Mesh Networking: High-impact Emerging Technology - What You Need to Know: Definitions, Adoptions, Impact, Benefits, Maturity, Vendors

Kevin Roebuck

Description

Mesh networking is a type of networking where each node must not only capture and disseminate its own data, but also serve as a relay for other sensor nodes, that is, it must collaborate to propagate the data in the network.

A mesh network can be designed using a flooding technique or a routing technique. When using a routing technique, the message propagates along a path, by hopping from node to node until the destination is reached. To ensure all its paths' availability, a routing network must allow for continuous connections and reconfiguration around broken or blocked paths, using self-healing algorithms. A mesh network whose nodes are all connected to each other is a fully connected network. Mesh networks can be seen as one type of ad hoc network. Mobile ad hoc networks (MANET) and mesh networks are therefore closely related, but MANET also have to deal with the problems introduced by the mobility of the nodes.

The self-healing capability enables a routing based network to operate when one node breaks down or a connection goes bad. As a result, the network is typically quite reliable, as there is often more than one path between a source and a destination in the network. Although mostly used in wireless scenarios, this concept is also applicable to wired networks and software interaction.

This book is your ultimate resource for Mesh Networking. Here you will find the most up-to-date information, analysis, background and everything you need to know.

In easy to read chapters, with extensive references and links to get you to know all there is to know about Mesh Networking right away, covering: Mesh networking, Optimized Link State Routing Protocol, B.A.T.M.A.N., Open Shortest Path First, Opportunity Driven Multiple Access, Peer-to-peer, Game Theory in Communication Networks, ZigBee, Optical mesh network, Netsukuku, Wireless mesh network, History of wireless mesh networking, BioWeb, Wireless ad hoc network, Wireless community network, Mobile ad hoc network, Vehicular ad-hoc network, Intelligent Vehicular ad-hoc Network, MeshBox, Meraki, Wizzy Digital Courier, Delay-tolerant networking, Network topology, Arbitrated loop, Broadcast radiation, Cambridge Ring, Channel capture effect, Connection-oriented Ethernet, Cube-connected cycles, Distributed Multi-Link Trunking, Distributed Split Multi-Link Trunking, Ethernet Exchange, Fat tree, Fibonacci cube, Fibre Channel point-to-point, Grid network, Hyperconnectivity, Hypertree network, Internet topology, InterSwitch Trunk, Linear topology, Logical topology, Mesh node, Metro Ethernet, Multi-link trunking, P2PRIV, Point-to-point (telecommunications), Public safety network, R-SMLT, Redundant topologies, Ring network, Ring Protection, Shared mesh, Spanning Tree Protocol, Split multi-link trunking, Star network, Switched fabric, Switched mesh, Switching loop, Szymanski's conjecture, Topology table, Token ring, Topology control, Tree and hypertree networks, Tree network, Virtual Cluster Switching (VCS), Virtual Link Aggregation Control Protocol

This book explains in-depth the real drivers and workings of Mesh Networking. It reduces the risk of your technology, time and resources investment decisions by enabling you to compare your understanding of Mesh Networking with the objectivity of experienced professionals.

Sujets

• Computers
• Informatique

Informations

• Publié par: Emereo Publishing
• Date de parution: 24 octobre 2012
• Nombre de lectures: 0
• EAN13: 9781743045381
• Langue: English
• Poids de l'ouvrage: 9 Mo

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Contents

Articles Mesh networking Optimized Link State Routing Protocol B.A.T.M.A.N. Open Shortest Path First Opportunity Driven Multiple Access Peer-to-peer Game Theory in Communication Networks ZigBee Optical mesh network Netsukuku Wireless mesh network

History of wireless mesh networking BioWeb Wireless ad hoc network Wireless community network Mobile ad hoc network Vehicular ad-hoc network Intelligent Vehicular ad-hoc Network MeshBox Meraki Wizzy Digital Courier Delay-tolerant networking Network topology Arbitrated loop Broadcast radiation Cambridge Ring Channel capture effect Connection-oriented Ethernet Cube-connected cycles Distributed Multi-Link Trunking Distributed Split Multi-Link Trunking Ethernet Exchange Fat tree Fibonacci cube

1 4 8 10 24 26 33 34 40 45 48 52 55 56 58 60 61 64 66 66 69 70 73 82 83 84 85 86 88 90 91 92 93 94

