KR100856274B1 - Method and Apparatus for Supporting Handover Using Interactive channel in DVB-H CBMS system - Google Patents

Abstract

The present invention is a mobile digital video broadcasting (DVB-H) convergence service (CBMS) system in the Convergence of Broadcasting and Mobile Service (CBMS) system even if the user moves out of the cell (cell) or network to which he belongs The present invention proposes a device and a method for selecting and watching a service continuously. In the present invention, essential or useful information is delivered to a terminal to be handed over using an interactive channel. Therefore, even if the user moves while watching the service selected by the user and enters a new cell, the terminal can perform the handover using the conventional method and the enhanced method. By providing such an enhanced handover scheme, the present invention can provide a seamless service to a user. In addition, it provides a handover execution scenario of the terminal in a mobile environment.

Handover, passive handover, Digital Video Broadcasting-handheld (DVB-H), Convergence of Broadcasting and Mobile Service (CBMS)

Description

Method and Apparatus for Supporting Handover Using Interactive Channel in Portable Digital Video Broadcasting Convergence Service System {Method and Apparatus for Supporting Handover Using Interactive channel in DVB-H CBMS system}

1 is a system configuration diagram illustrating the concept of handover in a general portable digital video broadcasting.

2 is a diagram illustrating a message exchange procedure of handover according to the prior art.

3 is a flowchart illustrating the operation of a terminal according to the prior art.

4 is a flowchart illustrating the operation of a network according to the prior art.

5 is a diagram illustrating a message exchange procedure of handover according to a preferred embodiment of the present invention.

6 is a flowchart illustrating the operation of a terminal according to an exemplary embodiment of the present invention.

7 is a flowchart illustrating operation of a network in accordance with a preferred embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Digital Video Broadcasting-handheld (DVB-H) DVB-H (Convergence of Broadcasting and Mobile Service; CBMS) system, in particular hand. Provided are a method and an apparatus for providing handover related information to a terminal using an interactive channel to a terminal to perform over.

DVB-H CBMS is a service that provides more convenient functions through the combination of digital TV broadcasting service with excellent mobile reception performance and mobile communication. In other words, with the conversion of analog TV to digital, HDTV-quality high-definition and CD-quality high-quality TV service can be enjoyed in the room. However, with the diversification of modern society, viewers' activities and life patterns have also changed from the past, and as portable devices such as mobile phones, PDAs, and notebook computers have become commonplace, the demand for enjoying clear-quality TV on the go is rapidly increasing. have. In addition, there is an effort to solve the limitation of the broadcast network without the reverse channel through a combination with mobile communication, the result of this effort is the DVB-H CBMS.
The DVB-H CBMS is a system designed for a receiving terminal capable of using a mobile communication channel. The DVB-H CBMS includes a concept of handover supported by cell-based wireless communication such as a conventional mobile communication system. However, handover of DVB-H CBMS is different from handover of mobile communication system. Handover of mobile communication system receives measurement report for network management including handover while network manages individual users. In general broadcasting system, broadcaster provides service and content. It does not manage individual users. Therefore, the broadcast system also sends information for broadcast reception to all users using the broadcast network, and does not have a user management function. Accordingly, handover of a broadcasting network requires unique technical matters that are distinguished from handover of a mobile communication system. In addition, the handover of the broadcasting network aims to provide a continuous service without interruption even when the user moves.

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1 is a system configuration diagram illustrating the concept of handover in a general portable digital video broadcasting.

Referring to FIG. 1, when the user 100 moves to another cell 130 belonging to the same network while watching the service selected by the cell 120 to which the user 100 belongs, the service that the user 100 is watching In order to provide continuously, the same transport stream as the transport stream received from the cell 120 should be able to be received from the moving cell 130. If the transport stream is different, at least the same service should be included in the transport stream provided by the cell 130 to which the same service is moving.

