This is possible because there are no expenses of any importance, as the volunteers who build and maintain the network do not receive any payment for their contribution and the materials needed were donated.
In the city center, however, on most places a laptop antenna is enough to access the network.
Wireless Leiden has been called one of the most advanced community Wi-Fi networks in the world.
[2] Wireless Leiden was published as a case study of a Wi-Fi based community network in 2010.
[1] Stefan Verhaegh of the University of Twente analyzed the "Wireless Leiden" case in his 2010 PhD thesis.