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Paradise Datacom P300-IBS, Руководство по установке и эксплуатации

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P300H

P300 Modem Installation and Operating Handbook

Page 198

The remaining values of N cannot have Timeslot ID Maintained by groups of 1, 2, or 4 frames, these are
collectively know as the `Odd values of N`:

`Odd values of N`: N = 7, 9, 11, 13, 14, 17, 18, 19, 21, 22, 23, 25, 26, 27, 28, 29, 31

Most previous equipment could not provide timeslot ID maintenance for these `odd values of N`, however
the P300 when equipped with the Extended D/I feature uses a derivative of the IBS CAS Multiframe (see
later section "CAS Multiframe") to provide timeslot ID maintenance for even these remaining values of N.

Signalling Systems Introduction: CCS, CAS & RBS
Signalling systems are used to convey call status on PCM systems, call status is information such as Busy,
Idle, Ring tone, Dialling etc. 

Common Channel Signalling (CCS)
Some PCM systems us a`Common Channel Signalling` (CCS), where a whole timeslot is allocated to carry
the signalling function between the ends of the link (with protocols such as `Signalling system No 7` etc
running within that 64kbps channel). Common Channel Signalling is used on both 1544kbps (T1) and
2048kbps (E1) systems, although different signalling systems run on the common channel (of course !)

Channel Associated Signalling
Some E1 PCM systems use Channel Associated Signalling (CAS), where a low rate data signalling
channel is provided uniquely for each timeslot. ITU-G.704 defines these signalling channels as comprising
of four bits (named `abcd`) which are sent every 16th frame, resulting in a channel of 2kbps. There is an
individual 2kbps signalling channel for each of the 30 PCM channels (timeslots 1-15 and 16-31) and these
are carried sequentially in pairs in TS16 (there is no signalling channel for TS0 nor TS16, as TS0 is
reserved for the Frame Alignment Word, and TS16 carries the signalling for the other timeslots).

Robbed Bit Signalling (RBS)
Robbed bit signalling is a technique used on T1 PCM bearers whereby signalling is conveyed by stealing
the signalling bandwidth from the 64kbps timeslot to which it relates. Once every 6 frames one bit (the least
significant bit) of the 8 bits per timeslot is `stolen` and used to convey signalling. In T1-D4 (which has a 12
frame terrestrial multiframe) this gives two signalling bits `ab`, and in T1-ESF (which has a 24 frame
terrestrial multiframe) this gives four signalling bits `abcd`. The frames in which the bit is robbed are
synchronised to the terrestrial multiframe as follows: T1-D4: 6th & 12th, T1-ESF 6th, 12th, 18th, 24th.

Stealing the LSB every sixth frame was acceptable when PCM signals conveyed primarily PCM audio as
it made a negligible difference to the audio quality. However when the PCM network was later used to
convey data not just PCM encoded voice, only 56kbps of data could be conveyed (using 7 bits per
timeslot), as it was difficult to guarantee the signal would not pass through a link using Robbed Bit
Signalling where the 8th bit would be overwritten every 6th frame, causing errors on the 64kbps data.

Signalling Over Satellite

Common Channel Signalling (CCS)
With Common Channel Signalling, the whole 64kbps signalling channel (timeslot) must be conveyed from
one end of the link to the other and typically this is done on sub primary order satellite circuits (thin routes)
by selecting the timeslot carrying the CCS for Drop/Insert as with other data timeslots. Special action is
required with CCS, as the equipment at both ends of the link needs to be configured for the ` thin route`
over the satellite so it does not dynamically allocate traffic to a timeslot which is not passed over satellite
link !

Содержание P300-IBS

Страница 1: ...ise Datacom LLC 1 Wheaton Road 1012 E Boal Avenue Witham Essex CM8 3TD England Boalsburg PA 16827 U S A Phone 01376 515636 Int 44 1376 Phone 814 466 6275 Int 1 814 Fax 01376 533764 Fax 814 466 3341 http www paradisedata com IMPORTANT NOTE THE INFORMATION AND SPECIFICATIONS CONTAINED IN THIS DOCUMENT SUPERSEDE ALL PREVIOUSLY PUBLISHED INFORMATION CONCERNING THIS PRODUCT PARADISE DATACOM maintains a...

Страница 2: ... 5 2 VISUAL INSPECTION OF EQUIPMENT 38 5 3 INTERFACE OPTIONS 38 5 4 IF INTERFACE 38 5 5 POWER UP 38 6 MENU SYSTEM 39 6 1 INTRODUCTION 39 THE 1 MINUTE GUIDE TO FRONT PANEL OPERATION 39 6 2 MENU STRUCTURE DIAGRAMS 40 6 2 1 Full Menu Structure Page 1 6 Main Status Change 41 6 2 2 Full Menu Structure Page 2 6 Main Monitor Info 42 6 2 3 Full Menu Structure Page 3 6 Main Log Test Setup Action Help 43 6 ...

Страница 3: ...x Modulator AUPC TOLERANCE Menu 73 6 6 24 Change Tx Modulator AUPC COMMS LOST ACTION Menu 73 6 6 25 Change Tx Rx ESC AUX BA Menu 74 6 6 26 Change Tx Rx ESC Aux BA DEFINE IDR Menu 75 6 6 27 Change Tx Rx ESC Aux BA DEFINE IBS Menu 76 6 6 28 Custom IBS Overhead Allocation 78 6 6 29 Change Tx Rx ESC Aux BA ASYNC ESC Menu 79 6 6 30 Change Tx Rx ESC Aux BA Config Async BAUD RATE Menu 80 6 6 31 Change Tx...

Страница 4: ... SAT Menu 103 6 10 8 Change User Opt Operation ALARMS Menu 104 6 10 9 Change User Opt DISPLAY Menu 104 6 10 10 Change User Opt AGC Output Menu 104 6 11 CHANGE TIME DATE MENU 105 6 12 MONITOR MENU 106 6 12 1 Monitor DEMOD PERFORMANCE Menu 106 6 12 2 Monitor TERRESTRIAL BER Menu 106 6 12 3 Monitor CARRIER ID s Menu 107 6 12 4 Monitor DISTANT Eb No BER Menu 107 6 12 5 Monitor AUPC Menu 108 6 13 INFO ...

Страница 5: ...UES OF RS N K 134 8 5 NOTES ON DATA RATES SYMBOL RATES 135 8 6 DETERMINING EXACT MAXIMUM ESC BAUD RATES 136 8 7 CLOSED NETWORK PLUS ESC 137 8 7 1 Overhead Rates 137 8 7 2 Closed Network Plus ESC via the Custom Service menu 138 8 8 CROSS REFERENCE TO SDM300 D I FRAMING MODES 139 8 9 V 35 SCRAMBLERS 141 8 10 INTERWORKING DIFFERENT MANUFACTURERS EQUIPMENT 142 8 11 INTRODUCTION TO AUPC AUTOMATIC UPLIN...

Страница 6: ...IRE SOON 182 APPENDIX C4 ASYMMETRIC LOOP TIMING 182 APPENDIX C5 UPGRADE AVAILABLE 182 APPENDIX C6 FEATURES NOT AVAILABLE 182 APPENDIX D REMOTE M C 183 REMOTE M C PROTOCOL 183 Summary 183 Character Format Baud Rate 183 Electrical Interface 183 Message Structure 184 Message Categories 185 List of All Remote M C Messages 186 APPENDIX E CUSTOMER SPECIFIC FEATURES 189 RELAY MODE SETTING 189 FAULT MODE ...

Страница 7: ... ensure that the following points are observed 1 The equipment MUST BE OPERATED WITH ITS COVER ON AT ALL TIMES If it is necessary to remove the cover for any reason then you must ensure that the cover is correctly refitted before normal operation 2 Damage to the front panel keyboard membrane or mechanical damage to the chassis could invalidate compliancy Please contact the factory if damage occurs...

Страница 8: ...ment is classified in EN 60950 as a pluggable equipment class A for connection to the mains supply As such it is provided with a mains inlet cord suitable for use in the country of operation In normal circumstances this will be of an adequate length for installation in the rack If the mains cable proves to be too short then any replacement must have a similar type fuse if fitted and be manufacture...

Страница 9: ...c relay outputs designed to connect to station monitoring system The modems also provides a complete remote Monitor Control M C port allowing the status to be remotely monitored and the unit controlled or the configuration changed If Async ESC feature is available standard on P300 IBS and above the modem can provide an asynchronous Engineering Service Channel carried across the satellite link as a...

Страница 10: ...he addition of extra hardware It might appear that the words Feature and Option are used interchangeably In practice however we have attempted to use Options to refer to functions which always require hardware to be fitted whereas we use Features to refer to functions which may be software enabled without extra hardware being fitted For example we refer to both IDR and G 703 Options as these each ...

Страница 11: ... IESS 308 P1348 Emulation 32 64kbps Aux data in place of one both IDR audio ESC PRBS Tester 8 8 Internal Bit Error Rate Tester BERT overhead modes only 8PSK TCM 8 8PSK with E rate Trellis Code Modulation to IESS 310 Extended D I 8 Independent timeslot re ordering on Tx Rx Signalling CAS for E1 RBS for T1 Rx Partial Insert for multi destinational working Timeslot ID maintenance for N 1 to 31 with I...

Страница 12: ...s 8 1PPM internal frequency clock reference with external station clock input 8 CCITT INTELSAT V 35 scramblers for closed network operation with additional two modes for compatibility with FDC and Linkabit proprietary patterns 8 Deferred alarm at user set service limits individual Eb No BER Buffer slip thresholds 8 Frequency locked clock loops ie not phase locked immune to clock hits caused by equ...

Страница 13: ...r multiplying V 35 self synchronising scrambler L A high rate async ESC channel in IBS SMS overhead achieving 2400 Baud with a 64kbps carrier requires IBS SMS feature standard on P300 IBS and above L Async access to the IDR 8kbps synchronous ESC channel requires IDR option standard on P300 IDR and above L Software selectable RS232 RS485 or RS422 interface 8 IBS SMS Feature Satellite Framing in acc...

Страница 14: ...us ESC interface eg 2400 Baud at 64kbps in standard IBS SMS mode any Baud rate for Closed Net Plus ESC Again typically used for distant end M C via the overhead Aux Port provides a front panel selectable RS232 and RS422 interface In IDR Mode it provides synchronous 32 or 64 kbps channel in place of one or both the 32kbps ADPCM ESC audio channels In IBS SMS Minimum Overhead modes it provide a synch...

Страница 15: ...des a more configurable version of Closed Net Plus ESC where the overhead varies from the standard 16 15 6 7 In minimum overhead mode the user sets the required ESC Baud rate and the overhead is scaled to the minimum value to provide the service required For example 2048kbps with 9600 Baud ESC in overhead of 1 or 64kbps data with ESC rates up to 38 4kBaud With respect to the ESC Channels L Full us...

Страница 16: ... at operator set intervals including average worst case Eb No average worst case estimated user BER average worst case estimated uncorrected BER and the buffer fill state The logged performance monitoring allows investigation into customer reports of poor link performance and can provide a useful correlation against weather conditions etc 3 2 FAULT PHILOSOPHY Faults are split into two categories a...

