Kenwood TM-D710GE - Manual (Page 47)

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APRS Networks 06
The message can be entered using the Tuning Control on the panel or the numeric keypad on the microphone. When
the message is completely entered, it will be transmitted in an APRS message. Email is transmitted via the IGate and
the APRS server is connected to the Internet.
Internet
APRS Server
TM-D710
APRS software
Email software
From IGate to Server
Server to Internet
Digipeater
Digipeater
Email transmission
Email has been received!
Fig. 6-4 Transmission Flow for Email
Note:
◆ You cannot send email from a personal computer to a mobile station.
Digipeaters (Digital Repeaters)
The greatest feature of APRS is the network that is spreading around the world. The heart of the network is made up of
many digital repeaters commonly referred to as digipeaters. Of course, digipeaters are well‑known among those who
have used packet radio for years. Digipeaters receive data over‑the‑air via radio signal and repeat or relay it onward.
For a voice repeater, two different frequencies are used simultaneously to accomplish this repeater function. However, a
digipeater first receives and stores data, and then transmits when the channel clears.
In the earlier times of packet radio and digipeaters, it was required to specify the callsign of each digipeater station. But
it was difficult to know which digipeater station to use. If moving in a vehicle, you had to constantly consider changing
digipeaters. Now, APRS uses a common generic callsign for all digipeaters referred to as WIDEn‑N, where N is the
number of hops desired through the network (typically 2). The WIDE terminology lets you know the digipeater is in a
good location for repeating signals. A mobile station anywhere only has to specify WIDE1‑1 without needing to know a
specific callsign of a digipeater in order to digipeat their beacon transmission.
APRS evolved over many years beginning in 1992, and there were many inefficient older network concepts that were
still being used in some areas. You still may see references to these obsolete techniques (RELAY, WIDE, TRACE, and
TRACEn-N). By 2004, it was decided it was time to abandon those many older inefficient paths and concentrate on only
the fully traceable WIDEn‑N algorithm. This universal upgrade of the APRS network to just the one simple and traceable
WIDEn‑N concept was called the New‑N Paradigm. Since its adoption, most areas have seen many improvements in
local area APRS reliability. In most areas of the country, the number of hops should be no more than WIDE2‑2 because
additional hops just add too much network load and too much interference from stations far away.
The following sections explain configuration of the TM-D710 for use with digipeaters.