A major concern for distance learning is the connectivity and transmission speed between the teaching site and the students.
Some distance learning technologies use analog transmissions and some use digital.
The trend is to move toward primarily digital systems. The transmission capacity of a cable or a technology is referred to as the bandwidth. The greater the bandwidth, the greater the amount of digital information that can be transmitted per second. There are several options available now or in the near future that will help to expand the bandwidth and increase the speed of information transfer. These options include ISDN lines, T1 lines, ADSL modems, cable modems, and satellite delivery.