Our Sponsor

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Our Sponsor

• Heartland Tower
• Providing Discounted Tower Space to Amateur Radio
  Emergency Services throughout the Heartland
• NEKSUN
• Join in the fun of APRS and repeater building
  across Northeast Kansas
• www.kØham.com

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APRS YOU in NE KS
NEKSUN
kØham.com
kØsun
SUNFLOWER INTERLINK
NEKSARC
APRS
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The NEKSUN KØHAM Network
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Why We Are Here

• APRS is a powerful tool for emergency management
• Readiness requires skilled reserve of Hams
• Topeka is a key APRS network point
• Capitol is destination for traffic
• Links from Wichita, KC Lawrence

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What is APRS

• Automatic Position Reporting System
• Packet communication protocol for sharing live
  data on a network in real time
• Real time tactical communications and display
  system for emergencies and public service
  applications (APRS Spec)

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APRS Features

• Maps
• Messaging
• Objects
• Bulletins and announcements
• Weather station reporting
• DX Cluster reporting
• Internet access
• Telemetry

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History

• Invented by Bob Bruninga, WB4APR in 1992
• Devised to facilitate short haul, short duration
  data transfer conventional packet was not
  suitable

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History

• APRS for DOS was the first program
• MacAPRS WinAPRS 1994 by Sproule brothers
• UI-Viewbest support popularity
• Many other APRS apps since runs on Windows 3.x,
  9x, NT and XP, Mac, Linux, Palm, CE and DOS
• GPS adjunct came afterwards

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Uses

• Passive Fun
• Watch the display of many stations
• Watch the ISS or PCsat fly by
• Watch emergencies in action
• Tracking
• Find your buddies
• Track your teenager
• Balloons and rockets
• Meet hams spontaneously on the road

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Uses

• Telemetry
• Balloons and rockets
• Post bulletins, event notices and venues
• Send email

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More Uses

• Events
• Track the parade Grand Marshal
• Track the last marathoner or bike racer (brew to
  brew run Demo)
• Emergencies
• Search and rescue
• Disaster information
• EOC messagingm (Single Line)
• Track the fire chief

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Still More Uses

• Weather monitoring
• See wind speeds and temperatures in the area
• Report wind damage
• Track tornados

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Weather monitoring

• Users can create and move objects such as
  hurricanes and funnel clouds.
• The objects can be transmitted through the APRS
  network to the NWS
• Objects could be used to transmit attributes not
  quantifiable as a number
• Collection of data
• Trending Weather Data
• Weather Alerts from NWS
• Superimposed RADAR

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Theory

• Assumptions
• Packet radio
• Digipeaters
• APRS Protocol
• Frequencies
• GPS

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Assumptions

• Radios
• Antennas
• PC Skills

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How does APRS Work?

• Some details

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Packet Radio

• History
• AX.25 protocol was approved by ARRL in 1984
• Came from X.25 protocol (the A is for Amateur)
• Primary difference from X.25 is allowance for
  call signs and for unconnected packets

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Packet Radio

• Packets
• Strings of data bytes called frames
• 3 kinds of frames in ordinary packet
• Information (I frame)
• Supervisory (S frame)
• Unnumbered (U frame)
• 6 kinds of U frames, one is Unnumbered
  Information frame
• UI frames are used for transmitting data in an
  unconnected mode

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Packet Radio

• In packet radio, qsos are always between
  connected stations
• Several qsos can take place simultaneously on
  the same frequency
• Packet qsos may be digipeated but by specific
  stations

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How is APRS different from Packet Radio?

• Communication is one to many
• Uses generic digipeating with well-known aliases
• Supports intelligent digipeating to reduce
  network flooding
• Uses UI frames for messaging, bulletins and
  announcements
• Provides maps and other features

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How APRS uses Packets

• Uses the same AX.25 protocol but only a part of
  it
• Uses Unnumbered Information (UI) frames
  exclusively
• Always runs in connectionless mode

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How APRS uses Packets

• Frames are transmitted without expecting any
  response
• Reception is not guaranteed
• Messages work same way but use an ack technique

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The UI Packet
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Destination Address

• From the APRS spec

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Destination Address

• The adr SPCL is to be used for special events.
  APRS s/w should provide for only showing stations
  with this adr (but it doesnt).
• Usually just shows the software version. WinAPRS
  v2.6.1 sets this to APW261

