Multipath Routing

Wireless networking and computing systems have revolutionized the way people think about wireless communication. Very recently we have witnessed the enormous growth of mobile phone usage by virtue of the development in the cellular wireless communication. Yet another shorter range communication based on packet radio network has already established its feet in the ground. Completely wireless corporations, campuses, hotzones or even communities now might not be too far from the reality. Massive consumption of the IEEE 802.11a/b/g wireless cards and access points have shown that the thirst for wireless communication is on rise. Deployment of notebook PCs, PDAs and hand held computing systems are simply going to add more demand on the need of wireless specifically against the cables that must be streched from the distance. However, the thirst of going into complete wireless has not been fulfilled and users still desparately have to depend upon the wired connection.

The foremost reason is the mediocre capacity that is available for the data communication. The following table shows the bound on capacity of the avaialble network for data communication. Evidently, most of the current research in the different sectors of the wireless communication is focused on breaking every possible bounds on capacity[][]. In this regard, a new communication paradigmn has emerged, a wireless mesh network (WMN).

Introducing WMN of different scales might not be feasible right here so I keep my concentration within the bounds of wireless local area networks. Wireless mesh network for wireless LAN (WLAN mesh) is the upcoming technology, where a backbone of infrastructure routers will support the surrounding stations. Getting its birth from the concept of already well known ad hoc networks, WLAN mesh blends many other features from the current WLAN architecture, so as to say.. to give more capacity to the users for using the network.

The legacy wireless LAN architecure has one access point, normally connected to wireline and stations connected to it. Access point serve as a gateway for stations to get connected with the local area network, or be part of it aswell as the connection to the Internet. To be more precise, stations must be configured to a particular AP for getting access to the network services. So it forms a one level tree like structure with one root AP and theoritically any number of stations as leaves. Now in this envrionment, what are the goodies package brought by WLAN mesh?

Previously, in the WLAN architecture there is no exact definition of how APs can communicate with each other in the wireless environment. The infrastructure mesh network gives the right answer. Many wireless APs now can communicate with eachother with a well defined protocol. We are simply offered with more number of links and eventually more capacity. Further, any nodes can somewhat act like APs. For example a PC in a room can participate to perform like APs. It gives stations more flexibility to choose better access points.

To be continued...