packet delivery ratio, end-toend delay and total cost, which is compared with the other existing channel assignment strategies such as Learning Automata and Genetic Algorithm (LA-GA), GA-based approach, link-channel selection and rate-allocation (LCR) and learning automata based multicast routing (LAMR) channel assignment methods.

Interference-aware channel assignment and power allocation for device-to-device communication underlaying cellular network

Device-to-device (D2D) communication is a promising technology in 5G new radio (NR) interface to improve the system performance in terms of high data rate, low latency, coverage extension, traffic offloading, and higher spectrum and energy efficiency. In this study, channel assignment and power allocation techniques for D2D communication underlaying cellular network are proposed, those in turn, lead to a spectrum-efficient system. Firstly, the channel assignment problem is solved by employing channel-characteristics of target link and interference links. Then the power allocation problem is solved by allocating the optimal power to the D2D transmitters with allowable interference. This optimal power allocation approach allows multiple D2D communications to reuse the available cellular uplink resources. Numerical results demonstrate significant throughput gains for D2D communication for different transmission and interference power settings. Network throughput comparison with other existing approaches is provided to confirm the efficacy of the proposed approach. In addition, energy efficiency analysis is carried out by considering D2D transmission power, circuit power consumption, D2D link distance, and D2D user density.

A dynamic channel assignment method for multichannel multiradio wireless mesh networks

The popularity of wireless communication accelerates research on new technologies that are required to satisfy users' needs. Wireless mesh networks (WMNs), which are additional access technologies instead of being a renewed one, have an important place among next-generation wireless networks. In particular, the capability of working without any infrastructure is the most outstanding advantage of WMNs. There are many studies aimed at WMNs, particularly channel assignment and routing methods for multichannel multiradio structures that provide higher data capacity. Interference, which has a direct effect on the quality of communication, is still a challenge to be addressed. In this study, multichannel multiradio WMNs and various channel assignment schemes are analyzed. Directional mesh (DMesh) architecture, which uses directional antennas to form a multichannel structure, is analyzed in terms of channel assignment procedure. A new interference-aware channel assignment scheme that aims to eliminate DMesh's disadvantages is proposed and performances of both schemes are compared. Several results of experimental analysis prove that the proposed channel assignment scheme improves the performance of DMesh

CCRA: channel criticality based resource allocation in cognitive radio networks

SummaryIn cognitive radio networks, signal to interference plus noise ratio (SINR) is a quantity that is used to analyze the bounds of the capacity of a channel. This is the reason for SINR being one of the important parameters toward evaluating the performance of spectrum sharing in every network. To maximize the channel utilization in any network, the SINR of a channel should be considered to be within a threshold. This also leads to lesser power consumption, and the quality of service for the licensed users is maintained. Further, reduced SINR leads to an improvement in the quality of communication in the network. In this paper, a graph theoretic measure for the efficient utilization of channels in cognitive radio networks has been proposed and is named as channel criticality based resource allocation (CCRA). Using the SINR as the weight of the graph, a novel concept of channel criticality has also been introduced in this work. The proposed CCRA technique has also been compared with the existing interference aware channel assignment (IACA) technique in terms of the channel utilization. Through simulations, the CCRA has been observed to outperform the IACA scheme. The average channel utilization of the proposed CCRA was observed to have increased by 8%, when the secondary users were introduced in the network as compared with the IACA technique. Copyright © 2015 John Wiley & Sons, Ltd.

Simulation of multi-radio multi-channel 802.11-based mesh networks in ns-3

In the context of wireless network simulation, many simulators are capable of evaluating the performance of single-channel network protocols, but they need many modifications to be able to simulate multi-radio multi-channel networks. We address the problem of simulating channel assignment protocols for multi-radio wireless mesh networks in ns-3 simulator, providing the essential steps needed to simulate a channel assignment protocol. In addition, we explain the details of simulating the Semi-dynamic Interference aware Channel Assignment (SICA) protocol as an example. We use SICA as a reference to address the challenges of validating and verifying the simulation model. To validate the channel assignment model in SICA, we use mathematical validation based on Markov chains. Furthermore, we propose a novel automated test module to verify the simulation process.

