Download or read book Deployment and Performance Enhancement of Wireless Mesh Networks written by Daniel Wu and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless mesh networks provide necessary network connectivity in rural and remote locations through multi-hopping. To avoid contention and congestion in the wireless channel and degradation in overall performance, a mesh network must be optimized. This dissertation proposes characterization studies in deployment and performance enhancements of wireless mesh networks. Characterizations in wireless mesh network deployments enable network planners to optimize network equipment usage more efficiently. Studies in performance enhancement techniques also enable researchers to create more efficient algorithms. This dissertation illustrates the deployment and performance enhancements characterizations in three phases. The first phase is a large-scale wireless mesh network deployment in a natural reserve. The QuRiNet deployment provides a testing ground for developing new wireless optimization protocols and acts as a backbone network for remote ecological and network data collection. The second phase is a study of wireless link quality in a network. A well-developed wireless link quality characterization study gives insights into the behavior of a wireless network. The final phase uses the link quality study and the multi-radio multi-channel features of QuRiNet for optimization. Specialized static channel assignment algorithms are evaluated to yield a near-optimal network topology. We compare integer linear programming solutions along with breadth-first search and priority-based selection heuristics to determine which algorithm is suitable for QuRiNet.

Download or read book Performance Enhancement of Wireless Mesh Networks written by Noun Choi and published by . This book was released on 2008 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: With advances in wireless technologies, broadband wireless networks have been increasingly demanded recently. Several approaches are actively discussed in order to provide broadband network access to the mobile users. IEEE 802.16 based WiMAX has been proposed to provide long distance wireless data communication. Cellular network industry is also moving toward the next generation network system which is the fully IP based network.

Download or read book Wireless Network Performance Enhancement via Directional Antennas Models Protocols and Systems written by John D. Matyjas and published by CRC Press. This book was released on 2015-11-18 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: Directional antenna technologies have made significant advancements in the last decade. These advances have opened the door to many exciting new design opportunities for wireless networks to enhance quality of service (QoS), performance, and network capacity. In this book, experts from around the world present the latest research and development in

Download or read book Performance Improvement for Wireless Mesh Networks with Renewable Energy Source written by Peng Sun and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Multi-radio multi-channel wireless mesh networks (WMNs) have been the focus of numerous research efforts during the past few years. These efforts aimed at extending the utilization of technologies based on the IEEE 802.11 standard in large-scale communities and even for city wide networking. However, mesh nodes in these networks are typically limited in their resources (e.g., bandwidth, power and radio interfaces). Such a limitation has led to an unsatisfactory network performance as well as users dissatisfaction. This dissertation addresses three important performance issues related to WMNs, namely, network performance enhancement, network survivability and green communications. To address the first issue, a novel quality of service (QoS) aware joint channel assignment (CA) and routing algorithm is developed. The proposed algorithm employs both dynamic and static CA techniques and corresponding link schedules that maximize the network throughput and minimize the delay and packet loss ratio. Next, the thesis addresses the problem of network survivability and theoretically analyzes the effects of node failure probabilities on the ability of the remaining network nodes to maintain their connectivity. A tight upper bound on the node failure probabilities needed to maintain full network connectivity on the one hand is first developed. On the other hand, a lower bound, at which the system loses connectivity, is also derived. We show that these bounds are dependent only on the nodes' geometric distribution and density. Based on the premise that failure of nodes in a small area may lead to failure of dependent nodes in other areas due to the quick divergence of traffic in these areas, an efficient node failure backup scheme is presented. The scheme relies on the capacity of the surviving network components in order to find new paths that do not overload the neighbours of the failed node which reduces the probability of generating congestion. Finally, the thesis addresses the problem of realizing energy-efficient WMNs that can operate using renewable energy sources. In these systems, batteries are often used to store and regulate the use of the supplied green energy to transmit the received data at each network router in order to overcome the problem of supply fluctuating of various energy sources. To realize these networks, the behaviour of the residual energy of the battery at a heavily loaded green wireless mesh node with a general traffic arrival and energy charging functions is first analyzed. Based on obtained theoretical results, both an online and an offline QoS aware packet scheduling schemes are proposed to minimize the probability of depleting the battery. Each of the aforementioned contributions is supported with various experimental evaluations to demonstrate the achieved performance enhancements.

