FORM 2 THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION (See section 10, rule 13) "METHOD AND SYSTEM FOR CONDUCTING CONTACTLESS PAYMENT CARD TRANSACTIONS" MASTERCARD INTERNATIONAL INCORPORATED, an American company of 2000, Purchase Street, Purchase, NY 10577 (US). The following specification particularly describes the invention and the manner in which it is to be performed. WO 2006/019997 PCT/US2005/025119 METHOD AND SYSTEM FOR CONDUCTING CONTACTLESS PAYMENT \ CASD TRANSACTIONS SPECIFICATION 5 CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of United States provisional patent application No. 60/588,270 filed on July 15,2004. This application is also related to United States patent applications S/N , and S/N , S/N , and S/N , co-filed on even date, all of which claim the benefit of the aforementioned 10 patent application No. 60/588,270. All of the aforementioned patent applications are hereby incorporated by reference herein in their entireties BACKGROUND OF THE INVENTION Radio Frequency Identification (RFID) tags are small integrated 15 circuits (ICs) connected to an antenna, which can respond to an interrogating RF signal with simple identifying information, or with more complex signals depending on the size of the IC. RFID technology does not require contact or line of sight for communication. Radio Frequency Identification (RFID) technology is now economically viable and is deployed in more and more commercial and industrial 20 applications. For example, RFID technology is now widely used for tags on items in warehouses, shops, ID or access cards, etc. In addition, RFID technology has been introduced in the payment card industry (e.g., by MasterCard, American Express and Visa) in the form of "contactless" payment or credit cards embedded with RFID tags. These contactless payment cards can be used to make electronic payment transactions 25 via radio communication with an RFID-enabled payment terminal. The contactless payment cards can provide consumers with simple, fast and convenient ways to pay for goods and services, for example, in retail establishments, stores or supermarkets. Several RFID technologies are available for use in contactless payment cards and card readers/terminals. The basic components of a contactless system are 30 the contactless reader (or Proximity Coupling Device (PCD)) and a transponder. The contactless reader is an antenna connected to an electronic circuit. A transponder consists of an inductive antenna and an integrated circuit connected to the ends of this WO 2006/019997 PCT/US2005/025119 antenna. The combination reader-transponder behaves as a transformer. An alternating current passes through a primary coil (reader antenna) that creates an electromagnetic field, which induces a current in the secondary coil (transponder antenna). The transponder converts the electromagnetic field (or RF field) transmitted 5 by the contactless reader (PCD) into a DC voltage by means of a diode rectifier. This DC voltage powers up the transponder's internal circuits. The configuration and tuning of both antennas determines the coupling efficiency from one device to the other. The transponders may be the contactless payment cards. For contactless payment card systems to be economically viable and to 10 gain commercial acceptance, the contactless payment cards must be interoperable at all or most RFID-enabled payment terminals, even when the cards and terminals have technological features that are proprietary to specific card providers/issuers, vendors or terminal manufacturers. Industry-wide interoperability is desirable. Towards this end, industry standards organizations and groups (e.g., International Organization for 15 Standards (ISO) and International Electro Technical Committee (TBQ) have formulated voluntary industry standards for implementation of contactless payment technologies. Three such exemplary standards which have been defined by ISO/TEC are the ISO/EC 10536, ISO/DEC 14443, and ISO/IEC 15693 standards applicable to Close Coupling, Proximity and Vicinity cards, respectively. 20 The ISO/IEC 14443 proximity card standards (ISO 14443) have been used for several contactless card deployments worldwide. The targeted range of operations for ISO 14443 proximity cards is up to 10 cms, although this range varies depending on power requirements, memory size, CPU, and co-processor. The ISO 14443 standards document has four distinct parts: 25 • Part 1: Physical Characteristics, defines the physical dimensions for a Proximity Integrated Circuit Card (PICC). The card is the ID-1 size (85.6 mm x 54.0 mm x .76 mm). This is the same size as a bank credit card. • Part 2: Radio Frequency Power and Signal Interface, defines key technical characteristics of the contactless IC chips, including items such as 30 frequency, data rate, modulation, and bit coding procedures. Two variations are detailed in Part 2, the Type A interface and the Type B interface. Both operate at the same frequency and use the same data rate, but they differ from one another in the areas of modulation and bit coding. WO 2006/019997 PCT/US2005/025119 • Part 3: Initialization and Anticollision. Initialization describes the requirements for proximity coupling device (PCD) (i.e., the reader) and the card to establish communication when the card is brought into the reader's radio frequency (RF) field. Anticollision defines what happens when multiple cards enter the 5 magnetic field at the same time, identifying how the system determines which card to use in the transaction and ensuring that all cards presented are inventoried and processed. • Part 4: Transmission Protocols, defines the data format and data elements that enable communication during a transaction. 