Description

SYSTEM AND METHOD FOR CANCELING IPPV

PURCHASING PROGRAM OF VIDEO/AUDIO CHANNEL AND

MUSIC CHANNEL OF DMB SYSTEM

Technical Field

[1] The present invention relates to a system and method for canceling an impulse pay- per-view (IPPV) purchase of a program of a video/audio channel or a music channel in a digital multimedia broadcasting (DMB) system, and more particularly to a system and method for canceling an IPPV purchase of a program of a video/audio channel or a music channel in a DMB system, which provides a purchase cancellation function for canceling the purchase of contents which have been purchased in an IPPV manner of paying a fee for every program viewed through a digital broadcast receiving terminal. Background Art

[2] FIG. 1 is a view illustrating the entire configuration of a general satellite digital multimedia broadcasting (DMB) system.

[3] Satellite DMB provides a service of enabling the user to receive multimedia information, including text data/audio/video and electronic program guide (EPG) information, through not only a fixed receiver, but also through a personal mobile terminal or vehicle-mounted terminal by means of a broadcasting satellite or communication satellite.

[4] The satellite DMB service, which is a convergence service of broadcasting and communication, enables broadcast contents provided from a program provider (PP) to be broadcasted through a satellite DMB broadcasting center and a satellite. Also, the satellite DMB service enables a digital broadcast receiving terminal to receive broadcast program signals, including a video and audio signal for text broadcasting, data for data broadcasting, entitlement control message (ECM) information, entitlement management message (EMM) information, and EPG information (which contains program specific information (PSI) and service information (SI)), and to provide broadcast video and audio signals to a viewer. In addition, the satellite DMB service provides traffic information, news, weather information, shopping information, movies, music broadcasts, sports broadcasts, and living information.

[5] According to such a conventional satellite DMB service, a digital broadcast receiving terminal receives a digital broadcast signal, and demodulates the received digital broadcast signal in cooperation with a conditional access system (CAS) so as to produce a high-quality broadcast video and/or audio signal and broadcast data, thereby allocating various broadcast contents to be utilized. However, the conventional DMB

system has a problem in that the system does not provide a purchase cancellation function for canceling the purchase of contents which have been purchased in the IPPV or PPV manner provided in video/audio channels or music channels. Disclosure of Invention

Technical Problem

[6] Therefore, the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a system and method for canceling an IPPV purchase of a program of a video/audio channel or a music channel in a DMB system, which provides a purchase cancellation function for canceling the purchase of contents which have been purchased in an impulse pay-per-view (IPPV) manner of paying a fee for every program viewed through a digital broadcast receiving terminal. Technical Solution

[7] In order to achieve the above-mentioned object, there is provided an impulse pay- per-view (IPPV) purchase cancellation system for a video/audio channel or a music channel in a digital broadcasting system, the IPPV purchase cancellation system including: a callback server for receiving a purchase history and a purchase cancellation history from a digital broadcast receiving terminal; a business information system (BIS) for receiving an IPPV purchase history and a purchase cancellation history from the callback server, providing an account settlement function, managing IPPV request entitlement and a usage limit, granting IPPV request entitlement to adult subscribers, establishing IPPV request entitlement of teenager subscribers and an adult-only content viewing limit function (i.e. a block-out function) for teenager subscribers, setting a limit on a monthly usable amount of money, managing a total usage limit and an accumulated usage history according to each SIM/SMD card of the digital broadcast receiving terminal, and managing the number of tokens required according to IPPV program price information; a conditional access system (CAS) for transmitting an entitlement control message (ECM) and an entitlement management message (EMM) to the digital broadcast receiving terminal; and a program specific information/service information (PSI/SI) system connected to a program management system (PMS), the PSI7SI system transmitting broadcast PSFSI (e.g. EPG information) to the digital broadcast receiving terminal, wherein the CAS is connected to the PMS, sets an IPPV usage limit of the digital broadcast receiving terminal of a subscriber, manages a total usage limit (i.e. debit limit) and purchase, and restricts adult-only programs from being illegally viewed and broadcast programs from being illegally viewed by a user for whom service has been temporarily revoked.

