WO2007129863A1

WO2007129863A1 - Method and system for guaranteeing service continuity in a digital broadcasting system

Info

Publication number: WO2007129863A1
Application number: PCT/KR2007/002274
Authority: WO
Inventors: Yiling Xu; Jae-Yeon Song; Kook-Heui Lee
Original assignee: Samsung Electronics Co., Ltd.
Priority date: 2006-05-09
Filing date: 2007-05-09
Publication date: 2007-11-15
Also published as: EP2016792A1; KR20070109800A; EP2016792A4; KR20070109901A

Abstract

A method for providing service continuity in a home network of a digital broadcasting system. The home network acquires, from a neighboring network, service information for broadcast services provided in the neighboring network. The home network compares the service information acquired from the neighboring network with currently provided service information, and generates service mapping information indicating at least one second broadcast service being similar or identical to a first broadcast service currently provided to a terminal, among broadcast services provided in the neighboring network. The home network transmits the generated service mapping information to the terminal so that the terminal can continuously receive the broadcast service after roaming to the neighboring network.

Description

METHOD AND SYSTEM FOR GUARANTEEING SERVICE CONTINUITY IN A DIGITAL BROADCASTING SYSTEM

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates generally to a digital broadcasting system, and in particular, to a method and system for guaranteeing service continuity of the ongoing service using an Electronic Service Guide (ESG) of Convergence of Broadcasting and Mobile Service (CBMS).

Description of the Related Art

With the recent development of communication and broadcasting technologies, broadcasting systems and/or mobile communication systems provide Mobile Broadcast (BCAST), and discussion is being made on Mobile Broadcast that can transmit packet data as well as the common voice/image- limited broadcast service over a broadcast channel.

Mobile Broadcast can be achieved with a process of discovering a service by a mobile terminal such as mobile phone, notebook computer, Personal Digital Assistant (PDA), etc., capable of receiving Mobile Broadcast, a process of subscribing to the service by the mobile terminal, a process of provisioning a variety of information needed for receiving the service, and a process of transmitting and receiving the service by the mobile terminal.

Open Mobile Alliance (OMA), one of the groups of studying standards for interworking between individual mobile solutions, mainly takes charge of establishing various application standards for games on mobile communication, Internet services, and the like.

Of OMA Working Groups, Sub Working Group of OMA Browser and Content (BAC) Mobile Broadcast (BCAST) is studying and researching technology for converging broadcast services and mobile communication services using mobile terminals capable of communication with interactive networks. Also, Digital Video Broadcasting - Convergence of Broadcasting and Mobile Service (DVB-CBMS), one of Mobile Broadcast terminal standard groups, defines system architecture and interfaces for convergence of the broadcast services and the mobile communication services.

Generally, in the Mobile Broadcast system, a terminal for receiving broadcast services receives a Service Guide (SG) including description information for a service itself, charging information for the service, and information on a reception method of the service, and receives a desired service using the service guide.

In the Mobile Broadcast system, when a terminal moves to another network, i.e. visited network, of a foreign service provider, other than the current network, i.e. home network, of the home service provider to which its user has subscribed, the user may want to receive the broadcast service of the home network or a service of the foreign service provider having a roaming contract with the home network, using his/her terminal. This procedure is called 'roaming'. Also, when the terminal moves from the home network to the visited network in the course of receiving a broadcast service, the user may want to seamlessly receive the broadcast service using the terminal, and this procedure is called 'handover'.

However, the conventional CBMS system provides no specific procedure for the roaming and handover of the broadcast service.

Therefore, there is a need for a technology for efficiently providing the roaming and handover of the broadcast service in the Mobile Broadcast system.

SUMMARY OF THE INVENTION

An aspect of the present invention is to address at least the problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a method and system for guaranteeing service continuity for a terminal in a digital broadcasting system. Another aspect of the present invention is to provide a method and system for exchanging service mapping information between a home network and a neighboring network to guarantee service continuity in a digital broadcasting system.

Another aspect of the present invention is to provide a method and system for generating messages including service content type information and exchanging the messages between a home network and a neighboring network to guarantee service continuity in a digital broadcasting system.

Another aspect of the present invention is to provide a method and system for generating messages including time difference information of a service and exchanging the messages between a home network and a neighboring network to guarantee service continuity in a digital broadcasting system.

According to one aspect of the present invention, there is provided a method for providing service continuity in a home network of a digital broadcasting system. The method includes acquiring, from a neighboring network, service information for broadcast services provided in the neighboring network; comparing the service information acquired from the neighboring network with currently provided service information, and generating service mapping information indicating at least one second broadcast service being similar or identical to a first broadcast service currently provided to a terminal, among broadcast services provided in the neighboring network; and transmitting the generated service mapping information to the terminal so that the terminal can continuously receive the broadcast service after roaming to the neighboring network.

According to another aspect of the present invention, there is provided a method for receiving service continuity from a neighboring network by a terminal in a digital broadcasting system. The method includes determining whether there is a need for roaming; if it is determined that there is a need for roaming, issuing a request for service mapping information indicating at least one second broadcast service being identical or similar to a first broadcast service currently received from a home network, among broadcast services provided in at least one neighboring network; and upon receipt of a service mapping information response message with service mapping information from the home network, continuously receiving the second broadcast service in succession to the first broadcast service from a selected one of at least one neighboring network using the service mapping information.

