Multi-channel Wireless Mesh Networks Research Articles

Analysis of multimedia network data security based on routing algorithm

In today’s society, the application of multimedia data is increasing, and the accompanying data security is also an important issue. This paper will analyze the data security of multimedia network based on routing algorithm. The advantages of wireless local area networks (WLAN) and ad hoc networks are combined in wireless mesh networks (WMNs), which have steadily grown to be a reliable method of wireless broadband access. The application of multi RF and multi-channel technology improves the performance of WMN. However, the limitation that includes the number of wireless network interface cards and channels in the network, results in the great challenges ofrouting and channel allocation in multi RF and multi-channel WMN. Based on AODV algorithm, this paper proposes a new cross layer routing algorithm which is JRCA-AODV algorithm. The simulation results demonstrate that the JRCA-AODValgorithm can successfully increase multiRF multi-channel WMN throughput while lowering packet loss rate and network delay. Take the packet rate of 8 Mbps as an example, the network throughput based on JRCA-AODV algorithm is 1.14 times that of MRMC-AODV algorithm, the packet loss rate based on JRCA-AODV algorithm is 14.06% lower than that of MRMC-AODV algorithm, and the network time delay based on JRCA-AODV algorithm is 14.27% lower than that of MRMC-AODV algorithm. At the same time, JRCA-AODV algorithm can effectively reduce the probability of data loss caused by the competitive and shared access mechanism of the channel, improve the success rate of data transmission, thus reduce the probability of data eavesdropping and tampering in the process of repeated transmission, and improve the security of multimedia network data.This will provide a new direction for promoting the idea of multimedia data security.

A Conflict-Aware Channel Assignment in Multi-Radio Multi-Channel Wireless Mesh Networks

A Conflict-Aware Channel Assignment in Multi-Radio Multi-Channel Wireless Mesh Networks

Multi-channel Scheduling with Interference Avoidance and Precedence Based Algorithm in Wireless Mesh Networks

Wireless Mesh Networks (WMNs) is the wireless networking domain that has been preferentially attracted by many researchers. Multi radio and multichannel WMN has limited channels due to the constraints given by interferences caused internally and externally within the channels. The research is focused on maximizing the performance in multi radio and multi channel WMNs. The channel overlapping that happens partially can overcome this limitation of resources. Interference Avoidance and Precedence Based Algorithm(IAPB) is proposed to reduce the interferences that occur in WMNs and improve the performance.The interference involved during the usage of channels can be reduced by using the channels with less interference. The interference involved is reduced by consideration of precedence level of interference during assignment of channel. The proposed algorithm results in performance improvement in terms of network throughput, the packet loss, delay involved in the reduction of interference.

Inference and performance aware multi-channel scheduling and routing scheme with call admission control in wireless mesh networks

As wireless mesh networks have been deployed in the urban area, dynamic channel allocation is more challengeable because co-located wireless mediums are likely to be tuned to the same channels and may interfere with communication. Further, existing model doesn’t consider reutilizing routing resource. This paper presents an efficient scheduling and routing model considering an external interference and routing resource reutilization for multi-channel wireless mesh networks. Each mesh node uses a novel technique to estimate the usage status of all the channels within its interference range and assigns channels dynamically to radios to minimize interference within the mesh network and between the mesh network and collocated wireless networks. Simulation results demonstrate that our proposed algorithm can improve the network throughput, reduce packet failure rate and consume more energy while transmission substantially compared to other algorithms by removing the interference overestimation problem and assigning channels aggressively with priority.

Coefficient of Restitution based Cross Layer Interference Aware Routing Protocol in Wireless Mesh Networks

In Multi-Radio Multi-Channel (MRMC) Wireless Mesh Networks (WMN), Partially Overlapped Channels (POC) has been used to increase the parallel transmission. But adjacent channel interference is very severe in MRMC environment; it decreases the network throughput very badly. In this paper, we propose a Coefficient of Restitution based cross layer interference aware routing protocol (CoRCiaR) to improve TCP performance in Wireless Mesh Networks. This approach comprises of two-steps: Initially, the interference detection algorithm is developed at MAC layer by enhancing the RTS/CTS method. Based on the channel interference, congestion is identified by Round Trip Time (RTT) measurements, and subsequently the route discovery module selects the alternative path to send the data packet. The packets are transmitted to the congestion free path seamlessly by the source. The performance of the proposed CoRCiaR protocol is measured by Coefficient of Restitution (COR) parameter. The impact of the rerouting is experienced on the network throughput performance. The simulation results show that the proposed cross layer interference aware dynamic routing enhances the TCP performance on WMN.

