A wireless mesh network is essentially a network of a bunch of interconnected wireless routers, or nodes, which propagate traffic between users and also broadcast broadband service from nodes that are wired to the Internet. Think of it as a system of linked coffee shop hot spots where patrons at all the various coffee shops can send and receive data directly between each other’s devices, as well as surf the Web. Only you don’t have to go to a coffee shop and listen to annoying soft jazz to participate.

“Our approach is to build our own autonomous system and actually allow people to participate in the Internet rather than participating by proxy through Time Warner, Google Fiber or any other retail I.S.P.,” said Isaac Wilder, executive director of the Free Network Foundation, which within the last year has managed to construct a wireless mesh network that serves about 500 people in Kansas City, Kan.

Perhaps the largest and oldest wireless mesh network is the Athens Wireless Metropolitan Network, or A.W.M.N., in Greece, which was started in 2002 by people frustrated by the slow rollout of broadband in the city. The network now has more than 2,500 users throughout the metropolitan area and neighboring islands and offers speeds in some areas in excess of 100 megabits per second compared with the 4 to 7 megabits per second from typical residential cable and DSL connections in the United States

“It’s really fast. But it’s ended up Internet access doesn’t matter for many users because the network has its own services,” said Joseph Bonicioli, an information technology professional who is the volunteer president of the association that oversees A.W.M.N. He said the organization had its own search engines, Voice over Internet Protocol services as well as “forums, social activity and content like video.” Some developers have used the network’s intranet as a testing ground before taking their concepts and applications live on the Internet.

Community wireless mesh networks — no one tracks how many there are but it is probably in the thousands worldwide — owe their existence to relatively recent advances in wireless technology. A lot of these innovations actually come from radio astronomy, where new techniques in compression, amplification and error correction have made it possible to receive signals from distant stars, planets and probes and are just as effective, if not more so, terrestrially.