Ericsson, the Swedish telecommunications giant has announced that they will soon be offering 64 kbps data links over the GSM-based digital cellular telephone network. On the landline side, the data is probably sent down conventional ISDN data connections. Based on Ericsson's advertising, we can presume that in the near future, you will be able to buy a digital still picture camera with builtin high speed GSM digital cellular technology - instantly transfer pictures to a recipient. Imagine the possibilities of this technology for public safety, traffic control, or journalism. Using a PC on each end of the link also opens up possibilities in digital voice communications.
Hams are incredibly far behind in the experimentation and deployment of digital voice technology.
At least three kinds of digital technology are being deployed in cellular telephony systems. These technologies are being deployed because digital technology enables anywhere from roughly a 2 to 10 times capacity improvement in frequency usage. That means serving 10 times more users in the same space as an existing analog system. The FCC is pushing all radio services to develop more frequency efficient technologies. Hams are likely going to have to do the same.