Since different cells have different transmission frequencies, the terminal needs to know frequency information of neighbor cells in order to perform handover. The frequency information of the neighbor cell may be obtained through program specific information / service information (hereinafter, referred to as PSI / SI) provided by the DVB broadcasting network.

If the user 110 enters the neighboring network 150 out of the network 140 to which the user 110 belongs, the terminal may be connected to the neighboring network to which the service that the user 110 is watching is in addition to the frequency information. You need to know the id of the transport stream. This information can also be known through PSI / SI information. If there is no service that the user was watching in the neighboring network, the terminal performs a process of searching for an alternative service. In this case, the alternative service refers to a service having the same composition but different characteristics depending on the region, such as news. And roaming may be necessary when connecting to other networks. The above-described handover aims to provide a continuous service without interruption even when the user moves.

Prior to the above, it is necessary to establish the concept of passive handover and active handover.

The passive handover means that the terminal controls the handover, and information on neighboring transport streams and services should be provided through the transport stream. A representative method of delivering information through the transport stream is a method using PSI / SI. When the passive handover scheme is applied, an access parameter may be provided through an interactive channel.

The active handover refers to a method in which an internet protocol datacast (IPDC) service network controls handover. In this case, an interactive channel is absolutely necessary, and broadcast content can be delivered using the interactive channel through active handover.

Hereinafter, the operation principle of the handover that should be preceded to explain the present invention will be described.

2 is a diagram illustrating a message exchange procedure of handover according to the prior art.

Before describing the operation of FIG. 2, entities necessary for performing handover will be described. In detail, the content source entity 200 of the service application is an entity that serves to provide content to be viewed by the user. The PSI / SI generator entity 210 in the broadcast network is an entity that collects PSI / SI information and delivers the PSI / SI information to a terminal through a broadcast network. The content consumption entity 220 in the terminal is an entity for viewing content provided by the broadcast service provider. The PSI / SI handler entity 230 is an entity that is responsible for decoding of a received broadcast signal and related service operation based on information obtained by receiving PSI / SI information provided by a broadcast network. Although the mobility manager 240 does not perform a special function in FIG. 2, the mobility manager 240 serves to provide a continuous service even when the terminal moves.
Based on the role of the entity described so far, the detailed message exchange procedure in handover is as follows.
In the state before entering the handover, the terminal receives the service from the contents source entity 200 in step 250 and watches the selected program. If the strength of the received signal falls while watching the program, the terminal selects candidate cells suitable for its location based on PSI / SI information (PSI / SI_before) in step 260 and signs during off time in step 270. The reception strength of the cells is measured. When a suitable cell is found as a result of the measurement, a frequency is adjusted and a handover is performed. Since the message exchange procedure in the drawings for explaining the present invention will be divided before and after the handover using a dotted line.
After performing the handover, the terminal finds a transport stream to be received and continues to receive it. In step 280 of the process, PSI / SI information (PSI / SI_after) of the new cell is received, and the decoding process is performed based on the received information. After the decoding process, the terminal receives the service from the new cell in step 290, so that the user can continuously receive the service selected by the user.

Herein, it is assumed that the PSI / SI information transmission and reception process according to the present invention including the PSI / SI information reception process of steps 260 and 280 continues without interruption through the broadcasting network. Therefore, for convenience of explanation, it is indicated that the PSI / SI information is received after completing a specific procedure, but the above process is continuously performed while receiving a broadcast.

3 is a flowchart illustrating an operation of a terminal when performing a handover according to the prior art.

Referring to FIG. 3, when the terminal starts to operate, it is checked whether the strength of the received signal decreases periodically in step 310 while receiving a broadcast service in step 300. If there is no decrease in the reception intensity, the process returns to step 300 to continue receiving the broadcast service. If there is a decrease in reception sensitivity, the process proceeds to step 320 to obtain frequency information of a neighboring cell or network from the PSI / SI information. . A cell or network that knows the frequency information belongs to a candidate group for handover. After obtaining the frequency-related information through the PSI / SI, in step 330, the terminal measures the reception strength of the neighboring cell or network during the off time.