Internet Traffic based Channel Selection in Multi-Radio Multi-Channel Wireless Mesh Networks

Wireless Mesh Networks(WMNs) are the outstanding technology to facilitate wireless broadband Internet access to users. Routers in WMN have multiple radio interfaces to which multiple orthogonal/partially overlapping channels are assigned to improve the capacity of WMN. This paper is focused on channel selection problem in WMN since proper channel selection to radio interfaces of mesh router increases the performance of WMN. To access the Internet through WMN, the users have to associate with one of the mesh routers. Since most of the Internet Servers are still in wired networks, the major dominant traffic of Internet users is in downlink direction i.e. from the gateway of WMN to user. This paper proposes a new method of channel selection to improve the user performance in downlink direction of Internet traffic. The method is scalable and completely distributed solution to the problem of channel selection in WMN. The simulation results indicate the significant improvement in user performance.

Distributed and Dynamic Channel Assignment Schemes for Wireless Mesh Network

Wireless mesh network (WMN) with wireless backhaul technology provides last-mile Internet connectivity to the end-users. In multi-radio multi-channel WMN (MRMC-WMN), routers provide multiple concurrent transmissions among end-users. The existence of interference among concurrent transmissions severely degrades the network performance. A well-organized channel assignment (CA) scheme significantly alleviates the interference effect. But in trying to minimize interference, the CA scheme may affect the network connectivity. So, the CA scheme has to consider both these two conflicting issues. In this paper, as part of the initial configuration of WMNs, we propose a game theory-based load-unaware CA scheme to minimize the co-channel interference and to maximize the network connectivity. To adapt to the varying network traffic, we propose a dynamic channel assignment scheme. This scheme measures the traffic-load condition of the working channels of each node. Whenever a node finds an overloaded channel, it initiates a channel switch. Channel switching based on the fixed threshold may result in a channel over/underutilization. For optimal channel utilization, we propose a fuzzy logic-based approach to compute the channel switch threshold. The contending nodes and their densities and loads dominantly affect the network capacity and hence the performance. In the context of network capacity enhancement, we have addressed these factors and focused on increasing the network capacity. The simulation results indicate that our proposed load-unaware and load-aware CA schemes outperform the other related load-unaware and load-aware CA approaches.

Comparison of Metaheuristic Algorithms for Interface-Constrained Channel Assignment in a Hybrid Dynamic Spectrum Access – Wi-Fi Infrastructure WMN

In this work, we evaluate the application of four different metaheuristic optimisation algorithms for solving the channel assignment problem in a multi-radio multi-channel Wireless Mesh Network (WMN) using Dynamic Spectrum Access (DSA). The work advances a near optimal channel assignment (CA) in a WMN that uses DSA by applying soft computing methods. While CA in a WMN is well-studied, and CA for secondary user cognitive radio networks has also been studied in the literature, CA for our specific scenario of an infrastructure DSA-WMN is novel. This scenario poses new challenges because nodes are spread out geographically and so may have different allowed channels and experience different levels of external interference in different channels. A solution must meet two conflicting requirements simultaneously: 1) to avoid interference within the network and with external interference sources, and 2) maintain connectivity within the network; all while staying within the radio interface constraint, i.e., only assigning as many channels to a node as it has radios. We present a novel algorithm, used alongside the metaheuristic optimisation algorithms, which ensures the feasibility of solutions in the search space. Average Signal to Interference and Noise Ratio (<inline-formula> <tex-math notation="LaTeX">$SINR$ </tex-math></inline-formula>) over the network is used as the performance measure, with the goal of optimisation being to find the highest average <inline-formula> <tex-math notation="LaTeX">$SINR$ </tex-math></inline-formula>. This is a more realistic performance measure than the binary on/off conflict-based measures most common in the literature. Our energy-based method also has the unique advantage that it is protocol-agnostic, being able to avoid interference from external sources that use different protocols and standards. The algorithms that are compared in this work are Simulated Annealing (SA), the Genetic Algorithm (GA), Particle Swarm Optimisation (PSO), and Differential Evolution (DE). These algorithms were evaluated through the use of simulation in Network Simulator 3. Various parameters were experimented with for each of the employed algorithms. The resultant best set of parameters was used for the comparison of the four metaheuristic algorithms. It was found that the population-based algorithms (PSO, GA, and DE) all perform satisfactorily for this problem, although DE is superior to the others. SA can give acceptable solutions, but performs poorly in comparison to the population-based algorithms. The paper also considers the computational complexity of the methods. It is found that SA and DE perform well in this regard.

