Inmarsat Standard C
Short history of Inmarsat standard C @ICRC
"The C standard introduced in 1990 uses a small size omnidirectional antenna that allows you to use a terminal everywhere. All this material is stored in an easily transportable suitcase. On the other hand, this standard does not allow speech and the flow of data and messages is weak.
"The C standard introduced in 1990 uses a small size omnidirectional antenna that allows you to use a terminal everywhere. All this material is stored in an easily transportable suitcase. On the other hand, this standard does not allow speech and the flow of data and messages is weak.
- October 1990 - start of tests in Geneva of a standard satellite station C updated available by our supplier.
- January 14, 1991 - departure for Bahrain with radio equipment and a standard C suitcase (stand-by to go to Kuwait)
- January 18, 1991 - verbal authorization to use the satellite station
- March 03, 1991 - departure from Bahrain via Doha and Shiraz for Teheran in order to retrieve a suitcase standard satellite C to go to Baghdad.
- March 04, 1991 - departure from Teheran by car for the Iran / Iraq border
- March 05, 1991 - several hours at the border awaiting official authorization to enter in Iraq with a satellite suitcase.
- March 06, 1991 - standard C provisional installation at the ICRC delegation in Baghdad and dispatch of the first message.
Philippe Monnard - HB9ARF
"Arrived in Croatia in 1993, the administrator informed me of an annual invoice of 1.9 Million Swiss Francs for satellite transmissions. “Do something to reduce this bill next year,” he told me.
Not really familiar with the Sat-C system, I looked at the many devices used throughout the former Yugoslavia and their use by non-technicians.
The transmissions were made in “RollsRoyce” mode, in 8 bits per character. French with all its accents was then reduced to 5-bit transmission (the old mode of telex).
The administrator then showed me the page of his user manual which stated that a transmitted page cost 2 US Dollars. I then realized that at the ICRC we had mixed bits and bytes and that each page actually cost us 8 times as much, or 16 Dollars!
In addition, the store and forward (memorizing the message on board the satellite then returning it to land) delayed acknowledgments of receipt and the same message was often transmitted several times, which multiplied the cost of transmission.
We quickly abandoned these satellite transmissions and returned to the much more economical PACTOR."
Not really familiar with the Sat-C system, I looked at the many devices used throughout the former Yugoslavia and their use by non-technicians.
The transmissions were made in “RollsRoyce” mode, in 8 bits per character. French with all its accents was then reduced to 5-bit transmission (the old mode of telex).
The administrator then showed me the page of his user manual which stated that a transmitted page cost 2 US Dollars. I then realized that at the ICRC we had mixed bits and bytes and that each page actually cost us 8 times as much, or 16 Dollars!
In addition, the store and forward (memorizing the message on board the satellite then returning it to land) delayed acknowledgments of receipt and the same message was often transmitted several times, which multiplied the cost of transmission.
We quickly abandoned these satellite transmissions and returned to the much more economical PACTOR."
Peter Kunz - HB9MCL
Inmarsat Standard-C, telex by satellite - technical sheet:
This mode of communication was put into service during the First Golf War in 1991, easy and efficient. For the first time, the ICRC, in a way outsourced its telecommunications, we now depend on a third party. Connected to a car battery, even a delegate was able to use it. Its only drawback is its high transmission price.
- L-band transceiver (1500-1600 MHz) on INMARSAT geostationary satellites with global coverage (4 Satellites)
- Transmission of relayed written texts (store / forward) in 5/7/8 bits per character
- Acknowledgment of receipt of messages
- Omnidirectional antenna on the suitcase
- 12-24Vdc power supply
- "All-in-one" in a blue suitcase with PC and printer and all cabling, but without battery
- Required activation from a service provider and Inmarsat
- No monthly rental amount
- Billing by the number of bits transmitted, not by bytes (1 byte = 8 bits) as we thought at the beginning!
This mode of communication was put into service during the First Golf War in 1991, easy and efficient. For the first time, the ICRC, in a way outsourced its telecommunications, we now depend on a third party. Connected to a car battery, even a delegate was able to use it. Its only drawback is its high transmission price.