IRLP AND D-STAR OPERATION

THIS IS AN ARTICLE ABOUT INTERNET RADIO LINKING PROJECT (IRLP) & DIGITAL SMART TECHNOLOGY FOR AMATEUR RADIO (D-DSTAR) OPERATING USING SIMPLE VHF / UHF TRANSCEIVERS.

22 Apr 2009

IRLP was conceived in the late 1990's by David Cameron, VE7LTD.
IRLP is designed as a secure, robust and very flexible Internet linking system. Unlike most other systems, it is designed to prevent direct access to linked systems from the Internet. At the node level, The only way to access IRLP is via a connected radio gateway, or node as they are known.
IRLP connections are initiated by the end user by keying DTMF commends from their radio. These commands allow control of link connection and disconnection, as well as any other extra facilities added by the local node owner. IRLP offers both point to point and "reflector" (IRLP speak for a conference room) connections. To maximise control of the radio, IRLP uses an interface board between the computer and radio to pass COS, PTT and DTMF signals.
Unlike other Internet linking systems, IRLP runs under Linux, which gives it extreme stability. In fact, ISP and repeater problems are more common than node failures. The use of the Linux platform also offers a number of other benefits to node owners, such as automatic updates of both the operating system and IRLP software (no more downloading the latest and greatest, you already have it!), and a very high degree of customisation. Many IRLP node owners have written and shared scripts which do things from reporting whether a link is up or not, to a talking clock, to on demand weather beacons, random node callers, news broadcasts and parrot repeaters. There are even scripts which allow node owners who are on modems to dial their Internet connection if it goes down, by remote DTMF control! As for the IRLP software itself, it is constantly under development and there are frequent enhancements, which are released to the IRLP community via the automatic update mechanisms discussed above. I have developed experimental control scripts to allow node owners to choose from a wide array of codecs to suit a specific situation and allow users on remote nodes to trigger scripts via DTMF commands. These are examples of the extreme flexibility available with IRLP.
For those prospective node owners nervous about taking the Linux plunge, there is excellent support from the IRLP installation team and the general community of over 600 node owners. Everyone else need not worry about the Linux issue. Your sole interface with IRLP is your DTMF keypad - nothing could be simpler than that! :-)
Some people have labelled IRLP as a "secret society". Nothing could be further from the truth. It is true that IRLP node owners are asked to refrain from discussing control specifics while linked to another node, but the node numbers themselves are available for all to see at http://status.irlp.net, and it is up to each node owner whether they want to leave their system open access or add extra access codes. On a similar note, some claim that IRLP is closed source. This is only partly true. There are a handful of binaries in the system which are closed source (but have simple interfaces and/or are well documented). However, the majority of IRLP is written in bash shell scripts, which the node owner can directly read and modify.
SWLs can also get their taste of IRLP. There are streaming audio feeds of some of the reflector traffic on the Internet, which can be monitored using Winamp or your browser.
To dispel more of the strange myths surrounding IRLP, visit http://fudbuster.vk.irlp.net.
In summary. If you want to offer a secure, stable and flexible RF only link in your area, and don't mind learning a bit along the way, then IRLP is for you.

Rules for using IRLP node
These 'Rules' have been adopted by the entire IRLP community, to ensure that you, the user, gets the most from the facilities.
If you cannot abide to these 8 simple requirements, please do not use the system.

1. ALWAYS LISTEN on the repeater first to make sure a QSO is not in progress or the system is not linked to another IRLP Node or Reflector.

2. IDENTIFY YOURSELF before sending DTMF codes and trying to use the IRLP Node.

3. LEAVE A 2-3 SECOND PAUSE BETWEEN OVERS to allow the remote node to unkey and thus reset the timeouts on the remote repeaters, and to allow other users to call in. Even if you are talking to another local amateur, if an IRLP link is active, leave longer than normal pauses. If the node is connected to a reflector, this is especially important, since there can be upwards of 30 nodes connected at once.

