Patent Publication Number: US-6342844-B1

Title: Two-way radio-based electronic toll collection method and system for highway

Description:
FIELD OF THE INVENTION 
     This invention relates generally to automatic radio-frequency (RF) real-time high-way toll collection from moving vehicles. It especially adapted to the use of an untraceable electronic check debited from smart card and communicated in a cryptographically sealed envelope message. The invention relates directly to an in-vehicle unit (IVN), noncontact IC card (NIC), a roadside collection station (RCS) and to an overall system incorporating a plurality of RCS&#39;s, IVN&#39;s and NIC&#39;s. The invention may be used for parking collections and other types of road pricing applications. 
     In addition this invention may be used for individual access control wherein the remote toll systems enable personal authentication and payment. 
     BACKGROUND OF THE INVENTION 
     An automatic toll-paying systems which utilizes a recording medium, for example an integrated circuit card (IC card), of a prepaid system has been previously developed for paying charges for utilization of pay facilities, for example for paying a toll for passage over a toll road or for a passage over a toll-gate in public transport. In such a prepaid systems, a prepaid amount of money is recorded beforehand on a recording medium, and every time a toll road is utilized, a toll for passage is subtracted from the amount of money recorded on a recording medium through wireless communication at a tollbooth gate at an entrance or an exit, and a balance is recorded on the recording medium. 
     However, in the case of such an automatic toll-paying systems, if a balance recorded on the recording medium is not enough for a necessary amount of money such as a toll for passage it becomes difficult to pay using the recording medium and complicated operations becomes necessary such as a shortage amount must be paid in cash, or this debt has to be stored in the recording medium or in a special accumulator in a vehicle carried device and afterward the debt should be returned to the creditor. 
     In order to solve the mentioned problems there is a few decisions presently utilized in similar operation comprising communication via electromagnetic waves. 
     The first group of an automatic toll-paying systems includes a microwave and cryptographic units arranged on-board of a vehicles. This unit comprising reader/writer block to operate with contact computerized and/or memorized prepaid smart cards. U.S. Patents which reflect the discussing area are hereby incorporated herein by reference: 
     U.S. Pat. No. 5,485,520—Chaum et. al. (1996); 
     U.S. Pat. No. 5,663,548;—Hayashi et. al. (1997) 
     U.S. Pat. No. 5,532,689—Bueno et. al. (1996) 
     U.S. Pat. No. 5,608,417;—de Vall et. al. (1997) 
     U.S. Pat. No. 5,661,286—Shuno et. al. (1997) 
     One or more roadside collection stations (RCS) communicate over a short-range, high speed bi-directional microwave communication link with one or more in-vehicle units (IVU) associated with one or more respectively corresponding vehicles in one or more traffic lanes of a highway (U.S. Pat. No. 5,485,520). At least two up-link (IVU to RCS) communication sessions and at least one downlink (RCS to IVU) communication session are transacted in real time during the limited duration of an RCS communication footprint as the vehicle travels along its lane past a highway toll plaza. Especially efficient data formatting and processing is utilized so as to permit, during this brief interval, computation of the requisite toll amount and a fully verified and cryptographically secured (preferably anonymous) debiting of a smart card containing electronic money. Preferably an untraceable electronic check is communicated in a cryptographically sealed envelope with opener. Transaction linkage data is utilized in each phase of the complete toll payment transaction to facilitate simultaneous multi-lane RCS/IVU operation. A plaza computer local area network and downlink plaza controller is also used to facilitate simultaneous multi-lane transactions. 
     A hand-held portable smart-card reader/writer with radio frequency receiving/transmitting means is disclosed in U.S. Pat. No. 5,532,689 France. Herein is described a method of transmitting data quickly and securely from a smart card during a remote transaction between a fixed station and a mobile item of equipment containing a smart-card reader, said card reader having a fast memory, wherein, on receiving said card, and in addition to storing the data from the card in said fast memory, said reader also stores a pair of data items in said fast memory, one of which data items identifies the number of the card, and the other data item corresponds to an access count indicating the number of accesses to the card, each access by any reader incrementing the access count in the card by unity, and wherein, during the transaction, the mobile item of equipment, which is interrogated remotely by the fixed station, compares said pair of data items stored in said fast memory of said reader with the pair of data items of the card that is currently inserted in the mobile item of equipment, and transmits the result of the comparison and the data of the card, which data is stored in the fast memory, to the fixed station. 
     However a vehicle carried units for automatic toll payment systems are too complicated device as they operate in a microwave mode similar to cellular telephones and pagers. Furthermore the hand-held and/or vehicle carried unit must have IC card reader/writer with appropriate security functions to prevent tampering and/or using of forged (false) IC cards. All these features add an additional value in the cost of a system, and do not make it versatile and convenience to spread these system to the other market applications. Moreover the vehicle carried units can not be used in individual transport applications like in subway gates or in buses due to it cost, complexity and non convenient to use and wherein person uses individual contactless radio frequency IC cards becoming to be versatile. 