10 For a system of contactless payment cards and card readers to be compliant with ISO 14443, they must meet the requirements of at least some of parts of the voluntary standard. In addition to contactless technologies that are standardized under ISO 14443, a number of proprietary contactless interfaces are also used in the industry (e.g., Cubic's GO-Card and Sony's FeliCa card). With existing 15 card technology deployments, interoperability can be an issue. Card readers deployed by vendors in the marketplace should preferably accommodate several different card types. For example, a desirable card reader would support ISO 14443 Type A and Type B cards, ISO 15693 cards and any additional proprietary card types. Interoperability issues can arise even with card deployments that are 20 presumably compliant with a single ISO standard (e.g., ISO 14443). In the ISO 14443 standard, all requirements or specifications related to RF Power and signal interfaces in the contactless card and reader system (i.e. the physical layer in an Open System Interconnection (OSI) model view of the system) are defined using separate standardized tests for cards and for readers. The ISO/TEC 10373 Standard Part 6 (ISO 25 10373-6) deals with test methods, which are specific to contactless integrated circuit card technology (proximity card). Compliance of contactless cards and readers to ISO 14443 is verified using reference devices. According to ISO 10373-6, a set of "reference" cards (i.e., Reference PICC), which represent the characteristics of contactless cards, is used for measuring specification compliance of a contactless 30 reader. (See e.g., FIG. la). For example, the Reference PICC is used to test the magnetic field produced or transmitted by a PCD, and to test the ability of the PCD to power a PICC. Similarly, a "reference" reader (i.e., a Test or Reference PCD), which may represent the characteristics of a typical contactless reader, is used for measuring - 4- WO 2006/019997 PCT/US2005/025119 specification compliance of contactless cards. For example, the Reference PCD is used to test the load modulation that is generated by cards during testing. FIG. lb shows the functional tests conducted on a product reader under ISO 10373-6 for testing the power and data links between cards and readers. 5 While the separate card and reader compliance test procedures under ISO 10373-6 may ensure that deployed product devices individually have characteristics that fall in either the designated specification range for cards or readers, the procedures do not ensure interoperability in the field. Cards and/or readers verified as compliant may be only marginally so (e.g., by having a 10 characteristic value at the end or edge of a designated specification range). This manner of standards compliance can lead to operational failure in the field. For example, a marginally compliant card may be unreadable or difficult to read using a card reader that is also only marginally compliant. Consideration is now being given to ways of enhancing 15 interoperability of electronic payment devices that are used in contactless electronic payment systems. Attention is directed to reducing variations in card and reader properties consistent with commonly accepted Standards. In particular, attention is directed to improving specification compliance procedures to enhance interoperability. 20 SUMMARY OF THE INVENTION In accordance with the present invention, methods and systems are provided for enhancing interoperability of electronic payment devices that are used in contactless electronic payment systems. The electronic payment devices 25 include RFID-embedded cards issued to consumers and proximity coupling devices such as RFID-enabled readers deployed by merchants. The methods and systems involve use of a reference card and a reference reader to establish acceptable specifications for issued cards and deployed readers, respectively. The reference card and reference reader are cross-calibrated to link the operational specifications for the 30 cards and the readers. A suitable selection of overlapping specification ranges or tolerances for proper card and reader functions, then enhances the interoperability of the issued cards with a deployed reader, and also the interoperability of deployed readers with an issued card. WO 2006/019997 PCT/US2005/025119 Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description. 5 BRIEF DESCRIPTION QF THE DRAWINGS FIG. 1 a is a block diagram which schematically illustrates the use of a Reference PICC for testing the properties of a product contactless payment card reader and the use of a Reference PCD for testing the properties of a product contactless payment card, as prescribed by the ISO 10373-6 Standard. 