Montageanleitung anleitung Assembly Instruction tion English Deutsch GSS Grundig SAT Systems GmbH Beuthener Straße 43 D-90471 Nuernberg Terrestrial Digital QAM PTDQ 4001 ACLASS Phone: +49 (0) 911 / 703 8877 Fax: +49 (0) 911 / 703 9210 Email: info@gss.tv Internet: http://www.gss.tv KLASSE
Contents 1 Safety regulations...31 2 General information...31 2.1 Packing contents...31 2.2 Technical data...32 2.3 Description...33 2.3.1 Manual display of the software version...33 2.3.2 How the TP module works...33 2.3.3 The individual functions...34 3 Assembly...35 3.1 Inserting the cassette...35 3.2 Connecting the cassette...36 4 The operator control panel at a glance...37 4.1 Menu items...37 4.2 Operator control panel...37 5 Programming...38 5.1 Preparation...38 5.2 The menu at a glance...39 5.3 Programming the cassette...41 Selecting the strip / querying the software version...41 Setting the output channel...42 Frequency offset (fine tuning)...42 Setting the modulator...43 Hierarchical modulation...44 Setting the input channel/input frequency...45 Setting the QAM modulation value...46 Setting the station filter...48 Stuffing...49 Network Information Table (NIT)...51 TP module...52 Saving all settings...52 Setting channel strip B...52 6 Channel and frequency tables...53 6.1 Band I/III...53 6.2 Hyperband...54 6.3 Band IV/V...55 7 Technical terms in the digital transmission technology/satellite technology fields...56-30 -
1 Safety regulations Warning Assembly, installation and servicing must be carried out by an authorised electrician. Switch off operating voltage before the start of assembly or service work or pull out the mains plug. Install the system - in a dust-free, dry environment - so that it is protected from moisture, vapours, splashing water and damp - somewhere protected from direct sunlight - away from the immediate vicinity of heat sources - at an ambient temperature of < 50 C. Make sure the device is adequately ventilated. Do not cover the ventilation slots. Beware of short circuits! No liability is accepted for damage caused by faulty connection or inexpert handling. Observe the relevant norms, regulations and guidelines on the installation and operation of antenna systems. Earth the SAT receiver using the equipotential bonding rail in accordance with DIN EN 50083 und VDE 0855. Do not perform installation and service work during thunderstorms. Take action to prevent static discharge when working on the device. 2 General information 2.1 Packing contents 1 cassette PTDQ 4001 2 HF connection cables 1 Assembly instruction 1 measuring log ENGLISH - 31 -
2.2 Technical data The devices meet the following EU directives: 73/23/EEC, 89/336/EEC The product fulfils the guidelines and standards for CE labelling. HF input Frequency range: 177,5 226,5 MHz, 474 858 MHz Frequency raster: CCIR Level range: 30 80 dbµv (16 QAM 2/3, GI=1/4, 8k) KLASSE ACLASS HF output Channels: Frequency range: Channel raster: Output level: Output impedance: Fine tuning of the output signal: Connections HF input: HF output: Connection strip (10-pin): Socket RS232: S21 S41 306 MHz...466 MHz (Channel centre frequency) PAL CCIR Standard B/G Typ. 90 dbµv 75 Ω nominal ±4.00 MHz in 125 khz increments 2 IEC sockets 1 IEC socket, female for supply voltages and control circuits serial interface (Sub-D, 9 pin) for software updates using a PC or a notebook. Control panel software: min. software version V.30-32 -
2.3 Description The twin transmodulator cassette is a COFDM-QAM converter, which converts two COFDM 1) -modulated signals into two QAM 2) -modulated cable signals. The control of the cassette takes place via the head end. The twin cassette has two terrestrial inputs and a HF output. The cassette is equipped with two channel strips (A and B) and a TP module (Transportstream Processing). Each channel strip consists of a digital terrestrial tuner, a digital signal preparation unit and an output converter. The channel strips in the cassette are indicated in the control unit display by box A or box B. The prepared input signals are fed via the HF output socket to the HF output collector of the head end. The common output level of the channel strips A and B of the cassette can be set with the level regulator (max. 20 db) at the output collector of the head end. The TP module processes the data from the demodulated transport stream. This module can modify service information (NIT Network Information Table), increase data rates (stuffing) and delete individual stations from the transport stream. After the head end has been switched on, the software version of the control unit is displayed briefly in the two-line LC display. Approximately five minutes after the last button has been pressed, the display switches off automatically or the software version of the control unit is displayed. The Cassette is designed for use in the head ends PSU 8, PGT 8 and PSU 12. 