Subscriber Pulse Metering (SPM) Detection

Transcription

1 Subscriber Pulse Meterig () Detectio Versatile telephoe call-charge ad security fuctios for PBX, Payphoe ad Pair-Gai applicatios - employig CML s family of 12kHz ad 16kHz ICs INNOVATIONS INV/Telecom//1 September 2001 CML s curret family of ICs offers a versatile ad varied meu of features for call-charge meterig applicatios. I additio, the battle agaist payphoe fraud is waged usig the CMX641A s selectable 12/16 khz ASK Geerator, i combiatio with a Detector, to provide dyamic olie security. With simple cotrol ad sigal iterfacig, compact packagig ad low power requiremets, each of these products, idividually, presets the desig egieer with the ideal solutio to all call-charge or recordig applicatio problems. Products o CMX631A Low Voltage Detector o CMX641A Dual /Security Detector/Geerator o Pair Gai Dual Detector Subscriber Pulse Meterig () fuctios are employed by a aalogue telephoe system primarily to eable callcharge recordig ad billig. I order to achieve this, the relevat telephoe equipmet must be able to accurately determie several factors, amogst which is the ability to measure the duratio of the call. CML s IC products have the ability to accurately detect 12kHz or 16kHz call-charge toes to most coutries atioal telephoe level ad frequecy specificatios. () Pair-Gai - To allow the trasmissio of aalogue timigs to be passed over a digital system, the CML devices will provide outputs i a digital format i the Toe Follow mode. The offers a adjustable decode badwidth for global system implemetatio. Payphoe Atifraud - Iterferece with the payphoe or its telephoe lie ca be detected by iterrogatio of the remote uit. The CMX641A offers a toe geerator/detector facility to form the core of such a iterrogatio system. This documet describes the fuctios ad applicatios of three of CML s, Pair-Gai ad Payphoe Atifraud ICs. Wirelie Telecoms

2 Sigle ad Dual Chael lie 1 lie 2 Iput sesitivity via exteral compoets Xtal or Clock Iput Sigle Chael Toe Follow Output CMX631A Sigle iput Toe Follow ad Packet Mode outputs Pi selectable to 12kHz ad 16kHz systems D4, D5 ad P3 packages 800µA at 3.0V requiremet (2.2mA at 5.0V) Packet Mode Output -10 amplitude (e) -15 e max CMX641A - Applicatios Dual iput/dual output Selectable output modes (both chaels): Toe Follow Packet Mode High Impedace 12kHz or 16kHz System Select Dual operatig states: Fixed Badwidth: Cotrolled: (both chaels) Level sesitivity ad system frequecy via serial iterface Fixed: (both chaels) level sesitivity via exteral compoets, system frequecy via pi selectio Ehaced Operatio: Idepedet (per chael) cotrol of: Decode badwidth, Level sesitivity ad System frequecy via serial iterface -20 SIGNAL LEVEL (db): ref = 775mVrms Iput sesitivity via exteral compoets -50 MUST DECODE LEVEL MUST NOT DECODE LEVEL Dual Chael AMPLIFIER GAIN (db) VDD =5.0 (± 0.1) VOLTS; TEMP = -40ºC to 85ºC Xtal or Clock Iput Clock Output MUST NOT DECODE fmi MUST DECODE f max MUST NOT DECODE Output Select Toe Follow / Packet Mode emi frequecy (f) Chael 1 Output Tx Toe Output Chael 2 Output D2 ad P4 packages 1.2mA at 3.0V (2.0mA at 5.0V) 3-Lie Serial Iterface System Select / Tx Toe Select (12kHz or 16kHz) ASK Toe Modulatio Output Eable Eabled / High Z

3 i Pair-Gai lie 1 lie 2 Iput sesitivity via exteral compoets Xtal or Clock Iput Output Eable Eabled / High Z Chael 1 Output Toe Follow Mode Dual iputs Dual outputs i Toe Follow mode Pi selectable to 12kHz ad 16kHz systems Pi selectable decode badwidth rage Output Eable fuctio for multiplexig D4 ad P3 packages 750µA at 3.0V requiremet (1.25mA at 5.0V) 12kHz or 16kHz System Select Decode Badwidth Select Chael 2 Output Decode Badwidth Settigs ±1.5% ±3.0% % of omial toe ±5.0% frequecy ±7.5% Pair-Gai - to distribute multiple voice telephoe chaels over a sigle digital route. CML s fuctio i this scheme is to facilitate the detectio ad digitisatio of each chael s call charge meterig pulses for iclusio i the fial multi-chael pair-gai sigal. Aalogue Lie Iputs Pair-Gai Cocetrator Remote Exchage lie 1 lie 2 lie 3 lie 4 Sigle Digital Route lie 5 lie 6 lies out lie lie + Tx i Pair Gai - a Overview Rx

