IRLP: Difference between revisions

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Related wiki pages: [[Echolink]], [[D-Star]]
== IRLP - What is it? ==
== IRLP - What is it? ==


IRLP ('''I'''nternet '''R'''adio '''L'''inking '''P''')roject was created in 1997 by Dave Cameron VE7LTD with the aim of providing links, via the internet, between amateur radio installations. The key philosophy behind the project was and remains for it to provide these links so that amateurs with inexpensive transceivers, or licence classes with low power limits, had access to a worldwide network.
IRLP ('''I'''nternet '''R'''adio '''L'''inking '''P'''roject) was created in 1997 by Dave Cameron VE7LTD with the aim of providing links, via the internet, between amateur radio installations. The key philosophy behind the project was and remains for it to provide these links so that amateurs with inexpensive transceivers, or licence classes with low power limits, had access to a worldwide network.


== Hardware requirements ==
== Hardware requirements ==


A stand alone Pentium PC), with at processor speed of at least 200MHz, at least 128MB of RAM, and hard drive capacity of at least 2GB
A stand alone Pentium PC, with a processor speed of at least 200MHz, at least 128MB of RAM, and hard drive capacity of at least 2GB. This is called the node computer.


A parallel port running LPT1  
A parallel port running LPT1  
Line 16: Line 18:


Interface board. These are not construction projects, but are available from [[http://www.irlp.net the IRLP website.]]
Interface board. These are not construction projects, but are available from [[http://www.irlp.net the IRLP website.]]
The alternative to this arrangement is an "embedded node" in which the IRLP system and the OS are programmed into the flash memeory of a computer with no hard drive. These computers do not hhave a fan and come pre-loaded with all the node information as well as [http://www.echoirlp.net/ EchoIRLP]. This allows IRLP and [[Echolink]] systems to run on the same node.


== Operating System ==
== Operating System ==


IRLP runs on [http://www.centos.org CentOS], which is based on [http://www.redhat.com/rhel/ Redhat EL]. No Windows or Mac versions are available.            
IRLP runs on [http://www.centos.org CentOS], which is based on [http://www.redhat.com/rhel/ Redhat EL]. No Windows or Mac versions are available.
 
Some knowledge of command line instructions is advantageous, as there is not a GUI at time of writing.           


== RF Hardware ==
== RF Hardware ==


A radio or repeater that has COS (carrier operated squelch) capability. There are anumber of radios that are suitable for this purpose. Some of these and how to connect them can be found on [http://www.irlp.net the IRLP website.]
A radio or repeater (the node radio) that has COS (carrier operated squelch) capability. There are a number of radios that are suitable for this purpose. Information on some of these and how to connect them to the node computer can be found on [http://www.irlp.net the IRLP website.]
 
Most nodes operate in either the 2m or 70cm bands. IRLP can be run either in simplex or with split frequencies. Club owned nodes are usually attached to a repeater, whereas privately owned nodes usually are not, so run as simplex operations.
 
== How does it work? ==
 
IRLP uses a Voice-Over-IP (VoIP) software called [http://speak-freely.sourceforge.net/userguide/ar01s03.html Speak Freely]. Speak Freely runs on
[http://www.linux.org/Linux].
 
The operator connects to an IRLP node with a standard FM transceiver. Voice from the node radio is sampled using the A/D converter at the input of the node computer soundcard. The digital stream created is at 120kbs.
 
The data stream is compressed by a factor of 4 to 32kbs. This data is then broken into packets which are transmitted along a DSL connection to a remote node (using VOIP). The packets are re-joined to a data stram at 32kbs, and then decompressed back to 120kbs.
 
Finally the data stream is converted back to audio and transmitted by the remote node radio. A user at the remote end receives the audio into a standard FM transceiver.
 
A more detailed description is available at the [http://www.irlp.net IRLP site.]
 
== Where are the nodes? ==
 
IRLP nodes can be found all over the world. Perhaps the most user friendly site to find out which nodes are operating can be found [http://irlp.g4eid.co.uk/status/ here.]These pages are produced by Mark Haworth G4EID.
 
== Using IRLP with a radio ==
 
'''Step by step process'''
 
* Look either [http://status.irlp.net/ here] or [http://irlp.g4eid.co.uk/status/ here] to find out which node numbers are available and where they are located. Both these lists are updated regularly, and give information about which nodes are connected to each other.  If you use [http://earth.google.com/ Google Earth], this [http://www.irlp.net/setup-irlp.kml kmz file] will show you the connections between IRLP nodes.
 
