Throughput Optimization Routing Under Uncertain Demand for Wireless Mesh Networks

Routing is a critical component in wireless mesh networks. The inherent shared-medium nature of the wireless mesh networks, however, poses fundamental challenges to the design of effective routing policies that are optimal with respect to the resource utilization. Node churns and traffic fluctuations exacerbate such a problem. In this paper, we propose a novel adaptive routing algorithm for multiple subscribers in wireless mesh networks. We view a mesh network with multiple nodes as an entity that optimizes some global utility function constrained by the underlying MAC layer interference. By solving the optimization problem, the network is driven to an efficient operating point with a certain routing policies for each node. We then use this operating point information to adaptively find better paths, which is able to gear the network towards optimal routing. Further, we take the fluctuations of the network into consideration and thus render our algorithm more robust for a variety of network situations. Simulations demonstrate the efficiency and efficacy of our algorithm.

Field Based Routing (FBR) is the next promising class of routing algorithms especially for wireless mesh networks. The inherent nature of shared medium wireless mesh networks, however, poses fundamental challenges to the design of effective routing policies that are optimal with respect to speed, time and resource utilization. In this paper, globally optimized routing algorithm for multiple subscribers in wireless mesh networks is proposed. Mesh network with multiple nodes will serve as an environment that optimizes some global utility function limited by the mobile nodes position in underlying MAC (Media Access Control) layer. By solving the optimization problem, the network is brought to a point of efficient operation with a certain routing policy for each node. This information will be the operating point that can be used to find better ways adaptive, which is able to steer the network towards the optimal routing. Global optimization of FBR is depicted through path estimation using PSO (Particle Swarm Optimization).

Wireless technology has become an essential part of this era’s human life and has the capability of connecting virtually to any place within the universe. A mesh network is a self healing wireless network, built through a number of distributed and redundant nodes to support variety of applications and provide reliability. Similarly, anycasting is an important service that might be used for a variety of applications. In this paper we have studied anycast routing in the wireless mesh networks and the anycast traffic from the gateway to the mesh network having multiple anycast groups. We have also studied the geocast traffic in which the packets reach to the group head via unicast traffic and then are broadcasted inside the group. Moreover, we have studied the intergroup communication between different anycast groups. The review of the related literature shows that no one has considered anycasting and geocasting from gateway to the mesh network while considering the multiple anycast groups and intergroup communication. The network is modeled, simulated and analyzed for its various parameters using OMNET++ simulator.

Wireless Mesh Networks offer a high-performance and low-cost solution to last-mile broadband Internet access. Routing and Scheduling play a critical role in determining the performance of a wireless mesh network. Efficiency of Routing and Scheduling algorithms is highly dependent on the availability of accurate traffic information. In this paper, we predict network traffic based on past data using ARIMA model, and provide that input to the routing and scheduling algorithm. Joint routing and scheduling results in significant performance improvement over the routing only algorithms. So, we provide predicted network traffic information to a Joint routing and scheduling algorithm known as Traffic Oblivious Routing and Scheduling. Traffic Oblivious Routing and Scheduling algorithm optimizes the worst case performance under traffic uncertainty but when accurate traffic information is available to the algorithm, its performance is enhanced. In the Traffic Oblivious Routing and Scheduling algorithm, computing the routing and the scheduling values is a one time overhead. In this paper, we present a system where we predict network traffic information using past data, then use the predicted information to formulate the input for the Traffic Oblivious routing and scheduling algorithm and finally we evaluate the performance of the algorithm using simulations.

Interference makes it difficult for a wireless network to provide robust performance and could sometimes lead to transient failures. Dynamic channel switching (DCS) allows a wireless network interface (NIC) to operate in different frequency channels during different time periods without disrupting network connections that traverse the NIC. DCS enables a wireless mesh network to avoid frequency channels with serious interference in certain parts of its coverage area by switching to more idle channels. Although DCS provides additional radio agility, it significantly increases the complexity of the wireless mesh network's routing protocol. This paper describes the design, implementation and evaluation of a wireless mesh network system called Carlsbad, which supports both DCS and load-balancing/fault-tolerant routing, and successfully runs on low-cost commodity IEEE 802.11-based access points. Performance experiments on the first Carlsbad prototype show that despite the additional overhead it introduces, DCS can indeed improve the overall throughput of an IEEE 802.11-based wireless mesh network, sometimes by a factor of more than 2, for both TCP and UDP connections.

