Until deployments ramp up to near-mainstream status, the jury will likely remain out on whether Wi-Fi is an apt technology upon which to base public network services - consumer, business, municipal and public safety. After all, only when the unlicensed airwaves get heavily used and start knocking into one another will the technology\u2019s mettle really be tested.On the one hand, several municipalities have built - or are in the process of building - muni Wi-Fi mesh nets for their city workers, citizens, visitors and business users. Dayton, Ohio; Lebanon, Ore.; Mountain View, Calif.; Philadelphia; San Francisco; and Tempe, Ariz., all pop to mind.In fact, there\u2019s now even a country-wide, 1200-square-mile Wi-Fi net throughout Macedonia built on Strix mesh Wi-Fi technology, reportedly poised to serve 2 million customers.\u00a0I think most pundits would agree that the technology works. It\u2019s got multimegabit bandwidth, is initially inexpensive, scales easily as you need to grow the network, and is smart enough to route around interference - if, in fact, there\u2019s anywhere for uncongested traffic to go. At least some of the mesh vendors have engineered fast-roaming and handoff into their proprietary mesh routing protocols, enabling Wi-Fi to become a \u201cmobile\u201d technology. And, by Jove, Wi-Fi products are available, standardized, and interoperability-tested (unlike WiMAX).The fact that Wi-Fi doesn\u2019t require licensed spectrum, though, is a double-edged sword: It makes the networks fast, easy, and relatively cheap to deploy. It also makes them susceptible to innocent or deliberate interference.And since no one owns - and thus can legitimately control - the unlicensed airwaves in aggregate, no one service provider can really assure you of any particular service quality. And how does your provider troubleshoot the service and provide meaningful help desk services if your performance degrades because of outside influences?More technology might provide a partial answer. MetroFi is already offering some Wi-Fi services for $19.95 a month in Silicon Valley using SkyPilot mesh gear, which supports proprietary, WiMAX-like scheduled access technology for QoS. MetroFi CEO and co-founder Chuck Haas says the company also uses highly directional antennas to overcome interference - \u201cit\u2019s like putting blinders on\u201d the air path, he says.Using these techniques, MetroFi is able to provide guaranteed speeds of 1M-bit\/sec downlink and help desk services. This gives its fee-based structure some legs for competing against Google, which will initially offer no service guarantees with its free Wi-Fi service to become available in Mountain View sometime next spring .