According to further another aspect of the present invention, there is provided a digital broadcasting system for providing service continuity to a terminal. The digital broadcasting system includes a home network for acquiring, from a neighboring network, service information for broadcast services provided in the neighboring network, comparing the acquired service information with service information for broadcast services provided in the home network, generating service mapping information indicating at least one second broadcast service being similar or identical to a first broadcast service currently provided to the terminal, among broadcast services provided in the neighboring network, and transmitting the generated service mapping information to the terminal; and the terminal for receiving the service mapping information, and continuously receiving the second broadcast service in succession to the first broadcast service from a selected one of at least one neighboring network using the service mapping information.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, 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:

FIG. 1 is a block diagram illustrating architecture of a CBMS system according to a preferred embodiment of the present invention;

FIG. 2 is a diagram illustrating a data model of an ESG according to a preferred embodiment of the present invention;

FIG. 3 is a diagram illustrating a roaming procedure without service continuity guaranteed according to the present invention;

FIG. 4 is a diagram illustrating a roaming procedure with service continuity guaranteed according to the present invention; FIGs. 5 to 7 are diagrams illustrating three types of a time difference; FIG. 8 is a diagram illustrating a signaling procedure of a terminal according to the present invention;

FIG. 9 is a diagram illustrating a roaming procedure of a home network according to a first embodiment of the present invention; FIG. 10 is a diagram illustrating a roaming procedure of a home network according to a second embodiment of the present invention;

FIGs. HA and HB are diagrams illustrating signaling flows of roaming messages with service continuity guaranteed according to the first and second embodiments of the present invention; FIG. 12 is a diagram illustrating architecture of a home network according to the first and second embodiments of the present invention; and

FIG. 13 is a diagram illustrating architecture of a terminal according to the first and second embodiments of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will now be described in detail with reference to the annexed drawings. In the following description, a detailed description of known functions and configurations incorporated herein has been omitted for clarity and conciseness.

The present invention provides a method and system for seamlessly receiving the current ongoing service when a subscriber of a home service provider, i.e. a receiver or terminal, moves from a service area of a home network of the home service provider to a service area of another network of a foreign service provider in a Convergence of Broadcasting and Mobile Service (CBMS) system.

The present invention is characterized in that information on supportable services is exchanged between the home network and another network, and the home network generates service mapping information for mapping the services supportable by another network to its own services, and provides the generated service mapping information to terminals so as to support a roaming service of the terminals. FIG. 1 illustrates architecture of a CBMS system according to a preferred embodiment of the present invention. Shown are logical entities for accomplishing the functions required for Digital Video Broadcasting - Handheld (DVB-H)-based Internet Protocol Data Cast (IPDC). The shown entities are divided according to difference of the major functions, and can be located in the physically divided servers or the same server.

Referring to FIG. 1, a Content Creation block (CC) 110 generates content sources of a broadcast service and sends the content sources to a Service Application block (SA) 120.

The Service Application block 120 generates service data for a particular service by aggregating the content sources provided from the Content Creation block 110 and the metadata additionally required for service configuration. To this end, the Service Application block 120 is made up of several sub-entities that manage different applications for their associated services.

A Service Management block (SM) 115 perform functions of service configuration, resource allocation, Electronic Service Guide (ESG) provisioning, security, etc. between the Service Application block 120 and a Terminal 160.

A Broadcast Network 140, a network for transmitting broadcast service data, can be, for example, a DVB-H system.

An Interactive Network 150 generally means a cellular mobile communication network such as a 3^rd Generation Partnership Project (3GPP)- based Universal Mobile Telecommunications System (UMTS) network, a 3GPP2- based International Mobile Telecommunications (IMT)-2000 network, and a Wireless Broadband internet (WiBro) network. As another example, the Interactive Network 150 can be all kinds of mobile communication networks that provide a function capable of receiving information or request transmitted from the Terminal 160 and sending a response to the information or request.

The Broadcast Network 140 and the Interactive Network 150 act as transmission bearers in the CBMS system. The Terminal 160 means a user terminal, and indicates a receiver capable of accessing the Interactive Network 150 and receiving a broadcast service from the Broadcast Network 140.

In the CBMS system, the Terminal 160 receives service data and signaling information from the Broadcast Network 140, and interactively exchanges the service data and the signaling information with the Interactive Network 150.

A description will now be made of interfaces between entities including the logical entities described above.

X-I, X-2 and X-3 interfaces mean reference points between the Broadcast Network 140 and other entities, and are generally not used in the DVB-H based interactive standard. The X-I interface makes a connection between Content Creation block 110 and the Service Application block 120, the X-2 interface makes a connection between the Interactive Network 150 and the Terminal 160, and the X-3 interface makes a connection between the Service Management block 115 and the Interactive Network 150.

A CBMS-I interface conveys broadcast-related signaling, and a CBMS-2 interface conveys contents such as audio, video, file, and the like. A CBMS-3 interface conveys an Electronic Service Guide (ESG), a CBMS-4 interface conveys an ESG in a Point-to-Point (PtP) transmission manner, and a CBMS-5 interface conveys Short Message Service (SMS), Multimedia Message Service (MMS), etc. in a PtP transmission manner. A CBMS-6 interface conveys configuration parameters such as the number of services, allocated bandwidth, etc. for DVB-H transmission, and a CBMS-7 interface conveys a declaration or metadata of a service application. Although the foregoing description has been made of the typical functions of the interfaces, by way of example, it is not intended to limit the functions of the interfaces to the above description.

FIG. 2 illustrates a data model of an ESG according to a preferred embodiment of the present invention.

Referring to FIG. 2, shown blocks indicate fragments of ESG data. That is, the ESG data model includes a Service fragment 202, a Schedule Event fragment 204, a Content fragment 206, an Acquisition fragment 208, a Service Bundle fragment 210, a Purchase fragment 212, and a Purchase Channel fragment 214.

The Service fragment 202 includes a full description of services, the

Schedule Event fragment 204 indicates time information of the services, and the Acquisition fragment 208 includes service access information that the terminal needs to acquire to receive service data. The Service Bundle fragment 210 includes information for the case where several services are packed up into one service bundle, the Purchase fragment 212 provides price information for purchase of the service bundle, and the Purchase Channel fragment 214 provides information on the system needed to be used for acquiring a right for the purchase.

Each of the fragments of the data model can make reference to other fragments, and arrows between the fragments indicate the reference relationship.

The 'reference' as used herein refers to an operation in which the current fragment provides information related to its own fragment using information transmitted from another fragment. That is, when one service is composed of several contents, the Service fragment 202 merely includes a full description of a service, for example, name and language of the service, but does not include a description of the contents transmitted through the service. However, the Content fragment 206 of the corresponding contents makes reference to the Service fragment 202. In order to acquire a variety of information necessary for receiving the service, for example, session information used for a transmission protocol, the terminal should receive the Acquisition fragment 208 to which the Service fragment 202 makes reference, and demodulate the received Acquisition fragment

208.