Channel Assignment Based on CSMA-Aware Interference Model With Overlapped Channels in Multiradio Multichannel Wireless Mesh Networks

Multi-radio Multi-channel Wireless Mesh Networks (MRMC WMNs) implemented on IEEE 802.11 standards are widely used owing to their adaptability in practical network scenarios. The channel assignment problem in MRMC WMNs has been extensively studied. However, in most of the existing works, only orthogonal wireless channels are considered owing to the complexity of the channel assignment problem, which results in a low level of spatial utilization. This paper introduces partially overlapping channels into the CSMA-aware interference and shared link capacity models to fully exploit the spectrum resource and improve network capacity, utilizing both orthogonal channels and partially overlapping channels in IEEE 802.11 2.4 GHz bands. We formulate this problem as a mixed-integer linear program (MILP). We propose a traffic-demand-aware collision-free partially overlapping channel assignment (TAC-POCA), which uses all the available channels and achieves collision-free end-to-end flow transmissions to attain load balance. Simulation results show that TAC-POCA leads to better utilization of the spectrum resource and throughput improvement in both grid and random topology networks than in the case of using only orthogonal channels.

Link Interference and Route Length Based Dynamic Channel Allocation Algorithm for Multichannel Wireless Mesh Networks

In this paper, the theoretical analysis showed that the length of the route and the interference of links were the main factors that influence the throughput of the network. Then, a dynamic channel allocation algorithm base on the length of routes and the interference of links was proposed to enhance the system throughput. In the proposed algorithm, ant colony algorithm was used to collect the information of network, such as the length of routes and the interference of links. Then, the priority of link access channel was decided according to the collected information. The simulation results showed that the proposed algorithm could improve the whole network throughput obviously.

Distributed optimal congestion control and channel assignment in wireless mesh networks

Wireless mesh networks have numerous advantages in terms of connectivity as well as reliability. Traditionally the nodes in wireless mesh networks are equipped with single radio, but the limitations are lower throughput and limited use of the available wireless channel. In order to overcome this, the recent advances in wireless mesh networks are based on multi-channel multi-radio approach. Channel assignment is a technique that selects the best channel for a node or to the entire network just to increase the network capacity. To maximize the throughput and the capacity of the network, multiple channels with multiple radios were introduced in these networks. In the proposed system, algorithms are developed to improve throughput, minimise delay, reduce average energy consumption and increase the residual energy for multi radio multi-channel wireless mesh networks. In literature, the existing channel assignment algorithms fail to consider both interflow and intra flow interferences. The limitations are inaccurate bandwidth estimation, throughput degradation under heavy traffic and unwanted energy consumption during low traffic and increase in delay. In order to improve the performance of the network distributed optimal congestion control and channel assignment algorithm (DOCCA) is proposed. In this algorithm, if congestion is identified, the information is given to previous node. According to the congestion level, the node adjusts itself to minimise congestion.

