I’ve always thought this (along with the notion that long distance charges are a holdover from analogue days, and also are for the most part bogus), but I always had lingering doubts, since no one else seemed to pipe up about it. Now the NYT confirms:
A text message initially travels wirelessly from a handset to the closest base-station tower and is then transferred through wired links to the digital pipes of the telephone network, and then, near its destination, converted back into a wireless signal to traverse the final leg, from tower to handset. In the wired portion of its journey, a file of such infinitesimal size is inconsequential. Srinivasan Keshav, a professor of computer science at the University of Waterloo, in Ontario, said: “Messages are small. Even though a trillion seems like a lot to carry, it isn’t.”
Perhaps the costs for the wireless portion at either end are high — spectrum is finite, after all, and carriers pay dearly for the rights to use it. But text messages are not just tiny; they are also free riders, tucked into what’s called a control channel, space reserved for operation of the wireless network.
That’s why a message is so limited in length: it must not exceed the length of the message used for internal communication between tower and handset to set up a call. The channel uses space whether or not a text message is inserted.
And why have I always thought this? Because if you know half a thing or two about how information moves from place to place, it just makes sense. The telcos take advantage of the fact that most people won’t be bothered to work this stuff out for themselves, which makes us all suckers. If I had my druthers, we’d all be using VoIP on community ad-hoc WiFi networks.
What Carriers Aren’t Eager to Tell You About Texting [NYT]
The New York Times: Text messages cost carriers virtually nothing [Boing Boing Gadgets]