The ESG data is separately transmitted to the terminal at a different time from that of a data stream, using at least one IP stream. Therefore, with use of the

ESG data model, the service provider, before transmission of the service, can provide the information that the user should acquire before receiving the service.

By receiving an ESG stream, the terminal acquires the information necessary for receiving the services provided by the service provider, and when the user selects a particular service, the terminal accesses the data stream over which the service is transmitted, using the acquired information, and then receives data. The information that the terminal needs in accessing the service data stream is transmitted through the Acquisition fragment 208 as described above.

The ESG data models are contained in one container after they are bundled for each individual fragment, and each container is regarded as one object in a File Delivery over Unidirectional Transport protocol (FLUTE) session during its transmission.

In the CBMS system, when there is a need for handover, different handover types based on different conditions are used. For example, one of passive handover and active handover can be used according to availability of an interactive channel. Here, one of signaling delivery over an interactive channel and service delivery over an interactive channel is used according to whether the data transmiτtable over the interactive channel is signaling information or service data. In addition, one of network-controlled handover and terminal-controlled handover can be used according to whether an entity for making handover decision is a network or a terminal.

Because the terminal cannot immediately recognize the full handover procedure without previous condition information, the terminal needs to communicate with the network in order to acquire information related to the handover type (hereinafter referred to as 'handover information'). Therefore, a preferred embodiment of the present invention adds the handover information to an ESG related to the broadcast service. The terminal, before the handover actually occurs, acquires the handover information from the ESG and appropriately determines a needed handover time and a handover type based on other condition information acquired from the ESG.

For example, the handover information according to a preferred embodiment of the present invention is added as a new information element to at least one of the Service fragment 202, the Content fragment 206 and the Acquisition fragment 208 described in FIG. 2, or added in an ESG as a new fragment (for example, a handover fragment). In this context, in the current mobile communication system, although there is no specific definition of the concept of handover and roaming, it is expected that the handover and roaming will change according to a change in IP platform, ESG provider and network operator.

In this connection, the present invention provides a scheme of performing handover and roaming on the assumption of a change in IP platform. Also, the present invention can be modified and applied according to other definitions such as a change in ESG provider and a change in network operator.

The term 'roaming' used in this specification is given as an example, and can be changed to handover or other terms according to the final definition. In present invention, 'roaming' and 'handover' refer to the same procedure, and although the term 'roaming' out of the two terms will be used in this specification, by way of example, it can be replaced with the term 'handover' and can also be replaced with other term according to the final definition. Further, although the 'roaming' procedure according to a change in IP platform will be described herein, by way of example, a roaming procedure according to a change in ESG provider and/or a change in network operator is also possible. Of the terms used in the present invention, 'another (or foreign) network' means all networks except for the home network, 'neighboring network' means networks neighboring the home network, and 'candidate network' means a network providing the similar or same broadcast service as the broadcast service provided by the home network, among the neighboring networks, i.e. means one of the neighboring networks. To be specific, the candidate network is a target network to which the terminal will perform roaming.

FIG. 3 illustrates a roaming procedure without service continuity guaranteed according to the present invention.

Referring to FIG. 3, a terminal receives a service from a home network (IP platform, ESG provider) in step 311, and views an ESG of a neighboring network in step 312. Thereafter, the terminal receives a service from another network (IP platform, ESG provider) in step 313. As described above, the terminal can tune (turn) to another IP platform when a consuming service is not available in one IP platform (ESG provider, network provider, etc) and when the terminal still wants to consume the corresponding service. This procedure is called 'roaming'.

However, according to the current general roaming procedure, the terminal, as in step 312, should interrupt the reception of the service provided from the current home network for a time tl ~ t2, in order to receive an ESG of neighboring network and determine presence/absence of a desired service. If the desired service exists in another network, the terminal can turn to another network to receive the corresponding desired service. However, because the service reception should restart after the current service first terminates, the roaming procedure of FIG. 3 cannot support service continuity of the terminal.

In this context, a roaming procedure with service continuity guaranteed according to the present invention will be described with reference to FIG. 7.

For example, if the identical service exists in further another IP platform, the terminal searches for (finds) candidates while continuously receiving the service from the current IP platform, and can receive the identical service from further another IP platform stated above. That is, the roaming with service continuity guaranteed can be supported. Here, a service identifier (Service ID, IP address) is allocated only within a specific scope (one ESG provider, IP platform, network, etc). When the terminal intends to leave the current scope and keep the current consuming service, a method proposed in the present invention can be used. When the terminal intends to keep the service but to change the reception from another scope (for example, IP platform, provider, network, etc.), the terminal intends to apply the present invention.

For a description of the concept of service continuity, the following two factors should be taken into account.

Of the two factors, one is continuity of service content and another is time difference. When the service content concept is taken into consideration, service contents from two different IP platforms (or ESG providers) can be classified into three types as shown in Table 1.

TABLE l

Also, service continuity based on the time difference can be classified into three types as shown in Table 2.

TABLE 2

FIGs. 4 to 6 illustrate three types of the time difference. FIG. 4 shows the time difference type = Type 1 'identical', in which there is no time difference between Service A provided from IP platforms (or ESG providers) of the home network and Service A' provided from IP platforms (or ESG providers) of another network.

In this case, the terminal, after its roaming to another network, can seamlessly receive even in another network the service that it was receiving in the home network.

FIG. 5 shows the time difference type = Type 2 'ahead', in which Service A' provided from IP platforms (or ESG providers) of another network is serviced ahead of Service A provided from IP platforms (or ESG providers) of the home network, by delta T.

FIG. 6 shows the time difference type = Type 3 'behind', in which Service A provided from IP platforms (or ESG providers) of the home network is serviced behind Service A' provided from IP platforms (or ESG providers) of another network, by delta T.

When the service of the neighboring network goes ahead of or goes behind the service of the home network, i.e. when their service times are different from each other, the terminal cannot continuously receive the service. In this case, before moving to neighboring networks, receiving ESGs therefrom and checking the contents of the received ESGs one by one, the terminal notifies the user that the service being identical or similar to the service previously received from the home network is received from the neighboring network, thereby allowing the user to recognize that he/she can receive from the neighboring network the service that he/she was previously receiving from the home network.

