2. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Configuring APRS Digipeaters in 2005 Rev 1 Presented by Ken Isom kd5aia@arrl.net Most slides from “Intro to APRS Digipeaters” by Rich Casey, N5CSU and “Intro to APRS” by John Beadles, N5OOM

3. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Goals APRS brief overview APRS configurations APRS improvements and latest guidelines APRS hardware example APRS KPC3 TNC specifics APRS DFW APRS Questions from the Floor APRS Resources and Final Suggestions

4. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 What is APRS? APRS, or Amateur Position Reporting System, developed by Bob Bruninga, WB4APR is a system that allows users to transmit location and other data in single data packets. Usually stations being tracked use GPS receivers to provide real time tracking data. APRS uses existing packet TNCs (terminal node controllers) and small, low cost microcontroller driven units to transmit standard AX.25 packets on a ground frequency (in the U.S.) of 144.39 at 1200 baud. APRS can also be used over HF and satellite links. Let’s listen…

5. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 APRS Applications Public Service Events –Bike rallies –Parades –Crime prevention patrols Other –Weather Stations –Repeater advertising –Event talk-in Skywarn Nets –Spotter assignment –Storm tracking Post Disaster Management –Damage assessment –Liaison tracking –Logistics management –Staging site talk in Search & Rescue

6. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 How APRS Works An APRS station broadcasts a packet of information, typically a GPS coordinate and other information. The packet is received and decoded by stations in range. Digipeater stations hear the packet and rebroadcast it based on – rules in the digipeater software and – commands that you put in the packet.

7. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Problems with APRS APRS on VHF is a single 1200 baud shared channel. APRS packets take a finite amount of time to transmit; therefore, only a limited number of users may operate in a given area. The number of digipeaters that retransmit a packet is dependent on how each user configures his TNC. Misconfiguring a TNC can flood the channel. Smart digipeating can help. More on this later. Let’s listen again…

8. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Example (1) – Mobile Station Beacons Step 1. An APRS station beacons and is heard by every other APRS station in direct range

9. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Example (2) – Local Digipeater relays Step 2. The packet is rebroadcast by the local digipeater; this packet is heard by everyone in direct range of that digipeater. It is also received by other area digipeaters.

10. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Example (3) – Area digipeaters relay Step 3. The packet is then rebroadcast by the other area digipeaters. The packet is heard by every APRS station in direct range of this second set of digipeaters, including the original digipeater. I-GATE

11. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Good, Bad & Ugly The Good News: –Almost anyone can be a digipeater! The Bad News: –Almost anyone can be a digipeater! The Ugly News: –Lots of Digipeaters out there with problems Distorted levels, Hum/Noise, Can’t Hear well, Can’t Transmit very far, not adding Value

12. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Why do you want a digipeater ? In the olden days Amateur Radio wanted EVERYONE to have a digipeater to fill in. “I have this old TNC and want to get some use out of it “ Now it is prudent to ask if one is actually needed at your location and the reasons or if another approach might be better. Your new Digi might help or it could hurt the existing network by overloading Many Digi’s are LID’s and only pollute the airwaves and cause lost packets and do not add value to the system. Regional or Mobile Digipeaters for specific functions or events may be the answer. Want to start a great discussion? Should Certain Events operate on 144.390 ? Do you have a 5 watt APRS and you want to cover 100 miles? Well, that may or may not work as well as you think. You might can hear some of the signals out there but you probably wont hear most of them and that results in lost packets when you get stepped on. Big Problem. Remember two other Amateur’s rules: “We must share the limited airwaves” “ Why spend my money on something if I don’t work or isn’t needed?” Hear any Doubles ?

13. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Before Deploying APRS Listen, Listen, Listen Monitoring doesn’t hurt anyone….. and its cheaper too. Speaker plug to TNC or PC and you’ll get the feel. Discuss local needs and guidelines with existing APRS groups to ensure interoperability. Decide what your going to do with your APRS tool. Your hardware might serve better if it is installed somewhere else.. Grandma’s house, local business building, water tower etc. Again, check with local groups who know the holes in the system. Be a teamplayer and keep your unit in tip-top shape.

14. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Digipeaters: two flavors Relay (deprecated – now WIDE1-1) –A default alias that all stations share. We’re all relays but this is unnecessary in urban areas with good wides! Wide (deprecated – now WIDEn-n) –Exceptional stations… coordinated with area hams to provide specific wide area coverage

15. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Public Internet Digipeater C Rural APRS-IS Server Example (4) – Outside Area - Rural digipeaters may have different goals ISSUE: In Rural areas or along long stretches of highway, low-power and mobile units don’t make it back to Urban areas or into I-GATEs. Intersection of I-45 and Texas Hwy 287. May only receive within 5 miles but transmits 25 miles mostly in one direction. Use Yagi to hit W5DCR downtown Dallas. I-GATE 30 miles Ennis Tx Low trafficHigh traffic

16. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Cheap ( A Ham’s watchword) Old MFJ TNC $20 Old Wilson/Regency 20w VHF Radio $30 Old Astron 12v PS $25 Homemade Antenna $ 5 UIDigi ROM $10 Used Existing Tower $ 0 Coax and cables $10 –TOTAL $100 Bad

17. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Every Digi Site has different Goals Not very high 3 Element Yagi !?!?! Back up for Skywarn ROM based 4.0 miles southwest of Ennis, TX --- Report received 1 minutes 36 seconds ago Status: Ennis, TX Ellis Co UIDIGI 1.8b6 Raw packet: KD5AIA-7>APZ186,W5DCR-3*,WIDE,qAO,N5API-4:!3216.32N/09638.33W #PHG4100/WRT-WIDEn TX Ennis, TX kd5aia@arrl.net

18. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Environmental Considerations Winter/Summer Ferris Dump.. Dallas Trash getting taller every day ManMade Obstacles “ I could always hit the 88 Machine from here “

19. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 More about WIDES! Wide area digipeaters need to be coordinated with the user community As your network grows, a wide may need to become a relay if it will improve the network. –A good relay is hard to find! Moving from wide to relay shows the network is getting better! Example: The Dallas County experience

20. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Avoiding the ping-pong With a via address of WIDE1-1,WIDE2-1, your signal will be repeated twice –First relay (or wide) that hears you –First wide that then hears you repeats you But what if someone uses wide-wide-wide? –In the old days, you could ping, pong back and forth between digis

21. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Digipeaters: A Smarter Way Based on discussion on the TAPR APRSSIG mailing list Works best the more stations that do it Callsign substitution on retransmission –Digipeater replaces the WIDE1-1 with its callsign –Available in most TNCs –Eliminates dupes Widen-n the next step –Shorter user packets and smarter digipeaters

22. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Decoding Widen-n Widen-n –First N= total number to digipeat –Second N + number left to go Example: –N5csu-7>APT310,relay,wide2-2: retransmit via one relay and 2 wides –N5csu-7>APT310,W5DCR,wide2-1 in transit.. one wide down and looking for another!

23. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 How does Widen-n work? A widen-n digi simply repeats any packet with the via address of widen-n; but ONLY ONCE. It keeps a copy (or checksum) of the last 30 seconds of packets, and compares each new packet that it hears with these last ones to avoid dupes. This eliminates the multiple looping of packets caused by multiple generic paths such as WIDE,WIDE,WIDE when call sign substituting digis are not used (as many as 21 copies!) In a widen-n network, however, there would only be three packets. –From digis.txt file in the APRS DOS SW by WB4APR

24. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Options for Wide Area Digis KPC-3 or KPC-3+ PacComm ROM in any TAPR-2 clone tnc DIGI_NED software on any clone PC UIDIGI ROM in a TAPR-2 tnc (example shown)

25. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Wide Area Digipeater Settings Set aliases to digipeat on WIDE1-1, WIDE2-1, WIDE2-2 Use TNC that provides callsign substitution and provides widen-n function Set your POSIT power-height-gain correctly Watch your network for possible changes KPC users: turn ID to off (not needed and disrupts first digi identifier) ref: http://www.ew.usna.edu/~bruninga/aprs/id-noid.txt

26. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 2005 TNC Settings for KPC-3 (page 1) 8BITCONV ON AUTOLF ON AX25L2V2 ON AXDELAY 0 AXHANG 0 BEACON EVERY 0 BKONDEL ON BLT 1 EVERY 00:09:30 BLT 2 EVERY 00:00:00 BLT 3 EVERY 00:00:00 BLT 4 EVERY 00:00:00 BREAK OFF BTEXT BUDLIST OFF NONE CANLINE $18 CANPAC $19 CD SOFTWARE CHECK 0 CMDTIME 1 CMSG DISC

27. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 2005 TNC Settings for KPC-3 (page 2) COMMAND $03 CONLIST OFF NONE CONMODE CONVERS CONOK OFF CONPERM OFF CPACTIME OFF CR ON CRSUP OFF CSTAMP OFF CTEXT No operator here; routing to PBBS... CTRL A OFF CTRL B OFF CWID EVERY 0 CWIDTEXT DE W5MRC DAYSTR mm/dd/yy hh:mm:ss DAMA OFF DAMACHCK 18 DBLDISC OFF DELETE $08 DIGIPEAT UIONLY

28. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 2005 TNC Settings for KPC-3 (page 3) DWAIT 0 ECHO ON ESCAPE OFF FLOW OFF FILTER OFF FRACK 4 FULLDUP OFF GPSINIT GPSHEAD 1 GPSHEAD 2 GPSHEAD 3 GPSHEAD 4 GPSPORT 0 NORMAL CHECKSUM HBAUD 1200 HEADERLN OFF HID OFF HTEXT INTFACE TERMINAL LEDS ON LCOK ON

29. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 2005 TNC Settings for KPC-3 (page 4) LFADD ON LFSUP OFF LLIST OFF NONE LT 1 !3317.02NN09634.37W#PHG5530 Collin Cty Wide Digi /A=000680 LT 2 !3317.02NN09634.37W#PHG5530 Collin Cty Wide Digi /A=000680 LT 3 !3317.02NN09634.37W#PHG5530 Collin Cty Wide Digi /A=000680 LT 4 !3317.02NN09634.37W#PHG5530 Collin Cty Wide Digi /A=000680 LTP 1 APN390 LTP 2 APN390 LTP 3 APN390 LTP 4 APN390 LTRACK 0 MONITOR OFF MALL OFF MAXFRAME 4 MAXUSERS 1 MBEACON OFF MCON OFF MCOM OFF MHEADER OFF

30. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 2005 TNC Settings for KPC-3 (page 5) MRESP OFF MRPT OFF MSTAMP OFF MXMIT OFF MYCALL W5MRC-15 MYALIAS MYDROP 0 MYNODE W5MRC-15 MYPBBS NOPBBS MYREMOTE W5MRC-10 NDWILD OFF NEWMODE OFF NOMODE OFF NTEXT NUMNODES 0 PACLEN 0 PACTIME AFTER 10 PASS $16 PASSALL OFF PBBS 0

31. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 2005 TNC Settings for KPC-3 (page 6) PBFORWRD NONE EVERY 0 PBHEADER ON PBHOLD ON PBKILLFW OFF PBLIST OFF NONE PBLO NEW VARIABLE PBPERSON OFF PBREVERS OFF PERSIST 0 PID OFF PMODE CMD PTEXT REDISPLA $12 RELINK OFF RETRY 10 RING ON RNRTIME 0 RTEXT Your Password Here SCREENL 0 SENDPAC $0D

32. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 2005 TNC Settings for KPC-3 (page 7) SLOTTIME 0 START $11 STOP $13 STREAMSW $7C STREAMCA OFF STREAMEV OFF SUPLIST SWP 17,17,108 TELEMTRY 0 TRACE OFF TRFLOW OFF TRIES 10 TXDELAY 30 TXFLOW OFF UNPROTO APKPC3 VIA WIDE UIDIGI ON RELAY,WIDE1-1,WIDE2-1,WIDE2-2 UIDUPE 30 UIDWAIT OFF UIFLOOD NONE,30, ID UITRACE NONE,30

33. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 2005 TNC Settings for KPC-3 (page 8) USERS 1 XFLOW OFF XKCHKSUM OFF XKPOLLED OFF XMITLVL 100 XMITOK ON XOFF $13 XON $11

34. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Recommendations: Home QTH For your own station, set via with real callsigns, not relay,wide In an urban area with a busy channel, consider turning your own digipeat function off. If stations can see a wide, save your transmitter and the channel’s throughput! If your station is enabled as a relay digipeater, use a tnc that provides callsign substitution

35. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Best Resources for Info digis.txt file in the APRS DOS software by WB4APR Ongoing discussions on the TAPR SIGs www.tapr.org Local discussion boards –TX APRS Yahoo group: http://groups.yahoo.com/group/ntx_aprs_ug/ –www.dfwaprs.net

36. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Wrap-up Help is sitting next to you Know your area coverage Establish goals for your Digi Use latest guidelines Minimize excessive traffic Automate and backup if possible Research before spending one dollar Spread the APRS Benefits message to others

37. APRS is a registered trademark Bob Bruninga, WB4APR Copyright © 2004 – John Beadles, N5OOM All Rights Reserved Hamcom 2005 Go forth and digipeat