The Concentrator Unit consists of four main sub-systems, Line Modules, Digital Concentrator Switch, Digital Line Termination ( DLT ) units and Control.

Up to 32 line modules are connected to a Digital Concentrator Switch unit using 2 Mbit / s highways giving each Concentrator Unit a capacity of up to 2048 subscriber lines.

Concentrator Units can either stand alone as remote concentrators or be co-located with the Digital Local Switching Unit.

Starting with two Digital Tandem Switch ( DTS ) voice-switching systems designed specifically for them by the Collins Radio Company of Cedar Rapids, Iowa ( later a division of Rockwell International ), MCI began offering competitive circuit-switched direct-dial services using a combination of their own microwave circuits and leased circuits from AT & T made available to them from the landmark Carterfone decision.

The Digital Multiplexed Switch was selected as the basic switching design for the project.

She directed the 1993 Digital Pictures FMV video game Double Switch.

The station is also available on MXR regional DAB multiplexes in the North West, North East, the Severn Estuary and Yorkshire, as well as on Switch Digital in central Scotland, having replaced Heart Digital.

The heart of the DLE is the Digital Switching Subsystem ( DSS ) which consists of Time Switches and a Space Switch.

It was also broadcast as a DAB station via the Switch Digital consortium in 2000 and ran on FM via a Restricted Service License in October 2001.

The DMS-100 Switch is a line of Digital Multiplex System ( DMS ) telephone exchange switches manufactured by Nortel Networks.

The format of the game was similar to that of the Digital Pictures full motion video games such as Night Trap and Double Switch, with two important differences.

Once the Digital Switch Over ( DSO ) occurs the plan is that most transmitters will revert to their original groups, source Ofcom July 2007.

Like other community radio stations that are located in the Brisbane licence area, Switch 1197 broadcasts on DAB + Digital Radio, with the majority of its programming being that of a simulcast of its main terrestrial programming output.

On the 3rd December 2010, Wrotham began transmitting DAB: CE London ( London 1 ), Switch London ( London 2 ), DRG London ( London 3 ), Digital One and the BBC National DAB multiplex.

Switch London is a DAB ensemble operated by Switch Digital ; it broadcasts from a variety of sites in and around London ( Alexandra Palace, Arkley, Bluebell Hill, BT Tower, Colindale House, Crystal Palace, Guildford, Hampstead, Harrow Weald, Hemel Hempstead, Leatherhead Stoke d ' Abernon, Mount Vernon, Otford, Reigate, Richmond Hill, Shepherds Bush, Shooters Hill, Sidcup, Staines, Uxbridge and Zouches Farm ).

Following the administration in 2002, the three multiplexes that were run by ITV Digital remained blank until a week or so before Freeview's launch.

Freeview officially launched on 30 October 2002 at 5 am when the BBC and Crown Castle ( now Arqiva ) officially took over the digital terrestrial television ( DTT ) licences to broadcast on the three multiplexes from the defunct ITV Digital ( originally called ONdigital ).

Following the collapse of ITV Digital, the Independent Television Commission re-advertised the licences for the three multiplexes ( MUX B, C and D ) that had been used by ITV Digital.

A contract to run a nationwide system, with six multiplexes from main sites, and four from relay sites was awarded in 2001 to ITS Digital Limited, led by former RTÉ executive, Mr Peter Branagan and trading as " It's TV ", who intended to launch a pay TV and broadband service.

The transmitter broadcasts six digital television multiplexes, as well as VHF or FM transmitters for the four BBC national stations, independent national station Classic FM, four local commercial radio stations ( BRMB, 100. 7 Heart FM, Kerrang 105. 2 and Smooth Radio ), the BBC's local service WM and DAB ( Digital Audio Broadcasting – i. e. Digital Radio ).

The Belmont transmitter has the Digital One and MXR Yorkshire 12A multiplexes but does not transmit Lincs FM on DAB.