Interference-aware QoS routing and dynamic channel assignment for multi-radio multi-channel wireless mesh network

QoS routing in multi-channel wireless mesh networks protocols is a very challenging problem. In this paper, we propose an on-demand bandwidth-constrained routing protocol combined with dynamic channel assignment for multi-radio multi-channel wireless mesh networks with the IEEE 802.11 DCF MAC protocol. A multi-channel available bandwidth estimation method is proposed which is based on the exchange of the bandwidth information for neighbour nodes at first, then a new jointing channel assignment and routing algorithm is designed which dynamically assigns the channel through the available bandwidth in the routing process according to the requirement of bandwidth, distributed call admission control is integrated to prevent network overload and the optimal path metric is advised to establish interference-aware QoS routing. Simulation results show that the routing algorithm can reduce co-channel interference and improve network performance and acceptance rate through assigning channels dynamically.

An Efficient and Fair Strategy for Radio Resources Allocation in Multi-radio Wireless Mesh Networks

A Load and Interference aware Resource Allocation strategy (LIRA) is proposed for multi-radio Wireless Mesh Networks (WMNs), combining multiple mechanisms that efficiently optimise radio resources (rate, power and channel) to guarantee max---min fair capacity to every aggregating Mesh Access Point (MAP). LIRA is composed of a rate adaptation and power control mechanism, sensitive to the fat-tree traffic specificities of WMNs, using the highest bit rates at MAP gateways and using, for the ramified links, the minimum ones that satisfy their capacity needs. This enables to efficiently reduce the transmitted power and interference, advantageous for channel reutilisation. LIRA also integrates a load and interference aware channel assignment mechanism, allowing the simultaneous operation of all links without interference. When this is not achievable, two auxiliary mechanisms of channel sharing and interference-free channel reuse can be sub-sequentially used, reducing the capacity of certain MAPs to guarantee fairness to all nodes. LIRA's gateway flow-control mechanism guarantees that all MAPs respect the allocated capacity, guaranteeing that every MAP is able to operate at its max---min fair capacity. The performance of LIRA is evaluated through simulation, considering IEEE 802.11a. For a classical hexagonal deployment of 19 MAPs with an Internet gateway, it is shown how with only 5 channels LIRA guarantees to every MAP a max---min fair capacity of 3.2 Mbit/s, without packet loss, and delay below 6 ms. It guarantees a max---min fair throughput to every MAP, having a capacity usage efficiency of 66.7 %, an energy efficiency of 26.5 Mbit/J and spectrum efficiency of 0.58 bit/s/Hz. For a more challenging scenario with 27 MAPs and 4 gateways, it is shown how LIRA uses its mechanisms in heterogeneous conditions to also guarantee max---min fair throughput to every MAP, between 5 and 11 Mbit/s, without packet loss, and a delay below 12 ms. Any system improvement will enable to reach higher WMN performance levels using the proposed strategy.

A semi-dynamic, game based and interference aware channel assignment for multi-radio multi-channel wireless mesh networks

Channel assignment CA has been extensively researched for multi-radio wireless mesh networks WMNs, but it is still very challenging when it comes to its implementation. In this paper we propose a semi-dynamic and distributed CA mechanism called semi-dynamic interference aware channel assignment SICA based on game theory formulation. SICA is an interference aware, distributed CA which preserves the network connectivity without relying on a common channel nor central node for coordination between mesh routers. SICA applies a real time learner algorithm which assumes that nodes do not have perfect information about the network topology. To the best of our knowledge this is the first game formulation of CA which takes the co-channel interference into account. We have simulated SICA and compared against other channel assignment mechanisms proposed in the literature. Simulation results show that SICA outperforms other mechanisms.

