Modelling a Learning-Based Dynamic Tree Routing Model for Wireless Mesh Access Networks

Link asymmetry in wireless mesh access networks(WMAN)of Mobile ad-hoc Networks(MANETs)is due mesh routers’transmission range.It is depicted as significant research challenges that pose during the design of network protocol in wireless networks.Based on the extensive review,it is noted that the substantial link percentage is symmetric,i.e.,many links are unidirectional.It is identified that the synchronous acknowledgement reliability is higher than the asynchronous message.Therefore,the process of establishing bidirectional link quality through asynchronous beacons underrates the link reliability of asym-metric links.It paves the way to exploit an investigation on asymmetric links to enhance network functions through link estimation.Here,a novel Learning-based Dynamic Tree routing(LDTR)model is proposed to improve network performance and delay.For the evaluation of delay measures,asymmetric link,interference,probability of transmission failure is evaluated.The proportion of energy consumed is used for monitoring energy conditions based on the total energy capacity.This learning model is a productive way for resolving the routing issues over the network model during uncertainty.The asymmetric path is chosen to achieve exploitation and exploration iteratively.The learning-based Dynamic Tree routing model is utilized to resolve the multi-objective routing problem.Here,the simulation is done with MATLAB 2020a simulation environment and path with energy-efficiency and lesser E2E delay is evaluated and compared with existing approaches like the Dyna-Q-network model(DQN),asymmetric MAC model(AMAC),and cooperative asymmetric MAC model(CAMAC)model.The simulation outcomes demonstrate that the anticipated LDTR model attains superior network performance compared to others.The average energy consump-tion is 250 J,packet energy consumption is 6.5 J,PRR is 50 bits/sec,95%PDR,average delay percentage is 20%.

Error resilient concurrent video streaming over wireless mesh networks

In this paper, we propose a multi-source multi-path video streaming system for supporting high quality concurrent video-on-demand (VoD) services over wireless mesh networks (WMNs), and leverage forward error correction to enhance the error resilience of the system. By taking wireless interference into consideration, we present a more realistic networking model to capture the characteristics of WMNs and then design a route selection scheme using a joint rate/interference-distortion optimiza- tion framework to help the system optimally select concurrent streaming paths. We mathematically formulate such a route selec- tion problem, and solve it heuristically using genetic algorithm. Simulation results demonstrate the effectiveness of our proposed scheme.

SLCRM： Subjective Logic-Based Cross-Layer Reputation Mechanism for Wireless Mesh Networks

Wireless Mesh Networks (WMNs) are vulnerable to various security threats because of their special infrastructure and communication mode, wherein insider attacks are the most challenging issue. To address this problem and protect innocent users from malicious attacks, it is important to encourage cooperation and deter malicious behaviors. Reputation systems constitute a major category of techniques used for managing trust in distributed networks, and they are effective in characterizing and quantifying a node's behavior for WMNs. However, conventional layered reputation mechanisms ignore several key factors of reputation in other layers; therefore, they cannot provide optimal performance and accurate malicious node identification and isolation for WMNs. In this paper, we propose a novel dynamic reputation mechanism, SLCRM, which couples reputation systems with a cross-layer design and node-security-rating classification techniques to dynamically detect and restrict insider attacks. Simulation results show that in terms of network throughput, packet delivery ratio, malicious nodes identification, and success rates, SLCRM implements security protection against insider attacks in a more dynamic, effective, and efficient manner than the subjective logic and uncertainty-based reputation model and the familiarity-based reputation model.

Multi-path based secure communication in wireless mesh networks

Communication security is a critical aspect of QoS provisioning in wireless mesh network （WMN）. Because of the inherent characteristics of WMN, conventional security mechanisms cannot be applied. In order to guarantee the communication security, a novel communication security mechanism is proposed. The mechanism uses a communication encryption scheme to encrypt data packets and employs a risk avoidance scheme to avoid the malicious nodes during communications. Simulation results indicate that the mechanism is able to provide secure communication effectively and reduce the damage of attacks through multiple paths.

