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Multi-hop wireless mesh networks (M-WMNs) [Akyildiz, I. F., 2005] are one of the key features of beyond 3G systems because of their flexibility and low-cost deployment. So far, most of existing studies on multi-hop wireless mesh networks have been accomplished based on the IEEE 802.11 ad hoc mode. The IEEE 802.16 working group (WG) specified the IEEE 802.16-2004 standard [IEEE Std. 802.16-2004, 2004] in October 2004 and the standard defined two modes: the point-to-multi-point (PMP) mode and the mesh mode. The IEEE 802.16 mesh standard defines three mechanisms to schedule the data transmission: centralized scheduling (CSCH) [Morge, P. S., 2007], [Han, B., 2007], coordinated distributed scheduling (C-DSCH) [Morge, P. S., 2007], and uncoordinated distributed scheduling (UnDSCH). In the IEEE 802.16 mesh mode with the CSCH, C-DSCH, and Un-DSCH, multi-hop communication is possible between nodes such as mesh base stations (MeshBSs) and mesh subscriber stations (MeshSSs) because all nodes are peers and each node can act as routers to support multi-hop packet forwarding. In particular, in the IEEE 802.16 mesh mode with the C-DSCH, every node competes for channel access using a distributed election algorithm (DEA) based on the scheduling information of the extended neighborhoods (one-hop and two-hop neighbors) in a completely distributed manner and reserves radio resource by a three-way handshaking mechanism in which nodes request, grant, and confirm available radio resource using mesh distributed scheduling (MSH-DSCH) message. Like this, because the IEEE 802.16 mesh mode with the C-DSCH has good flexibility and scalability, it is suitable as an alternative medium access control (MAC) protocol for establishing M-WMNs. For M-WMNs to serve as a wireless network infrastructure, the protocol design for M-WMN should target a high network throughput. In the IEEE 802.16 mesh mode with the C-DSCH, after occupying radio resource, a node cannot transmit any MSH-DSCH message for a holdoff time in order to share radio resource with other nodes in M-WMN. If nodes get a short holdoff time in a heavily loaded network situation, the competition between nodes will happens severe and thus they will experience long contention times before reserving radio resource. On the other hand, if nodes get a long holdoff time in a lightly loaded

Wireless sensor network are emerging in various fields like environmental monitoring, mining, surveillance system, medical monitoring. LEACH protocol is one of the predominantly used clustering routing protocols in wireless sensor networks. In Leach each node has equal chance to become a cluster head which make the energy dissipated of each node be moderately balanced. We have pioneered an improved algorithm named as Novel Leach based on Leach protocol. The proposed algorithm shows the significant improvement in network lifetime .Comparison of proposed algorithm is done with basic leach in terms of network life time, cluster head selection, energy consumption, and data transmission to base station. The simulation results shows that proposed algorithm can reduce network energy consumption and prolong network life commendably. Simulation of our protocol is done with Matlab.

In this paper, a fast and efficient handover authentication protocol is proposed. It is considered as a solution to the performance problem of IEEE802.11s Wireless mesh networks (WMNs). Actually, it suffers from long handover delay time, which is unsuitable for the mobility in WMNs. The proposed protocol presents a new and secure method to reduce the handover time based on the ticket authentication. Since Mesh STA User ( MU ) is directly authenticated by the Mesh Access Points ( MPs ), without involving the Authentication Server ( AS ). Furthermore, a new design of the ticket is presented. The security analysis proves the efficiency of the presented protocol against the known types of attacks. A security test is carried out on the proposed protocol using the formal verification tool, AVISPA, which declares that the presented protocol is secure. The performance analysis proves that a significant improvement in computation and communication overhead is achieved. Moreover, the presented scheme satisfies good privacy preservation. A simple network simulation is carried out, which confirms the results of the performance analysis.