Страница 17: ...e on the front panel of previous products has been moved to the rear panel and is now combined onto the Async ESC connector a D type connector instead of the difficult to obtain 8 pin din audio type connector See the description of the Async ESC connector under the rear panel description which starts on the next page LED Indicators Five LEDs on the front panel provide summary fault information so ...

Страница 18: ...C female which accepts a 1 10MHz signal either a square wave of 1V p p eg a G 703 para 10 synchronising clock or a sinusoid at a power level of 0dBm or greater An alternative Station Clock signal at RS422 interface levels can be applied to the Async ESC connector Either signal can be used by the modem as a reference for the receive output clock the Station Clock does not have to be the same rate a...

Страница 19: ...om a PC or the printing of the units traffic log to a serial printer PC terminal emulator If the Monitor AGC option is fitted it provides I Q and symbol clock outputs to monitor the receive constellation in order to view received signal quality on an oscilloscope When the IDR option IS NOT fitted it provides an RS232 RS422 RS485 asynchronous port for either the high rate Async ESC facility for IBS...

Страница 20: ...nd so could not be incorporated whilst maintaining CE compliance If this style of connector is required then an external adaptor cable must be used If the G 703 option is fitted then in addition to RS422 V 35 RS232 G 703 is also available as a software selectable interface standard T1 1544kbps G 703 is a balanced 1006 signal and is provided on both D type connectors when G 703 is selected from the...

Страница 21: ...NC PCM 32K ADPCM AUX OUT DPLL BLANK PCM FRAME GEN Rx BUFFER Tx PLL Rate Convert DEFRAMER From FEC Demodulator FRAMER INTERLEAVER To FEC Modulator RS DECODER RS ENCODER INTERNAL BER TESTER Tx FIFO DROP MUX Rx CLOCK DE INTERLEAVER Rx PLL AUX AUX ESC ESC STATION CLOCK Tx CLOCK IN Tx CLOCK IN T1000 ASIC INTERNAL 1PPM INTERNAL 1PPM 3P 3P 3P 3P 2P 2P IDR OPT FITTED IN OUT INT CLK P300H P300 Modem Instal...

Страница 22: ...AC 8 I I 8 Q Q DAC Tx PLL SYNTH TURBO SEQ SEQ TURBO VIT TCM VIT TCM 50 MHz SAW BPF ADC DIGITAL DEMOD 10 5dB AMP AMP INPUT MATCH LPF AGC DOWN CONVERT MIX SWITCHED LPF BANK P P Rx PLL SYNTH INTEGRATOR From Interleaver To Deinterleaver DUAL FIR FILTERS P300H P300 Modem Installation and Operating Handbook Page 22 ...

Страница 23: ...d Network Resolution of 1 bps Rate Rate Rate I I Uncoded Rate E E BPSK min 4 8k 7 2k 8 4k 9 6k max 1250k 1875k 2187k 2500k QPSK OQPSK min 9 6k 14 4k 16 8k 19 2k mix 2 5M 3 75M 4 375M 5 0M 8PSK TCM min 19 2k mix 5 0M Closed Net plus ESC As Closed Net above but limits include an overhead of approx 1 4 x ESC Baud rate Resolution of 1 bps ESC from 50Baud to 38 4kBaud IBS SMS Mode 9 6k to 2048k 6 7 ove...

Страница 24: ...turn loss 18 dB typical External reference Clocking only 1kHz 10MHz in 1kHz steps See Station Reference Clocking Frequency 10 MHZ 0 dBm 1 dB Modulator Specifications Output Power Level 0 to 25 dBm continuously variable in 0 1 dB steps from front panel or via remote control Output Level Stability 0 5 dB at 25 C 10 C Transmit Filtering 6th order Butterworth aperture and group delay equalised INTELSA...

Страница 25: ...equalised INTELSAT IESS compliant BER Performance In all cases met in the presence of two adjacent carriers each 10 dB higher than the desired carrier with V 35 scrambling These figures meet or exceed the relevant IESS performance specifications Rate Rate Rate I I Rate E E Viterbi all rates 1 x 10 4 7 dB 6 1 dB 7 1 dB 4 1 x 10 7 2 dB 8 8 dB 9 5 dB 8 Sequential 64kbps 1 x 10 4 3 dB 5 4 dB 6 4 dB 4 ...

Страница 26: ...r disable Transmit input clock plesiochronous includes full asymmetric rate operation Internal reference 1 ppm DCE External timing clock DTE interface only Station reference see below Station References inputs 75 6 BNC female transformer isolated 1MHz to 10MHz in 1kHz steps accepts sinusoid 0dBm or squarewave eg G 703 para 10 1206 RS422 compatible input 1kHz to 10MHz in 1kHz steps When set to 10MH...

Страница 27: ...t of frame sync INTELSAT Reed Solomon Codec Custom Features Format Concatenated Reed Solomon outer codec to IESS 308 310 Code Rate Default n k t 126 112 7 depth 4 automatically switching to 225 205 10 depth 4 for 1544 kbps IDR mode 219 201 9 depth 4 for 2048 kbps IDR mode TCM 1544 kbps and 219 201 9 depth 8 for TCM 1544 kbps Processing Delay Combined Encoder Decoder 8 x 2n k 60 Combined Interleave...

Страница 28: ... 4 5 6 8 10 12 15 16 20 24 30 see Extended D I Feature below Extended Drop Insert Feature Timeslot Re ordering Selected timeslots may be independently re ordered on both Tx and Rx paths Timeslot ID Maintenance The IBS SMS or Closed Net plus ESC overhead is extended to maintain the identity of individual D I timeslots for all values of N from 1 to 31 including the previously unavailable values N 7 ...

Страница 29: ...2nd of the overhead IDR Option IDR ESC Audio Interface Two 32 kbps ADPCM channels 4 wire 600 6 7 dBm to 16 dBm software programmable in 0 1 dB steps Backward Alarms Outputs Four form C relays Inputs Four protected inputs short to 0 V to send alarm with matching summary Rx fail output Alarm inputs software configurable for a all external patch b 1 Rx fail 2 4 External Patch c 1 Rx Fail 2 4 OK d 1 4...

Страница 30: ...rom the main interface This is compatible with a P400 Series modem fitted with P1448 card or a P230 Modem with a P1348 card alternatively Drop Insert can be used at the distant end to place the two 32kbps ADPCM audio channels in one timeslot and the 64 kbps data in another PRBS Tester Feature BER Channel PRBS tester may operate through either main traffic ESC data or AUX data channels main traffic...

Страница 31: ...ers Slew rate limit comms loss action freeze max or nominal power Ancillary features Automatic logging of distant Eb No and local AUPC delta power at user controlled intervals in traffic log Automatically interleaves AUPC messages with distant end remote M C if active on ESC channel Independent Max Min delta powers ie facility to reduce power still maintain quality of service with good atmospheric...

Страница 32: ...maintaining impedances L Band inputs outputs are passively split combined outside the units Offline unit tri states data outputs mutes Tx carrier Mechanical 1 U chassis 355 mm deep Weight 7 lbs 3 kg Power Supply 100 240 Volts AC 10 15 47 63 Hz 25 watts maximum Rated maximum supply current 1A at 100V 0 3A at 240V Fused IEC connector Double pole Neutral fused Fuse rating T3 15AH 250V 3 15A fuse time...

Страница 33: ...onditions FEC Viterbi Rate 128 kbps QPSK TX 140 0000 MHz RX 140 0000 MHz V 35 Scrambling Input Level 60 dBm Spec limit R1 2 Coding Ideal BPSK QPSK Rate 3 4 Rate 7 8 P300H P300 Modem Installation and Operating Handbook Page 33 P300 Modem Series Error Probability versus Eb No Viterbi Decoding ...

Страница 34: ...ns FEC Sequential Rate 64 kbps QPSK TX 140 0000 MHz RX 140 0000 MHz V 35 Scrambling Input Level 40 dBm Spec limit R1 2 Coding Ideal BPSK QPSK Rate 3 4 Rate 7 8 P300H P300 Modem Installation and Operating Handbook Page 34 P300 Modem Series Error Probability versus Eb No Sequential Decoding at 64kbps ...

Страница 35: ... Coding Ideal BPSK QPSK Rate 3 4 Rate 7 8 Test Conditions FEC Sequential Rate 2048kbps QPSK TX 140 0000 MHz RX 140 0000 MHz V 35 Scrambling Input Level 50 dBm P300H P300 Modem Installation and Operating Handbook Page 35 P300 Modem Series Error Probability versus Eb No Sequential Decoding at 2048kbps ...

Страница 36: ...c TCM Rate 2048 kbps 8PSK TX 70 0000 MHz RX 70 0000 MHz V 35 Scrambling Input Level 45 dBm Ideal BPSK QPSK TCM plus RS TCM no RS RS Concatenated Reed Solomon Outer Coding 219 201 P300H P300 Modem Installation and Operating Handbook Page 36 P300 Modem Series Error Probability versus Eb No 8PSK TCM with without Reed Solomon ...

Страница 37: ...P300H P300 Modem Installation and Operating Handbook Page 37 P300 Modem Series Error Probability versus Eb No Turbo Codec ...

Страница 38: ...e products this unit is fitted as standard with an interface that is AN INTEGRAL PART OF THE MODEM main board DO NOT TRY TO REMOVE THE CARD Customer specific interface options are available but these require the standard interface to be snapped off and a connector soldered to the board before the modem can accept other standard Paradise interface cards Note if fitting the additional G 703 options ...

Страница 39: ... again just press the YES Key ie you don t have to reselect the same option to get past the menu just press YES Options displayed with a colon eg 1 Status switch to another screen or subsequent menu but do not affect operation Options displayed with a equals sign eg 1 Off change the configuration and may if changing a relevant parameter affect the traffic Reselecting a current option or pressing Y...

Страница 40: ... unusual settings eg IBS with 7 8 rate FEC If anything is found a warning is displayed and can be masked by pressing YES These are only warnings and after you mask each displayed warning you may continue to operate in that mode if required Use the INFO VIEW CONFIG TX RX COMMON screens to display the summarised configuration Then if need be read the rest of this handbook If that fails when you are ...

Страница 41: ... timeout of remote M C activity expires REMOTE M C Configure Remote Local SEE PAGE 5 SEE PAGE 6 USER OPTIONS Alarm Thresholds Operation Display Analog o p AGC OUTPUT Option Monitor AGC 2 digit numeric entry See handbook appendix E FINAL BER Enter BER threshold below which Deferred alarm is raised DEMOD Eb No Enter Demod Eb No threshold below which Deferred alarm is raised BUFFER SLIP Enter Slip in...

Страница 42: ... summary Inner FEC Reed Solomon summary Aux channel summary Service options summary ESC audio levels Baseband Framed Symbol rates AUPC Remote reporting setting Descrambler summary Buffer size MF slip Partial Insert TS from satellite Baseband mode Data rate Clocking Insert Timeslots VIEW COMMON CONFIG Def d Alm Thesholds BER Eb No Buff slip Actions Buff Auto Centre BER 1E 3 AIS Terr CRC Process E B...

