4DTV

4DTV is the name of the digital TVRO communications satellite receiver box manufactured by Motorola. In big dish satellite viewing circles, 4DTV is essentially synonymous with signals that use the DigiCipher 2 standard of signal encryption and compression, which is also owned by Motorola.

Since 4DTV technology was originally developed by General Instruments (now the broadband division of Motorola) in 1997, it predates DVB-based digital television compression and therefore is incompatible with the DVB standard. 4DTV was originally intended to be the digital signal compression standard for digital television and audio signals beamed to North America, but cannot truly be considered a de facto standard due to the large amount of available North American DVB satellite signals. Approximately 70% of newer first-generation digital cable networks in North America use the 4DTV/DigiCipher 2 format.

4DTV digital channels use the following format:

G1 100 [where "G1" is the special two-character satellite abbreviation and "100" is the arbitrary three-digit channel number assigned to a specific channel on a particular satellite]

4DTV receivers are also designed to receive any remaining analog TVRO satellite channels and feeds. There are three models available either new or second-hand: the DSR-920, the DSR-922, and the DSR-905 sidecar, which is slaved to an analog satellite receiver and can only receive (by itself) digital 4DTV channels.

External links

• Motorola Broadband Division website (http://broadband.motorola.com/)
• Motorola's 4DTV home page (http://www.4dtv.com/)
• Good technical page on digital satellite signals (http://www.coolstf.com/mpeg/)