Kenwood TM-D710GE - Manual (Page 7)

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APRS Operation (Written by Bob Bruninga, WB4APR) 01
Situational Awareness
APRS provides situational awareness to all operators of everything that is going on in his local area, whether it is
weather reporting, traveler info, direction finding, objects pointing to EchoLink and IRLP, or traffic reporting and
emergency response. All of this while providing not only instantaneous operator‑to‑operator keyboard messaging
capability for special events, but also an always‑on Voice Alert backchannel between mobiles in simplex range. There
is even an APRS interface to the Winlink system called APRSLink so that mobiles can send and receive email without
needing a PC. Think of APRS as a signaling channel to reveal all amateur radio resources and live activities that are in
range of the operator at any instant in time.
Participation
Although APRS offers phenomenal capabilities for managing and displaying local information, an overarching design
assumption was that in most applications, APRS would not be used by most operators at an event or by every member
of a club, and very few devices could actually report their own position. The design assumption was that manual entry
and management of large numbers of objects would be a major function of APRS and APRS operators in order to fully
represent the situation. Further, Bulletins and Announcements would keep everyone informed of the same information at
the same time. Operator Messages would communicate important information in the background without encumbering
voice nets.
Ubiquitous Operations
Consistent with providing information on all resources within range, APRS must also work across all boundaries and in
all areas of the continent for all travelers. For this reason, 144.390 MHz is dedicated to APRS throughout North America.
Other continents have similar single frequencies such as 144.800 MHz in Europe and 145.175 MHz in Australia. Also,
after 14 years of evolution, APRS was greatly simplified beginning in the 2004 time frame to eliminate obsolete and
inefficient routing. See the New-N Paradigm.
Now, there is only one recommended PATH everywhere, and it is VIA WIDEn-N for fixed stations where N is usually 2 in
most metropolitan areas and no more than 3 in very remote or isolated areas far from cities. Mobiles can use a path VIA
WIDE1-1,WIDE2-1 in those 2-hop areas to gain help from nearby WIDE1-1 fill-in digipeaters. See the high density areas
in the map below:
Fig. 1-2 APRS User Density