ATSC (Advanced Television Systems Committee) - was established in 1982 as an international, non-profit organization developing standards for advanced television systems. In particular, ATSC is working on coordinating television standards between various communication media in the digital TV environment, interactive systems and multimedia broadband communications. ATSC standards focus on the transport layer, i.e. audio, video and data transmission. The organization also develops and presents strategies for introducing digital television. The name ATSC is also defined by the standard of digital terrestrial television developed by this organization, in force among others in the USA. It is the equivalent of the European standard DVB-T.
About DVB-T
DVB-T and ATSC standards are not compatible with each other - ATSC decoders are not able to receive the signal broadcast in the DVB-T standard and vice versa. The Commission sets specific standards for displaying the image in resolution: SDTV, EDTV and HDTV. Image refresh parameters: depending on the resolution, image refresh takes the following values: SDTV - 24 frames / s (48 images / sec) or HDTV - 30 frames / sec (60 images / sec). Within the standard the following image formats are supported: SDTV 480i60, 480p30 (NTSC), EDTV 480p60, HDTV 720i60 720p24, 720p30, 720p60, 1080p24, 1080p30 and 1080i60.
A television standard determines how different information, such as video and audio data, is transmitted from the transmitter to the receiver to build a harmonic aggregate during transmission. It makes sense to distinguish between three different levels of transmission:
Definition of the picture and sound parameters;
Electrical signal transmission in the baseband: either as analog video and audio or digitally coded;
Remote transmission: Analog or digital RF modulation types.
Today in fact all the modern TV Broadcast systems are digital or at least partial digital and the most common are:
PAL plus: an extension of PAL, backwards compatible
D2-MAC: brought a quality improvement mainly by separate (time-multiplexed) transmission of the image signal, the color signal and the digital audio signal, was mainly transmitted via satellite, and could not prevail.
HDTV: collective term for television standards with higher resolutions
DVB: Digital Video Broadcasting, collective term for various digital television standards
The digital television standards are based on some characteristics of the analog television standards, such as line number and frame rate. To compress the data, the MPEG-2 standard is usually used in North America; however the rest of the world uses H264 as better compression standard which uses less data. While the vast majority of Television sets in the USA are MPEG2, some companies have recently been manufacturing new models with H264 capability due to the surge in IPTV.
Unlike analogue television standards, another feature of digital television standards is the number of columns of an image. Together with the number of picture lines you get the so-called picture resolution in picture elements (pixels). The number of columns is ideally chosen so that the height of the individual pixels does not differ significantly from their width in the image display. Instead of the traditional aspect ratio of 4: 3 is due to the changed display devices (flat screen TV and video projectors) amplified 16: 9 used.
In order to fully and completely use all the possibilities and advantages of the television signal coding systems existed, it is worth equipping yourself with the appropriate facilities that harmonic supports all of these systems. Among the few companies offering a wide range of this type of equipment, Thor Broadcast deserves attention. Here are the top five of their most popular devices:
This Device is a Combination Encoder Modulator for converting 1 to 4 channels of full HD video in broadcast freindly SDI format to real time ATSC 8VSB modulated television channels.
Features
Broadcast up to 4 HDSDI sources as North American ATSC Antenna & IPTV Channels.
