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File List | 1993-05-25 | 3.2 KB | 51 lines |
- INCLUDING APRS PROTOCOLS IN BBS and NODE SOFTWARE
-
- This information is intended for BBS SYSOPS and the writers of BBS and NODE
- software. Please consider the following advantages to including APRS protocols
- in your station operation.
-
- Since APRS allows stations to see the network topology in real-time, it is
- ideal for determining the locations of all neighboring BBS's and NODES. If
- BBS's and NODES simply included the 19 characters of LAT/LONG in a periodic UI
- frame, all users could see geographically where the system is located. For
- permanent fixed sites such as BBS's and NODES, this beacon could probably be
- transmitted once every hour or so. The exact format of the UI frame should be
- as follows:
-
- BBSXX>APRS:!DDMM.xxN/DDDMM.xxW/comments as desired to end of line
-
- For BBS code writers, this process can be enhanced by making the BBS
- respond to APRS Query packets. One of these packets is transmitted whenever an
- APRS station initializes his program. On receipt of an APRS Query packet, all
- stations on frequency set a one minute random number timer and respond sometime
- in that minute with their location. This way, any APRS station can obtain the
- location of all stations on the frequency within one minute of comming on
- frequency. The format of the APRS Query packet is W4XYZ>APRS:?APRS?. By
- including the code in NODE and BBS software to respond to APRS Querys, the
- periodicity of the APRS position beacon can easily be set quite infrequently
- since stations can request the BBS position at any time.
-
- I have one other request to BBS SYSOPS. Since APRS contains a packet
- BEACON parser to display to users all BEACONS heard on frequency, this is an
- excellent way for stations to capture MAIL-FOR beacons. In this way, APRS
- stations simply call up their LATEST BEACONS display and see if there are any
- BBS's reporting mail for them. Unfortunately, the parsing algorithm in APRS
- only recognizes BText which occurs on the same line as the packet header.
- MAIL-FOR which is listed on a new-line after an ID Beacon do not show up in the
- APRS system. Only the ID portion of the packet is retained. For this reason I
- would like to request BBS SYSOPS to modify their MAIL-FOR beacons to keep the
- beginning of the MAIL-FOR list on the same line as the packet header. By
- allowing APRS stations to check for mail without even logging on, you are
- helping reduce congestion on the channel. Presently, most stations do not see
- MAIL-FOR beacons because they scroll off the screen too rapidly. APRS grabs
- all BEACONS heard and retains them.
-
- Please play with the APRS software and load some of the backup and
- demonstration files included. I'm sure you will find APRS to be an exciting
- new capability for packet radio which can make packet radio much more
- responsive in real-time communications.
- Finally, ambitious code writers could add code in their BBS's to capture
- all APRS position reports heard on frequency. These reports could be retained
- in a file and be made available to local users. One of these files, if
- downloaded, can be loaded by APRS users to display the locations of all
- stations ever heard on the frequency!