2.3.1 Manual display of the software version If necessary, you can call up the display of the software version of the control unit manually: Hold down any two keys of the control unit simultaneously until the display goes dark and the software version, e.g. V.30, is displayed. 2.3.2 How the TP module works When converting the COFDM-modulated signal to a QAM-modulated cable signal, the demodulated data stream can be accessed via the integrated TP module. This data stream, also called transport stream, contains several stations in all their components (video, audio, data and service information), which can be changed using the TP module. ENGLISH 1) COFDM = Coded Orthogonal Frequency Division Multiplexing 2) QAM = Quadrature Amplitude Modulation - 33 -
2.3.3 The individual functions Station filter Individual stations can be suppressed. This reduces the data rate and, consequently, the output symbol rate. Stuffing The transport stream can be padded out using what is known as zero data. This increases the data rate and, consequently, the output symbol rate. Changing the output symbol rate suitably alters the bandwidth used (halving the output symbol rate roughly halves the bandwidth at the output). Changing service information The transport stream contains data in the form of tables which the receivers evaluate and require for convenient use. The TP module can change the Network Information Table (NIT). The NIT contains data which the set-top box needs for the automatic search function. Explanation of the term symbol rate High-quality modulation methods like QPSK and QAM can encrypt several bits as a single transferred and received symbol. The user data stream contains the audio and video signals of a station and is thus permanently assigned. If the value of the modulation and therefore the number of bits per symbol is increased, the symbol rate falls compared to the user bit rate. Formulae for calculating the output symbol rate SR (A) at a fixed input symbol rate SR (E) and FEC. 256-QAM: 128-QAM: 64-QAM: 32-QAM: 16-QAM: 4-QAM: SR (A) = FEC x 1/4 x SR (E) SR (A) = FEC x 2/7 x SR (E) SR (A) = FEC x 1/3 x SR (E) SR (A) = FEC x 2/5 x SR (E) SR (A) = FEC x 1/2 x SR (E) SR (A) = FEC x 1/1 x SR (E) Example: Output symbol rate 64-QAM, FEC= 3/4, Input symbol rate SR (E) = 27500 kilosymbols per second SR (A) = 3/4 x 1/3 x 27500 kilosymbols/s = 6875 kilosymbols/s - 34 -
C101 L104 L100 L101 L103 C100 BREITBA +24 ROT GRUEN +18V Anschl. Note: If no FEC is stated in the station lists, it can be assumed to be FEC = 3/4. 3 Assembly 3.1 Inserting the cassette Warning Before inserting or changing cassettes, pull the mains plug of the head end out of the mains socket. Unscrew the fastening screws from the bracket in the head end. Insert the cassettes into a free slot and push it into the housing. Align the cassette and gently make it contact with the connections of the circuit board and the HF bus bar. Fasten the cassette with the 1 screws. LNC- +18V INPUT OUTPUT OUTPUT INPUT ENGLISH CASSETTE CASSETTE CASSETTE CASSETTE CASSETTE CASSETTE CASSETTE CASSETTE CASSETTE CASSETTE CASSETTE CASSETTE - 35 -
3.2 Connecting the cassette Plug the HF input cables into the HF input sockets INPUT A 3 (channel strip A) and INPUT B 1 (channel strip B). Connect the head end to the mains power supply. > The cassette is now ready for operation. It is connected to all required supply voltages and data cables! Note: The operating software of the cassette can be updated via the socket RS232 5 (9-Pin-Sub-D) by means of a PC or notebook. Use the BE-Flash software as the update software. You can find the current operating software of the cassettes on the website www.gss.tv. - 36 -
