Asymmetric Digital Subscriber Line (ADSL) is the technology that brings broadband Internet into our homes over the phone line. Increasingly it is also a way of receiving television and video services, such as Video on Demand (VOD), all over an ordinary telephone line (not currently available on Freeview).

This allows you to divert your TV aerial signal to several rooms. You connect the aerial lead to the input socket and then run extension leads from the output. Because the signal is amplified it can be split without becoming weaker. If you want to split it just two ways, and have a strong signal from your rooftop aerial, you may not need to go to the expense of one of these.

The way our television is transmitted and recorded traditionally before it goes digital. It is called analogue because the electrical signal ‘represents’ the picture and sound signals rather than being coded into a series of ‘1’s and ‘0’s.

Audio description describes what is happening on screen for those who have difficulty seeing. It is an additional narration that fits between dialogue and describes action sequences, body language, facial expression, costume and scenery. No audio description is available in New Zealand at this time.

We are told TV signals are transmitted at certain frequencies, but in fact they spread a little either side of the frequency. The amount of spread is called the bandwidth. With digital, the greater the bandwidth, the more digital data that can be sent. More data can give the broadcaster a choice - like better picture quality or more channels in their allocated bandwidth. Similarly, they can choose to allocate more or less bandwidth to data service and so speed up or expand the EPG and/or teletext services.

A transmission with high bandwidth, so the data is delivered quickly. The term broadband is usually associated with Internet access (eg ADSL or cable) and for this application it usually means faster access.

In typical home applications, a component video signal is typically connected using three RCA cables, normally red, green, and blue. This provides a better quality video image than composite.

Component video is a video signal that has been split into two or more components. In popular use, it refers to a type of analogue video information that is transmitted or stored as three separate signals. Component video can be contrasted with composite video in which all the video information is combined into a single line level signal. Component video cables do not carry audio.

In typical home applications, a composite video signal is typically connected using an RCA jack, normally yellow (often accompanied with red and white for right and left audio channels respectively).

Composite video (also called CVBS - Composite Video Blanking and Sync) is the format of an analogue video signal. It is a composite of three source signals called Y, U and V (together referred to as YUV) with sync pulses. Y represents the brightness or luminance of the picture and includes synchronizing pulses, so that by itself it could be displayed as a monochrome picture. U and V between them carry the colour information.

Cathode Ray Tube. A CRT TV is a conventional ‘TV-tube’ television. Bulky and heavy compared to the latest flat panel TVs, but still capable of producing high quality pictures.

Digital Audio Broadcasting - the DAB service is radio’s equivalent of digital TV. It gives interference-free reception and has room for extra stations. There is no DAB in NZ at this time.

A digital receiver converts the digital signal so that you can see and hear all of Freeview’s channels through your existing television. Eventually all new TVs will have a digital receiver built-in.

Digital switch over (also known as Analogue switch-off ). The point at which the analogue signal will be ‘switched off’ and only a digital signal will be broadcast. This date will be determined by the New Zealand Government, see here for more information.

Digital Television Recorder - sometimes called a Personal Video Recorder (PVR), Personal Digital Recorder (PDR) or Digital Video Recorder (DVR) - is a smart digital receiver that records programmes to a hard drive (like a computer saves information) instead of on a video tape. Programmes you want to record can be selected directly from the on-screen Freeview Guide (EPG).

See MyFreeview|HD_® (FAQ) for more on the features of Freeview approved DTRs.

Digital terrestrial television transmitted through an aerial. In New Zealand DTT will be used by Freeview and is scheduled to be available from April 2008.

Digital Television

Digital Video Broadcasting - a European standard for digital television technology: DVB-C for cable, DVB-S for satellite and DVB-T for terrestrial. All three have been adopted in New Zealand

Digital Versatile Disc - though they may all look the same, DVD discs come in many forms (hence the word versatile). The most popular (usually simply referred to as DVDs) are discs containing pre-recorded films, concerts or music videos. Other formats include DVD +/-R, DVD+/-RW and DVD-RAMs, which can be used at home to record TV programmes or computer files.

Because a DVD recorder only has an analogue tuner built in, you need to use it with an external digital receiver (or digital TV) to record digital TV.

To record from your digital receiver or digital TV you’ll need to ensure it is powered on and on the correct channel for the recording to be successful (note: you will not be able view a different channel while the recording is in progress).

We recommend using a My Freeview_® digital television recorder. MyFreeview|HD_® allows you to pause, record and replay live TV.  You can record an entire series at the touch of a button and record two channels at once.  You can even record in High Definition.

Electronic Programme Guide - the on-screen TV guide, a listing of TV channels and programmes. You can use it to switch to the programme you want, or to select a programme to record (if you are using a PVR). The information is sent by the broadcasters with 7 to 8 days worth of programming. Different brands of digital receiver may display this information in different ways. The Freeview Guide displays both a channel listing view and a now/next on all channels view of the programme listings.