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Destination Address

• May also contain
• MIC-E encoded data
• Other unique encoded data
• No reason to change this since s/w cant cope

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Source Address

• My station call sign

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An Intervening Word about Digipeaters

• Why do we need them?
• Increase coverage
• Digipeater versus repeater
• Voice repeaters operate in duplex mode
• Digipeaters operate in simplex mode
• Digipeaters use store and forward technique

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Digipeaters

• Wide area digipeaters
• In this area are usually on a tower
• Have good antennas and high power
• Operate automatically
• Operate all the time
• Have Battery Backup

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Digipeaters

• Relay digipeater
• Usually somebodys home station
• Should be able to communicate with a WIDE station
• Purpose is to help low powered stations get to
  the WIDE

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Digipeaters

• WIDE
• Examples KØHAM-14
• or not
• Examples WVØS

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Digipeaters

• Digipeaters respond to certain generic aliases
• Relay, used by any station to relay mobiles to a
  wide
• Echo, HF only, same function as Relay
• Wide, all high digipeaters (dumb)
• WideN-N, wide digipeating limited to N hops
• Trace, use call sign substitution to indicate
  path the packet took (TEST ONLY)
• WideN-N, wide digipeating limited to N hops
• Gate, HF to VHF connection

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Digipeaters

• Digipeaters only repeat if their call sign, their
  unique alias, or a generic alias is in the digi
  path
• Two Types
• UIFLOOD- WIDE3-3
• WIDE,WIDE,WIDE

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Back to the UI Packet -- Digipeater Addresses

• Also known as the unproto path
• Up to 9 addresses
• Specific or generic aliases
• Specified in s/w configuration or in the UNPROTO
  command APRS V RELAY, WIDE,WIDE
• Represents the route you want your packet to
  follow

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Digipeater Addresses

• Rules of thumb
• Dont use RELAY unless mobile
• If you can hit a wide, then include it as the
  first digi in the string
• For maximum range, add WIDE2-2 or WIDE3-3 after a
  specific DIGI
• Examples
• APRS V KØHAM-14, WIDE2-2
• APRS v RELAY, WIDE,WIDE
• APRS V WIDE3-3
• Anything MORE than 3 should be avoided!

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Digipeater Addresses

• You can be really specific about the path
• Example
• APRS V KØHAM-14, KØHAM-12, KØHAM-13 would route
  you down to Matfield Green, nowhere else

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Types of Data

• There are ten main types of APRS Data
• Position
• Direction Finding
• Objects and Items
• Weather
• Telemetry
• Messages, Bulletins and Announcements
• Queries
• Responses
• Status
• Other

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Data Example

• Position data

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Data Extension Example

• PHG extension refers to power, height and gain
  (also directivity)
• Height is above average local terrain
• Form is PHGphgd

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Frequencies

• VHF 144.39
• 1200 baud
• HF 10.15151 LSB
• 300 baud
• Satellite
• ISS Downlink 145.800, uplink 145.990
• PCsat simplex 145.828
• 1200 baud

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Getting on the Air with APRS What to
Buy/Scrounge

• Details

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Hardware

• Home station requirements
• 2 meter radio and antenna
• Desktop computer
• TNC or soundcard/interface
• Mobile station requirements
• 2 meter radio and antenna
• Variables

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Hardware

• Mobile variables Track View
• GPS
• Laptop
• TNC

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Hardware

• Mobile variables Mobile Tracking
• GPS
• Tiny Track, or Tracking TNC

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Hardware

• Mobile variables Portable tracking
• GPS
• No computer
• Tracker interface device
• Power source for portability

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Hardware

• Kantronics KPC-3
• Supports single PC Serial Port Tracker
• Supports UI Flood Protocol
• Current Version is 9.0
• Simple Mobile Operation
• Cost 189

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Hardware

• Kantronics KPC-3
• Good for Home use
• Version 8.2 Supports UI Flood Protocol
• Average cost used 80

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Hardware

• KPC-2, KAM, MFJ, others
• Good for Home use
• Low cost
• Check http//swap.qth.com/ for deals