4 The operator control panel at a glance 4.1 Menu items Program the cassette using the buttons on the control unit of the head end. The two-line display of the control unit then shows the menus. You can select the following menu items with the button: cassette, channel strip output channel, frequency offset modulator settings input frequency symbol rate, FEC QAM modulation value station filter stuffing NIT TP module functions BE Remote V. 19 PROFESSIONAL More detailed information on using the menu can be found in the settings described below 4.2 Operator control panel You can individually select the menus and menu items step-by-step using the keypad of the head end: scrolls forward through the menu / select parameters in the menus set values, initiate actions selects sub-menus M saves all entries ENGLISH The parameters to be set are displayed underlined (cursor). - 37 -
5 Programming 5.1 Preparation Notes: The cassette generates an equally powerful HF carrier on the video carrier frequency of the channel. In this way, the cassette s level can also be set with an analogue TV test receiver set to the video carrier frequency of the channel. In order to prevent interference within the head end and the cable system, the output level of the digital cassette must be lowered by around 8 db compared to analogue cassettes. Connect the test receiver to the HF output OUTPUT of the head end. Set the output channel of the digital cassette (see page 42) and adjust the TV test receiver to this channel. Switch on the modulator if necessary. Balance the output levels of the channel strips A and B if the difference in level is 1 db (see chapter Setting the modulator, page 43). Measure the output level of the analogue cassettes and, if necessary, tune it to a uniform output level. - 38 -
5.2 The menu at a glance Ein/On BE Remote V. 30 PROFESSIONAL t > 10 s Bx 1A TWIN-SAT C5-12,S3-24 C07 + Box 2 DVB-T/QAM S21-S41 *SN S21 + Bx 1A TWIN-SAT Böx 4 TWIN-SAT Box 3 TWIN-SAT C5-12,S3-24 C07 C5-12,S3-24 C07 C5-12,S3-24 C07 A / B DVB-T/QAM S21-S41 *SN S21 Bx Bx 2A 3a VERSION: VERSION: PTDQ TP-MODUL: 4001 V.01 /1.01 S21 OUTPUT: (306,00) S21 0 OUTPUT: (306,00) -64 +64 OUTPUT: LEVEL CONTROL OUTPUT: Modulator: on on / off: LEVEL OUTPUT: HF OUT: 0 0-7 OUTPUT: RANDOM 6875 kbd OUTPUT: Spectrum normal normal / inverse ENGLISH - 39 -
PRIORITY INPUT: high high / low INPUT: CCIR INPUT: FREQUENCY C40 INPUT: (? ) t > 2 s C40 Fine 0 INPUT: (? ) 626.00 MHz INPUT: + / (? ) / QAM-MODE: 64-QAM SR-6875 + / Prg. FILTER: Filter off + Tv + 01/12 / AUDIO 3Sat + / STUFFING: SR=6875 (3273) on + / / on NIT: Make on / off + / / + / M Box 2 DVB-T/QAM S21-S41 *SN S21-40 -
5.3 Programming the cassette Switch on the head end > The processor reads the cassette s data (approx. 10 seconds) > The display shows the software version (e.g. V.30) Ein / On BE Remote V. 30 PROFESSIONAL t > 10 s Bx 1A TWIN-SAT C5-12,S3-24 C07 + Box 2 DVB-T/QAM S21-S41 *SN S21 + Bx 1A TWIN-SAT Böx 4 TWIN-SAT Box 3 TWIN-SAT C5-12,S3-24 C07 C5-12,S3-24 C07 C5-12,S3-24 C07 Select the cassette you want to program by (box no.) by repeatedly pressing the button. By pressing, activate channel strip A. DVB-T/QAM S21-S41 *SN S21 Selecting the strip / querying the software version > The display shows e.g. the menu DVB-T/QAM. Bx stands for cassette (box) 2 for cassette 2 A for channel strip A Bx Bx 2A 3a VERSION: VERSION: PTDQ TP-MODUL: 4001 V.01 /1.01 A / B ENGLISH - 41 -
To query software versions: - Software version of the cassette: press the button once. - Software version of the TP module: press the button twice. - Return to main menu: press the button again. By pressing, activate channel option OUTPUT:. Setting the output channel S21 OUTPUT: (306,00) S21 S 41: t > 2 s S21 0 OUTPUT: (306,00) -64 +64 By pressing, set the desired output channel. > The channel range that can be set depends on the type of cassette used. Frequency offset (fine tuning) Warning: Only change the frequency offset in exceptional circumstances and where there is a well-founded reason for doing so, since once you change it, all connected televisions of the cable system must be adjusted to match it by means of corresponding fine-tuning corrections. Press and hold down the button until 0 also appears in the display. By pressing the buttons, set the offset (e.g. SelecPlex, see page 50). Press the button: > The menu LEVEL CONTROL is activated (s. page 38). - 42 -