In step 311, it is checked whether there is a frequency exceeding a predetermined threshold among the measured reception strengths of the candidate group. If a frequency exceeding a predetermined threshold is found, the process proceeds to step 312. If there is no frequency exceeding the predetermined threshold, the process proceeds to step 350 to perform an initial setup process.
Proceeding to step 350 means that the received signal strength drops below a threshold to reach a situation in which the broadcast service can no longer be received. Therefore, the terminal returns to the initial stage of searching for the broadcast service and performs the setup process again. It is. In step 350, the terminal capable of receiving the broadcast service again returns to step 300 to receive the broadcast service. However, when the terminal performs step 350, the user may experience disconnection of the service he / she is watching.
On the other hand, if a frequency exceeding a threshold value is found in step 312, but the service that the user is watching is not included in the frequency, the process moves to step 350 as well. same.

On the other hand, if a frequency exceeding a threshold value is found in step 312, and the service includes the service being viewed by the user, the process proceeds to step 340 to perform a tuning operation. The tuning operation is a task for shifting a reception frequency and finding a corresponding transport stream that a user is watching so as to continuously receive a service. After completing step 340, the handover process has been completed, and the terminal returns to step 300 to continuously receive service.

4 is a flowchart illustrating the operation of a network when performing a handover according to the prior art.

Referring to FIG. 4, when the network starts to operate, the broadcast service is transmitted in step 400 and the PSI / SI information is transmitted in step 410. That is, in the conventional handover, the network only transmits broadcast service and essential / additional related information.

As described above, the handover of the related art can provide a handover service according to a user's movement in the simplest manner. However, when the handover service is not received through PSI / SI, the handover fails to be viewed. There was a problem that the disconnection of the existing service occurs.

The present invention, which was devised to solve the above problems, provides a method and apparatus for providing information to a terminal to perform handover through an interactive channel in a portable digital video broadcasting (DVB-H) convergence service (CBMS) system. do.

In addition, the present invention is a method for transmitting request information to a terminal that wants to obtain handover related information using an interactive channel to a terminal to perform handover in a portable digital video broadcasting (DVB-H) convergence service (CBMS) system And an apparatus.

In addition, the present invention, in the digital video broadcasting (DVB-H) telecommunication convergence service (CBMS) system using a mobile communication channel interactive channel (interactive channel) to view the selected service by the user to move the cell to which he belongs The present invention provides a method and apparatus that can watch a service without interruption.

According to an embodiment of the present invention, in a portable digital video broadcasting convergence service system, a terminal performs handover, wherein the terminal confirms a reception strength of a broadcast service currently being received by the terminal and connects the terminal to a network through an interactive channel. Requesting handover related information of a located region, selecting a new handover candidate cell based on the handover related information received from the network through the interactive channel, and receiving the broadcast service signal reception strength of the candidate cells; Performing a measurement, searching for a new reception frequency, performing a tuning operation of searching for a transport stream of a service currently being received by moving the reception frequency to the found frequency, and continuing receiving the service currently being received. Characterized in that.
In addition, an embodiment of the present invention, in a portable digital video broadcasting convergence service system, a method for supporting a handover of a terminal by a network, the method comprising: transmitting a broadcast service and program specific information / service information (PSI / SI), Receiving a handover related information request message from the terminal through an interactive channel; and transmitting the broadcast service, the PSI / SI, and the handover related information through the interactive channel.
In addition, an embodiment of the present invention is a portable digital video broadcasting convergence service system supporting handover, comprising: a terminal requesting a handover when a strength of a service currently being received is equal to or less than a reference value; A network for transmitting information (PSI / SI), generating a channel for delivering the broadcast service to the terminal, and delivering the broadcast service and the PSI / SI through the generated channel, wherein the network includes: Receiving the handover request from the terminal and delivers the handover related information through the generated channel.
In addition, an embodiment of the present invention is a terminal device for performing a handover in a portable digital video broadcasting convergence service system, a content consumption unit for receiving a broadcast service from a broadcast network, and program specific information / service information from the broadcast network. Requesting handover related information to a network through a PSI / SI handler for receiving (PSI / SI) and an interactive channel, selecting a new handover candidate cell based on the handover related information received from the network, and receiving a new reception And a mobility manager configured to search for a frequency and move a reception frequency to the found frequency to find a transport stream of a service currently being received.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