Input any SDI source up to 3G-SDI @1080p60
ASI Input SPTS or MPTS up to 120 Mbps
Fully Network Managed through browser NMS gui
ATSC 19Mbps 8VSB RF Output 4x carriers
IPTV Output Unicast or Multicast IGMP UDP, RTP, RTSP
ASI Output with multiplexer cherry picking
Integrates fully independent encoders with a multiplexer and modulator
Modulates up to 4 adjacent 8VSB carriers compatible with ATSC format
Supports full HD 1080p60 input & encoding from any HD-SDI digital video source
Each encoder independently configured: supports all standard HDTV resolutions
IPTV output on second network port in UDP, RTP,RTSP IGMP Multicast or Unicast format
DVB-ASI output on mirrored BNC terminals for use in broadcasting systems
Fully network managed device with all settings configurable through web browser
Low Latency available 300/500/800ms delay via different modes - IP will always be closer to 800ms due to the decoding (these values are end to end, not just the encoding speed)
Support CC (Closed Caption) EIA608 (from CVBS input)
1-4 CATV RF Output up to 4 Adjacent channels
QAM-256/64, DVB-T & ATSC formats available
Fully IP Control and Network Management through browser
Front Panel LCD local control
IPTV Output Unicast or Multicast IGMP UDP, RTP / RTSP
ASI Output multiplexer with cherry picking
Low Latency available 300/500/800ms delay via different modes - IP will always be closer to 800ms due to the decoding (these values are end to end, not just the encoding speed)
Dolby AC3 or MPEG1/2 Audio Encoding
MPEG2 or MPEG4 H.264 Video Encoding
Firmware for ATSC, DVB-T, DVB-S2 Available
VCT (Virtual Channel Table) support for DVB-C and ATSC
This Device has 12 Indpepndent SDI to CATV RF Video inputs.This unit is a Coax Modulator and IP Video Encoder. It Provides IPTV MPEG2 and H.264 Encoding. With this Device you can provide SDI Video distribution over COAX and IP
Features
12 HD-SDI inputs with MPEG2 & MPEG4 AVC/H.264 Encoding
1 RF tuner input for re-mux The tuner - base model support ATSC but QAM or DVB-T or ISDB-T tuner could be requested
256 IP(DATA1 port only) input over UDP and RTP protocol
MPEG1 Layer II, MPEG2-AAC, MPEG4-AAC, Dolby Digital AC3 (2.0) encoding AC3 (2.0/5.1) passthrough
16 groups multiplexing /Scrambling/ DVB-C QAM or ATSC modulating
8 groups multiplexing / DVB-T modulating---Optional
16 MPTS IP (DATA2 port only) output over UDP, RTP/RTSP
8 MPTS IP (DATA2 port only) output over UDP, RTP/RTSP--only for DVB-T RF out
PID remapping/ accurate PCR adjusting/PSI/SI editing and inserting
Thor Universal multi-channel SDI and HDMI Modulator with QAM, ATSC, DVB-T, or ISDB-T coax RF output
Features
8 Independent HDMI and SDI Inputs - (individually selectable for each of the 8 channels you can output)
HDMI is HDCP compliant for use with any source
SDI Inputs include support for Closed Caption 708
Outputs 8 separate Clear CATV RF channels QAM / ATSC - 8VSB / DVB-T / ISDB-T (selectable in the GUI)
RF output on each of the 8 RF channels can be individually set to a frequency and modulation standard (2 on QAM, 3 on ATSC, 4 on ISDBT, etc)
DVB-C Annex A and B - QAM 64, QAM 256
Supports full HD video up to 1080p/59.94/60, other resolutions included are 1080i, 720p, 480i also supported
Low Latency supported; 2 different latency settings - 500/1000ms
Video encoding rate up to 25Mbps
MPEG2 Video Encoding
Dolby AC3 and MPEG1 Layer 2, & AAC audio encoding
VCT - Virtual channel number and Name supported
Frequency - 50Mhz to 900Mhz
NMS web interface controllable
Easy to use web Gui Interface (setup and status)
LED's Status on front panel shows HDMI in blue or SDI in green for easy to see video detect link
LCD Display and front panel control buttons for setup, control and status
Powerful processing with the best MPEG2 video encoding chip
First High Density HDMI and SDI input modulator on the market
Lowest cost per channel in perfect HD resolution for any application from Live Sports, House of Worship, Concerts, Theaters, Malls, Airports, Hotels, Military, Private Enterprise
Thor Broadcast offers a wide variety of ATSC (and DVBT) options of professionally designed and utilized modulators, most of which can encode in MPEG2 or H264. In order to create a headend that integrates exactly what you need is a crucial starting point; most of the time electing to go with something that will work with your current infrastructure to blend seamlessly is our overall goal. Having knowledge of old, and new options, Thor will help assist breakdwon comprehensive options for the best fit for you.
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