xarxa sensefils cooperativa

community wifi mesh internet provider in barcelona.

website: http://xsf-coop.net

Barcelona, there were wifi nets that were spread out, too atomised to work. They looked to make an ISP and free network on the scale of the city. They made a small coop working with a legally declared as an ISP. They have the contract and pay the bandwidth from a data centre they are connected to. They have a deal with a local establish ISP to buy bandwidth together to make it more affordable. THere is an antenna on top of the data center building, and their super nodes are connected to the antenna.

The longest distance is connection is ??, at 5ghz (802.11a).

The first supernode is in a commercial communication tower, where they rent a space. The other supernode is located on the roof of a neighbor living on the top of a hill. It is 12 meters tall, they just built it recently. They want to develop this one more, because they don't have to pay for it.

The connection is then spread with sector anntenna to cover the city (60 degree arc). There are some points in the city using 11a, they cover those neighbourhoods. Example, 11a connected 11g to serve the neighbourhood, giving connection wired as well?? Some of these clients act as AP for other clients. The nodes are not personal computers, they provide network for an entire community in a building, 1-4 neighbours up to 9 to 10. They share cost and bandwidth amongst themselves. There are 40 neighbour communities at the moment covering 90 flats including squats and social centres.

This was difficult to put into action, but they make a difference between internal traffic for the 11g net and the external internet. They want a free network between the internal clients all over the city.

There is list of computers which have access to the whole internet. There is also open access, and then computers not on the internet list can access freely the barelona network. They are still developing this part of the network, but there is already content that is just for the network.

It is the same network, but only the people who pay to be part of the cooperative have access to the gateway out to the internet. They have only set up this system of controlled access to the gateway a few months ago.

They have some high antenna, so it could be extended to other cities, but this is not the intention at the moment.

When people pay financially for access to the internet, they also support the extension of the local network. Part of the fees goes to pay for people to keep reliable service to the internet, and giving an emergency number for problems with the connection. 2 people work on the technical side, one of them an antenna specialist, he constructed the 12 meter tower.

The cooperative pays for the bandwidth and supernodes, but people then pay for their own access points.

With 70 communitites they think they will be financially sustainable, and able to spend more money/time/resources on the barcelona local network.

In a city like Barcelona 11b/g does not reach very far. So they are trying to make connection to clients directly with 11a. Although 11a is more expensive, it is cheaper when on a larger scale (longer distance?).

For the mesh system to work they need more density of nodes, they are or want to experiment with this on a small level. At the moment it is more realistic to begin with a few supernodes (? guess so)

They have an assembly of community members who decide the larger issues. The technical day to day decisions are made by the technical workers.

One big problem they have is that they do not know of anyone doing anything similar. The technical problem with internet and non-internet was something they had not met others doing.


Q: do people have public IP addresses? A: the people who want can have a public IP address. They can run a server accessible to the internet

Q: how much bandwidth do you use? A: the contract with the data center is shared with the ISPs, at the moment between ISP and the wifi there are 5-6 Mbits symetric the wifi pays for about 2.5 Mbits of usage.

Q: how many people? A: as there can be a few people in a flat or many in a squat there are between 200-300 people served, probably 300.

Q: why did you feel the need to limit access to the internet, would it cost too much? A: if there was no one paying we could not guarantee access to the internet, we need some people to pay. There are people using the network who are activists, but also people without affinity to social movements who are not happy with the telephone company

Q: could you give low priority/speed access to the internet to those who don't pay? A: it is a possibilty we give unused bandwidth to those who don't pay

Problems can be related to the cheap 11g equipment. If people don't have an interest in the technology they don't know about why something isn't connected. They have others reliant on the connection. They are working on automatic ways of checking.

They are using Linksys. These may have difficulty with high traffic. For super-nodes they are using routers linking 11a and 11b - hardware?

People from seattle wifi have started a company that builds and sells small AP ~$200, these are pretty solid and super reliable. Running a stripped down linux distro.

Q: Are they investigating other technologies, like WiMAX? A: We're working more and more with 11a because there is less interference. If other technologies work better, perhaps we'll use it in the future. We have a lot of communuities, so if we change we will have a lot of work to do.

STAMP: MeetingNotes/XarxaSensefilsCooperativa (dernière édition le 2008-12-19 19:00:03 par anonyme)