Mesh networking

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Mesh networking' is a way to route data, voice and instructions between nodes. It allows for continuous connections and reconfiguration around broken or blocked paths by “hopping” from node to node until the destination is reached. A mesh network whose nodes are all connected to each other is a fully connected network. Mesh networks differ from other networks in that the component parts can all connect to each other via multiple hops, and they generally are not mobile. Mesh networks can be seen as one type of ad hoc network. Mobile ad-hoc networking (MANet), and mesh networking are therefore closely related, but mobile ad hoc networks also have to deal with the problems introduced by the mobility of the nodes.

Mesh networks are self-healing: the network can still operate even when a node breaks down or a connection goes bad. As a result, a very reliable network is formed. This concept is applicable to wireless networks, wired networks, and software interaction. An animation of a wireless mesh network is shown on the right. Watch what happens when the mesh nodes power up (green LED on box turns on). The nodes hear each other's broadcast and a network is automatically formed. Also watch what happens when a node fails. The nodes re-discover an alternate routing path. Network connectivity is thus preserved automatically.

Wireless mesh networks is the most topical application of mesh architectures. Wireless mesh was originally developed for military applications but have undergone significant evolution in the past decade. Wireless mesh networking has seen three distinct radio configurations of mesh technology, each incorporating iterative improvements allowing for greater reliability and versatility. As the cost of radios plummeted, single radio products evolved to support more radios per mesh node with the additional radios providing specific functions- such as client access, backhaul service or scanning radios for high speed handover in mobility applications. The mesh node design also became more modular - one box could support multiple radio cards - each operating at a different frequency. As a result, a whole new set of applications are being enabled by third generation mesh networking technology. These include real time video surveillance, border security or voice communication inside underground mines.

Examples

In early 2007, the US-based firm Meraki launched a mini wireless 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 meters. 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 Belair or MeshDynamics that provide multifunctional infrastructure. The Naval Postgraduate School, Monterey CA, demonstrated a 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.

A MIT Media Lab project has developed the XO-1 laptop or "OLPC" which is intended for under-privileged schools in developing nations and uses mesh networking (based on the IEEE 802.11s standard) to create a robust and inexpensive 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 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 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 Count metric.

SMesh is an 802.11 multi-hop wireless mesh network developed by the Distributed System and Networks Lab at 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.

See also

Mesh network applications

• Wireless mesh network
• Distinct radio node deployments of Wireless Mesh Networking
• BioWeb
• Wireless ad-hoc network
• Wireless community network
• Mobile ad-hoc network
• Vehicular ad-hoc network
• Intelligent Vehicular AdHoc Network refer Google Groups-INADVENC

Mesh network devices

• MeshBox

Technical challenges

• Wizzy Digital Courier
• Delay Tolerant Networking

External links

• Analysis of Mesh Architectures Why all mesh products are not created equal.
• The Mesh DebateDailywireless Article on Structured mesh network scalability.
• Military Mesh Networks What makes military mesh networking requirements distinct
• MIT Roofnet A research project at MIT that forms the basis of roofnet / Meraki mesh networks
• Ugly Truths About Mesh Networks Performance issues of First and Second Generation Mesh products.
• Wireless Mesh Networks Advantages and applications for Industrial and Mobile Solutions
• Moskaluk Wireless Mesh Don Moskaluk Mesh network documentation and monitoring for Locustworlds Open Source AODV
• DARPA's ITMANET program and the FLoWS Project Investigating Fundamental Performance Limits of MANETS
• Protocol Investigations Scalability analysis of a commerical protocol
• Robust Wireless Mesh Communications inside mines - successful pilots

References

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Last updated on Wednesday March 12, 2008 at 10:35:50 PDT (GMT -0700)
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