APRS: Automatic Packet Reporting SystemCHRIS MAHER – N7CPMWWW.HARBORHAM.COM

Tonight’s Activities

• Quick bio (N7CPM)

• APRS…what is it?

• APRS Uses

• APRS Devices

• Q&A / Open Forum

Quick History…N7CPM• IT Engineer/Consultant. Been interested in technology

since two years old and has worked in IT since 2002.

• Got interested in HAM Radio at 10 years old and was elmered by Bill Graham K6QB

• Got reintroduced to the hobby by Jeff KG7MPF

• Was first licensed as a Technician in July 2014, upgraded to General in October 2014

• Current Interests: APRS, CW, and wire antennas

• Been hooked ever since and show no sign of slowing down!

Disclaimer

• APRS is HUGE. As with anything in this great hobby of ours, there are many routes you can venture into and many different niches you can focus on.

• This presentation is a high-level overview with the goal of introducing APRS and helping get HAMs, ranging from those who are freshly licensed Technicians to the most seasoned Extras, on the air with APRS.

• For any technical questions, or in-depth ragchewing, please feel free to contact me at n7cpm@harborham.com

APRS…so, what is it?

Brief History• APRS was the brainchild of Bob Bruninga WB4APR. It was

originally designed for tactical communications, with the goal of sharing information quickly within a specific area

• When GPS became more and more commonplace, APRS started to become integrated with maps. This allowed for quick, visual exchanges of important information to operators in a local area

• Unlike traditional packet radio, Bob designed APRS as a multi-user data network. With its decentralized approach, APRS allows for almost universal connectivity without the complexity of a centralized system. It permits any number of stations to exchange data, as would users on a voice net

Originally Designed for Local Use• When originally designed, APRS was created with tactics in mind.

While the use of IGates and digirepeaters have allowed APRS to blossom into what it is today, its original purpose was for short distance, real-time emergency communication on RF. Especially in emergencies.

• With all of its abilities, one critical piece is at the core of APRS: tracking of key assets.

• Where is our event leader?

• Where are the emergency vehicles?

• What is the weather over there?

• Where is the EOC located?

Cave-Link Radio• Sometimes the need for APRS will take you hundreds of feet

underground!

• Mammoth Cave Test - 2 Mar 2013: ”With the support of the National Park Service, and NSS volunteers we conducted an APRS test in Mammoth Cave on 2-3 March 2013. The test was conducted by WB4APR, KG4LVA, KY4JME, KJ4AJP, and KG4CSQ under the care of Ranger Rick Toomey and NSS member Gary Gibula and others. We fielded 8 boxed TMD700/710 radios and 5 THD72 handhelds for relay plus several other D7 walkie talkies for communications. We also carried FRS radios for short range voice communications with unlicensed volunteers. After a few hours of debugging, the test was successful in extending the data link the entire 1 mile length from the elevator to the Carmichael entrance. KG4LVA manned a topside IGate at Ranger Headquarters and KY4JME manned an APRS station in the Snowball room below ground.” http://aprs.org/cave-link.html

Cave-Link Radio•  This system “uses the TEXT and

POSITION relay capability built into some APRS radios for extending cave radio VHF/UHF communications by 7 to 14 linear hops with no prior infrastructure. This is accomplished by placing handheld (relay capable) walkie-talkies or relay boxes along a cave passage. Communications throughout the multi-hop system can be maintained including links topside” www.aprs.org/cave-link.html

APRS is Information• Simply put, APRS is the exchange of packet data

between HAMs

• It is a two-way tactical real-time digital communications system between all assets in a network sharing information about everything going on in the local area. On ham radio, this means if something is happening now, or there is information that could be valuable to you, then it should show up on your APRS radio in your mobile. (From Bob Bruninga, WB4APR)

Isn’t APRS just an exchange of GPS data?• No! Not at all.

• While one of the primary, and most used functions of APRS is the relaying of GPS data between HAMs, there are HUNDREDS of other great uses for the system:

• Maps• Weather Station Reporting• DX Cluster Reporting• Internet Access• Messaging (including e-

mail)• Bulletins and

Announcements• Fixed Station Tracking • Object Tracking

How many people use APRS?• APRS is used by over

40,000 people worldwide

• APRS is used with HTs, Mobile Units, iPhones, Weather Stations, ISS, etc!

• Wherever you find yourself in your travels, you will most likely find yourself in range of an APRS digipeater.

APRS SSID’s 0: Fixed station w/Messaging

1-4: Generic additional stations

5: Other networks (DSTAR,etc)

6: Special Activity, Satellite ops, camping

7: HTs, misc. human portable

8: Boats, sailboats, RV’s, 2nd vehicle

9: Primary Mobile (w/Messaging)

10: Internet,Igates,echolink,etc

11: Balloons, aircraft, spacecraft

12: APRStt,DTMF,RFID,devices, one way devices

13: Weather Stations

14: Truckers or full-time drivers

15: Generic additional station, digi, mobile, wx, etc

Igates, Digipeater, APRS Paths

IGATES

• Stations that listen for APRS traffic and relay it to the Internet• Ideal:• 1 IGate for every 30 miles of

coverage; 1 backup IGate • Too many IGates is actually a

bad thing

• APRS is not dependent on IGates to work

SIMPLE HOME IGATE SETUP

Igates, Digipeater, APRS Paths

DIGIPEATER

• Especially when running mobile, it can be difficult to tell if your signal is being received. For this reason, digipeaters are used to relay your signal

• Two types:• Relay Station • Relays APRS message to Wide Digipeater

• Wide Digipeater • Sparse , much like Igates• Send data over large distances, over

cities or across the state

APRS PATHS

• Example: Relay,WIDE3-3• Relay by first station that hears it,

rebroadcast to WIDE digipeater, forward for 3 more WIDE digipeater hops

• WIDE1-1 (Local Communications)

• WIDE2-2(Metro Wide Communications) Most common

• WIDE3-3(Interstate Communications) Rare

APRS Features: Messaging• With APRS, HAMs can

communicate with each other using a special messaging feature

• This allows for a quick exchange of information, much like a text message on your phone.