     The radio frequency (RF) Smart cards become to be a standard convenience element for transport and access applications. These noncontact IC cards and/or tags for performing proximate data communication between IC card and the terminal by using electromagnetic waves and having at least one inductive coil employees antenna for power transfer and data interchange are illustrated in U.S. Patents reflecting these area are hereby incorporated herein by reference: 
     U.S. Pat. No. 5,444,222—Inoue et. al., 1995; 
     U.S. Pat. No. 5,394,105—Axer et. al., 1995; 
     U.S. Pat. No. 5,440,302—Irmer et. al., 1995; 
     U.S. Pat. No. 5,329,274—Donig et. al., 1994; 
     U.S. Pat. No. 5,418,358—Bruhnke et. al., 1995; 
     U.S. Pat. No. 5,449,894—Bruhnke et. al., 1995; 
     U.S. Pat. No. 5,418,353—Toride et. al., 1995; 
     U.S. Pat. No. 5,426,667—van Zon et. al., 1995; 
     U.S. Pat. No. 5,241,298—Lian et. al., 1993; 
     U.S. Pat. No. 5,317,330—Everet et. al. 1994; 
     U.S. Pat. No. 5,065,137—Herman et. al. 1991. 
     Systems for noncontact exchange of data are known in different designs and types. Inductively operating systems comprising radio frequency tags and reader/writer terminal and performing low frequency range less than one megahertz (MHz) that allows to operate at relatively long distances are well known in the art. Such tags provide the advantage of permitting through-the-body operation and easy clock generation. However these low frequency systems can not provide relatively high rate data exchange, an despite that they may operate at relatively long distances the portable carrier must be attendant in a special recognition area during a significant time to provide identification and data transfer. Furthermore these systems can not provide the adequate protection on security level during short interaction time because of low rate of data exchange. Moreover they operate at constant frequency that allow the interception of a signal and hacking of security. In addition the returning signal from tag to the reader is more than 80 dB less than transmitted signal from the reader to the tag. 
     The embodiment disclosed in U.S. Pat. No. 5,317,330 enables to increase power retransmitted from portable carrier-tag to the reader by means of providing dual resonant antenna which performs parallel resonant at the receive frequency and series resonant at the transmit frequency. The parallel resonant circuit of antenna derives operating power from the signal transmitted by the stationary member. The series resonant circuit transmits the coded information at a second frequency which differs from the first frequency. Two embodiments are disclosed: first where tag transmission is provided with less frequency: divided by two, and second where tag transmission is provided with higher frequency: multiplied by two. However the method of frequency multiplication is not disclosed. Herein the operation is provided at two constant frequencies that allow the interception of a signal and hacking of secure information. The simultaneous operation in the same capture area of a few alike devices is accompanied with signal interference and collisions. 
     The embodiment disclosed in U.S. Pat. No. 5,608,417 comprising a transponder system employs a transponder antenna with a distributed inductance and capacitance that exhibit parallel and series resonant frequencies. Transmissions to the transponder circuit are made at one or more parallel resonant frequencies to maximize the excitation of the transponder circuit, while return signals transmitted back from the transponder are modulated at one or more series resonant frequencies to maximize the signal current. The transponder antenna is implemented as a pair of aligned coils on opposite sides of a thin dielectric substrate, with the coils connected together through the substrate at one point and the substrate thickness not more than about 25 microns to obtain a significant mutual inductance between the coils. The transponder circuit is designed to respond to the fundamental parallel resonant frequency, at which the maximum voltage is generated by transponder winding, but to transmit the information signal back at a series resonant frequency at which the current in the transponder winding is maximized thus maximizing the strength of the returning signal. The transponder winding has both multiple parallel resonant frequencies and multiple series resonant frequencies. Different parallel resonant frequencies may be used for energizing the transponder at the fundamental and writing to the transponder at the harmonic. Similarly different types of information may be returned from the transponder at a different series resonant frequencies. 
     However the embodiment of U.S. Pat. No. 5,608,417 suffers of many mutual couplings because of distributed inductive and capacitive parameters, which activate many sub-resonant effects, signal scatters and distorts and therefore electronic circuit for proper signal detection and modulation becomes to be too complicated and expensive. Furthermore this embodiment may operate exclusively with frequencies derived as multiplying from fundamental frequency of parallel resonance. Consequently the simultaneous operation of a more than one transponder with one reader/writer will bring into communication collisions. The data transmission is provided by continuous wave with constant frequency. Security features of transmitted data may be achieved solely with software design and one may intercept and decipher data interchange. In addition the utilization of described embodiment in high-speed access and transit systems, like toll high-way systems and toll gates, is difficult because of collisions occurring while IC cards are using the same frequency assortment at once. Moreover the automatic toll-paying systems utilize special roadside collection stations mounted on a special towers remote from moving vehicles, therefore the demand arises to enlarge the amplitude of electromagnetic energy transmitted to the transponder in order to provide power of on-card electronic circuit and proper operation on harmonics. And it is known that each harmonic has an amplitude less then dominant in a few times in proportion to a harmonic number. Still the radiation power limits are restricted by international standards like FCC (USA) and EITS (Europe) and thus it is impossible to power similar RF IC card over large distance more than a few feet. 
