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NWAPRS serves: Alberta, British Columbia,
Northwest Territories, |
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The WIDEn-N paradigm settings are an attempt to optimize the APRS network using the currently available hardware. There are certainly better ways to build an APRS network, but until we can get the hardware needed to do the job in place, the NWAPRS group is suggesting that these settings be used. A suggested standard path for a mobile APRS station is: WIDE1-1,WIDE2-1 This will provide you with two hops via the RF network. WIDE1-1 will activate the fill-in digipeaters, which will boost you to the main digipeaters. This path asks the fill-in digipeaters for help of the first hop, as well as the main digipeaters, but only the main digipeaters will respond to the second hop. When within range of the main digipeaters, they will respond to the WIDE1-1 alias, adding the packet to the anti-duping list. The second alias again is acted upon by the same routine, so the digipeater knows whether it has digipeated the packet via the first alias already. This is where the real "magic" of the WIDEn-N paradigm happens. One thing to watch out for is to make sure WIDE1-1 is only ever used in the first hop position. If you used a (BAD) path such as: WIDE2-2,WIDE1-1 (VERY BAD PATH) You would get two hops via the main digipeaters, and one more hop via the main digipeaters, as well as every fill-in digipeater that is within range of those second hop digipeaters. This not a good thing, as the fill-in digipeaters are only supposed to help fill-in holes in receive coverage. Mobile stations should transmit a position report depending on the configuration of equipment they are using, to WIDE1-1,WIDE2-1. Typically a shorter path of WIDE1-1 with a periodicity of once every two minutes is acceptable. Perhaps 3-5 minutes periodicity should be considered for the full path. Again, this depends on individual needs. If it flies: no path, or WIDE2-1, once every minute or two minutes. Kantronics KPC-3 and KPC-3 Plus (For KPC-3, connect GPS data
to Pin 2, GPS Ground to Pin 7 of TNC DB-25 terminal
connector)
If you have a KPC-3 Plus with 8.3 or 9.0 firmware, input the GPS data to the KPC-3 Plus DE-9 pins 2 and 6 (data and ground, respectively). This frees up the DB-25 port, so if you want to run it as a tracker, you can, and if you want to run APRS mobile with a laptop, just plug in the computer cable and go. No other changes are necessary. Additionally, make these settings in the KPC-3 Plus (8.3 or 9.0 only):
*Check the SYMBOLS.TXT file for recommended settings for special event trackers. You can use tactical callsigns such as SAR01, Bike1, EOC1, etc, and then place the station callsign in the BTEXT with a 10 minute beacon. To get the desired symbol, place it in the TO CALL of the UNPROTO line, e.g. U GPSxyz via WIDE1-1,WIDE2-1 where "xyz" is derived from SYMBOLS.TXT. Most common symbols: GPSMV = Car If you operate either the Kenwood TH-D74A or TM-D710GA APRS-capable radios, you know how easy it is to reach over and change the periodicity of your transmissions, and the outgoing path. As a default resource, your settings should be WIDE1-1,WIDE2-1 at once every two minutes or so. However, if you want to transmit every minute, that's OK, just adjust the path down to WIDE1-1. These are very versatile radios, and easy to program "on the fly". You can abbreviate the path settings in the radios: W1,W2 will be transmitted at WIDE1-1,WIDE2-2. Sorry, there is no short path for WIDE2-1, but you can enter W1,WIDE2-1 and that will work just fine. The latest generation Kenwood APRS radios have simplified the process even more. There are several other options, all aimed at size-reduction, for making a tracker. These items inlcude the TinyTrack family and others. The smallest of these is about the size of a 9-volt battery, while the largest is still smaller than a pack of Lucky Strikes (non-filtered, of course). All these devices are designed to either fit inside another key component, like a GPS or radio case, and work towards making a smaller, lighter, tracker. These work great for backpack, balloon, vehicle, or rocket trackers, and several of them work off of 5-12 volts. In any case, you typically program these devices externally with a PC, then set them on their way. With exception of a few, once programmed, they cannot be changed enroute. Your default settings are determined by the type of operation you are using them in, and will vary accordingly. Typically, it won't be necessary to set any of these trackers above WIDE1-1,WIDE2-1, so you can follow the rules for timing (no relay or WIDE1-1 = 1min, WIDE1-1,WIDE2-1 = 2 mins, WIDE1-1,WIDE2-2 = 3-5 mins). Use your best judgment when setting the timing options for these kinds of trackers. Here's some more info on Smart Beaconing.
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