[aprssig] New n-N Paradigm getting better!
Robert Bruninga
bruninga at usna.edu
Sun Jan 9 14:22:48 EST 2005
This is a new draft of the overall USA National Plan for all APRS
digipeaters under the New n-N paradigm as it has evolved
over the last month of discussion. Notice that WIDE2-2,
SS2-2, RELAY and WIDE are supported at least one hop EVERYWHERE.
This table is followed by a second table to show the proper
settings for the TNCs. And a 3rd table to tell new users what
to use.
The New n-N Paradigm is based on one primary objectives, that is
to greatly reduce QRM from distant packets with the goal to
vastly improve local reliablity of APRS everywhere. It does
this through these significant features:
1) Recognizing the ALOHA limit as a universal measure of 100%
channel capacity that gives good results in all topologies.
1) Support of universal paths RELAY & WIDE & WIDE2-2 everywhere.
2) Traceability to the first digi in all cases (except LNKn-N)
3) Encourage a single digi entry in a path to eliminate the
extra dupes caused by multiple generic entries like
RELAY,WIDE, and WIDE,WIDE, etc.
4) Eliminate WIDEn-N for N greater than 2 in those areas where
it cannot be supported due to high user density and overload
View this table in FIXED FONT only. This table suggests to APRS
planners what kind of digi system to install at a given location
based on the number of surrounding users and the number of
surrounding digipeaters within the ALOHA limit. In the first
column, an example is also provided... This table may be hard to
read in Email due to fonts and line-wrap. So I will post it to
a fixed-font WEB page on Monday.
ALOHA USER DIGI TNC* DOES UI- UI- ENFORCEMENT
USERS DENSITY DESIGN TYPE PATHS FLOOD TRACE METHOD
----- --------- ------- ---- ------ ------ ----- -----------
1200 in range 9600bd 8 of RELAY none none 1 hop only
of this UHF X- any WIDE No n-N
LA in high digi band w/ kind W2-2 2-2 = once
10 yr router SS2-2
----------------------------------------------------------------
360 in range 1200bd APRS RELAY none none 1 hop only
of this UHF X- WIDE No n-N
LA high digi band W2-2 2-2 = once
soon SS2-2
----------------------------------------------------------------
180 in range 1200bd APRS RELAY none none 1 hop only
of this simplex WIDE No n-N
Big high digi W2-2 2-2 = once
Metro SS2-2 VIGILANCE
----------------------------------------------------------------
90 in range 1200bd APRS RELAY LNKn-N SSn-N 2 hop only
of this & simplex n-N WIDE small No WIDEn-N
typcal nearby 3 W2-2 state W2-2 = once
city digis SS2-2 only VIGILANCE
LKn-N
----------------------------------------------------------------
60 in range 1200bd APRS RELAY LNKn-N SSn-N 2 hop only
Avrge of this & simplex n-N WIDE No WIDEn-N
East nearby 4 W2-2 W2-2 = once
Coast digis SSn-N VIGILANCE
LKn-N
----------------------------------------------------------------
40 in range 1200bd APRS RELAY LNKn-N SSn-N 3 hop only
of this & simplex n-N WIDE Wn-N No n-N
Kansas 8 other Wn-N *
digis SSn-N* VIGILANCE
LKn-N*
NOTES:
* An "APRS" digi is any digi that supports up to 4 callsign-
substituting aliases. This includes the PacComm TRACE-ONLY digis.
An "n-N" digi is any "APRS" digi that also supports UIFLOOD/UITRACE.
*** In the low-density areas where WIDEn-N, SSn-N and LNKn-N
are supported, any one digi can only suppport 2 of the 3.
Usually this will be Wn-N and LNKn-N since SSn-N is not needed
and since SS2-2 is at least supported one hop everywhere.
"SSn-N in small states" means most of the state or ARRL section
can be hit with 2 hops outward from the center. Thus a SS7-7
path really only goes 2 hops on average to the edges of this
state's or section's digis, though some outlying areas may
actually use, 3, 4 or 5 to get there
"in range of N other digis" means of the same or more open digi
types. If there is a big city digi of the *enforced 1-hop* type
that is 2 hops away, then it and all its usrs are not involved
in this count, because it's surrounding ring of *enforced 2-hop*
digis will not inject QRM into yours nor can yours inject QRM
into it.
VIGILANCE means that the digi is vulnerable to users of multiple
strings of aliases such as RELAY,WIDE,WIDE,a nd WIDE,WIDE,WIDE
which cause exponential dupes and damage to the network. We must
erradicate these paths by user vigilance and education. Only
UIDIGI-ROMS and DIGI_NED digipeaters can actually enforce this
rule. Thus all other areas have to watch what people are using
and educate them.
TNC SETTINGS TABLE FOR THE KPC-3+ TNC:
This next table suggests the settings for the KPC-3+ digi for
each of these ALOHA and DIGI design types. We will fill in the
equivalent settings for UIDIGI-ROMS and DIGI_NED TNC's later
ALOHA MYALIAS UIDIGI UIFLOOD UITRACE
USERS ALIASES
----- ------- ------- ------------- -------------
1200 GEONAME RELAY none none
360 WIDE
180 WIDE2-2
SS2-2
90 GEONAME RELAY ##LNK,30,NOID SS,30
60 WIDE
WIDE2-2
WIDE3-3
40 GEONAME RELAY ##LNK,30,NOID WIDE,30
WIDE
WIDE2-2
SS2-2
NOTES:
1) GEONAME is a geographical descriptor of the coverage of this
digi. Please use well-known labels that everyone can figure out
This has to fit in a 6 character FCC callsign type field, so I
suggest you could use SSID's of -1, -2, -3, -4 for North, South,
East and West of a well known city or area.
2) Notice that all of the UIDIGI aliases that have a hop count
are actually enforced single-hop results in that digi.
3) If there is no 300+ mile interstate passing anywhere near this
digi, then leave UIFLOOD blank. Making an interstate ##LNKn-N
for an interstate that can be covered end to end with 4 hops or
less is a useless waste of time.
USER GUIDANCE:
The whole purpose of this New n-N Paradigm is to bring APRS back
to the KISS principle where the rules for the user are simple.
The following table will try to help those users.
USER DESCRIPTION PATH DISCUSSION
------------------------------------- ------- ----------------
FIXED New User, No Clue: WIDE2-2 works everywhere
FIXED ROUTINE where SSn-N is used: SS2-2 minimum QRM
FIXED SPECIAL needing STATE coverage: SSn-N Use with vigilance
FIXED in Wilderness WIDEn-N area: WIDEn-N With N < than ALOHA
MOBILE USER, No Clue: WIDE2-2 works everywhere
MOBILE NATIONAL TRAVELER: WIDE2-2 works everywhere
MOBILE INTERSTATE D7/D700/etc RELAY,##LNKn-N for long haul
MOBILE WITHIN STATE which has SSn-N SS2-2 or SSn-N for special
MOBILE PREDOMINANTLY in WIDEn-N areas WIDE3-3 May still get one
Notes:
SSn-N means a two digit State Abbreviation in small and medium
states where it typically takes only 2 hops radially outward
from the center to hit most of the state. (4 hops across). In
larger states, the state is typically broken down into 2 or more
more manageable ARRL sections, such as EPA and WPA for East and
West Pennsylvania for example.
I think we are getting close to the final answer.
Good luck.
de Wb4APR, Bob
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