摘要 :
Wireless Mesh Networks (WMNs) consist of several Access Points (APs) of Wireless Local Area Networks (WLANs) interconnected through wireless links. It is necessary to monitor the networks in order to properly operate WMNs. However...
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Wireless Mesh Networks (WMNs) consist of several Access Points (APs) of Wireless Local Area Networks (WLANs) interconnected through wireless links. It is necessary to monitor the networks in order to properly operate WMNs. However, it is very difficult to always monitor WMNs. Although several researches for visualization system of WMNs were done, there are some problems such as lack of dynamic information and past information. The authors 'previous system also had problems such as lack of visualization information and inefficient information collection method. In this paper, they propose an extended visualization system for WMNs called Mesh Net Viewer Ⅱ (MNVⅡ). MNVⅡ can visualize not only network topology and link stability degree but also packet flow, route information and past information of WMNs. Furthermore, the authors have improved visualization information collection method of their previous system. In the performance evaluation, the authors verified visualization accuracy and real time characteristics of MNVⅡ.
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摘要 :
Wireless Mesh Networks (WMNs) have recently gained increasing attention and have emerged as a technology with great potential for a wide range of applications. WMNs can be considered as a superset of traditional mobile ad-hoc netw...
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Wireless Mesh Networks (WMNs) have recently gained increasing attention and have emerged as a technology with great potential for a wide range of applications. WMNs can be considered as a superset of traditional mobile ad-hoc networks (MANETs), where the network is comprised of mobile client devices MESH_CLIENTs. In addition to MESH_CLIENTs, a WMN can also contain relatively static devices called mesh routers (MESH_ROUTERs). Such hybrid WMN are characterized by a high level of heterogeneity, since static MESH_ROUTERs are typically much less resource constrained than mobile MESHjCLlENTs, and are also often equipped with multiple radio interfaces. Traditional ad-hoc routing protocols do not differentiate between these types of nodes and therefore cannot achieve optimal performance in hybrid WMNs. In this paper, we propose simple extensions to the Ad-hoc On-demand Distance Vector (AODV) routing protocol, which aim to take advantage of the heterogeneity in hybrid WMNs by preferentially routing packets via paths consisting of high capacity MESH_ROUTERs. In addition, we implement a simple channel selection scheme that reduces interference and maximizes channel diversity in multi-radio WMNs. Our simulation results show that in hybrid WMNs, our extensions result in significant performance gains over the standard AODV protocol.
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Wireless mesh networks in general, and WiFi mesh networks in particular, offer a cost-effective option to provide broadband connectivity in sparse regions. Effective support for real-time as well as high throughput applications re...
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Wireless mesh networks in general, and WiFi mesh networks in particular, offer a cost-effective option to provide broadband connectivity in sparse regions. Effective support for real-time as well as high throughput applications requires a TDMA-based approach. However, multihop TDMA implementations in wireless have been few and far-between, and for good reasons. These present significant issues in terms of time synchronization, TDMA schedule dissemination, multichannel support, routing integration, spatial reuse and so on. And achieving these efficiently, in the face of wireless channel losses presents a formidable challenge. In this work, we present an implementation of LiT MAC, a full-fledged multihop TDMA MAC, on commodity WiFi platforms. We undertake extensive evaluations using microbenchmarks as well as application level performance, using outdoor as well as indoor testbeds. We also present an integration of LiT MAC with various routing metrics, and a routing stability study of recently proposed routing metrics (ROMA, SLIQ). Our results show that we can achieve $(rm mu s)$ granularity time synchronization across several hops, and TDMA slot size as small as 2 ms. These imply low control overheads. Experiments over several days, on our nine-node outdoor testbed shows that LiT MAC's soft-state-based approach is effective in robust operation even in the presence of significant external interference.
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The Internet Protocol is the dominant network protocol used in public networks today and has proven to be highly effective for wired networks and wireless networks alike, provided network address allocation can be coordinated. Mes...
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The Internet Protocol is the dominant network protocol used in public networks today and has proven to be highly effective for wired networks and wireless networks alike, provided network address allocation can be coordinated. Mesh networks consisting of highly mobile devices present new challenges, especially when the assumption of coordination does not apply. One situation where coordination is not readily possible is ad-hoc networks in isolated areas and in disaster zones, both of which are characterized by deprivation of infrastructure. This study describes our realizations of several problems that IPv4 and IPv6 networking faces in such contexts and provides a brief description of an alternative network architecture for such situations, the Serval Network Layer and provides some of the reasoning behind the design decisions made. The Serval Network Layer is implemented as an open-source user-space network layer with strong intrinsic security characteristics and is able to be deployed without any centralized coordination.
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The IEEE 802.16 standard (WiMAX) specifies a MeSH mode which permits the deployment of Wireless Mesh Networks (WMNs) supporting carrier-grade QoS. The network operator for such planned WMNs is interested in maximizing the traffic ...