Wireless technology is emerging as a key technology for the future networks. Wireless mesh networks (WMNs) have emerged as an indispensable technology for deployment of wireless services for various applications in personal, enterprise, and metropolitan areas. Researchers are working actively in different fields of WMNs for providing better services. Routing protocols play a vital role in WMNs to provide reliable configuration and maintenance of topology of the network. Designing a suitable cost metric for routing protocols to provide quality links for data transmission is the backbone of WMNs. Many cost metrics have been proposed for WMNs and is still an active research topic as new performance metrics need to be discovered due to the dynamics of this field. This paper considers the genetic algorithm-based routing technique for WMN.We have studied the existing cost metrics and proposed a genetic algorithm technique for routing in WMN. To evaluate the genetic algorithm, and to determine the relative performance of the genetic algorithm in the context of routing in WMN, we carry out experiments on two test systems. We have evaluated the quality of the results produced by our algorithm with the traditional hop count metric results. Our results show that routing in WMN using genetic algorithm produces better results as compared to traditional hop count metric results. Finally, we carry out a detailed analysis of results, which help us in gaining an insight into the suitability of genetic algorithm for routing in WMN.

Wireless mesh network (WMN) is a peculiar type of growing technology that can alter the world more effectively in the coming decades. Multicast routing in mesh networks is the distribution of data from a single source to multiple destinations or multiple sources to multiple destinations through the intermediate nodes. There can be many numbers of intermediate nodes between source and destination. But the number of hops a packet traverses decides the energy consumed, data rate, speed, throughput and other characteristics of a network. The reduction in the number of hops leads to reduced processing of data which leads to reduced consumption of power. In this paper, energy coherence for wireless mesh networks from a point of view that started recently to attract the attention of the conservation of energy for operational and the environment reasons which is known as the Green Networking is considered. This paper discusses the energy coherence of multicast routing algorithm based on angle which reduces the hop count leading to reduction in energy consumption and the angle with efficient energy optimization is found. Not only the energy, other network parameters like throughput, delay, packet delivery ratio, packet loss ratio have also been improved at the appropriate angle. This in turn enhances the QoS of the network.

The problem of scheduling and tree routing in WiMAX/802.16 based mesh networks were not defined in the standard and are thus subject to extensive research. In this paper, we consider the problem of joint routing and scheduling in 802.16-based wireless mesh network, with the objective of determining a minimum length schedule that satisfies a given (uplink/downlink) end-to-end traffic demand. Minimizing the schedule length amounts to maximizing the spectrum spatial reuse by concurrently transmitting on as many links as possible, which we refer to as a transmission configuration (a group of links that can simultaneously transmit without violating the signal-to-interferenceplus- noise ratio (SINR) requirement). Our model is referred to as maximum spatial reuse (MSR). Since there is an overwhelming number of possible transmission configurations to be assigned to time slots, we adopt the column generation technique to construct our MSR model. We present two formulations for modeling MSR, namely the link-based column generation (CGLink) formulation and the path-based column generation (CGPath) formulation. These two formulations differ mainly in the number of routing decision variables. Our experimental results indicate that the path-based formulation needs much less computational (CPU) time than the link-based formulation in order to determine the (same) optimized solution with the same spatial reuse gain.

QoS routing in wireless mesh networks (WMNs) is a daunting task. Finding a path for a given flow depends not only on the bandwidth-delay requirements of that flow but also on the available bandwidth of all the nodes in that path and the amount of bandwidth consumption caused by that flow along its path. Contrary to the wired networks, these two parameters are not fixed and depend on the interference pattern of the network that in turn depends on the selected path itself. This converts the QoS routing in wireless mesh networks to a much harder problem. Existing methods use on-demand approach based on flooding of routing packets. This approach does not scale up to large networks. Field-based routing (FBR) is a promising approach to reduce the routing overhead for static route set up. However, it is not previously used for QoS routing. In this paper, we have developed a new FBR based QoS routing protocol for WMNs. Contribution of this paper is two folds. First, a one-pass field-based routing instead of regular two-pass approach is developed that significantly reduces the overhead of distributing routing information and computing the path and increases the QoS delivered to the flows. Secondly, a new routing metric named LU-IR is introduced that is shown to lower intra-flow and inter-flow interferences and results in increased network service capacity. The performance of the proposed algorithm is extensively studied through simulations. The results indicate that average delay of the flows is improved and the network throughput is increased compared to the existing schemes.

This paper proposes a new hybrid, optimal cost based routing approach namely HGAB3C implemented for routing in wireless mesh networks (WMNs). We used this proactive routing approach to find the optimal paths in dynamically created WMN of client nodes. The performance of proposed approach was evaluated with different architectural scenarios from 1000 nodes to 10,000 nodes WMNs with a step increase of 1000 nodes. The route costs were evaluated using integrated link cost (ILC) measure which is a function of jitter, network delay and throughput. Performance of this proposed approach was compared with seven other soft computing based approaches and two hard computing based algorithms. The proposed approach outperformed all the other 9 competing approaches. The proposed algorithm can also be used effectively in isolation wards of COVID-19 hospitals and quarantine centers where robots can be networked for communications between patients and doctors.