Therefore, in an embodiment of the present invention, the home network provides the time information of Table 2 to the terminal, and the time information can be used for scheduling the services provided from the foreign (or external) network. Therefore, with use of the time information, the terminal can schedule service provision to the user. For example, when the service being identical or similar to the service provided in the home network is provided in the neighboring network four hours later, the terminal can instruct the user to access the neighboring network and receive the service four hours later.

The service mapping information that the home network has generated taking the foregoing factors into account can be summarized as shown in Table 3. In addition, the terminal can receive the service after compensating for the time difference between the service provided in the home network and the service provided in the neighboring network using the time difference information between the home network and the neighboring network.

TABLE 3

That is, the service mapping information according to an embodiment of the present invention, shown in Table 3, includes service identifier information such as service identifiers (Service IDs) of the services provided from the home network and the neighboring network, IP addresses of the home network and the neighboring network, ESG provider IDs of the home network and the neighboring network, and IP platform IDs of the home network and the neighboring network; content type information indicating identity between the broadcast services provided from the home network and the neighboring network; time difference information between the services provided from the home network and the neighboring network; and access information with which the terminal accesses the neighboring network.

Of the information, the service identifier information is information that should necessarily be included in the service mapping information, and the other information of 'content type', 'time difference and/or schedule' and 'access information' can be included on a scenario by scenario basis, or only a part of it can be included.

Herein, Service A indicates a service of the home network (IP platform, ESG provider), and Service A' indicates a mapping service of the foreign network (IP platform, ESG provider). The 'mapping service' refers to a service provided from another network, IP platform or ESG provider, which is similar or identical to the service provided from the home network.

The service mapping information is information related to the service provided from another network, IP platform or ESG provider, which is similar or identical to the service provided from the current home network, and this is as shown Table 3.

Herein, Service A is one service provided from the current IP platform (ESG provider, network), and Service A' is a service provided from another IP platform (ESG provider, network), which is similar or identical to Service A provided from the current IP platform (ESG provider, network). Therefore, Service A' is a mapping service of Service A.

The service mapping information between Service A and Service A' is as shown in Table 3, in which service identifier information (Service ID, IP address, ESG provider ID, IP platform ID), content type, time difference and/or schedule information, and access information are included.

The access information includes corresponding frequency, transmission stream, cell, network information, etc., and can help the terminal search for a desired service.

As described above, it can be noted that for the service continuity issue, there are different types. Actually, the provided type information differs according to conditions. It will be assumed herein that there are two possible cases in which the terminal needs roaming.

Case l

For example, when a certain user consumes a certain service while moving to the service area boundary of the current service, it needs roaming.

However, the user may want to use the current service without interruption. In this case, the requirement for the time is very high, and what the user wants is a non-time difference type service. Therefore, the terminal needs only the information on the candidate service with no time difference (time difference = O).

Case 2

In another case, when a user frequently travels between different countries (for example, this may often happen in the European communication environment), roaming occurs. At this time, the user, although he/she does not want to consume the completely identical service without any interruption, may want to know whether the similar or identical service to the service in the home network (IP platform, ESG provider) and its associated information are available even in another network (IP platform, ESG provider).

This is because the user usually wants to consume his/her familiar service

(or some regular service) even though he/she leaves the home network. If such information exists in the ESG of the network to which the terminal has moved, the user should acquire the corresponding information by parsing the ESG of the network to which the terminal has moved.

If the corresponding service mapping information can be provided in the home network, the following advantages can be provided. First, the user has no need to wait until he/she arrives at the foreign network, and after receiving the foreign ESG, the user can previously acquire this information and make a plan according to the information. If the service mapping information is not provided from the home network, the user can acquire the service information only after accessing another network and parsing only the foreign ESG. Because mapping of the service information is already provided in the home network, the user can acquire the identical or similar service information without viewing the foreign ESG when there is a change in reception from the foreign network.

Second, a procedure for parsing the foreign ESG can be stored.

For the above information in the ESG of the home network, even though the terminal moves to the foreign network, the terminal can prepare an operation for receiving the services being identical or similar to the services provided in the home network. Otherwise, it is almost impossible for the terminal to recognize the identical service by simply viewing the ESG of another network, because even for the identical service, service ID and other service-related information are different for each ESG.

For example, if the user goes abroad and the ESG is made in a foreign language, the terminal may have difficulty in finding the desired service.

Therefore, if the user is previously provided with the relevant service information shown in Table 4 and Table 5, it will benefit the user. The service information, the entire information related to the service, is herein the information necessary for generating the service mapping information.

A format of the service mapping information is variable. Table 4 shows a type of a service mapping information format, and Table 5 shows another type of the service mapping information format.

In Table 4, the service mapping information is provided on a service by service basis. For example, if there are two types of services, Table 4 first lists service mapping information for Service 1, and then lists all the service mapping information for Service 2.

In Table 5, the service mapping information is provided by content type. For example, first, the service mapping information for all identical services is listed. Second, the service mapping information for all variation services is listed. Finally, all related services are listed. If one terminal considers only the identical service in another IP platform, it can make the search only in the first section in Table 5.

TABLE 4

TABLE 5

With use of the service mapping information of Table 4 and Table 5, the user can fast and easily find its desired service. Therefore, this benefits the user in terms of service. Also, because service continuity is supported with such information, it will attract more users to consume the service, benefiting the service operators. In addition, the service mapping information can be provided in various ways according to conditions.

A description of the service mapping information has been made so far. A description will now be made of several possible variations in the service mapping information according to different scenarios and uses.

Case 1 and Case 2 have been given above. In Case 1, when there is a change in broadcast service reception from another IP platform (ESG provider, network), all the service mapping information is provided to support service continuity. In Case 2, only service identifier and content type other than the service mapping information may be provided.

In a first use case, what the terminal requires is to continuously receive the current service without interruption when there is a change in the service reception from another ESG provider and IP platform. Therefore, service identification information (Service ID, IP address, ESG provider ID, IP platform

ID), content type, time difference, and access information, all of which are service mapping information, are required, and with use of the service mapping information, the terminal has already found the candidate network and access information of the candidate network, and can transition to a reception state.

