On the heels of EarthLink’s win of the Philadelphia municipal Wi-Fi network, competition for a proposed public hotspot network in San Francisco is heating up. Wireless Facilities announced today it is joining Google in its bid for the San Francisco network, challenging EarthLink and 22 other competitors for the contract.

Wireless Facilities provides design, deployment and management services for wireless networks, and if Google’s bid is successful the vendor would provide the key engineering and installation services for the citywide network. Google has yet to announce a partner to provide core Wi-Fi mesh infrastructure.

On Tuesday, Philadelphia revealed it has selected EarthLink to run its citywide Wi-Fi network. The deal effectively handed the management of the country’s largest municipally run data access network to the independent ISP, making EarthLink a prime competitor in the competition for San Francisco. EarthLink has already signaled its intent to use the Wireless Philadelphia network as a showcase network, helping it in its bids for similar contracts around the country.

EarthLink has created its own operating unit called EarthLink Municipal Networks to pursue those contracts and other opportunities in 20 to 40 major markets and numerous smaller cities, said Cole Reinwand, EarthLink director of next generation broadband, in a recent interview. He added EarthLink will approach some of those markets as a participating ISP over the city’s or another carrier’s infrastructure, but in many of them it will seek to run the network itself, like in Philadelphia.

“We’re no stranger to operating networks,” Reinwand said. “We still manage 160 remote facilities around the country. That’s down from 500, but we’re still very savvy in operating a network.”

In the Philadelphia bid, EarthLink beat out Hewlett-Packard for the prize, offering up a deal the city wasn’t likely to refuse: EarthLink is building the network. The city of Philadelphia was considering bond proposals to pay for the $10 million to $15 million network, but EarthLink’s proposal offered to finance, build and manage the network, costing the city no taxpayer dollars, EarthLink officials said.

The overall goal of the deployment will be a 135-square-mile mesh network using Tropos wireless mesh equipment. Motorola is also reportedly involved in the deal as a network equipment provider. Initially, however, EarthLink will start with a 15 square-mile proof-of-concept area, in which the ISP will launch a commercial test service for an unspecified period of time. After the testing is complete EarthLink will build out the remaining network, covering more than 80% of Philadelphia’s population.

As part of the deal, EarthLink will not only run its own ISP services over the network but also allow third-party providers to link into the network. EarthLink will charge approximately $20 a month for the service, undercutting the price of both Verizon DSL and Adelphia cable modem costs. EarthLink will offer discounted service as low as $10 a month to poorer residents that meet certain financial or hardship requirements. In an interview with Telephony last week, Reinwand said that EarthLink is planning on offering typical symmetrical speeds of 1 Mb/s over the network, making the service not only competitive with other broadband services but also opening up the possibility of other services like VoIP in future.

EarthLink is already offering on a trial basis a service called Vling, which uses a Pingtel open-source SIP client that can initiate VoIP calls over a PC. That free service coupled with the some of the capabilities of its full-fledged VoIP service TrueVoice could be extended onto the Muni network, Reinwand said. Other possible uses for the network include cellular/Wi-Fi convergence. Not only could a wireless carrier use the hotspot network to offload cellular minutes using Unlicensed Mobile Access (UMA) or VoIP over Wi-Fi technologies, the city-wide footprint could be used like a wireless wide area network, creating new opportunities for carriers to ape the cellular network using Wi-Fi, Reinwand said.

None of these possible moves is likely to please Verizon Communications, which has fought the Wireless Philadelphia project since its inception. Verizon has argued it can provide the equivalent coverage with DSL and Verizon Wireless EV-DO. Verizon went so far as to take its case to the statehouse, and a law is now on the books forbidding municipalities from launching their own broadband networks without giving the local incumbent right of refusal. Philadelphia, however, is grandfathered in.

Verizon’s actions have already led to similar proposed bands in other states, including one in Illinois, as Chicago tries to implement its own muni Wi-Fi plan. So far California has escaped RBOC pressure, and apart from San Francisco muni Wi-Fi projects have been either launched or are being awarded in several cities.