Design optimization for reliable networking is necessary for Ethernet ring mesh networks with ITU-T G.8032 Ethernet ring protection recommendation or with the IEC 62439-3 high-availability seamless redundancy protocol. To achieve this goal, the precise analysis of reliability/availability in Ethernet ring mesh consisting of single or multiple rings is one of the basic needs. Calculation of network reliability in these networks is an NP-hard problem. Therefore, most of the reliability and availability analyses were based on approximation and inaccurate methods. In this paper, at first, using decomposition method, a careful reliability analysis of Ethernet single-ring mesh networks will be presented. In addition, an accurate analysis of the reliability of Ethernet multiple-ring mesh networks will be performed by a novel approach named the spanning tree set method. Then, the availability of the ring networks with imperfect coverage and online repair assumptions will be analyzed using a hierarchical model in which each subsystem is modeled as a series system of independent Markov components.

Cooperative channel allocation and scheduling are key issues in wireless mesh networks with multiple interfaces and multiple channels. In this paper, we propose a load balance link layer protocol (LBLP) aiming to cooperatively manage the interfaces and channels to improve network throughput. In LBLP, an interface can work in a sending or receiving mode. For the receiving interfaces, the channel assignment is proposed considering the number, position and status of the interfaces, and a task allocation algorithm based on the Huffman tree is developed to minimize the mutual interference. A dynamic link scheduling algorithm is designed for the sending interfaces, making the tradeoff between the end-to-end delay and the interface utilization. A portion of the interfaces can adjust their modes for load balancing according to the link status and the interface load. Simulation results show that the proposed LBLP can work with the existing routing protocols to improve the network throughput substantially and balance the load even when the switching delay is large.

In multi-hop wireless networks, minimizing the transmission time is very important. In this paper, a high-reliability relay algorithm (HRRA) is proposed to decrease the transmission time based on the network coding in multi-rate environment. The HRRA includes the relay selection algorithm (RSA) and the block transmission algorithm (BTA). Based on the relay reliability of node, RSA chooses the neighbor with the higher link rate as the common relay node and creates more network coding opportunities at the common relay node. Thus, the network coding opportunities and the high-rate links associated with common node could both be exploited in the transmissions of BTA. Moreover, a comprehensive theoretical analysis of the transmission time of HRRA in a block is presented. Lastly, the simulation results show that HRRA can significantly reduce the transmission time compared with the shortest path algorithm and heuristic relay node selection algorithm and COPE.

A privacy-aware, secure and energy-aware green routing (PSGR) scheme was proposed.The PSGR defends against internal attacks and achieves strong privacy protection.The PSGR integrates a dynamic reputation mechanism and a key management protocol. Hybrid Wireless Mesh Networks (HWMNs) were proposed to address the challenges in wireless communications to support mobile applications across different domains. Due to the multi-hop and decentralized network architecture, HWMNs are naturally susceptible to various security threats, especially internal attacks. Therefore, HWMNs must be able to detect anomalies, provide secure routing and protect user privacy through the cooperation among nodes. However, the existing routing protocols for HWMNs cannot ensure the security to protect the users privacy effectively. Moreover, traditional HWMNs are vertically integrated where the control and data planes of mesh routers are bundled together, which makes it complex and difficult to configure the network according to predefined security policies, and to adaptively respond to various dynamic security threats. Software-Defined Wireless Mesh Networks decouple the control plane and data plane of routers and thus enable a more flexible and efficient configuration of security policies. Taking up this opportunity to address the aforementioned challenges, this paper proposes a privacy-aware, secure and energy-aware green routing (PSGR) protocol that can defend against internal attacks, achieve stronger privacy protection and reduce energy consumption in Software-Defined HWMNs. The elaborate theoretical analysis verify that the PSGR protocol can implement the security and privacy protection against internal attacks effectively and efficiently. Simulation results demonstrate a superior performance of PSGR in terms of packet delivery ratio, network throughput and energy efficiency compared to the existing PA-SHWMP, PASER, and HWMP protocols in the presence of Blackhole/Grayhole attacks and wormhole attacks. Display Omitted

