05 settembre 2007

Firedrake, anatomia di un jammer

Avvincente come una spystory il racconto di come SatDirectory ha individuato l'origine del "Drago di fuoco" (Firedrake), nome convenzionale delle trasmissioni di radiodisturbo (jamming) che i cinesi irradiano per impedire l'ascolto di Sound of Hope, voce ufficiosa el movimento Falun Gong. SatDirectory e il confratello Mediaexplorer, sono due siti Web australiani creati da un gruppo che sorveglia le comunicazioni radiotelevisive satellitari nell'area dell'Asia Pacifico. Le due testate telematiche commercializzano straordinari cataloghi e rassegne multimediali su DVD basati su questa attività di sorvegliamento dei transponder, con materiale video esclusivo Vale davvero la pena visitare la loro libreria online o cliccare qui per ordinare il DVD di Mediaexplorer.
Tornando a Firedrake, oggi mi sono letto d'un fiato il contributo che l'ultimo numero di DXLD di Glenn Hauser pubblica da Mark Fahey di SatDirectory. Come dicevo all'inizio Sound of Hope è l'organizzazione mediatica del movimento dissidente cinese Falun Gong. Da diverso tempo l'emittente, che è disponibile anche via Internet, utilizza facilities taiwanesi per trasmettere verso la Cina, sulle onde corte, notizie e propaganda fortemente contraria al Partito comunista cinese e all'ordine costituito. Evidentemente certe verità sono scomode e il governo reagisce come hanno sempre fatto i governi autoritari dall'invenzione della radio in poi: cercano di impedirne la ricezione. Nei lunghi anni della guerra fredda i sovietici utilizzavano potenti trasmettitori e generatori di rumore nelle frequenze audio. La Cina preferisce un approccio più soft e sommerge le trasmissioni di Sound of Hope con una musichetta tradizionale senza neanche un accenno di annuncio parlato. La potenza usata dev'essere notevole perché il Drago di fuoco arriva dappertutto grazie alla propagazione. Ascoltarlo sulle onde corte è facile: basta andare sulle frequenze della schedule di Sound of Hope. Ma gli australiani hanno capito che il feed della musichetta doveva viaggiare via satellite, perché diffonderlo in altro modo sarebbe stato troppo complicato (e anche perché China National Radio ha riorganizzato completamente - con una bella prova di forza e efficienza - la modalità di distribuzione satellitare dei suoi innumerevoli programmi proprio perché Falun Gong in passato era riuscita a sovrapporsi ai vecchi feed, facendo in modo che i cinesi ricevessero i loro comunicati sovversivi sulle frequenze ufficiali cinesi). Dopo un paziente monitoraggio, ecco spuntare l'audio di Firedrake trasmesso dalla nuova rete di feeder: occupa il canale stereo destro di uno dei pochi canali radio monofonici distribuiti oggi dal satellite Chinasat 6B. SatDirectory promette di inviare su richiesta un CD con l'intera registrazione dei 60 minuti del "programma" di Firedrake.
Le attività di trasmissione e disturbo di SoH sono seguite con apprensione dall'intera comunità dei radioamatori perché molte delle frequenze utilizzate dalla stazione - e quindi interferite dal jammer musicale - ricadono nelle porzioni di banda condivise o assegnate in esclusiva al servizio HAM Radio, con pessime conseguenze sulla possibilità di stabilire dei contatti radio fruttuosi. L'organizzazione sovranazionale IARU, che riunisce le associazioni radioamatoriali nei diversi Paesi, ha pubblicato un interessante documento sulla partita a rimpiattino giocata con i responsabili di Sound of Hope.

