Building wireless mesh networks using ARM development boards (i)

As a result of the project, the boss asked me to build a wireless mesh network using the ARM Development Board (tiny6410 of friendly arm). Generally speaking, the network equipment of the wireless self-organization network is to be acted by the user's terminal apparatus, these terminal equipment must handle the user's application data, such as entertainment, office and so on all aspects data, but also acts as the router, carries on the route forwarding; For the former, most of the hardware and software resources of the terminal equipment are spent on the user's application data processing, leaving the network forwarding use of resources, so these devices are generally not competent for large-scale network topology, large data volume (such as audio, video multimedia data) forwarded these tasks; for the latter, The high mobility of terminal equipment will cause the problem of power supply (generally will use battery to power supply, battery capacity is quite limited), so terminal equipment in the manufacturing, it is not possible to choose a strong processor, because the processor processing power, the greater the power consumption, the battery can not meet their needs, in addition, The mobile of the terminal is very strong also will make the whole network topology change very big, the network is unstable.

In order to solve the above problems, wireless mesh network emerged. The wireless mesh network is essentially a wireless self-organizing Network (ADHOC), except that the wireless mesh network abstracts a backbone (mesh) on the basis of adhoc. Unlike the Adhoc network, all nodes are assumed by the user's terminal equipment, and all nodes are fully equivalent to each other, with strong mobility. The backbone of the wireless mesh network is composed of specialized network equipment (routers, etc.), and these devices that make up the backbone network are generally not mobile or weak mobility. This will solve many of the problems faced by these adhoc networks. First, the backbone node is dedicated to the routing equipment, these routing devices do not have to process the user's application data, only for the task of routing and forwarding, so all the hardware and software resources are for routing forwarding service, Therefore can assume the large topological structure (large topology network first needs the network equipment has enough storage space to store the huge routing table, but also needs the strong processor to find or update the route entry at any time in the routing table), the large number of routing and forwarding tasks, and secondly, the backbone network node does not move, Then the node also does not have the problem of insufficient power supply, you can directly use fixed power supply to power, so the backbone node of these devices in the hardware and software selection, do not consider power problems, performance without limit; Again, the backbone network node does not move, the entire mesh network topology will be stable, mesh network reliability, The reality of the application is also available. Here is a diagram of the topology of the Adhoc network and the wireless mesh network to show the difference:

(a) Adhoc network

It can be seen that the nodes of the Adhoc network are completely equal, without backbone network, distributed state.

(b) Wireless mesh network

There is no essential difference between wireless mesh network and Adhoc network, which is to manage nodes by self-organization form, but the backbone network appears in wireless mesh network, the biggest network is backbone network.

My task is to use the ARM Development Board +linux system to "make" the backbone node of the wireless mesh network. The concrete construction process of the node, (b) is introduced.

Building wireless mesh networks using ARM development boards (i)