Achieving Hidden-Terminal-Free Channel Assignment in IEEE802.11-Based Multi-Radio Multi-Channel Wireless Mesh Networks

Achieving Hidden-Terminal-Free Channel Assignment in IEEE802.11-Based Multi-Radio Multi-Channel Wireless Mesh Networks

Adaptive Allocation Algorithm for Multi-Radio Multi-Channel Wireless Mesh Networks

The wireless mesh network (WMN) has proven to be a great choice for network communication technology. WMNs are composed of access points (APs) that are installed and communicate with each other through multi-hop wireless networks. One or more of these APs acts as a gateway (GW) to the internet. Hosts of WMNs are stationary or mobile. According to the structure of WMNs, some network features may be affected, such as the overall performance, channel interference, and AP connectivity. In this paper, we propose a new adaptive channel allocation algorithm for a multi-radio multi-channel wireless mesh network. The algorithm is aimed to minimize the number of channel reassignments while maximizing the performance under practical constraints. The algorithm defines a decision function for the channel reassignments. The decision function aims to minimize the traffic around the GW. Whenever the traffic changes in the wireless mesh network, the decision function decides which channel radio reassignment should be done. We demonstrated the effectiveness of our algorithm through extensive simulations using Network Simulator 2 (NS-2).

EMSC: a joint multicast routing, scheduling, and call admission control in multi-radio multi-channel WMNs

This paper deals with the problem of joint multicast routing, scheduling, and call admission control in multiradio multi-channel wireless mesh networks. To heuristically solve this problem, we propose a cross-layer algorithm named “extended MIMCR with scheduling and call admission control phases (EMSC)”. Our model relies on the on-demand quality of service (QoS) multicast sessions, where each admitted session creates a unique tree with a required bandwidth. The proposed scheme extends the MIMCR algorithm to fairly schedule multiple non-interfering transmissions in the same time slot. It also exploits a call admission control mechanism to protect the QoS requirements of the multicast traffics. EMSC reduces the number of occupied time slots, with consideration of spatial reuse, both Intra-flow and Inter-flow interferences, and selecting the minimum-interference minimum-cost paths. This subsequently leads to better radio resource utilization and increases the network throughput. Simulation results show that the proposed algorithm outperforms the other algorithms and improves the network performance.

Maximize concurrent data flows in multi-radio multi-channel wireless mesh networks

Multi-radio multi-channel (MRMC) wireless mesh networks (WMNs) have emerged as the broadband networks to provide access to the Internet for ubiquitous computing with the support for a large number of data flows. Many applications in WMNs can be abstracted as a multi-flow coexistence problem to carry out multiple concurrent data transfers. More specifically, links in different channel layers must be concatenated to compose multiple data transfer paths based on nodes? free interfaces and available channels. This is typically formulated as a combinatorial optimization problem with various stages including channel assignment, path computing, and link scheduling. This paper analyzes traffic behaviors and designs a coexisting algorithm to maximize the number of concurrent data flows. Simulations are conducted in combinatorial cases of channel and radio with various traffic requests of multiple pairs. The experimental results show the efficacy of the coexisting algorithm over a randomly generated topology. This scheme can be used to develop routing and scheduling solutions for various multi-flow network applications through prior computing.

Dynamic Channel Assignment and Gateway Load Balanced Routing for Multi-Channel Wireless Mesh Networks

Dynamic Channel Assignment and Gateway Load Balanced Routing for Multi-Channel Wireless Mesh Networks

MO‐CSO‐based load‐balanced routing in MRMC WMN

The multi-radio–multi-channel wireless mesh networks (MRMC WMNs) have attracted much attention due to their low cost, reliable coverage, stable topology, and so forth. Load balancing among gateways (GWs) is a challenging task in MRMC WMNs. The GW nodes with higher loads will lead to disconnected network. GW and shortest path selection may increase traffic concentration which leads to congestion and collision in network. In this study, a multi-objective competitive swarm optimiser (MO-CSO) with analytic hierarchy process-based (AHP) load-balancing technique is proposed among the multiple GW nodes that provide communication between server and user to select the lightly loaded GWs, so that more packets will be delivered to the fixed host in Internet. The proposed method selects four GW parameters that are GW connecting degree, GW capacity indicator, traffic in collision domain, and path cost. The objective functions are minimisation of delay and maximising the channel utilisation, network throughput, and balancing network traffic. The MO-CSO with AHP method is utilised to select the best GW and path which combines all four parameters. Simulation results show that the proposed MO-CSO improves the network performance by maximum throughput while compared with the existing routing strategies such as SBR, ETX, LG, NG, and IR.