New Zealand’s digital television and radio service that is transmitted via satellite and UHF aerial. No subscription is required.

Free-to-air - a programme or service that you don’t need a subscription to get (there is no encryption). FTA digital TV is available through Freeview’s digital terrestrial and satellite services.

High-bandwidth Digital Content Protection (HDCP) is a form of Digital Rights Management (DRM) developed by Intel Corporation to control digital audio and video content as it travels across High-Definition Multimedia Interface (HDMI). HDCP adds scrambling to the signal which can only be un-scrambled by a compliant display.

For a significant proportion of their schedules NZ broadcasters are not the rights owner, therefore they must do what the rights owner requires them to do. The major international programme suppliers require HDCP or similar on high definition digital outputs for Free-to-air broadcasts. For Freeview|HD _® signals to be displayed in HD quality the television needs an HDCP compliant HDMI input.

High-Definition Multimedia Interface (HDMI) is a new type of connection between digital receivers, DVD players, game machines and TV’s. It is fast becoming standard in most new devices and surpasses similar analogue devices like SCART and component connections in both quality and simplicity. It also has the ability to work with new and developing software protection methods required by programme content owners (e.g. HDCP). An HDMI cable is required in order to get a High Definition picture with Freeview|HD_®.

Nearly all internationally produced movies and most television programmes are now HD. This means they have a higher resolution (either 720 or 1080 vertical lines in the picture) than standard definition (576 lines). 1080i and 720p are the two common broadcast formats; ‘p’ stands for progressive and ‘i’ interlace scanning. The resulting picture quality is therefore considerably better and HD also provides other benefits such as smoother motion, richer and more natural colours and surround sound.

Picture quality may vary depending on hardware and signal strength. Above is an example of the picture you may get with each signal. The SD (analogue) example shows a picture with static interference. A picture delivered by a digital signal is not affected by this.

To be ready for HD broadcasts you’ll need a TV with at least 1280 * 720 resolution and an HDMI (High-Definition Multimedia Interface) input, an HDMI cable, and it must have HDCP (High-bandwidth Digital Content Protection) or no HD picture (most TV’s that meet these requirements say ‘HD Ready’ but check carefully before you buy). Then you’ll need a HD capable digital terrestrial receiver (to decode the digital signal).

In summary there are four requirements to enjoy the HDTV experience:

  * A UHF aerial
  * An HD capable digital terrestrial receiver
  * A high definition capable television (at least 1280 x 720 resolution)
  * An HDCP compliant input and HDMI cable

Integrated Digital Television - a TV with a built-in digital HD receiver so you do not need a separate digital box.

This covers any system where the user can choose extra services or respond to events. For digital TV it usually refers to extensions to the traditional teletext service (this is often call Digital Text). For instance, you could select and watch a particular sporting event from a multi-screen selection, or find out more information about a TV programme, or check the weather forecast with supporting graphics. It can also include what is known as ‘enhanced TV’ applications such as casting a vote, or playing alone with a quiz show.

Internet protocol TV - a TV service delivered over the internet by phone line or cable. These take two forms; 1) A managed service provided by a telecom provider using dedicated bandwidth usually including linear and Video on Demand (VOD) services; or 2) What is often called ‘broadband TV’ (video via the internet). This means you can ‘tune in’ to selected TV or radio stations or programmes from anywhere in the world, but quality may not be as good as managed services due to the fact that the bandwidth is shared with all the internet traffic using the same access point as yourself. There are no managed IPTV services available in NZ yet.

Liquid Crystal Display. These are a particular type of flat panel television that is becoming a popular replacement for conventional CRT TVs. Most are suitable for displaying HDTV. See also Plasma.

MHEG-5 is an interactive digital television open standard. It has been developed by the Multimedia and Hypermedia Experts Group (MHEG). The raw MHEG-5 specification is called ISO/IEC 13522-5. The raw specification has to be accompanied by a “Profile” specification in order to be of any use for interactive TV. A few profiles have been defined and the most popular of them this the UK Profile. New Zealand has adopted this profile with a few extensions and this is now referred to as the NZ profile. Hong Kong have also adopted MHEG-5 as their interactive television middleware standard with a number of other countries trialling MHEG services.

An electronic gadget built into some digital receivers and digital recorders that allow it to be connected to a TV using an aerial (RF) lead instead of audio/video leads. It is useful for very old TVs with no a/v socket and for distributing the signal to multiple room in the home, but it means lower picture quality and mono sound. You can also buy external modulators from specialist electronics shores if your digital receiver doesn’t have one.

