APRX

aprx pada awalnya merupakan aplikasi APRS iGate received only, saat ini sudah di kembangkan untuk mampu melakukan digipeating, dan Tx-iGate. aprx dapat di operasikan di sistem minimal UNIX-like, atau yang mendukung library POSIX libc dasar.

Saat ini juga tersedia beberapa paket binary untuk lingkungan Fedora dan Debian. Platform lain juga dapat digunakan karena aprx dapat dengan mudah di compile. aprx sudah di test di compile di sistem keluarga BSD.

Aplikasi ini dapat di install di sistem UNIX-like, beberapa file konfigurasinya perlu di atur. Jika ini dilakukan maka aprx dapat:

• Menangani banyak modem radio yang tersambung padanya.
• Optional: me-relay paket APRS dari penerima radio ke jaringan APRS-IS (http://www.aprs-is.net).
• Optional: digipeat paket AX.25 dengan dan tanpa aturan APRS NEWn-N
• Optional: relay paket APRS dari network APRS-IS ke kanal radio (Tx-iGate)

Aplikasi ini dapat digunakan di lingkungan dengan sumber daya yang terbatas, seperti mesin embeded yang kecil seperti router yang mampu melakukan jaringan TCP/IP.

A receive-only Rx-iGate does not need any sort of licenses in most parts of the world where radio amateur hobby is permitted to begin with.

On version 2, the Aprx has gotten ability to do APRS Digipeater function, Aprx Tx-iGate, as well as a variation of that called Viscous APRS Digipeater, which is excellent choice for a Fill-In digipeater like on a mobile station. Viscousness means that it will listen for other copies of same packet for a small configurable number of seconds, and if it hears same packet only once, it will do normal digipeating for it.

== Distribution ==The software is downloadable at:

http://ham.zmailer.org/oh2mqk/aprx/

Manual is downloadable at:

http://ham.zmailer.org/oh2mqk/aprx/aprx-manual.pdf

Features

Originally this software was written for the need of densifying receiver network feeding things to APRS-IS network, and the software did only things necessary for a receive-only APRS iGate. New version can also do stand-alone Digipeat of APRS packets as well as digipeat and Rx-/Tx-iGate.

The basic design criteria have also included something called minimum technology, whereby the software does not need any external software or libraries in order to function. However when additional technology is available, some are being used (like Linux kernel AX.25 network, POSIX Threads, etc.) This also minimized system resource requirements, which in case of APRS iGates do include networking, but can be done with very small machines, like Linux with 8 MB RAM. Also the software should be able to function on any minimally compliant POSIX system.

Important goal has been to keep R/W memory footprint as small as possible, and on general purpose i386 Linux a single radio port iGate+digipeater is now around 250 kB of R/W memory allocations. Of those around 100 kB are directly for the Aprx's own usage. Rest is probably glibc's use.

For Rx-iGate use the minimum configuration with tunable parts highlighted:

 mycall  OH2XYZ
 <aprsis>
    server   rotate.aprs.net  14580
 <aprsis>
 <interface>
    serial-device /dev/ttyS0  19200  8n1    KISS
 </interface>

For a stand-alone APRS Digipeater the configuration would be:

 mycall  OH2XYZ
 <interface>
    serial-device /dev/ttyS0  19200  8n1    KISS
 </interface>
 <digipeater>
    transmitter  $mycall
    <source>
       source     $mycall
    </source>
 </digipeater>

A stand-alone Digipeater can be made into Digi + Rx-iGate by adding the <aprsis> block on its configuration.

As this software must operate in extremely memory limited systems, its writers have seen no need to make any memory hungry configuration tools, and instead the installer must be able to edit the text format configuration file by means of some simple editor (like nano) existing in the system, or perhaps downloading the file from external editor.

Operating systems

Observed to work:

• Linuxes (Fedora, RedHat, SuSE, Debian) (--with-pthreads)