Stations can tap into this stream directly, and a number of databases connected to the APRS-IS allow Web-based access to the data as well as more advanced data-mining capabilities. The "smart" TNCs are capable of determining what has already happened with the packet and can prevent redundant packet repeating within the network. Reporting stations use a method of routing called a "path" to broadcast the information through a network. In a typical packet network, a station would use a path of known stations such as "via n8xxx,n8ary. In APRS, generic call signs are assigned to repeater stations to allow a more automatic operation.
It has grown to encompass just about every aspect of Amateur Radio. TXT by Bob Bruninga APRS is a real-time tactical digital communicatons protocol for exchanging information between a large number of stations covering a large local area. As a multi-user data network, it is quite different from conventional packet radio. APRS is different from regular packet in four ways. First by the integration of maps and other data displays to organize and display data, second, by using a one-to-many protocol to update everyone in real time, third, by using generic digipeating so that prior knowledge of the network is not required, AND FORTH, since , a worldwide transparent internet backbone, linking everyone worldwide. APRS turns packet radio into a real-time tactical communications and display system for emergencies and public service applications and global communications. Normal packet radio has only shown usefulness in passing bulk message traffic Email from point to point.
Description , and Basic code , and mm-data. The Automatic Packet Reporting System was designed to support rapid, reliable exchange of information for local, tactical real-time information, events or nets. The concept, which dates back to the mid 's, is that all relevant information is transmitted immediately to everyone in the net and every station captures that information for consistent and standard display to all participants. Information was refreshed redundantly but at a decaying rate so that old information was updated less frequently than new info.
Packet radio has rarely been used effectively in real-time events, where information has a very short life time. To solve this problem, APRS avoids the complexity and limitations of trying to maintain a connected network. It uses Ul frames to permit any number of stations to participate and exchange data, just like voice users would on a single voice net. Stations that have information to contribute simply transmit it, and all stations monitor and collect all data on frequency.