TH-D72A/E - N3UJJ

7 APRS NETWORKSExample 2:This is a general recommendation for permanent digipeaters installed at a high location.• DigipeatDigipeat(MyCall): On• UIdigipeatUIdigi: OnAliases: SAR(other local paths can be defined here)Note: SAR stands for “Search and Rescue”.• UIfloodUIflood: OnAlias: SS or SSSSubstitution: ID• UItraceUItrace: OnAlias: WIDE7.4.5 Proper Configuration (written by Bob Bruninga, WB4APR)New-N ParadigmIn 2004, the recommendations for APRS path configuration were drastically simplified. And this wascalled the New-N Paradigm. This plan eliminated all use of the simple paths of RELAY, WIDE andTRACE. We recommend you to avoid any references to these paths and ignore them. Instead, theNew-N Paradigm introduced three major routing paths, WIDEn-N, SSn-N and TEMPn-N. There n-Nis 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 andshould be used for routine operations. Limiting the hops to 2 hops or less assures that the packetscover the local area and region (and will get to an IGate somewhere). And at the same time thepackets do not go any farther or add unwanted interference in other areas. This drastically improvedthe efficiency and reliability of the APRS national network. The only disadvantage of the WIDEn-Nstandard was that digipeaters could only be built with specialized modern APRS TNC hardware andcould 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 earlydays of APRS we used the generic alias of “RELAY” so that any TNC or home station could be usedas 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 simplegeneric ALIAS but at the same time, be recognized by all of the modern WIDEn-N digipeaters aswell. These modern TNCs with the WIDEn-N mechanism all avoid making any duplicates. Thisallows local areas to put up small area, local coverage WIDE1-1 digipeaters using any old TNC as afirst hop for mobiles driving nearby. The mobile can hit these fill-in digis in weak signal areas but at60 CONTENTS TH-D72A/EFrom The N3UJJ.COM Document Library