Browse Definitions:
Definition

8-VSB (8-level vestigial sideband)

8-VSB (8-level vestigial sideband ) is a standard radio frequency ( RF ) modulation format chosen by the Advanced Television Systems Committee ( ATSC ) for the transmission of digital television ( DTV ) to consumers in the United States and other adopting countries. In the US, the standard is specified by the Federal Communications Commission (FCC) for all digital television broadcasting. Countries in Europe and elsewhere have adopted an alternative format called Coded Orthogonal Frequency Division Multiplexing ( COFDM ).

The main ATSC standards for DTV are 8-VSB, which is used in the transmission of video data, MPEG-2 for video signal compression, and Dolby Digital for audio coding.

The 8-VSB mode includes eight amplitude levels that support up to 19.28 Mbps of data in a single 6 Mhz channel . There is also a 16-VSB mode that has 16 amplitude levels and supports up to 38.57 Mbps of data on a 6 Mhz channel. 8-VSB is considered effective for the simultaneous transmission of more than one DTV program (multicasting) and the transmission of data along with a television program (datacasting) because it supports large data payloads.

The ATSC adopted the VSB transmission system because of its large bandwidth , which is needed to transmit HDTV (high definition television) programming. Detractors claim that this larger bandwidth is irrelevant if customers cannot view the transmitted program because of multipath effects. When a signal is transmitted, it is met with obstructions such as canyons, buildings, and even people, which scatter the signal, causing it to take two or more paths to reach its final destination, the television set. The late arrival of the scattered portions of the signal causes ghost images. For this reason, some consumers in metropolitan areas or areas with rugged terrain opt for cable television instead of fighting their antennas for better reception. Because a VSB signal is transmitted on one carrier, it scatters like water blasted on a wall when met with obstacles, which is not a problem with COFDM, the European standard modulation technique, because it transmits a signal on multiple carriers.

VSB advocates state that simply buying an outdoor antenna that rotates solves the multipath interference problem, but critics worry that customers do not want to buy an expensive rotating outdoor antenna to view free television programs. They also worry that the poor reception and the added expense of an outdoor antenna are slowing the transition to DTV in ATSC-compliant countries. The VSB scheme also does not support mobile television viewing. VSB equipment manufacturers are working on solutions to these two problems.

This was last updated in March 2011

Continue Reading About 8-VSB (8-level vestigial sideband)

Join the conversation

1 comment

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

I found this article out-dated and inaccurate. 8-VSB supports 38.57 Mbps, however half of that is used for forward error correction, only 19.28 Mbps is technically usable. When ATSC first began to broadcast, they were all very low power, most of the reception issues were caused by noise due to the signal being very weak. Outdoor antennas were required for faithful reception. Today, with Digital Broadcast being full power, most people have less issues with reception of DTV than they did with the old analog system. An old pair of "rabbit ears" even an old UHF Bow Tie suffice quite well in most urban areas. Multipathing is an issue with frequency more than modulation. Later tests have shown advantages of 8-VSB over COFDM, also remember half of the of data sent is for error correction too. This means nearly 50% of the signal can be obliterated and one would still have a glitch free picture and sound. Even still, Multipathing is less of an issue with 8-VSB than with the old analog system too. In the old NTSC system, multipathing causes the picture to smear, it often took a good outdoor antenna on a rotor to clean the picture up. This isn't the case with 8-VSB. Also multipathing is often a lot weaker than the direct path. What causes light smearing in analog simply ignored as noise, as long as it is below a threshold; then couple that with the forward error correction. Often you can fix your outdoor antenna somewhere between towers within 40 degrees of each tower. You will get a faithful glitch free reception. You can even use omni-directional antennae, something not heard of with NTSC. Contrary, to this article DTV has caused a drop in cable subscriptions. Why pay for less channels with basic analog cable service when you can get more channels in free digital quality?
Cancel

-ADS BY GOOGLE

File Extensions and File Formats

SearchCompliance

  • smart contract

    A smart contract, also known as a cryptocontract, is a computer program that directly controls the transfer of digital currencies...

  • risk map (risk heat map)

    A risk map, also known as a risk heat map, is a data visualization tool for communicating specific risks an organization faces. A...

  • internal audit (IA)

    An internal audit (IA) is an organizational initiative to monitor and analyze its own business operations in order to determine ...

SearchSecurity

  • evil maid attack

    An evil maid attack is a security exploit that targets a computing device that has been shut down and left unattended.  An evil ...

  • Common Body of Knowledge (CBK)

    In security, Common Body of Knowledge (CBK) is a comprehensive framework of all the relevant subjects a security professional ...

  • rootkit

    A rootkit is a program or, more often, a collection of software tools that gives a threat actor remote access to and control over...

SearchHealthIT

  • value-based healthcare

    Value-based healthcare, also known as value-based care, is a payment model that rewards healthcare providers for providing ...

  • health informatics

    Health informatics is the practice of acquiring, studying and managing health data and applying medical concepts in conjunction ...

  • clinical trial

    A clinical trial, also known as a clinical research study, is a protocol to evaluate the effects and efficacy of experimental ...

SearchDisasterRecovery

  • crisis communication

    Crisis communication is a method of corresponding with people and organizations during a disruptive event to provide them with ...

  • Zerto

    Zerto is a storage software vendor that specializes in enterprise-class business continuity and disaster recovery in virtual and ...

  • crisis management plan (CMP)

    A crisis management plan (CMP) is a document that outlines the processes an organization will use to respond to a critical ...

SearchStorage

  • hard disk

    A hard disk is part of a unit -- often called a disk drive, hard drive or hard disk drive -- that stores and provides relatively ...

  • cache memory

    Cache memory, also called CPU memory, is high-speed static random access memory (SRAM) that a computer microprocessor can access ...

  • RAID 10 (RAID 1+0)

    RAID 10, also known as RAID 1+0, is a RAID configuration that combines disk mirroring and disk striping to protect data.

SearchSolidStateStorage

  • hybrid hard disk drive (HDD)

    A hybrid hard disk drive is an electromechanical spinning hard disk that contains some amount of NAND Flash memory.

Close