Community Wireless Networks

My involvement in Community Wireless Networks came about, as a result of experiences and challenges establishing a wireless network between different office locations in order to reduce IT costs within my organisation in 2001. From this experience I realised that Community Wireless Networks offer many benefits for the broader community and other non-profit organisations like my own.

I have been a member of a group called Air Stream Wireless since 2002, and involved in the establishment of a number of key sites in the network and was voted onto the committee in 2004 holding the position of Secretary till October 2008. I have recently retired from committee due to extra commitments at work and home with the birth our second child (daughter). However, I intend to continued my participation as an active member and strong advocate for Air-Stream Wireless.

It also happens to be quite good fun making stuff and you meet many people with similar interests.

CWN Projects

Shawn Robert and Chris

Projects I have been involved at Air Stream Wireless can be seen on their website, some of these sites include:

  • Highgate Park
  • Carrick Hill
  • Bedford Park
  • MOB
  • O'Halloran Hill
  • Mawson Centre
  • Melrose Park
  • North Terrace
  • Northfield
  • Skye1,2 & 3
  • Pasadena
  • Elizabeth Water Tower
  • Parkside
  • Ridleyton

My own home wireless set-up

I run a OpenWRT customised router connected to Air-Stream network using a 25dbi grid dish antenna, the router provides multihomed services with a firewall between the Air-Stream network, my local network. It also runs a VPN between my local network and my work network which is also connected to Air Stream Wireless, providing easy access to work files, email and other services.

Another web server, which is located in the shed with the router for sharing files and information with other Air Stream Wireless members over the network.

What is a Community Wireless Network (CWN)

CWN's are a true phenomena of the 21st century and is now found in thousands of countries around the world. Although there are differences, between countries and groups most have common characteristics:

1) They are non-commercial entities established and maintained by groups of individuals.

2) They use wireless LAN to form a network that:

  • Spans across property boundaries and/or public spaces
  • Allow TCP/IP network devices and computers to communicate and share/stream data

3) They grow by:

  • Interconnecting smaller networks together to form larger networks and so overcome topographical boundaries.
  • Developing a group identity designed to focus efforts and facilitates cooperation between people of different backgrounds, skills and interests.

4) Their popularity has grown due to:

  • The relative low cost of wireless LAN equipment.
  • The ability of individuals to connect a network across property boundaries without need of a commercial carrier or special licence.
  • Public familiarity with wireless and networking/internet applications.

5) They use one or more combinations of network models:

  • WLAN – Wireless local area network
  • Mesh - Self organising adhoc wireless network
  • WAN – Wide Area Networks using wireless for user connections and backhaul
  • Hybrid – Any combination of the above including wire or fibre, in networks there are really no boundaries.

Line Of Sight (LOS), a motivator for shared networks
One of the major hurdles faced by many people setting up a wireless network over distance is the problem of establishing good LOS between two sites. Without LOS it is highly unlikely or impossible to establish a reliable network over a few hundred metres. This is because of the high frequency and low power used by most standard wireless LAN devices 802.11(a/b/g) has difficulty passing through a solid object without a significant reduction and dissipation of the signal.

With good LOS however, it is not uncommon to see links over 10kms sustained at relatively high data rates using low cost off-the-shelf equipment. But in the real world good LOS between different locations is often rare for an individual working on their own and this is the main reason many CWN groups have formed. By coordinating a group people who can share and combine their networks between those with good LOS and others without, they can overcome many of the topographical barriers that an individual would find difficult on their own.

Network Systems
To achieve the aim of building a large network and joining smaller networks together there becomes a need to develop some form of network management to allow significant numbers of nodes and users to be joined together. This is because a simple Layer 2 WLAN would not be effective and would soon congest, just as a basic wired LAN, as they do not have the ability to route or shape traffic if network congestion or failures occur.

As a result two main routing protocols have become predominantly used by CWN Groups. These are either self organizing routing systems, often termed Mesh using OLSR or Autonomous Systems similar to that used by the Internet typically BGP or in some cases OSPF.