Fibre Channel point-to-point Grid network Hyperconnectivity Hypertree network Internet topology InterSwitch Trunk Linear topology Logical topology Mesh node Metro Ethernet Multi-link trunking P2PRIV Point-to-point (telecommunications) Public safety network R-SMLT Redundant topologies Ring network Ring Protection Shared mesh Spanning Tree Protocol Split multi-link trunking Star network Switched fabric Switched mesh Switching loop Szymanski's conjecture Topology table Token ring Topology control Tree and hypertree networks Tree network Virtual Cluster Switching (VCS) Virtual Link Aggregation Control Protocol

References Article Sources and Contributors Image Sources, Licenses and Contributors

97 97 98 100 101 103 104 104 105 105 110 111 112 113 114 115 116 117 118 119 128 131 133 134 134 135 136 136 141 144 153 161 163

164 168

Article Licenses License

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Mesh networking

Mesh networking

Mesh networking (topology)is a type of networking where each node must not only capture and disseminate its own data, but also serve as arelayfor other sensor nodes, that is, it must collaborate to propagate the data in the network. A mesh network can be designed using afloodingtechnique or aroutingtechnique. When using a routing technique, the message propagates along a path, byhoppingfrom node to node until the destination is reached. To ensure all its paths' availability, a routing network must allow for continuous connections and reconfiguration around broken or blocked paths, usingself-healingalgorithms. A mesh network whose nodes are all connected to each other is a fully connected network. Mesh networks can be seen as one type of ad hoc network. Mobile ad hoc networks (MANET) and mesh networks are therefore closely related, but MANET also have to deal with the problems introduced by the mobility of the nodes. The self-healing capability enables a routing based network to operate when one node breaks down or a connection goes bad. As a result, the network is typically quite reliable, as there is often more than one path between a source and a destination in the network. Although mostly used in wireless scenarios, this concept is also applicable to wired networks and software interaction.

Wireless mesh networks Wireless mesh networks were originally developed for military applications and are typical of mesh architectures. Over the past decade the size, cost, and power requirements of radios has declined, enabling more radios to be included within each device acting as a mesh node. The additional radios within each node enable it to support multiple functions such as client access, backhaul service, and scanning (required for high speed handover in mobile applications). Additionally, the reduction in radio size, cost, and power has enabled the mesh nodes to become more modular—one node or device now can contain multiple radio cards or modules, allowing the nodes to be customized to handle a unique set of functions and frequency bands. Work in this field has been aided by the use of game theory methods to analyze strategies for the allocation of [1] resources and routing of packets.

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Mesh networking

Examples

In early 2007, the US-based firm Meraki launched a mini wireless [2] mesh router. This is an example of a wireless mesh network (on a claimed speed of up to 50 megabits per second). The 802.11 radio within the Meraki Mini has been optimized for long-distance communication, providing coverage over 250 metres. This is an example of a single-radio mesh network being used within a community as opposed to multi-radio long range mesh networks like [3] [4] BelAir or MeshDynamics that provide multifunctional infrastructure.

The Naval Postgraduate School, Monterey CA, demonstrated a [5] wireless mesh network for border security. In a pilot system, aerial cameras kept aloft by balloons relayed real time high resolution video to ground personnel via a mesh network.

An MIT Media Lab project has developed the XO-1 laptop or "OLPC"(One Laptop per Child) which is intended for disadvantaged schools in developing nations and uses mesh networking (based on the Building a Rural Wireless Mesh Network: A DIY Guide (PDF) IEEE 802.11s standard) to create a robust and inexpensive [6] infrastructure. The instantaneous connections made by the laptops are claimed by the project to reduce the need for an external infrastructure such as the Internet to reach all areas, because a connected node could share the connection with nodes nearby. A similar concept has also been [7] implemented by Greenpacket with its application called SONbuddy.

