The 4DTV system’s main selling point is that it makes use of first-generation digital master feeds on several satellites and hundreds of channels. Therefore, a high quality signal is received, compared to other programming options that are typically compressed and re-uplinked. Being a C-band system the 4DTV has the advantage of signal stability, great satellite footprint and no rainfade. This is a problem with services such as Dish Network and DirecTV satellite providers since they re-uplink on KU and KA bands.
In the United States, National Programming Service, LLC (NPS) was the primary provider of subscription programming to 4DTV and C band/Ku band users. They ceased operations as of December 26, 2010 after making a controversial attempt of converting all of their customers over to Dish Network which failed. The largest providers are now Satellite Receivers, Ltd. (SRL) and Skyvision who sell programming from the Headend In The Sky (HITS) service by Comcast and will continue to do so in 2011 and beyond. The HITS services use the Comcast Subscription Authorization Center (SAC) for the channels being broadcast on the AMC 18 satellite located at 105 degrees West (W5 or X4 tile on 4DTV). In Canada, Dr. Sat is now the primary provider for HITS subscription services offered on C-Band after Satellite Communications Source ceased operations.
The HDD200 decoder interfaces with the 4DTV receiver via the Multi-Media Access Port (MMAP), allowing access to several high definition channels available on the 4DTV system. This unit is no longer in production.
4DTV receivers were designed to receive analog NTSC (except the DSR-905) in the clear or VideoCipherII channels and feeds, as well as digital Digicipher 2 signals as a TVRO satellite system on both C and Ku bands.
Three models are available, either new or refurbished:
DSR-920 (discontinued as of 2003)
DSR-922 (made available in Fall 2000, discontinued)
DSR-905 A.K.A. sidecar, was designed to work in tandem with a dish mover or slaved to an analog satellite receiver as a dish mover. It can only receive digital 4DTV DCII channels.
The high cost of these receivers, typically in the US$300-US$700 range, and their partial obsolescence in regards to receiving the latest DCII HD signals may be a factor that has contributed to rapidly falling subscriber numbers of the 4DTV system
4DTV digital channels use a “An nnn” format, where “An” is the special two-character satellite abbreviation and “nnn” is an arbitrary three-digit channel number assigned to a specific channel on a particular satellite. For example, G1 100 would refer to the old Galaxy 1 satellite position and “100″ as the three-digital virtual channel on that satellite.
n big dish satellite television viewing circles, 4DTV is essentially synonymous with signals that use the DigiCipher 2 standard of signal encryption and compression, also owned by Motorola, although the receivers are also capable of handling analog channels.
DigiCipher 2 was originally intended to be the digital signal compression standard for digital television and audio signals beamed to North America, but cannot be considered a de facto standard, due to the large number of DVB satellite signals available in North America.
About 70% of newer first-generation digital cable networks in North America use the 4DTV/DigiCipher 2 format.
4DTV technology was originally developed in 1997 by General Instrument, now the broadband division of Motorola. The 4DTV format is contemporary to the DVB-based digital television broadcast standard but its completion came before that of DVB and thus it is similar but incompatible with the DVB standard. The DigiCipher 2 encryption system is used in digital channels much like the VideoCipher and VideoCipher II systems were used for analog encrypted transmissio coming 4/20/13