[aprssig] APRS "text messaging" over long distances

[Steve Dimse]

On Oct 8, 2005, at 8:30 PM, Curt Mills wrote:

>
>
>> Does every iGate put my message out or are the iGates smart enough  
>> to know
>> where we're located and only put out a message if it heard the  
>> recipient?
>>
>
> They keep track of what stations they've heard on local RF over the
> last hour.  If a message comes along on the internet for one of
> these, they gate it to RF.  Same for ack's.

Just to be clear, what is "local RF" is not just heard directly.  
Generally it is defined as two hops, some IGates have the number of  
hops hard-coded, some allow the operator to specify the number.

Steve K4HG