My article on municipal Wi-Fi appears in the next issue of the Economist, online now: Those who read this site regularly know my take on the matter, which is that overpromising of indoor Wi-Fi coverage by some firms and cities (not most, thankfully); an expectation of much higher subscriber numbers; underbuilding of the network in early phases based on overoptimistic coverage estimates; an rush to the bottom to provide no-cost networks to city with revenue chasing the subscribers who never arrived; and a lack of plans by most cities about what, in particular, to do with the networks that were being built has led to the current implosion.

While some folks in the industry have tried to persuade me that public safety money won't drive the future of metro networks, I find that as I talk to cities and counties--often dozens a month through casual email or more in-depth conversations--that unwiring public safety is a high priority. The 4.9 GHz band is really taking off, and the availability of equipment that's starting to become commodity priced for 4.9 GHz receivers and adapters makes it a good move for cities and counties from typically proprietary gear running on narrow slivers of bandwidth. (That's the whole Sprint Nextel spectrum reallocation nonsense still in play.) Not all communications are suited for 4.9 GHz, but a lot of critical ones work quite well, including video and high-bandwidth transfers from officers and workers in the field.

Combine public safety money with municipal needs as they better articulate them, and you have a business plan in which a service provider's first and foremost set of numbers deals with providing a fixed set of services at a given rate of profit. Adding service to the public for mobile and, as 802.11n starts to penetrate, some indoor access becomes an incremental revenue source above the baseline that the provider establishes to build and operate the networks.

As Chuck Haas of MetroFi point out to me, if a city wants to have a 4.9 GHz public safety network, there can be only one client and one line of revenue: the city. Thus, 4.9 GHz networks must be fully funded with the profit motive in mind. That provides the base on which 2.4 GHz networks could be built.