Страница 43: ... CHANNEL Main data path ESC Channel Aux Channel BER PATTERN 2 11 1 2047 2 15 1 2 20 1 INT BER TESTER Option PRBS Tester Off Channel Pattern Results Control BER TESTER RESULTS Display of Sync No Sync Sync loss count Error count Status running stopped reset BER On subsequent screen Sync No Sync Sync loss count Data rate of test Error count Elapsed time BER Key Definitions 1 Error inject 2 Start Rest...

Страница 44: ...uffer multiframe slip Thin route spoof X 50 AIS G 732 Spare bits SATELLITE BER Estimate IBS MF Period Carrier ID s Backward Alarm map 50 75Ohm IF IBS MF Period 4 digit numeric entry ms CARRIER ID S 3 digit numeric entry CARRIER ID s Station ID Carrier ID Spare ID BER ESTIMATE Auto FAW FEC inner Reed Solomon PRBS tester BACK ALARM MAP Normal 64Fr cycle 32 Frame cycle 16 Frame cycle 8 Frame cycle 4 ...

Страница 45: ... async channel Maximum Custom SYNC AUX O H USE ASYNC ESC MODE P230 Compatible Custom All available after Aux RATE DISPLAY Display of rates available with the assigned overhead Max async ESC rate Aux circuit synchronous rate Max oversampled Aux async rate CUSTOM O H ALLOCATION Manual assignment of parts of overhead between ESC and Aux circuits Assignment of TS16 25 of o h when not CAS TS32 bits 5 6...

Страница 46: ...lock RX OUTPUT BEARER CLOCK SOURCE Satellite Tx clock in Internal Station clock Rx Baseband Mode Continuous data Insert mux Rx Bearer Loop Generate STATION CLOCK FREQ Entry of station clock frequency 1kHz to 10MHz 1kHz resolution STATION CLOCK None Via BNC RS422 IF SYNTH REFERENCE Only if Station Clock is specified as 10MHz Normal synths use internal ref Synths use Station Clock AUPC Option AUPC R...

Страница 47: ...ellite Modem Status Display no faults Status Display Tx Rx faults Configuration Summary Traffic Status Summary Rx Status detailed Tx Status detailed Demod status detailed User selection of default screen when Status selected Other status screens by pressing Up or Down from 1st Status screen P300H P300 Modem Installation and Operating Handbook Page 47 6 3 Status SCREEN DISPLAY When Status is select...

Страница 48: ... occurred CARR Mute 1 1 Muted by 1 for 1 logic CARR Mute Ext Muted by external signal on alarms connector CARR Mute RTS Carrier set to RTS controlled and interface RTS line is off CARR Mute Flt Muted due to an internal fault eg synthesiser lock CARR FAULT There is a fault in the carrier on off logic disconnect the carrier from the satellite Demod status Not Locked If the demodulator is unlocked Eb...

Страница 49: ...raffic Status and a Detailed Demodulator Status Any Unit Faults override Tx Rx Traffic Summary and displays the fault message such as When a unit fault is displayed it takes over the whole of the Tx Rx Traffic Summary screen as it is important and likely to relate to both Tx Rx paths The three detailed screens are however still available by pressing the Down key from the Unit Fault Message On each...

Страница 50: ...DEMODULATOR STATUS This screen shows the estimated Eb No This is the composite Eb No including framing overheads as used by INTELSAT when specifying modem performance figures The BER is the final USER BER which is being passed to the customer The Offset is the measured error of the received carrier relative to the nominal position expected which is useful for determining the frequency drift due to...

Страница 51: ...tup to be checked and looks for unusual combinations of configuration parameters eg IBS with rate I FEC coding multiple scramblers selected Check does not prevent operation with any configuration it is simply a convenience for the operator if there are configuration difficulties The Setup Check takes several seconds to run and displays a message when the process is complete MEMORIES STORE RECALL a...

Страница 52: ...lite data to provide whatever ESC rate is selected When this mode is selected there is also the option to provide a Backward Alarm facility Closed Net Plus ESC also has the advantage that at rates above 32kbps a synchronous scrambler is used in place of the error multiplying V 35 scrambler used on normal closed network links and if used with Drop Insert the Timeslot Identity is maintained If you w...

Страница 53: ... compatible with other closed network equipment such as the Paradise P200 and closed network equipment from other vendors PLUS ESC The modem adds the minimum possible overhead to the satellite data down to 1 to support the async ESC rate you set The exact overhead used can be viewed on the Info View Config Tx Rx screens It provides the following facilities A variable rate ESC channel up to approx ...

Страница 54: ...is local equipment if the distant end Rx fails for any reason eg local Tx failure or distant Rx failure The proportion of the overhead assigned to the ESC drops slightly 68 to 65 so the overhead may increase marginally to provide the same async ESC rate NO BACK ALM No Backward Alarm is sent Tx or received Rx and so slightly more of the overhead is available to the async ESC lowering the total over...

Страница 55: ...ar P1348 P1448 voice data mux card used often in SNG applications The menu dialogue for this continues in section 6 6 6 on page 60 6 6 4 Change Tx Rx Baseband CONTINUOUS Menu Selecting CONTINUOUS DATA for the baseband interface leads to the following menu Enter the data rate with any leading zeroes required then press YES if the field is incomplete the unit will add the trailing zeroes to avoid ha...

Страница 56: ... specified The screen above shows groups of eight timeslots selected 1 3 4 5 17 16 15 23 although any combination is possible The selection system works by toggling timeslots or groups of timeslots into or out of the selection In G 732 mode timeslots are labelled 0 31 In T1 D4 and T1 ESF modes timeslots are labelled 1 24 Timeslots already in the selection are toggled out from any position of the s...

Страница 57: ...CAS signalling mode active T1 ESF T1 D4 Timeslots 10000000 Note that in G 732 mode TS0 is never replaced with idle code even if it is part of the Drop selection and Idle is selected If the modem is set for CLOSED NETWORK or standard IDR operation the dialogue finishes here If the modem is set for CUSTOM IDR Low rate format then skip to the T on page 60 If the Extended D I feature is available Stan...

Страница 58: ... in use with the least significant bit of each timeslot being used for signalling in frames 6 12 D4 or 6 12 18 24 ESF of the terrestrial multiframe When this option is selected the Drop Insert data is treated specially and is placed into the bearer by the insert mux in the same frames from which it came It is still possible to drop from and insert into different timeslots it is simply that the fra...

Страница 59: ... RBS are active then the Modem will maintain the timeslot identity by using the satellite TS32 multiframe where possible unless N the number of dropped inserted timeslots falls into the category of Odd values of N It will indicate as follows to which the operator just answers YES to accept the information If no signalling CAS or RBS is active and the value of N of dropped and inserted timeslots fa...

Страница 60: ...dentity of the timeslots will not be maintained as with normal IDR 6 6 6 Change Tx Rx Baseband OTHER Menu If the IDR option is fitted standard on P300 IDR and above then the modem can generate a 64kbps carrier comprising just of two 32kbps ADPCM audio channels or a 128kbps carrier comprising 64kbps data from the main data interface of the modem plus two 32kbps ADPCM audio channels These modes are ...

Страница 61: ... backup clock as used when INTERNAL is selected to maintain the carrier distant demodulator lock and if a framing overhead is active the Backward Alarm Aux and ESC channels INTERNAL The Modem outputs a clock on the Int Tx clock out line see interface card details in appendix A for line names for use by the external equipment Unlike the previous Paradise products there is no requirement to loop thi...

Страница 62: ...ates it does not require the Rx rate to be higher than the Tx or the rates to be in any way related Finally and only for those with inquisitive minds why does it state earlier This option is only of any practical use when the Rx Clocking is set to Satellite or Station Clock Because with Rx Tx Clock In it causes a clock loop as Rx Tx AND Tx Rx with Rx Internal it is the same as selecting Tx Interna...

Страница 63: ...o 100Hz resolution The unit will reject a frequency which falls outside the ranges stated and will prompt the user to re enter the value Once complete the user should press the YES key to accept the new value Mistakes made when entering data can be corrected by using the NO PREV key 6 6 10 Change Tx Rx Modulator MODULATION Menu The modulation may be selected from BPSK Bi Phase Shift Keying QPSK Qu...

Страница 64: ...choices are between NONE uncoded VITERBI if Viterbi FEC option fitted SEQUENTIAL if Sequential FEC option fitted TCM Trellis Code Modulation if the 8PSK TCM feature is available Rate 2 3 only Turbo Turbo Product Code FEC if the Turbo option is available Pressing YES accepts the current FEC type and where there is a choice of FEC rates leads onto the FEC Code Rate selection screen Note that 8PSK an...

Страница 65: ...eturn to the Change Tx Modulator menu This list can contain up to 31 different rates but initially only the following are defined others will be added later Screen Description Exact code rate Delay bits 0 750 Industry de facto 3 4 rate 0 750 4446 0 493 Paradise 1 2 rate 0 492711 4056 0 875 Paradise 7 8 rate 0 875 450 yes 450 0 789 Paradise 3 4 rate 0 789359 6498 Note on processing delay Use the da...

Страница 66: ...r byte are in error However when the error rate exceeds the correctable level unlike other FEC schemes which degrade gracefully Reed Solomon fails dramatically Once the error correction threshold is passed eg 8 errors in our example block the codec considers it uncorrectable and passes the block uncorrected ie the error rate goes from 0 to no error correction in one step There is a small transitio...

Страница 67: ...bi Sequential or No FEC IDR 1544 kbps 225 205 10 2048 kbps Other rates 126 112 7 IBS or All rates Closed Net Note When interworking with NEC modems in TCM mode and IBS framing NEC have chosen to use Interleaving depth 4 for all data rates For rates 1544kbps then it will be necessary to select Other and manually select the interleaving as depth 4 OTHER This option is only available if the Custom Fe...

Страница 68: ...rors degrading performance Other This allows non standard scrambler operation to match the configuration of other non standard equipment which leads onto the following menus Pressing 1 2 3 or 4 toggles each available scrambler between On and Off Scramblers which are not available are shown as N A Not Available as they are out of circuit eg Reed Solomon scrambler when RS is Off This screen specific...

Страница 69: ...controlled by the Sig Valid In the RTS line on a V 35 DCE interface see interface card details in appendix A for line names for other interfaces No alarm is raised when the Tx carrier is muted by the RTS line going to the off state unless the RTS line itself is set to raise an alarm if it goes to the off state Change Terr Intfc Control Lines The operator is warned if the carrier is set to POWER BR...

Страница 70: ...ert option reverses the ordering of the pairs of Tx data symbols from the FEC encoder to the modulator The Normal option is compatible with other manufacturers BPSK equipment The Invert option ie reverse pairs of Tx symbols is compatible with earlier Paradise products such as the P200 which we consider to have the correct symbol pairing On the Rx path the symbol pairing is automatically determined...

