WIDE1-1 vs. WIDE2-1

[Davepar]

Finally checking back in. Thanks for all the good info.

I should mention that the guy that showed up on my doorstep was very nice about the whole thing. He said he tried searching for me on the internet. Guess he used "David" instead of "Dave", as I'm the number one result for my name on Google. Even beating out a famous musician.

I haven't tried WIDE2-1 yet, but I expect it will work very well. The mountain-top digipeaters around here seem to pick up lots of the packets anyway. According to my visitor, my packets can be seen all the way down in Portland as it hops the local mountain-top digipeaters. I certainly didn't mean for that to happen.

I'm guessing most of us don't care how often our packets are repeated over RF, as long as they get onto the internet. Is every digipeater internet connected? If not, it would be nice to have something like WIDE2-G that says repeat it until it gets on the net via a gateway.

[Sam Buchanan]

Originally Posted by Davepar

I haven't tried WIDE2-1 yet, but I expect it will work very well. The mountain-top digipeaters around here seem to pick up lots of the packets anyway. According to my visitor, my packets can be seen all the way down in Portland as it hops the local mountain-top digipeaters. I certainly didn't mean for that to happen.

I'm not sure using just WIDE2-1 will make a huge difference in how far the mountain-top digis transmit our packets. Leaving out WIDE1-1 just keeps the low-power fill-in digis (often home stations) from repeating our packets. Once the big repeaters pick up our packet, things are out of our hands. An airborne tracker creates a scenario with its great range that ground-based trackers don't have to deal with.

I'm guessing most of us don't care how often our packets are repeated over RF, as long as they get onto the internet. Is every digipeater internet connected? If not, it would be nice to have something like WIDE2-G that says repeat it until it gets on the net via a gateway.

Every big digi is not an iGate, in fact most aren't since the big remote digis won't have access to a broadband internet connection. Many iGates, such as mine, are not repeaters at all, just receiving stations, often in homes since that is more likely to offer internet access.

I'm not sure there is much we can do beyond using WIDE2-1 to control how far our packets get hopped. WIDE2-1 limits our packet to just one hop by the big repeaters (no hops by the little fill-in guys since they only respond to WIDE1-1), but since the big boys are doing the hopping, your packet might still end up in Portland.

Here is a page that offers some background on APRS paths. It is a little dated but a careful read will provide insight into how this WIDEn-N stuff impacts our trackers and the APRS newwork. Be sure you jump down to the "New Paradigm" section to see how digis are currently handled:

http://wa8lmf.net/DigiPaths/index.htm

I continue to be impressed (and grateful) to the very clever folks who thunk up all this APRS stuff.

[grantcarruthers]

I suppose a real solution would be a system that listens for clear freq and if not available after a programmed period, transmits anyway. Play nice when possible and then assure usefulness to our needs. Maybe to next product out of Byonics could support that?

[tc1234c]

I have been reading the discussions in this thread and learned a lot. At the same time I have been working with my local/area hams to find the best setting for my tracker (micro-trak 300). I used to set my path as WIDE1-1, WIDE2-1 and fast rate at 60 seconds. Although I live in a sparsely served area (southern Ohio), I noticed a lot of conflicting packets (speed >500 km, etc.) and some bad coordinates. At 3,000' my packets are picked up from >100 miles away by several i-gates and digis. My new settings are WIDE2-1, fast rate at 90 seconds, and "only send valid". I did cut out a lot of home digis, but still get my packets in through distance i-gates. On my weekend trip to Indianapolis, I noticed that there were no conflict and bad packets! I am happy that I used minimum resource yet still accomplished my goal. I fully understand that each of us have different missions in mind and that will require different settings. For me, the primary purpose of the tracker is to allow my family and friends know where I am. Longer packet interval is perfectly fine.

(The contents of the following link will change soon after 5/27/2008).
http://aprs.fi/?c=raw&call=KD8IIR

[vlittle]

I've found the same thing. Wide1-1 and higher packet rates just lead to more packet discards. I am keeping Wide1-1, Wide2-1 as a secondary configuration for low altitude operations, and I will continue to experiment with low altitude coverage.

V

[vlittle]

Here's an update on APRS performance.

I replaced my temporary mounting of the MicroTrak 300 with counterpoise, and hard-mounted it to my seat back brace (right behind my right ear). The antenna is bent slightly to clear the canopy, and the whole shebang is well grounded.

Todays performance test was two runs, one at 1500' and the other at 2500' feet.

Both had similar performance, and were much better than my first runs to the same geographic area.

See http://aprs.fi/?call=va7vrl&mt=m&z=11&timerange=3600 (choose May 28 and 6 hours if you need to).

Compared to the May 22 run to the same area (east of my home airport), the performance was much better, with few discarded packets.

I will publish photos of the whole setup soon, so that you can see the install.

Vern

[rpellicciotti]

I have been following APRS for about a year now and I am just about ready to take the plunge. I have read just about everything I can find on the internet about it and I think I understand some of it. I agree with Allen's suggestion. It seems to me that we need to pick a freq for airborne operations and support it with our own i-gate network. I am willing to commit to putting in a i-gate in my area.

[vlittle]

Originally Posted by rpellicciotti

I have been following APRS for about a year now and I am just about ready to take the plunge. I have read just about everything I can find on the internet about it and I think I understand some of it. I agree with Allen's suggestion. It seems to me that we need to pick a freq for airborne operations and support it with our own i-gate network. I am willing to commit to putting in a i-gate in my area.

It would be helpful if you posted your name so that we know who we are dealing with. It sounds like you do not have an amateur radio service license-- that's a good first step.

A discreet frequency would defeat the purpose of APRS-- using the digipeater/igate infrastructure that's in place to track our positions. The solution to having too much traffic on one frequency is to only use as much transmit power as required. For me, 300 mW seems to work fine.

APRS (and for that matter the 2m band) uses frequency modulation. That allows multiple transmitters to talk at the same time (within reason) and for the digipeater's receiver to lock on to the strongest receive signal. Thus, with low power transmitters and a network of digipeaters, we can have a lot of stations in use at once.

[kevinh]

Just another note in favor of just using WIDE2-1.

I recently changed my config (KI6GII-1) to remove the WIDE1-1 at the head of the path and reception still seems very good, without lots of home stations rebroadcasting my packets.

It also seems to have elimininated most of the duplicate 'too many packet updates in <5 secs' problems.

Unless one finds a reason for using WIDE1-1, I'd say we should all be good citizens and use WIDE2-1.

;-)