Interference Aware Channel Assignment Scheme in Multichannel Wireless Mesh Networks

Wireless mesh networks (WMNs) are gaining significant attention to provide wireless broadband service. Nodes in a wireless mesh network can communicate with each other directly or through one or more intermediate nodes. Because of multi-hop transmissions with multiple contending and compet¬ing channels, performance of wireless mesh networks decreases. Supporting high performance is an important challenge in multi-hop mesh networks. Nassiri et al. proposed a Molecular MAC protocol for autonomic assignment and use of multiple channels to improve network performance. In the Molecular MAC protocol, nodes are either nuclei or electrons in an atom. Neighboring atoms use orthogonal channels to operate in parallel data transmissions. Each nucleus selects an idle channel that is not currently being occupied by its neighboring atoms with the assistance from electrons in the same atom. However, this protocol has the following drawback; since a nucleus allocates a channel with help from the electrons in its own transmission range, it is not able to recognize the existence of those atoms in the interference range. Therefore, allocating the same channel to neighboring atoms results in the deterioration of network performance. In order to resolve this problem, we propose a channel allocation scheme with the interference issue taken into account. Based on various simulation results, the proposed scheme was verified that different channels could be allocated to those neighboring atoms in the interference range.

Improving throughput and fairness by improved channel assignment using topology control based on power control for multi-radio multi-channel wireless mesh networks

Multi-radio multi-channel (MRMC) wireless mesh networks (WMNs) achieve higher throughput using multiple simultaneous transmissions and receptions. However, due to limited number of non-overlapping channels, such networks suffer from co-channel interference, which degrades their performance. To mitigate co-channel interference, effective channel assignment algorithms (CAAs) are desired. In this article, we propose a novel CAA, Topology-controlled Interference-aware Channel-assignment Algorithm (TICA), for MRMC WMNs. This algorithm uses topology control based on power control to assign channels to multi-radio mesh routers such that co-channel interference is minimized, network throughput is maximized, and network connectivity is guaranteed. We further propose to use two-way interference-range edge coloring, and call the improved algorithm Enhanced TICA (e-TICA), which improves the fairness among flows in the network. However, the presence of relatively long links in some topologies leads to conflicting channel assignments due to their high interference range. To address this issue, we propose to utilize minimum spanning tree rooted at the gateway to reduce conflicting channels, and in turn, improve medium access fairness among the mesh nodes. We call the improved algorithm e-TICA version 2 (e-TICA2). We evaluate the performance of the proposed CAAs using simulations in NS2. We show that TICA significantly outperforms the Common Channel Assignment scheme in terms of network throughput, and e-TICA and e-TICA2 achieve better fairness among traffic flows as compared to TICA. It is also shown that e-TICA2 leads to improved network throughput, as compared to TICA and e-TICA.

Interference-aware channel assignment in a metropolitan multi-radio wireless mesh network with directional antennas

We investigate the problem of channel assignment in a metropolitan multi-radio wireless mesh network with directional antennas. Our contributions include a new conflict graph model for capturing the interference between links in a mesh network with a known wireless interface communication graph, and a new channel assignment procedure which accounts for interference both between links inside the mesh network, and from external sources. Additionally, we have implemented and evaluated the proposed channel assignment procedure in an actual metropolitan mesh network with 1.6–5 km links. Key components of the channel assignment procedure are the interference model, the link ordering, and the channel selection metric. The experimental results demonstrate how link ordering and the channel selection metric affect performance, in terms of the average packet delay and http latency. The results show that the proposed channel assignment procedure achieves performance very close to a lower bound of the average packet delay, and significantly higher than the performance achieved with a simpler interference-unaware procedure, and a measurement-based scheme that has appeared in the literature, and accounts for interference only from external 802.11 sources. Moreover, we investigate the performance when a different number of channels are available, and the timescales for channel re-assignment.

