Wireless-friendly Operating Systems
There are a number of open source operating system that provide useful tools for working with wireless networks. These are intended to be used on repurposed PCs or other networking hardware (rather than on a laptop or server) and are fine-tuned for building wireless networks. Some of these projects include:
- Freifunk. Based on the OpenWRT project, the Freifunk firmware brings easy OLSR support to MIPS-based consumer access points, such as the Linksys WRT54G / WRT54GS / WAP54G, Siemens SE505, and others. By simply flashing one of these APs with the Freifunk firmware, you can rapidly build a self-forming OLSR mesh. Freifunk is not currently available for x86 architecture machines. It is maintained by Sven Ola of the Freifunk wireless group in Berlin. You can download the firmware from freifunk.net .
- Metrix Pebble. The Pebble Linux project was started in 2002 by Terry Schmidt of the NYCwireless group. It was originally a stripped-down version of the Debian Linux distribution that included wireless, firewall, traffic management, and routing tools. Since 2004, Metrix Communication has been extending Pebble to include updated drivers, bandwidth monitoring, and a web-based configuration tool. The aim of Metrix Pebble is to provide a complete platform for wireless development. It works on x86 hardware with at least 64MB of flash or hard disk storage. You can download Metrix Pebble from metrix.net .
- m0n0wall. Based on FreeBSD, m0n0wall is a very tiny but complete fire-wall package that provides AP services. It is configured from a web interface and the entire system configuration is stored in a single XML file. Its tiny size (less than 6MB) makes it attractive for use in very small embedded systems. Its goal is to provide a secure firewall, and as such does not include userspace tools (it is not even possible to log into the machine over the network). Despite this limitation, it is a popular choice for wireless net workers, particularly those with a background in FreeBSD. You can download m0n0wall from m0n0.ch.
All of these distributions are designed to fit in machines with limited storage. If you are using a very large flash disk or hard drive, you can certainly install a more complete OS (such as Ubuntu or Debian) and use the machine as a router or access point. It will likely take a fair amount of development time to be sure all needed tools are included, without installing unnecessary packages. By using one of these projects as a starting point for building a wireless node, you will save yourself considerable time and effort.