Download or read book Advances in Wireless Mesh Networks written by Timothy Kolaya and published by . This book was released on 2015-02-26 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The latest advances in the field of wireless mesh networks have been described in this profound book. It presents an insight into current developments related to new design techniques and algorithms to enhance performance and functionality of Wireless Mesh Networks (WMNs). Information in this book has been contributed by reputed veterans in wireless mesh networking. The book highlights link scheduling schemes for selection of a subset of links for simultaneous transitions under interference restraints in an effective and appropriate manner to guarantee a specific level of network connectivity. It also elucidates channel assignment techniques for enhancement of network throughput in multi-channel multi-radio wireless mesh networks through effective channel utilization and minimization of the interference. The book addresses a few significant network planning issues regarding effective routing protocols in dynamic large-scale mesh environment, the accuracy of the mesh security architecture, attainable capacity limit of a single wireless link between two multi-interface mesh nodes and fault-tolerant mesh network topology planning.

Download or read book Capacity Enhancement and Reliability of Wireless Mesh Networks written by Hua Yu and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless mesh networks (WMNs) have gained considerable interest in expanding IEEE 802.11 networks to large-scale enterprise and community scenarios, primarily because its capability of providing wide-band ubiquitous network access to a significant number of users. However, the mesh nodes are typically limited in resources such as bandwidth, computation power and memory. Moreover, the shared wireless medium introduces the interference. All these result in unsatisfactory network performance. In this dissertation, we tackle several issues related to the system performance of the wireless mesh networks. In the context of the network capacity enhancement, we focus on using the techniques of multi-channel multi-radio (MCMR) and partially overlapped channels (POC) respectively; In the context of network reliability, we focus on the measurement-based analysis and prediction of reliability in an experimental way. Capacity limitation is one of the fundamental issues in wireless mesh networks. We start our investigation by addressing capacity improvement enabled by multiple radios and channels with a centralized scheduling approach. In a MCMR network, our objectiveis to find both dynamic and static channel assignments and corresponding link schedules that maximize the network capacity. We focus on determining the highest gain we can achieve from increasing the number of radios and channels under certain traffic demands. When the number of orthogonal channel is few or multiple radios are not available, the use of partially overlapped channels is explored to enhance the capacity in wireless mesh networks. We investigate how the interference can be useful for communication when POC is properly utilized. We propose novel channel allocation and link scheduling algorithms in the MAC layer to enhance network performance. Due to different traffic characteristics in multi-hop WMNs compared to those in one-hop 802.11 networks, we perform our optimization based on end-to-end flow requirement, instead of the sum of link capacity. In addition, we discuss other factors affecting the performance of POC, including topology, node density, and distribution. To better understand how reliable a wireless mesh network performs, we perform a systematic experimental study to investigate the impacts of different factors on the unreliabilityof a mesh network and the sources causing such unreliability. The factors that we studied include traffic load, number of hops and flows, transmission rates, maximum retransmission limits and the RTS/CTS mechanism. Our results are based on measurements performed on our real-world mesh network testbed. In identifying the sources of packet loss, we developed a tool, FlowPaC, to collect flow-based statistics at different points in the system to understand the effects of the MAC layer parameters and the traffic attributes. We also explore the potential remedies for the system configuration and thereby improve the reliability of wireless mesh networks. Prediction of network reliability of WMNs at the level of individual flows in a small time granularity becomes very important, but is missing in the literature. Traditionally, the reliability of WMNs is measured as long-term averaged metrics, such as packet delivery ratio. However, WMNs are very dynamic in nature due to fluctuation of channel conditions and contention among multiple flows, so long-term averaged metrics cannot reflect the short-term behaviors of the network. Moreover, the users may require a sustained reliability for a certain period of time. In this dissertation, we measure reliability using metrics of both the goodput and packet loss in short intervals of time for individual flows. We propose a model to predict the short-term reliability for a user's flow in WMNs. Based on the measurement results obtained from our tools Rater and CalMedium, our model can achieve the prediction accuracy and avoid the complexity of the inter-dependency among the traffic, different system queues, interference, and MAC-induced factors. The predicted results have a good match with those obtained from our real-world mesh network testbed for both single-flow and multiple-flow scenarios. We also demonstrate two application examples of utilizing our work: finding the bottleneck rate of a flow and admission control.