10 FIG. lb is a schematic illustration of a set of functional tests conducted on a product reader under conventional procedures for testing power and data links between cards and readers according to ISO 10373-6. FIG. 2a is a block diagram, which schematically illustrates the step of cross calibrating of a Reference PICC with a Reference PCD in accordance with the 15 principles of the present invention. The cross-calibrated Reference PICC and PCD devices are then used for testing the functional properties and specifications of a product contactless payment card and reader, respectively. FIG. 2b is a schematic illustration of the functional tests conducted on a product reader for testing the power and data links between contactless proximity 20 cards and readers in accordance with the principles of the present invention. FIG. 3 is a graph illustrating a range of behaviors of diverse cards simulated by a reference card and as measured or observed by a reference reader, in accordance with the principles of the present invention. FIG. 4 is a graph illustrating the behavior of a complaint card whose 25 behavior lies in the range of behaviors observed in FIG. 3 in accordance with the principles of the present invention. FIG. 5 is a graph illustrating the behavior of a reference card as measured on a reference reader, relative to the behaviors shown in FIG. 3, in accordance with the principles of the present invention. 30 FIG. 6 is a graph illustrating the behavior of a compliant card of FIG. 4 as measured on a calibrated reference reader, in accordance with the principles of the present invention. WO 2006/019997 PCT/US2005/025119 FIG. 7 is a graph illustrating the overlapping specifications derived form cross calibrated reference devices, in accordance with the principles of the present invention. 5' DETAILED DESCRIPTION OF THE INVENTION The present invention is described in the context of implementations of electronic payment systems in which the contactless payment device specifications are intended to conform to a common industry standard such as the ISO 14443 Standard, which further specifies standardized test methods (i.e., ISO 10373 - 6 Test 10 Methods, Proximity Cards) for verification of the specification of individual contactless payment devices. Recently, assignee MasterCard International Incorporated ("MasterCard") has developed proprietary specifications MasterCard PayPass™ ISO/IEC 14443 Implementation Specification ("PayPass") for implementation of proximity payment card technologies. The PayPass 15 implementation is consistent with the ISO 14443 Standard and provides a convenient example illustrating the principles of the present invention. It will be understood that the selection of the PayPass implementation for purposes of illustration is only exemplary, and that the principles of the present invention can be more generally applied to electronic payment devices and systems that operate under other common 20 industry or proprietary standards. The present invention provides a method and a system for enhancing the interoperability of contactless payment devices (i.e., product cards issued to consumers and product readers deployed by merchants), which may be used to conduct electronic payment transactions in the field. The system and method ensure 25 that individual product cards and readers operate or function in tighter specification ranges than they are permitted to operate under the ISO 14443 standard. The system and method involve cross-calibrating the reference devices (i.e., the Reference PICC and Reference PCD devices) which are used to test specification compliance of individual product readers and cards under the ISO 14443 and ISO 10373-6 standards. 30 (See FIG. 2a). The Reference PCD is used to establish a range of observed functional behaviors or parameters ("nominal card range") of the Reference PICC. Product card readers are required to have functional behaviors or parameters that are within this nominal card range as measured by the Reference PCD. Conversely, a Reference - 7 - WO 2006/019997 PCT/US2005/025119 PICC is used to establish a range of observed functional behaviors or parameters ("nominal reader range") of Reference PCDs. Product readers are required to have functional behaviors or parameters that are within the nominal reader range when reading the reference card. 5 FIG. 2b schematically shows the functional tests conducted under the PayPass implementations according to the present invention. The cross-calibration of the Reference PICC and Reference PCD establishes a relation between the two standard devices, and links the specifications for individual product cards with the specifications for product readers. This avoids 10 interoperability failures that may arise under conventional unconnected or separate testing of card and reader specifications, for example, when the cards and readers lie at the extreme edges of their respective specification ranges that are allowed under the ISO 14443 standard. The system and method (which are both collectively referred to as the 15 "PayPass implementation" herein) are based