day 1: 04/04/07
wireless community networks
Most wireless community network projects are coordinated by citywide user groups who freely share information and help using the Internet. They often spring up as a grassroots movement offering free, anonymous Internet access to anyone with WiFi capability.
Many of these community networks are run on a voluntary basis and can be compared to other voluntary groups focussed around local issues. Like other voluntary groups they have sometimes found their greatest challenges are not technical (e.g. developing affordable internet access in a local area) but social; encouraging and sustaining volunteer input, a critical mass of users, and devising a sustainable organisational model. Some groups have splintered as individual participants follow their own goals or found it difficult to maintain a user base when large corporate internet service suppliers have reduced the price of broadband connectivity and increased availability.
Wireless community networks or wireless community projects are the largely hobbyist-led development of interlinked computer networks using wireless LAN technologies, taking advantage of the recent development of cheap, standardised 802.11b (Wi-Fi) devices to build growing clusters (group of the same or similar elements gathered) of linked, citywide networks, or in rural areas where conventional DSL services are unavailable. Some are being used to link to the wider Internet, particularly where individuals can obtain unmetered internet connections such as ADSL and/or cable modem at fixed costs and share them with friends. Where such access is unavailable or expensive, they can act as a low-cost partial alternative, as the only cost is the fixed cost of the equipment.
As of mid-2005, wireless community networks have become increasingly popular and exist throughout many cities. Such networks have a distributed rather than a tree-like topography and have the potential to replace the congested and vulnerable backbones of the wired internet in most places.
These projects are in many senses an evolution of amateur radio, and more specifically packet radio, as well as an outgrowth of the free software community (which in itself substantially overlaps with amateur radio), and share their freewheeling, experimental, adaptable culture. The key to using standard wireless networking devices designed for short-range use for multi-kilometre linkups is the use of high-gain antennas. Commercially-available examples are relatively expensive and not that readily available, so much experimentation has gone into homebuilt antenna construction.
Mesh networking is a way to route data, voice and instructions between nodes. It allows for continuous connections and reconfiguration around broken or blocked paths by “hopping” from node to node until the destination is reached. A mesh network whose nodes are all connected to each other is a fully connected network. Mesh networks differ from other networks in that the component parts can all connect to each other via multiple hops, and they generally are not mobile.
Mesh networks are self-healing: the network can still operate even when a node breaks down or a connection goes bad. As a result, a very reliable network is formed. This concept is applicable to wireless networks, wired networks, and software interaction.
CZFree.Net is an free wireless network in Prague based on open standards. It uses the IEEE 802.11b protocol to connect nodes around the city, creating a community run network that costs virtually nothing to maintain.