Download or read book Energy efficient Throughput Enhancement in Wireless Mesh Networks Via Intelligent Channel Selection written by Asitha U. Bandaranayake and published by . This book was released on 2013 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless Mesh Networks (WMNs) have generated a lot of enthusiasm over the last decade or so, both in research and experimental implementations. However, they are yet to reach their full potential and deliver on the promise of ubiquitous high-speed Internet access due to a number of real-world limitations. As such, the current research focus is shifting towards understanding the ground realities of having high-performing WMNs and finding solutions to any associated shortcomings. Having observed the division between the theoretical possibilities and the practical realities of WMNs, our approach to bridging this gap is to get first-hand practical experience by building an indoor WMN testbed. This testbed was built with commercial off-the-shelf hardware and free open-source software, without any modifications, with the goal of looking at the problem from the users' perspective. The objective of this approach is to identify practical limitations on the performance of a WMN implemented with existing wireless technologies. The most important criterion for achieving maximum performance in a WMN is to limit the interference within the network. For this purpose, the best option is to use non-overlapping channels among different network radios within the interference range, especially in a multi-radio network. The existing research that have used non-overlapping channels as the basis for performance optimization, has assumed link quality across all the channels to be uniform. However, our observations from an extensive experimental study show that the generalized assumption of uniform performance across all the channels does not hold true in actual practice for an indoor environment. Thus, it is imperative that this knowledge is used in the configuration of a WMN to maximize the performance. The success of these attempts has the potential to propel the popularity of WMNs to a whole new level. However, with increasing popularity, energy efficiency also becomes a major consideration in WMN design, not only to facilitate power-constrained usages, but also to be proactive in energy conservation. The existing research in WMNs considers energy-efficiency as an after-thought at best, especially due to existing criteria and metrics not being designed with energy-efficiency in mind. In this dissertation, we present a new energy-aware link quality metric that could be used at the initial configuration of a WMN to increase the average throughput, while reducing the power consumption. We validate our claim with a detailed measurement study on our WMN testbed. We show that in addition to increasing the throughput and reducing the power consumption, we can also enhance the connectivity of the network by using this link quality metric. We then introduce two channel selection algorithms based on our link quality metric to be used at the initial configuration of a WMN to improve the throughput and energy consumption in WMNs. We analyze the efficacy of these algorithms by comparing its performance with networks configured with channel selection algorithms from two highly-cited works in this area. We validate our claim of using channel selection algorithms based on link quality variations to achieve better results, using an extensive series of simulations.

