An interactive HF computer link

Since the beginning of this century ionospheric propagation (HF) has been an important medium of radio communications. It has supported commercial telegraphy, telex traffic and military communications. Although it is a communication channel with high data corruption, the low cost of an HF system compared to the satellite for a small to medium number of users, the lower vulnerability in military applications, and the facility to follow the state of the art more frequently due to lower sophistication than the satellite schemes, make it an interesting alternative for communication. However, little consideration has been shown in the use of this medium for computer communications. The need for communications of this type is becoming clear. The authors discuss the utilisation of an HF link as a medium supporting a remote interactive terminal-computer communication.<>