on a mathematical algorithm which ensures interoperability of product payment devices upon the suitable selection or specification of device parameters. To ensure proper functioning of a product reader (e.g., PCD R) with a product card (e.g., PICC Q, a PayPass - Reference PICC is used to generate a range 20 of behaviors [£2(x), £3(x)] in a function f of variable x. The function f may, for example, be a magnetic field response as a function of distance. This range of behaviors [£2(x), £3(x)] is observed on a PayPass -Reference PCD. See FIG. 3. The PayPass implementation may require or specify that a product card (i.e. PICC C) must display a behavior fc(x) that falls within the range of established 25 card behaviors [f2(x), f3(x)] to be "compliant". The behavior fc(x) is observed on the PayPass-Reference PCD. See FIG. 4. Further, the PayPass implementation may require or specify that a product reader (i.e. PCD R) must function correctly with the PayPass - Reference PICC exhibiting a range of card behaviors [fl(x), f4(x)] as observed on the PayPass – 30 Reference PCD to be "compliant". By requiring or specifying that the range of card behaviors [fl (x), f4 (x)] must include the range of card behaviors [f2(x), f3(x)], i.e. [f2(x),f3(x)]c[fl(x),f4(x)], WO 2006/019997 PCT/US2005/025119 the behavior fc(x) of the particular card (PICC C) under consideration is necessarily within the operating range [fl (x), f4 (x)] of the reader (PCD R). See FIGS. 5 and 6. Accordingly, the product reader PCD R is expected to operate properly with the product card (PICC C). 5 Similarly for ensuring proper functioning of a product card (e.g., PICC C) with a product reader (e.g., PCD R), the PayPass - Reference PCD is used to generate a range of reader behaviors [g2(y), g3(y)] for function g of a variable y as observed on the PayPass - Reference PICC. The PayPass implementation may require or specify that a "compliant" reader PCD R should display a behavior gc(y) 10 that falls within the established range [g2(y), g3(y)], where the behavior gc(y) is measured on the PayPass - Reference PICC. Further, the PayPass implementation may require or specify that a product card (i.e. PICC C) must function correctly with the PayPass - Reference PCD exhibiting a range of reader behaviors [gl(x), g4(x)] as observed on the PayPass - Reference PICC. By requiring or specifying that the range 15 of reader behaviors [gl (x), g4 (x)] should include the range of reader behaviors [g2(x), g3(x)], which is mathematically represented as: [g2(x),g3(x)]c[gl(x),g4(x)], the behavior gc(x) of the particular reader (PCD R) under consideration is necessarily within the operating range [gl (x), g4 (x)] of the card (PICC C). Accordingly, the card 20 (PICC C) is expected to operate properly with the reader (PCD R). As a tangible illustration of the mathematical algorithm described above, it may be useful to consider the example of the power requirements for activating a product PICC card. A PCD reader must provide or transmit a certain amount of power to a PICC to activate the card. Conversely, a product PICC card 25 must work with a certain amount of power received from the PCD reader. In the PayPass implementation, the power PC(d), which is delivered or transmitted by a product PCD reader, is measured as function of distance d on the PayPass - Reference PICC. The value of the power level PC (d) measured on the Pay Pass - Reference PICC is required or specified to fall within a range of power levels Rbcpoww 30 In the cross-calibration procedure, the PayPass - Reference PCD is configured to generate different power levels which vary over a range RRXJOVWT. The power levels generated by the PayPass - Reference PCD are calibrated with respect to WO 2006/019997 PCT/US2005/025119 the PayPass - Reference PICC, i.e., the range RRx,power is a value measured on the PayPass - Reference PICG. In the procedure, the output of a signal generator or power source (e.g. a voltage source) feeding the PayPass - Reference PCD may be increased or decreased until suitable power levels RRX,POWERare reached as observeon 5 the PayPass-Reference PICC. The mathematical requirement Rtx,power c Rrx,power ensures that a product PCD reader will properly power a product PICC card. See FIG. 7. More generally, the algorithm described above in ffi [0026] -[0033] 10 leads to a system and method for ensuring or enhancmg power, data transfer, and other functional interoperabihty of product contactless payment devices. This system and method may, for example, involve: (a) measuring the power provided by a PCD on a Reference PICC, (b) measuring data transmission (e.g., modulation depth, or other 15 signal parameters) on the Reference PICC, (c) testing data reception (e.g., load modulation sensitivity) by a PCD by generating different signals through the Reference PICC. The PayPass - Reference PICC is first calibrated with respect to the Reference PCD to determine the levels and characteristics of the 20 different signals generated by the Reference PICC, and (d) measuring the data transmission by a PICC on the Reference PCD, with the Reference PCD sending "average" value commands to the PICC and with the Reference PCD providing