Страница 71: ...ull AUPC mode As with MON DIST above it uses the ESC channel to collect Eb No information from the distant modem but in addition it varies the Tx power within the constraints provided to maintain a specified distant Eb No SELF MON This It is ONLY used in Tx only applications typically point to multipoint to attempt to maintain the Eb No at multiple Rx only stations It requires the modem to be able...

Страница 72: ...onditions being considered a bonus It is it not normally necessary to set the minimum delta power to any figure other than zero otherwise any beneficial gain in Eb No caused by good atmospheric conditions will be negated by a decrease in Tx power This facility only exists so if as a condition of being able to use AUPC the satellite operator has asked you to provide a reduced power in particularly ...

Страница 73: ...UPC TOLERANCE Menu This sets a tolerance window on the monitored Eb No The AUPC will only attempt to restore the monitored Eb No to the target Eb No when the monitored Eb No moves outside the tolerance window This It is to prevent the AUPC continuously adjusting the power to compensate for minor normal Eb No variations When the monitored Eb No moves outside the tolerance window the AUPC will attem...

Страница 74: ... or async ESC and allocate different parts of the overhead to each port In Closed Net Plus ESC the ESC channel is already defined to use as much of the overhead as possible and the Aux channel is not available so the Define option is not required and is not offered ASYNC ESC When the ESC port is set for async operation this selection configures the async character format and Baud rate INTERFACES S...

Страница 75: ...tart 8 data bits no stop or parity At 9600 Baud with 8 bits char there are a maximum of 960 async characters per second 9600 10 start 8 bits stop 960 async characters per second requires 9 x 960 sync bits per second to convey unfortunately 8 64kbps above the 8kbps channel capacity and so characters will be lost At 9600 Baud with 9 bits char ie 8 plus parity there are 872 async characters per secon...

Страница 76: ... interface the single Data line used for the oversampled INTELSAT ESC on the Async ESC connector cannot provide a synchronous interface If selected the Aux port operates synchronously and varying amounts of the IBS overhead may be allocated to the sync Aux channel The sync channel may utilise at up to a total of 21 32nds of the overhead which with Standard IBS SMS this allows the Aux port to opera...

Страница 77: ...nu allows the overhead assigned to the ESC port to be determined P230 COMP The standard 20 32nds of the overhead is allocated to the ESC and this is compatible with earlier products such as the P230 P230D I and P1300 P1361 combination The overhead allocated to the ESC is TS16 TS32 bits 5 8 and TS48 TS32 bit 1 is not used as this is reserved for the INTELSAT low rate ESC on the Aux port if so confi...

Страница 78: ...nging the ESC rate overhead ESC assignment which the overhead then adjusts to provide The screens are as follows Each of the XXX fields can display the following uses for that part of the overhead and be toggled between the different uses by pressing the appropriate numbered key The overhead locations are unused ESC Defined for use by the ESC port Aux Defined for use by Aux port CAS In use for Cha...

Страница 79: ... ESC Baud Rate is the maximum continuous rate the ESC channel will support the ESC channel must be set to a standard async Baud rate equal or below this figure using the Async ESC menu selection The Aux Sync Rate is the data rate of the Aux port A DPLL generates this clock however obscure the rate The Aux async Baud is the maximum Baud rate that could be conveyed through this Aux channel if the Au...

Страница 80: ... ESC async character format may be edited by pressing 1 or 2 to select 7 or 8 bits and 3 4 or 5 to select No parity Even parity or Odd parity respectively Note that as described in the last paragraphs shortening the async character reduces the maximum continuous Baud rate as the ESC channel is limited to a finite character rate per second and the more bits in each async character the higher the ef...

Страница 81: ...enu This instructs the Modem make an internal link between the ESC port and the remote M C port It must be set specifically for the end of the link the modem is located at When either of these options are selected the physical ESC port is disabled as it is linked internally to the M C port LOCAL Incoming messages on this modems remote M C port Rx lines from the M C Master device are routed directl...

Страница 82: ...odes for the Audio ESC channels but may also be used when generating a 64kbps IBS carrier comprising of 2 x 32kbps ADPCM audio channels only or a 128kbps comprising of 2 x 32kbps ADPCM audio channels plus 64kbps from the main data port Press 1 or 2 to select which channel then use the Up and Down buttons to vary the level Pressing the up down keys slowly rapidly causes the level to change in 0 1dB...

Страница 83: ...rier we are receiving does not correspond to the destination allocated backward alarm channel 1 The Rx fail signals from the modems receiving the carriers from all the other destinations including this modems Rx fail signal must be externally patched into the corresponding external backward alarm inputs AEEE Alarm 1 is internally connected to the Rx Fail signal alarms 2 4 are available for externa...

Страница 84: ...ependent are Baseband Insert timeslot selection only if Drop Insert active Buff Clk Rx Buffer size clocking mode Demod IF Frequency Sweep control Note that setting Rx Tx even momentarily copies the Rx parameters which track the Tx to the Rx configuration Toggling this option on then off again provides a convenient way to copy the Tx config to the Rx except the IF frequency should this be required ...

Страница 85: ...ally LOOP TERR The PCM bearer at the input to the Drop Mux is looped to the Insert Mux If this bearer should fail no clock or AIS the modem will switch temporarily to Generate Internally so that the Rx traffic is not lost as a result of a Tx fault When set for Loop Terr the Rx Clocking menu asks for the selection of the clock source for the Backup bearer Satellite Internal or Station clock GENERAT...

Страница 86: ...or this destination is selected from the total receive data The incoming data from the satellite is labelled as timeslots 1 N NOTE this labelling bears NO RELATION to the terrestrial timeslots from which the data was dropped at the Tx site It should be read as First through Nth 64 kbps channel of the total sent For example in a 256kbps incoming carrier the Rx data is referred to as TS 1 TS 4 first...

Страница 87: ...k or arbitrary values such as 2500k or 4321k Values down to 1kHz not 1MHz are accepted a frequency of 0 indicates there is no station clock When a Station Clock is present the Modem will use it in preference to its internal frequency reference for clock generation of any backup clocks required See the notes in the Rx Clock section on the following page as to where the modem sources the Rx clock fr...

Страница 88: ...the normal bearer looped from the Drop Mux fails and the unit auto generates a backup bearer onto which to insert the Rx data Note that this screen does not display a Tx option as it is the failure of the Tx bearer input which causes this backup clock to be used in the first place All the options available on any of these menus for the Rx output clock are as follows SATELLITE The clock from the sa...

Страница 89: ... internal reference for backups If the Station Clock is at a different frequency to the Rx Data rate the Rx PLL converts the Station Clock to the correct rate to drive the Rx data towards the terrestrial Should the Station Clock fail then the modem will switch to the internal frequency reference in order to maintain the Rx traffic Again the buffer should be set large enough to accommodate the diff...

Страница 90: ...able under CHANGE USER OPT OPERATION TRANSFER BUFFER MF SLIP A second option is available to automatically force the buffer to its mid position whenever the receive traffic switches from failed to OK This takes advantage of any outage and ensures the buffer is centred every time normal operation begins This option is available under CHANGE USER OPT OPERATION ACTIONS BUFFER AUTO CENTRE This option ...

Страница 91: ... Change Rx Demod IF FREQUENCY Menu See Change Tx Rx Modulator IF Frequency Menu on page 63 6 7 9 Change Rx Demod MODULATION Menu See Change Tx Rx Modulator Modulation Menu on page 63 6 7 10 Change Rx Demod FEC Menu See Change Tx Rx Modulator FEC Menu on page 64 6 7 11 Change Rx Demod REED SOLOMON Menu See Change Tx Rx Modulator RS Menu on page 66 6 7 12 Change Rx Demod SCRAMBLER Menu See Change Tx...

Страница 92: ...ent Please note the following 1 Increased sweep width proportionally increases the carrier acquisition time 2 With low data rates and wide sweep widths ie wider than the recommended carrier spacing it is perfectly feasible to acquire the wrong carrier Typically low rate carriers are clustered together on a transponder and the modem has no way of telling which carrier is which other than it has to ...

Страница 93: ...o re acquire the carrier even with further minor variations in Rx carrier frequency without it sweeping into a false lock If you are attempting to do this when you have the Demod correctly locked you can read the current value of offset frequency from the Demodulator Detailed Status screen in order to adjust the Rx IF frequency 6 7 16 Change Rx ESC AUX BA Menu See Change Tx Rx Modulator ESC Aux BA...

Страница 94: ...e option for each available control signal of ignoring the signal or raising a Traffic Fault alarm if the interface control line goes Off CARD SPECIFIC Some interfaces such as 64 kbps G 703 have specific faults they can monitor in the case of the 64 kbps G 703 interface it is the incoming octet timing or options on the outgoing signal supply outgoing octet timing or not Control over such parameter...

Страница 95: ...e too many contiguous spaces the G 703 receiver fails to recover the clock properly as there are no incoming pulses for a while and it causes data errors HDB3 and B8ZS are both methods of ensuring that no more than three or eight zeroes respectively occur on a G 703 line by substituting strings of more than this number of zeroes with another code in turn this code is detected at the end of the G 7...

Страница 96: ...lines IGNORE ALL All the control lines are ignored the dialogue ends here ACTIVE CONFIGURE The three following screens are presented in turn allowing each line to be individually controlled The line names change to match the interface type selected examples here are for V 35 Note that if the carrier is set to RTS controlled under CHANGE TX MODULATOR CARRIER and the RTS line is set to IGNORE then t...

Страница 97: ...may take local control at any time 6 9 1 Local Control TAKE AWAY GIVE AWAY Selection Under SERVICE FACTORY PARAMETERS REMOTE M C the following menu is provided TAKEAWAY When selected the operator can switch between Local and Remote control at will using the Local Remote options on the Change Rem M C Menu GIVEAWAY When selected a subsequent screen is displayed which allows a timeout of up to 255 se...

Страница 98: ...ntrol is only possible if the protocol is not Off and control has been selected as Remote on the Change Remote M C menu INTERFACE The options available here are RS232 or RS485 RS232 is only usable for a direct connection between a single device and a PC RS485 is required when more than one slave device is connected to the remote M C bus Again see the Remote M C section for complete details of the ...

Страница 99: ...This is the Eb No as displayed on the screen whenever the demodulator status is displayed BUFFER SLIP The operator may also instruct the modem to raise the deferred alarm if the interval between buffer slips is less than a preset threshold The threshold is set in hours and may be for example set to 960 hours 40 days or 1728 72 days to warn if the criteria for clock accuracies for a specific servic...

Страница 100: ... ACTION This option is similar to BER action above except it specifies how the modem is to handle the detection of AIS the Alarm Indication Signal all ones INTELSAT specify the required actions as the Prompt Traffic alarm should be raised AIS should be regenerated to prevent multiple noisy links building up enough errors to stop the all ones being detected and the backward alarm should be sent In ...

Страница 101: ...is returned by the distant equipment when it receives an errored CRC ie the incoming E Bits represent the error rate at the far end of this modems outgoing G 732 link Effectively the error rate on the outgoing link at the far end Default Auto RX INSERT BER The source for the estimate of the BER from the terrestrial port at the input to the insert mux may be selected as described above for the Tx D...