Gateways Placement in Backbone Wireless Mesh Networks

This paper presents a novel algorithm for the gateway placement problem in Backbone Wireless Mesh Networks (BWMNs). Different from existing algorithms, the new algorithm incrementally identifies gateways and assigns mesh routers to identified gateways. The new algorithm can guarantee to find a feasible gateway placement satisfying Quality-of-Service (QoS) constraints, including delay constraint, relay load constraint and gateway capacity constraint. Experimental results show that its performance is as good as that of the best of existing algorithms for the gateway placement problem. But, the new algorithm can be used for BWMNs that do not form one connected component, and it is easy to implement and use.

Evaluation of Energy Consumption of Proactive, Reactive, and Hybrid Routing Protocols in Wireless Mesh Networks Using 802.11 Standards

This paper provides a deep evaluation of the energy consumption of routing protocols. The evaluation is done along with other metrics such as throughput and packet delivery ratio (PDR). We introduce two more metrics to capture the efficiency of the energy consumption: e-throughput and e-PDR. Both are ratios in relation to the energy. We consider the three low layers of the stack. Three types of routing protocols are used: proactive, reactive, and hybrid. At the MAC and PHY layer, three radio types are considered: 802.11a/b/g. Finally, the number of nodes is varying in random topologies, with nodes being static or mobile. Simulations are conducted using NS3. The parameters of a real network interface card are used. From the results in mobile position scenarios, no protocol is outperforming the others;even if OLSR has the lowest energy consumption, most of the time. However, in constant position scenarios, AODV consumed a lower energy, apart from the scenarios using the 802.11a standard where HWMP energy consumption is the lowest. Regarding the energy efficiency, AODV protocols provided the best e-throughput and OLSR the best e-PDR in overall configurations. A framework for selecting energy-efficient routing protocol depending on network characteristics is proposed at the end.

Centralized Quasi-Static Channel Assignment for Multi-Radio Multi-Channel Wireless Mesh Networks

Employing multiple channels in wireless multihop networks is regarded as an effective approach to increas-ing network capacity. This paper presents a centralized quasi-static channel assignment for multi-radio multi-channel Wireless Mesh Networks (WMNs). The proposed channel assignment can efficiently utilize multiple channels with only 2 radios equipped on each mesh router. In the scheme, the network end-to-end traffics are first modeled by probing data at wireless access points, and then the traffic load between each pair of neighboring routers is further estimated using an interference-aware estimation algorithm. Having knowledge of the expected link load, the scheme assigns channels to each radio with the objective of mini-mizing network interference, which as a result greatly improves network capacity. The performance evalua-tion shows that the proposed scheme is highly responsive to varying traffic conditions, and the network per-formance under the channel assignment significantly outperforms the single-radio IEEE 802.11 network as well as the 2-radio WMN with static 2 channels.

Wireless Mesh Networks and Cooperative Relaying Technologies

The Wireless Mesh Network (WMN) has become a focus in research of wireless broadband communications . In a switching technologies - based wireless Mesh network, the entire network is regarded as an IP subnet, so it cannot be applied in situations where large coverage is required . The use of cooperative relaying technologies can improve the transmission rate and reliability of wireless link; while the wireless Mesh network, once integrated with cooperative relaying technologies and routing technologies , can improve its spectrum efficiency and cover a wide area . However, there are many problems to be solved with respect to standardization, key technologies research and industrialization. Therefore , the application of cooperative relaying technologies in wireless Mesh networks is still a great challenge .

A TRUST MECHANISM-BASED CHANNEL ASSIGNMENT AND ROUTING SCHEME IN COGNITIVE WIRELESS MESH NETWORKS WITH INTRUSION DETECTION

Cognitive Wireless Mesh Networks(CWMN) is a novel wireless network which combines the advantage of Cognitive Radio(CR) and wireless mesh networks.CWMN can realize seamless in-tegration of heterogeneous wireless networks and achieve better radio resource utilization.However,it is particularly vulnerable due to its features of open medium,dynamic spectrum,dynamic topology,and multi-top routing,etc..Being a dynamic positive security strategy,intrusion detection can provide powerful safeguard to CWMN.In this paper,we introduce trust mechanism into CWMN with intrusion detection and present a trust establishment model based on intrusion detection.Node trust degree and the trust degree of data transmission channels between nodes are defined and an algorithm of calcu-lating trust degree is given based on distributed detection of attack to networks.A channel assignment and routing scheme is proposed,in which selects the trusted nodes and allocates data channel with high trust degree for the transmission between neighbor nodes to establish a trusted route.Simulation re-sults indicate that the scheme can vary channel allocation and routing dynamically according to network security state so as to avoid suspect nodes and unsafe channels,and improve the packet safe delivery fraction effectively.