     The mentioned above systems do not possess a battery of its own and which draw supply energy required for the functioning of the active electronic components of the responder circuit from the electromagnetic interrogation field, by means of which digital information stored in the responder may be detected. Furthermore, the mentioned above systems may provide the possibility of contactless modification of a data stored in the memory of a responder. 
     The non-contact IC cards used in such a systems are considered to be conventional according to dimensions and size, and, in general, a noncontact card has the shape of a portable member and a size generally equal to that of ordinary magnetic cards, and has internal coil antenna formed as a spiral copper foil pattern by etching or the like. 
     The operation of the RF noncontact IC card when a person who possesses the IC card passes, for example, through a special toll gate controlled by terminal, looks like electromagnetic wave serial exchange between the IC card and terminal over selected allowed channel of a communication link. However there are a very narrow windows in permitted radio-band on electromagnetic radiated fields, which are possible to use to power radio-frequency cards. Particularly at frequencies below 13.56 MHz, it is possible, by limiting the distance between the terminal (R/W) and the card (transponder) to derive the energy for the contactless smart card from the radio waves. Notwithstanding the frequency spectrum for a given radio systems is a limited communication resource (band width and consequently the data rate) and several users may be competing for this communication resource, that may guide to the collisions and interference, and of this kind systems can not provide reliable operation when more than one noncontact IC card is located in active area of a terminal. 
     One of the nearest to our invention embodiment is disclosed in U.S. Pat. No. 5,426,667 where the System for the contactless exchange of data between one or more transmitter/receiver devices and a plurality of responders is described. According to the invention, the responder is designed to exchange data via a microwave connection with a transmitter/receiver device operating in the microwave range, and to exchange data via an inductive coupling with an inductively operating transmitter/receiver device. 
     A system for the contactless exchange of data between at least one transmitter/receiver device and a plurality of responders, wherein at least one of the responders is designed to exchange data via a microwave connection with at least one of said at least one transmitter/receiver device operating in the microwave range and to exchange data via an inductive coupling with at least one inductively operating transmitter/ereceiver device, said at least one responder comprising a microwave antenna device, an inductively operating antenna device, and a data carrier, in which data is stored, wherein between the data carrier and the microwave antenna device means are connected for modulating a received microwave signal with data stored in the data carrier and wherein between the data carrier and the inductively operating antenna device means are connected for modulating an inductively received signal with data stored in the data carrier. However this embodiment operates at one constant frequency (low and/or high) and responders may operate entirely sharing the time to prevent collisions and interference. In addition this system is guarded against signal interception and deciphering on a software level solely and one may record easily the communication protocols and temper it. Moreover the frequency spectrum for a given radio system is a limited communication resource and several users may be competing for this communication resource, that may guide to the collisions and interference, and of this kind systems can not provide reliable operation when more than one noncontact IC card is located in active area of a terminal. 
     The goal of present invention is to merge the convenience of a conventional noncontact radio frequency cards with advanced performances of a complicated apparatuses, like present modern an in-vehicle units for automatic toll collection, comprising functions of a reading/writing from IC cards and transmitting payment information to a distant road collection station. Herein the operating distance is increased and the simultaneous stable non-collision and non-interference operation of a several cards is provided. Furthermore the hopping communication channels support the preventing of interception and easy decoding and deciphering of radio-frequency signal with an attempt of a tempering. 
     Another object of the present invention is to shorten the time of passing through the toll gates, because if prepaid balance is not enough to pay, the debt is recorded into the IC card memory and the next card entering into an ATM machine is accompanied with payment of all previous debts. Besides, the eliminating of reader/writer functions from in-vehicle unit prevents a possibility of hacking of in-vehicle unit with a purpose to avoid reader/writer and send a fraud information about money transfer. 
     Next purpose of a preferred embodiment is the utilization of the single versatile noncontact IC card which may, like present modern IC cards do, to store prepaid value, keep the balance and refund debt automatically while the next operation of money charging into card occurs. The same card may be used in many applications with and without the in-vehicle unit like in automatic vehicle identification, parking, in realtime highway toll collection systems, in public transportation for fare collection, and remote authentication. 
     Additional destination of a preferred embodiment is to provide a low cost solution of a system, comparable with that of the modern noncontact IC card which is built using the already created inexpensive production technology of internal spiral coil antenna for conventional economical and standard RF Cards. Using the same technology the printing of a conductive strip antenna do not add a significant price. 
     The other target of a preferred embodiment is to obtain a low cost of in-vehicle unit due to canceling it&#39;s additional functions as participation in data transmission, reading/writing from/to the card and balance calculation, and elimination of all gadget displays. 
     Additional object of the present invention is to obtain the non-contact IC card of a conventional size and, in general, a noncontact card must have the shape of a portable member and a size generally equal to that of ordinary magnetic cards having internal coil antenna formed as a spiral copper foil pattern by etching or the like. 