Страница 102: ... output error rate of the RS Decoder based on the number of uncorrectable words passed by the decoder PRBS The real BER as measured by the PRBS tester whether it be in the ESC or Aux channel or the main data channel Default AUTO IBS MF PERIOD This option is only applicable to Custom IBS Minimum overhead modes In this mode the overhead is varied to accommodate any ESC requirements and if the ESC an...

Страница 103: ...rame length at these specific rates Options are Adjust Normal or Don t Adjust Default ADJUST THIN ROUTE SPOOF This interestingly named option is to allow full connectivity of a PCM bearer to be spoofed even if the link is connected over satellite via a thin route ie less than the full PCM bearer using Drop Insert If enabled the following features of the PCM system appear transparent end to end AIS...

Страница 104: ...fault 0 FAULT MODE A value from 0 15 where 0 is Normal Default 0 6 10 9 Change User Opt DISPLAY Menu The options are STATUS SCREEN This selection are covered in the section Status Screen Display on page 47 The options available are Tx RX TRAFFIC SUMMARY or CONFIGURATION SUMMARY Default Tx Rx Traffic Summary UPGRADE MESSAGES The unit will by default display notes on the LCD typically Note when ther...

Страница 105: ... 12 06 97 OK yes 1 Time adjust 2 Date Adjust Change Time Date Menu 6 11 CHANGE TIME DATE MENU This menu is self explanatory and allows the user to set the correct time and date so that events added to the traffic log are correctly time stamped The product is Year 2000 compliant ...

Страница 106: ...n decoder from the FEC unless operating uncoded The difference between this and the To FEC figure shows the improvement due to the Inner FEC BER on FAW An estimate of the USER BER based on the count of errors on the Frame Alignment Words FAW received by the deframer over a 1 minute sliding window Only available if operating in a framed mode This is equivalent to the final user BER The difference b...

Страница 107: ...e carrier and the earth station These were named Station ID Carrier ID Spare ID More recent issues just say reserved for uses such as If the demod is receiving a suitable carrier then the ID s from the received carrier are displayed on this screen These may be manually set at the Tx end of the link by Change User Opt Operation Satellite Carrier ID s 6 12 4 Monitor DISTANT Eb No BER Menu This scree...

Страница 108: ...ectively the lower line shows the target Eb No along with its tolerance window and the current AUPC delta power If the delta power reaches the preset limit either up or down then it is prefixed with either a e or f arrow indicating that the power limit has been reached The down arrow indicates that a subsequent screen shown below shows the limits the AUPC has been constrained to work under Most of...

Страница 109: ...ith contact fax and phone numbers and e mail addresses VIEW CONFIG This screen allows the configuration of the modem to be displayed After selecting between Tx Rx Interface Common and Remote M C subsequent presses of the down arrow display every parameter in that group TERR INTFC This option displays information relating to the terrestrial interface card fitted into the modem The information inclu...

Страница 110: ...he log to be viewed on the LCD The Up Arrow and Down Arrow keys allow the operator to scroll through the list of logged events Each entry is logged with it s time and date PRINT This allows the log entries to be printed to the rear panel serial port on the Async ESC connector either just the unprinted entries or the whole log CLEAR The log is cleared 6 14 1 Log AUTOLOG Menu This first screen sets ...

Страница 111: ...with separate Drop Insert bearers by the use of a twin G 703 terrestrial interface The method of BER measurement can be selected by Change User Opt Operation Terrestrial Rx Insert BER AUPC DELTA POWER This logs the power variation delta power the AUPC has used to maintain the target Eb No See AUPC in section 8 11 1 on page 143 for further details This is useful in case the satellite operator requi...

Страница 112: ...e modem try the cables For the remote loopback to function when this loopback is selected the clocking must be configured in a mode where it would work if the loop were made in the cables Rx clocking must be set to something other than Tx Clock switch to Satellite if this is the normal setting and the Tx clocking must the set to Tx Clock In FEC L The data is looped back after the FEC just before i...

Страница 113: ...so looped RS L The data is looped after the Reed Solomon Encoder interleaver back into the RS Deinterleaver decoder providing a local loop only The Tx data continues to be transmitted and the Rx data from the satellite is ignored ESC Aux channel data which is present in the data stream at the RS codec is also looped From the terrestrial port towards the IF ports the loopbacks in the following orde...

Страница 114: ... RS CORRECTIONS DISABLE This option allows the corrections being made by the RS decoder to be inhibited without the removal of the RS overhead This allows the true effect of the Reed Solomon codec to be seen without data rate changes which would affect Eb No and therefore the error rate 6 15 3 Test PSU S TEMP Menu Power supply monitoring is only available if the Monitor AGC option is fitted If it ...

Страница 115: ... continuously using a 1 minute sliding window When Auto Logging of the BER Tester results is enabled the tester executes a test for the user set BER Auto Log period 1 9999 minutes and records both the average and 1 second worst case BER s in the traffic log of the modem at the end of the period It then automatically re starts a new test for the following period It may operate independently or in c...

Страница 116: ...te is used to determine the overhead added to the main data allowing the minimum possible overhead to be added ie the minimum bandwidth to be used to provide the Async ESC Baud rate required When the ESC channel is used for BER testing the Async ESC is disabled and whatever bandwidth was assigned to the Async ESC channel is used synchronously for BER testing The data rate to the satellite main dat...

Страница 117: ...nly available if the Custom Features feature is available standard on P300 TCM Custom framing is based on either IBS or IDR formats and custom framing provides the following advantages Based on IBS A variable overhead may be added allowing both ESC Aux channels to be scaled to virtually any rate This is achieved by setting the ESC channel to the required Async ESC Baud rate and changing the split ...

Страница 118: ...ile AUTOLOG of PRBS results is active YES is displayed To be able to manually select the BERT mode auto logging of the BER result must be disabled by either setting the Autolog period to zero Main Log Autolog or by clearing the flag requesting it to log the BERT results on the subsequent Autolog screen ONE MINUTE One Minute sliding window mode displays the average BER over the last 1 minute It doe...

Страница 119: ...s to a maximum of 27 7 hours BER The calculated BER over the entire duration of the test ie average over test period It is displayed as follows When there are more than 100 errors the exact BER is displayed When there are less than 100 errors a symbol prefixes the BER display approximately equal to as the result is statistically poor When there have been NO errors the modem does not know if the BE...

Страница 120: ...s dropped to say 4 of the main data channel implying that reducing the bits available to measure the BER by 20 will have no effect on the validity of the BER reading The argument for the Internal BERT is no different 99 9 of the bits available for BER measurement are used with the other 0 1 lost as the processor reads the hardware registers 6 16 SETUP MENU See Setup Initial Configuration Menu on p...

Страница 121: ...ier is therefore 911 from the main menu So the key sequence Main 9 1 1 will kill the Tx carrier whatever screen was left active on the display NOTE This is an OFF only selection to switch the carrier on again you must use the normal sequence Change Tx Mod Carrier On Although 911 is available in both local and remote M C access to the normal carrier on off control is only available under local cont...

Страница 122: ...ernal temperature can be monitored on the TEST PSU TEMP menu A Unit Warning deferred alarm will be activated if ever the internal temperature reaches within 3 degrees Centigrade of the operating limits of 0C and 60C Should the internal temperature exceed the limits of 0C and 60C then a Unit Fault Prompt Alarm is activated The Tx carrier is muted outside the operating temperature range 6 19 2 Servi...

Страница 123: ...ard alarms for Multidestinational IBS Minimum overhead mode where the overhead scales to provide any ESC requirement at any data rate IDR This leads to variants on standard IDR framing again explained later which allow for operation With overheads of 96 64 or only 32 kbps With 16kbps ADPCM on the audio channels instead of 32kbps allowing either all normal IDR features in a 64 kbps overhead or agai...

Страница 124: ...e following screen is displayed If either the Backward Alarm facility or the TS32 Multiframe have been disabled then this menu is skipped NORMAL A single backward alarm operates as normal FOUR ALARMS The modem transmits or receives four independent backward alarms using the form c outputs and backward alarm inputs normally used for IDR operation This allows a single IBS Tx carrier feeding multiple...

Страница 125: ... As the exact overhead format is calculated based on your ESC requirement for two Modems to calculate the same overhead usage and therefore interwork the following parameters must be the same at both ends of the link L Main Data Rate L ESC async character format bits parity Baud rate L Proportion of overhead assigned to ESC L Baseband mode ie continuous or Drop Insert 7 1 3 Change Tx Rx Service Cu...

Страница 126: ...o ESC channels operate in 16kbps ADPCM mode allowing both audio ESC s to fit into 32kbps The 32kbps for FAS Back Alarms 8K sync ESC channel is transmitted first followed by 32kbps defined for Audio ESC 1 now containing both Audio ESCs 1 2 using 16kbps ADPCM These are followed by the 32kbps for Audio ESC channel 2 which is unused and may be defined for use by the Aux port providing either a spare 3...

Страница 127: ...service definitions but the data rate at the terrestrial port is actually 2048kbps When selected instead of the unit inserting extra IBS SMS framing on to the data ie 6 7 it uses the similar G 732 framing already present 0 Some locations in the G 732 framing are changed over satellite such as TS0 Odd bit 4 which is used by the IBS SMS TS32 multiframe word and so it is not entirely transparent to a...

Страница 128: ...s selected a timeslot edit screen is displayed as follows This screen allows the operator to change the order of the transmitted timeslots The screen above shows groups of timeslots 1 15 and 17 31 swopped in location with 1 15 also reversed 15 1 although any combination is possible The selection system works by toggling timeslots or groups of timeslots into or out of the selection Timeslots alread...

Страница 129: ...ALIGN FOR RX A terrestrial G 732 frame format is acquired and is aligned within the IDR frame to allow the receive equipment to re order the timeslots if so set Other than aligning the terrestrial frame within the satellite IDR frame the Tx data is unaffected TX TS RE ORDER This selection leads onto a screen identical to that for IBS G 732 re ordering as described in the last screen shot and parag...

Страница 130: ...than one clock in the system and a buffer is required to absorb the difference between the two clocks Typically data is placed into the buffer with one clock and removed with another thus causing a gradual continuous filling or emptying of the buffer causing slips on a regular basis The period between buffer slips when it is totally full or empty will be constant and proportional to the difference...

Страница 131: ...is enough for the Doppler shift from 1 satellite hop on current INTELSAT satellites For 2 x Doppler shift 4ms is required Set the Tx Rx Clock modes as follows to use the clock listed Clock from the interface terrestrial network Tx Clock Tx Clk In Rx Clock Tx Clk in Modem internal clock Rx Clock Internal and feeds the clock to the terrestrial equipment If the Rx output clock is externally looped by...

Страница 132: ...required for any application If Lc is the local clock accuracy e g 1 x 10 9 and Rc is the remote clock accuracy e g 1 x 10 11 and Ms is the Minimum slip period in days e g 40 days then the required Plesiochronous Buffer size middle to end in seconds is Bs Ms x 24 x 60 x 60 x Lc Rc Simplifying allowing a factor of two end to end buffer not middle to end and allowing 2mS for the Doppler shift gives ...

