A new architecture for wireless LANs known as mesh networking has been generating a lot of buzz, and for good reason. Not only does it promise to make networks more robust, but it also brings costs down.
Instead of moving data from a device to a wireless access point to a wired network, a mesh network moves data from access point to access point, depending on availability and proximity, and then eventually onto a wired network. Mesh network traffic flows in much the same way that data travels across multiple points on the Internet before reaching a final destination.
In its most complex form, a mesh network could work like a peer-to-peer network, where devices both send their own data and forward data on for other devices. In an environment like that, the more devices on a network, the better the network functions.
On the most basic level, a mesh network is appealing to businesses and other organizations because it saves money on cabling, said Seamus McAteer, an analyst with the San Francisco-based research firm Zelos Group.
With a mesh network, a business only has to run a power cable, not a data cable, to most access points. The data is transmitted over the air from one access point to another until one finally ties into the hard-wired network. Using such a system, a network manager might only have to connect one of every five or 10 access points to the hard-wired network.
This wireless networking technique can be especially useful for old buildings, where cable can be expensive to lay, and in remote locations, McAteer said.
A mesh of vendors
A few companies are currently marketing mesh network products, including Firetide Inc., Tropos Networks Inc., Figure 8 Wireless Inc. and Maitland, Fla.-based MeshNetworks Inc. MeshNetworks offers both access points and handheld devices that use the mesh architecture. The company sells primarily to cities that are looking for reliable wireless communication systems for their public safety organizations.
MeshNetworks' system uses a proprietary air interface, called QDMA, that was developed by the Department of Defense. The high-throughput technology transmits over longer distances than does 802.11b. Because this system is proprietary, cities must install and manage their own networks, said MeshNetworks' chief technology officer, Peter Stanforth. It takes between four and nine access points to cover a square mile, at a cost of about $20,000.
These systems also require the use of MeshNetworks' handheld devices, which act as mini base stations. The devices can forward data just like access points, so the more handheld devices are in use, the better the system works, Stanforth said.
In order to avoid battery drain, Stanforth said, the network takes battery life into account in its routing decisions. Mesh devices need less power to transmit data, because they are often transmitting over short distances, he said.
Untangling the landscape
Dan Himes, national director of business development for Lakeland, Fla.-based Viasys Corp., uses mesh architectures in the networks that he designs for public transportation systems. These networks function by transmitting data from public buses, traffic lights and other traffic-related systems to a central office, so that lights can be remotely manipulated and public transportation systems can be monitored. Himes said that many of these organizations transmit video over their mesh networks as well.
Gerry Purdy, principal analyst with Cupertino, Calif.-base research firm MobileTrax, said that mesh architectures are likely to begin showing up in the home via televisions, stereos and thermostats. Homeowners might soon be able to adjust the temperature or turn on an electronic device in a different part of the house without using expensive or unsightly data cables.
But, he said, this is just the very beginning for mesh networks. Though no mesh networking standards are in place today, the Institute of Electrical and Electronics Engineers (IEEE), a well-known standards group, is now looking at the technology.
Jon Leary, a product line manager in Cisco Systems Inc.'s wireless LAN business unit, said that now is the time for the technology to occupy the IEEE's attention.
While some vendors are already moving ahead with products, Leary said, it is important to get a standard developed so that mesh networking systems made by different vendors can be interoperable.
While Cisco has no mesh networking products in development, he said that the technology has the potential to be one of a number of wireless architectures that IT managers may one day use. That day may be a ways off, though, since a standard is not likely to be established for another two years, he said.