Bob Bruninga, WB4APR

The latest concept has returned to the name of AVRS and can be found at: http://www.ew.usna.edu/~bruninga/avrs.html"

NEW: Look at this new proposed IRLP 5 Digit Numbering Plan.

This AVRS page is attempting to define how we can use the Human/Data Interface of the Kenwood D7 HT and D700 Mobile APRS rigs (Tiny-Web-Pages) to facilitate establishing end-to-end voice links and to push IRLP/ILink data to the front panel of the APRS radio. This concept was initially called AVRS for Automatic Voice Relay System and presented at the year 2000 DCC. (Click here to review paper). But now with the rapid growth or IRLP/ILink and others, the concept has the potential to evolve into a fantastic fully integrated AVRS system. Current growth rates of over 50 nodes per month will exceed 999 by Feb 2003 (See PLOT!). Or if you are new to IRLP, go see the Active-Node-List.

Use of the "AVRS" term for this evolving concept will help differentiate between what "is" and where we are "going"... AVRS is only a human interface overlay to IRLP or I-Link systems and does not obsolete existing users or control systems. See current details.

For additional closeups of the front panel showing the types of data that can be displayed on these "tiny-web-pages" go to my TINY-WEB-PAGE satellite tracking page that shows how they are used to dessiminate satellite tracking info LIVE to mobile users. Now imagine that these lists can also contain IRLP/ILink data, and the built-in end-to-end APRS data exchange can be used to automatically establish end-to-end voice links.

DEMONSTRATION: So you can experiment with how this will look on everyon's D700, download this Active Node File and dump it through a TNC in converse mode over the air to your Kenwood D700! Then you can see exactly how this is going to look on your radio front panel!

The only hardware needed to add this tremendous capability to any IRLP/ILink system is to add a TNC and some software to the PC and turn on CTCSS whenever the node is transmitting voice. This allows the same IRLP/ILink transmitter to also service its users with data between voice use. Thus, the mobile end user only needs one radio for both the voice and the data updates.

Note: We do need to assign 8-character geographic node names to all nodes to make this data fit the existing callsign fields in all APRS data applications. So I went ahead and edited up a list. (Download here) Also, for more details, see the new DRAFT AVRS PAPER HERE

Besides the signalling defined in the paper above, here are some other concepts that can be applied now in your area:

  • AVRS end users can exchange APRS messages prior to, during or after a QSO.
  • STATION list can show up to 40 users on line in the normal format.
  • STATION list can show current ACTIVE NODE STATUS web page for most recently used nodes
  • STATION LIST can also include bearing and range to each IRLP node. (see FORMAT)
  • APRS messages can help establish the IRLP/ILink between any 2 users worldwide
  • APRS Messages can Query worldwide for Station X's currently nearest node (see FORMAT)
  • Single press PM button can configure D700 totally for AVRS/IRLP operations
  • Front panel command can eventually set-up AVRS link directly from station list

    This javAPRS page below displays the current APRS-OVERLAY file of IRLP nodes provided by James Ewen. Ignore the red lines, they connect repeaters with identical frequencies(LABELS) and are an artifact of APRS vehicle tracking trying to "track moving objects"... But no reason why (with a little software) they couldnt show LIVE which repeaters are linked...

    javAPRS Commands (Case Insensitive)
    U or D
    zooms up/down (you may also use PGup/dn)
    L, S, or M
    List stations, Show Status or Messages to Java console
    CTRL or ALT-click
    Centers or Zooms map on clicked location
    Arrow keys
    scrolls map

    Click for World Map

    Click here to download IRLP.POS

    Here are some initial ideas that can be implemented by APRS users to begin recognizing AVRS nodes and concepts. These can be implemented now on APRS independent of progress on the AVRS side...

  • All IRLP/I-LINK users should put "AVRS" in their MESSAGE GROUPS
  • All IGates or AVRS gates should put "AVRS" in their pass-to-rf-always list
  • The APRS Icon for AVRS nodes is "/L"
  • The APRS TOCALL for any special AVRS software is "APVxxx" for "Voice"
  • AVRS mobiles use "IRLPnnn" or "ILnnn" in their status to show their current node.
  • The above IRLP/ILink data base will be added to all APRSdata servers for Queries
  • The term "AVRS" will distinguish this generic concept from specific IRLP/ILink implementations


    Simply put your IRLP node as an object into one of the LText buffers of your local APRS digipeater and set its LTPath to direct and set its rate to 10 minutes. Bingo, every mobile in the area will see it on the front panel of his radio! Here are the formats of the TNC commands for use at the DIGI site:

  • LTP 2 APRS
  • BLT 2 E 00:10:00

    In the above the LAT/LONG must be the exact number of digits, but you can replace the hundredths of minutes with TWO spaces which will give a position ambiguity of one mile if you want to protect the exact location of the repeater. The CCCCCC is the callsign of the repeater, #nnn is the IRLP node number, and then the frequency and tone of the repeater


    The minimum data necessary for the AVRS concept makes it possible to send both voice and DATA on the same channel so that all of AVRS can be done entirely on BAND A of the Kenwood D7 and D700 leaving the other band free for all other mobile ham radio applications. Also, with a combined voice/data channel/ single channel radios can be used by other experimenters to build compatible systems. Here is how to set up your Kenwood:

  • Kenwood radio sets Band A to the IRLP VOICE channel. He configures his interntal TNC to BAND-A and sets CTCSS decode ON. THis way, Band A can serve as BOTH an IRLP data exchange channel with the radio front panel and also as the VOICE channel! The speaker is muted for all data, and only opens when the IRLP node sends CTCSS and voice.

  • The user can now fully use BAND-B for any other purpose and Band A handles both IRLP/ILink voice operations and APRS data exchange with the node..

  • At the IRLP node site, the TNC listening and sending acts like an "IGATE" in all other respects. Thus the APRS user is injected into the world wide system for tracking and messaging just as if he was on 144.39. He is tracked on all web pages and he can send/receive APRS messages worldwide.

  • The above user, however, cannot see other local APRS activity. Thus the IGate must be smart enough to listen for other "local" activiy on the APRS internet system and forward that back out on the common IRLP channel. This is actually GOOD news in the sense, that the "smarts" in this IRLP_IGate code can "filter" as the locals decide so that they only have to watch what they want to watch...

    WOW. We can really do some neat things here!

    Remember, we are not trying to re-invent APRS, and we are not trying to muckup existing IRLP oeprating procedures. We are simply exploring ways to overlay ideas to allow a marriage of mobile data exchange capabilities built into the Kenwoods, HAMHUDS. MIM's (and anything else someone wants to cobble up) to facilite long distance voice/data communications between end users via the internet...

    de WB4APR@amsat.org, Bob

    You are visitor: since 4 Dec 2001. .

    The Naval Academy is a registered user of APRS and WinAPRS. The purpose of this web page is to show several applications currently in use at this site and should not be considered as an advertisement or an endorsement of any commercial product.