Страница 133: ... Each of the four sites transmits a 1152kbps 3 x 384kbps carrier and all four destination sites receive the three carriers from the other destinations At each site all three modems are configured for Rx Partial Insert and the data for all but this site is discarded leaving a 384kbps to be inserted onto the looped T1 bearer by each Rx modem In this way the data from each site for this destination c...

Страница 134: ...f t so this intermittent reduction in error correcting capability is minimised Note that in theory error correction codes 100 90 5 and 200 180 10 are equivalent they can correct 5 bytes in 100 and 10 in 200 respectively but the effect of the interleaver synchronisation words will be more noticeable equivalent to a loss of t 1 when t 5 20 loss as opposed to t 10 10 loss On the negative side the lon...

Страница 135: ...126 5 5 and 4 in 64 6 25 respectively with similar overheads 126 112 12 5 64 56 14 3 but with interleaving decoder delays reduced from 5632 to 3104 bits 156ms to 85ms at 32kbps If using Sequential FEC see also Fault Mode 3 in Appendix E 8 5 NOTES ON DATA RATES SYMBOL RATES The normal constraint for a modem is the range of Symbol Rates over which the modem can operate correctly The Symbol Rate rang...

Страница 136: ...n the timeslot ID for an Odd value of N or if RBS signalling is active then only 7 out of 8 of every TS16 are available for ESC as TS16 has to carry the CAS MF unique word or pack byte every 8th frame In this case simply consider TS16 as providing 7 bits of overhead not 8 For Custom IBS modes this is unchanged unless Minimum Overhead mode is selected in which case the overhead will vary up or down...

Страница 137: ...5 1 19 0 62 0 59 19200 Baud n a n a 50 10 5 4 76 2 5 2 38 1 25 1 19 38400 Baud n a n a 100 20 10 5 4 76 2 5 2 38 The formula for deriving the overhead rate is moderately complex and relies on many different parameters For other mixes of data rate and async settings the simplest way to determine the overhead is to enter the parameters into a modem and then select Info View Config Tx A screen such a...

Страница 138: ...hich follows the Custom option from the Tx Rx Service selection screen Main Data Rate Based On TS32 MF Backward Alarm No of Back Alm Overhead Mode 32kbps IBS Normal User choice One Min O H 32kbps IBS No TS 32 MF User choice N A no TS32 MF Min O H In both cases under the ESC DEFINE dialogue set the proportion of the overhead assigned to the async ESC as Maximum all remaining and set the Aux channel...

Страница 139: ...ill be compatible with other manufacturer equipment with the same number of timeslots selected 8 Configure the receive path similarly if Rx Tx is active then only the timeslots need selecting Note the P300 Modem equipped with the Extended D I feature standard on P300 TCM can support any value of N not just N 1 2 3 4 5 6 8 10 12 15 16 20 24 30 as listed for the SDM300 E1_CAS 2048kbps G 732 with Cha...

Страница 140: ...complete 7 If you have selected an Odd value of N the unit will prompt TS Identity over satellite 1 Normal maintain 2 Don t maintain If you select Normal maintain the unit will provide TS identity maintenance for any value of N by using a CAS multiframe If you select Don t Maintain then the Modem will not use a CAS multiframe and will be compatible with the same number of timeslots selected 8 Conf...

Страница 141: ...from the two differing V 35 camps schematic written description was a background pattern dependent error rate in the order of 1 x 10 Note that as the 8 background error rate is pattern dependent there is no guarantee you will see it with regular test equipment such as Fireberds etc which generate repeated fixed patterns In most satellite communications such a background error rate might be masked ...

Страница 142: ... Linkabit Paradise P200 series closed net Scrambler on BPSK requires P300 Tx Spectrum invert Paradise P230 IBS SMS Uses synchronous IBS scrambling so V 35 type not an issue FDC SM290 SM2900 Viterbi V 35 FDC Link FDC SM290 SM2900 Sequential Link FDC V 35 SSE SM3000 4000 Viterbi V 35 FDC 308 SSE SM3000 4000 Sequential 308 FDC V 35 EF SDM 300 300A Viterbi IESS 308 V 35 EF SDM 300 300A Sequential IESS...

Страница 143: ...es through the asynchronous ESC channel which is carried over the satellite multiplexed with the main data channel For AUPC to operate an async ESC channel must be defined and on the P300 this is available in Closed Network Closed Net Plus ESC IBS SMS and IDR modes The AUPC may be set to monitor the distant Eb No Mon Dist shown above or in its normal mode to maintain a distant Eb No Maint Eb No sh...

Страница 144: ...parate upper and lower Tx power limits are set along with a slew rate limit if it is felt that additional limits to prevent rapid power variations are required By manipulating the upper and lower power limits one of three scenarios can be achieved Limits Constant performance Always uses the power required to maintain the Eb No Provided the limits are not reached the link performance will stay as i...

Страница 145: ...feature Change Log Autolog The AUPC delta power can also be output on the uncommitted analog DAC output if the Monitor AGC option is fitted again see uncommitted analog DAC output value 5 in Appendix E starting on page 189 The speed of reaction of the AUPC depends primarily on two factors The user specified slew rate specifically to limit the rate of change of Tx power when a power adjustment is d...

Страница 146: ... reporting rate For Closed Net Plus ESC our suggestion would be to include the optional Backward Alarm as this is a very useful feature and set the Baud rates as high as possible without either exceeding the allotted satellite bandwidth or using an overhead over 10 The ESC channel for the AUPC must have symmetrical Baud rates Set the ESC interface If the ESC channel is to be used for AUPC only set...

Страница 147: ...than the target but will increase the power if the Eb No falls below target To maintain a fixed Eb No set this as the Target Eb No set the Max power to the maximum increase you are allowed and set Min power to the limit of the power decrease you will accept The Tx power will increase and decrease within the limits to try and maintain a constant Eb No Set the Tolerance Window size to something prac...

Страница 148: ...ed in the same bandwidth the resolution bandwidth of the analyser this is the same as E N s o Within the demodulator each Symbol is converted back into the Transmitted Bits For BPSK each Symbol represents only 1 Transmitted Bit for QPSK or OQPSK each Symbol represents 2 Transmitted Bits and for 8PSK each Symbol represents 3 Transmitted Bits The expression E N or E N represents the t o bt o Carrier...

Страница 149: ...dy as it compensates for these parameter changes b o When comparing BER performance for different Modulation FEC schemes against E N the b o plotted E N already accounts for the changes in Carrier Noise caused by the different Modulation b o and FEC settings Any BER difference you see with different schemes is a real difference you don t have to further compensate for the changes in Carrier Noise ...

Страница 150: ... Code rate expressed as n k t 126 112 7 112 Information bits 126 Decoded 219 201 9 201 Information bits 219 Decoded 225 205 10 205 Information bits 225 Decoded 126 112 7 0 51 dB 219 201 9 0 37 dB 225 205 10 0 40 dB i i i Bandwidth change due to framing is ignored in INTELSAT definition of Eb No as Eb refers to the composite data rate o p o p N C o p C N N o p dB 10 Log o p 10 1 10 10 i i i 10 Log ...

Страница 151: ... 6 0 4 74 6 2 5 01 6 4 5 27 6 6 5 53 6 8 5 78 7 0 6 03 7 2 6 28 7 4 6 53 7 6 6 77 7 8 7 01 8 0 7 25 8 2 7 49 8 4 7 72 8 6 7 95 8 8 8 19 9 0 8 42 9 2 8 64 9 4 8 87 9 6 9 10 9 8 9 32 10 0 9 54 10 5 10 09 11 0 10 64 11 5 11 18 12 0 11 72 12 5 12 25 13 0 12 78 13 5 13 30 14 0 13 82 14 5 14 34 15 0 14 86 15 5 15 38 16 0 15 89 16 5 16 40 17 0 16 91 17 5 17 42 18 0 17 93 18 5 18 44 19 0 18 94 19 5 19 45 ...

Страница 152: ...All interfaces also have the facility to disable the outputs either by making the outputs high impedance or by relay switching enabling one of a parallelled pair to drive the outputs without line contention In the event of a catastrophic failure such as a power supply etc the switching circuitry which is distributed between the two units will switch over to the operational unit All interface cards...

Страница 153: ...t its outputs are tri state the standby LED on the front and the Hi Z LED on the rear should illuminate on one modem 5 Connect the data interfaces in parallel and configure the two units alike Suitable adapter cables are available from Paradise for all the standard interfaces 6 Connect the two transmit IF ports to the input ports of a suitable power splitter combiner of the correct impedance 50 6 ...

Страница 154: ...odem as loading the software requires a processor reset and will affect the traffic To access the Boot Menu power the unit up whilst holding in the MAIN key and the following menu will be displayed Option 2 allows the unit to continue as normal Option 1 leads onto the following menu At this point the serial cable supplied with the equipment should be connected between the PC ands the modems Async ...

Страница 155: ...or re boots The first reboot with a new main code the unit performs a checksum test on each bank displaying the results as follows Finally when the checksums are verified the processor jumps into the new Flash code and begins execution of the latest version of the embedded M C code Should the code fail to execute properly hold down the No Prev key to clear the memory Should the program ever crash ...

Страница 156: ... in the field 1 1 OPERATION The standard RS422 V 35 and RS232 interface does not require any resistor packs to be unplugged for 1 1 redundancy operation HOWEVER the G 703 option has a switch to set the mode Normal or 1 1 and the E1 G 703 card a second switch to select 1206 756 operation The Normal 1 1 switch on the G 703 option doubles the impedance so you can connect the two in parallel and also ...

Страница 157: ...he connecting cables extend beyond 10m As an estimate assume the maximum rate halves as the distance doubles ie 5Mbps to 20m 2 5Mbps to 40m etc The input clock data phase is selected automatically reporting a Data Marginal warning whenever it has to switch phase If the modem reports Data Marginal frequently then this is not a modem fault but an indication that you have a clocking problem external ...

Страница 158: ...ate assume the maximum rate halves as the distance doubles ie 5Mbps to 20m 2 5Mbps to 40m etc The input clock data phase is selected automatically reporting a Data Marginal warning whenever it has to switch phase If the modem reports Data Marginal frequently then this is not a modem fault but an indication that you have a clocking problem external to the modem ie changing clock data phase a proble...

Страница 159: ...kbps to 40m etc NOTE this is a synchronous RS232 interface if you need an asynchronous interface please contact the factory The input clock data phase is selected automatically reporting a Data Marginal warning whenever it has to switch phase If the modem reports Data Marginal frequently then this is not a modem fault but an indication that you have a clocking problem external to the modem ie chan...

Страница 160: ...E1 cards AMI or HDB3 In coded ie non AMI modes the modem will display a Data Marginal warning whenever a line code violation is detected For T1 cards a choice of line lengths is also given to allow the card to pre compensate the T1 signal for line losses If you are in doubt select the 133 feet option no pre compensation Switch Link Settings For T1 G 703 cards set SW2 to Position 2 For E1 G 703 car...

