Kenwood TM-D710GE - Manual (Page 48)

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06 APRS Networks
UIDIGI
With UIDIGI activated (On), when a digipeater receives a UI frame with a character string for alias (such as RELAY,
WIDE1‑1, etc.) that matches the alias character string in the digipeater, the digipeater repeats the packet substituting the
callsign from the digipeater’s MY CALLSIGN configuration and adding a completed flag (*).
UIDIGI should normally be off in a mobile. It is not good for mobiles to be digipeating all packets on the channel
because it causes much interference. But sometimes, in special cases, when a mobile is being used on top of a hill or a
special weak area to provide temporary emergency digipeating, then UIDIGI can be enabled with the WIDE1‑1 alias so
that this mobile can serve as the first hop out of an area. WIDE1-1 digipeating only operates on the first hop, so there is
not much damage to the network or to other traffic
MYCALL: W6DJY-1
UIDIGI: ON
ALIASES: WIDE1-1
WB4APR-9 > APK102,
WIDE1-1, WIDE2-1: Test
WB4APR-9 > APK102,
W6DJY-1*, WIDE2-1, Test
Fig. 6-5 Using UIDIGI
UIFLOOD
With UIFLOOD activated (On), when a digipeater receives a UI frame with a character string for alias in the form
XXXXn‑N where XXXX matches the alias character string in the digipeater, the digipeater subtracts 1 from N and
processes the packet reporting only the revised character string so as not to make the frame length too long. The
UIFLOOD technique does not provide traceable paths, so its use is not recommended except for supporting the SSn‑N
or SSSn‑N state or regional paths. Also the example should change to start with SS3‑3 instead of WIDE3‑3. UIFLOOD
should very rarely be used by mobiles.
MYCALL: W4DJY-1
UIFLOOD: ON
ALIAS: MD
SUBSTUTUTION: ID
WB4APR-9 > APK102,
MD3-3: Test
WB4APR-9 > APK102,
W4DJY-1*, MD3-2: Test
MYCALL: W5DJY-2
UIFLOOD: ON
ALIAS: MD
SUBSTUTUTION: ID
WB4APR-9 > APK102,
W5DJY-1*, MD3-1: Test
“MD” stands for
Maryland.
Fig. 6-6 Using UIFLOOD
The UIFLOOD method of digipeating is only a function of a full sized properly configured permanent digipeater. If
a mobile is activated with UIFLOOD, it can cause much unnecessary interference to the network. The only time to
ever activate a mobile with UIFLOOD is in very special cases, when a mobile is being used on top of a hill to provide
temporary emergency digipeating to replace a broken or missing wide area digipeater.
UITRACE
UITRACE functions similar to UIFLOOD with the difference that UITRACE reports the full relay path of digipeaters that
were used to relay the message. UITRACE is the most powerful and traceable digipeating function in APRS. It is the
basis of the New‑N paradigm discussed in 7.4 Digipeaters. Therefore, with UITRACE activated (On), when a digipeater
receives a UI frame with a character string for alias in the form XXXXn‑N where XXXX matches the alias character string
in the digipeater, the digipeater subtracts 1 from N and processes the packet reporting each of the previous digipeaters
as well as itself resulting in a frame length that becomes longer as the message is relayed. Using UITRACE allows you
to confirm the exact routing of any message.