4DTV

From Wikipedia, the free encyclopedia
Jump to: navigation, search
4dtv-logo.png

4DTV is the name of a Television receive-only (TVRO) consumer satellite television tuner technology manufactured by Motorola for use with large-diameter parabolic satellite dish antennas on the C and Ku frequency bands on multiple satellites. It can tune both analog NTSC/VideoCipher 2 and digital DCII satellite signals.

History[edit]

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 transmissions. Motorola abandoned 4dtv technology when they shut down the mapping stream on 12/31/2010 and converted most of the receivers in use to read one satellite only. There is an outfit that remaps receivers now based in Illinois so the receivers can be used to move the satellite dish again.

Usage[edit]

In 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.

Receiver/Decoders[edit]

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.

Four models are available, either new or refurbished:

  • DSR-920 (discontinued as of 2003)
  • DSR-921 (discontinued as of 2003)
  • DSR-922 (made available in Fall 2000, discontinued)[1][2][3]
  • 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.

High definition access[edit]

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.

Programming providers[edit]

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.

Advantages[edit]

The 4DTV 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.

Disadvantages[edit]

The master feeds for the many channels available can be scattered amongst multiple satellites. The actuator must slowly rotate the large dish into the desired satellite's signal path, and then a further short delay for signal acquisition and lock. This procedure makes rapid "channel surfing" impossible outside the HITS provided channels.

References[edit]

  1. ^ "DSR922 4DTV now available [sic]". Google Groups - rec.video.satellite.tvro. Retrieved 2009-08-28. 
  2. ^ "2000 Satellite News". BUD & 4DTV Info (bigdish.info). Retrieved 2009-08-28. 
  3. ^ "DSR 922 Operator's Guide". General Instrument: Publication #468478-001, Rev B (General Instrument Corp.). 2000.