• This is very helpful for regional communication or for emergencies

How to get started with APRS

A Few Routes to TakeTRADITIONAL MORE EXPENSIVE/EASY TO USE

NEWER, LESS TRADITIONAL CHEAPER/LEARNING CURVE

APRS Ready HTs• Yaesu VX-8GR

• TH-D72A

• Icom ID-51A D-STAR(D-PRS)*

D-PRS is the act of converting Icom GPS information generated by Icom D-STAR radios in GPS mode into TNC2 formatted APRS strings. It is important to note that D-PRS is not a protocol but a conversion specification.

APRS Ready Mobile Transceivers

• Kenwood TM-D710G ($639.95 HRO)• “Gold Standard” for APRS

mobile units

• Does not have its own GPS, must be connected to an external GPS device

• Yaesu FTM-400DR ($599.95 HRO)• Newer entry to the market,

slightly less expensive than Kenwood

• Has build in GPS, so no additional units are needed

Getting started with APRS for cheap

Mobilinkd TNC2

• The Mobilinkd TNC2 is a fully functional, Bluetooth connected TNC (Terminal Node Controller)

• At about the size as a pack of gum, the TNC2 is extremely portable.

• To get started with the TNC2, all you need is an Android device (phone/tablet) or Linux/Windows computer with Bluetooth capabilities

• “ One cable connects this 1200 baud TNC to the radio.  Connect to your favorite software on your mobile device, such as APRSdroidor APRSISCE/32.  It will work with any packet software that speaks the KISS protocol.” www.mobilinkd.com

www.mobilinkd.com

Portable • Love them, or hate them, we are all familiar with the

$40 Baofeng radios.

• With the addition of the TNC2, your $40 Baofeng (or other brand FM Transceiver) now has TNC capabilities as good or better than many $400+ HTs!

• APRS Droid can run on your Android phone and work just fine, just as long as you are in range of the Bluetooth connection

Mobile• With the TNC2, it is really easy to get your mobile radio

connected. Many mobile radios support data connections. For example, the Kenwood V71a has a miniDIN 6-pin input for data. A simple cable connects this radio to the TNC2.

• Other radios need to use sound for transmitting (VOX) and receiving

• Going this route takes a bit more tinkering, but allows you to use more affordable mobile transceivers with APRS. N7CPM’s Kenwood V71a works really well for this!

N7CPM’s APRS Setup

MOBILE

• Mobilinkd TNC2 Bluetooth TNC with MiniDIN-6 TNC Cable

• Kenwood V71A Dual band Transceiver

• Samsung Galaxy 10.1 Tablet running Android OS

N7CPM’s APRS Setup

PORTABLE

• Mobilinkd TNC2 Bluetooth TNC with TNC Cable for Kenwood, Wouxun, Baofeng ($65)

• Baofeng BF-F8HP ($45)

• LG Revolution Phone (old Android phone from 2011) ($25)

• Total Cost: $135 (from scratch)

APRS-IS: Get on APRS Today!• Automatic Packet Reporting System-Internet Service

• APRS-IS is the system which connects many APRS radio networks throughout the world.

• Allows HAMs to use APRS without the need for a radio (you must be a licensed HAM to gain access to this)

• APRS-IS is supported on Android (APRSdroid) and iOS (PocketPacket)

• To get started, you first need a passcode, unique to your call. This can be obtained at http://apps.magicbug.co.uk/passcode/

APRSdroid• www.aprsdroid.org

• Open source, feature packed APRS application for Android devices

• Can be used with Mobilinkd TNC2 (KISS Protocol)

• See other APRS stations around you, send/receive messages over APRS, view maps and see where stations are around you

• Also supports APRS-IS

PocketPacket• http://koomasi.com/pocketpacket/ or on the App Store

• PocketPacket is an APRS client for iOS.

• PocketPacket incorporates a software-based TNC, allowing you to directly capture and visualize, or encode and transmit 1200 baud packets (AFSK modulation) using a VHF radio transceiver. With PocketPacket you can also get and send packets over the Internet, by selecting one of the available Tier 2 servers of the global APRS-IS network.

• Incoming data is presented on a map, as most packets define some object, with a specific symbol and location. By selecting a symbol, you can view the latest information sent for the corresponding object, as well as the raw packets that produced it. All available objects are also shown in a list, which allows you to search for the ones you are looking for. Messages and bulletins are shown in a separate set of screens, structured like an e-mail client.

APRS.FI – Your new best friend

APRS.FI – Mobile Enabled• APRS.FI works on your

phone too.

• This is a screenshot I took when Jeff (KG7MPF) and I were at our Field Day location in Central Washington.

Questions/Comments

APRS: Automatic Packet Reporting SystemCHRIS MAHER – N7CPMWWW.HARBORHAM.COM