[8] According to another aspect of the present invention, there is provided a method for

canceling an impulse pay-per-view (IPPV) purchase of a video/audio channel or a music channel in a digital broadcasting system, the method including the steps of: (a) when a digital broadcast receiving terminal joins as a subscriber or makes an additional request, receiving an IPPV and an adult-only content viewing limit (i.e. block-out) for teenagers, receiving broadcast video and audio signals, an entitlement management message (EMM), an entitlement control message (ECM), EPG information (i.e. PSI/SI information) from a DMB broadcasting service system, checking channels programs through an EPG main, receiving a channel number, and checking if a channel of the received channel number can be viewed; (b) shifting to a PPV channel, determining if there is an IPPV product, checking a viewing right, determining if the PPV channel corresponds to a usage-restricted channel, or if there is an adult-only content viewing restriction (i.e. block-out) for teenagers, checking an adult-only genre, inputting a PIN/ password, and allowing a broadcast to be viewed; (c) when it is impossible to view the broadcast, outputting an announcement about subscription, or outputting an announcement about a usage-restricted channel/program in a case related to an adult-only content viewing limit (i.e. block-out) for teenagers; (d) outputting an announcement about termination when a purchasable time has been exceeded because an IPPV program can be purchased only during the purchasable time; (e) only when a corresponding subscriber is a subscriber who can normally purchase and view an IPPV program, viewing preview contents during a broadcast program preview time, and viewing the IPPV program through the digital broadcast receiving terminal via a purchase step during a buy time; (f) after the IPPV program has been purchased, allowing the digital broadcast receiving terminal to cancel the purchase of the IPPV program via an IPPV program purchase cancellation step before a purchase-cancelable time (cancel-time; Ctime) expires, wherein the digital broadcast receiving terminal includes an application for a purchase cancellation function, and when a purchase cancellation is performed and completed according to a predetermined process, a purchase cancellation history is stored in a SIM/SMD card, and the stored purchase cancellation history is transmitted to a callback server; (g) updating and storing information about an IPPV purchase history in the SIM/SDM card within a range not exceeding a usage limit, deleting tokens as many as the number of used tokens, storing an IPPV purchase history and a purchase cancellation history in a memory of the terminal, and performing a termination after viewing; and (h) transmitting a purchase history and a purchase cancellation history of IPPV programs to the callback server in a predetermined scheme at a predetermined time, which are established according to a determination of a service provider.

Advantageous Effects

[9] The system and method for enabling a digital broadcast receiving terminal to cancel an IPPV purchase of a video/audio channel or a music channel according to the present invention provides a purchase cancellation function of canceling a purchase of contents purchased in the IPPV or PPV scheme, which requests a fee to be paid for every program viewed through the digital broadcast receiving terminal. In addition, a purchase history and a purchase cancellation history may be stored in a SIM card of a DMB terminal and may be managed, or the histories may be managed by a callback server. Brief Description of the Drawings

[10] The foregoing and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:

[11] FIG. 1 is a view illustrating the configuration of a general satellite digital multimedia broadcasting (DMB) system;

[12] FIG. 2 is a view illustrating the configuration of an impulse pay-per-view (IPPV) purchase request information return network;

[13] FIG. 3 is a block diagram illustrating the configuration of an IPPV callback system;

[14] FIG. 4 is a view illustrating the configuration of an IPPV program;

[15] FIG. 5 is a flow diagram illustrating a CAS callback processing produce;

[16] FIG. 6 is a flowchart illustrating a purchasing method of an IPPV terminal;

[17] FIG. 7 is a flowchart illustrating a purchase canceling method of an IPPV terminal;

[18] FIG. 8 is a view illustrating a flow of an IPPV service; and

[19] FIGs. 9 to 12 are views illustrating screens for an IPPV service.

Best Mode for Carrying Out the Invention

[20] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[21] FIG. 2 is a view illustrating the configuration of an impulse pay-per-view (IPPV) purchase history and purchase cancellation history return network.

[22] An IPPV purchase request information return network cooperates with a wireless data communication network, which includes a terminal, a base station (BS), a base station controller (BSC), a mobile switching center (MSC), a Packet Data Service Node (PDSN), and an AAA authentication server, and also cooperates with a TU media network (i.e. satellite DMB network) for receiving a satellite multimedia broadcast. In the following description, TU represents a satellite DMB service.

[23] FIG. 3 is a block diagram illustrating the configuration of an IPPV callback system.

[24] The IPPV callback system includes a digital broadcast receiving terminal 100, a callback server 200, a business information system (BIS) 300, and a conditional access

system (CAS) 400.

