How Iran Silences Unwanted News

April 1, 2010 — -- Hot Bird 8 may be Europe's largest and most powerful television satellite, but it still has little chance when the Iranian regime decides to block its signals. When that happens, the Farsi services of the BBC and Voice of America instantly disappear from television screens -- and not just in Iran, but also throughout the satellite's entire coverage area.

Tehran has targeted the satellite in an effort to prevent critical foreign media coverage from reaching domestic viewers. Even though the United Nations has condemned it as an act of sabotage, the international community can do little to stop it.

The Arabic service of the German public broadcaster Deutsche Welle was also affected by the attacks on Hot Bird 8. "We experienced disruptions in December and February," Deutsche Welle spokesman Johannes Hoffmann told SPIEGEL ONLINE. "A total of over 30 hours of programming was affected."

Hoffmann believes the attacks were a "targeted act to block news coverage" on Iran. For example, he noted , there were problems in February during celebrations marking the anniversary of the Iranian revolution.

France-based satellite provider Eutelsat, which operates Hot Bird 8, also believes the jamming attempts are deliberate. "This is not happening by accident," says Eutelsat spokeswoman Vanessa O'Connor. The latest attempt to block the satellite occurred on March 20, according to the BBC and Voice of America.

Indeed, it would seem that it is often surprisingly easy for the regime in Tehran to suppress information from abroad. Although Hot Bird 8 is in geostationary orbit about 36,000 kilometers (22,400 miles) above the Earth, it can be easy to sabotage, something which is also true for many other satellites. The Iranians only need to transmit a strong signal in the satellite's direction using the same frequency with which programs are transmitted from the original ground transmission station.

In the case of Deutsche Welle, the so-called uplink is sent from a ground station in Usingen, in the German state of Hesse. "The satellite cannot, however, determine whether the signal is coming from Usingen or from Tehran," says Deutsche Welle chief engineer Horst Scholz. If in doubt, he explains, the satellite chooses the stronger signal, which allows it to be deceived by the interference coming from Iran.