Patras Wireless Network
Encyclopedia
Patras
Wireless Network (PWN) is, historically, the first city-wide, wireless community network
in Greece
. It is run and maintained by the users of the network. It serves 150 people, covering a mountainous area of 60 km².
Wireless Access Point
. The AP was installed on a TV tower in Aroe which has a vantage point of the whole city of Patras
. The first private, city-wide wireless connection in Greece
was established then.
Claim to fame for PWN was that members on the network solved the hidden node problem
, by designing and implementing the Wireless Central Coordinated Protocol (WiCCP), a protocol booster for 802.11b DCF based wireless networks, that provides cyclic token-passing medium access, and scheduled allocation of the available network resources, eliminating the hidden node problem
.
. The main effort of the founders was to evaluate the performance of the TCP/IP protocol suite, over error-prone wireless links, while applying several protocol boosters at the link layer.
. Later on, as the network became more stable, the founders decided they could extend the functionality to network themselves and some friends together, overcoming the inability of the state-run telecommunications company of Greece
, OTE
, to deliver high-speed internet access in the city of Patras.
, located on the TV tower of the Greek television Network, in Aroe. That created a huge problem during night-time. Night time is mainly the heavy-usage hours of the network. So, the following rules where put in place, in order to accommodate smooth usage by all users:
is built around a hill, Alsos Hill (100 m alt.), the highest point in the city. It is also the location of the central Access Point and the reason for the uniqueness in the network design. The network started with a "star" topology. All clients or access point were connected through the main Access Point in Aroe hill. This topology is severely flawed, mainly due to the hidden node problem
, so the network moved to a bus-ring topology, providing more reliability to the users.
and using some form of bandwidth
throttle in order to distribute their bandwidth on the network.
.
Furthermore, other community members started project WiFiAdmin. Wifiadmin is a PHP web environment for the administration of the open source (*nix) wifi node. It provides an interface for wireless tools and other common wifi linux/BSD drivers, while keeping statistical data on the node. A research paper presenting WiFiAdmin has been published in IEEE international conference.
Hardware projects include the guide on the rooftop Access Point. It's an attempt to write a guide on how to safely power a rooftop Wireless Access Point-node from a long distance (over 500 m) and turn it into a robust all-weather installation, that can stay unattended for days on end.
Currently, the network members are also trying to put together a representative team that will get in contact with the city councel of Patras
or the University of Patras
in order to obtain some form of connectivity with the rest of the world.
Patras
Patras , ) is Greece's third largest urban area and the regional capital of West Greece, located in northern Peloponnese, 215 kilometers west of Athens...
Wireless Network (PWN) is, historically, the first city-wide, wireless community network
Wireless community network
Wireless community networks or wireless community projects are the organizations that attempt to take a grassroots approach to providing a viable alternative to municipal wireless networks for consumers....
in Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
. It is run and maintained by the users of the network. It serves 150 people, covering a mountainous area of 60 km².
Introduction
Patras Wireless Network was established in 2001 after a company of 4 friends put together the money to purchase an OrinocoOrinoco
The Orinoco is one of the longest rivers in South America at . Its drainage basin, sometimes called the Orinoquia, covers , with 76.3% of it in Venezuela and the remainder in Colombia...
Wireless Access Point
Wireless access point
In computer networking, a wireless access point is a device that allows wireless devices to connect to a wired network using Wi-Fi, Bluetooth or related standards...
. The AP was installed on a TV tower in Aroe which has a vantage point of the whole city of Patras
Patras
Patras , ) is Greece's third largest urban area and the regional capital of West Greece, located in northern Peloponnese, 215 kilometers west of Athens...
. The first private, city-wide wireless connection in Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
was established then.
Claim to fame for PWN was that members on the network solved the hidden node problem
Hidden node problem
In wireless networking, the hidden node problem or hidden terminal problem occurs when a node is visible from a wireless access point , but not from other nodes communicating with said AP. This leads to difficulties in media access control....
, by designing and implementing the Wireless Central Coordinated Protocol (WiCCP), a protocol booster for 802.11b DCF based wireless networks, that provides cyclic token-passing medium access, and scheduled allocation of the available network resources, eliminating the hidden node problem
Hidden node problem
In wireless networking, the hidden node problem or hidden terminal problem occurs when a node is visible from a wireless access point , but not from other nodes communicating with said AP. This leads to difficulties in media access control....
.
Mission
The original mission of PWN was mostly experimental, focused on using off-the-shelf wireless devices or PCs operating under Linux, to establish 802.11b links over the city of PatrasPatras
Patras , ) is Greece's third largest urban area and the regional capital of West Greece, located in northern Peloponnese, 215 kilometers west of Athens...
. The main effort of the founders was to evaluate the performance of the TCP/IP protocol suite, over error-prone wireless links, while applying several protocol boosters at the link layer.
History
Reasons for deployment
The initial reason for the network deployment was to test the 802.11b protocol in the rural environment of PatrasPatras
Patras , ) is Greece's third largest urban area and the regional capital of West Greece, located in northern Peloponnese, 215 kilometers west of Athens...
. Later on, as the network became more stable, the founders decided they could extend the functionality to network themselves and some friends together, overcoming the inability of the state-run telecommunications company of Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
, OTE
OTE
Hellenic Telecommunications Organization S.A. , usually known by its Greek initials OTE, is the dominant telecommunications provider in Greece. Formerly a state-owned monopoly, OTE was part-privatized in 1998 and is now listed on the Athens and New York Stock Exchanges...
, to deliver high-speed internet access in the city of Patras.