an "average" power level. Both the power level and the command characteristics produced 25 by the Reference PCD are calibrated with respect to the Reference PICC, (e) checking the data reception and power sensitivity of a PICC using the Reference PCD, with the Reference PCD sending commands with modulation characteristics and power levels at the border of the 30 tolerance interval or range Rrx. Again, for setting these extreme values, the Reference PCD is calibrated with respect to the reference PICC. 10 WO 2006/019997 PCTAJS2005/025119 The system and method for enhancing interoperability are utilized, for example, in the practice of the PayPass implementation specification. For completeness of description, exemplary portions of the PayPass implementation specification, which describe the electrical characteristics of the contactless interface 5 (i.e. Radio frequency and Signal interface) between a PICC and PCD, are reproduced in Appendix A. The reproduced portions also include step-by-step procedures for cross-calibrating Reference PICC and PCD devices that are used for characterizing the power and data links between payment devices. It will be understood that the foregoing is only illustrative of the 10 principles of the invention, and that various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention. WO 2006/019997 PCT/US2005/025119 i 2 Radio Frequency Power and Signal Interface This chapter specifies the electrical characteristics of the two types (Type A and Type B) of contactless interface supported by PayPass. The interface includes both power and bi-directional communication between a PICC and a PCD. 2.1 Introduction 27 2.2 RF Power 29 2.2.1 PCD Requirements for Power Transfer PCD to PICC 29 2.2.2 PICC Requirements for Power Transfer PCD to PICC 30 2.2.3 Influence of the PICC on the Operating Field 31 2.2.4 PCD Requirements for the Carrier Frequency fc 31 2.2.5 PICC Requirements for the Carrier Frequency £. 32 2.3 Signal Interface PCD to PICC 33 2.3.1 Introduction 33 2.3.2 PCD Requirements for Modulation PCD to PICC - Type A 33 2.3.3 PICC Requirements for Modulation PCD to PICC - Type A 35 2.3.4 PCD Requirements for Modulation PCD to PICC - Type B 35 2.3.5 PICC Requirements for Modulation PCD to PICC - Type B 37 2.4 Signal Interface PICC to PCD 38 2.4.1 Introduction 38 2.4.2 PICC Requirements for Load Modulation 39 2.4.3 PICC Requirements for Subcarrier Modulation - Type A 40 2.4.4 PICC Requirements for Subcarrier Modulation - Type B 41 2.4.5 PCD Requirements for Modulation PICC to PCD * 42 12 WO 2006/019997 PCT/US2005/025119 2.1 Introduction This chapter specifies the RF Power and Signal Interface requirements for the PCD and PICC. All the requirements included in this chapter are specified in function of the PayPass reference equipment Each requirement is preceded by a measurement procedure describing how to use the PayPass reference equipment to validate the specific requirement The remainder of this section explains the approach for writing the requirements. A device, which can be a PCD or a PICC, is either transmitting or receiving. A PCD transmits power and data to a PICC and receives data from this PICC. A PICC receives power as well as data from a PCD and can transmit data to the PCD. The different configurations for transmitting and receiving for PCD and PICC are illustrated in Table 2.1. Table 2.1—Configurations Transmit and Receive PCD Transmit Receive PICC Transmit Receive Power V. A Data V V V V For each device, the requirements related to transmission are such that the value of a transmission parameter must fall within a well defined range R* for this parameter. The requirements on reception are such that the receiver must properly work with the value of different parameter varying over a range R,* relevant for each parameter. For interoperability, the ranges for corresponding transmission and reception parameters are defined so that the range R« is contained within R„c (sometimes denoted as R« c R„). Whether a device meets the transmission requirements is measured by means of the receiver of the appropriate PayPass reference equipment. E.g. whether the transmitter of a PCD meets the requirements is measured by means of the PayPass - Reference PICC. The quality of the transmitter of a PICC is measured on the PayPass - Reference PCD. Example: A PCD must provide a certain level of power to a PICC. The power delivered by the PCD is measured on the PayPass - Reference PICC. The value of the power level measured on the PayPass - Reference PICC must fall within range Rx,power. Whether a device meets the reception requirements, is measured by having the transmitter of the appropriate PayPass reference equipment create a range of values for a number of parameters. E.g. whether the receiver of a PCD meets the requirements, is measured by having the PayPass -Reference PICC sending out different levels of load modulation. The quality of the receiver of a PICC is verified by having the PayPass - Reference PCD sending out different levels of modulation. In order to calibrate the transmitter of the PayPass reference equipment, me receiver of the matching PayPass reference equipment is used. E.g. the load modulation