     SUMMARY OF THE INVENTION 
     1. In view of the described above problems and goals, an object of a present invention is to provide a two-way radio-based electronic toll collection method to be implemented on highway comprising the steps of providing communication terminal (Reader/Writer) with RF antenna which transmits continuously downlink energy-transmitting signal of first predetermined frequency, and generates a communication hopping channels for bi-directional data transfer, moreover hopping frequency is synthesized of said first predetermined frequency used as reference. Next phase of said toll collection method is to furnish the each vehicle passing along the highway with a noncontact IC card capable to receive said downlink energy-transmitting signal of first predetermined frequency in order to power the electronic components integrated within IC card, which provide the synthesizing of a communication channels of hopping frequency, synchronized by the said first radio-frequency used as reference, and wherein a noncontact card scrolls, detects and selects the available communication hopping channels to establish bi-directional data transfer. In additional the method comprises the installing of in-vehicle unit in each vehicle passing along the highway to receive the said downlink energy-transmitting signal of first predetermined frequency and to verify the field strength of said energy-transmitting signal in order to enable regeneration by in-vehicle unit of an extra portion of energy-transmitting alternating field at the second predetermined frequency with a purpose to feed a noncontact IC card and provide a regular IC card operation. In this method the exchanging of a toll collection and payment information wirelessly between said communication terminal and said noncontact IC card via said bi-directional communication hopping channels start after the one of the channels of available plurality is selected. Said method permits multiple users to communicate over said bi-directional communication hopping channels preventing collisions, interference, interception and easy deciphering of toll collection and payment information. 
     Additional object of a present invention is to provide a noncontact IC card, a terminal for use with noncontact IC card and an in-vehicle carried unit which can radiate additional portion of electromagnetic energy over inductive coupling to power noncontact IC card and a noncontact IC card system having a roadside terminal for use with noncontact IC card and an in-vehicle carried unit and noncontact IC card, wherein the road terminal radiates first radio-frequency of an energy-transmitting signal to power said IC card, and wherein first radio-frequency is used by the IC card as a reference clock to synthesize higher band frequencies to provide a sequence of communication channels using channel hopping in order to realize bi-directional data communication, and wherein card antenna circuit provides parallel resonant to derive operating power from the energy-transmitting signal transmitted by the road terminal (stationary member), and wherein card antenna circuit provides series resonant to transmit and receive data, and wherein in-vehicle unit provides supplementary (extra) portion of electromagnetic radiation to power IC card when IC card located distantly from terminal. 
     Herein in preferred embodiment the parallel resonant circuit antenna presents a high impedance resulting in a large voltage with a small current flow, meanwhile the series resonant circuit antenna presents a low impedance which results in a large current with a small applied voltage. The series resonance minimize the effect of the high frequency transmitted/received signal on the low frequency power signal, enabling simultaneous energy receive and data transmit/receive operation through the same physical antenna circuit. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 a  and FIG. 1 b  are a block diagrams of a two-way radio-based electronic toll collection system comprising a noncontact IC card and a roadside communication terminal for use with noncontact IC card and an in-vehicle carried unit. 
     FIG. 2 a  is a block diagram of noncontact IC card in accordance with first embodiment of present invention. 
     FIG. 2 b  is a block diagram of noncontact IC card in accordance with second embodiment of present invention. 
     FIG. 3 is simplified block diagram of PLL frequency synthesizer of FIG.  1 . 
     FIG. 4 is simplified block diagram of a communication terminal—a roadside collection station RCS combining function of a reader/writer device for noncontact IC card. 
     FIG. 5 is a block diagram of in-vehicle unit. 
     FIG. 6 is an exterior (perspective) view of a first embodiment of noncontact IC card, showing two an etched coil antennas as for power and data communication and arranged on card the integrated circuit IC module, comprising electronic circuit according FIG.  1 . 
     FIG. 7 is an exterior view of a second embodiment of noncontact IC card showing an etched coil antenna for power input and conductive stripe (microwave) antenna for data communication, and arranged on card the integrated circuit IC module according FIG.  1 . 
     FIG. 8 a  is a perspective view of vehicles and a roadside collection station RCS on a highway, FIG. 8 b  depicts a view of vehicle at a parking gate, and FIG. 8 c  represents a view of gate facility with people to which the noncontact IC card system according to exemplary of invention is applied. 
     FIG. 9 a,  FIG. 9 b  and FIG. 9 c  illustrate a method of a system operation in accordance with an embodiments of the invention. 
    
    
     DESCRIPTION OF THE INVENTION 
     FIG. 1 a  exhibits a superposition of blocks in a two-way radio-based electronic toll collection system according to a first embodiment of invention which comprising: a noncontact IC card  1  having power antenna coil  2  in parallel alignment with capacitor  3  and data antenna coil  4  connected in series with parallel combination of coil  2  and capacitor  3 . FIG. 1 b  presents a superposition of blocks in a two-way radio-based electronic toll collection system according to a second embodiment of invention wherein a second example of a noncontact IC card is realized; herein data antenna  4  comprises a conductive strip  5  having a resonant state with parameters of a strip&#39;s equivalent impedance (inductance) in series alignment with distributed capacitance  6  which is combined between said conductive strip  5  and inner line-turn of a said coil antenna  2 . FIG. 7 shows this distributed capacitance  6  as well. The roadside communication terminal  7 , comprising power antenna coil  8  and data antenna  9 , respectively associated with roadside collection station, is arranged in either communication tower  43  or in communication stand  44  (as depicted on FIG. 8 a  and FIG. 8 b ). According to exemplary of invention depicted in FIG. 8 c  the roadside communication terminal  7  is arranged in a gate facility  45 . In this FIG. G 1  represents gates, respectively. Denotes by numeral  46  is a user of a gate facility, who possesses a noncontact IC card. 
