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German astronaut
Thomas Reiter, DF4TR |
Ariss School Link with Thomas Reiter
EchoLink and IRLP information
On Saturday 29 July 2006 at 12.27 UTC, ARISS will set up a live space
talk for ESA Space Camp in Patras, Greece with German astronaut Thomas
Reiter, DF4TR presently onboard the International Space Station.
There are no daylight passes of the ISS over Europe that day. Consequently,
the radio contact will be performed by ARISS ground station in Honolulu,
Hawaii, operated by Nancy Rocheleau, WH6PN. Signals will be relayed to
Greece by telebridge.
The audio of this QSO will be made available real time and worldwide
to amateur radio operators by means of EchoLink and IRLP.
For those who are not familiar with these “Voice on Internet Protocol”
(VoIP) modes, here is an introduction to both systems.
VoIP modes for Ariss school contacts
When conditions do not allow a direct radio contact between the International
Space Station and the school or other event location, ARISS provides a
so-called “telebridge”.
ARISS counts several dedicated ground stations around the world. When
needed, the radio contact is done by one of these ground stations and
the audio signals are relayed by telephone line to the location where
the event takes place.
With the audio from the ISS and the event location being available on
this telephone line (bridge), ham radio operators from the EchoLink and
IRLP ARISS audio feed teams take the audio from the bridge and feed it
into the IRLP and EchoLink ham radio
systems, to allow ham radio operators around the world to listen to these
contacts live.
EchoLink
The EchoLink system uses VoIP through the Internet to transmit audio
between two or more locations. The in and out of audio at all EchoLink
locations (nodes), can be done by connecting ham radio transceivers or
repeaters to Windows based computers. Alternatively, microphones and speakers
can be used connected to computers to communicate through this system
without ham radio transceivers or repeaters. In any case, before any node
can participate in such transmissions, a verification is made during the
installation of the EchoLink program to ensure that only licensed ham
radio operators can use this system.
The EchoLink system is designed for easy installation on computers with
the Windows operating systems. It only runs on Windows computers.
The installation program for EchoLink is available free of charge for
downloads from www.echolink.org/
with good help file information on the installation and use of this program.
The ARISS EchoLink audio feed team feeds the audio from bridge contacts
into the following two servers, called “Conferences” in EchoLink
speak:
AMSAT (node 101 377)
JK1ZRW (node 277 208)
These two servers allow for many EchoLink nodes to connect to them at
the same time. Please give JK1ZRW your preference during such audio feeds
to keep the load light on the AMSAT server.
During audio feeds, text messaging can be used during ARISS audio feeds,
while all nodes connected to these two servers are being muted (to prevent
inadvertent interfering transmissions). After the completion of ARISS
contacts, all connected nodes will be un-muted to allow for comments and
information exchanges.
IRLP
The IRLP system, for licensed hams only just as the EchoLink system,
also uses VoIP through the Internet for audio transmissions between different
nodes.
The IRLP system can only be used by having ham radio transceivers or
repeaters connected to each node. The IRLP system runs only on computers
using the Linux operating system.
To allow for many nodes to participate in round table conversations,
servers have been set up, called reflectors in IRLP speak. Each reflector
can handle many simultaneous connections.
To connect a node to a reflector, most nodes are set up so that one only
has to key in the number of a reflector, e.g. 9010.
The reflector 9010 has been created to facilitate the distribution of
ARISS bridge contact audio. During such events, simply dial in 9010 using
your microphone touch pad while transmitting on the frequency of the IRLP
node you are using to connect to the Discovery Reflector 9010. To disconnect
the node you are using from the reflector, dial 73 on your node’s
frequency and you should hear a message that you are being disconnected.
Good information on the use of the IRLP system can be found on www.irlp.net
Summary
We hope that you will find the time to listen in on some of the ARISS
telebridge contacts. If you need more information on how to listen and
/ or when such contacts take place, feel free to e-mail Dieter kx4y@amsat.org
with ARISS audio feeds in the message title.
As soon as dates and times for upcoming contacts are known, that information
is being posted on the calendar of events on the AMSAT web site www.amsat.org
If you want to be notified by e-mail of upcoming ARISS bridge contacts
with audio feeds into EchoLink and IRLP, please e-mail a request to Dieter,
KX4Y and he will put you on his distribution list of listeners.
ARISS, Amateur Radio on the International
Space Station, an international working group of several amateur radio
societies from countries participating to the ISS, provides a free educational
outreach programme in collaboration with the Space Agencies, involving
a team of volunteering amateur radio operators.
73
Gaston Bertels, ON4WF
ARISS-Europe chairman
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