Authorization system and authorization method

An authorization system for authorizing an IC card is provided. When an IC card--storing a different code from the code proper to an in-vehicle device and yet having been authorized by the in-vehicle device--inserted to the invehicle device, the system allows the in-vehicle device to authorize the IC card and vice versa. In other words, when an IC card having a different code from the proper code to the in-vehicle device is inserted into the in-vehicle device, an on-road apparatus disposed at a tollgate rewrites the code stored in the in-vehicle device to agree with the code stored in the IC card. As a result, the codes of the in-vehicle device and the IC card agree with each other, and thus the IC card can be authorized.

FIELD OF THE INVENTION
 The present invention relates to an authorization system and an
 authorization method both employed in an electronic toll collection system
 which collects tolls through unmanned tollgates. More particularly, it
 relates to the system and method that allow an in-vehicle-device to
 authorize an access of an IC card to the in-vehicle-device when the IC
 card has been authorized but has a different code from the code proper to
 the in-vehicle-device.
 BACKGROUND OF THE INVENTION
 An electronic toll collecting system automatically collects tolls by
 wireless communications between tollgates and vehicles on toll roads. This
 system allows vehicles to pay a toll keeping on driving and thus free from
 stopping at a tollgate. Therefore, this system can save manpower and
 alleviate traffic jam.
 An authorization system for authorizing a vehicle by an IC card is
 available as one of these electronic toll collecting systems. The
 following elements make up the authorization system overall:
 an IC card;
 an in-vehicle-device for reading the IC card and processing the
 information; and
 an on-road apparatus mounted to a tollgate. The on-road apparatus
 automatically collects tolls by communicating data to a central processing
 unit (CPU) in an operation center.
 When the IC card is inserted into a slot of the in-vehicle-device, the card
 and device try to authorize each other. When a code stored in the
 in-vehicle-device agrees with a code stored in the IC card, an
 authorization is established and the IC card authorizes the
 in-vehicle-device.
 On the other hand, the in-vehicle-device can also authorize the IC card,
 and detects an agreement of the codes. The device detecting the code
 agreement communicates the on-road apparatus to authorize each other. When
 the respective codes agree with, they can authorize each other. Then the
 on-road apparatus starts communicating the CPU in the operation center
 about automatic toll collection.
 When the code of IC card does not agree with the code of in-vehicle-device,
 although the in-vehicle-device and on-road apparatus authorize each other,
 the in-vehicle-device and the IC card cannot authorize each other.
 As such, the conventional authorization system requires two-step
 authorizations i.e. the on-road apparatus authorizes the
 in-vehicle-device, and the device authorizes the IC card, and these three
 elements should store the code in common with them. Therefore, if one of
 the on-road apparatus, in-vehicle-device, or IC card has a code different
 from the common code, the authorization cannot be established among them.
 SUMMARY OF THE INVENTION
 The present invention addresses the problem discussed above and aims to
 provide an authorization system and an authorization method through which
 an IC card having been authorized and yet storing a code different from
 the code proper to an in-vehicle-device can be authorized by the
 in-vehicle-device.
 In a two-step authorization system, i.e. an on-road apparatus authorizes
 the in-vehicle-device, and the in-vehicle-device authorizes an IC card,
 the authorization system of the present invention operates as follows.
 When the in-vehicle-device receives an IC card having a code different
 from the code proper to the device, the device communicates the on-road
 apparatus. Then the apparatus rewrites a code of the in-vehicle-device to
 agree with a code of the IC card so that the in-vehicle-device identifies
 the IC card as an authorized one. Thus an authorization is established
 between the IC card and the in-vehicle device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
 An exemplary embodiment of the present invention is demonstrated
 hereinafter with reference to the accompanying drawings.
 FIG. 1 is a block diagram illustrating an overall structure of an
 authorization system of the present invention.
 IC card 10 stores an ID number, a vehicle class, a travelling route,
 settlement of an account, and a code for authorization. In-vehicle-device
 20 stores a code for authorizing IC card 10, and includes communicating
 section 21 for communicating on-road apparatus 30 about toll collection by
 reading information recorded in IC card 10. On-road apparatus 30 is
 disposed at a tollgate and equipped with the following elements:
 (a) communicating section 31 for communicating in-vehicle-device 20 about
 collecting tolls;
 (b) memory 32 for storing every possible code to be used in communications
 in the authorization system, such as code A, code B and code C as recited
 in FIG. 1; and
 (c) communication network 33 for communicating operation center 40.
 The every possible code discussed above means every authorized code which
 is permitted to use in this authorization system. The IC cards storing
 these codes are produced only by designated manufacturers, and the IC
 cards do not authorize other IC cards having different coding systems.
 An operation of this authorization system of the present invention is
 demonstrated hereinafter with reference to FIG. 1 and FIG. 2.
 The in-vehicle device 20 has a code or cipher. The IC card 10 also has a
 code or cipher which is the same as or different from that of the code or
 cipher of the in-vehicle device 20. The on-road apparatus 30 has a
 plurality of codes or ciphers, all of which are allowed to be used in the
 electronic toll collecting system by a managing agency of the electronic
 toll collecting system.
 Each of the codes or ciphers has a construction consisting of code key and
 coded data. The coded data is coded under the code key. In an exemplary
 embodiment of the present invention, the code agreement is performed by
 comparing each of the coded data between the IC card 10 and the in-vehicle
 device 20; and between the in-vehicle device 20 and the on-road apparatus
 30. If the code keys are coincident with each other, the code agreement
 occurs. The comparison may be accomplished by performing an exclusive OR
 function between the respective coded data. Code agreement may be
 indicated, for example, by deriving a "1" from the exclusive OR function.
