Kenwood TH-D72A/E - Manual (Page 68)

7 APRS NETWORKS
60 CONTENTS TH-D72A/E
Example 2:
This is a general recommendation for permanent digipeaters installed at a high location.
• Digipeat
Digipeat(MyCall): On
• UIdigipeat
UIdigi: On
Aliases: SAR
(other local paths can be defined here)
Note: SAR stands for “Search and Rescue”.
• UIflood
UIflood: On
Alias: SS or SSS
Substitution: ID
• UItrace
UItrace: On
Alias: WIDE
New-N Paradigm
In 2004, the recommendations for APRS path configuration were drastically simplified. And this was
called the New-N Paradigm. This plan eliminated all use of the simple paths of RELAY, WIDE and
TRACE. We recommend you to avoid any references to these paths and ignore them. Instead, the
New-N Paradigm introduced three major routing paths, WIDEn-N, SSn-N and TEMPn-N. There n-N
is set to the number of hops (usually 2-2 or less).
WIDEn-N National Standard:
The WIDEn-N path was designated the National Standard so that it would work everywhere and
should be used for routine operations. Limiting the hops to 2 hops or less assures that the packets
cover the local area and region (and will get to an IGate somewhere). And at the same time the
packets do not go any farther or add unwanted interference in other areas. This drastically improved
the efficiency and reliability of the APRS national network. The only disadvantage of the WIDEn-N
standard was that digipeaters could only be built with specialized modern APRS TNC hardware and
could not take advantage of thousands of old TNC for small local networks. To solve this problem,
the WIDE1-1 “first-hop” concept was developed.
WIDE1-1 Fill-in Digipeaters:
Old TNC hardware of WIDE1-1 fill-in digipeaters only allowed a single digipeater ALIAS. In the early
days of APRS we used the generic alias of “RELAY” so that any TNC or home station could be used
as a local digipeater. But this produced too many dupes and was abandoned in 2004. In its place,
we substituted the path of “WIDE1-1”. The beauty of this ALIAS Is that it can act both as a simple
generic ALIAS but at the same time, be recognized by all of the modern WIDEn-N digipeaters as
well. These modern TNCs with the WIDEn-N mechanism all avoid making any duplicates. This
allows local areas to put up small area, local coverage WIDE1-1 digipeaters using any old TNC as a
first hop for mobiles driving nearby. The mobile can hit these fill-in digis in weak signal areas but at
7.4.5 Proper Configuration (written by Bob Bruninga, WB4APR)