Mesh Networks

Mesh refers to an interlaced structure.

In networks, it refers to the many interconnection of nodes that can establish links to connect to others. Since all nodes are connected in a fluctuating web, devices can act as routers and forward traffic to others. This enables the content to hop between them until it reaches a destination. OR simply

A wireless mesh network (WMN) is a community-based internet network that provides an alternative model of internet access.

HOW IT WORKS — While the traditional networks rely on a small number of wired access points or wireless hotpots built and controlled by corporations, a mesh network depends on the interconnection of many “nodes” that route the internet across a community. A node is any device that can relay the connection on wards to its surrounding nodes, like a phone or a router.

Connection Arrangements

Within mesh networks, there are two connection arrangements: full mesh topologies or partial mesh topologies. These can be related to layer 3 of the OSI model. When the network is said to be full, each node is directly connected to all other nodes in the network. In contrast, a partial network is when only some nodes are connected to all the others, and others are only connected with the nodes with which they exchange the most data. Again, the two pictures bellow illustrate these two examples.

full and partial arrangements.

What are some pros and cons?

Mesh networks have both advantages and disadvantages just like anything else in tech.

• Freer access: The mesh network model allows free flow of information without moderation or selective rate control.
• Data can be transmitted from different devices simultaneously. This topology can withstand high traffic.
• More cost-effective: The bandwidth cost becomes cheaper as more people share it.
• More reliability: As more people participate and contribute to the network, the density of a mesh network adds reliability and speed. When one person leaves the network, the routing technology updates itself to provide access through a different point. In the case of an internet outage or shutdown, the mesh network can facilitates direct connections between computers without using the internet.
• Taking the network down is impossible unless there is some kind of worldwide catastrophe that wipes out all electronic devices in the world.

However, there are some major challenges as well.

• Security risks: The dissemination of information can pose privacy and security risks. (Note: NYC Mesh suggests for members to use standard precautions, such as using https websites for secure connections, or use a VPN service.)
• Market and regulatory forces make mesh networking difficult to deploy.
• The cost of deployment can sometimes be problematic in certain scenarios. However, it can be redeemed by downloading a software development kit, also called SDK’s, which enables you to become a participant node in the whole mesh instead of building it from scratch.
• Competition for supernode locations: Finding good locations to install supernodes can be expensive. Owners of tall buildings have become accustomed to charging high renter fees to big ISPs.
• Mesh networks are tough to manage and troubleshoot. For big networks, one needs a strong mesh technology to make it worthwhile. This can be difficult to find.

Applications of mesh networks?

South African wireless community networks are wireless networks that allow members to talk, send messages, share files and play games independent of the commercial landline and mobile telephone networks. Most of them use WiFi technology and many are wireless mesh networks. A wireless community network may connect to the public switched telephone network and/or the Internet, but there are various restrictions on connectivity in South Africa. Wireless community networks are particularly useful in areas where commercial telecommunications services are unavailable or unaffordable.

WMNs are really nothing new. In Spain, Catalan villages began setting up a country-wide mesh network called “Guifi.net” in 2003. It started as a community initiative to provide WiFi to residents in rural areas. The project steadily gained traction and expanded across the country, with community-owned fiber to sustain long distance WiFi connections. Today, Guifi.net has over 34,000 active nodes and about 50,000 km of wireless links.

In New York, a group of volunteers started a community-run internet network known as NYC Mesh. So far, NYC Mesh has installed two “supernodes,” one in downtown Manhattan an another in Bushwick, Brooklyn. These are large antennas are installed at internet exchange points (IXPs), physical network access points through which major ISPs connect get their internet. The supernodes are connected directly to the IXPs through fiber optic cable, essentially bypassing ISPs. Through mesh software, the supernodes are automatically connected to routers installed on rooftops and windows in nearby areas. The group has plans to install two more, but one volunteer estimates that there needs to be 30–40 super nodes to cover the entire city.