Introduction

Current computer networks generally rely on a permanent, fixed and largely wired infrastructure which is owned and often operated by large entities such as telecom operators. A relatively new and emerging technology is wireless Ethernet, or wireless networking using the IEEE 802.11 standard. This standard encompasses the lower layers of the OSI model for transport of data as Ethernet frames using a spread spectrum based radio link.

This opens the possibility of building a network without having the problems and the cost associated with putting some sort of physical transmission medium in the ground. Instead, antennas can be used to send and receive the data using radio waves through free air.

Because of the relative simplicity of the currently available commodity hardware that uses 802.11 technology, it is relatively easy to build a local wireless community network in a town. Using this network people can share resources with each other. Examples are sharing sound or video files with the local museums, or having data (text, images, video, audio files) provided by the local government on-line. Furthermore, the network can connect to the Internet providing a low cost way of crossing the last mile to the user at high bandwidth.

In Leiden, the Netherlands, a foundation has been established by a number of knowledgeable volunteers with the intention to build a network operated and owned by a community of users, not by big entities such as telcos or Internet Service Providers (ISPs). This essentially free network infrastructure can be used by anyone present in the service area for running his or her own application. On the client platform only an industry standard IEEE 802.11b interface and a probably small antenna is needed. Usage of the infrastructure is not "another monthly bill", but will be free, after a one time up-front investment in equipment.