[25] The digital broadcast receiving terminal 100 includes a satellite DMB application program 110 for receiving a satellite DMB broadcast signal and electronic program guide (EPG) information, a conditional access (CA) module 120 for keeping adult-only programs from being illegally viewed and broadcast programs from being illegally viewed by either a non-subscriber or a user for whom service has been temporarily revoked, and a SIM/SMD card (hereinafter, referred to as a subscriber identity module (SIM) card 130, as shown in FIG. 3). The SIM card 130 has the IPPV function, stores information about IPPV viewing rights, and can store a purchase history and a purchase cancellation history of an IPPV event. Also, there is no restriction in a purchase history and a purchase cancellation history of an IPPV event, which are stored in the SIM card 130. In addition, since overwriting is automatically performed when the capacity of the memory in SIM card 130 is completely filled, a case where the amount of IPPV purchase history/purchase cancellation history exceeds the capacity of the memory does not occur.

[26] The callback server 200 receives IPPV purchase history/purchase cancellation history from the digital broadcast receiving terminal 100, stores the received IPPV purchase history/purchase cancellation history in a database, and transmits the IPPV purchase history/purchase cancellation history to the BIS 300.

[27] The BIS 300 manages IPPV request entitlement and a usage limit (i.e. debit limit), grants IPPV request entitlement to adult subscribers, establishes IPPV request entitlement and a block-out function (which is a function of limiting teenagers from viewing adult-only contents) for teenagers, sets a monthly debit limit (e.g. within 10,000 won per month), manages a total debit limit and an accumulated usage history according to each SIM card, allocates IPPV program goods, defines the number of tokens (i.e. event cost) required according to price information, and performs a settlement function according to an IPPV Personal Identification Number (IPPV PIN) code reset and IPPV request information received from the callback server 200.

[28] The CAS 400 receives a conditional access (CA) schedule from a program management system (PMS), and transmits an entitlement control message (ECM) and an entitlement management message (EMM) to the digital broadcast receiving terminal 100.

[29] At the same time, a PSI7SI system connected with the program management system

(PMS) transmits program specific information/service information (PSI/SI), i.e. EPG information, to the digital broadcast receiving terminal 100.

[30] The CAS 400 is connected with the program management system (PMS), sets an

IPPV debit limit of each subscriber terminal, manages debit limits and customer purses, and keeps adult-only programs from being illegally viewed and broadcast

programs from being illegally viewed by either a non-subscriber or a user for whom service has been temporarily revoked.

[31] The CAS 400 manages one or more PINs (that is, identification numbers for the use of service, e.g. TU PINs) stored in smart cards, and can change or initialize a PIN code stored in a memory or a SIM card 130 of the digital broadcast receiving terminal 100 by means of the EMM of the CAS 400. The PINs managed by the CAS 400 are used in an identification process upon an IPPV purchase and a purchase cancellation.

[32] According to a CAS processing flow for access to an IPPV channel, an IPP service subscription checking function, a block-out checking function, a pre-purchase checking function, and a preview time/purchasable time checking function are performed.

[33] The callback server 200 receives an IPPV purchase history from the digital broadcast receiving terminal 100 according to the IPPV-related functions of the CAS, and stores the IPPV purchase history information. The cases of performing a callback for an IPPV purchase history include: a case where there is an IPPV purchase history (i.e. a request history) when a TU mode is switched off (for example, when a TU service end button, i.e. a general communication end button, has been pressed, when an end button has been pressed for a long time so as to switch off a terminal, when a call is received and connected during viewing, when an MMS is received and connected during viewing, and when the terminal accesses a wireless Internet during viewing); a case where there is an IPPV event purchase history when the user attempts to purchase an IPPV event; and a case where a requested purchase has been rejected, wherein, upon a failure in a callback, it becomes impossible to purchase an IPPV purchase event in the future. Such a IPPV purchase and purchase history callback policy is determined by each service provider, and may be operated in such a manner as to perform a callback once every predetermined number of times of purchase.

[34] It should be noted that a callback for IPPV request information can be performed in all types of networks, including 2G, 2.5G, 3G, and 4G networks.

[35] Contents recorded at every IPPV request include a service ID, an event ID, a buy time (date and time), a total debit limit, and a customer purse.

[36] The service ID corresponds to information (i.e. the number of a channel used for purchase) about the channel through which a purchase-requested IPPV event has been broadcasted.

[37] The event ID is a unique ID (i.e. a PSI/SI event ID) for each purchased program, and corresponds to the code (e.g. 0-65535) of a purchase-requested event.