Finding the shortest route in wireless mesh networks is an important aspect. Many techniques are used to solve this problem like dynamic programming, evolutionary algorithms, weighted-sum techniques, and others. In this paper, we use dynamic programming techniques to find the shortest path in wireless mesh networks due to their generality, reduction of complexity and facilitation of numerical computation, simplicity in incorporating constraints, and their onformity to the stochastic nature of some problems. The routing problem is a multi-objective optimization problem with some constraints such as path capacity and end-to-end delay. Single-constraint routing problems and solutions using Dijkstra, Bellman-Ford, and Floyd-Warshall algorithms are proposed in this work with a discussion on the difference between them. These algorithms find the shortest route through finding the optimal rate between two nodes in the wireless networks but with bounded end-to-end delay. The Dijkstra-based algorithm is especially favorable in terms of processing time. We also present a comparison between our proposed single-constraint Dijkstra-based routing algorithm and the mesh routing algorithm (MRA) existing in the literature to clarify the merits of the former.

Nowadays there are inexpensive WiFi devices that have fostered the deployment of wireless communities. Well known routing protocols used in the Internet do not fit well to time varying characteristic of wireless networks. This has motivated an intensive research on routing protocols for wireless mesh networks. At this time there are a number of mature and stable implementations that are being deployed in production networks. In this paper we focus on the experimental evaluation of a production Wireless Mesh network being deployed in a testbed at Universitat Politecnica de Catalunya (UPC) and a quarter of the city of Barcelona, Spain. To our best knowledge, this is the first paper where a production community wireless network using 802.11an is analyzed.

The ultimate goal of routing in wireless mesh networks (WMNs) is to find the “good” paths between the source and destination. Considering of the characteristics of this new networking paradigm, such as low mobility and less restriction from the energy effect, the focus is on the design and optimization of the technology to establish the path that can reflect this network feature. In this paper, an efficient routing algorithm is proposed based on decision-making sequence in WMNs, and the routing process is mapped into multi-stage decision process. We construct a mathematical model for it and present a multi-decision sequential routing method taking use of the idea of dynamic programming. In addition, a new metric (EEDT) for routing based on the information of MAC layer in WMNs is given, which optimized the two objectives- end to end delay and throughput. In the end, the multi-decision sequential routing algorithm (MDSR) is proposed that synthesized the suggesting method and new metric. The path selected by MDSR would be better based on the mathematical model, and it has lower delay of routing building. At the same time, EEDT can accurately capture the quality of the network links. Simulation results show that the proposed routing algorithm significantly improves the performance of the WMNs in terms of end-to-end delay and throughput.

Multi-hop Wireless Mesh Networks (WMNs) is a promising new technique for communication with routing protocol designs being critical to the effective and efficient of these WMNs. A common approach for routing traffic in these networks is to select a minimal distance from the source to destination as in wireless networks. Opportunistic Routing (OR) makes use of the broadcasting ability of wireless network and is especially very helpful for WMN because all nodes are static. Our proposed scheme of Multicast Opportunistic Routing (MOR) in WMNs is based on the broadcast transmissions and Learning Automata (LA) to expand the potential candidate nodes that can aid in the process of retransmission of the data. The receivers are required to be in sync with one another in order to avoid duplicated broadcasting of data which is generally achieved by formulating the forwarding candidates according to some LA based metric. The most helpful aspect of this protocol is that it intelligently learns from the past experience and improves its performance. The results obtained via this approach of MOR show that the proposed scheme outperforms some existing schemes and is an improved and more effective version of opportunistic routing in a mesh network.

Efficient multicasting over Wireless Mesh Network (WMN) is challenging due to dynamic and multi-hop wireless communication among multicast group members. Multicast Ad hoc On-Demand Distance Vector (MAODV) protocol is a tree based multicast routing protocol that enables dynamic, self-starting, multi-hop routing between participating mobile nodes wishing to join or participate in a multicast group in Wireless Mesh Network (WMN). The mobility of mobile nodes often causes link breakage in the tree-based protocols which sometime results in tree partitioning and poor performance. In MAODV, when a broken link is detected between two nodes on the multicast tree, the node downstream to the break is responsible for initiating the repair of the broken link. After link repair, it is likely that the previous distance between the nodes (nodes downstream to the link breakage) and the group leader will not remain same. The shortest path from the group leader to the nodes downstream to the node which initiates link breakage is not ensured. Moreover, if the node attempting to repair a tree link break does not receive a response after certain attempts, it assumes that the multicast tree is not repairable currently and this leads to tree partitioning. In this paper, an improved link repair technique is proposed which ensures shortest path from any node to the group leader. Simulation results demonstrate significant improvement in performance metrics compared to standard MAODV.