[aprssig] Re: APRS SSn-N Spec.

Stephen H. Smith wa8lmf2 at aol.com
Thu Nov 29 18:58:49 EST 2007

Scott Miller wrote:
>> In the German APRS-Forum (http://www.amateurfunk.de/aprs/forum/) we 
>> are currently discussing this issue.
>> To achieve a unique structure for SSn-N, we could use the country 
>> codes defined in ISO 3166-1 and the subdivision codes defined in ISO 
>> 3166-2 
>> (http://www.iso.org/iso/country_codes/background_on_iso_3166/iso_3166-2.htm). 
> Considering the size of some countries in Europe, is it even worth 
> using the subdivisions?  San Bernardino County is larger than 
> Switzerland, and it doesn't rate its own SSn-N designator.  California 
> is larger than Germany and has (I think) two designators, mostly due 
> to how long the state is in the N/S direction.

The point of the SSn-N paths is to limit the volume of APRS traffic to a 
level below the Aloha overload threshold for a given network area.  This 
will be (approximately) determined by the absolute population (and 
therefore the number of APRS hams) in a given region. 

Since the population density of Europe is, on average, far higher than 
most of the US, it makes sense to segment Euro SSn-N regions to areas 
smaller than an entire nation, even though many nations are only the 
size of many U.S. states.


Stephen H. Smith    wa8lmf (at) aol.com
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