[38] The buy time represent a time when an IPPV event is purchased.

[39] The total debit limit represents the number (e.g. a value within a range from 0 to

65535) of tokens for the total debit limit stored in the SIM card 130 of the digital

broadcast receiving terminal 100.

[40] The customer purse represents the accumulated number of usable tokens stored in the SIM card 130 of the digital broadcast receiving terminal 100.

[41] FIG. 5 is a flow diagram illustrating a CAS IPPV-related callback processing produce.

[42] A CAS manages one or more PIN codes (e.g. TU PINs) recorded in smart cards, and can initialize and change a PIN code stored in a SIM/SMD card by transmitting an EMM.

[43] The CAS supports three PIN codes, that is, a parental code, an IPPV code, and a general code. All the three codes are stored in a smart card. The CAS supports a function of comparing PIN codes stored in the smart card.

[44] In order to compare PIN codes stored in the smart card, an EPG program uses an

EPG_MSG_PIN_CODE_CHECK message.

[45] As shown in FIG. 5, the comparison is performed based on a query and control scheme of communicating between the terminal s EPG program and a CAS task.

[46] When it is a callback time point appointed by a DMB broadcasting service company

(when it is a DMB broadcast viewing end time point or purchase time point in a case of TU media), an EPG must carry an EPG_MSG_IPPV_CALLBACK message (including an opcode of MSG_REQEST) in order to check if callback data exists in the CAS (except for vehicle-only terminals). The CAS transmits callback data with an opcode of MSG_RESPONSE in response to the EPG_MSG_IPPV_CALLBACK message.

[47] When receiving callback data, an EPG must carry the respective callback structure information callback_st, including a service ID, an event ID, a buy time, a total debit limit, and a customer purse, to the callback server, wherein a result of the transmission must be replied to the CA module only when the callback structure information has been completely transmitted. The reply is performed by using an EPG_MSG_Callback message, wherein a value of MSG_Response is used as an opcode. When the transmission has failed, no reply is sent to the CA module.

[48] When an event of an IPPV channel corresponds to an IPPV preview section, the

CAS transmits an EPG_MSG_IPPV_PREVIEW message to the EPG. The EPG_MSG_IPPV_PREVIEW message includes service_id (the number of a channel to which the event belongs), event_id (the ID of the event to be purchased), previewjime (a time when the preview will be terminated), token_type (a type of tokens required for purchasing the event), and token_amount (the number of tokens required for purchasing the event).

[49] When the user is to purchase an event of an IPPV channel or is to use a prepayment right for time, the EPG reports a purchase history to the CAS through an

EPG_MSG_IPPV_PURCHASE message. The EPG_MSG_IPPV_PURCHASE message includes: type (a value of determining whether the message corresponds to a prepayment right, an IPPV purchase, or a purchase cancellation, wherein the type has a PAY_BUY value upon purchasing a prepayment right for time, has an IPPV_BUY value upon purchasing an IPPV event, and has an IPPV_CANCEL value upon canceling an IPPV purchase), token_type (a type of tokens required for purchasing an event), service_id (the number of a channel to which the event belongs), event_id (the ID of the event to be purchased), token_amount (the number of tokens required for purchasing the event), PIN (information about the PIN of the user), Ctime (a time until which a corresponding purchase can be canceled), and result (a value resulting from processing of a requested purchase).

[50] A purchase request message transmitted from the EPG to the CA module extracts the value from an EPG_MSG_IPPV_PURCHASE_REPLY message, outputs the extracted value as a purchase-cancelable time on the screen. In a case of an event whose purchase cannot be canceled, the value is expressed as zero.

[51] When an EPG calls a CAS_Getstatus function in order to request purchase of a prepayment right or IPPV event, an opcode is set to MSG_REQUEST and a structure value is set to ppv_purchase_st. In contrast, when CAS relays a result of a requested purchase by means of a Notification function, an opcode is set to MSG_RESPONSE, pvParams has the structure value of ppv_purchase_st, as well, and the result is set to a value resulting from processing of a requested purchase. The pvParams has the structure value of ppv_purchase_st, as well, and the result is set to a value resulting from processing of a requested purchase.

[52] When the result has been set to ERR_PAYTV_BUY_ACCESS (CAS msg #E405 in

FIG. 11), it represents that a purchase has been successfully performed. Even with respect to a purchase cancellation request IPPV_CANCEL, when the cancellation has been successfully performed, an ERR_PAYBUY_SUCCESS code is returned.