In Cambridge, UK, on the 3rd June 2006, mesh networking was used at the“Strawberry Fair”to run mobile live [8] television, radio and Internet services to an estimated 80,000 people. The Champaign-Urbana Community Wireless Network (CUWiN) project is developing mesh networking software based on open source implementations of the Hazy-Sighted Link State Routing Protocol and Expected Transmission [9] Count metric. Additionally, the Wireless Networking Group in the University of Illinois at Urbana-Champaign are developing a multichannel, multi-radio wireless mesh testbed, called Net-X as a proof of concept implementation of some of the multichannel protocols being developed in that group. The implementations are based on an architecture that allows some of the radios to switch channels to maintain network connectivity, and includes protocols for [10] channel allocation and routing. SMesh is an 802.11 multi-hop wireless mesh network developed by the Distributed System and Networks Lab at [11] Johns Hopkins University. A fast handoff scheme allows mobile clients to roam in the network without interruption in connectivity, a feature suitable for real-time applications, such as VoIP. Many mesh networks operate across multiple radio bands. For example Firetide and Wave Relay mesh networks have the option to communicate node to node on 5.2 GHz or 5.8 GHz, but communicate node to client on 2.4 GHz (802.11). This is accomplished using SDR (Software-Defined radio.) The SolarMESH project examined the potential of powering 802.11-based mesh networks using solar power and [12] rechargeable batteries. Legacy 802.11 access points were found to be inadequate due to the requirement that are [13] continuously powered. The IEEE 802.11s standardization efforts are considering power save options, but solar-powered applications might involve single radio nodes where relay-link power saving will be inapplicable. [14] The WING project (sponsored by the Italian Ministry of University and Research and led by CREATE-NET and Technion) developed a set of novel algorithms and protocols for enabling wireless mesh networks as the standard access architecture for next generation Internet. Particular focus has been given to interference and traffic aware

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Mesh networking

channel assignment, multi-radio/multi-interface support, and opportunistic scheduling and traffic aggregation in highly volatile environments. Recent standards for wired communications have also incorporated concepts from Mesh Networking. An examples is ITU-T G.hn, a standard that specifies a high-speed (up to 1 Gigabit/s) local area network using existing home wiring (power lines, phone lines and coaxial cables). In noisy environments such as power lines (where signals can be heavily attenuated and corrupted by noise) it's common that mutual visibility between devices in a network is not complete. In those situations, one of the nodes has to act as a relay and forward messages between those nodes that cannot communicate directly, effectively creating a mesh network. In G.hn, relaying is performed at the Data Link Layer.

Technical challenges • Wizzy Digital Courier • Delay-tolerant networking

References [1] J. Huang, D. P. Palomar, N. Mandayam, J. Walrand, S. B. Wicker, and T. Basar, "Game Theory in Communication Systems",IEEE Journal on Selected Areas in Communications, Vol. 26 No. 7, Sep. 2008. Link (http://www.jsac.ucsd.edu/TOC/2008/September08cover.pdf) [2] "Meraki Mesh" (http://web.archive.org/web/20080219155800/http://meraki.com/oursolution/mesh/). meraki.com. Archived from the original (http://meraki.com/oursolution/mesh/) on 2008-02-19. . Retrieved 2008-02-23. [3] "Muni WiFi Mesh Networks" (http://www.belairnetworks.com). belairnetworks.com. . Retrieved 2008-02-23. [4] "Meshdynamics : Highest performance Voice, Video and Data Outdoors" (http://www.meshdynamics.com). meshdynamics.com. . Retrieved 2008-02-23. [5] Robert Lee Lounsbury, Jr. (PDF).OPTIMUM ANTENNA CONFIGURATION FOR MAXIMIZING ACCESS POINT RANGE OF AN IEEE 802.11 WIRELESS MESH NETWORK IN SUPPORT OF MULTIMISSION OPERATIONS RELATIVE TO HASTILY FORMED SCALABLE DEPLOYMENTS(http://theses.nps.navy.mil/07Sep_Lounsbury.pdf). . Retrieved 2008-02-23. [6] "XO-1 Mesh Network Details" (http://wiki.laptop.org/go/Mesh_Network_Details). laptop.org. . Retrieved 2008-02-23. [7] "SONbuddy : Network without Network" (http://www.sonbuddy.com). sonbuddy.com. . Retrieved 2008-02-23. [8] "Cambridge Strawberry Fair" (http://www.cambridgeshiretouristguide.com/Articles/Article_55.asp). cambridgeshiretouristguide.com. . Retrieved 2008-02-23. [9] "Wireless Networking Group" (http://www.crhc.illinois.edu/wireless/netx.html). . [10] "Wireless Networking Group" (http://www.crhc.illinois.edu/wireless/papers/kyasanur2006Tech.pdf). . [11] "SMesh" (http://smesh.org). smesh.org. . Retrieved 2008-02-23. [12] "SolarMesh" (http://owl.mcmaster.ca/~todd/SolarMESH). mcmaster.ca. . Retrieved 2008-04-15. [13] Terence D. Todd, Amir A. Sayegh, Mohammed N. Smadi, and Dongmei Zhao. The Need for Access Point Power Saving in Solar Powered WLAN Mesh Networks (http://ieeexplore.ieee.org/search/freesrchabstract.jsp?arnumber=4519963&isnumber=4519956& punumber=65&k2dockey=4519963@ieeejrns). In IEEE Network, May/June 2008. [14] http://www.wing-project.org WING