Setting the modulator OUTPUT: OUTPUT: LEVEL CONTROL Modulator: on on / off: LEVEL OUTPUT: HF OUT: 0 0-7 OUTPUT: RANDOM 6875 kbd Spectrum OUTPUT: normal normal / inverse Press the button. > The menu OUTPUT: Modulator appears in the display. By pressing the buttons, switch the modulator (HF output) off or on. Press the button. > OUTPUT: LEVEL HF OUT: appears in the display. (s. page 38). Compare/Adjust the output levels of the channel strips: Select the channel strips A and B and by pressing adjust the higher output level of one channel strip to the lower output level of the other channel strip incrementally from 0 to 7 db. Press the button. > OUTPUT: RANDOM is shown in the display. The cassette generates a QAM signal for testing, without there having to be an input signal. ENGLISH - 43 -
> In the secong menu line, the corresponding output symbol rate e.g. 6875 kbd (= 6875 kilosymbols per second) is shown. Press the button. > The display shows the OUTPUT: Spectrum menu. Note: For exceptions and older digital cable receivers, the spectral position of the user signal can be inverted. By pressing, set the spectral position inverse / normal. Press the button. > Back to main menu Press the button. > The display shows the INPUT PRIORITY menu. Hierarchical modulation PRIORITY INPUT: high high / low By pressing, set to high or low (Not relevant in the case of standard modulation - see also chapter 7). Press the button. > The display shows the INPUT: CCIR menu. - 44 -
Setting the input channel/input frequency INPUT: CCIR INPUT: FREQUENCY C40 INPUT: (? ) 626.00 MHz INPUT: / (? ) + / By pressing, select the menu Input channel or Input frequency. Press the button. Setting the channel By pressing, select the input channel Press the / button for > 2 seconds t > 2 s C40 Fine 0 INPUT: (? ) If necessary, press to fine tune the input channel. Setting the frequency Set the input frequency by pressing. > Scroll through the various stages of the frequency displayed by pressing /. Note: If a question mark? appears in the second line of the display, there is no input signal present. Check the configuration of the antenna system and head end as well as the preceding settings of the cassette in question. ENGLISH Press the button. > The display shows the QAM-MODE menu. - 45 -
Setting the QAM modulation value The QAM-MODE menu appears in the display. The second line of the menu shows the corresponding output symbol rate, for example 6875 kilosymbols per second. QAM-MODE: 64-QAM SR-6875 + / Note: The output symbol rate of connected digital cable receivers must be set to this value (e.g. 6875 kilosymbols per second) in the case of manual station search. Note: Normally, 64 QAM are transmitted on the cable network. If a question mark? appears in the second display line, the cassette cannot generate an output signal. QAM-MODE: 64-QAM SR-? Check the configuration of the antenna system and head end as well as the preceding settings of the cassette in question. Maximum / Minimum symbol rate The cassette can only generate a maximum symbol rate of 7000 kilosymbols per second. A very high input symbol rate induced by a station can lead to the output symbol rate of 7000 kilosymbols per second being exceeded. Input symbol rates which are too low can also cause problems. Some digital receivers only process a preset minimum symbol rate, or the cassette limits this range to 1000 ki lo symbols per second. - 46 -
> Error appears in the second line of the display. QAM-MODE: 64-QAM Error This means that the output symbol rate lies above or below the permissible value. Setting a higher QAM mode. > The output symbol rate is restricted to the permissible level of < 7000 kilosymbols/s. An output symbol rate of > 64 QAM places a large burden on the cable network. Due to noise, delay and frequency response problems, a reception of the converted output signal can be impeded. Setting a lower QAM mode. > The output symbol rate increases to the permissible level. The built-in TP module allows you to increase the symbol rate (stuffing) without changing the QAM assignment (see also Stuffing on page 49). Press the button. > The FILTER menu appears in the display. ENGLISH - 47 -
