Why Text Messages Are Limited To 160 Characters

The LA Times has a story about Friedhelm Hillebrand, one of the communications researchers behind efforts to standardize various cell phone technologies. In particular, he worked out the 160 character limit for text messages. "Hillebrand sat at his typewriter, tapping out random sentences and questions on a sheet of paper. As he went along, Hillebrand counted the number of letters, numbers, punctuation marks and spaces on the page. Each blurb ran on for a line or two and nearly always clocked in under 160 characters. That became Hillebrand's magic number ... Looking for a data pipeline that would fit these micro messages, Hillebrand came up with the idea to harness a secondary radio channel that already existed on mobile networks. This smaller data lane had been used only to alert a cellphone about reception strength and to supply it with bits of information regarding incoming calls. ... Initially, Hillebrand's team could fit only 128 characters into that space, but that didn't seem like nearly enough. With a little tweaking and a decision to cut down the set of possible letters, numbers and symbols that the system could represent, they squeezed out room for another 32 characters.

Comments

I'll Be Damned

[eldavojohn]

And all this time I was almost certain that it was based on sound scientific research proving that 160 characters was the maximum amount of text a cell phone user could read before completely losing interest.

Re:I'll Be Damned

[Anonymous Coward]

Technically, it was the largest number that Hillebrand could count to in his mind before losing track.

Re:I'll Be Damned

[JeffSpudrinski]

The few times I've tried messaging from my cell phone, my thumbs cramp after about 50 characters, so the "limitation" never affects me.

Re:I'll Be Damned

[Red Flayer]

tl;dr

Re:I'll Be Damned

[Anonymous Coward]

And all this time I was almost certain that it was based on sound scientific research proving that 160 characters was the maximum amount of text a cell phone us...

I totally lost interest past that.

Re:I'll Be Damned

[FatdogHaiku]

If you make it into a MySpace style survey (mix in questions about favorite color and second letter of last name, etc.), not only will they answer you, they will forward it to everyone they know... and most of those people will also reply.

Re:BINGO!

[plover]

I wonder what type of DRM you can put on a punch card

You could print shadowed boxes that look like punched holes, that way if someone puts them on a photocopier or in a fax machine it'll look like the holes are there, but a real reader wouldn't see them.

You could put transparent tape over a few of the holes. The common cheap, at-home card readers which read cards optically to save a few bucks will not notice the transparent window. But the Big Iron IBM punch card readers that use real steel fingers to read the holes will simply ignore the taped-over holes.

Along the same vein, you could put red colored tape over the holes, and build the Genuine IBM readers with blue laser readers instead of red. They'll be transparent to the at-home punch-card copy machines that use cheap red lasers, but opaque to the blue frequencies.

Or you could punch some extra or oversized holes in some non-standard locations, like the old half-tracks on the floppy disks. Only official IBM punch machines would be able to accurately copy them.

I got it! Embed a smart chip in the corner of each JCL card, with some cryptographic verification or signature algorithm. As each punch card travels through the system, electrical contacts would verify the authenticity of the card. 4096-bit RSA on the chip ought to do the trick nicely.