[53] When the result has been set to ERR_PIN_VERIFICATION_FAILED (CAS MSG

#E402 in FIG. 10), it represents that a purchase has failed because a PIN value input for a purchase is different from the PIN value of a smart card.

[54] When the result has been set to ERR_PPV_CALLBACK_LIMIT (CAS msg #E358 in FIG. 9), it represents that there is data which has not been called back. Therefore, in this case, after a callback process is performed, a purchase procedure must be again performed.

[55] When the result has been set to ERR_NO_MORE_BUY_PPV (CAS Error msg

#E308 in FIG. 10), it represents that it is impossible to purchase another IPPV event because a debit limit has been exceeded.

[56] When the result has been set to ERR_EXPIRED_BUY_REFUND_TIME(CAS

MSG #E404 in FIG. 10), it represents that a time available for a purchase or purchase cancellation has been exceeded.

[57] The EPG can identify a purchase history of the user through the current screen by means of an EPG_MSG_SS_PPV message. A structure of pvParam responded by the CAS includes a result (which represents whether following data is effective, wherein following data is effective only when the result has a value of zero) and count (which corresponds to following purchase_log_st).

[58] Through the screen of a terminal, service_id (the number of a channel to which a purchase event belongs), Event_ID (a DVB Event ID of a purchased event), buy_time (a time when tokens or event information is purchased/consumed/canceled), amount (a token unit used for a purchase or consumption), and type (an identifier for distinguishing between purchase, consumption, and cancellation, for example, OxOD: IPPV purchase, and OxOE: IPPV purchase cancellation) are provided.

[59] FIG. 4 is a view illustrating the configuration of an IPPV program. In FIG. 4, an A section indicates a time (hereinafter, referred to as a purchasable time ) when purchases can be made, a B section indicates a preview time, and a C section indicates an IPPV program broadcasting time.

[60] There is no limit to playing time per program, and an account is settled by periodically collecting account information according to a settlement schedule.

[61] A subscriber to use an IPPV service must have an IPPV viewing right, which has been stored in the SIM card 130 of the digital broadcast receiving terminal 100, wherein the IPPV viewing right is granted to adult and teenager subscribers according to ratings established upon service subscription. A block-out function of the CAS is applied to teenager subscribers in order to restrict the teenagers from requesting and viewing adult-only contents. The teenager subscribers are restricted from viewing programs rated for those 19 years old or older, among IPPV channel programs. In addition the teenager subscribers have a limit in viewing based on a monthly debit limit. The adult subscribers may be restricted to viewing only programs rated for those 19 years old or older. A request history of to each subscriber is transferred to the callback server 200.

[62] A request and a viewing right control are performed by using the IPPV function of the CAS. In order to restrict teenagers from viewing programs rated for those 19 years old or older, the block-out function of the CAS is used.

[63] Fees for IPPV use may be different, which the CAS controls by using tokens. When the value of each token is set as 500 won, and a fee for use of a program is 5,000 won, 10 tokens are required. A monthly debit limit is controlled by using a total debit limit (DL) stored in a SIM card, and a customer purse (CP). The total debit limit and the customer purse are measured in units of tokens.

[64] The total debit limit is set to the max (65535) upon personalizing a SIM card, before the SIM card is put on the market.

[65] An IPPV program can be purchased during a purchasable time when purchases can be made, without regard to a preview time.

[66] FIG. 6 is a flowchart illustrating a purchasing method of an IPPV terminal, and

FIG. 7 is a flowchart illustrating a purchase canceling method of an IPPV terminal.

[67] First, referring to FIG. 6, when the user of the digital broadcast receiving terminal

100 joins as a subscriber or makes an additional request, IPPV and a block-out product are granted to the user.

[68] An EPG main receives a broadcast video/audio signal, an entitlement management message (EMM), an entitlement control message (ECM: CW, IPPV Product), EPG information (i.e. PSI/SI information) from the DMB broadcasting service (HE) system, identifies the programs of a premium channel, receives a channel number, and checks if there is an error code.

[69] When there is an error code, a subscription announcement is output based on the error code, or an announcement about use-restricted channels or programs is provided in the case where the error code corresponds to a Block-out.

[70] During a time when purchases can be made, it is possible to purchase an IPPV program. When the purchasable time has terminated, a termination announcement is provided.