Страница 161: ...pedance if power is removed allowing the units 1 1 partner to carry the traffic The normal input impedance switches to whichever one is on line with the standby input at high impedance Installation note If installing the G 703 card the BNC labelled IN connects to J3 on the card and the BNC labelled OUT to J2 on the card ...

Страница 162: ... X 21 unless you set the clocking correctly The Rx Clock Menu is used to set the source of the single clock from the modem as either Satellite Internal or Station Clock Do not select Tx Clk In as this does not exist in X 21 The Tx Clocking should simply be set to Rx as the Tx data is clocked by the same clock as the Rx data The maximum data rate is 10Mbps over good quality twisted pair screened ca...

Страница 163: ...be set to return Rx data in time with the single Tx Clock by also selecting Tx Clock In NO OTHER COMBINATIONS WILL WORK The maximum data rate is 10Mbps over good quality twisted pair screened cable but this rate is reduced as the connecting cables extend beyond 10m As an estimate assume the maximum rate halves as the distance doubles ie 5Mbps to 20m 2 5Mbps to 40m etc The input clock data phase is...

Страница 164: ... allowing software selection of the interface RS422 V 35 RS232 G 703 control lines in non G 703 modes RTS etc in and line code and length in G 703 modes With the appropriate pins grounded the modem recognises it as a Eurocom D or G card and the software selections relating to the other interfaces are not available NOTE ESPECIALLY That when switching between Normal Eurocom D and Eurocom G modes ie ...

Страница 165: ...k Out ST 114 21 8 LK 7 DATA CIRCUIT FROM MODEM RX 8 Clock Out RT 115 4 17 LK 4 8 Data Out RD 104 16 3 LK 5 COMMON LINES 8 Ground to Activate Eurocom D 14 n a Do Not Connect 12 20 n a 8 Signal Ground SG 102 2 7 13 15 22 25 n a 8 Shield Protective ground PG 101 1 n a Links All links settings are Centre tap grounded 1 2 link up with the PCB legend the right way up Centre tap floating 2 3 link down wi...

Страница 166: ...rrectly at this rate Min Req Signal Description centre tap of 25 pin Link to ground transformer A B DATA CIRCUIT TOWARDS MODEM TX 8 Clock Data In 24 11 LK 3 DATA CIRCUIT FROM MODEM RX 8 Clock Data Out 23 10 LK 6 COMMON LINES 8 Ground to Activate Eurocom G at 16kbps 20 n a 8 Ground to Activate Eurocom G at 32kbps 14 AND 20 n a Do Not Connect 12 n a 8 Signal Ground 2 7 13 15 22 25 n a 8 Shield Prote...

Страница 167: ...9 Pin D Female pin compatible with SA bus Pin Signal Name name RS232 Direction Name RS485 SA Bus Paradise 1 Shield Gnd Shield Shield Gnd Shield Gnd 2 SRR 3 Master B to modem SSD RX B 4 Slave B from modem SRD TX B 5 Shield Gnd SG Shield Gnd Shield Gnd 6 Slave A from modem RC TX A Tx data 7 SRS 8 SCS 9 Master A to modem SC RX A Rx data Pins 1 5 are both grounded on the modem ie Shield and Ground are...

Страница 168: ... second hop to a more distant station would be the Local end again local because they are the end of that specific link nearest the M C computer Pin numbers for Async ESC ports in the table above are shown as local end pin remote end pin and the cable must be made accordingly taking into 1 account which end of each M C link the particular ESC connector is For user convenience the P300 P400 can pro...

Страница 169: ...lows Unit 1 Unit 2 Pin 1 Screen Pin 1 circuit ground Pin 2 Pin 3 On Line signal 2 1 Pin 3 Pin 2 On Line signal 1 2 Pin 6 Pin 7 Fail signal 2 1 Pin 7 Pin 6 Fail signal 1 2 Keep this lead as short as practical and ensure it is screened to prevent spurious changeovers by noise induced in these high impedance signal leads Refer to the earlier section on 1 FOR 1 switching for details of 1 FOR 1 operati...

Страница 170: ...cy 14 Not connected 15 Ground To externally inhibit the Transmit carrier either apply a TTL CMOS low signal to pin 7 or short pin 7 to ground for example with an external relay closure All relay contacts rated 30V DC 2A or 125VAC 0 4A The functions are as defined below Prompt Unit A unit fault exists i e an equipment failure Prompt Traffic A Tx or Rx traffic fault exists Deferred alarm One of the ...

Страница 171: ...lation monitor Rx signal quality 14 Rx I channel eye 7 Rx Q channel eye 15 Rx symbol clock 13 Ground RS422 Differential Station Clock Input 4 Station Clock a 11 Station Clock b 13 Ground RX CONSTELLATION MONITOR PORT If the Monitor AGC option is fitted it is possible to view a receive constellation but not the more traditional eye pattern To display the receive constellation on an oscilloscope con...

Страница 172: ...annels both ESC and Aux channels ie high rate async ESC INTELSAT low rate ESC cannot be used simultaneously In IDR Mode this port is not used as when the IDR option is fitted separate ESC and Aux ports on the IDR card replace this shared ESC Aux port Refer to the definitions of the ESC Aux ports on the 50 way IDR ESC Aux Backward Alarm connector on the following few pages SERIAL PORT FOR LOG PRINT...

Страница 173: ... Tx ESC Data in 14 8 8 Tx ESC Data in B n c 32 8 Rx ESC Clock out A Rx ESC Clock out 33 8 Rx ESC Clock out B n c 15 8 8 Rx ESC Data out A Rx ESC Data out 16 8 8 Rx ESC Data out B n c 46 8 Tx ESC Octet out A Tx ESC Octet out 47 8 Tx ESC Octet out B n c 48 8 Rx ESC Octet out A Rx ESC Octet out 49 8 Rx ESC Octet out B n c 17 8 8 Ground Ground 8 indicates lines are optional In Closed Net Plus ESC mode...

Страница 174: ...aux port is not used In IBS modes the Aux port can be set to both INTELSAT using TS32 bit 1 and Sync modes selectable to use any of TS16 TS32 bits 1 5 8 TS48 In both modes a clock is provided and the port can be used synchronously with the clock or asynchronously allowing the async data to be oversampled by the higher rate clock In this oversampled mode as specified by INTELSAT the Baud rate is li...

Страница 175: ...y from the front panel of 7dBm to 16dBm Audio is encoded as 32kbps ADPCM or 16kbps ADPCM in some custom modes The Audio ports may be used in two applications In IBS modes if set to emulate a P1348 P1448 Audio Data mux card the ESC ports provide the equivalent of the two audio ports on the P1348 P1448 ie can transmit 64kbps 2 audio channels or 128kbps 2 audio channels plus 64 kbps data from main da...

Страница 176: ...when connected to 0V The Rx summary fault is an open collector output 0V Fail open collector OK From the front panel the backward alarm inputs BA x can be set as follows E Ext A Auto Rx fail O OK Menu Opt BA 1 BA 2 BA 3 BA 4 Mode 1 EEEE Ext patch Ext patch Ext patch Ext patch Mode 2 AEEE Rx Fail Ext patch Ext patch Ext patch Mode 3 AOOO Rx Fail Good Good Good Mode 4 AAAA Rx Fail Rx Fail Rx Fail Rx...

Страница 177: ...l However as most of the processing is provided by the T1000 ASIC the optional hardware is limited to The Sequential FEC a plug in Xilinx chip or module The Turbo codec a plug in module The Viterbi TCM FEC a plug in chip normally fitted but can be removed for Sequential only operation The G 703 option card T1 or E1 variants The IDR ESC interface audio transformers PCM codecs full ESC Aux interface...

Страница 178: ...lowing hardware and software mechanism Needless to say for any specific feature to be used the equipment needs both the hardware to be fitted and the software to have that feature enabled Hardware The equipment determines what boards and assemblies are fitted when it powers up and generates an internal list of its hardware capabilities This can be displayed see Features Hardware below Software Som...

Страница 179: ...URES STANDARD The letters shown represent the features that are permanently enabled in the equipment Standard features even if not required by the current configuration To determine if any of the features are in fact required for the current configuration see FEATURES IN USE above Pressing down arrow shows two data rates Low Rate and High Rate also controlled by feature codes issued by Paradise Re...

Страница 180: ...the features a Feature Code will be provided to make the features permanent If you are unable to contact Paradise Datacom for some reason use one of the 5 day Feature Tests to give you all the features for 5 days while you contact us Each modem has only 3 Feature Tests of 5 days each but when you enter a valid Feature Code the number of Feature Tests will be reset to 3 again FEATURES TEST These sc...

Страница 181: ...backward alarms H Aux IBS variable rate synchronous Aux channel IDR 32 64kbps in place of one both audio J P1348 emulation Emulation of P1348 P1448 cards popular in SNG applications Includes generation of 64kbps carrier from 2 x 32k ADPCM audio using IDR Audio ESC ports or 128kbps from 2 x Audio 64kbps data PRBS Tester 8 8 K PRBS tester Internal BERT can run through Main ESC and Aux channels in an...

Страница 182: ...a modem configuration after timeout eg to re use it then use the configuration memories to store the current configuration before it times out and is changed and recall it after the features are available again eg if you instigate a feature test or have a feature code upgrade APPENDIX C4 ASYMMETRIC LOOP TIMING All P300 modems have this asymmetric loop timing facility this appendix is not relevant ...

Страница 183: ...acters there are no such constraints on the other characters in the message Electrical Interface Both protocols require a 4 wire plus ground interconnection between equipments Signals are at RS485 levels effectively a tri statable RS422 with Tx Rx data being transmitted as a series of async characters over a differential pair labelled A and B Lines referred to as Tx A and Tx B are outputs and Rx A...

Страница 184: ...64 to request a standard ACK add 80H 128 to 10 10 request an extended ACK to this message Body From 0 to 248 characters resulting in a maximum message length of 255 characters Asterisk An ASCII character if there is a body ie if the length of the body of the message 0 Checksum The Modulo 256 sum of all the characters inclusive from the Address to the end of the Body up to and including the asteris...

Страница 185: ...e Body NAK One character an echo of the instruction sent ACK Where no response is expected ie a write message one character an echo of the instruction sent Where a response is called for ie a query message resulting in a read response the body is as defined for that response ETX As Master to Slave Checksum As Master to Slave Message Categories The remote M C messages break down into the following ...

Страница 186: ...t 23 14 ack Change 1 UnitCfgQry V0 61 to unit 24 1 UnitCfgRd Query The parameters which affect both Tx Rx paths including user alarm thresholds and all user settings etc current config or config memories 1 UnitCfgRd V0 61 from unit 26 UnitCfgQry Config 1 UnitCfgWr V0 61 to unit 25 26 ack Change 1 AUPCQry to unit 44 1 AUPCRd Query Settings related to Auto Uplink Power Control AUPC contains paramete...

Страница 187: ...he internal cards software 6 UnitInfoRd V0 61 from unit 18 UnitInfoQry Status 7 SAFChgWr to unit 51 14 ack Change Enter an unpgrade code there is no direct corresponding read other than V1 76 SAFStat 7 SAFStatQry to unit 50 0 SAFStatRd Query Query the hardware software feature capability V1 49 7 SAFStatRd from unit 58 SAFStatQQry Config V1 49 8 ActionWr V1 18 to unit 43 4 ack Action Front panel ac...