     An in-vehicle unit  10  having a coil antenna  11  is designed to supply with additional portion of an energy-transmitting alternating field the noncontact IC card  1  in order to provide a regular IC card operation in the case when a roadside communication terminal  7  is arranged so far from a moving vehicle (FIG. 8 a ). In the event when a roadside communication terminal  7  is arranged proximate near of a vehicle (FIG. 8 b ), the in-vehicle unit  10  do not supply the card with additional energy. Respectively the frequency of an energy-transmitting alternated field radiated by roadside communication terminal  7  is in coincidence with a parallel resonance of a on-card antenna circuit in applications when terminal is in near proximity to noncontact IC card, and in applications wherein a communication terminal is located distantly from a noncontact IC card the roadside communication terminal  7  radiates a substitute frequency for in-vehicle unit  10  to let him recognize that vehicle reached the capture area to provide toll operations. 
     FIG. 2 a  shows the basic block diagram of a first embodiment of noncontact IC card  1 , comprising power antenna coil  2  in a parallel alignment with capacitor  3 , data antenna coil  4  connected in series with parallel combination of coil  2  and capacitor  3 . FIG. 6 depicts a schematic plan view of a spiral coil according first embodiment wherein the coil may be etched, wound, embedded, printed or produced in any other process known in the art. Herein the coil antenna is separated electrically (mechanically it is continual wire) to two parts: coil  2  having more turns for operation in parallel resonant mode and designed to receive the energy-transmitting alternating field (power supply) and coil  4  having less turns for operating in series resonant mode to provide the data communication. FIG. 6 shows the arranged on the card an integrated circuit IC module  12 , comprising electronic components according FIGS. 2 a  and  2   b.  An antenna coil  2  according FIG. 7 is designed solely for receiving the energy-transmitting alternating field (power supply). The production process of it is similar to the coil of FIG.  6 . The conductive strip  5  (see FIG. 1 b  and FIG. 7) in combination with a distributed capacitance  6  is designated to combine microwave antenna for data transmission/receiving and employee series resonant circuit. The functional block diagram of embodiment according FIG. 1 b  and FIG. 7 is depicted on FIG. 2 b  and it differs from FIG. 2 a  in replacing of spiral coil  4  to conductive strip  5  in series alignment with distributed capacitor  6 . 
     In reference to the FIG. 6 the inductance of a coil  4  is designed to be much smaller than inductance of a coil  2 , therefore a parallel resonant circuit, created by antenna coil  2  and capacitor  3  (see FIG. 2 a ), occurs on a lowest frequency than a series resonant frequency of a circuit combined by serial alignment with antenna coil  4  and capacitor  3 . Accordingly, at the lowest operating frequency f 1 , which is designed for power transfer into the card, the antenna coil  4  exhibit a low impedance conductive element and does not effect on a parallel resonant circuit operation and does not cause on a flowing current. In contrast, at the higher operating frequency f 2 , which is designed for data transmission, the antenna coil  2  impedance becomes to be significantly large and do not effect considerably on series resonant circuit operation. 
     Second embodiment of a noncontact IC card  1  (see FIG. 7) is different from a first embodiment in design of an antenna circuit for data communication which comprises a conductive strip  5  having a resonant condition as of strip&#39;s equivalent impedance (inductance) in series alignment with distributed capacitance  6  which is combined between said conductive strip  5  and inner line-turn of a said coil  2  of antenna. 
     The parallel resonant circuit combined by coil  2  and capacitor  3  presents a high impedance resulting in a large voltage with a small current flow accordingly deriving operating power from a signal transmitted by roadside terminal  7  or retransmitted by in-vehicle unit  10 . The series resonant circuit formed by the parallel combination of coil  2  and capacitor  3  in serial alignment with coil  4  presents a low impedance, which results in a large current having a small applied voltage at the data transmit/receive frequency f 2  thus enabling to enlarge the distance of a backward transmission to a terminal  7 . 