Internet Traffic based Channel Selection in Multi-Radio Multi-Channel Wireless Mesh Networks

Wireless Mesh Networks(WMNs) are the outstanding technology to facilitate wireless broadband Internet access to users. Routers in WMN have multiple radio interfaces to which multiple orthogonal/partially overlapping channels are assigned to improve the capacity of WMN. This paper is focused on channel selection problem in WMN since proper channel selection to radio interfaces of mesh router increases the performance of WMN. To access the Internet through WMN, the users have to associate with one of the mesh routers. Since most of the Internet Servers are still in wired networks, the major dominant traffic of Internet users is in downlink direction i.e. from the gateway of WMN to user. This paper proposes a new method of channel selection to improve the user performance in downlink direction of Internet traffic. The method is scalable and completely distributed solution to the problem of channel selection in WMN. The simulation results indicate the significant improvement in user performance.

Performance Analysis on Hybrid Wireless Mesh Network Topology using Interference Aware Bandwidth Reservation

Ubiquitous of modern era which utilises Hybrid Wireless Mesh Network (HWMN) topology which gave birth to ample of modern application which demands reliability, fault tolerance and scalability. HWSN topology utilises minimum of two or multiple standard network architectural topologies, in a fashion that the resultant network architecture doesn’t depict any particular topologies like bus, star or ring but as a combination of any of those standard topologies. Prime motive of the proposed Optimised Channel Assignment Algorithm (OCSA) is which focuses on priority oriented interference minimization for all the trees which are existed, and constraint in terms of delay for evolving tree addition. Interference Aware Bandwidth Reservation (IABR) provides controllability over data flow admission for end-to-end optimal bandwidth accommodation in Multi-Radio Multi-Channel (MRMC) wireless mesh network. Proposed Priority Based Interference Aware Bandwidth Reservation (PBIABR) utilises disseminated and polynomial-time heuristic oriented assignment in channel to minimize interference in WMN with the awareness of channel priority as a primary consideration. Interference and Priority of the channel are made indirectly proportional to each other. For the channel of high priority the path which has low interference is opted. In PBIABR the whole path delay constraint of tree is sub organised into multiple node, based on delay to identify the best node which embodies minimal interference. Dominant Performance Parameters (DPP) like Throughput, Packet Size, Propagation Interval and Average Energy under HWSN Scenario. All the DPP parameters are analysed for multiple flow parameters for Interference Aware Bandwidth Reservation (IABR) and Proposed Priority Based Interference Aware Bandwidth Reservation (PBIABR) conditions. Simulation results have been captured using Network Simulator 2 tools for HWSN creation and crafted to same readings as a graph for deep analysis. The proposed simulation results for hybrid scenario highlights a considerable performance hike for the performance parameters like Throughput (bps) vs Packet size (bytes), Average Energy (joule) vs Interval (sec) and Residual Energy (joule) vs Interval (sec) under PBIABR conditions compared with IABR simulation outcome. The results have been analysed for comparative study of each parameter deeply. Inference from the comparative analysis highlights the performance parameters of PBIABR is efficient than IABR.

Online multicast tree construction with bandwidth and delay constraints in multi-channel multi-radio wireless mesh networks

This paper deals with online QoS multicast tree construction problem, which is essential to support multimedia services, in multi-channel multi-radio wireless mesh networks. The proposed algorithm satisfies both delay and bandwidth requirements of each arrived session. It breaks down the original problem into two phases of satisfying delay and bandwidth constraints. The first phase devotes to preserving delay constraint of the arrived session, in which a number of delay-bounded paths are determined between each receiver and the source node. In the proposed scheme, to diminish the utilized bandwidth, the overlapping of the regarding paths of the receivers is maximized as much as possible. We propose a mathematical model to satisfy bandwidth requirement in the second phase, which constructs the tree over the selected paths. The data transmission rate on the tree is set to the requested rate by the session, to satisfy its bandwidth requirement. The proposed model has a global view over the network and constructs the most appropriate trees. It also exploits wireless broadcast advantage property to enhance the performance. Through extensive simulations, the effectiveness of the proposed algorithm is verified. In particular, it improves the acceptance rate by 60% compared to previous schemes.