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[aprssig] "Emergency!" test convention?

Fritz Anderson fritza at manoverboard.org
Wed Jul 21 16:08:19 UTC 2004


What is your response to the problem that on at least a couple of 
levels, the APRS public will not get the word?

1. Putting a quiet period in the spec doesn't put it into installed 
software. Test messages will be flagged by all the software now in use 
as real. Persons using existing software will post real emergencies 
during the quiet period in ignorance that other stations may feel free 
to ignore them. The majority implementors of Mic-E emergency beacons, 
the Kenwood radios, can't be updated to warn posters or filter tests, 
and even if they could, they have no clocks to trigger the filters and 
warnings.

2. Putting a quiet period into the spec doesn't put it into people's 
heads. Practically nobody will read the spec, but if a quiet-period 
operating standard is to work at all, it would have to be understood by 
practically everybody.

3. Most APRS stations have access to the correct time, but that 
majority is surprisingly small. To be sure, many of the mis-set clocks 
are off by whole hours, and so can correctly recognize the top of the 
hour, but this leaves the computers whose clocks were set by the "it's 
about noon" method, and the very large number of stations -- we come 
back to the Kenwoods -- that have no clocks at all. These stations will 
not reliably filter test messages or handle emergency messages.

My instinct is that your proposal triggers false alarms in almost all 
stations in the short run, and that there's no way in the long run to 
prevent false alarms in a significant minority of stations. Am I 
missing something?

	73 de WT9T
	-- F

On 21 Jul 2004, at 9:07 AM, KC2MMi wrote:

> So may I suggest adding a small point to the APRS spec? From two and 
> half
> minutes before the hour, to two and a half minutes after the hour, 
> every
> hour, that five minute period be set aside for emergency beacon tests. 
> Any
> signal received in that window will be treated as a test to be 
> ignored. Any
> signal continuing after that period, or sent before it, would be 
> treated as
> a real emergency signal of course.





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