The present invention described below is not limited to PSI / SI for obtaining information necessary for performing handover in configuring a DVB-H CBMS service system. In addition, the present invention provides a method and apparatus for delivering essential additional information to a terminal to attempt handover under the assumption that an interactive channel is provided.

5 is a flowchart illustrating a message exchange procedure of handover according to a preferred embodiment of the present invention.
The entity required to perform the handover according to the embodiment of the present invention is the same as described above with reference to FIG. 2 except for the Mobility Manager entity 510 in Serviece Management, and thus redundant description thereof will be omitted. The Mobility Manager entity 610 is responsible for receiving a parameter request message from the terminal and transmitting a parameter request message for requesting to inform the PSI / SI generator entity 520 of information corresponding to the request terminal in the broadcast network. .
Looking at the message exchange procedure during the handover according to an embodiment of the present invention as follows.

Referring to FIG. 5, in the state before entering the handover, the terminal watches the selected program by receiving the service from the contents source entity 500 in step 551. If the strength of the received signal drops afterwards, the terminal selects candidate cells suitable for its location based on the PSI / SI information (PSI / SI_before) transmitted from the PSI / SI generator 520 of the broadcast network in step 560, and turns off the terminal. The reception strength of the selected candidate cells is measured during off time. If the terminal fails to acquire the PSI / SI information or if it is difficult to perform handover only with the provided PSI / SI information, in step 570, the access parameter, which is necessary information, is transmitted to the Mobility Manager 510 of the service manager through the bidirectional channel. Send a message (Access_parameter_req) requesting to give. The transmitted access parameter request message is configured as shown in Table 1 below.

Hand_over_type, the first item of Table 1, is an identifier indicating the type of handover requested by the terminal. If the type of handover requested by the terminal is passive handover, the network helps to perform the handover by providing information to the terminal without changing the current service configuration. In the passive handover category, when the terminal has a wide range of choices that can be requested, the identifier may be used to distinguish the type of requested information. The second item, terminal_id, is an identifier in the mobile communication network of the terminal requesting the handover. The identifier is used when the network identifies the requesting terminal, and is used when the network side wants to send a response according to the request of the terminal. If it is possible to interwork with the mobile communication network, the broadcasting network or service provider may obtain the location information of the user grasped by the mobile communication network through the identifier.

The third item, Service_id, is an identifier for a service currently received by the requesting terminal. The identifier uses a service id defined in the standard for DVB broadcasting service, and its role is a criterion for the network to filter out only the corresponding cell when selecting a candidate cell. If not, it may be a criterion for proposing alternative services. An example of an alternative service here is to notify the local news of the region to which the user has moved if the user is watching the local news.

The fourth item, Cell_id, is an identifier indicating the cell of the broadcast network currently being received by the requesting terminal. Cell_id may be a reference when the network determines the location of a cell to which the requesting terminal belongs and sends PSI / SI information for a corresponding region.
The fifth item, loc_inf, is an optional element. When the requesting terminal knows its location precisely through an additional device such as GPS and can inform its network of its location and current direction, This can be useful for selection.