Design and analysis of intrusion detection systems for wireless mesh networks

Intrusion is any unwanted activity that can disrupt the normal functions of wired or wireless networks. Wireless mesh networking technology has been pivotal in providing an affordable means to deploy a network and allow omnipresent access to users on the Internet. A multitude of emerging public services rely on the widespread, high-speed, and inexpensive connectivity provided by such networks. The absence of a centralized network infrastructure and open shared medium makes WMNs particularly susceptible to malevolent attacks, especially in multihop networks. Hence, it is becoming increasingly important to ensure privacy, security, and resilience when designing such networks. An effective method to detect possible internal and external attack vectors is to use an intrusion detection system. Although many Intrusion Detection Systems (IDSs) were proposed for Wireless Mesh Networks (WMNs), they can only detect intrusions in a particular layer. Because WMNs are vulnerable to multilayer security attacks, a cross-layer IDS are required to detect and respond to such attacks. In this study, we analyzed cross-layer IDS options in WMN environments. The main objective was to understand how such schemes detect security attacks at several OSI layers. The suggested IDS is verified in many scenarios, and the experimental results show its efficiency.

Scalability Technologies for Wireless Mesh Networks

The continuous increase of data transmission density in wireless mobile communications has posed a challenge to the system performance of Wireless Mesh Networks (WMNs ). There is a rule for wireless Ad hoc networks that the average node capacity decreases while the number of nodes increases , so it is hard to establish a large - scale wireless Mesh network. Network scalability is very important for enhancing the adaptive networking capability of the wireless Mesh network. This article discusses key scalability technologies for Mesh Base Stations (BSs ) and Mesh Mobile Stations (MSs ), such as channel allocation, intelligent routing , multi- antenna , node classification, Quality of Service (QoS) differentiation and cooperative transmission.

IEEE 802.11s Wireless Mesh Networks for Last-Mile Internet Access: An Open-Source Real-World Indoor Testbed Implementation

Due to their easy-to-deploy and self-healing features, WMNs (Wireless Mesh Networks) are emerging as a new promising technology with a rich set of applications. While the IEEE standardization of this new technology is still in progress, its main traits are already set, e.g., architecture and MAC routing. WMNs are attracting considerable research in academia and industry as well, but the lack of open-source testbeds is restricting such a research to simulation tools. The main problem with simulation tools is that they do not reflect the complexity of RF propagation, especially in indoor environments, of which IEEE 802.11s WMNs are an example. This paper presents an open-source implementation of an indoor IEEE 802.11s WMN testbed. The implementation is transparent, easy-to-deploy, and both the source code and deployment instructions are available online. The implementation can serve as a blueprint for the WMN research community to deploy their own testbeds, negating the shortcomings of using simulation tools. By delving into the testbed implementation subtleties, this paper is shedding further light on the details of the ongoing IEEE 802.11s standard. Major encountered implementation problems (e.g., clients association, Internetworking, and supporting multiple gateways) are identified and addressed. To ascertain the functionality of the testbed, both UDP and TCP traffic are supported and operational. The testbed uses the default IEEE 802.11s HWMP (Hybrid Wireless Mesh Protocol) routing protocol along with the default IEEE 802.11s Airtime routing metric.

Survivable Routing Protocol for Green Wireless Mesh Networks Based on Energy Efficiency

This paper proposes a new Energyefficient Survivable Routing Protocol(ESRP)based on solar energy and wind mixed for power supply in green wireless mesh networks(WMNs).The ESRP combines hop penalty strategy and flooding delaying strategy to improve the performances of traditional routing protocol.This paper uses QualNet to simulate and verify the performances of proposed ESRP.Compared with the traditional routing protocol,the simulation results show that the energy utilization of ESRP is more efficient by 13%.At the same time,ESRP is more load-balanced to postpone the appearance of the first energy depletion node and reduce the number of energy depletion nodes,and thus it effectively improves network survivability.