External links • Smart Multi-Grid Wifi Mesh (http://www.meshdynamics.com/documents/smart-multi-grid-network.pdf): Integrated wifi mesh network provides metering, traffic safety, wifi access to communities in US. • MIT Roofnet (http://www.pdos.lcs.mit.edu/roofnet/) A research project at MIT that forms the basis of roofnet / Meraki mesh networks • WING Project (http://www.wing-project.org) Wireless Mesh Network distribution based on the roofnet source code • Miners Give a Nod to Nodes (http://www.meshdynamics.com/documents/Mesh_Mining_July08.pdf) Reprint from Mission Critical Magazine on successful deployment of mesh in mines • DARPA's ITMANET program and the FLoWS Project (http://www.mit.edu/~medard/itmanet) Investigating Fundamental Performance Limits of MANETS

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Mesh networking

• Robin Chase discusses Zipcar and Mesh networking (http://www.ted.com/talks/view/id/212) Robin Chase talks at the Ted conference about the future of mesh networking and eco-technology • Mesh Networks Research Group (http://www.mesh-networks.org/) Projects and tutorials' compilation related to the Wireless Mesh Networks • Phantom (http://code.google.com/p/phantom/) anonymous, decentralized network, isolated from the Internet

Optimized Link State Routing Protocol

[1] TheOptimized Link State Routing Protocol (OLSR)is an IP routing protocol optimized for mobile ad-hoc networks, which can also be used on other wireless ad-hoc networks. OLSR is a proactive link-state routing protocol, which uses Hello and Topology Control (TC) messages to discover and then disseminate link state information throughout the mobile ad-hoc network. Individual nodes use this topology information to compute next hop destinations for all nodes in the network using shortest hop forwarding paths.

Features specific to OLSR Link-state routing protocols such as OSPF and IS-IS elect adesignated routeron every link to perform flooding of topology information. In wireless ad-hoc networks, there is different notion of a link, packets can and do go out the same interface; hence, a different approach is needed in order to optimize the flooding process. Using Hello messages the OLSR protocol at each node discovers 2-hop neighbor information and performs a distributed election of a set ofmultipoint relays(MPRs). Nodes select MPRs such that there exists a path to each of its 2-hop neighbors via a node selected as an MPR. These MPR nodes then source and forward TC messages that contain the MPR selectors. This functioning of MPRs makes OLSR unique from other link state routing protocols in a few different ways: The forwarding path for TC messages is not shared among all nodes but varies depending on the source, only a subset of nodes source link state information, not all links of a node are advertised but only those that represent MPR selections. Since link-state routing requires the topology database to be synchronized across the network, OSPF and IS-IS perform topology flooding using a reliable algorithm. Such an algorithm is very difficult to design for ad-hoc wireless networks, so OLSR doesn't bother with reliability; it simply floods topology data often enough to make sure that the database does not remain unsynchronized for extended periods of time.

Benefits Being a proactive protocol, routes to all destinations within the network are known and maintained before use. Having the routes available within the standard routing table can be useful for some systems and network applications as there is no route discovery delay associated with finding a new route. The routing overhead generated, while generally greater than that of a reactive protocol, does not increase with the number of routes being used. Default and network routes can be injected into the system by HNA messages allowing for connection to the internet or other networks within the OLSR MANET cloud. Network routes are something reactive protocols do not currently execute well. Timeout values and validity information is contained within the messages conveying information allowing for differing timer values to be used at differing nodes.