After receiving the access parameter request message in step 570, the mobility manager entity 510 in service management requests to inform the PSI / SI generator entity 520 in the broadcast network of information corresponding to the requesting terminal in step 580. Sends a parameter request message (Parameter_req).
The PSI / SI generator entity 520 in the broadcast network sends a parameter response message (Parameter_res) according to the parameter request message to the mobility manager entity 510 in the service management in step 581.
Thereafter, in the service management, the mobility manager entity 510 transmits the access parameter response message (Access_parameter_res) to the mobility manager 550 of the requesting terminal in step 571.
The terminal measures the reception strength of neighboring cells during off time based on the information received in step 590, and if a suitable cell is found, adjusts the frequency and performs handover. After performing the handover, in step 561, the PSI / SI information is received from the new cell, the transport stream to be received is searched for, and the reception is continued. If handover occurs to another network, the roaming portion is executed after the step 590 of adjusting the frequency. Detailed roaming procedure and method according to this is in accordance with the details described in Korean Patent Application No. 2006-3684 'User and service roaming method and system in a digital video broadcasting system'. After completing step 561, the terminal receives the service from the new cell in step 591, so that the user can continuously receive the service selected by the user.
Next, the messages transmitted in steps 580, 581, and 571 will be described according to embodiments.
<First Embodiment>

The parameter request message transmitted according to the first embodiment of the present invention is shown in Table 2 below.

The service_id, which is the first item in Table 2, is an identifier assigned to distinguish a request for information and serves to distinguish when two entities frequently exchange messages. The second item, request_type, is an identifier indicating the type of information requested by the mobility manager 510 to the PSI / SI generator 520. The third item, cell_id, is an identifier indicating a cell of the broadcasting network to which the requesting terminal belongs. The PSI / SI generator 520 filters only information corresponding to cell_id among all broadcasting network information and transmits the information to the mobility manager 510. The fourth item, loc_inf, is location information of the terminal and is additional information. It is used as a reference when selecting information to be transmitted.

The parameter response message transmitted according to the first embodiment of the present invention is shown in Table 3 below.

Table 3 above consists of PSI / SI information that can be received in the region where the requesting terminal is located. The role is the same as the role of a general PSI / SI to inform the terminal the necessary information. In this case, since the system considers handover, efficiency can be improved by removing irrelevant information from the information provided. Service_id, which is the first item of Table 3, has the same form and role as service_id of Table 2 described above.

The access parameter response message transmitted according to the first embodiment of the present invention is shown in Table 4 below.

Table 4 consists of PSI / SI information that can be received in the region where the requesting terminal is located. Since the role is the same as described above in (Table 3), redundant description is omitted.

Second Embodiment

The access parameter request message transmitted according to the second embodiment of the present invention is shown in Table 5 below.

Service_id, which is the first item in Table 5, is an identifier assigned to distinguish a request for information and serves to distinguish the two entities frequently. The second item, request_type, is an identifier indicating the type of information requested by the mobility manager 510 to the PSI / SI generator 520. The third item, cell_id, is an identifier indicating the cell l of the broadcasting network to which the requesting terminal belongs. The PSI / SI generator 520 takes only information corresponding to cell_id among all broadcasting network information and transmits the information to the mobility manager 510. The fourth item, loc_inf, is location information of the terminal and is a reference when selecting information to be transmitted as additional information.

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The parameter response message transmitted according to the second embodiment of the present invention is shown in Table 6 below.

Table 6 includes information on an ID of a cell that can be received in a region where a requesting terminal is located, a frequency list of the corresponding cell, and time information required to receive an IP packet. When information is classified according to its characteristics, it consists of a candidate cell, frequency information of the candidate cell, and additional information useful for performing handover. As an example of additional information useful for performing the handover, the present invention has received time information for completing handover in order to receive handover_available_time, which is a packet received by the requesting terminal. In the case of useful information, if hand_over_type and message format are designated, the information can be delivered through the method proposed by the present invention.

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The Access parameter response message transmitted according to the second embodiment of the present invention is shown in Table 7 below.

<제3 실시예>

Third Embodiment

The parameter request message transmitted according to the third embodiment of the present invention is shown in Table 8 below.