[71] In the cases where the error code corresponds to either an error code of notifying that it is within a preview viewing time, or an error code of notifying that it is within the purchasable time, when it is within a broadcast program preview time, a preview is viewed, and when it is within a purchasable time when purchases can be made, a purchase announcement and a purchase request are transmitted through the callback server 200, and it is determined if there was a previous request.

[72] When a PIN code has been input to an EPG and is confirmed within three attempts after a purchase has been checked, an IPPV purchase history is updated within a range not exceeding a debit limit and the updated information is stored in a SIM card, the CP increases, and a record of an IPPV purchase event is recorded in a terminal s memory.

[73] * (Callback Error)

[74] Upon requesting an IPPV event purchase, if a callback has failed in a state where a purchase history exists, the digital broadcast receiving terminal displays a purchase- failure popup window (e.g. Purchase Unavailable, Please Try Again ) on the screen. Thereafter, when a confirmation button is pressed, the digital broadcast receiving terminal resumes TU, and then moves to a previous viewing channel.

[75] Upon terminating a TU service, if a callback has failed in a state where a purchase history exists, the TU service is terminated, and the purchase history is left without

being deleted.

[76] (IPPV PIN Code Error)

[77] The basic processing of an IPPV PIN code input error is based on the function of the CAS. When an input error of the PIN code occurs four times or more, and thus an input window is locked, it is necessary to call and request customer service to reset the IPPV PIN code (which is announced through a popup window). A subscriber recognizes the reset of the IPPV PIN code as a reset of a TU service password (see IPPV PIN code processing).

[78] When the number of times of input errors exceeds a predetermined number, a CAS block message for an IPPV PIN code input is used.

[79] According to an exemplary embodiment of the present invention, in the case of an

Epsilon card, when the number of IPPV event recorded in a SIM card exceeds a predetermined number, e.g., 255, the Epsilon card may be set to apply an automatic reset function to a SIM card 130, or may be set to automatically overwrite exceeded records on previous records.

[80] The SIM card 130 includes a function of the CAS, the customer purse in the digital broadcast receiving terminal 100 increases whenever an IPPV event, defined by an IPPV program use fee and the basic value of a token (i.e. by an event cost), is purchased, and an error occurs when a debit limit is exceeded upon requesting an IPPV program.

[81] Upon terminating a TU service, when there is purchase request information, the digital broadcast receiving terminal 100 requests a callback of the purchase request information to the callback server 200. Upon requesting an IPPV event purchase, when there is previous request information, the digital broadcast receiving terminal 100 requests a callback of the previous request information to the callback server 200, wherein, if the callback has failed, a separate exceptional processing is applied.

[82] Purchase record data and callback security are stored, without encryption, in an area in which data is not deleted, even when data stored in an NVRAM of the digital broadcast receiving terminal 100 is upgraded by software of the terminal. According to an exemplary embodiment of the present invention, a purchase history and/or a purchase cancellation history may be stored in a memory, in a SIM/SMD, or in both according to the policy of each manufacturing company, and may be encrypted.

[83] A graphic user interface (GUI) of the digital broadcast receiving terminal 100 uses a soft-key scheme, includes an IPPV flow, wherein types of service channels include a video channel, an audio channel, a music channel, a PPC channel, and a PPV channel.

[84] Hereinafter, a purchase cancellation procedure will be described. As shown in FIG.

7, when a purchase cancellation is selected from a menu during viewing after an IPPV has been purchased, it is determined if the current time is within a time when the

purchase can be canceled. If the current time is past the time when the purchase can be canceled, the selected purchase cancellation is ignored.

[85] In contrast, if the current time is within the time when the purchase can be canceled, the user is requested to input a password. When the password is input by the user and is confirmed, the CAS restores the CP to the original state, and a purchase cancellation history is stored. Then, a callback message according to the purchase cancellation is transmitted to the terminal, and the user is restricted from using (e.g. viewing) the corresponding program.

[86] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

[87] FIG. 8 is a view illustrating a flow of an IPPV service which requests a fee to be paid for each viewed program. FIG. 8 illustrates a scenario until a callback is performed after a digital broadcast receiving terminal has completed a purchase, upon a first access to an IPPV channel. In the scenario, only colored steps are processed through a user interface (UI), and numerals attached to the colored steps are identical to screen numbers in following drawings. Checking if a corresponding PPV channel is an adult-only channel, a use restriction based on program ratings, etc., are performed before the first step, i.e. at the precise moment when the user accesses the PPV channel.