In recent years, building the cloud based on wireless mesh networks as well as wired networks is rapidly increased for processing the big data. However, existing scheduling and routing protocols cannot support processing the big data efficiently in the cloud, because the each flow path is determined before the data are transmitted based on some routing strategies in the wireless mesh networks. Currently, an important factor that should be considered is that the link capacity between mesh routers can be changed based on the current interference of the flow of other mesh routers. In general, network availability is also influenced by the interference related to the other layers in the protocol stack. In this paper, we study wireless mesh networks and propose JRS-S and JRS-M algorithms, which utilize both route discovery and resource allocation at the same time, in order to maximize capacity of the wireless mesh network in the cloud computing. Our algorithms for each flow use a cross-layer design method based on numerical modeling in order to adaptively control data scheduling at the link layer and find a high data rate path with minimum interference at the network layer. We analyze the optimal capacity of the wireless mesh networks for maximizing network utilization using a numerical solution tool. Through analysis, we also verify that our algorithms can improve system capacity by efficiently distributing a gateway load and that it can enhance the system availability.

Network stability is a key performance metric in supporting real time communication over wireless networks. Because of high bandwidth demand and dynamic traffic variation, several paths in Wireless Mesh Networks (WMNs) are expected to be unstable. High levels of network instability can lead to interferences, packet losses and high delays. In this paper, we address the stability problem of WMNs. Instability in these networks is caused mainly by link quality fluctuations and frequent route flapping. First, we present the key factors that may cause network instability. Then, we propose a new technique, called Node Stability-based Routing (NSR), using the entropy function to define a node stability and a probability function to select an appropriate gateway. Simulation results show that NSR can significantly improve the overall network performance compared to techniques using interference and channel switching (MIC), Expected Transmission count (ETX) or load at gateways as a routing metric, Reinforcement learning-based best path to best gateway (RLBDR), and nearest gateway (i.e., shortest path to gateway).

Sensor network protocol stacks require the addition or adjustment of functions based on customer requirements. Sensor network protocols that require low delay and low packet error rate (PER), such as wireless control networks, often adopt time division multiple access (TDMA). However, it is difficult to add or adjust functions in protocol stacks that use TDMA methods. Therefore, to add or adjust functions easily, we propose NES-SOURCE, a compact wireless control network protocol with a fast path-switching function. NES-SOURCE is implemented using carrier sense multiple access/collision avoidance (CSMA/CA) rather than TDMA. Wireless control networks that use TDMA prevent communication failure by duplicating the communication path. If CSMA/CA networks use duplicate paths, collisions occur frequently, and communication will fail. NES-SOURCE switches paths quickly when communication fails, which reduces the effect of communication failures. Since NES-SOURCE is implemented using CSMA/CA rather than TDMA, the implementation scale is less than one-half that of existing network stacks. Furthermore, since NES-SOURCE’s code complexity is low, functions can be added or adjusted easily and quickly. Communication failures occur owing to changes in the communication environment and collisions. Experimental results demonstrate that the proposed NES-SOURCE’s path-switching function reduces the amount of communication failures when the communication environment changes owing to human movement and others. Furthermore, we clarify the relationships among the probability of a changing communication environment, the collision occurrence rate, and the PER of NES-SOURCE.

Cognitive Radio Wireless Mesh Networks (CRWMNs) are reliable and promising technology to access opportunistically spectrum holes from the licensed bands with intelligible Software Defined Radio. Multi-radio and multichannel CRWMNs are dynamic networks, which creates routing protocol design as a complex. It has a capability of assessing the spectrum availability during routing, which enhance the efficiency of the network. The proposed algorithm is a novel multipath algorithm. The path selected in this algorithm based the minimal interference information, which is useful to make this routing approach as more reliable. Channel selection has the capability to identify more suitable links for data transmission in the network. The proposed algorithm has simulated in network simulator (ns2). The simulation results demonstrate the efficiency of proposed channel selection and path aware routing algorithm.

Mobile Ad-hoc Network (MANET) is a temporarily wireless network constructed by a set of mobile devices which are communicated over wireless channel without having any fixed infrastructure and centralized administration. Multicasting is a mechanism to send a data packet from one node to a group of receivers node at a time. There are various challenges in a MANET due to dynamic network topology and limited resources. Since the network performance metrics such as delay, bandwidth and energy changes very frequently due to node mobility i.e. these network metrics have the uncertainty issues in a wireless mobile ad-hoc network. The impact of these uncertainty issues creates a problem in the selection of optimal path from source node to a group of receiver nodes. So, in this paper, we have tried to control these uncertainties issues in order to conserve the network resources using fuzzy logic tool. In this mechanism all the available network metrics of the routes is converted into a single metric i.e. fuzzy cost or communication cost. The routes having minimum fuzzy cost will be considered as optimal path and the data is to be transmitted over this path from source node to a set of receivers. The simulation has been conducted using NS-2 and MATLAB, the results shows the effectiveness of the proposed protocol (EFMMRP) over ODMRP and MAODV in terms of pacaket delivery ratio, packet delivery delay and control overhead.