Service_id, which is the first item in Table 8, is an identifier assigned to distinguish a request for information and serves to distinguish the two entities frequently. The second item, request_type, is an identifier indicating the type of information requested by the mobility manager 510 to the PSI / SI generator 520. The third item, cell_id, is an identifier indicating the cell l of the broadcasting network to which the requesting terminal belongs. The PSI / SI generator 520 takes only information corresponding to cell_id among all broadcasting network information and transmits the information to the mobility manager 510. The fourth item, loc_inf, is location information of the terminal and is a reference when selecting information to be transmitted as additional information.

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The parameter response message transmitted according to the third embodiment of the present invention is shown in Table 9 below.

Table 9 shows the ids of the cells that can be received in the region where the requesting terminal is located, the frequency list of the corresponding cells, the time information required to receive the IP packet without exception, and the number of candidate cells that the terminal can access. In many cases, the network consists of information that informs the candidate cells of the handover candidate cell. When information is classified according to its characteristics, it consists of a candidate cell, frequency information of the candidate cell, and additional information useful for performing handover.

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The Access parameter response message transmitted according to the third embodiment of the present invention is shown in Table 10 below.

The difference between the third embodiment and the second embodiment of the present invention is that, in the third embodiment, when the number of candidate cells accessible by the terminal is large, only the most likely candidate cell is sent unlike the second embodiment. In detail, the broadcast service network may know the physical location of the requesting terminal through the cell_id sent by the requesting terminal through the mobile communication network, if available, and through the Loc_inf information, if available. Therefore, when the access parameter is sent, only the information about the cell around the location of the requesting terminal can be selected and sent instead of the information about all cells of the broadcasting network. In this case, the handover request terminal can reduce the number of handover candidate cells, thus simplifying the handover procedure.

If the above-described first, second and third embodiments are handovers to other networks, there is information that can be added when the 571 message is transmitted. When performing the handover to another network as described in FIG. 1, if the same service as the service being viewed is provided, the same service is searched for and the user continues to watch. If the same service is not provided, the alternative service must be found to connect the city hall. Roaming may also be necessary. In the present invention, when handing over to another network, information necessary for handover to another network can be transmitted to the 571 message. For example, the additional information may include a service ID of an alternative service, an address (URL) or access point of another network for applying for roaming, roaming charge guide information, and the like. If the cell to be handed over is another network, the classification method is possible by replacing the cell_id with the id of the network.
When handing over to another network, the Access parameter response message transmitted according to the additional information transmission embodiment is shown in Table 11 below.

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6 is a flowchart illustrating an operation of a terminal during handover according to an exemplary embodiment of the present invention.

Referring to FIG. 6, when the terminal starts to operate, it is checked whether the strength of a received signal decreases periodically while receiving a broadcast service in step 600. In step 610, if there is no decrease in the reception strength, the process returns to step 600 to continue receiving the broadcast service. If there is a decrease in reception sensitivity, the process proceeds to step 620 in which the neighboring cell or network of the PSI / SI information is determined from the PSI / SI information. Obtain frequency information. Cells or networks that know the frequency information belong to candidate groups for handover.

When the frequency-related information is acquired through the PSI / SI, the terminal measures the reception strength of the neighboring cell or network during off time in step 630. If a frequency exceeding a predetermined threshold value is found in the candidate crowd in step 640, the method proceeds to step 650 in which the user is watching whether there is a service that the user is watching. Up to step 650 is the same as the conventional handover using PSI / SI. If the terminal performs passive handover using the interactive channel immediately after step 610, the terminal may perform the handover. Of course, the upper and lower relations of the statues can be changed.

