Patras wireless metropolitan network

Patras Wireless Metropolitan Network (PWMN) is a free (as air), open wifi network community of individuals who all share the same hobby; building and managing wireless networks. Currently PWMN is the dominant wireless network community in Patras, Greece. It has about 80 active members (March 2008) who are the individual node owners of this metropolitan area network and spans over 5 Greek provinces (Achaia, Ileia, Etoloakarnania, Fokida, Corinthia) with links up to 65km. It came into existence after the merging of the two previous dominant wireless networks in Patras, namely Patras Wireless Network and SPN in early 2007. It is a non-profit organization which aims to explore network technologies (basically wireless 802.11) and new computer associated technologies in general.

The Vision

A shared vision of most PWMN members is what we call the open source internet which is a global computer network where its users are at the same time the ISPs, contribute to its development (hardware/software) and is free for everyone to access. The concept is similar to the one followed in the open source software context. The first steps towards this vision is to connect all the already well-established wireless community networks of all the major Greek cities together, thus forming probably the largest (at least area-wise)wifi network ever!.


Project history

PWMN is relatively new (early 2007) but its roots trace back to 2001 when the first wireless network community in Greece was formed: Patras Wireless Network(PWN). The second part of PWMN comes from a totally independent wireless community network, SPN which was being deployed since 2004 in parallel with PWN. In 2006 SPN boasted a faster backbone than PWN, more enthusiastic active members, and a more open/distributed management than the older, more conservative and centrally-managed PWN. In early 2007, most PWN and SPN members decided to overcome their differences and form a totally new network community with members from both networks, following the distributed management system used by SPN, which proved to work better in the community context. Since then PWMN has grown and is now better than ever.


Location

PWMN is, in the most part, based in the city of Patras and its suburbs. Patras' shape and geophysical characteristics (mainly hills) has made it quite difficult to establish wireless links around the whole city. This is because the links require Line of sight. Despite the difficulties, PMWN boasts double or triple-way backbones which together with the dynamic routing protocol used (OSPF), makes the whole network very robust and very fast. Recently, following the shared vision, the network has started to cover a much wider area, aiming at linking all of mainland Greece. This is not a trivial task since most cities are separated by sea, big mountains and large distances. So far, PWMN has managed to establish long distance links up to:
Kyllini in Ileia (straight 65km link from Aroe in Patras) which will shortly be linked with Wireless Amateur Network of Amaliada (WANA)
Nafpaktos in Etoloakarnania (straight 20km from Patras)
Skaloma in Fokida (20km link through Kamares which is linked to Nafpaktos through a 20km link)
Ligia in Derveni, Corinthia (62km link to Nafpaktos)
40km Link to Arakynthos a mountain in Etoloakarnania (the actual name of the place is ellinika) tested, which will later link to WiRAN the Wireless network of Agrinio


Design

The hardware used in PWMN is of-the-shelf 802.11a, 802.11b Wireless devices which operate in 5.4 GHz and 2.4 GHz license-free ISM bands. The actual Computer Hardware used for the Wireless routers can vary from simple Wireless access point to small Single-board computer(SBCs) up to conventional PCs.

The Routing protocol currently used (March 2008) is OSPF, a dynamic routing protocol using a distance vector algorithm. Since the actual network deployment gets more and more meshed with multiple paths from one node to another, the network could benefit by a smarter dynamic routing protocol such as OLSR which is already in use in parts of Athens Wireless Metropolitan Network.

PWMN relies mainly on open source software, and Linux is used to support many PMWN services.

The services used throughout PWMN cover a wide range. One of the main services is the PWMN forum which is the main place for open discussions concerning the network. The PWMN wiki projectaims at creating a big knowledge base for all the challenging aspects of wireless networking. As such it contains various Guides, Tutorials, Member's own designs and even networking equipment reviews. PWMN relies heavily on the WiND project to create a map of the wireless nodes and links using actual terrain info. PWMN users prefer to use IRC for their instant messaging needs; the IRC servers throughout the network are connected to a broader network of IRC servers (HWN:Hellenic Wireless Network) which serve all of the Greek Wireless Communities. There are plenty more services like Game Server, File sharing, VOIP, VPN, DNS, Network monitoring and plenty others.