Why Text Messages Are Only 160 Characters


The LA Times recently delved into the history of the text message -- specifically, why text messages are limited to 160 characters. The answer starts in Germany, in 1985, when researcher Friedhelm Hillebrand was thinking about adding a text messaging service to the nascent cellular telephone system. He typed various statements, questions, and brief messages on a typewriter. When he reviewed what he had typed, he saw a pattern: they all fit within 160 characters. Perhaps if he had been a more verbose writer, we'd have longer text messages today -- but no, Hillebrand was convinced that his short messages were just the right length. As the LA Times recounts it: "This is perfectly sufficient," he recalled thinking during that epiphany of 1985, when he was 45 years old. "Perfectly sufficient." Hillebrand started looking for a way to fit these "short messages" into the existing cell phone network...and the rest is history.

Read a bit more about the early days of SMS (Short Messaging Service):

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. Still, his committee wondered, would the 160-character maximum be enough space to prove a useful form of communication? Having zero market research, they based their initial assumptions on two "convincing arguments," Hillebrand said. For one, they found that postcards often contained fewer than 150 characters. Second, they analyzed a set of messages sent through Telex, a then-prevalent telegraphy network for business professionals. Despite not having a technical limitation, Hillebrand said, Telex transmissions were usually about the same length as postcards.

So did Hillebrand get rich from his invention? Not exactly. He's still working in mobile communications, and recently wrote a book (with a >$200 sticker price!) about his work on early cell phone networks.

(Photo courtesy of Flickr user semarr, used via Creative Commons license.)