[88] It is determined if there is IPPV product information on a smart card. When there is no IPPV product information on the smart card, the user joins in IPPV service, so that IPPV product information is transmitted to the smart card.

[89] When there is IPPV product information on the smart card, it is determined if a corresponding program has been blocked-out. When the program has been blocked-out, it is impossible to view and purchase the program (see reference numeral 1-1). When the program has not been blocked-out, an adult verification password is checked through a PPV purchase, and the program is viewed.

[90] It is determined if a PPV event has already been purchased through the IPPV. Then, if the PPV event has not been purchased, it is checked if a preview has expired. When the preview has not expired, the preview is checked (see reference numeral 2), an IPPV purchase history is checked, and a callback must be carried out before the PPV event can be purchased (see reference numeral 3).

[91] When there is no IPPV purchase history, a coverage and a battery are checked, it is determined if a CAS PIN has been locked, it is checked if the user has been authenticated by inputting a PIN, and the user contacts customer service when a debit limit has been exceeded, i.e. when no credit remains, (see reference numerals 4 and 5).

[92] After authentication of the PIN, when the purchase of broadcast data has been completed (see reference numeral 6), a broadcast is viewed, and, when the TU has

been terminated, a callback must be carried out by checking if there is an IPPV purchase history before the next IPPV program can be purchased (see reference numeral 7).

[93] In a normal case, an IPPV service is provided via steps indicated by reference numerals 2, 4, 5, 6, and 7.

[94] FIGs. 9 to 12 are views illustrating screens for an IPPV service.

[95] Although a program name and a price are individually input upon input of EPG information in a TU terminal, the program name and the price are unitedly transmitted as the program name upon transmission of EPG data. Therefore, it is unnecessary to configure a separate mini-EPG for a PPV channel in the terminal.

[96] According to an exemplary embodiment of the present invention, an EPG menu may not provide an IPPV-related menu, such as a purchase history inquiry.

[97] Upon joining in a TU, all subscribers are granted IPPV products. However, additional service users who are restricted from using an IPPV service are not granted an IPPV product.

[98] In an IPPV service, a block-out filter is applied and used for channels and programs. When a channel or program has been blocked out, a loading animation is stopped while a popup window is opened.

[99] Referring to FIG. 9, only when an event information table EIT(p) has been received, a lower purchase banner is displayed, and a purchase function is activated. When a cancellation is selected in a state where the purchase banner has been displayed, the purchase banner disappears, and the channel is shifted to a previous viewing channel.

[100] When an L button is pressed in the current screen, a mini-EPG is displayed while the purchase banner disappears. When the mini-EPG has disappeared, the purchase banner is again displayed. hh:mm represents a buy-time duration based on a start time, and is expressed as a sum of the start time and the buy time duration.

[101] On the screens indicated by reference numerals 2 and 2-1, although a purchase button is pressed, if the mobile terminal is in a MIN number initialization state or in a non-registration state, the procedure does not proceed to the next step, and a popup window saying You can apply after registration of the mobile terminal, without an OK button is opened.

[102] When a preview has expired during viewing, the last reproduction image is displayed as a still image. When the mobile terminal shifts to a channel after a preview has expired, a loading screen of the channel is displayed.

[103] When a buy time has been exceeded, it is impossible to make a purchase, and the channel is shifted to a previous viewing channel (see reference numeral 2-2).

[104] When a result of a query about if there is callback data corresponds to CAS

message #E358, it is impossible to make a purchase. When a transmission has failed, an attempt for the transmission is again made up to three times. When a callback has been completed at the third attempt during the attempts for the transmission, TU is resumed at the next step.

[105] Referring to FIG. 10, when there is no IPPV purchase history, a coverage and a battery are checked, it is checked if a CAS PIN has been locked, an authentication is performed by inputting a PIN, and the user contacts customer service when a debit limit has been exceeded, i.e. upon no credit, (see reference numerals 4 and 5).

[106] Referring to FIG. 11, when an authentication has been made before a buy time hh:mm, and a purchase of broadcast data has been completed within a debit limit, it is checked if there is an IPPV purchase history upon termination of the TU, and the IPPV purchase history is transmitted when the IPPV purchase history exists.