Download or read book Wireless Mesh Networks written by Mutamed Khatib and published by . This book was released on 2020-05-13 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Traffic Engineering Multi layer Optimization for Wireless Mesh Network Transmission written by Okechukwu Emmanuel Muogilim and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An IEEE 802 11 Based Wireless Mesh Disaster Recovery System with Lifetime Enhancement written by Christopher Hepner and published by Cuvillier Verlag. This book was released on 2019-08-28 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: After the occurrence of a disaster (e. g. an earthquake or tsunami) one of the main needs for the rescue teams and volunteer helpers is a functional communication infrastructure even during the first hours. The disaster recovery system (DRS) which is proposed in this work is based on an IEEE 802.11s wireless mesh network which is set up by non-damaged, legacy, mesh capable and battery powered devices still available in the disaster region. Key considerations concerning the performance of a DRS are the required node density, the coverage that can be achieved by a given node density, scalability as well as the lifetime of the system. For lifetime of the system. For lifetime enhancement, which is a key challenge for the proposed DRS on battery powered devices, a distributed algorithm is proposed which enhances the lifetime of such a system by an approach which allows to shut down non-necessary nodes and to keep them for a later usage while still keeping network connectivity.

Download or read book Designing for Network and Service Continuity in Wireless Mesh Networks written by Parth H. Pathak and published by Springer Science & Business Media. This book was released on 2012-11-02 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: “Designing for Network and Service Continuity in Wireless Mesh Networks” describes performance predictability of the new wireless mesh network paradigm, and describes considerations in designing networks from the perspective of survivability and service continuity metrics. The work provides design insights for network design researchers and industry professionals. It includes designs for new mesh networks and extensions of existing networks with predictable performance.

Download or read book Wireless Mesh Networking written by Yan Zhang and published by CRC Press. This book was released on 2006-12-13 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt: A promising new technology, wireless mesh networks are playing an increasingly important role in the future generations of wireless mobile networks. Characterized by dynamic self-organization, self-configuration, and self-healing to enable quick deployment, easy maintenance, low cost, high scalability, and reliable services, this technology is beco

Download or read book Directional Antennas in Static Wireless Mesh Networks written by Francisco Fernandes and published by LAP Lambert Academic Publishing. This book was released on 2014-05-31 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: Previous research done in wireless mesh networks, typically assumes omni-directional antennas are used, which has the implication of when two nodes are communicating, all nodes in the vicinity must stay silent. With the use of directional antennas, two nodes can communicate without affecting communications of other nodes in the vicinity. One of the primary objectives of this book is to exploit these opportunities that directional antennas can provide, and translate that into improvements of the performance of the mesh network.

Download or read book Contribution to the Improvement of the Performance of Wireless Mesh Networks Providing Real Time Services written by Andrés Marcelo Vázquez Rodas and published by . This book was released on 2015 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nowadays, people expectations for ubiquitous connectivity is continuously growing. Cities are now moving towards the smart city paradigm. Electricity companies aims to become part of smart grids. Internet is no longer exclusive for humans, we now assume the Internet of everything. We consider that Wireless Mesh Networks (WMNs) have a set of valuable features that will make it an important part of such environments. WMNs can also be use in less favored areas thanks to their low-cost deployment. This is socially relevant since it facilitates the digital divide reduction and could help to improve the population quality of life. Research and industry have been working these years in open or proprietary mesh solutions. Standardization efforts and real deployments establish a solid starting point.We expect that WMNs will be a supporting part for an unlimited number of new applications from a variety of fields: community networking, intelligent transportation systems, health systems, public safety, disaster management, advanced metering, etc. For all these cases, the growing needs of users for real-time and multimedia information is currently evident. On this basis, this thesis proposes a set of contributions to improve the performance of an application service of such type and to promote the better use of two critical resources (memory and energy) of WMNs.For the offered service, this work focuses on a Video on Demand (VoD) system. One of the requirements of this system is the high capacity support. This is mainly achieved by distributing the video contents among various distribution points which in turn consist of several video servers. Each client request that arrives to such video server cluster must be handled by a specific server in a way that the load is balanced. For such task, this thesis proposes a mechanism to appropriately select a specific video server such that the transfer time at the cluster could be minimized.On the other hand, mesh routers that creates the mesh backbone are equipped with multiple interfaces from different technologies and channel types. An important resource is the amount of memory intended for buffers. The quality of service perceived by the users are largely affected by the size of such buffers. This is because important network performance parameters such as packet loss probability, delay, and channel utilization are highly affected by the buffer sizes. An efficient use of memory for buffering, in addition to facilitate the mesh devices scalability, also prevents the problems associated with excessively large buffers. Most of the current works associate the buffer sizing problem with the dynamics of TCP congestion control mechanism. Since this work focuses on real time services, in which the use of TCP is unfeasible, this thesis proposes a dynamic buffer sizing mechanism mainly dedicated for such real time flows. The approach is based on the maximum entropy principle and allows that each device be able to dynamically self-configure its buffers to achieve more efficient memory utilization. The proper performance of the proposal has been extensively evaluated in wired and wireless interfaces. Classical infrastructure-based wireless and multi-hop mesh interfaces have been considered. Finally, when the WMN is built by the interconnection of user hand-helds, energy is a limited and scarce resource, and therefore any approach to optimize its use is valuable. For this case, this thesis proposes a topology control mechanism based on centrality metrics. The main idea is that, instead of having all the devices executing routing functionalities, just a subset of nodes are selected for this task. We evaluate different centralities, form both centralized and distributed perspectives. In addition to the common random mobility models we include the analysis of the proposal with a socially-aware mobility model that generates networks with a community structure.