Setting the station filter The default setting for the station filter is off. Prg. FILTER: Filter off + Tv + 01/12 / AUDIO 3Sat + / Press the button. > Indication 01/12 means: Station 1 of 12 stations found. > Indication + means: The displayed station is switched on. > All the stations are displayed along with their names, content (TV, radio, data) and serial number. Select the stations one after the other: press /. > Switch off (remove) a station by pressing the button > Switch the station back on again by pressing the button. Save changes and activate the station filter: Press the button. > The filter is activated ( on ). The corresponding PID s (Audio, Video, Text) are removed from the data stream and the tables PAT and SDT are updated. The band width of the data stream gets smaller. > The station filter remains deactivated ( off ) if no station was removed. > To break off station selection: press the AUDIO button (filter off ). Switch off the stations that are switched on ( on ): press the button ( off ). Test the status of the individual stations: If the filter is switched on, press the VIDEO button. In this mode you can switch back to deleted stations or delete further stations by pressing the buttons. - 48 -
- If no station is found, the error message Program table fatal Error!!! appears. Check the configuration of the antenna system and head end as well as the preceding setting of the Cassette in question. Press the button. > The STUFFING menu appears in the display. Stuffing Applications for the station filter and stuffing Reception from a station with a very high symbol rate. This high input symbol rate may mean the QAM has to be set to 256. Transfer at 256-QAM is very critical due to reflections, noise and distortion. In this case, stations which are not needed should be filtered out. The data rate is lowered and can be switched to 64 QAM. Procedure: Set 64 QAM (ignore error message!) Filter out a sufficient number of unnecessary stations Set stuffing to a new output symbol rate Reception from a station with a very low symbol rate. (SCPC station) The extremely low data rate means that the output symbol rate is very low. If there are reception problems, set stuffing to a higher value. Defined symbol rates Some cable operators specify a fixed symbol rate (e.g. 6900 kilosymbols per second). ENGLISH - 49 -
Bandwidth-efficient assignment of cable channels with low bandwidths (SelecPlex ) Channels with low bandwidths are the result of filtering out stations which are not required. These narrow channels can then be arranged to save space. To do this, activate fine tuning in the Output channel menu (assignment outside the official channel raster). STUFFING: SR=6875 (3273) on + / / SR=6875 (= number 1): output symbol rate STUFFING: SR=6875 (3273) off Zahl 1 Zahl 2 Number 1 Number 2 (3273) (= number 2): The current measured output symbol rate. If the station filter is activated, this value is lower than the first number. The value fluctuates, since the data rates of individual stations are dynamically modified by the broadcasters. Set number 1 by pressing the buttons. The value set corresponds to the new output symbol rate. > Scroll through the various stages of the frequency display by pressing /. By pressing the button, scroll to off and by pressing, switch on ( on ) stuffing. - 50 -
Note: Increase the value of number 1: With the station filter on / off, the first number can be increased to any value up to 7000. Reduce the value of number 1: With the station filter on, the first number can be decreased. To do this, observe the second number for 30 seconds and note the highest value. Add roughly 10 % to this value. Do not decrease the first number lower than this. Press the button. The NIT menu appears in the display. Network Information Table (NIT) on NIT: Make on / off + / / + / To switch NIT on/off ( on / off ): press the button. Select by pressing Make and activate with. > The cassette fetches all the information it needs (output frequencies, output symbol rates etc.) to generate the NIT from all the QAM cassettes. This process may take a few seconds. The display shows: Making.... > Then the NIT is generated, added and sent to all QAM cassettes. The other QAM cassettes also add this new NIT. The status of all QAM cassettes in the NIT menu changes to on. To deactivate the new NIT: press the and buttons. > The original NIT is restored. Note: The cable NITs of the other cassettes remain activated. When it is reactivated ( on ), the previously generated NIT is added again. If you have changed parameters in the meantime, you must select Make to generate a new, up-to-date NIT. ENGLISH - 51 -
