INTRODUCING APRS 2009Automatic Packet Reporting System

APRSWhat is it?

Designed in the late 1980’s. It was designed to marry RF traffic with what, at the time, was the comparable bandwidth available on the POTS (Plain Old Telephone System).

With the expansion of the Internet and the capabilities associated with it, the concepts have grown to accommodate more, faster information exchange.

APRSWhat is it?

• Automatic Packet Reporting System

• Original specification did not include GPS

• Original concept was primarily a way to show “objects” and “messages” (text messaging before people knew what text messaging was).

APRSWhat is it?

• Tactical• Reliable • Consistent

For more info, contact Spencer Hamons via the BARK website at http://al7yk.org or my personal blog at http://itpodcast.org/blog

TACTICAL

APRSTactical

• Messages

• Maps

• Situational Awareness23 DigiPeaters in

Range of this radio8 Active Weather Broadcast Stations

in Range of this radio

2 Mobile Radios in Range of this radio

7 Objects31 Kenwood Radios in Range

9 Messages to this user received

7 Messages from this user transmitted6 Messages have not been replied to yet

APRSTactical - Continued

• Nested Menus

12 APRS Stations, their frequencies and / or callsigns

The last time the station was heard

Frequency the station was on

What about maps?

• GPS Capabilities Added in 1992

• 1992 Capabilities were “local” only and DOS

• Internet Capabilities Increased

• Graphics Capabilities Increased

• Today, abundance of bandwidth

• Abundance of processing power

• Real-time global awareness

How is GeoTracking Tactical?• Position tracking in itself is not “tactical”

• It is the combination of real-time information related to tracked objects that provides the tactical information important to operations.

APRSTactical - Continued

• What are these “objects”?• Objects can be defined by any user on the network. Common use of objects are:

• Rally Points for Search and Rescue Operations

• Real-time weather events such as tornadoes or snowstorms

• Non HAM users on the network such as marathon runners, bicycle racers, hot air balloons, or even dog sleds.

• Meeting locations

APRSTactical - Continued

• Simple but effective bulletin board operations• Can be displayed on computer, or radio display• Potentially useful in our environment for:

• Mass dispensing exercise

• K-300 checkpoint times and health checks

• SAR

RELIABILITY

How is it reliable?

Multiple Hops

Internet

Digipeater

Packet Design

Decay Algorithm

User Density

Reliability

CONSISTENCY

APRSConsistency

• Standard Message Format

• Standard Beaconing

• Standard Packet Type (AX.25)

HOW TO DO IT

How to Use APRSOption 1

Use any PC, even an old one (notice the picture above, I meant it). Put a TNC and an old radio

out there, install free APRS software like UI-View, and start sending messages, bulletin

board information and even emails between your computer and RF users around the world.

How to Use APRSOption 2

Use a radio with a GPS attached to send your position data. Some GPS units allow two-way communications between the radio and GPS

device, and will map other users and objects on the GPS screen in real-time.

How to Use APRSOption 3

Get a handheld transceiver with built in APRS capabilities. Some even have built in GPS. With this option, all you need is in one device that can

utilize most of the APRS capabilities.

How to Use APRSOption 4

You can even take that same old, nasty computer we used in example 1, add a weather station to it, and transmit weather data to the

APRS network in addition to all the other features that APRS offers

Advanced APRS Features

• AVRS – Automatic Voice Relay System• Uses IRLP and EchoLink to enable

VoIP (Voice over IP) conversations to occur.

• User can “call” another user by callsign

• AVRS engine acts as a connection agent, automatically connecting the nodes along the path to the called user

Advanced APRS FeaturesAVRS

Internet

User KL2RA requests to

talk with KL2RB

IGate / AVRS agent looks at APRS

system and finds where KL2RB is at and what Echolink

or IRLP node is connected. Agent

automatically opens link to that

node.

Remote node passes packet request for

conversation to KL2RB on radio

screen. Voice traffic passes as a normal EchoLink or IRLP

call.

Advanced APRS FeaturesEmail to Internet Address

Internet

Centralized email engine on the APRS network will route outbound messages to any Internet valid email address. Only works one-way because unlicensed users cannot “key” the transmitter and move

messages over RF network.

QUESTIONS