FAQ

This is the mostly asked question ;-)

The answer is: first find out if a Wireless Leiden node is available in your area. Look out of your window, if you can see the node (access antenna) or if you live close then there is a good chance. Also the location (height) of your own antenna is important.

At the walk-in consultancy hour or via the users mailinglist you can discuss your situation with volunteers and other users of Wireless Leiden. They often have a good idea whether a connection is or is not possible at your location.

You can only be sure by measuring the signal strength or trying out. Maybe you can find a volunteer who wants to help out at the consultancy hour.

Yes, you can get those programs to work by defining the proxy (if you use a proxy; this is no longer necessary since 2012) in your settings. Which proxy works best depends on your location, so try different settings. If you use linux you can define a system proxy by the statement
export http_proxy="http://proxy...wleiden.net:3128".

No.

The user has to obtain, install and maintain his own equipment . The basic WiFi networking gear can be obtained from any computer store. Antennas, cables, connectors are a.o. for sale at

• Graficall, Bielsenstraat 1-B, 2316 KA Leiden, tel.nr. 071-5221014
• Micromax, Van Assendelftstraat 8, 2342AS Oegstgeest, tel. nr 071-5190760

Wireless Leiden is not an Internetprovider!

We only facilitate a local, wireless network that interconnects local users. The use of the local network is free without restrictions. If users of Wireless Leiden want to share their internet connection they can do so. Note that not all providers allow this, check your contract!

There are a number of sponsored internet connections available on the network via 'proxies' (gateways) that can be used by anybody. Since 2012 it is also possible to connect to our network without defining a proxy. The capacity is limited and only webbrowsing is possible (so called 'port 80' and 'port 443' traffic; or 'http' and 'https'). For e-mail you need to use webmail (such as gmail, yahoo-mail, outlook.com webmail, etc.) or use the webmail portal to your e-mail account. For MSN or Skype you have to define the proxy settings in these programs, if you use our proxies.

Yes, everybody can make a contribution to Wireless Leiden. There are a lot of things that need to be doen and absolutely not only for computer geeks (although they are always very welcome!).

Who is a handy do-it-yourself person can help with building and maintenance of antenna installations (nodes).

Also consider:

• organisational and adminstrative work,
• coaching and coordination volunteer activities,
• maintaining the website, adding content, write documentation,
• measuring coverage (automatically collecting local data)
• give presentations, manning of infostands
• finding sponsors,
• coaching students,
• helping users to connect and/or set up their pc,
• make a roof top available,
• (partially) share your internet connection (depending on the contract with your provider).

Come and see us at the walk-in consultancy hour or send an e-mail to the users mailing list. Furthermore we depend for the financing of the network on voluntary contributions. You can help building and maintaining the network by making a donation to our banking account NL08RABO0138456062 t.n.v. Stg. Wireless Leiden.

Information is available on the Internet:

• this website
• the "wiki" site: http://wiki.wirelessleiden.nl
• the collection of various documents, fotos and software: http://svn.wirelessleiden.nl/svn
• the mailing lists: http://lijst.wirelessleiden.nl
• the web folder: http://webfolder.wirelessleiden.nl

And the 'walk in consultancy hour' (usually on Wednesday night, check this website).

Wireless Leiden is not an internet provider. If you just want to use the Internet and you can get and afford your own dedicated internet connection, we recommend to do so. That way the free, wireless Internet via Wireless Leiden remains availalbe for those who can not get a fixed connection, those who need a connection termporarily (e.g. when moving house or in case of a problem with their connection), those who are visiting (tourists, business visitors) and for use 'on the street'.

An own connection will usually also be faster and more reliable and you can use all internet services, not just web browsing and web mail.

The use of the network is free (gratis), we do not ask a financial contribution. The (one-time) equipment costs (if you use our network at home) depends very much on the way you decide to make the connection.

• In the simplest situation you can use your wifi-enabled laptop, phone or tablet without any additional equipment, if the built-in antenna is good enough. You can test this simply by trying to connect.
• However, often you will need an outside antenna or usb-adapter. A usb-adapter with a 5 meter long cable costs approximately E 25.
• To provide a desktop PC with a WiFi-card with antenna cable and outside antenna will cost roughly E 100 - 200, depending on e.g. the length of the cable, the antenna type and the construction.
• A prefabricated, ready to use solution with built-in radio and antenna (for instance a Ubiquity Nanostation) costs about E 80.

We try to keep operational costs as low as possible by the use of open source (free) software and inexpensive equipment, to cooperate with businesses and organisations who e.g. provide access to roof tops throughout the city and by working with unpaid volunteers. The costs of the network are therefore mainly the purchase and maintenance of the hardware. We do not receive subsidies. For our financing we are fully dependent on sponsoring and donations.

If you want to support us financially: our bank account is nr. NL08RABO0138456062, Stg. Wireless Leiden at Rabobank.

Practice shows that distances of several kilometers are quite feasible.

The maximum distance depends on a lot of variables: the antennas used, the height of the antennas, the area in between, the nature of the surroundings (e.g. presence of metal). In wooded areas the transmittance is effectively reduced. As a rule of thumb you need a free line-of-sight between the two antennas, which means that you should be able to actually see the antenne of the access point that you want to connect to. Note that also the user has to stick to the legal maximum power of 100 mW, power amplifiers are illegal and a nuisance for your neighbourhood!

Wireless Leiden aims at a distance between nodes of about 800 meter. The distance of the average user to an accesspoint will therefore be about 400 meter. The bandwith at that distance will be close to the nominal bandwidth (i.e. 11 Mpbs and effectively 4 - 5 Mbps nett data velocity); provided there is a line-of-sigtht of course and no interference from neighbouring ap's.

The data are transmitted using radio waves at a frequency of about 2,4 GHz at the nodes, where you can log is (the interlinks between nodes use a frequency of about 5 GHz). In fact there are several channels available (in Europe thirteen). However, these channels are partly overlapping. The 2,4 GHz band is a 'free' frequency, which implies that you do not need a license to use it. The only restriction is the maximum transmission power (100 mW maximum). This is very low (a thousand times less than eg. gsm or umts or the power that radio amateurs are using). This is one of the reasons that you need a 'line of sight' between sender and receiver.

The short answer is: five to ten stories is nice. The long answer:

The optimum height depends on both the desired coverage and capacity and the local density (number of nodes in a certain area).

If a node (accesspoint) is put on a high roof, it covers a large area. The coverage is good. This kind of nodes are preferrably in the starting phase of a network: large number of potential users, sufficient capacity (not many users yet). However, every accesspoint can only serve a limited number of users, otherwise the bandwidth is reduced. If the number of users in a certain area increases you have to do something about this. If there are still frequencies (channels) available you could add accesspoints at this same location, using the free channels. But the number of channels that can be used per node is limited to 3 or 4 (and some maybe used for interlinks with other nodes).

The only way out is to 're-use' the same channels by adding new nodes at a different location. Wehave to take care, however, that these additional nodes are at a relatively low location, to avoid interference.

When the network grows and the number of users increases, we need more and more nodes at ever lower locations. Ultimately this could mean that at some point in the development of the network we have to take down a node at a high location. We therefore use the high locations preferrably NOT as a public accesspoint but only for interconnections. A good example is Node SOM on the Escher tower, the highest building in Leiden.

Nope, Wireless Leiden is a non-profit Foundation, the work is done by unpaid volunteers. Wireless Leiden wants to facilitate a wireless computer network set up and maintained by a community of volunteers, businesses and organizations in the City of Leiden and surrounding municipalities. The Foundation has been established in August 2002.