| Annex A |
Bouquet | A collection of services (TV, radio, and data, or any combination of |
| the three) grouped and sold together, and identified in the SI as a |
| group. A single service may be in several bouquets. |
| coded using |
| frames (forward prediction) and/or future I or P frames (backward |
| prediction). B frames are not used in any prediction. |
BPSK | Binary Phase Shift Keying: A data modulation technique. |
Buffer | A memory store used to provide a consistent rate of data flow. |
BW | Bandwidth: The transmission capacity of an electronic line such as |
| (among others) a communications network, computer bus, or |
| broadcast link. It is expressed in bits per second, bytes per second |
| or in Hertz (cycles per second). When expressed in Hertz, the |
| frequency may be a greater number than the actual bits per second, |
| because the bandwidth is the difference between the lowest and |
| highest frequencies transmitted. High bandwidth allows fast |
| transmission or |
Each byte is delivered separately in the ASI transport stream, with | |
| stuffing data added between the Bytes to increase the data rate to |
| 270 Mbps. See DVB Document A010 rev. 1, Section B3.3, (ASI) |
| |
CA | Conditional Access: The technology used to control the access to |
| viewing services to authorized subscribers through the transmission |
| of encrypted signals and the programmable regulation of their |
| decryption by a system such as viewing cards. |
CAT | Conditional Access Table: Part of the |
| Information (PSI) data. Mandatory for |
| in use. |
The portion of the electromagnetic spectrum, which spans the | |
| frequency range of approximately 4 GHz to 6 GHz. Used by |
| communications satellites. Preferred in tropical climates because it |
| is not susceptible to fading. |
CCIR | See: |
CCITT | See: |
Channel | a narrow range of frequencies, part of a frequency band, for the |
| transmission of radio and television signals without interference from |
| other channels. |
| In the case of OFDM, a large number of carriers spaced apart at |
| precise frequencies are allocated to a channel. |
Channel Coding | A way of encoding data in a communications channel that adds |
| patterns of redundancy into the transmission path in order to |
| improve the error rate. Such methods are widely used in wireless |
| communications. |
EN/LZT 790 0005 R1A |