In a second use case, the service identifier mapping information and the content type are required to help the terminal determine whether the identical or similar service exists in another ESG provider and IP platform.

In the second use case, the terminal determines whether the similar or identical service path exits in another ESG provider and IP platform, depending on the service identifier mapping information and content type.

If other mapping information for the time difference and the access information is also provided, the terminal can change the new ESG reception without user browsing.

However, if no other mapping information for the time difference and the access information is provided, the user finds a new ESG, and finds a schedule related to the access information using its mapping identifier of the mapping information.

Therefore, the present invention includes providing mapping information between services provided from different IP platforms (ESG providers or network operators), to the terminals. In particular, the present invention provides a scheme in which the home network generates service mapping information using service information collected from other networks and provides the service mapping information via an interactive network. FIG. 7 illustrates a roaming procedure with service continuity guaranteed according to the present invention.

Referring to FIG. 7, in step 711, a terminal detects a need for a roaming process at a time tl while continuously receiving a service from a home network (IP platform, ESG provider). In step 712, the terminal requests and collects mapping information of the service being received from the current home network over an interactive network. For roaming with service continuity guaranteed, the terminal searches for neighboring networks that provide the similar or identical service to the service provided from the home network, among the neighboring networks. The terminal selects the highest-signal strength neighboring network among the searched neighboring networks, as a candidate network. In step 713, the terminal turns its operation to receive the similar or identical broadcast service to the broadcast service received from the home network, from the candidate network selected in step 712, and receives the broadcast service from the candidate network (IP platform, ESG provider). Therefore, the terminal can support service continuity even though it performs roaming from the home network to the candidate network.

That is, if the same service exists in further another IP platform (ESG provider, network), it is possible to enable service continuity for the terminal by providing particular information.

In this context, the present invention proposes mapping information indicating the relationship and access parameter for the identical service provided from different IP platforms (or providers, networks). The service mapping information can be added to a Program Specific Information/System Information (PSI/SI) or ESG. Also, the service mapping information can be transmitted over the interactive channel.

A detailed description will now be made of a corresponding procedure of each network node, a message flow, and a message format.

FIG. 8 illustrates a signaling procedure of a terminal according to the present invention. Referring to FIG. 8, a terminal receives a service from a home network in step 800. Upon detecting a need for roaming in step 805, the terminal sends a service mapping information request message to the home network in step 810. The terminal receives a service mapping information response message from the home network in step 812. The terminal parses the received service mapping information response message in step 814 to determine whether service mapping information included in the service mapping information response message is available. Although formats of service mapping information request and response messages exchanged over the interactive network have not been defined in detail herein, the major contents of the request and response messages are shown in Table 6 and Table 7. That is, the service mapping information will be transmitted in the formats shown in Table 6 and Table 7, when the terminal inquires whether there is service mapping information for the instant the terminal moves to a specific network for a specific network, and then sends a response to the inquiry.

If it is determined in step 814 that service mapping information is available, the terminal tests in step 816 its neighboring networks to select therefrom a candidate network that provides a similar or identical service to the service provided from the home network, and has the highest received signal strength. After selecting the candidate network for roaming in step 816, the terminal performs in step 818 roaming to the selected candidate network and receives the service therefrom.

However, if it is determined in step 814 that there is no available information in the service mapping information, the terminal proceeds to step 820 where it performs an operation corresponding to a predetermined procedure. The operation performed in step 820 is variable, and can include, for example, an operation of terminating service consumption or turning to another service, and a detailed description thereof will be omitted herein, because it departs from the scope of the present invention.

As described above, in an embodiment of the present invention, the terminal sends a service mapping information request to the home network if there is a need for roaming. Herein, the request by the terminal may include information indicating a type of the acceptable roaming service, information indicating whether the corresponding service is an 'identical', 'variation' or 'associated' service, information indicating requirement for the service difference, information indicating the schedule, and information indicating whether access information is needed. After receiving a service mapping information response from the home network, the terminal determines whether the requested service mapping information is available, and continually receives the service according to the result.

FIGs. 9 and 10 illustrate a roaming procedure of a home network according to an embodiment of the present invention. The roaming procedure can be divided herein into two different embodiments according to agreement between the home network and the foreign network.

Specifically, FIG. 9 illustrates a roaming procedure of a home network according to a first embodiment of the present invention, and FIG. 10 illustrates a roaming procedure of a home network according to a second embodiment of the present invention. The two embodiments can be distinguished according to whether the home network will send a request for service information to neighboring networks before a roaming request of the terminal, or will send the request after the roaming request.

In the shown roaming procedure of the home network according to the first embodiment of the present invention, the home network previously acquires service information from neighboring networks, generates and stores service mapping information using the acquired service information, and sends a service mapping information response message with the generated service mapping information upon receipt of a service mapping information request message from the terminal.

Referring to FIG. 9, the home network receives service information from a neighboring network and updates the service information in step 900. The home network generates in step 902 service mapping information using the service information acquired in step 900 and updates the previously stored service mapping information with the generated service mapping information. Here, in step 900, the home network sends a request for service information to the neighboring network and receives a response to the sendee information request from the neighboring network. In step 904, the home network receives a service mapping information request message from the terminal. After receiving the service mapping information request message from the terminal in step 904, the home network sends a service mapping information response message with the service mapping information generated in step 902 to the terminal in step 906.

As described above, in the first embodiment, the home network and the neighboring network update service mapping information by communicating service information. This means that the home network has already stored the service mapping information. Therefore, upon receiving the service mapping information request message from the terminal, the home network can immediately send a service mapping information response message to the terminal according to terminal requirement and service mapping information collected from neighboring networks .

FIG. 10 illustrates a roaming procedure of a home network according to the second embodiment of the present invention. Referring to FIG. 10, the home network receives a service mapping information request message from a terminal in step 1000. The home network sends a request for service information to neighboring networks in step 1002. The home network receives service information responses from the neighboring networks in step 1004. The home network generates in step 1006 service mapping information using the service information received from the neighboring networks, and sends in step 1008 a service mapping information response message with the generated service mapping information to the terminal.