[107] As shown in FIG. 12, after a purchase, it is possible to cancel the purchase by clicking a purchase cancellation button and inputting a TU password until a predetermined time hh:mm (which is shown up to the minute unit). After a purchase, if the user is continuously viewing a PPV channel or if the channel shifts to another channel and then to the PPV channel, a purchase cancellation menu is displayed only until a purchase-cancelable time has expired. Even after the purchase-cancelable time has expired, the purchase cancellation menu may be displayed. In this case, when the purchase cancellation menu is selected, a popup window saying It is impossible to cancel the purchase, is opened.

[108] The purchase cancellation menu is implemented in such a manner as to add a purchase cancellation function to a sub-menu when the sub-menu exists in a menu key, or as to display a banner indicated by reference numeral 8 during a purchase- cancelable time when a menu key is used only for display of a mini-EPG. When the purchase cancellation function is displayed as a sub-menu, no separate banner is displayed on the screen.

[109] A period of time for which the purchase cancellation banner or the purchase cancellation menu is displayed and operated is based on a Ctime value returned through a client library upon PPV purchase.

[110] According to an exemplary embodiment of the present invention, the purchase cancellation function may be set to be displayed/operated only when the returned Ctime value exceeds zero, and not to be displayed when the returned Ctime value is zero. Otherwise, the purchase cancellation function may be set to be displayed/operated only when the returned Ctime value is zero. Also, it is possible to display a popup window saying It is impossible to cancel the purchase, when the menu is selected. When a purchase is to be canceled in a state where a PPV purchase history has not been called back, neither PPV purchase history nor a purchase cancellation history is called back.

When a purchase is to be canceled in a state where a PPV purchase history has been called back, a purchase cancellation history is called back.

[I l l] Information about the purchase-cancelable time is included in an entitlement control message (ECM), and is transmitted from the CAS to the digital broadcast receiving terminal. According to an implementation scheme, the information about the purchase-cancelable time may be included in a PSI/SI table, instead of the ECM, so as to be transmitted according to implementation schemes.

[112] When the purchase cancellation function operates by the CAS, and information about the purchase-cancelable time is included in ECM information of the CAS, the information about the purchase-cancelable time is included in a response message. When the purchase-cancelable time is zero, it represents that it is impossible to cancel a purchase. In this case, the screen of the purchaser s terminal displays The purchase cannot be canceled when the user selects cancellation, or the screen does not display a purchase cancellation menu/function from the very first.

[113] According to the policy of each service provider, it is set that purchase cancellation is possible X times (wherein X is an integer equal to or greater than one).

[114] When the purchase cancellation function operates by separate PSI/SI information, a buy time and a purchase-cancelable time of the terminal are calculated, and the user interface (UI) of the terminal is controlled.

[115] The purchase cancellation history is stored and called back, wherein the purchase cancellation history is stored in a memory of the terminal or an SMD card, similar to the purchase history. Even when the purchase history has already been called back, the purchase cancellation history must necessarily be called back. When a purchase is canceled in a state where the purchase history has not been called back, it is possible to call back both the purchase history and purchase cancellation history, or it is possible to manage only the terminal without calling back the purchase history and the purchase cancellation history.

[116] The method according to the present invention, as described above, can be realized by a program and can be stored in a recording medium (such as a CD ROM, a RAM, a floppy disk, a hard disk, a magneto-optical disk, etc.) in a format that can be read by a computer.

[117] Meanwhile, as described above, the present invention provides a purchase cancellation function so that it is possible to cancel program contents which have been purchased through a service requesting a fee to be paid for every viewed program, and has been explained with the IPPV service as such a service, which is just one embodiment of the present invention. That is, the present invention may be applied even to a pay-per-view (PPV) service, which requests a fee to be paid for every program viewed through a digital broadcast receiving terminal, like the IPPV service.

Therefore, when the present invention is applied to the PPV service, the same effects as those described above will be obtained even in the PPV service.

[118] Although several preferred embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Industrial Applicability

[119] According to the present invention, there is a provided a purchase cancellation function of canceling a purchase of contents purchased in the IPPV or PPV scheme, which requests a fee to be paid for every program viewed through a digital broadcast receiving terminal. In addition, a purchase history and a purchase cancellation history may be stored in a SIM card of a DMB terminal and may be managed, or the histories may be managed by a callback server.

[120] Accordingly, the present invention has industrial applicability because it has sufficient marketability or business possibility as well as applicability to related services, and is also obviously practicable.

[121]