     Furthermore the noncontact IC card  1  comprises a microprocessor  13  with memory to store data and programs, a reset circuit  14 , a rectifier circuit  15  to rectify alternating voltage generated by antenna coil  2  at frequency f 1 . Moreover the noncontact IC card  1  includes clock conditioner  16 , frequency synthesizer  17 , transceiver  18  connected to radio-frequency (referred afterward as RF) antenna which may be, as mentioned above, either coil  4  or strip  5 . In addition the noncontact IC card  1  comprises a first frequency multiplier  19  which output is connected with input of demodulator  20  which predetermined to demodulate the data transmitted from roadside terminal  7  and to input this data signal into microprocessor  13 . The output of demodulator  20  is connected to the first input ( referred as Rx) of said microprocessor  13 . The series arrangement of modulator  21  and frequency multiplier  22  is connected to the first output (referred as Tx) of microprocessor  13  and predestined for modulation of outputted carrier radio-frequency with a data signal produced by microprocessor  13 . Clock conditioner  16  serves to supply the regular work of microprocessor  13  (input  2  referred as Clock) with synchronized pulse signal, and to provide a frequency synthesizer  17  with a stable frequency reference which is synchronized by road communication terminal  7  as a carrier frequency of an energy-transmitting signal. Alternating voltage generated by antenna coil  2  at frequency f 1  is applied to a clock conditioner  6  which produces a shaped signal of the same frequency. Reset circuit  14  connected with a rectifier circuit  15  provides reset signal to microprocessor  13  (input  3  referred as Reset) when supply voltage arise and thereafter the microprocessor  13  starts it&#39;s normal operation. All card electronic components are fed with a power supply voltage produced by a rectifier circuit  15 . 
     Frequency synthesizer  17  along with first and second frequency multipliers  19  and  22  in alliance with demodulator  20  and modulator  21  are predetermined to provide a noncontact IC card  1  with a performance of spread-spectrum communication technique. This technique is well known in the art and in general may be realized like Direct Sequence Spread Spectrum (DSSS) or Frequency-Hopping Spread Spectrum (FHSS) as referred in Wireless Informational Networks/ Kaveh Pahlavan, Allen H. Levesque, 1995, John Willey&amp;Sons, Inc., ISBN 0-471-10607-0. Hereafter we shall explain the preferred embodiment taking a frequency-hopping spread spectrum technique (FHSS) as an example of application. Herein the carrier frequency of the digitally modulated data is hopped over a wide range of frequencies prescribed by a periodic pseudo-random (PN) code. In the preferred embodiment the prescribed code is synchronized by microprocessor of a roadside communication terminal  7  and therefore the hopping patterns are selected so that two users of a noncontact IC card never hop to the same frequency at the same time, and thus the multiple-user interference, collisions and interceptions are eliminated. The number of users is limited by the number of frequency slots. The type of modulation of carrier hopping frequency may be similar to any one of the utilized in the art, for example: frequency shift keying (FSK), phase shift keying (PSK), quadrature phase shift keying (QPSK), pulse amplitude modulation (PAM), and in general there is no special restriction to the form of signal modulation. In the disclosed embodiment modulators  21  (on card) and  34  (on terminal) and demodulators  20  (on card) and  32  (on terminal) employee one of the known modulations in the art and for that reason we do not discuss herein in details this process. 
     It is well known that at frequencies below 13.56 MHz it is possible to by limiting the distance between the terminal (Reader/Writer) and the card (transponder) to derive the energy for the contactless smart card from the radio waves. In disclosed embodiment the radiation of an energy-transmitting signal is provided at the low frequency having very narrow spectrum width in order to satisfy the restriction of appropriate Normative Documents (like FCC in USA), preferably this signal has to obtain a continuous sinus wave shape. Said energy-transmitting signal employee as a reference to synthesize at a higher band the communication channels with hopping frequencies in order to supply a several users with this communication resource at one time. As an example of design, the energy-transmitting signal has a frequency of 13.56 MHz and communication channels are arranged in first embodiment within 26.96-27.28 MHz, comprising a band width of 320 KHz, and in second embodiment within of any microwave bands having appropriate frequencies. Therefore the competing for a communication resource will be canceled along with avoiding the collisions, interceptions and interference. 
     PLL frequency synthesizer is depicted at FIG.  3  and comprising channel PROM (programmable read only memory)  23 , first programmable divider  24 , second programmable divider  25 , phase detector  26  in series alignment with lop filter  27 , and voltage controlled oscillator VCO  28 . First programmable divider  24  has a divide ratio 1/R, where R is defined by appropriate command of a channel PROM  23 , which first output is connected with to first input of said divider  24 . Second programmable divider  25  has a divide ratio 1/N where N is defined by appropriate command of a channel PROM  23 , which second output is connected with to first input of said divider  25 . First programmable divider  24  serves as reference divider to produce desired spacing frequency fref for frequency channels, and second programmable divider  25  is predestined to obtain a desirable frequency of VCO  28  as a carrier frequency for communication channels. The phase detector  26  detects the difference between the two frequencies outputted from dividers  23  and  24  in terms of the phase, and produces so-called error voltage and loop filter  27  integrates this phase difference to produce an output voltage other than zero proportional to error voltage. This voltage is used to control the frequency of a VCO and is made such that polarity forces the VCO to track on the direction of the input reference frequency. Ones the two frequencies are equal and coincident (coherent), the error voltage of phase detector  26  is zero and PLL is then said to be locked. Channel PROM  23  enables to make rapid settle of counting ratios R and N according to a signal of microprocessor  13  in order to provide fast hops of frequency in the predestined band. 