 Communication between transceiver 31 and transceiver 21 is accomplished,
 for example, as shown in FIG. 3.
 When the code or cipher of the IC card 10 agrees with the code or cipher of
 the in-vehicle device 20, the agreed code or cipher is transmitted to the
 on-road apparatus 30. The on-road apparatus 30 checks it whether the code
 or cipher is the allowed one by the managing agency of the electronic toll
 collecting system. If the code is the allowed one, the IC card is
 available for the electronic toll collecting system. If not, the IC card
 is rejected by the electronic toll collecting system.
 If the code or cipher of the IC card 10 or the in-vehicle device 20 is not
 the allowed one (which is stored in the on-road apparatus 30), a car with
 the in-vehicle device 20 not having an allowed code is rejected for
 electronic toll collecting.
 Signal transmission between the on-road apparatus 30 and a car mounting the
 in-vehicle device 20 is performed when the car passes through a tollgate.
 Therefore, the on-road apparatus 30 recognizes the in-vehicle device 20
 with car by car. In this manner, interference between transmissions from
 different cars is prevented.
 First, IC card 10 is inserted into slot 22 of in-vehicle-device 20 on Step
 1 (hereinafter Step is referred to as S). IC card 10 in slot 22 and
 in-vehicle-device 20 try to authorize each other with an agreement of the
 codes stored in the respective elements on S2. When both the code agree
 with, the authorization is established, and device 20 authorizes IC card
 10 on S3. IC card 10 also authorizes device 20.
 When IC card 10 and in-vehicle-device 20 store code A respectively, an
 authorization is established on S3 because both the codes agree with.
 Device 20 then analyzes the information recorded in IC card 10 and
 transmits it to communicating section 31 of on-road apparatus from
 communicating section 21 on S4. On-road apparatus 30 transmits the
 received information to operation center 40 on S5. Operation center 40
 calculates the toll to be collected based on the received information, and
 transmits the information about the toll to be collected to on-road
 apparatus 30 on S6. Apparatus 30 rewrites a settlement of account of IC
 card 10 based on the toll information on S7, which completes a toll
 payment.
 When the code of apparatus 30 does not agree with the code of IC card 10 on
 S2, i.e. when IC card 10 storing code B is inserted to in-vehicle-device
 20 storing code A, device 20 determines that authorization cannot be
 established and detects disagreement of the codes.
 When detecting the disagreement of the codes, device 20 informs on-road
 apparatus 30 of the disagreement on S8. Device 20 and apparatus 30 try to
 authorize each other also on S8. In this case, since apparatus 30 stores
 codes A, B and C while device 20 stores code A, the two elements authorize
 each other because of agreement of the codes.
 Once the code agreement is confirmed on S9, in-vehicle-device 20 transmits
 the information of code-disagreement between device 20 and IC card 10 to
 on-road apparatus 30 on S10 Apparatus 30 receives this information, then
 transmits another code, e.g. code B, to device 20 on S10. Device 20 then
 overwrites code A with code B on S12. In other words, code A recorded in
 device 20 is replaced with code B. Device 20 storing code B determines
 again whether or not the code agrees with that in IC card 10 with code B
 on S13. When the codes agree with, the operation proceeds to S3, and the
 authorization between IC card 10 and in-vehicle-device 20 is established.
 If the codes still do not agree with on S13, the authorization is not
 established yet, but the steps S8 through S13 should be repeated thereby
 establishing the authorization without fail.
 In the demonstration discussed above, the information determined by device
 20 of the code disagreement between in-vehicle-device 20 and IC card 10 is
 transmitted from device 20 to on-road apparatus 30 on S10. However, the
 information about which codes are stored in IC card 10 can be transmitted
 instead of the determined information of the code disagreement. In this
 case, after confirming the code agreement between in-vehicle-device 20 and
 on-road apparatus 30 on S9, device 20 transmits the information about the
 codes stored in IC card 10 to apparatus 30 on S14. On-road apparatus 30
 receives the information and transmits the code information recorded in IC
 card 10 to in-vehicle-device 20 on S15, then the operation proceeds to S12
 and S13 which have been already detailed. This case results in a code
 agreement without fail on S13. Therefore, repetition of steps of S8
 through S13--required when an authorization cannot be established--is not
 needed, and the authorization between device 20 and IC card 10 can be
 immediately established.
 The access of an IC card to an in-vehicle-device can be thus authorized.
 In the two-step authorization system, i.e. an on-road apparatus authorizes
 an in-vehicle-device, and the in-vehicle-device authorizes an IC card, the
 present invention thus allows the system to operate smoothly even if
 another IC card--having a code different from the code proper to the
 in-vehicle-device--is inserted into the in-vehicle-device. Because this
 another card can be identified through data communication between the
 in-vehicle-device and the on-road apparatus as the IC card having been
 authorized by the in-vehicle-device. As a result, the system collects
 tolls smoothly regardless of what kind of codes an IC card stores.
 Communication between several vehicles may be accomplished as shown in FIG.
 4. In the example, the number MDS.sub.D slots is four, the number of
 MDS.sub.U slots is three, the number of ACTS slots is one.
 FCMS sends the data to all of the vehicles.
 Vehicle A through vehicle D are sent "Registration ID" to ACTS.
 Vehicle B sends data by MDS.sub.U (3), and receives data by MDS.sub.D to
 (1).
 Vehicle C sends data by MDS.sub.U (1), and receives data by MDS.sub.D (2).
 Vehicle E sends data by MDS.sub.U (2),and receives data by MDS.sub.D (3).
 Vehicle F receives the data of MDS.sub.D (4).
 The format for the Frame Control Message slot is shown in FIG. 5.