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The IEEE 802.16 standard (WiMAX) specifies a MeSH mode which permits the deployment of Wireless Mesh Networks (WMNs) supporting carrier-grade QoS. The network operator for such planned WMNs is interested in maximizing the traffic admitted in the WMN and simultaneously supporting QoS. Recently network coding has emerged as a promising technique for increasing the throughput in WMNs. This paper proposes CORE, which addresses the problem of jointly optimizing the routing, scheduling, and bandwidth savings via network coding. Prior solutions are either not applicable in the 802.16 MeSH mode or computationally too costly to be of practical use in the WMN under realistic scenarios. CORE's heuristics, in contrast, are able to compute solutions for the above problem within a operator definable maximum computational cost, thereby enabling the computation and near real-time deployment of the computed solutions. We analyze the performance of CORE's heuristics via a thorough simulation study covering the typical usage scenarios for WMNs. The results presented demonstrate that CORE is able to increase the number of flows admitted considerably and with minimal computational costs. We also see that CORE successfully increases the number of network coding sessions which can be established in the WMN. Further, the results provide insights into limiting factors for the gains which can be obtained in different typical usage scenarios for WMNs.
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This paper presents a collection of approximation formulas that allow a network planner to quickly estimate the size of a mesh optical network with limited inputs. In particular, it provides a set of equations that relate number o...
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This paper presents a collection of approximation formulas that allow a network planner to quickly estimate the size of a mesh optical network with limited inputs. In particular, it provides a set of equations that relate number of sites, average fiber connectivity, demand load and capacity for various mesh protection architectures. These results can be used to easily and quickly estimate the amount of traffic that can be carried over a given network, or, conversely, given the traffic to be supported, to assess the characteristics of the topology required (in terms of number of nodes, connectivity). Finally, this analysis can be used to estimate the restoration performance that can be expected without resorting to extensive simulation studies.
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This work evaluates sporadic data collection on a Bluetooth Mesh network, using the OMNET++ INET simulator. The data collector is a roaming sink node, which could be a smartphone or other portable device, carried by a pedestrian, ...
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This work evaluates sporadic data collection on a Bluetooth Mesh network, using the OMNET++ INET simulator. The data collector is a roaming sink node, which could be a smartphone or other portable device, carried by a pedestrian, a biker, an animal, or a drone. The sink node could connect to a mesh network in hard-to-reach areas that do not have internet access and collect sensor data. After implementing Bluetooth Mesh relay extensions, Low Power, and Friend features in OMNET++, we were able to propose and evaluate algorithms for mobility-aware, adaptive, routing of sensor data towards the sink node. One variation of a proposed routing algorithm achieved a 173.54% increase in unique data delivered to the sink node compared to Bluetooth Mesh's default routing algorithm. In that case, there was only a 4.63% increase in energy consumption for the same scenario. Also, the delivery rate increased by 111.82%.
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Nowadays, network technologies are developing very rapidly. The growing volume of transmitted information (video, data, VoIP, etc.), the physical growth of networks, and inter-network traffic are forcing manufacturers to produce m...
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Nowadays, network technologies are developing very rapidly. The growing volume of transmitted information (video, data, VoIP, etc.), the physical growth of networks, and inter-network traffic are forcing manufacturers to produce more powerful and "smart" devices that use new methods of transferring and sorting data. Such connected smart devices (IoT) are used in intelligently controlled traffic for self-driving vehicles in Vehicle Adhoc Networks (VANET), in electricity and water in smart cities, and in-home automation in smart homes. These types of connected Internet of Things (IoT) devices are used to leverage different types of network structures. Such IoT sensor devices can be deployed as a wireless sensor network (WSN) in a mesh topology. Both WSNs and Wireless Mesh Networks (WMNs) are easy to organize as well as to deploy. In this case, there are many reasons for combining these different types of networks. In particular, the detailed sensory capabilities of sensor networks may be improved by increasing bandwidth, reliability and power consumption in the mesh topology. However, there are currently only a handful of studies devoting to integrate these two different types of networks. In addition, there is no systematic review of existing interconnection methods. That is why in this article we explore the existing methods of these two networks and provide an analytical basis for their relationship. We introduce the definition of WSN and WMN and then look at some case studies. Afterward, we present several challenges and opportunities in the area of combined Wireless Mesh Sensor Network (WMSN) followed by a discussion on this interconnection through literature review and hope that this document will attract the attention of the community and inspire further research in this direction.
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While WiFi was initially designed as a local-area access network, mesh networking technologies have led to increasingly expansive deployments of WiFi networks. In urban environments, the WiFi mesh frequently supplements a number o...
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While WiFi was initially designed as a local-area access network, mesh networking technologies have led to increasingly expansive deployments of WiFi networks. In urban environments, the WiFi mesh frequently supplements a number of existing access technologies, including wired broadband networks, 3G cellular, and commercial WiFi hotspots. It is an open question what role citywide WiFi deployments play in the increasingly diverse access network spectrum. We study the usage of the Google WiFi network deployed in Mountain View, CA, and find that usage naturally falls into three classes based almost entirely on client device type, which we divide into traditional laptop users, fixed-location access devices, and PDA-like smartphone devices. Moreover, each of these classes of use has significant geographic locality, following the distribution of residential, commercial, and transportation areas of the city. When comparing the network usage of each device class, we find a diverse set of mobility patterns that map well to the archetypal use cases for traditional access technologies. To help place our results in context, we also provide key performance measurements of the mesh backbone and, where possible, compare them to those of previously studied urban mesh networks.
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The article presents innovative methods for designing and controlling topology in mesh networks. The authors of the paper simulate the procedure of deploying a mesh structure and prove that the shortest path for such a network is ...
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The article presents innovative methods for designing and controlling topology in mesh networks. The authors of the paper simulate the procedure of deploying a mesh structure and prove that the shortest path for such a network is also one with the least number of hops in the sense of intermediate nodes.
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