     A communication terminal  7  shown on FIG. 4 comprises first transmitter  28  for radiation of an energy-transmitting signal through antenna  8 , data transceiver  29  for transmission/receiving data signal through antenna  9 , third frequency multiplier  30  which first and second inputs are connected respectively with second output of data transceiver  29  and first output of a first frequency synthesizer  31 , and output of said multiplier  30  coupled with input of demodulator  32 . Furthermore communication terminal  7  comprises a fourth frequency multiplier  33  which first and second inputs are connected respectively with output of modulator  34  and second output of a first frequency synthesizer  31 , and output of said multiplier  33  is coupled with second input of data transceiver  29 . Moreover a communication terminal  7  contains microprocessor  35 , which output (referred as Tx) is connected with output of modulator  34  and input (referred as Rx) is connected with output of demodulator  32 . The input/output (bidirectional port) of a microprocessor  35  (referred as LAN) is connected with appropriate port of next microprocessor  7  to combine local area network (LAN) in the event that toll gates comprise several communication terminals to provide high capacity of coexisting passages for noncontact IC card possessors, for example underground toll gates, or multi line highway. In addition LAN port of microprocessor  35  provide communication with a host plaza computer (not shown on the drawings) to enable complete toll charge and other financial operations. Furthermore a communication terminal  7  comprises a second frequency synthesizer  36  to provide carrier frequency of an energy-transmitting alternating field and reference oscillator  37  performing a reference frequency for synchronization of said first and second frequency synthesizers  31  and  36  as well as the every of frequency synthesizers comprised and operating in a two-way radio-based electronic toll collection system and arranged within IC cards. 
     A communication terminal  7  operates as follows. Microprocessor  35  produce a code of a predetermined frequency of an energy-transmitting signal f 1 , which frequency is defined by a current acting federal restrictions in this zone or country and by a particular application of a two-way radio-based electronic toll collection system. For example, on a highway toll gate (see FIG. 8 a ) wherein communication terminals are placed distantly from a passing vehicles, the carrier frequency f 1   1  of an energy-transmitting signal may be either less than 1 MHz or about 100 MHz, or above, and serves like a substitute of an energy-transmitting signal f 1  to synchronize the in-vehicle unit  10  which regenerates the energy-transmitting alternating field in order to power the noncontact IC card. Next example, parking collection (see FIG. 8 b ) wherein a vehicle is proximate to toll gate, the carrier frequency f 1  of an energy-transmitting signal may be either less than 1 MHz, a several MHz or 13.56 MHz that is permitted by restrictions and therefore a radiated a signal has enough strength to power directly a noncontact IC Card. Herein the in-vehicle unit measures the field strength of an energy-transmitting signal f 1  and do not regenerate the energy-transmitting signal because the source signal has enough strength to power IC card. Additional example is shown at FIG. 8 c,  wherein a several persons are passing through the underground toll gate. Herein a card possessors are proximate to communication unit  7  which radiates an energy-transmitting alternating field at frequencies of a permitted band, let&#39;s say 13.56 MHz for example, and people have no any necessity to handle in-vehicle unit or like. Hence, the carrier frequency f 1  of an energy-transmitting signal is always set up by program of microprocessor  35  in accordance with the application circumstances. 
     In-vehicle unit  10  illustrated on FIG. 5 comprising transceiver  38 , voltage comparator  39 , clock conditioner  40  and frequency synthesizer  41  (performs PLL frequency synthesizer), and a microprocessor  42  to settle the frequency of an energy-transmitting signal. In details, in the occasion of the utilization of noncontact IC card  1  having a parallel resonant circuit tuned to 125 kHz for deriving the energy, the microprocessor output code installs the frequency synthesizer to produce f 1  of 125 kHz, and in the event of the utilization of noncontact IC card  1  having a parallel resonant circuit tuned to 13.56 MHz for deriving the energy, the microprocessor output code installs the frequency synthesizer to produce f 1  equal to 13.56 MHz. For this purpose the antenna  11  comprises three different coils, not illustrated on FIGS. 1 to  10  as it is well known design. This design enable to operate within a wide spectrum of a frequencies (hundreds of kilohertz as the first band and several megahertz to 13.56 MHz as the second band). In order to provide resonant mode of antenna  11  has an appropriate capacitors arranged within transceiver  38  and as this technique is well known we do not complicate with description of this circuit. The second output of a microprocessor  42  guides the transceiver  38  to switch the appropriate coils to the output cascade. Voltage comparator  39  is designed to verify strength of a received energy-transmitting electromagnetic field from roadside terminal  7  and to produce a signal to enable the oscillation of internal VCO (not shown separately from frequency synthesizer since it is well know element) of the frequency synthesizer  41 . A clock conditioner  40  serves to provide a frequency synthesizer  41  with a shaped stable frequency reference which is derived from a synchronized substitute signal f 1   1  radiated by road communication terminal  7 . Moreover this signal outputted from clock conditioner  40  is examined in a microprocessor  42  to calculate the control codes to set frequency synthesizer  41  and transceiver  38 . 
     The receiving part of transmitter  38  scrolls the appropriate frequency band to select and recognize the energy-transmitting alternating field f 1  or it&#39;s substitute f 1   1 . When any signal is detected the voltage comparator  39  provide verification of a strength of received signal and in the event of a low voltage level comparator  39  enables the frequency synthesizer  41  to work. This low level is associated with f 1   1 , and high level is associated with f 1 . 
     A two-way radio-based electronic toll collection method and appropriate system operate as following. 