As described above, in the second embodiment, the home network and the neighboring network do not previously communicate (exchange) service information. Therefore, upon receiving a service mapping information request from the terminal, the home network sends a service information request to neighboring networks. If the home network receives a service information response from at least one of the neighboring networks, it sends the result to the terminal. FIGs. HA and HB illustrate signaling flows of roaming messages with service continuity guaranteed according to the first and second embodiments of the present invention. In FIGs. HA and HB, steps 1106 to 1122 show a signaling flow according to the first embodiment of the present invention, and steps 1138 to 1156 show a signaling flow according to the second embodiment of the present invention. Referring to FIGs. HA and HB, reference numeral 1100 denotes a terminal, reference numeral 1102 denotes a home network, and reference numeral 1104 denotes a neighboring network of the home network 1102. The entities in the home network 1102 will be described in detail with reference to FIG. 12.

According to the first embodiment, the terminal 1100 is receiving a service from the home network 1102 in step 1106. At this time, the neighboring network 1104 is providing the identical or similar service to the service that the terminal 1100 is currently receiving from the home network 1102, i.e. is a candidate network. In this context, the terminal 1100 intends to perform roaming to the neighboring network 1104 so as to guarantee service continuity.

In step 1108, the home network 1102 acquires service information from the neighboring network 1104. That is, the service information can be communicated between the home network 1102 and the neighboring network 1104 to which the terminal 1100 will perform roaming. The home network 1102 can periodically acquire service information from the neighboring network 1104, or can acquire the service information by sending a request for the service information to the neighboring network 1104.

If the terminal 1100 determines in step 1107 that there is a need for roaming to a neighboring network, the terminal 1100 sends a service mapping information request message to the home network 1102 via an Interactive Network 1102c in step 1110. In step 1112, the Interactive Network 1102c sends over an interactive channel the service mapping information request to a Mobility Management (MM) block in an SM block 1102b that manages mobility, handover and roaming of the terminal.

Upon receiving the service mapping information request message from the terminal 1100 in step 1112, the SM 1102b generates in step 1113 service mapping information using service information from the neighboring network 1104, acquired in step 1108. Here, the SM 1102b in the home network 1102 generates service mapping information, shown in Table 3, indicating at least one of the similar or identical services to the service that the terminal 1100 desires to receive, among the broadcast service currently provided from the home network 1102 to the terminal 1100 and the broadcast services provided from the neighboring network 1104.

The SM 1102b can generate the service mapping information immediately upon acquiring the service information from the neighboring network 1104 in step 1108, or can generate the service mapping information when the service mapping information request message is received from the terminal

1100 in step 1112. The service mapping information generated in step 1108 immediately after receiving the service information from the neighboring network will be the mapping information for the services from all neighboring networks of the home network 1102, and if the service mapping information is service mapping information generated in step 1113 immediately after receiving the service mapping information request message from the terminal 1100, the service mapping information corresponding to the neighboring network to which the terminal 1100 will perform roaming will be included therein.

That is, the service mapping information request is service mapping information for one service, and this is sent to the MM block in the home network 1102. In other words, the service mapping information request message sent by the terminal is sent to the MM block in the home network. AU MM blocks are identical in structure, but the MM blocks in the home network and the foreign network will be different in detailed information (i.e. information of the services provided from neighboring networks of the home network).

In step 1114, the MM block in the SM block 1102b sends a service mapping information response message for the terminal 1100 to the Interactive Network 1102c. Then, the service mapping information response message with service mapping information for one service will be sent to the terminal 1100 via the Interactive Network 1102c. In step 1116, the Interactive Network 1102c sends the service mapping information response message to the terminal 1100 over the interactive channel. The home network 1102 can transmit the service mapping information via the Interactive Network 1102c, or can transmit the service mapping information to the Broadcast Network 1102d after including it in an ESG or PSI/SI.

In step 1118, the terminal 1100 makes a test on neighboring networks, and selects one neighboring network providing the best service, among the tested neighboring networks. The selected neighboring network is a candidate network to which the terminal 1100 will perform roaming. The test made herein can be a process of searching for a neighboring network having the highest signal strength and selecting the highest-strength neighboring network. The terminal 1100 performs in step 1120 roaming to the neighboring network selected in step 1118, and receives in step 1122 the broadcast service from the selected neighboring network.

If the home network 1102 has issued a request for service mapping information before receiving a service request message from the terminal 1100, because the generated service mapping information includes all neighboring networks of the home network 1102 and all services provided from the neighboring networks, the terminal 1100 should select in step 1118 not only the neighboring network to which it will perform roaming, but also the service that it will receive, for the following reason. That is, because the service mapping information from the terminal 1100 was generated without the information on the neighboring network to which the terminal 1100 desires to perform roaming, the home network 1102 has generated service mapping information for all neighboring networks and transmitted the generated service mapping information to the terminal 1100.

The operation in which the terminal 1100 seamlessly provides a service while performing roaming according to the first embodiment of the present invention has been described through steps 1106 to 1122. A description will now be made of a process in which the home network 1102c provides service mapping information to the terminal 1100 according to the second embodiment of the present invention. The terminal 1100 is receiving a broadcast service from the home network 1102 in step 1138, and determines in step 1139 whether there is a need for roaming. If there is a need for roaming in step 1139, the terminal 1100 sends a service mapping information request message to the home network 1102 via the Interactive Network 1102c in step 1140. Upon receiving the service mapping information request message over an interactive channel, the Interactive Network 1102c sends in step 1142 the received service mapping information request message to the MM block in the home network 1102, which manages mobility, handover and roaming of the terminal 1100.

Upon receiving the service mapping information request message from the terminal 1100, the MM block in the home network 1102 sends in step 1144 a request for service information to the neighboring network 1104. In step 1146, the MM block in the home network 1102 receives from the neighboring network 1104 a service information response in response to the service information request sent in step 1144. In step 1147, the MM block in the SM 1102b generates service mapping information using the service information response received from the neighboring network 1104 and its own service information.