In this letter, we propose a distributed network formation solution for network coding deployed wireless networks which includes multisource multicast flows. This is an attempt to solve an open problem of network coding based multisource multicast flow design based on a game theoretic approach, which can eventually form a network in a distributed way. The network is in particular constructed by individual decision makings of the nodes, while taking advantages of network coding techniques. The decisions made by the nodes include the transmission powers and the use of network coding operations. In each stage game, nodes update the parameters based on feedbacks such as rewards, penalties, and evaluate their prior actions, which enables the nodes to make best responses in the next stage game. Our simulations confirm that the resulting network can reduce overall power consumption compared to direct transmission, and improve system throughput with less power consumption compared to no coding strategy.

In this paper, we design a protocol to communicate data reliably in harsh environments. Robust data transmission with high accuracy is imperative in industrial wireless networks. The communication over a radio link in such environment gets affected by noisy surroundings. In order to maintain the high quality of services in these networks, cooperation and adaptability at a cross layer are introduced in proposed scheme. The collaborative coding used in proposed protocol; combine the data packets of network sources to improve channel capacity. This reduces the routing overheads and enhances the network gains along with the introduction of minimum delay. The performance of the network is evaluated using parameters such as throughput, reliability, channel utilization, energy, and latency for different network sizes. Results of the proposed protocol are observed and compared with the industrial wireless communication standard Wireless HART (WHART). In rest of the paper, the proposed ‘Cross Layer Cooperative Industrial Protocol’ will be termed as “XLCI Protocol”. Results shows that XLCI protocol improves the network throughput by 53%, reliability by 40%, channel capacity by 40%, also energy consumption is reduced by 70% and latency is improved by 46%, as compared to WHART.

To implement WMN, IEEE 802.11s has been developed. The routing protocol for selecting a path between two mesh stations in IEEE 802.11s is hybrid wireless mesh protocol (HWMP). But mobility of external stations has not been considered in IEEE 802.11s. For handling movement of clients, many mobility management schemes have been proposed. Some of such schemes are: ANT, Mesh Mobility Management (M $$^{3})$$ , Infrastructure Mesh (iMesh), SMesh, MEsh networks with MObility management (MEMO), Wireless mesh Mobility Management (WMM), Static Anchor Scheme, Dynamic Anchor Scheme, LMMesh, Session-to-Mobility-Ratio based Scheme and Forward Pointer-Based Mobility Management Scheme (FPBR). But none of the schemes except FPBR have been integrated with IEEE 802.11s for providing mobility support to the external stations. FPBR has been proposed to enhance IEEE 802.11s for providing mobility support to external stations, but it can support internet traffic only. In WMN both internet and intranet traffic to and from the external station is important. In this paper, an improved version of FPBR named Enhanced FPBR (EFPBR) Scheme has been introduced to handle both internet and intranet traffic. Both EFPBR and HWMP have been numerically analyzed. HWMP and EFPBR schemes are simulated and the performances are compared. From the performance comparison, it can be observed that EFPBR performs better than that of IEEE 802.11s concerning throughput, end-to-end delay, routing overhead and average handoff cost. The number of route management packets transferred per handoff measured from numerical analysis and simulation has also been compared.

Energy consumption has been a critical factor for mobile video applications. The quality of content delivery over wireless mesh networks consisting of such devices is also considered important. Existing energy-aware research and industrial effort focuses on reducing high-energy-consuming working periods of mesh devices at the expense of decreasing the quality of video content. This paper proposes AOC-MAC, an energy-quality-balanced solution, deployed at the medium access control (MAC) layer, which works in conjunction with an energy-aware routing algorithm for wireless mesh devices. The simulation and perceptual test results are also presented to investigate the performance of the proposed solution. In particular, the impacts of content delivery data rate, mesh network topology scale, and mesh device mobility are studied. Results demonstrate that AOC-MAC obtains up to 23% energy savings at roughly the same content delivery quality level in comparison with the IEEE 802.11s MAC protocol.