Firedrake - The source of China's Radio Jammer found on Chinasat 6B

Some countries fear a free flow of information through the media and often go to extraordinary lengths to ensure they maintain control over the distribution of news and information in their nation. While some governments are kept busy building media firewalls or other barriers to stop outside information being received by their citizens, other groups are just as determined to allow their views to be heard behind these barriers. Information can be diluted or restricted by many different methods. Some information is controlled via a relatively "light" non-technical approach, other "heavy" techniques use various technologies to jam or completely stop the flow of the information considered subversive.
An example of a 'light" approach to control a media outlet may be the ridiculing of Al-Jazeera by senior members of the USA government. The anti Al-Jazeera campaign in the USA has led many in that nation to consider the broadcaster as an evil mouthpiece for Islamic terrorists and not ideal viewing by patriotic Americans. Meanwhile outside of the USA some view the station as un-biased and a shining example of a balanced media organisation. A "heavier" approach may include national restrictions and censorship of the Internet and jamming of radio and television transmissions that do not align to a particular belief. Two groups that definitely don't see eye-to-eye when it comes to beliefs is the government of the Peoples Republic of China and the followers of Falun Gong. Both parties have been accused of being players in a constant war to control the delivery of information, and interestingly part of the war is being played out over satellites.

Falun Gong - Satellite Hackers?

2007 is seeing a massive reorganisation of the domestic radio and television services delivered by satellite links in China. Over recent years the Chinese have been exposed to an embarrassing series of hijacks of these satellite links. The hijacks have seen the official evening news from Beijing being replaced by Falun Gong programming. For many years the AsiaSat, Sinosat and Apstar platforms have been used to distribute media across mainland China. As a result of the hijackings the services are now shifting on mass to two new satellites, Chinasat 6B and Sinosat 3. The new satellites have been built with systems that are designed to prevent the hacking of the services. Chinasat 6B also plays another important role in the war of control of the Falun Gong, it is the source delivering the dreaded Firedrake Jammer to Chinese Radio Jamming transmitter sites.

Firedrake Jammer

The Falun Gong's shortwave radio station The Sound of Hope is the main method of reaching their supporters in mainland China. Sound of Hope programs allege persecution and torture by the Peoples Republic of China, and as you might expect, the Chinese go to incredible efforts to ensure the station is basically impossible to listen to by jamming the station. The Chinese Firedrake Jammer is a powerful transmitter that sits on top of the same frequency as the Sound of Hope. Firedrake covers the Falun Gong programming with loud Chinese Classical Music featuring gongs, flutes and drums. The Firedrake music is so intense that it usually completely dominates the frequency with the Falun Gong program underneath it becoming unintelligible. Shortwave Radio Enthusiasts and Ham Radio operators have been watching China's Firedrake with interest. They believe that the primary Firedrake transmitter location is on Hainan Island off the coast of Southern China, however it is believed that there may be other transmitter sites also in use. It has also been noted that the Firedrake audio is a one hour loop with no announcements. This got us thinking at Satdirectory; how does the Firedrake programming get to the transmitter site? Is it delivered by a tape or CD on repeat or is it like most other Chinese radio, delivered by a satellite link to the transmitter?
Well, a search with our 3 meter dish has found Firedrake! The audio is transmitted on Chinasat 6B within the China National Radio (CNR) satellite feed circuits. Many of the China National Radio feeds are in stereo, however one channel that is solely mono is the CNR 8 - The Voice of the Minorities broadcast which features programs in the Kazakh, Korean, Mongolian, Tibetan and Uighur languages. The CNR 8 audio feed to the Chinese transmitter sites can be found on the left audio channel of a feed circuit labelled "Lzh8Rdjy". On the right audio channel of this feed is the feed for the Firedrake transmitters. Following our discovery we tuned up a shortwave receiver to 17780 kHz which at the time also had the jammer running. The audio from the satellite feed and the shortwave radio were synchronised with no delay. This confirmed that the Firedrake shortwave transmitter site was also being fed by the same satellite feed, otherwise we would have expected a delay of a second or so due to the satellite uplink and downlink path delay when compared to the shortwave broadcast.
Satdirectory can confirm that the Firedrake audio program in exactly 60 minutes (down to the second actually) and we have made a full studio quality copy of the broadcast which can be made available on CD for study and academic use on request.

................................................................

Tuning & Resources

China National Radio and the Firedrake audio feeds are available via Chinasat 6B.
Firedrake - Right Audio Lzh8Rdjy Circuit
Satellite : Chinasat 6B
Orbit Location : 115.5 East
Frequency : 4175
Polarity : Vertical
Symbol Rate : 5990
FEC: 1/2


1 commento:

jammer ha detto...

è guerra, anche se non sembra...