Страница 188: ...essages 11 Ack extended V0 61 from unit 1 Note Instruction codes used for SA bus messages are as specified above 30H SA bus instructions 70 7F are not used Note on First Available column Items marked have been available since the version specified but only in specific builds there are different builds of the code as follows Build Name Filename Marked message available Comments P440 build P440Vxxx ...

Страница 189: ...as follows Prompt Unit Fault Any unit fault or Tx traffic fault ie Tx summary alarm Prompt Traffic Fault Any unit fault or Rx traffic fault ie Rx summary alarm Deferred Fault Function unchanged from normal 2 Tx Carrier On Off indication Software V2 12 This feature provides a form C relay contact to indicate the Tx carrier On Off state It may be used to indicate which one of a 1 1 pair is on line a...

Страница 190: ... right down to 16kbps below which with the minimum 512bits of processing memory the delay increases again above 32ms The data rate used to determine the processing memory size is the receive rate including any framing and Reed Solomon overheads as this is the output rate of the sequential decoder See the separate note in section 8 4 on page 134 regarding minimising the Reed Solomon delay 4 Slow Sw...

Страница 191: ... muted when the corresponding ACU block signal is active It will not however immediately switch the traffic over to the other modem in the 1 for 1 pair ie not switch the traffic to the other antenna as the external Tx inhibit is not considered a fault by the 1 for 1 logic Without Fault Mode set to 10 then it would be possible for the ACU to indicate block muting the Tx carrier because the antenna ...

Страница 192: ...s changed which of the two components is delayed with respect to the other between the earliest of the P400 series modems and ongoing P400 P300 production If you experience difficulty interworking in OQPSK mode between equipments switch on this mode at the transmit end of the link which fails 13 Inmarsat ISDN Backup Software V2 14 This additional feature allows an external equipment to provide an ...

Страница 193: ...it repeatability is relatively poor 4dB but on any one unit it will be consistent and so show trends accurately 1 Rx Eb No Level Scaled at 1V per 2dB with extremes of 0V 0dB and 10V 20dB and a 0 1dB resolution This signal is forced to 0V when the demod is unlocked Note that although the scaling extends from 0 to 20dB the actual output range is limited to the range measurable by the software which ...

Страница 194: ...er Software versions 2 12 Valid only when the AUPC feature is active this provides an output of the local power adjustments in made in order to maintain the distant Eb No Scaling is 0V 25dB 10V 25dB with 0 1dB resolution Practically it limits to between the upper and lower AUPC delta limits set by the operator ie although scaled to 25dB it may practically vary only to 3 1dB if those are the upper ...

Страница 195: ...4kbps transmitted by use of a separate CAS Multiframe sequence in TS16 48 Timeslot ID Maintenance which is the facility to maintain the identity of individual data streams when multiplexed together into one aggregate rate carrier eg two independent 64kbps circuits in one 128kbps carrier Additional Features Paradise products In addition to the basic INTELSAT definition above the P300 Modems provide...

Страница 196: ...attern itself is 2 1 32767 bits long and runs throughout the frame 15 Scrambling is however disabled for TS0 TS32 otherwise the distant end could never find the frame sync then TS32 multiframe sync in order to find out where the scrambler starts Backward Alarm The backward alarm is a single bit of TS32 which is connected to a summary Rx Fail signal from the demodulator deframer If at either end of...

Страница 197: ...bly the idle code from one of the other dropped timeslots If the Timeslot ID is maintained you should consistently get the PRBS back in this same subset or single timeslot Bear in mind that without TS ID maintenance when dropping N timeslots statistically it will still work one time in 8xN when the random timeslot alignment happens to be correct Implementation of Timeslot ID Maintenance The requir...

Страница 198: ...ling channel for TS0 nor TS16 as TS0 is reserved for the Frame Alignment Word and TS16 carries the signalling for the other timeslots Robbed Bit Signalling RBS Robbed bit signalling is a technique used on T1 PCM bearers whereby signalling is conveyed by stealing the signalling bandwidth from the 64kbps timeslot to which it relates Once every 6 frames one bit the least significant bit of the 8 bits...

Страница 199: ...nel Associated Signalling to be transferred across the satellite link between E1 PCM bearers within the IBS satellite overhead The P300 equipped with the Extended D I feature standard on P300 TCM uses the CAS Multiframe definition to support CAS and also to provide Timeslot ID Maintenance for Odd values of N N 7 9 11 13 etc which in turn allows the Modem to also support Robbed Bit Signalling RBS T...

Страница 200: ...32 CAS 8 5 TS 32 CAS 8 TS 32 TS 32 6 TS 32 CAS 8 CAS 24 CAS 24 7 CAS 56 CAS 56 CAS 56 CAS 56 8 TS 32 CAS 32 CAS 8 CAS 16 9 CAS 24 CAS 24 CAS 72 CAS 72 10 TS 32 CAS 8 TS 32 TS 32 11 CAS 88 CAS 88 CAS 88 CAS 88 12 TS 32 CAS 16 CAS 24 CAS 24 13 CAS 104 CAS 104 CAS 104 CAS 104 14 CAS 56 CAS 56 CAS 56 CAS 56 15 TS 32 CAS 8 CAS 24 CAS 24 16 TS 32 CAS 64 CAS 16 CAS 32 17 CAS 136 CAS 136 CAS 136 CAS 136 1...

Страница 201: ...re is trouble with the link in the other direction Additional Features Paradise products Where many IDR carriers exist between sites the Audio ESC on the second and subsequent carriers are not required as the mandatory station to station ESC is met with the first carrier The P300 equipped with the IDR option standard on P300 IDR and above allows 32 or 64kbps access to the bandwidth occupied by the...

Страница 202: ...splayed message For Unit Fault Check UNIT FAULTS section For Warning Check UNIT WARNINGS section For Tx Fault Check TX TRAFFIC FAULTS section For Tx Warn Check TX TRAFFIC WARNINGS section For Rx Fault Check RX TRAFFIC FAULTS section For Rx Warn Check RX TRAFFIC WARNINGS section There are also other screens relating to configuration errors and warnings and screens which are displayed simply for use...

Страница 203: ... unit has muted the Tx IF output U CM CM TF Tx carrier muted to prevent transmitting an incorrect signal An external 10MHz station reference may be used as the synthesizer reference so if the station reference is in use check the it is present and has clean enough phase noise for its intended use Unit Fault Tx carrier generation The power detector on the generated Tx carrier indicates a carrier ge...

Страница 204: ... is used to indicate the terrestrial equipment is functioning properly The line switching off may be user set to cause this fault or be ignored Change Terr Int Control Lines See note 5 Opt Opt Tx Fault line off nothing to send line depends on the interface in use eg RS422 DCE RS V 35 RTS This is a handshake T CM line which is used to indicate the terrestrial equipment has data to send The line swi...

Страница 205: ...aseband is set to use T the Drop mux in G 732 mode or 2048k IBS G 732 0 overhead mode and when set by the user to process CRC s Change User Opt Operation Terrestrial PCM Bearer CRC Process If CRC sync is permanently lost check if a CRC is present on the PCM signal Tx Fault Dropped data is all ones AIS The specific timeslots dropped by the Drop Mux contain all ones AIS This is different to the Tx T...

Страница 206: ...ceive downstream equipment but could be due to the modem Rx output failing Check the modem Rx path indicates OK Check the Rx data output from the modem is connected to the downstream equipment Tx Warn TS16 MF Back alarm at Tx input A Multiframe Backward Alarm is detected at the Tx Input this indicates that equipment downstream D SB SD of the RECEIVE path has failed to find multiframe sync and is r...

Страница 207: ...rsion Change Rx Demod Spect Inv Rx Fault De interleaver sync lost The Demod can lock to the carrier and the inner FEC decoder to the demodulated data However T TA TC SB RF the Reed Solomon De interleaver cannot find sync with the decoded data Check the RS de interleaving depth then the values of n and k use Info View Config Rx On Non Paradise Tx modems check the V 35 scrambler is not enabled in ad...

Страница 208: ...o RBS Rx Fault Final data is all ones AIS The final customer data after demodulation error correction deframing and descrambling is all T TA SB ones This is normally used to indicate an upstream equipment fault such as a lack of input clock at the Tx end it is not a modem fault See note 4 Opt Opt Opt Rx Fault X 50 de stuff sync lost In IBS modes at 48kbps or 56kbps the IBS specification IESS 309 s...

Страница 209: ...x fault In such a circumstance the modem temporarily generates a PCM bearer onto which the Rx data can be inserted to preserve the Rx traffic See notes 6 9 Rx Fault Insert bearer AIS generating See above see notes 6 9 T Rx Fault Ins mux bearer frame sync lost The modem only detects frame sync when the Insert Mux is active Check the bearer type is T specified correctly Change Rx Baseband Insert Thi...

Страница 210: ...ANSMIT path ie from our modem Tx output though the Tx chain through the satellite and then through the whole distant end Rx path or even further downstream has failed and is returning an alarm This may be due to a receive downstream equipment failure this Tx chain failing the satellite itself but also possibly the modem Tx output failing Check the modem Tx path indicates OK Check the Tx IF output ...

Страница 211: ...ription of the dialogue under Change Rx Buff Clk Rx Clock to determine which signal the PLL uses as a backup clock Rx Warn No clk ref source now int The reference specified for the PLL which generates the Rx output clock or backup Rx clock has D failed the modem has switched to using the internal 1PPM reference to keep the clock available Check the clock source specified is present If a station cl...

Страница 212: ...arm Change User Opt Thresholds Eb No This may be used as an advance warning of service degradation Rx Warn Rx BER below user threshold The final Bit Error Rate is worse than the user threshold set for a deferred alarm Change User D Opt Thresholds User BER This may be used as an advance warning of service degradation The source for the BER measurement is user defined Change User Opt Operation Satel...

Страница 213: ... from the Doppler Buffer to the Insert Mux has slipped full or empty This should never occur in operation contact factory Rx Warn DISTANT Eb No below threshold The DISTANT modems Receive Eb No ie this local modems TX CARRIER is worse than the D user threshold set for a deferred alarm Change User Opt Thresholds Distant Eb No This may be used as an advance warning of service degradation This functio...

Страница 214: ...s separate 3 Line code setting For P1431 32 cards check the switch on the card itself For P1440 41 42 cards which are configured from the front panel check with Change Terr Int Electrical then reselect G 703 which is followed by the line code configuration 4 All ones the Alarm Indication Signal AIS is a means of signalling to downstream equipment that the data being sent is notvalid It is advised ...

Страница 215: ...lear the memory by powering up the unit while holding in the NO key but you have to hold the key in until the unit gives its normal three beeps 9 If you wish to use Drop Insert and pass the incoming satellite timing to the downstream network this is only possible by setting the Rx Insert bearer to Generate not Loopthrough Change Rx Baseband Insert dialogue and selecting Rx Clock as Satellite Chang...

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