* Locate a node close to you and one that you would like to contact. Repeater listings such as [http://ham.longlandclan.yi.org/ this one] for Australia, will provide useful information in your search.
 
* Use a DTMF microphone and dial in the node number that you wish to contact. A message will tell you if you either are successful or unsuccessful.
 
* There will be a delay between sending and receiving when using IRLP or [[Echolink]]. Best protocol is to wait a couple of seconds between hearing the other person and starting to talk yourself.
 
* When you have finished talking, use the DTMF buttons and dial in 73.  This will disconnect the nodes.


== Getting Help ==
== Getting Help ==


An active user group can be found in Yahoo Groups [http://groups.yahoo.com/group/irlp/ here.]
An active user group can be found in Yahoo Groups [http://groups.yahoo.com/group/irlp/ here.]
{{modes}}

Latest revision as of 11:06, 9 April 2009

Related wiki pages: Echolink, D-Star

IRLP - What is it?

IRLP (Internet Radio Linking Project) was created in 1997 by Dave Cameron VE7LTD with the aim of providing links, via the internet, between amateur radio installations. The key philosophy behind the project was and remains for it to provide these links so that amateurs with inexpensive transceivers, or licence classes with low power limits, had access to a worldwide network.

Hardware requirements

A stand alone Pentium PC, with a processor speed of at least 200MHz, at least 128MB of RAM, and hard drive capacity of at least 2GB. This is called the node computer.

A parallel port running LPT1

Soundcard

Ethernet port

Internet connection

Interface board. These are not construction projects, but are available from [the IRLP website.]

The alternative to this arrangement is an "embedded node" in which the IRLP system and the OS are programmed into the flash memeory of a computer with no hard drive. These computers do not hhave a fan and come pre-loaded with all the node information as well as EchoIRLP. This allows IRLP and Echolink systems to run on the same node.

Operating System

IRLP runs on CentOS, which is based on Redhat EL. No Windows or Mac versions are available.

Some knowledge of command line instructions is advantageous, as there is not a GUI at time of writing.

RF Hardware

A radio or repeater (the node radio) that has COS (carrier operated squelch) capability. There are a number of radios that are suitable for this purpose. Information on some of these and how to connect them to the node computer can be found on the IRLP website.

Most nodes operate in either the 2m or 70cm bands. IRLP can be run either in simplex or with split frequencies. Club owned nodes are usually attached to a repeater, whereas privately owned nodes usually are not, so run as simplex operations.

How does it work?

IRLP uses a Voice-Over-IP (VoIP) software called Speak Freely. Speak Freely runs on [1].

The operator connects to an IRLP node with a standard FM transceiver. Voice from the node radio is sampled using the A/D converter at the input of the node computer soundcard. The digital stream created is at 120kbs.

The data stream is compressed by a factor of 4 to 32kbs. This data is then broken into packets which are transmitted along a DSL connection to a remote node (using VOIP). The packets are re-joined to a data stram at 32kbs, and then decompressed back to 120kbs.

Finally the data stream is converted back to audio and transmitted by the remote node radio. A user at the remote end receives the audio into a standard FM transceiver.

A more detailed description is available at the IRLP site.

Where are the nodes?

IRLP nodes can be found all over the world. Perhaps the most user friendly site to find out which nodes are operating can be found here.These pages are produced by Mark Haworth G4EID.

Using IRLP with a radio

Step by step process

  • Look either here or here to find out which node numbers are available and where they are located. Both these lists are updated regularly, and give information about which nodes are connected to each other. If you use Google Earth, this kmz file will show you the connections between IRLP nodes.
  • Locate a node close to you and one that you would like to contact. Repeater listings such as this one for Australia, will provide useful information in your search.
  • Use a DTMF microphone and dial in the node number that you wish to contact. A message will tell you if you either are successful or unsuccessful.
  • There will be a delay between sending and receiving when using IRLP or Echolink. Best protocol is to wait a couple of seconds between hearing the other person and starting to talk yourself.
  • When you have finished talking, use the DTMF buttons and dial in 73. This will disconnect the nodes.

Getting Help

An active user group can be found in Yahoo Groups here.


Modes of operation
Modes CW * AM * FM * SSB * Digital * Echolink * Emission Classification * IRLP * Optical communications
Packet APRS * D-Star
SSTV and ATV SSTV frequencies * SSTV Modes