In step 1148, the MM block in the home network 1102 sends a service mapping information response message with the service mapping information generated in step 1147 to the Interactive Network 1102c. In step 1150, the Interactive Network 1102c sends the received service mapping information response message to the terminal 1100 over an interactive channel.

In step 1152, the terminal 1100 makes a test on neighboring networks, and selects one neighboring network (i.e. candidate network) providing the best service, among the tested neighboring networks. The terminal 1100 performs in step 1154 roaming to the neighboring network selected in step 1152, and receives in step 1156 a service from the neighboring network to which it has performed roaming.

Definitions of the messages used in each step, described in FIGs. HA and

HB, will now be given. That is, a description will now be made of logical messages for roaming with service continuity guaranteed according to the present invention.

The service mapping information request message is a request message for more than one interested services of the terminal, and the terminal may have more than one interested services. In this case, the terminal may want to acquire the mapping information only for the requested services. The terminal does not care whether there is any other mapping service.

Therefore, the home network can define the service mapping information request message by defining a format in which the home network filters the mapping information only for the services requested by the terminal and feeds back the mapping information.

Table 6 shows a format of the service mapping information request message.

The service mapping information request message is send from the terminal to the SM over the interactive network.

TABLE 6

When the terminal requests all mapping service information for more than one foreign networks (IP platform, ESG provider), i.e. when the terminal intends to find all available mapping services existing in more than one foreign networks, the networks search for all the requested service mapping information and feed back the results to the terminal.

Here, the service mapping information request message is represented as service mapping information request message type 2, and can be shown in Table 7.

TABLE 7

Name Description

With use of the service mapping information request type-1 message of Table 6, the terminal can request service mapping information for Service 1. If the service mapping information for Service 1 is available, the home network will provide all service mapping information for Service 1 along with the service mapping information response message.

However, with use of the service mapping information request type-2 message of Table 7, the terminal requests all service mapping information between different IP platforms, i.e. between IP platform 1 and IP platform 2, and if there is all service mapping information for two services provided from IP platform 1 and IP platform 2, the home network transmits the service mapping information for Service 1 and Service 2 along with the service mapping information response message.

Table 8 shows a service mapping information response message.

The content carried in service mappping information response message has been describe above. The detailed service mapping information response message format could be has some options.

For example,the service mapping information response message can be configured herein service by service, type by type, or scope by scope.

A description will first be made of a method of configuring mapping information on a service-by-service basis.

Service-by-Service Configuration: To list all mapping service candidates one by one, the mapping information can be configured as shown in Table 8.

TABLE 8

A format of the service mapping information response message is shown in Table 9. Corresponding frequency, transmission stream, cell, and network information except for the mapping information are provided so that the terminal can find the desired service more easily.

TABLE 9

A description will now be made of a method of configuring mapping information on a type-by-type basis.

Type-by- Type Configuration: Mapping services can be classified according to content type, and mapping information can be configured in the manner of Table 10.

TABLE 10

A format of the service mapping information response message is shown in Table 11.

TABLE 11

Table 9 and Table 11 are different from each other only in inclusion/non- inclusion of Contentype. In other words, Table 9 does not include Contentype, but Table 11 includes Contentype. In addition, Table 9, Table 11 and Table 13 can be regarded as a single message format, and they are generated on a service by service basis (FIG. 8), on a type by type basis (FIG. 10), and on a scope by scope basis (FIG. 12), respectively.

Finally, a description will be made of a method of configuring mapping information on a scope-by-scope basis.

Scope-by- Scope Configuration: Mapping services are classified according to different scopes, and the scopes can be based on different networks (IP platforms, ESG providers).

Therefore, the mapping information based on IP platform can be configured as shown in Table 12, and can also be configured based on ESG provider and network operator in the similar method.

TABLE 12

A format of the IP platform-based service mapping information response message is shown in Table 13. The service mapping information response message can also be configured based on network or ESG provider as shown in Table 13.

TABLE 13

FIG. 12 illustrates architecture of a home network according to first and second embodiments of the present invention. Only the entities for performing the logical functions related to the preferred embodiment of the present invention in the SM blocks of the visited network and the home network are shown herein.

Referring to FIG. 12, an SA 1102a generates service data by combining related metadata and broadcast contents from multiple sources to provide a particular service, encodes the service data in the format interpretable by the terminal 1100, provides the coded service data to the terminal 1100 through streaming or file carrousel delivery, and generates metadata including a service description to be used for an ESG.

An ESG entity 1202 in an SM 1102b generates an ESG using metadata provided from the SA 1102a, and delivers the ESG. A Service Configuration &

Resource Allocation entity 1204, in charge of service configuration and allocation of network resources, makes a contention over a bandwidth of a broadcast bearer through communication with the SA 1102a, allocates services in positions on a broadcast network topology, determines a service bandwidth, and schedules service time.

A Security/Service Protection provision entity 1206 takes charge of security/authentication, service protection and service provisioning. The entities 1202 to 1206 are connected to an MM block 1200 and perform the functions necessary for handover. The MM block 1200 performs operations related to mobility of the terminal 1100, especially to handover and roaming. In particular, according to the present invention, the MM block 1200 exchanges service mapping information request and response with the terminal 1100, and generates service mapping information using the service information acquired from neighboring networks. Also, the MM block 1200 performs communication with other entities and sub-entities to support the roaming procedure. For information exchange, the MM block 1200 performs communication with MM blocks in other networks.

FIG. 13 illustrates architecture of a terminal according to first and second embodiments of the present invention.

Referring to FIG. 13, the terminal 1100 includes not only a broadcast receiver 1302 capable of receiving broadcast signals from a Broadcast Network 1102d, but also an interactive adaptor 1304 capable of accessing an Interactive Network 1102c. The broadcast receiver 1302 receives service data or signaling information from the Broadcast Network 1102d, and the interactive adaptor 1304 exchanges service data or signaling information via the Interactive Network 1102c. An MM block 1300 performs the handover-related operations described above. At least one of the entities 1302 and 1304 receives an ESG, detects handover information therefrom, and then sends the roaming information to the MM block 1300, and the MM block 1300, to process the roaming-related operation, is connected to a Subscription Management block 1310 in charge of a management/acquisition procedure for terminal rights related to service subscription, and a decryption procedure for service contents, and a content consumption block 1312 for providing audio and video of a broadcast service to users.

