Packet Radio
What is Packet Radio?
Packet radio is a development of RTTY, invented in the 1970 by workers at the University of Hawaii. Like RTTY, it is an FSK (frequency shift keying) system, but it differs from RTTY in two respects. The speed of data transfer is much faster than traditional RTTY, and the data is sent in blocks, or "packets" rather than in a continuous stream.
Sending the data in packets allows stations to take turns transmitting, and each is able to check received packets for errors and to send the other station an acknowledgment that each packet has been received error free.
Packet also has the advantage that it can store messages to allow retrieval at a later time.
The mode became very popular in the 1980s, and it is still widely used for transmitting messages and maintaining bulletin boards.
A major application today for amateur packet radio is Automatic Position Reporting System (APRS), where stations use a GPS (Global Positioning System) receiver to transmit their precise geographic location.
Packet radio systems originally used a terminal node controller (TNC), which is a small modem that performs the same functions as an RTTY terminal unit, plus various logic functions such as sorting the message data into packets. Nowadays it is increasingly common to replace the separate TNC with PC software emulation that uses the computer sound card.
The WIA Packet Radio Directory
The packet radio directory was last updated in 2017, and it is no longer being maintained. For historical information only, the 2017 listing can still be downloaded by clicking the link below.
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Page Last Updated: Tuesday 20 August 2019 at 12:55 hours
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