TP module Note: All QAM cassettes must be equipped with a TP module. Cassettes without TP modules are not taken into consideration during the NIT setting. All QAM cassettes must be set and ready for reception. If the NIT is activated ( on ) and parameters are modified and saved, a warning appears in the display: Attention!!! Make NIT!!!. In this case, you must create a NIT ( Make ). The NITs of all the QAM cassettes in the head end are thus automatically updated. Saving all settings M Box 2 DVB-T/QAM S21-S41 *SN S21 Press the M button. > Back to select the cassettes A (page 41). > The new settings are saved permanently. > If functions of the TP module are activated, their status is shown in the second line of the display: P station filter on S stuffing on N NIT changed Functions that are not active are indicated by a star ( * ). Box 2 DVB-T/QAM S21-S41 *SN S21 Setting channel strip B Press the button. > Carry out with channel strip B all the settings described for channel strip A. - 52 -
6 Channel and frequency tables 6.1 Band I/III ENGLISH Kanal Channel Kanalmittenfrequenz Channel centre frequency [MHz] Bildträgerfrequenz Picture carrier frequency [MHz] Kanal Channel Kanalmittenfrequenz Channel centre frequency [MHz] Bildträgerfrequenz Picture carrier frequency [MHz] C 2 51.00 48.25 C 3 58.00 55.25 C 4 65.00 62.25 S 2 115.00 112.25 S 3 122.00 119.25 S 4 129.00 126.25 S 5 136.00 133.25 S 6 143.00 140.25 S 7 150.00 147.25 S 8 157.00 154.25 S 9 164.00 161.25 S 10 171.00 168.25 C 5 178.00 175.25 C 6 185.00 182.25 C 7 192.00 189.25 C 8 199.00 196.25 C 9 206.00 203.25 C 10 213.00 210.25 C 11 220.00 217.25 C 12 227.00 224.25 S 11 234.00 231.25 S 12 241.00 238.25 S 13 248.00 245.25 S 14 255.00 252.25 S 15 262.00 259.25 S 16 269.00 266.25 S 17 276.00 273.25 S 18 283.00 280.25 S 19 290.00 287.25 S 20 297.00 294.25-53 -
6.2 Hyperband Kanal Channel Kanalmittenfrequenz Channel centre frequency [MHz] Bildträgerfrequenz Picture carrier frequency [MHz] S 21 306.00 303.25 S 22 314.00 311.25 S 23 322.00 319.25 S 24 330.00 327.25 S 25 338.00 335.25 S 26 346.00 343.25 S 27 354.00 351.25 S 28 362.00 359.25 S 29 370.00 367.25 S 30 378.00 375.25 S 31 386.00 383.25 S 32 394.00 391.25 S 33 402.00 399.25 S 34 410.00 407.25 S 35 418.00 415.25 S 36 426.00 423.25 S 37 434.00 431.25 S 38 442.00 439.25 S 39 450.00 447.25 S 40 458.00 455.25 S 41 466.00 463.25-54 -
6.3 Band IV/V Kanal Channel Kanalmittenfrequenz Channel centre frequency [MHz] Bildträgerfrequenz Picture carrier frequency [MHz] Kanal Channel KanalmittenfrequenzChannel centre frequency [MHz] Bildträgerfrequenz Picture carrier frequency [MHz] C 21 474.00 471.25 C 22 482.00 479.25 C 23 490.00 487.25 C 24 498.00 495.25 C 25 506.00 503.25 C 26 514.00 511.25 C 27 522.00 519.25 C 28 530.00 527.25 C 29 538.00 535.25 C 30 546.00 543.25 C 31 554.00 551.25 C 32 562.00 559.25 C 33 570.00 567.25 C 34 578.00 575.25 C 35 586.00 583.25 C 36 594.00 591.25 C 37 602.00 599.25 C 38 610.00 607.25 C 39 618.00 615.25 C 40 626.00 623.25 C 41 634.00 631.25 C 42 642.00 639.25 C 43 650.00 647.25 C 44 658.00 655.25 C 45 666.00 663.25 C 46 674.00 671.25 C 47 682.00 679.25 C 48 690.00 687.25 C 49 698.00 695.25 C 50 706.00 703.25 C 51 714.00 711.25 C 52 722.00 719.25 C 53 730.00 727.25 C 54 738.00 735.25 C 55 746.00 743.25 C 56 754.00 751.25 C 57 762.00 759.25 C 58 770.00 767.25 C 59 778.00 775.25 C 60 786.00 783.25 C 61 794.00 791.25 C 62 802.00 799.25 C 63 810.00 807.25 C 64 818.00 815.25 C 65 826.00 823.25 C 66 834.00 831.25 C 67 842.00 839.25 C 68 850.00 847.25 C 69 858.00 855.25 ENGLISH - 55 -