Incorporating Network Coding into TCP Grounded on Network Utility Maximization in Multi-Radio Multi-Channel Wireless Mesh Networks

A new approach, named TCP-I2NC, is proposed to improve the interaction between network coding and TCP and to maximize the network utility in interference-free multi-radio multi-channel wireless mesh networks. It is grounded on a Network Utility Maxmization (NUM) formulation which can be decomposed into a rate control problem and a packet scheduling problem. The solutions to these two problems perform resource allocation among different flows. Simulations demonstrate that TCP-I2NC results in a significant throughput gain and a small delay jitter. Network resource is fairly allocated via the solution to the NUM problem and the whole system also runs stably. Moreover, TCP-I2NC is compatible with traditional TCP variants.

AN ADAPTIVE OPPORTUNISTIC RETRANSMISSION CONTROL SCHEME ENVIRONMENT-AWARE-BASED FOR WIRELESS MULTIMEDIA MESH NETWORKS

In this paper, we propose an aware-based adaptive opportunistic retransmission control scheme for wireless multimedia Mesh networks. The proposed scheme provides maximum retransmis-sion count optimization based on environment-aware to improve packet relay probability. The scheme discriminates the types of packet loss in wireless link by means of environment information and selects the retransmission count by taking the IEEE 802.11 wireless channel characteristics into consideration. Furthermore, the maximum retransmission count of MAC is adjusted adaptively. Extensive simulations demonstrate that the proposed scheme significantly reduces packet collision probability and packet loss rate, and thus improves network throughput.

Cross-Layer Design Based Optimized Link State Routing Protocol for Wireless Mesh Networks

A proactive routing protocol CL-OLSR （cross-layer based optimized link state routing） by using a brand-new routing metric CLM （cross-layer metric） is proposed. CL-OLSR takes into account four link quality impact factors in route calculation through the cross-layer operation mechanism： the node available bandwidth, the node load, the link delivery rate, and the link interference, and thus the effect of route selection is optimized greatly. The simulation results show that the proposed CL-OLSR protocol can not only improve the network throughput to a large extent, but also reduce the end-to-end delay, while achieving load balance route results.

An Efficient Routing Tree Algorithm for Combined Uplink and Downlink Subframes on Centralized Scheduling in IEEE 802.16 Based Wireless Mesh Networks

IEEE 802.16 mesh mode defines routing tree for transmitting data in centralized scheduling but it does not define any explicit proposal for combining uplink and downlink subframes. Deploying combined uplink and downlink subframes on the centralized scheduling scheme can be more flexible and utilization is improved. However, existing interferences among the transmission of neighboring nodes lead to performance reduction of the network. In this paper, an efficient routing tree algorithm is proposed with combined uplink and downlink slot allocation on the centralized scheduling scheme which can abate interferences in the network. This algorithm allows more subscriber stations to transmit concurrently and so improves spatial reuse in the network. Also, the algorithm uses multi-channel and single channel systems and considers relay model, smoothing switching frequently between transmitting and receiving in successive time slots and fairness in the network. Extensive simulation results demonstrate the effectiveness of the proposed method in terms of scheduling length, link concurrency ratio, network throughput and Channel Utilization Ratio (CUR).

Utilizing Colored Pheromones and Helping Ants for Wireless Mesh Networks Routing

Improving routing algorithm performance not only leads to appreciate the quality of data transmission, but also increases the speed of data transfer. In this paper we propose a hybrid method which is a combination of traffic classification by the help of colored pheromones and helping ants method in the intermediate nodes. This combination increases the convergence speed and decreases the delay and Jitter in the network. Also we compare the obtained results with two known routing algorithms that are based on the ant colony.

Streaming Multimedia over Wireless Mesh Networks

Wireless mesh network (WMN) research is an emerging field in network communications. However, WMNs pose several difficulties in the transmission of information, especially time critical applications such as streaming video and audio. In this paper, we provide an overview of several research papers which utilize mesh networks for streaming multimedia. We compare the results of the research and the significance they bring to the field of wireless mesh networks. We then provide possible directions for future research into wireless mesh networks as they apply to streaming multimedia.