G-PaMeLA: A divide-and-conquer approach for joint channel assignment and routing in multi-radio multi-channel wireless mesh networks

The performance of Multi-Radio Multi-Channel Wireless Mesh Networks (MRMC-WMNs) based on the IEEE 802.11 technology depends significantly on how the channels are assigned to the radios and how traffic is routed between the access points and the gateways. In this paper we propose an algorithmic approach to this problem, for which, as far as we know, no optimal polynomial time solutions have been put forward in the literature. The core of our scheme consists of a sequential divide-and-conquer technique which divides the overall Joint Channel Assignment and Routing (JCAR) problem into a number of local optimization sub-problems that are executed sequentially. We propose a generalized scheme called Generalized Partitioned Mesh network traffic and interference aware channeL Assignment (G-PaMeLA), where the number of sub-problems is equal to the maximum number of hops to the gateway, and a customized version which takes advantage of the knowledge of the topology. In both cases each sub-problem is formulated as an Integer Linear Programming (ILP) optimization problem. An optimal solution for each sub-problem can be found by using a branch-and-cut method. The final solution is obtained after a post-processing phase, which improves network connectivity. The divide-and-conquer technique significantly reduces the execution time and makes our solution feasible for an operational WMN. With the help of a detailed packet level simulation, the G-PaMeLA technique is compared with several state-of-the-art JCAR algorithms. Our results highlight that G-PaMeLA performs much better than the others in terms of packet loss rate, collision probability and fairness among traffic flows.

Advances in Wireless Mesh Networks

Wireless mesh networks facilitate the extension of wireless local area networks into wide areas and have emerged as a promising approach for future network accesses. Prior efforts on wireless networks, especially multi-hop ad hoc networks, have led to significant research contributions that range from fundamental results on theoretical capacity bounds to numerous practical routing and transport protocols. Unlike ad hoc networks, however, mesh networks can serve as access networks that employ multi-hop wireless forwarding by fixed mesh nodes to relay traffic to and from the wired Internet. The unique features of wireless mesh networks pose challenges in designing affordable, reliable, and sustainable network infrastructures. The critical issues span a rich spectrum of issues from interference-aware channel assignment, multi-hop routing, to reliable transport and infrastructure optimization, many of which have to be revisited in this new context. The purpose of this special issue is to archive the stateof-the-art achievements in wireless mesh networking. We received 30 original and unpublished research papers in both theoretical studies and practical protocol/architecture designs for wireless mesh networks, as well as prototypes. All these papers have gone through a strict peer review process, and among them, 14 high quality papers were selected, which offer a broad and updated coverage of wireless mesh network research and development. In addition, two high-quality papers selected from The Third International Wireless Internet Conference (WICON’2007) are included in this special issue as well. The first two papers of the special issue deal with quality of service (QoS) issue in wireless mesh networks. The paper “Provisioning of Parameterized Quality of Service in 802.11e Based Wireless Mesh Networks,” by Xiaowen Chu, presents a framework for the provisioning of parameterized QoS in 802.11e based wireless mesh networks. By enforcing admission control algorithms and scheduling algorithms, this framework can support constant bit-rate (CBR) and variable bit-rate (VBR) traffic flows. Deterministic endto-end delay bounds for CBR traffic flows and VBR traffic flows that conform to leaky-bucket regulators have been derived. For VBR traffic flows without leaky-bucket regulators, a dynamic transmission opportunity (TXOP) scheduling algorithm has been proposed which was shown to be very effective in achieving high channel utilization ratio while keeping an acceptable delay performance. The paper entitled “QoS Differentiation for IEEE 802.16 WiMax Mesh Networks,” by Yan Zhang, Honglin Hu, and HsiaoMobile Netw Appl (2008) 13:1–5 DOI 10.1007/s11036-008-0055-3

Interference-Aware Channel Assignment in Wireless Mesh Networks

The emerging IEEE 802.11-based Wireless Mesh Networks (WMNs) suffer of poor performance in terms of throughput. The use of multi-hop paths to relay the traffic raises the problems of intra-flow and inter-flow interference in the wireless backbone. A possible solution to this problem is exploiting a multi-channel framework. In this context, we develop an innovative interfere-ence model that permits to take into account the actual signal power received from each interference source, the interference produced by sources external to the WMN, the link utilization factor and directive antennas. Starting from this new model, we propose a channel assignment algorithm for multi-radio WMNs which is based on graph theory. Its performance is evaluated through simulations, which show a great improvement over existing channel assignment algorithms.