4. DO NOT LINK AND UNLINK A REMOTE NODE WITHOUT SAYING ANYTHING
This REALLY annoys people on the other end, and is a very good way to get yourself a BAD reputation.
If you have no intention of calling anyone, DON'T ESTABLISH A LINK!
5. USE PHONETICS when giving your callsign and name over the link.
The IRLP system is an International network, and some overseas stations are not used to understanding.You will appreciate the need for using phonetics after a few contacts with overseas stations.
6. DON'T MENTION IRLP CODES when talking to other amateurs via the IRLP system.
Most nodes around the world are open, however some nodes around the world may have local access restrictions, and need a special pre-access code to be able to use the system. If someone asks you for information regarding their local IRLP system, please tell them to find the local repeater owner, operator or club to get further information.
7. LEAVE 2-3 SECOND PAUSES BETWEEN OVERS. This is CRUCIAL to the smooth operation of the IRLP network.
8. LEAVE PAUSES. its important!
Operating the IRLP node
The Internet Radio Linking Project is very easy and intuitive to use, the system gives messages about each action. When you link, when you unlink, when the node you are calling is busy, in use, or offline etc. Please make sure you listen carefully to the voice prompts so you know what is happening.
To use the system you need a radio with DTMF capabilities, and you need to have a good signal into the repeater. Once you have met these requirements you are nearly set to go. Your next step is to listen to the repeater for a while get into the swing of how the system works.
To find the Node number of a particular IRLP node, check the IRLP status page. Every node is listed here, with its node number.
If you are wanting to call an Echolink node, the node numbers can be found on the Echolink status page.
To call an Echolink node, you must prefix the Echolink node number with a star (*)
ALWAYS before speaking or transmitting please LISTEN to ensure the system is not in use.
If nobody appears to be using the repeater, check the current link status by sending DTMF #0.
This will announce whether the node is currently connected to another station, Idle, or Offline.

If the node is linked, and nobody is using it, you can bring it down by sending DTMF 73

Announce your callsign followed by the DTMF digits for the node you are calling.
This will bring up an IRLP link. Once the link has been established, call as you normally would over the repeater. It's not HF, so there is no need to put out a long winded CQ call !

DTMF 73 is used to bring down the link once you have finished your QSO.
After bringing down the link, please announce your callsign.

Here are some useful links for IRLP information on the Web:

http://www.qsl.net/vk3jed/linkcomp.html

http://www.irlp.net/

http://status.irlp.net/index.php

http://wagga.radiocorner.net/

What is D-STAR*?
D-STAR* (Digital Smart Technology for Amateur Radio) is an exciting new form of Amateur Radio that compliments other parts of the hobby including VHF, HF operation, Contesting and Satellite communications etc. Utilising digital communication and the Internet, D-STAR allows you to communicate worldwide with other operators who are connected to D-STAR* repeaters.
http://www.d-staruk.co.uk/categoryRender.asp?categoryID=3685
An Overview
D-STAR* (Digital Smart Technology for Amateur Radio), a standard published in 2001, is the result of years of research funded by the Japanese government and administered by the JARL to investigate digital technologies for amateur radio. D-STAR* is an open protocol - published by JARL, it is available to be implemented by anyone. Whilst Icom is the only company to date that manufactures D-STAR* compatible radios, any equipment or software that supports the D-STAR* protocol will work with a D-STAR* system.

In a D-STAR* system, the air link portion of the protocol applies to signals travelling directly between radios or between radios via a repeater. D-STAR* radios can talk directly to each other without any intermediate equipment or through a repeater using D-STAR* voice or data transceivers.

D-Star Repeater Sites
Currently there are 17 repeater sites running in the UK, 2 of which are run by Icom UK.

GB7IC has 2 repeaters, a controller and gateway. The 2 repeaters are on 1.2GHz and 430 MHz. The gateway is a PC configured to connect to other D-STAR* repeaters around the world.

GB7DS is a test repeater at Icom UK's offices which has a 1.2GHz data port, a 1.2GHz digital voice port and is connected via a gateway to the internet.

Both repeater sites are fully operational, the activity on these and other D-STAR* repeaters can be viewed at dstarusers.org.

If you want to see details of repeater sites around the world please click here www.dstarusers.org To see where various sites are located around the world, please click the link www.jfindu.net