It transmits high power Digital Audio Broadcasting ( DAB ) signals for Digital One and BBC National DAB multiplexes, as well as a lower power local service to Glastonbury for MXR Severn Estuary.

The space ITV Digital had rented on other multiplexes initially became empty again, but some were rented out to allow new channels to launch.

Since the digital switchover in April 2012 no television has been broadcast from Croydon, but is still used as a backup for Crystal Palace for the BBC A & B and Digital 3 & 4 multiplexes.

Digital television was officially launched on December 15, 2006 when the operator Eesti Digitaaltelevisiooni AS launched its pay service ZUUMtv, operated by Starman, on two multiplexes.

The London variation is also broadcast on numerous Digital Radio multiplexes across the country, allowing Xfm to reach near-national coverage.

Digital cable operators and internet providers also provide radio signals.

* Digital signal processing, the study of signals in a digital representation and the processing methods of these signals

86 % of exchanges now digital ; existing copper subscriber systems now being improved with Asymmetric Digital Subscriber Line ( ADSL ) equipment to accommodate Internet and other digital signals ; trunk systems include fibre-optic cable and microwave radio relay

Digital television ( DTV ) is the transmission of audio and video by digitally processed and multiplexed signal, in contrast to the totally analog and channel separated signals used by analog TV.

Other standards, such as Digital multimedia broadcasting ( DMB ) and DVB-H, have been devised to allow handheld devices such as mobile phones to receive TV signals.

Some signals carry encryption and specify use conditions ( such as " may not be recorded " or " may not be viewed on displays larger than 1 m in diagonal measure ") backed up with the force of law under the WIPO Copyright Treaty and national legislation implementing it, such as the U. S. Digital Millennium Copyright Act.

Digital television signals must not interfere with each other, and they must also coexist with analog television until it is phased out.

Digital or discrete signals behave as binary switches, yielding simply an On or Off signal ( 1 or 0, True or False, respectively ).

Digital signal processing is the processing of digitised discrete time sampled signals.

Larger DS3 signals can also have their DS0 signals switched in Digital Network Unit SONET ( DNUS ) units, without demultiplexing them into DS1.

Digital electronics, or digital ( electronic ) circuits, represent signals by discrete bands of analog levels, rather than by a continuous range.

Employees at Bellcore ( now Telcordia Technologies ) developed Asymmetric Digital Subscriber Line ( ADSL ) and filed a patent in 1988, by placing wide-band digital signals above the existing baseband analog voice signal carried between telephone company telephone exchanges and customers on conventional twisted pair cabling facilities.

* Digital Pattern Generator, for generating digital ( logic ) type of signals

Digital signals can also be sampled instead of continuously monitored.

* Digital signal processing, the study and implementation of signals in digital computing and their processing methods

Reception of free-to-air satellite signals, generally K < sub > u </ sub > band Digital Video Broadcasting, for home viewing is still common in Europe, India and Australia, although the TVRO nomenclature was never used there.

Digital recording equipment uses the connection for synchronization of various components via the transmission of word clock timing signals.

It converts any audio signals on a PC or game console into a 5. 1-channel 16-bit / 48 kHz Dolby Digital format at 640 kbit / s and transports it via a single S / PDIF cable.

Digital video signals are converted to analog in televisions and cell phones to display colors and shades.

Like all video switchers that use a frame buffer to create DVEs ( Digital Video Effects ), the video path through the Toaster hardware introduced delays in the signals when the signal was in ' digital ' mode.

* Converting S-Video to or from digital video signals, depending on the digital standard involved, requires more processing-such as the CS4954 NTSC / PAL Digital Video Encoder when converting from 27 MHz 8-bit YUV, 8-bit YCbCr, or ITU R. BT656.

* Physical interfaces for transmission of television signals and related data ( such as SMPTE time code and the Serial Digital Interface ) ( SDI )

Digital audio uses pulse-code modulation and digital signals for sound reproduction.