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  • Steve Daniels
    I am still seeing lots of TRACE paths so please spread the word The New-EU WIDEn-N Paradigm 19 March 2006 ... WB4APR Updated 25
    Message 1 of 1 , Dec 27, 2011
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      I am still seeing lots of TRACE paths so please spread the word

      The New-EU WIDEn-N Paradigm                              19 March 2006
      ----------------------------------------------------------------------
                                                                      WB4APR
      Updated 25 Nov 08 because the New-N paradigm was adopted 20 Nov 08 at 
      the final plenary of the Cavtat-IARU-Region 1 conference based on the 
      proposal of the norwegian NRLL (paper C5-33, one worldwide aprs-
      standard).  The paper C5_09 of the Danish Radio Society (european- 
      aprs-standard) has been withdrawn by the EDR.
        
      Updated 3 July 2006
      Updated 21 Sept 2006 
        
      The APRS network in
       Europe in many areas is unreliable due to the same
      lack of consistent user settings and network digipeater settings that 
      had evolved in the
       USA forcing us to finally implement the New-N
      Paradigm and get consistency and traceability throughtout the network.
      See the map on www.aprs.org/newN/NewEU-map.GIF 
        
      The following history of APRS paths is important to understand:
        
      RELAY    was simple digipeating but NO dupe checking
      WIDE     was simple digipeating but NO dupe checking*
      TRACE    simple digipeating but with call substitution & no dupe ck*
      WIDEn-N  was N flooding with DUPE-CHECKING, but no traceability
      TRACEn-N was
       N TRACEing with DUPE-CHECKING and with TRACEABLITY.
        
      For Optimum operation, APRS networks need n-N Hopping, Dupe Checking 
      and path Traceing.
        
      To eliminate huge numbers of dupes, the first step is to eliminate
      RELAY, and WIDE and TRACE paths.  Next we needed to get n-N hopping 
      and Traceing at the same time.  Since 90% of all users were already 
      using WIDEn-N, and since it is extremely difficult to get tens of 
      thousands of users to change their habbits, it was clear that there 
      was only once answer.  That is, to move WIDEn-N support over to the 
      Traceable parameter and eliminate TRACEn-N.
        
      Doing it this way, had no impact on the users at all.  And only
      the digipeaters had to change.  And the change could be done
      one-at-a-time with no impact on users.  Slowly the system would
      become one universal standard "WIDEn-N" everywhere and fully 
      Traceable at the same time.
        
      Since we had to change the parameters at ALL the digis to get rid
      of RELAY, WIDE and TRACE anyway, it was just as easy to implement
      number 2 above.  Once we put WIDEn-N into the fully-traceable 
      UITRACE function, then there was no need for the "TRACEn-N"
      any longer.  So this then left UIFLOOD unused.  So we put the STATE
      or LOCAL or REGIONAL alias of SSn-N in its place so that the 
      "untraceable" UIFLOOD parameter would still be useful without
      adding QRM out of the area.  In
       Europe these regions are based on
      a combination of two iso-standards, ISO 3166-1 country code and 
      ISO 3166-2 subdivision code.
        
      The New-N paradigm in the
       USA achievend a two to four-fold reduction
      in dupes and QRM in some regions that had been heavily using the old
      RELAY and WIDE parameters.  This improvement was striking!
        
      NOTE:  Admittedly, most European digipeaters evolved after the
       USA , 
      and so many of them did not have the bad DUPE problem of the old
      RELAY, WIDE and TRACE because they used more software based TNC's
      and digipeaters that used the better dupe-checking algorithms
      that had evloved at that point.  But still, there simply is no
      reason any longer to support all of these original legacy paths.
      Lets SIMPLIFY APRS!  Everything is obsolete except:
        
      WIDEn-N with full dupe-checking and Traceability.
        
      On 20 November 2008,
       Europe finally decided it was easier to change
      the digis to Traceable WIDEn-N than to try to convince all the users
      to change their PATHS to TRACEn-N.  At this point, there is no 
      longer any New-EU-Paradigm, as it is now a global New-N Paradigm.
        
      BACKGROUND DATA:  To asses the situation a 24 hour snapshot of 
      94,000 packets was taken in
       Europe on 17 March 2006 (did not 
      include data from the
       UK ).  The data showed the following 
      percentages of those using paths of WIDEn-N or TRACEn-N.  It turns 
      out, this was only about half of all paths!  The rest were using 
      the obsolete paths of RELAY and WIDE and TRACE!  Here were the
      numbers using WIDEn-N.
        
