I was interested, so I clicked through to find out more about the network. According to the WiFi Rail site, the network covers “Embarcadero, Montgomery Street, Powell Street, and Civic Center, and the the tubes between Civic Center and Powell Street.” That’s not quite as good as the existing area covered by the cellular network between Civic Center and Embarcadero that I have been using with my T-Mobile data subscription. (I certainly hope that the speeds are better.)
Wi-Fi Rail is asking a hefty amount ($10/day, $30/month, or $300/year). For just four stations (and the tube link between only two of them), there’s no point in buying the service a higher price than my T-Mobile HotSpot subscription. For one subscription, I would prefer to work continuously through the hour-long train ride. The cell data connection is available in the downtown corridor and in the above-ground areas of the East Bay, so it covers a bit more than half of my journey. To pry open my wallet, WiFi Rail will need to get coverage for more than half of the journey, perhaps by partnering with other hot spot networks. (They will also need a better roll-out schedule than was promised in this November 2005 San Francisco Chronicle story on the cellular network.)
The big problem for the train deployments is how to connect train riders to the Internet as they move. Typically, a train deployment will use Wi-Fi on the inside, linked up to one of a variety of backhaul technologies. The WiFi Rail web site doesn’t talk about how the train riders are linked up. My guess, given that I haven’t seen antennas in the trains, is that in-train service is provided by the APs on the platform, perhaps with antennas to get coverage down the tunnel. Spacing between the downtown stations is about half a mile, and the tunnel is nice and straight. If WiFi Rail is using the APs to provide service in tunnels, they will probably use a a fancy antenna (either a distributed antenna system or a “leaky coaxial” antenna) to get good-size coverage from a single AP.
Service is apparently free during the trial period. When I tried to sign-up, here’s what I saw when I handed over an e-mail address:
I hope the service is provided more robustly than the sign-up…