February 02, 2004, 11:46 AM — If you've not been hearing lots about wireless meshes lately, you soon will be. In 2001, Farpoint Group picked wireless meshes as one of the most important wireless technologies for this decade. And we stand by that prediction - wireless meshes are now beginning to have an impact across many markets and applications, and their reach and importance will only increase over time.
What is a (not necessarily wireless) mesh? Well, it's a very general form of network, not unlike the Internet. In the Internet, many nodes are both end points as well as relay points for other traffic. In other words, each node behaves like a router (and is usually implemented as or with a router), forwarding traffic as is appropriate along the best route at the time. Meshes trace their history to a branch of finite mathematics called graph theory, and, as a computer science major, I spent many happy (and not-so-happy) hours exploring all of the intricacies of this fascinating little world. It's great to see the theory applied so elegantly, as is the case with wireless meshes. By the way, if you're interested in graph theory, which has great application to networks in general, see this, and there are also many other good references on the Web.
A wireless mesh is a mesh network like any other, but the links between nodes are implemented with a radio of some form. This means, most importantly, that the number of possible links between a given node and any other is potentially much greater than in a wired network, since the actual configuration of a particular wireless mesh need not be determined until it is actually moving data. Paths through the network can change from moment to moment in response to varying traffic loads, radio conditions, or traffic prioritization. Wireless meshes are thus among the most flexible network structures ever created, and this amazingly adaptable and applicable to many different missions, applications, and markets.
We've developed a taxonomy of sorts for wireless meshes, and, as you are about to see, the degree of variation possible in them is quite remarkable. The key characteristics of and alternatives in wireless meshes are as follows:
- Dynamic/self-organizing/adaptive or static/deterministic - A wireless mesh can be re-configured on the fly to account for those conditions listed above, and also allow for reconfiguration in the event that a given node fails or moves out of range of all other nodes. On the other hand, it's also possible to pre-configure an unchanging wireless mesh, in which case it behaves just like most wired networks