Beginning in about 1910, telegraph companies began to use telex, a rotary dialing system for routing telegraph calls, much like that used in telephone networks.Telex initially ran at the amazing signaling speed of 45.5 bits per second (bps) and, later, at 50 bps, or 66 words per minute (wpm). At that signaling rate, one analog voice grade channel could support 24 or 25 telex transmissions through frequency division multiplexing (FDM). In 1958,Western Union introduced its Telex