Form of management
There is no "management" per se, of the network. The state of the network is supposed to be a free-flow, anarchical state, where ordinary citizens are not bound by the short-comings of the Greek telecom company and are able to organise something on their own, without asking or wanting private or state assistance and sponsoring.Funding and Equipment
Funding is mostly provided by the users of the network, by either rallying up money for purchasing of equipment or by equipment donation.Rules of Operation
In the early days of operation of the network, traffic between the two large segments that comprised the network, went though a single, central wireless access pointWireless access point
In computer networking, a wireless access point is a device that allows wireless devices to connect to a wired network using Wi-Fi, Bluetooth or related standards...
, located on the TV tower of the Greek television Network, in Aroe. That created a huge problem during night-time. Night time is mainly the heavy-usage hours of the network. So, the following rules where put in place, in order to accommodate smooth usage by all users:
- Every day, 10 p.m. to 2 a.m., was designated as "gaming hours". All file transfers must stop between those hours.
- File transfers must be limited to 50 kB/s
- Violators of the above policies, will be given a 24 hour ban from the network
- Repeat violators will be permanently banned.
Architecture and topology
The city of PatrasPatras
Patras , ) is Greece's third largest urban area and the regional capital of West Greece, located in northern Peloponnese, 215 kilometers west of Athens...
is built around a hill, Alsos Hill (100 m alt.), the highest point in the city. It is also the location of the central Access Point and the reason for the uniqueness in the network design. The network started with a "star" topology. All clients or access point were connected through the main Access Point in Aroe hill. This topology is severely flawed, mainly due to the hidden node problem
Hidden node problem
In wireless networking, the hidden node problem or hidden terminal problem occurs when a node is visible from a wireless access point , but not from other nodes communicating with said AP. This leads to difficulties in media access control....
, so the network moved to a bus-ring topology, providing more reliability to the users.
Connection to the Outer World
The network does not have an official connection to the global internet. Some members of the network share their aDSL lines by setting up HTTP proxiesProxy server
In computer networks, a proxy server is a server that acts as an intermediary for requests from clients seeking resources from other servers. A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource available from a different server...
and using some form of bandwidth
Bandwidth (computing)
In computer networking and computer science, bandwidth, network bandwidth, data bandwidth, or digital bandwidth is a measure of available or consumed data communication resources expressed in bits/second or multiples of it .Note that in textbooks on wireless communications, modem data transmission,...
throttle in order to distribute their bandwidth on the network.
Projects
PatrasWireless is a very active network. The community has developed various hardware or software projects. One of the first and most promising projects is the design and implementation of the Wireless Central Coordinated Protocol (WiCCP), a protocol booster for 802.11b DCF based wireless networks, that provides cyclic token-passing medium access, and scheduled allocation of the available network resources, eliminating the hidden node problemHidden node problem
In wireless networking, the hidden node problem or hidden terminal problem occurs when a node is visible from a wireless access point , but not from other nodes communicating with said AP. This leads to difficulties in media access control....
.
Furthermore, other community members started project WiFiAdmin. Wifiadmin is a PHP web environment for the administration of the open source (*nix) wifi node. It provides an interface for wireless tools and other common wifi linux/BSD drivers, while keeping statistical data on the node. A research paper presenting WiFiAdmin has been published in IEEE international conference.
Hardware projects include the guide on the rooftop Access Point. It's an attempt to write a guide on how to safely power a rooftop Wireless Access Point-node from a long distance (over 500 m) and turn it into a robust all-weather installation, that can stay unattended for days on end.
Future plans
Future plans include increasing the availability of the network, by interconnecting the access points in a mesh manner, in order to allow for truly dynamic routing between each access point.Currently, the network members are also trying to put together a representative team that will get in contact with the city councel of Patras
Patras
Patras , ) is Greece's third largest urban area and the regional capital of West Greece, located in northern Peloponnese, 215 kilometers west of Athens...
or the University of Patras
University of Patras
University of Patras is a university established in 1964 in Patras, Greece. Initially housed in the city centre, the university's campus is now located in the adjacent municipality of Rio...
in order to obtain some form of connectivity with the rest of the world.
See also
- Wireless community networkWireless community networkWireless community networks or wireless community projects are the organizations that attempt to take a grassroots approach to providing a viable alternative to municipal wireless networks for consumers....
- Athens Wireless Metropolitan NetworkAthens Wireless Metropolitan NetworkStarted in 2002 in Athens Greece, Athens Wireless Metropolitan Network is a grassroots wireless community, taking advantage of new, state of the art wireless technologies, to connect people and services. The network comprises 1120 backbone nodes and more than 2900 client computers connect to it...
- Wireless Thessaloniki (WThess) NetworkWireless ThessalonikiWireless Thessaloniki is an experimental wireless community network growing in the air of Thessaloniki, Greece. It is one of the first wireless networks deployed in the city....
- Heraklion Student Wireless NetworkHeraklion Student Wireless NetworkHeraklion Student Wireless Network is a city-wide, non-profit wireless community network in Heraklion, Crete. It is run and maintained by the users of the network, who at the beginning of the network's existence were exclusively members of the academic community of the University of Crete...
- Ioannina Wireless NetworkIoannina Wireless NetworkIoannina Wireless Network is a non-profit wireless network based in Ioannina, Greece. Its primary goal is to interconnect interested parties using wireless technology , promoting the free diffusion of knowledge and the spirit of cooperation...
- Patras wireless metropolitan networkPatras wireless metropolitan networkPatras Wireless Metropolitan Network is a free , 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...