4 Payphoe Security lie 1 lie 2 Iput sesitivity via exteral compoets Xtal or Clock Iput Clock Output Output Select Toe Follow / Packet Mode Chael 1 Output CMX641A - Security Applicatios Dual iputs/dual outputs Pi selectable output modes (both chaels): Toe Follow Packet Mode High Impedace Iput sesitivity by exteral compoets or via serial iterface Tx Toe Output Chael 2 Output Idepedet cotrol of both detector chaels via serial iterface: Decode badwidths Level sesitivity Chael system (12kHz/16kHz) frequecies ASK modulated trasmit toe 3-Lie Serial Iterface System Select / Tx Toe Select (12kHz or 16kHz) ASK Toe Modulatio Output Eable Eabled / High Z Output Eable fuctio for multiplexig D2 ad P4 packages 1.2mA at 3.0V (2.0mA at 5.0V) Payphoe Fraud is resposible for eormous fiacial losses to telecom operatig compaies worldwide. The CMX641A, with its toe geerator ad detector combiatio, offers a uique reliable method of safeguardig payphoe security. Theoretical Payphoe Security Implemetatio ASK Toe Modulatio Exchage Tx Toe Geerator Telephoe Lie 1 12kHz or 16kHz coded iterrogatio Remote Uit (Payphoe) Toe Detector ( Detector) Coded iterrogatio set to lie via Tx Toe Geerator Remote uit replys to iterrogatio If reply is correct, exchage µc allows call to cotiue If the reply is missig or icorrect (due to broke lie or fraud), the µc will termiate the call µc Detector 2 12kHz or 16kHz coded reply Tx Toe Geerator ASK Toe Modulatio µc System Geerator 3 System stadard sequece Detector CMX641A

5 Geeral CML Fuctios Iput Amplifier... with relevat exteral gai compoets, is used to set the overall level sesitivity of the product to coform to the atioal level specificatio ( Must ad Must-Not Decode sigal levels). Additioally, level parameters o the CMX641A ca be set over the serial data iterface. sigal i toe follow output packet mode output - + INPUT AMP 12kHz/16kHz XTAL/CLOCK OSCILLATOR PERIOD MEASURE POWER SUPPLY OUTPUT MODE OUTPUT ENABLE OUTPUT STAGES BANDPASS FILTER LEVEL DETECTION PERIOD MEASUREMENT OUTPUT STAGES This diagram illustrates a typical CML detector chael. Each product described i this documet has additioal fuctio-specific features OUTPUT Output Stages Two outputs are available: Toe Follow ad Packet Mode. To allow multiplexig i a lie card eviromet, the CMX641A ad outputs are additioally cotrollable to a high impedace (off) level. Toe Follow Mode, havig a short (15ms) respose/derespose time, forms a evelope of the iput toe. Host systems will eed to qualify the received toe; this format ca be employed i Pair Gai ad Security applicatios. The Packet Mode oly respods after 40ms of cotiuous toe (with a similar derespose time), igorig erroeous (shorter bursts) toes. This output supplys the host with a pseudo-qualified idicatio of a detectio. Badpass Filter A costat-gai toe badpass/audio-reject filter which is automatically cetred o the selected system frequecy: 12kHz or 16kHz. Level Detector The sigal level discrimiatio fuctio. Iput sigals which fulfil the system-level requiremets activate the period measuremet circuitry. Period Measuremet A valid toe is recogised whe a correct sequece of timig pulses is received from the level-detector circuitry. Differetial Tip (a) Rig (b) sigal i V SS - amp out + iput amp V BI AS Iput Amp Iput Cofiguratios To cater for all types of istallatio, all CML s products ca be cofigured to either: Differetial or Sigle-Eded iputs. Sigle Eded Tip (a) sigal i - + V BI AS V SS amp out iput amp Iput Amp Frequecy Accuracy ad Stability Must ad Must-Not Decode frequecy accuracy is obtaied ad maitaied by the use of a stable Xtal or clock iput. The CMX641A ca be employed as a Master Oscillator for up to 3 additioal microcircuits. Power Requiremets All three products described here are specified to operate accurately over the voltage rage of 3.0 to 5.5 volts.

6 Product Applicatios The CML Advatage PBX ad PABX Lie-Cards - Pair-Gai Systems - Payphoe Security - Featurephoes - Out-of-Bad Sigallig 12kHz ad 16kHz operatio High accuracy ad stability Low Power 2.7 to 5.5 volt requiremet accommodates lie power operatio CMX641A icludes a 12kHz ad 16kHz toe geerator to offer low speed data facility Itegrated solutio; compares favourably with discrete compoet arragemets Simple or serial cotrol CMX641A ad both offer dual-chael outputs Flexible cofiguratio suits multiple applicatios Product Fuctio Chaels Sesitivity Selectivity Cotrol Output Voltage Rage Packages CMX631A Detector Oe ext comps preset pi select toe follow 2.7 to 5.5 V D4, D5, P3 packet mode CMX641A Detector/ Two ext comps preset/ pi select/ toe follow 2.7 to 5.5 V D2, P4 Security Ge/Detect serial select serial select serial select packet mode Detector Two ext comps logic iputs pi select toe follow 2.7 to 5.5 V D4, P3 (adjustable decode badwidths) YOUR LOCAL CML DISTRIBUTOR More Iformatio Packages CMX631AD4 CMX631AD5 CMX631AP3 CMX641AD2 CMX641AP4 D4 P3-40º to +85ºC 16-pi plastic SOIC 24-pi plastic SSOP 16-pi plastic DIL 24-pi plastic SOIC 24-pi plastic DIL 16-pi plastic SOIC 16-pi plastic DIL Oval Park, Lagford, MALDON, Essex CM9 6WG, Eglad Tel: +44 (0) Fax: +44 (0) sales@cmlmicro.co.uk Cosumer Microcircuits Limited