level of the PayPass-Reference PICC is calibrated with respect to the PayPass - Reference PCD. The modulation level of the PayPass - Reference PCD is calibrated with respect to the PayPass - Reference PICC. 13 WO 2006/019997 PCT/US2005/025119 Example: A PICC must work with a certain power level provided by a PCD, The PqyPass - Reference PCD generates different power levels, varying over a range Rx,power The power level of the PayPass -Reference PCD is calibrated with respect to the PayPass - Reference PICC. This means that Rixj»wer is a value measured on the PayPass - Reference PICC and that the power level of the signal generator feeding the PayPass - Reference PCD is increased/decreased until the correct (voltage) level is reached on the PqyPass - Reference PICC. The power and data transmission characteristics of a PCD can be tested in isolation as the PCD is a master device. Testing the characteristics of a PICC cannot be done in isolation, as a PICC is a slave device, requiring stimulation from a PCD. For testing the transmission characteristics, the PICC will receive commands from the PqyPass - Reference PCD. Signal parameters will have an 'average' value within the range R„ allowed, thus maximizing the probability of a response from the PICC. For both a PCD or a PICC, checking the data reception characteristics depends on some kind of acknowledgement of the device that the data was well received. For a PCD, sending the next command (=data transmission) in the overall flow implies mat the response from the PqyPass -Reference PICC is well understood. For a PICC, a response (= data transmission) implies that the command from the PCD is well understood. For the remainder of the text, the verbiage "function properly" will be used for a PCD sending the next command, following a response created by the PqyPass - Reference PICC. The verbiage "function properly" is also used for a PICC sending a response to a command generated by the PayPass - Reference PCD The approach explained above leads to the following for what concerns power and data transfer: • Power provided by a PCD is measured on the PqyPass - Reference PICC. • Data transmission by a PCD (modulation depth,...) is measured on the PayPass - Reference PICC. • Data reception by a PCD (load modulation sensitivity) is tested by creating different signals through the PayPass - Reference PICC. To determine the levels and characteristics of the signal generated by the PayPass - Reference PICC, the PqyPass - Reference PICC is first calibrated with respect to the PqyPass - Reference PCD. • Data transmission by a PICC is measured on the PqyPass - Reference PCD, with the PayPass - Reference PCD sending 'average' value commands to the PICC and with the PqyPass -Reference PCD providing an 'average' power level. Bom the power level and-the command characteristics produced by the PayPass - Reference PCD are calibrated with respect to the PqyPass - Reference PICC. • Data reception and power sensitivity of a PICC are checked by means of the PqyPass -Reference PCD, with the PqyPass - Reference PCD sending commands with modulation characteristics and power levels at the border of the tolerance interval R«. Again, for setting these extreme values, the PqyPass - Reference PCD is calibrated with respect to the PqyPass -Reference PICC. -14- WO 2006/019997 PCT/US2005/025119 2.2 RF Power This section specifies the requirements for the power transfer from PCD to PICC through the electromagnetic field created by the PCD. 2.2.1 PCD Requirements for Power Transfer PCD to PICC This section specifies the PCD requirement for the power transfer from PCD to PICC. The PCD creates an energizing RF field (the Operating Field) that enables the PICC to power up. Table 22 describes the measurement procedure for the power transfer from PCD to PICC. Table 2.2—Measurement of Power Transfer PCD to PICC (PCD Transmission) Step # Action Step 1 Regulate the PCD in such a way that it emits the carrier without any modulation. Regulation of the PCD is performed by means of the SDK as described in PTAJ. Step 2 Calibrate the PayPass - Reference PICC for power and data reception as specified in annex B.6.1 Step 3 Place the PayPass - Reference PICC in die Operating Volume of the PCD. The modulator input (J2) of the PayPass - Reference PICC must be disconnected. Step 4 Measure the voltage Vov (DC) at J1 of the PayPass - Reference PICC. Requirements 2.1—Power Transfer PCD to PICC (PCD Transmission) PCD 2.2.1.1 Within the Operating Volume, the PCD shall generate a DC voltage Vov at JI of the PayPass -Reference PICC. Refer to Annex A for the value of Vov. 15 WO 2006/019997 PCT/US2005/025119 2.2.2 PICC Requirements for Power Transfer PCD to PICC This section specifies the PICC requirement for the power transfer from PCD to PICC. Table 23 describes the measurement procedure to verify if the PICC functions properly with the PayPass -Reference PCD creating an Operating Field with field strength Hov- Table 2.3—Measurement of Power Transfer PCD to PICC (PICC Reception) Step # Action Step 1 Calibrate the PayPass - Reference PCD for power transmission as specified in annex B.5.1. Step 2 Place the PayPass - Reference PICC in position (i=0,