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Optimized Link State Routing Protocol

Criticisms The original definition of OLSR does not include any provisions for sensing of link quality; it simply assumes that a link is up if a number of hello packets have been received recently. This assumes that links are bi-modal (either working or failed), which is not necessarily the case on wireless networks, where links often exhibit intermediate rates of packet loss. Implementations such as the open source OLSRd (commonly used on Linux-based mesh routers) have been extended (as of v. 0.4.8) with link quality sensing. Being a proactive protocol, OLSR uses power and network resources in order to propagate data about possibly unused routes. While this is not a problem for wired access points, and laptops, it makes OLSR unsuitable for sensor networks that try to sleep most of the time. For small scale wired access points with low CPU power, the open source [2] OLSRd project showed that large scale mesh networks can run with OLSRd on thousands of nodes with very little CPU power on 200 MHz embedded devices. Being a link-state protocol, OLSR requires a reasonably large amount of bandwidth and CPU power to compute optimal paths in the network. In the typical networks where OLSR is used (which rarely exceed a few hundreds of nodes), this does not appear to be a problem. By only using MPRs to flood topology information, OLSR removes some of the redundancy of the flooding process, [3] which may be a problem in networks with moderate to large packet loss rates - however the MPR mechanism is self-pruning (which means that in case of packet losses, some nodes that would not have retransmitted a packet, may do so).

Messages OLSR makes use of "Hello" messages to find its one hop neighbors and its two hop neighbors through their responses. The sender can then select its multipoint relays (MPR) based on the one hop node that offers the best routes to the two hop nodes. Each node has also an MPR selector set, which enumerates nodes that have selected it as an MPR node. OLSR uses Topology Control (TC) messages along with MPR forwarding to disseminate neighbor information throughout the network. Host and Network Association (HNA) messages are used by OLSR to disseminate network route advertisements in the same way TC messages advertise host routes.

Hello

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Optimized Link State Routing Protocol

TC (Topology Control)

Other approaches The problem of routing in ad-hoc wireless networks is actively being researched, and OLSR is but one of several proposed solutions. To many, it is not clear whether a whole new protocol is needed, or whether OSPF could be [4] [5] extended with support for wireless interfaces. In bandwidth- and power-starved environments, it is interesting to keep the network silent when there is no traffic to be routed. Reactive routing protocols do not maintain routes, but build them on demand. As link-state protocols require database synchronisation, such protocols typically use the distance vector approach, as in AODV and DSDV, or more ad-hoc approaches that do not necessarily build optimal paths, such as Dynamic Source Routing. For more information see the list of ad-hoc routing protocols.

OLSR version 2 OLSRv2 is currently being developed within the IETF. It maintains many of the key features of the original including MPR selection and dissemination. Key differences are the flexibility and modular design using shared components: packet format packetbb, and neighborhood discovery protocol NHDP. These components are being designed to be common among next generation IETF MANET protocols. Differences in the handling of multiple address and interface enabled nodes is also present between OLSR and OLSRv2.

Implementations [6] • OLSR.ORG - Downloadable code for OLSR on GNU/Linux, Windows, Mac OS X, FreeBSD and NetBSD systems. Features a great deal of documentation, including an informative survey of related work. [7] • NRL-OLSR - Open source code of NRL-OLSR. Works on Windows, MacOS, Linux, and various embedded PDA systems such as Arm/Zaurus and PocketPC as well as simulation environments ns2 and OPNET., http://cs. itd.nrl.navy.mil/focus/ [8] • SOURCEFORGE.NET-OLSR - Created by MOVIQUITY and based on studies within the project Workpad, it offers a code in C# to deploy a MANET (Ad-Hoc, Meshnet) with protocol OLSR. Developed for WM 6, Win XP and can be adapted to other platforms using NET Framework and Compact http://sourceforge.net/projects/ wmolsr/

External links [9] • IETF Home Page The Internet Engineering Task Force standards body [10] • olsr.funkfeuer.at currently advancing the olsr.org implementation to improve scalability [11] [12] • Optimized Link State Routing , which includes this Flash Demo . [13] • Freifunk Firmware (English language page) - a firmware based on OpenWRT that uses OLSR, designed to build mesh networks out of wireless access points, e.g. LinksysWRT54G's [14] [15] • Pyramid Linux - an embedded distro for embedded x86 boards with OLSR, web interface, etc. Primarily used in Community Networks.

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