Efficient and reliable routing protocol is one of the key technologies in wireless sensor networks, and it has been concerned by a lot of researchers. In light of the random selection of cluster head in low energy adaptive clustering hierarchy protocol algorithm, the residual energy of nodes, node location and node density are not considered. Through theoretical deduction and mathematical calculation, the study found that it is a NP - hard problem. A swarm intelligence algorithm was introduced into the clustering algorithm of wireless sensor network, and an efficient and reliable clustering algorithm for wireless sensor networks (WSNs) based on quantum artificial bee colony algorithm was proposed. Considering the residual energy of nodes, node location and node density, and the energy consumption of the network is balanced. Experiments show that the proposed routing protocol outperforms other work in most cases by reducing the network energy consumption for WSNs by more than 13%, which indicates the feasibility of the authors' approach for efficient and reliable routing protocol in wireless sensor networks.

The Wireless Mesh Network (WMN) is a multi-hop wireless network consisting of mesh routers and clients, where the mesh routers have minimal mobility and form the backbone. The WMN is primarily designed to access outer network to mesh clients through backhaul gateways. As traffic converges on the gateways, traffic hotspots are likely to form in the neighborhood of the gateways. In this paper, we propose Congestion Aware Multi-path Routing (CAMR) protocol to tackle this problem. Upon congestion, CAMR divides the clients under a mesh STA into two groups and returns a different path for each group. The CAMR protocol triggers multi-path routing in such a manner that the packet reordering problem is avoided. Through simulations, we show that CAMR improves the performance of the WMN in terms of throughput, delay and packet drop ratio.

Maximizing network lifetime is a major objective for designing and deploying a wireless sensor network. Clustering sensor nodes is an effective topology control approach helping achieve this goal. In this paper, we present a new method to prolong the network lifetime based on the improved particle swarm optimization algorithm, which is an optimization method designed to select target nodes. The protocol takes into account both energy efficiency and transmission distance, and relay nodes are used to alleviate the excessive power consumption of the cluster heads. The proposed protocol results in better distributed sensors and a well-balanced clustering system enhancing the network's lifetime. We compare the proposed protocol with comparative protocols by varying a number of parameters, e.g., the number of nodes, the network area size, and the position of the base station. Simulation results show that the proposed protocol performs well against other comparative protocols in various scenarios.

In this letter, we address the following problem: given a mesh network deployment and $|\mathbb{G}|$ gateways to be added, what is the optimal gateway placement with the constraint of energy-minimization for green wireless mesh networks. Unlike previous research, which focuses on throughput optimization, we contribute by developing a mixed-integer linear programming (MILP) formulation, which satisfies the given flow demands while minimizing the global energy consumption of the network. The proposed solution is NP-hard; therefore, we also propose a heuristic-based greedy algorithm to efficiently solve large instances of this problem. To capture interference in the mesh network, we use the physical-interference model but employ a greedy algorithm to reduce the computation time for finding maximal independent sets. We implement both the MILP formulation and the greedy solution along with three other contemporary solutions in the area. Numerical results show that the proposed exact scheme provides the optimal result, while the greedy solution provides a solution within 5% of the optimal solution with just 1% computation time for green wireless mesh networks.

In recent times, Wireless Mesh Network (WMN) has received prominence worldwide due to the evolution of wireless networks as a ubiquitous and seamless broadband service provider. Routing on WMNs is one of the most prominent research issues on these days. Hierarchical clustering based routing protocols are proposed by the researchers for large networks. In these protocols, all the available nodes are grouped into clusters. Each clus-ter consists of cluster members, cluster head and gateway nodes where cluster head plays the most vital role to form an efficient cluster. Selection of a better cluster head depends on the decisions made from different parameters and their relations. In this situation, fuzzy logic suits better by providing better analysis and helps to make the right decision based on different parameter values and their relations. In this paper, a fuzzy logic based hierarchical clustering technique is proposed for WMN. The proposed technique along with the existing Fuzzy Logic Control Clustering Algorithm(FLCCA) are experimented using the simulation software NS3 and the simulated results are compared to establish the efficiency of the proposed technique.