Download or read book Performance Improvement Through Compression and Aggregation in Voice Over Wireless Mesh Network VoMESH written by Kyungtae Kim and published by . This book was released on 2006 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: The above performance optimization techniques are experimented in both the NS2 simulator and real testbed. The experimental results show an increase of around 13 times for a six hop string when all optimizations are used.

Download or read book Guide to Wireless Sensor Networks written by Sudip Misra and published by Springer Science & Business Media. This book was released on 2009-05-29 with total page 725 pages. Available in PDF, EPUB and Kindle. Book excerpt: Overview and Goals Wireless communication technologies are undergoing rapid advancements. The last few years have experienced a steep growth in research in the area of wireless sensor networks (WSNs). In WSNs, communication takes place with the help of spatially distributedautonomoussensornodesequippedtosensespeci?cinformation. WSNs, especially the ones that have gained much popularity in the recent years, are, ty- cally, ad hoc in nature and they inherit many characteristics/features of wireless ad hoc networks such as the ability for infrastructure-less setup, minimal or no reliance on network planning, and the ability of the nodes to self-organize and self-con?gure without the involvement of a centralized network manager, router, access point, or a switch. These features help to set up WSNs fast in situations where there is no existing network setup or in times when setting up a ?xed infrastructure network is considered infeasible, for example, in times of emergency or during relief - erations. WSNs ?nd a variety of applications in both the military and the civilian population worldwide such as in cases of enemy intrusion in the battle?eld, object tracking, habitat monitoring, patient monitoring, ?re detection, and so on. Even though sensor networks have emerged to be attractive and they hold great promises for our future, there are several challenges that need to be addressed. Some of the well-known challenges are attributed to issues relating to coverage and deployment, scalability, quality-of-service, size, computational power, energy ef?ciency, and security.

Download or read book Wireless Mesh Networks written by Nobuo Funabiki and published by BoD – Books on Demand. This book was released on 2011-01-14 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rapid advancements of low-cost small-size devices for wireless communications with their international standards and broadband backbone networks using optical fibers accelerate the deployment of wireless networks around the world. The wireless mesh network has emerged as the generalization of the conventional wireless network. However, wireless mesh network has several problems to be solved before being deployed as the fundamental network infrastructure for daily use. The book is edited to specify some problems that come from the disadvantages in wireless mesh network and give their solutions with challenges. The contents of this book consist of two parts: Part I covers the fundamental technical issues in wireless mesh network, and Part II the administrative technical issues in wireless mesh network,. This book can be useful as a reference for researchers, engineers, students and educators who have some backgrounds in computer networks, and who have interest in wireless mesh network. It is a collective work of excellent contributions by experts in wireless mesh network.