RDS, Radio Data System
Broadcasting of text information via VHF
Set-top box
Receiver placed on top of the television set (set-top) which converts digital TV and radio signals to analogue so that the programmes can be used in normal receivers. There are currently two types of set-top boxes on the market: set-top boxes with open API interfaces (multicrypt) and a number of free slots for smartcard readers (common interface) and set-top boxes with closed interfaces (simulcrypt) and integrated readers. The latter are usually individual operators' proprietary systems which - unlike equipment with open interfaces - permit only limited reception of other operators' programmes. The set-top box is also used to decode pay programmes using a smartcard. It is expected that set-top boxes will be integrated directly into television sets in future. More recent set-top boxes have an output port for a return channel (e.g. telephone line) for direct access to the internet.
Single Frequency Networks (SFN)
Digital broadcasting signals are transmitted on the same frequency within the coverage area of a number of transmitters. Unlike multifrequency transmission where using frequencies that are too close to each other leads to interference (interference from reflections), with single frequency networks (SFN) these reflections (e.g. from mountains or tall buildings) are used to improve reception as the receiver can simultaneously evaluate the signals from multiple transmitters (multipath use). SFNs also contribute to efficient use of the frequency spectrum.
Smartcard
Card in the form of a credit card which releases pay programmes after it is inserted in the set-top box. Smart cards can be purchased with a fixed credit or are available as pay-as-you-go, for example by paying a fixed or variable fee (e.g. per film). In this case, payment is made via the broadcast network. For copyright reasons, the SRG also sells a smartcard for decoding SRG programmes via satellite. This card is available on payment of a one-off charge of CHF 50 and is only for use in Switzerland.
Stationary reception
With stationary reception, the receiver remains static in a particular location.
T-DAB
Acronym for Terrestrial Digital Audio Broadcasting - standardised procedure for the digital transmission of radio signals developed in the EU research initiative EUREKA 147. T stands for terrestrial broadcasting. Unlike DVB, T-DAB is not received by the set-top box but by a special DAB radio.
Terrestrial broadcasting
Wireless, terrestrial transmission of signals using specified frequencies; bounded by cable or satellite transmission.
Transmission mode
After multiplexing, digital programme data streams are separated into a large number of individual parts at the transmitter using a special modulation procedure (Codes Orthogonal Frequency Division Multiplex, COFDM) and transmitted together with coding signals on the same number of individual carrier frequencies. At the receiver, the data is recombined in the correct order by means of the information from the coding signals, corrected for transmission errors and converted to analogue.
VHF
Very High Frequency, the frequency range 88.5 - 108.0 MHz; currently, the normal method for broadcasting stereo radio programmes using analogue techniques (see also FM).
Wide-screen format
New television picture format with an aspect ratio of 16:9. The standard picture format in the past was an aspect ratio of 4:3 (corresponding to 12:9).