Motion Picture Experts Group - coordinates standards for the digital image processing used for broadcasting digital TV. They have developed several technical standards including MPEG2 (used for Freeview’s satellite service) and MPEG4 (used for Freeview’s terrestrial UHF service).

A digital TV multiplex is created by bundling together a group of digital TV channels so that together they fit into one broadcast stream. On analogue TV each TV channel occupied one whole stream. With digital TV it is possible to multiplex a number of TV, radio, and data services into one stream.

You can turn your computer into a digital TV and watch programmes on its screen. For this you need to either install a digital TV PC card (this means getting inside the computer) or, if you have a modern PC with a fast USB-2 socket, you can plug in a digital TV USB adapter. You use the supplied software to tune in and watch FTA digital TV.

A plasma TV is a particular type of flat panel TV (see also CRT and LCD). They are popular for larger screen TVs (such as 42” or greater). Many are suitable for displaying HDTV.

A general term for the way of delivering or receiving digital television. Typical platforms are terrestrial, satellite and cable.

A Personal Video Recorder (PVR) is a generic term for a digital receiver that records programmes directly onto a HDD (hard drive) and can store many hours of viewing. At Freeview we refer to them as a Digital Television Recorder (DTR).

Freeview approved DTRs are compatible with the MyFreeview|HD_® service.

Red Green Blue. This is a video signal format that provides high quality signals via an audio/video lead. Other formats - such as standard analogue broadcast video, or camcorder S-Video are slightly lower quality. RGB is generally used by digital receivers and DVD players.

A satellite dish is required to receive the Freeview satellite digital signal and to send this signal to your digital satellite receiver for decoding.

One way of connecting audio/video devises. It connects the picture and sound in one plug. A fully-wired SCART cable can carry RGB.

A Set-top-Box (STB) is a digital receiver in a stand alone box. It is a devise that receives digital television signals and converts them so it can be received on an existing (analogue) TV or VCR.

Set top box or digital receiver. The equipment that receives digital television and converts it so it can be received on an existing (analogue) TV or VCR.

The name used when broadcasters switch from analogue to digital by switching off the analogue transmitters. At this time you will have to have a digital TV (iDTV) or digital receiver to carry on watching TV. This date will be determined by the New Zealand Government, see here for more information.

TV transmissions - analogue or digital - that are broadcast over the air directly to your TV aerial from high sites around the country.

A UHF aerial is required to receive the Freeview HD_® digital signal and to send this signal to your HD capable digital terrestrial receiver for decoding.

This is the process by which a video scaler takes a low resolution (Standard Definition) video signal and increases it to a high resolution video output to fill a high definition TV. This can be done either by the broadcaster; transmitted in a high resolution, or by a Freeview approved high definition digital terrestrial receiver prior to the video output to the TV.

Video Cassette Recorder - the machine you have probably been recording and playing video tapes on for years. It records the analogue TV signal in fairly low quality. Because a VCR has only an analogue tuner built in, you need to use it with an external digital receiver (or digital TV) to record digital TV. The same applies for a DVD recorder.

To record from your digital receiver or digital TV you’ll need to ensure it is powered on and on the correct channel for the recording to be successful (note: you will not be able view a different channel while the recording is in progress).

We recommend using a MyFreeview_® Digital Television Recorder.  MyFreeview|HD allows you to pause, record and replay live TV.  You can record an entire series at the touch of a button and record two channels at once.  You can even record in High Definition.

This is a radio-transmitting device to distribute your TV picture and sound all around your house. It’s made up of a transmitter (sender) and receiver. The sender connects to the back of your TV, digital receiver, VCR or DVD player. The receiver connects to your second TV, for example, and picks up the transmitted signal in another room. By buying extra receivers you could pick up the signal in several other rooms. A video sender can also transmit back remote control signals so you can control the sending equipment. The main drawback of this distribution system is that you can view only the same programme on both the sending and receiving TV.

Video on Demand - programmes are delivered when you ‘demand’ (request) them. This is not currently available on Freeview.

The ratio of the width to the height of a widescreen TV picture is 16 to 9, often called 16:9 format. NZ’s main TV channels are now broadcasting their programmes in this widescreen format. Older programmes were in the narrower 4:3 format. If set up correctly, a widescreen TV and digital receiver should display the picture on your screen in 16:9 or 4:3 as appropriate for the programme. Films often have even wider formats. An older standard 4:3 TV and digital receiver combination usually means the sides of a widescreen picture are cut off.

This is a simple gadget designed to split your rooftop TV aerial two ways. You plug your aerial cable in one end and then run two extension leads from the output sockets. Because it splits the signal without amplifying it, you will end up with two weaker signals. But this should not be a problem if you have a good strong signal to start with. These splitters won’t work for weaker signals, or if you want to split your signal more than two ways. Then try an aerial distribution amplifier.