[aprssig] New n-N Paradigm FACTS

[Greg Noneman]

Bob,

I think you may now see why we HAD to go to strictly WIDEn-N in 
Southern California several years ago.  Some of the APRS clients at the 
time had default paths of RELAY, WIDE or RELAY, WIDE, WIDE.  You can 
see how it doesn't take too many of these to completely consume the 
channel.  Going to WIDEn-N had a tremendous impact. Yes, some people 
abuse the path length, but the impact is nothing like that of the 
WIDE,WIDE,WIDE,WIDE,WIDE paths we had back then.  And user education 
has resulted in a majority of the packets now being sent to WIDE2-2.

All this being said, there is still room for improvement.

73,
Greg
WB6ZSU


On Jan 22, 2005, at 1:16 PM, Robert Bruninga wrote:

> This is the real truth about the New n-N Paradigm.
> WITH NUMBERS!
>
> The New n-N Paradigm  is *not* a crusade against WIDEn-N,
> just large values of N.  In fact, half of the crusade is to get
> rid of dupe-generating W,W and W,W,W paths (and R,W
> and R,W,W) and getting those users to switch to WIDE2-2
> (or SS2-2) in busy areas or eastern states..
>
> Here are the numbers based on 1200 packets over 1 hour near
> Baltimore MD representing 110 separate callsigns.  In our area
> only about half the digipeaters support n-N.  So this may not
> be at all representative out west, but it is representative of the
> Eastern Seaboard which we must fix.
>
> %users   %pkts   path used
>   7%          3%       RELAY or WIDE only
> 35%        27%      RELAY,WIDE or WIDE,WIDE
> 26%        50%      RELAY,WIDE,WIDE or WIDE,WIDE,WIDE
> 14%          5%      WIDE2-2
> 24%         10%     WIDE3-3
>   3%           7%     WIDE4-4
>
> Notice that one fourth of the users are responsible for HALF
> of all packets.  They are using the very inefficient W,W,W
> or R,W,W path.  We must get away from this kind of path
> in APRS.
>
> What is immportant above is the ratio of packets to the
> number of users of a given path.  The paths with the
> smallest ratio of packets per user is, of course, more efficient.
> Re-arranging the table from most efficient to least is revealing:
>
> %Users  %pckts  Factor  Path
> 14%          5%      2.8    WIDE2-2
> 24%         10%     2.4   WIDE3-3
>   7%           3%    2.3    WIDE
> 35%         27%    1.2    WIDE,WIDE
> 26%         50%     0.5   WIDE,WIDE,WIDE
>   3%           7%     0.4    WIDE4-4
>
> Notice the factor column.  W2-2 is almost 3 times more efficient
> than W,W.  W3-3 is 5 times more efficient than W,W,W!
>
> Now compare the New n-N Paradigm receommendation of
> W2-2 to the most common east coast W,W,W and the factor
> is a SIX TIMES REDUCTION in volume of packets.  Imagine how
> much more reliable our network can be if it efficiency improved
> by a factor of SIX!
>
> Lets DO IT.  Use WIDE2-2 in WIDEn-N areas and SS2-2 in
> states moving to the SSn-N scheme.
>
> Lets move out on the New n-N Paradigm NOW.
>
> de WB4APR, Bob
>
>
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