7 Technical terms in the digital transmission technology / satellite technology fields CA (Conditional Access) An encrypted digital channel (conditional access) can only be viewed with the CA module for the encryption system in conjunction with the corresponding smart card. The smart card contains all of the necessary subscriber and channel data for the authorisation and enabling of the corresponding channel provider. The digital encryption systems most commonly in use in Europe are: Conax, CryptoWorks, Irdeto, Nagravision, Seca and Viaccess. CI (Common Interface) The common interface slot (CI) is the interface for DVB receivers, into which a CA module of the various encryption systems can be inserted. DVB (Digital Video Broadcast) With DVB, the limited resources of terrestrial transmitters and satellite transponders can be used in a considerably more efficient manner. It is possible to store 6 digital TV and radio channels on one channel/transponder without compromising quality. FEC (Forward Error Correction) FEC is a standardised error protection system for digital television transmissions. In this process, redundant data (only back-up data containing no picture or audio data) is transmitted along with the original picture and audio data. This is necessary since there is no saved data protocol between the transmitter and the satellite receiver. If transmission faults occur, the receiver can reconstruct the missing information using the redundant data. The FEC describes the relationship of original picture and audio data to redundant data. An FEC of 3/4 states that a data volume consisting of 3/4 original data and 1/4 redundant data is being transmitted. Hierarchical modulation In order to attain with less field strength a greater range for broadcasters, with DVB- T so-called hierarchical modulation is used. In this process, several data streams are modulated onto a DVB-T data stream using Quadrature Amplitude Modulation (QAM). The robust High Priority data stream (HP) with a lower data rate is modulated onto the more sensitive Low Priority data stream, which possesses a higher data rate. In good reception conditions, the receivers can receive both data streams; in poorer reception conditions, only the HP portion. Several receivers can be supplied simultaneously with various services via one channel. MCPC (Multi Channel Per Carrier) This is a common process for accomodating several picture and audio channels on one carrier per transponder. - 56 -
MPEG (Motion Picture Expert Group) This internationally recognised norm group has created the basis for digital television (DVB) and many other interactive digital services. Digital television as it stands works with MPEG-2, where HDTV is also defined (see also ISO norm - ISO 13818-1). PID (Program ID) To be able to filter out a single channel from the data stream of an MCPC carrier, identity codes are transmitted for every channel for picture and audio transmissions (i.e. video PID and audio PID). The receiver has saved the PIDs in its channel list for every station and can route the correct data to the television. The PIDs are determined anew during every automatic search. In order to view a certain station, it may be necessary (only in exceptional cases) with some receivers to enter the PIDs manually. QPSK (Quadrature Phase Shift Keying) Quadrature Phase Shift Keying With QPSK, the carrier oscillation can take in four discrete phase conditions, which are allocated the four possible combinations or two consecutive bits of the binary code signal. This makes it possible to transmit two bits with one phase condition. Correspondingly, carrier oscillation phase jumps of 90, 180, 270 and 360 (0 ) are possible. The amplitude and frequency of the carrier oscillation therefore remain constant. SCPC (Single Channel Per Carrier) In an SCPC process, only one digital picture or audio channel is on one carrier. A number of carriers can be stored on one transponder. SR (Symbol Rate) The symbol rate specifies at which speed data is to be sent. The receiver must synchronise to this speed. Symbol rates between 22000 and 27500 kilosymbols per second are common for MCPC channels; SCPC channels work with symbol rates between 2000 and 7000 kilosymbols per second. Smart card Access/Authorisation card of a channel provider with which the paying subscriber can view the encrypted satellite channels of this provider. The smart cards contain a chip, in which all necessary subscriber and channel data for the authorisation and enabling of encrypted satellite channels are saved. Cyclical information is sent for all subscribers via the transmitter. The CA module filters the relevant information for the subscriber noted on the card and checks their authorisation. ENGLISH - 57 -
Änderungen vorbehalten. Technische Angaben ohne Gewähr. 265009411400 Alterations reserved. Technical data E. & O.E. GSS GmbH 26062005