Multicasting is an efficient data transmission approach for group communication applications in multi-channel multi-radio wireless mesh networks. In this paper we have studied the problem of accepting on-line multicast requests, which is quite important for supporting multimedia applications. Our proposed algorithm investigates the acceptance of an arrived call in two phases. In the first phase, a loop-free mesh backbone is constructed. In this mesh, the set of possible parents of each node is limited to the neighbors that are one hop closer to the source node. The neighbors with the same distance from the source node are also acceptable under the circumstance that two neighboring nodes cannot be the possible parents of each other. Next, a sub-optimal mathematical model has been proposed for tree construction over the obtained mesh. The derived multicast trees utilize the minimum amount of bandwidth; are load-balanced; and exploit wireless broadcast advantage. The results show that the proposed algorithm improves the rate of multicast call acceptance by 40% on average compared to previous algorithms in a short running time.

In wireless mesh networks (WMNs), mesh clients communicate with each other via the gateway and bridging functions of mesh routers. The performance of a WMN is generally affected by its network connectivity and client coverage, both of which are determined by its router node placement (RNP) in the deployment area. For simplicity, previous works considered only the RNP where each mesh client is served as an equal. In practice, however, mesh clients should be served with different priorities owing to factors such as their importance and their different payments for the service access. To fulfil this requirement, by assuming that each mesh client is also associated with a service priority, this paper investigates an RNP problem with a service priority constraint in which the mesh clients with service priorities higher than a threshold must be served. Given that this problem inherited from the complexity of the original RNP problem is computationally intractable in general, this paper also develops a novel simulated annealing (SA) approach that takes into account momentum terms to improve the efficiency and accuracy of annealing schedules and prevent fluctuations in values of the acceptance probability function. Additionally, the time complexity of the proposed SA algorithm is analyzed. Furthermore, evaluation of different-size instances under various parameters and annealing schedules demonstrates the superiority of the proposed approach.

Wireless Mesh Networks offer an effective technology to establish broadband wireless services. Due to this application, robustness against failures and throughput improvement are the two main objectives in designing such networks. In this paper, we use the "topology control" as a set of tools to reach these objectives. Topology control in wireless mesh networks is an NP-hard problem; therefore, we propose a heuristic method known as Fault-Tolerant Interference-Aware Topology Control (FITC) to solve it in a distributed fashion. In this method, we first guarantee that the network is K-Connected using the graph modification, routing and channel assignment. Then, power control, rate adaptation, channel selection and scheduling is applied to enhance the network throughput. Due to the static channel assignment and the fixed location of the nodes in the network, the first part of the algorithm is conducted using a centralized method, while a distributed cross layer method is applied for the second part. Simulation results validate the efficiency of the proposed method in achieving the main objectives.

Wireless Mesh Sensor nodes are deployed in harsh environments, like Industrial Wireless Mesh Sensor Networks (IWMSN). There the equipment is exposed to temperature and electrical noise, so providingareliable, interference free and efficient communication in this environment isachallenge. We proposea Multi Route Rank based Routing (MR3) protocol, which enhances the link dynamics for IWMSNand also provides interference free reliable packet delivery in harsh environments. The rank ofanode is estimated based on density, hop count, energy and Signal to Interference plus Noise Ratio (SINR). The route discovery phase finds the rank value to forward the data packet inareliable path. Once the forwarding path is established, subsequently the data packets can be propagated towards the destination without using any location information. Our simulation results show that this method improves the packet delivery ratio and the throughput tremendously, and at the same time minimizes the packet delay, in heavy traffic condition.