      WIDE7-7    18%        TRACE7-7  9%
      WIDE6-6     2%        TRACE6-6  3%
      WIDE5-5    10%        TRACE5-5  4%
      WIDE4-4     5%        TRACE4-4  1%
      WIDE3-3    36%        TRACE3-3  5%
      WIDE2-2    12%        TRACE2-2  1%
      WIDE1-1     2%        TRACE1-1  0%
      Using both WIDEn-N & TRACEn-N!  5%
        
      The numbers for the
       UK were similar but they showed a 4:1 preference 
      for using the TRACEn-N system so that they have packet traceability.
        
      The GOOD news:  Clearly WIDEn-N was favored *and* about half  of the 
      users were being considerate and keeping their QRM down with 3-3 and 
      2-2 packets.  Also this showed that simplifying the network to only 
      use WIDEn-N could be done with little impact to existing users.  And 
      simply swapping the WIDEn-N support over to the UITRACE parameter 
      would allow all WIDEn-N paths to be traceable just like we did in 
      the
       USA .
        
      The BAD news:  The biggest LOAD, however, was caused by the huge 
      numbers of 7-7 and 5-5 packets and packets with BOTH WIDEn-N and 
      TRACEn-N in the same packet!  For each of these additional hops, 
      the number of QRM copies can triple!  And for only a few 7-7 
      users, they can cause QRM over much of the continent.
        
      Our final suggestion for the New-EU Paradigm was:
        
      1) The best path for fixed stations is WIDEn-N (small N, 2 or less)
      2) The best path for Mobiles is WIDE1-1,WIDEn-N (Small N, 2 or less)
      3) Educate users to use routine N no larger than their ALOHA area
      4) Change the digis (swap TRACEn-N and WIDEn-N) so Wn-N is traceable.
        
      IGATE RULES:  IGates are also big contributors to the health of the
      APRS network.  They should set their path to their local area only 
      (usually one hop, WIDE1-1) and should not flood their area with 
      unwanted QRM. 
        
      New-N Paradigm DIGIPEATER RULES:
      1) In saturated areas, TRAP large values of N-N by setting call-
         substitution aliases of WIDE7-7, 6-6, 5-5, etc.   These will 
         digi once and then stop further routing.
        
      2) Home stations should *not* be digipeaters UNLESS:
          a) Station is high and is -not- covered by a BIG digi.
             They should  support WIDEn-N, and regional SSn-N.
          b) -or- Station is needed for a fill-in digi for nearby
              mobiles who cannot be heard by the big digi.
              Support ***only*** the WIDE1-1 alias.
        
      3) For NETWORK reliability, All digipeaters  should:
           a) Put their PHGxxxx in their position comment
           b) Put "Wn, SSSSn" in the beacon to show users propoer settings
           c) The SSn shows what regional SSSSn-N they support
           d) Use the DIGI symbol with "S" overlay to show it is new-N Paradigm.
           d) -or- use the "1" overlay for WIDE1-1 ONLY home digis.
        
      4) Move WIDEN-N support to the UITRACE parameter so
          that all WIDEn-N traffic is traceable.
        
      5) Support for WIDE, TRACE or TRACEn-N should be eliminated 
          immediately to force users to reset their settings.  Providing
          an ongoing crutch for a period will only delay the problem.
        
      6) With time, WIDEn-N will become fully traceable as DIGI
          owners move WIDEn-N support over to the UITRACE parameter.
        
      7) Digipeaters should not beacon beyond 2 hops.  Use the proportional
          pathing algorithm for DIGI beacons.  That is, set for a local
          (direct, no hops) beacon rate of 10 minutes.  If poosible, then
          also a one-hop beacon once every 30 minutes.  THen a 2-hop beacon 
          once an hour.
        
      TRACKERS:  All future mobile GPS tracker designs should consider
      the Proportinal-Pathing algorithm that sends 1 minute updates
      local-direct, every 2nd minute via one hop, every 4th minute
      via 2 hops and optionally every 8th minute via 3 hops.  See
      www.aprs.org/newN/ProportionalPathing.txt
        
      TIPS:
        
      - Be sure all digis transmit their PHGxxxx and "Wn, SSSn" data
        
      - Use the UI-PHG add-on to see the range and coverage of
        all digipeaters and stations in your area
        
      - Use UI-ALOHA add-on to see the ALOHA range for your UIVIEW
         station.  It analyses traffic heard by your station to compute
         that area that is a 100% saturated 1200 baud APRS channel.  
         Keep your N hops within that area.
        
      By simplifying the network to only WIDEn-N and WIDE1-1,WIDEn-N
      guidance and telling users to limit their N's to the minimum
      needed in their area, then a vast impovement in reliability
      and throughput can be achieved in the European System.
        
      For more in-depth understanding, please review the details
      in the web page:
        
      www.aprs.org/fix14439.html
        
      Good luck!
      Spread the word.
        
      de Wb4APR, Bob

       

       

      Steve Daniels

      G6UIM

      Torbay Freecycle Moderator

       

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