Amateurs have been using packet radio on the HF bands for as long as packet radio has existed. And we have been less than happy with the results for about the same length of time.

The problem is centered on the way packet radio operates. Data is packaged into individual frame, which are then sent by the transceiver using two-tone audio frequency shift keying. If even one bit is corrupted within a packet radio frame at the receiving end. the entire frame must be re-transmitted. If the signal path is marginal, several retransmissions may be required to get the information through.

At VHF and above, packet is typically sent using FM transceivers and line-of-sight links, so corruption is kept to a minimum and the data flows reasonably well. At HF, it is a whole different ballgame. Now the packet signal must compete with noise, interference, and fading. Unless the signal path between two stations is particularly stable, corrupted data can become an enormous problem. The result can be a seemingly endless round of re-transmissions, or a complete communication breakdown.