As is apparent from the foregoing description, the present invention enables exchange of service mapping information between the home network and its neighboring networks, thereby supporting service continuity of the terminal that is receiving a particular service. The present invention supports service continuity taking characteristics of service contents into account, or notifies the terminal and its user that the identical service is provided even in the neighboring network, taking the time difference into account, thereby facilitating efficient scheduling during service reception of the terminal.

That is, the present invention can fast support the service requested by the terminal using the service mapping information exchanged between the home network and its neighboring network, without the need that the user moves to the neighboring network and receives a new ESG therefrom.

In addition, the present invention supports broadcast with service continuity using the service mapping information, thereby attracting more users to consume the services and thus motivating the service operators.

While the invention has been shown and described with reference to a certain preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A method for providing service continuity in a home network of a digital broadcasting system, the method comprising: acquiring, from a neighboring network, service information for broadcast services provided in the neighboring network; comparing the service information acquired from the neighboring network with currently provided service information, and generating service mapping information indicating at least one second broadcast service being similar or identical to a first broadcast service currently provided to a terminal, among broadcast services provided in the neighboring network; and transmitting the generated service mapping information to the terminal so that the terminal can continuously receive the broadcast service after roaming to the neighboring network.

2. The method of claim 1, wherein the service mapping information includes service identifiers (Service IDs) of the first and second broadcast services, Internet Protocol (IP) addresses of the home network and the neighboring network, Electronic Service Guide (ESG) provider identifiers (ESG provider IDs) of the home network and the neighboring network, and IP platform identifiers (IP platform IDs) of the home network and the neighboring network.

3. The method of claim 2, wherein the service mapping information further comprises content type information indicating whether the first and second broadcast services are identical or similar to each other.

4. The method of claim 3, wherein the service mapping information further comprises at least one of time difference information between the first and second broadcast services, and access information with which the terminal accesses the neighboring network.

5. The method of claim 3, wherein the service mapping information further comprises information indicating whether the broadcast services provided in the home network and the neighboring network are identical or similar to each other.

6. The method of claim 1, wherein the service mapping information is transmitted along with an ESG.

7. The method of claim 1, wherein the service mapping information transmitted along with Program Specific Information/System Information

(PSI/SI).

8. The method of claim 1, wherein the service mapping information is transmitted via an interactive network.

9. The method of claim 1, wherein the generation of service mapping information comprises: generating the service mapping information in response to a request from the terminal.

10. A method for receiving service continuity from a neighboring network by a terminal in a digital broadcasting system, the method comprising: determining whether there is a need for roaming; if it is determined that there is a need for roaming, issuing a request for service mapping information indicating at least one second broadcast service being identical or similar to a first broadcast service currently received from a home network, among broadcast services provided in at least one neighboring network; and upon receipt of a service mapping information response message with service mapping information from the home network, continuously receiving the second broadcast service in succession to the first broadcast service from a selected one of at least one neighboring network using the service mapping information.

11. The method of claim 10, wherein the receiving of the broadcast service comprises: searching for the at least one neighboring network capable of providing the second broadcast service using the received service mapping information; selecting a neighboring network having highest signal strength among the searched neighboring networks; and receiving the second broadcast service from the selected neighboring network.

12. The method of claim 10, wherein the service mapping information includes service identifiers (Service IDs) of services provided in the home network and the neighboring network, Internet Protocol (IP) addresses of the home network and the neighboring network, Electronic Service Guide (ESG) provider identifiers (ESG provider IDs) of the home network and the neighboring network, and IP platform identifiers (IP platform IDs) of the home network and the neighboring network.

13. The method of claim 11, wherein the service mapping information further comprises content type information indicating whether the broadcast services provided in the home network and the neighboring network are identical or similar to each other.

14. The method of claim 13, wherein the service mapping information further comprises time difference information between the services provided in the home network and the neighboring network, and access information with which the terminal accesses the neighboring network.

15. The method of claim 14, wherein the continuous reception comprises: compensating for a time difference between the first broadcast service and the second broadcast service using the time difference information, before the reception.

16. The method of claim 10, wherein the service mapping information is transmitted along with an ESG.

17. The method of claim 10, wherein the service mapping information transmitted along with Program Specific Information/System Information (PSI/SI).

18. The method of claim 10, wherein the service mapping information is transmitted via an interactive network.

19. A digital broadcasting system for providing service continuity to a terminal, the system comprising: a home network for acquiring, from a neighboring network, service information for broadcast services provided in the neighboring network, comparing the acquired service information with service information for broadcast services provided in the home network, generating service mapping information indicating at least one second broadcast service being similar or identical to a first broadcast service currently provided to the terminal, among broadcast services provided in the neighboring network, and transmitting the generated service mapping information to the terminal; and the terminal for receiving the service mapping information, and continuously receiving the second broadcast service in succession to the first broadcast service from a selected one of at least one neighboring network using the service mapping information.

20. The digital broadcasting system of claim 19, wherein the service mapping information includes service identifiers (Service IDs) of services provided in the home network and the neighboring network, Internet Protocol (IP) addresses of the home network and the neighboring network, Electronic Service Guide (ESG) provider identifiers (ESG provider IDs) of the home network and the neighboring network, and IP platform identifiers (IP platform IDs) of the home network and the neighboring network.

21. The digital broadcasting system of claim 20, wherein the service mapping information further comprises content type information indicating whether the broadcast services provided in the home network and the neighboring network are identical or similar to each other.

22. The digital broadcasting system of claim 21, wherein the service mapping information further comprises time difference information between the services provided in the home network and the neighboring network, and access information with which the terminal accesses the neighboring network.

23. The digital broadcasting system of claim 19, wherein the service mapping information is transmitted along with an ESG.

24. The digital broadcasting system of claim 19, wherein the service mapping information transmitted along with Program Specific

Information/System Information (PSI/SI).

25. The digital broadcasting system of claim 19, wherein the service mapping information is transmitted via an interactive network.

26. The digital broadcasting system of claim 19, wherein the home network generates the service mapping information in response to a service mapping information request from the terminal.