With TDMA, by contrast, each phone call took up its own slot. That limited its ability to scale, because eventually a mobile network operator would run out of slots, if too many people tried to make calls at the same time. Every network can overload, but TDMA would overload sooner with many fewer users. All in all, CDMA promised much more efficient use of the spectrum—later, it would also support the transmission of broadband data over wireless networks. In short, TDMA was the key to a finite room. CDMA was the key to an almost unlimited room.
