40 Years After Carterphone Ended AT&T Equipment Monopoly

fm6 writes "Wednesday was the 40th anniversary of the Carterfone Decision which brought to an end AT&T's monopoly on telephone terminal equipment. Ars Technica has an opinionated but informative backgrounder on this landmark, which pretty much created the telecommunications world as we currently know it."

Comments

how carter won

[trb]

If I recall, this is how Carter won that suit. AT&T always claimed that they were concerned that if competitors connected their hardware to the AT&T network that they might damage the network with badly coupled electrical loads, see http://en.wikipedia.org/wiki/Ringer_equivalence_number

Carterphone had a device where the handset sat in the cradle of their device, it worked in a similar manner to the later acoustically coupled modems, see: http://en.wikipedia.org/wiki/Acoustic_coupler

So there was no electrical connection (coupling) between the Carter device and the phone. The device had a cradle that the handset sat in, coupling the mic and the speaker. The AT&T lawyers said, well, your device is touching our handset. So Carter lifted the handset an inch out of the coupler, and said, is this too close? The AT&T lawyer said yes. So Carter carried his device across the room and said is this too close? The lawyer said no. Then Carter moved closer and closer, and AT&T's defense crumbled.