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Hardware

• Mic-E
• A mike encoder
• Compressed Packet burst at end of transmission
• Must be supported by local repeaters (none
  currently enabled)
• Tigertronics TigerTrak TM-1 (90)
• Also functions as a full function tracking and
  telemetry module

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Hardware

• A self-contained tracking/telemetry module
• Tigertronics TigerTrak TM-1
• Tiny Trak III kit (30)
• See http//www.byonics.com/tinytrak/index.html

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Hardware

• TAPR PIC-E

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Hardware

• Computers
• Running with a TNC doesnt require a fast
  computer or recent O/S
• A slow machine means your maps will refresh very
  slo-o-o-oly
• As with all apps, more memory is better

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Hardware

• TNCs
• Any TNC will do when a computer is attached.
• Old style TNCs may not be GPS aware, but they
  work for base stations

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Hardware

• Cables
• Sources
• MFJ http//www.mfjenterprises.com

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Hardware

• TNC cables
• Computer serial port to TNC
• Unique to your TNC
• TNC to radio mike connector
• Unique to your TNC and radio

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Hardware

• Consideration for GPS with TNC
• 2 serial ports are needed (Unless KPC3)
• If only 1 serial port is available, can use a
  Port sharing device

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Hardware

• GPS Receivers
• Must have PC interface port
• Must output NMEA messages on the PC port
• Good to have an external antenna for the GPS
• RS-232 or TTL

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Software

• WinAPRS
• Pros
• Everybody knows about it
• Free maps
• Can use high quality Precision Maps
• Unregistered version has full functionality

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Software

• Cons
• Help function is bad
• Not totally stable
• Not everything works
• Maps arent so good
• Expensive to register
• Somewhat limited in scope

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Software

• APRSSA
• Pros
• Comprehensive functionality
• High quality Street Atlas maps

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Software

• Cons
• No (I said no) help
• Hard to manipulate maps
• Confusing
• Only works with Street Atlas
• Have to register to use AGWPE
• Expensive to register

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Software

• UIView
• Pros
• 16 bit version is free, 32 bit version is
  inexpensive
• Quality coding
• Extensive help files
• Any GIF or bitmap file can be a map
• Works with Street Atlas and others
• Detailed Street level Mapping with Precision Maps

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Software

• Cons
• Limited Individual Replay options

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Software

• Xastir
• Pros
• Works on Linux
• Good map capability
• Cons
• Not a Windows program

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Software

• MacAPRS
• Shares same code with WinAPRS

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Software

• APRSPoint
• Pros
• High quality MS MapPoint maps
• Cons
• Program is expensive and maps are more expensive

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Software

• My recommendation
• Use UI-View with Precision Maps 6

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Satellites

• ISS
• Excellent signal
• PCsat
• Built by Bruningas students at Annapolis
• Find the satellites position
• http//liftoff.msfc.nasa.gov/realtime/JTrack/Space
  craft.html

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Another way to view APRS

• Internet
• FINDU
• http//map.findu.com
• Struggling to find a free mapsource
• APRSWorld
• http//www.aprsworld.net
• Nice track plotting capability

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Important Links

• NEKSUN APRS http//www.k0ham.com/aprs
• Tucson Amateur Packet Radio (TAPR)
  http//www.tapr.org
• NWAPRS http//www.nwaprs.org
• http//web.usna.navy.mil/bruninga/aprs.html
• http//www.hulleng.karoo.net/g0vrm/content/aprs/di
  gi.htm
• http//www.w0ipl.com/ECom/aprs-imp.htm
• http//www.qsl.net/ve3lki/aresdec/ARESDigitalPage.
  html
• http//www.w1fn.org/fnpack/index.html
• http//www.byonics.com/pockettracker/
• http//www.byonics.com/tinytrak/index.html
• http//www.ocraces.org/powerpole.html
• http//www.kc5goi.net/aprs/digipeater.html
• http//webpages.charter.net/n4wyk/kpc3digi.htm
• http//wes.johnston.net/aprs/aprs0a.htm
• http//www.bsrg.org/aprs/aprs1.html
• http//www.bsrg.org/aprs/links.html
• http//web.usna.navy.mil/bruninga/aprs/digi-overl
  ays.html
• http//web.usna.navy.mil/bruninga/aprs/ALOHA.txt

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Questions

• ??