Conventionally, router node placement is concerned with placing only routers to serve clients; and gateway placement is concerned with placing only gateways to achieve some requirements for routers. More generally, this work considers the placement with routers and gateways simultaneously, while clients can move based on their own willingness. That is, this work investigates the adaptive placement problem of a dynamic wireless mesh network (dynWMN) consisting of mesh clients, mesh routers, and Internet gateways. Given fixed positions of Internet gateways, this problem is to adjust positions of mesh routers dynamically to make each mesh client connected with some gateway via multi-hop communication at different times, when each mesh client may switch on or off network access, so that both network connectivity and client coverage are maximized, subject to the Quality of Service (QoS) constraints of delay hops, relay load, and gateway capacity. To avoid almost-overlapping routers and few-clients-covered routers in router node placement, this work further proposes a novel particle swarm optimization approach with three local search operators. In simulation of dynWMNs, dynamics of mesh clients can be characterized by a Markov chain, and hence, their stable states can be derived theoretically and are used as criteria of evaluating performance, by which the proposed approach shows promising performance and adaptability to topology changes at different times.

As the growth of mobile data traffic places significant strain on cellular networks, plans for exploiting under-utilized network resources become increasingly attractive. In this paper, we propose, design, and evaluate a data offloading architecture, where mobile users are offloaded to mesh networks, which are built and managed by residential users. Such networks are often developed in the context of community networks or, recently, as commercial services. Mobile network operators can lease capacity from these networks and offload traffic to reduce their servicing costs. We introduce an analytical framework that determines the offloading policy, i.e., which mobile users should be offloaded, based on the energy cost induced to the cellular base stations. Accordingly, we design a minimum-cost servicing policy for the mesh networks. Clearly, such architectures are realizable only if the mesh nodes agree with each other to jointly serve the offloaded traffic. To achieve this, we employ the Shapley value rule for dispensing the leasing payment among the mesh nodes. We evaluate this paper by simulating the operation of the LTE-A network, and conducting test bed experiments for the mesh network. The results reveal significant savings for eNBs power consumption and reimbursements for mesh users.

The Channel Assignment (CA) is an efficient tool to exploit multiple non-overlapping channels to minimize interference and enhance the capacity of the wireless mesh network. Even though the CA can minimize the total network interference, its result may cause some design issues which influence the network performance. First, the CA alters the network topology which in turn may produce unconnected logical topology. Second, the interaction between the CA and routing protocol where the effective capacity of each link depends on the routing decision and the result of CA. In this article we focus on multi-radio, multi-channel wireless mesh network. First, we defined the channel assignment (CA) design issues. Second, we classified the CA approaches based on the main design issues. For each CA approach, its advantages and limitations are highlighted. Third, the overall comparison for the classification is given in details. Finally, we discussed the future research direction for channel assignment.

Wireless Sensors Networks (WSN) have gained a lot of significance because of potential applications such as Marine engineering, Human body tissue study and animal life study. The scope of WSN is limited to some extent due to tiny battery inside the node, thus limiting the scope of applicability where replacing a battery is infeasible. A research to solve this issue has been proposed in this paper. The motivation behind this work is the LEACH protocol which is considered as the oldest technique for Energy Conservation in WSN. But with the advancement in the fabrication of nodes, this protocol needs to be altered to cater the needs. Analysis proved that Intelligent LEACH (I-LEACH) is better than MOD-LEACH approach (A variation to LEACH) in terms of increased lifetime. Results depict 54% increase in the lifetime of the network as compared to MOD-LEACH, which ensures longer connectivity and reliability.

Opportunistic routing (OR) is a promising paradigm that has been proposed for wireless mesh networks. This routing paradigm takes advantage of the broadcast nature of the wireless medium to increase the reliability of transmissions in multihop wireless networks. The selection of a set of candidates involves satisfying the basic requirements of the model, in which packets are forwarded toward the destination. In OR, if one of the selected candidates does not receive the packet, another candidate might be able to continue forwarding the packet. The decision of which forwarder to choose is made by coordination between candidates that have successfully received the transmitted packet. In this paper, we propose a discrete-time Markov chain as a general model for OR and demonstrate how it can be used to evaluate the performance of OR protocols. We also review three well-known OR protocols that we have selected as a study case. Our study demonstrates how our model facilitates better understanding of the combination of a number of candidates and retransmissions and their significant contributions to the successful delivery of data packets. Thus, this shows that our model can help in the design of future OR protocols and efficient candidate selection algorithms.