     The first step is to provide with communication terminal having capability of radiation an energy-transmitting signal in one band and frequency hopping ability in the other band in order to establish communication link for data transfer. 
     The second step is furnishing with a noncontact card capable to derive power supply voltage from an energy-transmitting alternating field. Next step is to support an IC card with a frequency hopping ability to establish communication link for data transfer. 
     Additional step is furnishing a moving object with an in-vehicle unit capable to measure the strength of an energy-transmitting signal and regenerate energy-transmitting signal when necessary. 
     In details, referring to the FIG. 9 a  depicting operation of a communication terminal  7 , a radiation of an energy transmitting present continuously in a toll-gate area when a distance between terminal  7  and moving vehicle or other possessor of a noncontact IC  1  card allows to provide adequate energy transfer to power IC card  1 . In the event of big distances, that relates essentially to high-ways, a terminal  7  radiates a substitute signal telling when detected that a vehicle have reached a toll-gate capture area. Simultaneously the terminal  7  provide scrolling of operating hopping channels to detect request from a new noncontact IC card when entered into capture area. When new IC card is found, the terminal  7  transmits code of hopping sequence to synchronize communication up-and-down link along with transmission of an appropriate information for authentication, security and toll charge. 
     FIG. 9 b  illustrates the operation of an noncontact IC card  1 . Before receiving energy-transmitting signal an IC card is idle. After an energy-transmitting signal is received and detected, the card is powered and starts to scroll the operating frequency band to detect one of the available channels. Afterward this channel is found the card transmits a request to establish a communication link. This request contains all necessary authentication data to recognize the IC card. Since the code of hopping sequence for synchronization of a communication link is received, the IC card  1  provides tracking to frequency hopping channels and data interchange occurs within this said channels. The command to hop is transmitted by terminal  7  by one of the known methods, for example each packet of data from terminal  7  is added with a channel code for next packet of information to be inputted in or outputted from IC card. Accordingly the bi-directional data transfer and toll collection are provided. In the cause of a small balance amount of a prepaid on-card value, the data with debt amount and bank account of this particular toll collection station-creditor is recorded into the IC card memory. Next time as the card is inserted to be recharged into ATM machine, the last makes automatically money transfer to a creditor. 
     FIG. 9 c  illustrate the operation of in-vehicle unit  10 , which scans to detect the energy-transmitting alternating signal. Afterwards the signal is found, the in-vehicle unit  10  makes an analyze whether is it an energy-transmitting signal by measuring the strength of alternating field. If the strength is adequate to power a noncontact IC card  1 , the in-vehicle unit keeps quiet and do not generate. If the strength of received signal is less then required in that case it is considered to be the substitute signal, and the in-vehicle unit regenerates the energy-transmitting signal of predestined frequency which is synchronized with said substitute signal. 
     Since an untraceable electronic check which communicate in a cryptographically sealed envelope with opener is a well known process we do not discuss this procedure in details. Transaction linkage data is utilized in each phase of the complete toll payment transaction to facilitate simultaneous multi-lane RCS/IVU operation. A plaza computer local area network with downlink communication terminal controller is also used to facilitate simultaneous multi-lane transactions 
     As a result the invention allows to merge the convenience of a conventional noncontact radio frequency cards with advanced performances of a complicated apparatuses, like present modern an in-vehicle units for automatic toll collection, comprising functions of a reading/writing from IC cards and transmitting payment information to a distant road collection station. Herein the operating distance is increased and the simultaneous stable non-collision and non-interference operation of a several cards is provided. Furthermore the hopping communication channels support the preventing of interception and easy decoding and deciphering of radio-frequency signal with an attempt of a tempering. 
     Moreover, the present invention shortens the time of passing through the toll gates, because if prepaid balance is not enough to pay, the debt is recorded into the IC card memory and the next card entering into an ATM machine is accompanied with payment of all previous debts. Besides, the eliminating of reader/writer functions from in-vehicle unit prevents a possibility of hacking of in-vehicle unit with a purpose to avoid reader/writer and send a fraud information about money transfer. 
     Next advantage of a preferred embodiment is versatility of the noncontact IC card which may, like present modern IC cards do, to store prepaid value, keep the balance and refund debt automatically while the next operation of money charging into card occurs. The same card may be used in many applications with and without the in-vehicle unit like in automatic vehicle identification, parking, in real-time highway toll collection systems, in public transportation for fare collection, and remote authentication. 
     Additional advantage of a preferred embodiment is that it provides a low cost solution of a system, because the noncontact IC card is built using the already created inexpensive production technology of internal spiral coil antenna for conventional economical and standard RF Cards. Using the same technology the printing of a conductive strip antenna do not add significant price. 
     The other advantage of a preferred embodiment is a low cost of in-vehicle unit as it does not participate in data transmission, reading/writing from/to the card and balance calculation, and all gadget displays are eliminated. 
     The non-contact IC cards used in such a systems are considered to be a conventional size and, in general, a noncontact card has the shape of a portable member and a size generally equal to that of ordinary magnetic cards having internal coil antenna formed as a spiral copper foil pattern by etching or the like.