If the frequency exceeding the predetermined threshold is not found or if the frequency exceeding the threshold does not exist in step 640, the method proceeds to step 670 to request the handover related information from the network. In step 670, the terminal cannot perform handover based on only the information obtained through the broadcasting network. The request process is performed using the interactive channel, and various embodiments exist according to the request of the terminal. After completing step 670, the terminal receives the response from the network in step 680, and receives the requested information through the interactive channel. Upon receiving the response from the network in step 680, the terminal selects a new handover candidate cell based on the information obtained in step 690. After that, the process returns to step 630 with the new candidate cell and proceeds again.

As such, comparing the scheme of FIG. 6 with the conventional scheme, reaching 670 means that the terminal has failed to perform the handover using only conventional PSI / SI information. The initial setup process had no choice but to revisit the service the user required. However, according to the handover scheme proposed in the present invention, the terminal obtains the information necessary for handover through a series of processes (steps 670 through 690) of requesting handover related information to the network and receiving a response, and then again proceeds with steps 630 through 650. Repeat the steps to find a suitable cell to perform a handover. Thereafter, if there is a service that is watching at a frequency exceeding the threshold in step 650, the tuning operation of step 660 is performed. The tuning operation is a task for shifting a reception frequency and finding a corresponding transport stream that a user is watching so as to continuously receive a service. After completing step 660, the handover process is completed. The terminal returns to step 600 and receives service continuously.

7 is a flowchart illustrating the operation of a network during handover according to a preferred embodiment of the present invention.

Referring to FIG. 7, when the network starts to operate, the broadcast service is transmitted in step 700 and the PSI / SI information of step 710 is simultaneously transmitted. The network checks whether a handover related information request is received from the terminal through the bidirectional channel periodically in step 720 while performing steps 700 and 710. If there is no request from the terminal, the check of step 720 is periodically performed while repeating steps 700 and 710. In this case, if there is a handover related request from the terminal, the process proceeds to step 730 to transfer the relevant PSI / SI information based on the location information of the requesting terminal. Operation 730 may have various embodiments, and specific embodiments are described in the description of FIG. 5.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

In the present invention operating as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

The present invention provides a seamless service even when the mobile terminal moves while watching a service selected by a user terminal using an interactive null in a portable digital video broadcasting telecommunication convergence service system and moves out of a cell or network to which the user terminal belongs. In addition, by reducing the handover candidate cell of the terminal using the interactive channel, it is possible to obtain a benefit of reducing power consumption and handover time of the terminal.

Claims (10)

A method for a terminal performing handover in a portable digital video broadcasting convergence service system, Checking, by the terminal, the reception strength of a broadcast service currently being received and requesting handover related information of a region where the terminal is located through an interactive channel through a network; Selecting a new handover candidate cell based on the handover related information received from the network through the interactive channel, and measuring a broadcast service signal reception strength of the candidate cells; Performing a tuning operation of searching for a new reception frequency and finding a transport stream of a service currently being received by moving the reception frequency to the found frequency; And continuing to receive the currently received service. The method of claim 1, If there is no broadcast service being received by the terminal at the found frequency, the method returns to the process of requesting the handover related information. The method of claim 1, The handover related information, Handover method, characterized in that the program specific information / service information (PSI / SI) information of the cell or network in which the terminal is located. The method of claim 1, The handover related information, The most likely candidate cell when there are a plurality of candidate cells that can be received in the region where the terminal is located, frequency information of the candidate cells, time information required to receive an Internet protocol packet, and a plurality of candidate cells that the terminal can access. Handover method comprising at least one of the selected information. The method of claim 1, The process of requesting the handover related information may include: The terminal checks the reception strength of the broadcast service currently being received, acquires frequency related information of candidate cells neighboring its location based on the PSI / SI received together with the broadcast service, and broadcast service signal of the candidate cells. Measuring the reception strength, If a frequency in which the reception intensity exceeds a reference value is searched, searching for whether there is a broadcast service being received by the terminal at the found frequency; Requesting handover related information of a region where the terminal is located through the interactive channel if a frequency exceeding the reference value is not found or if the broadcast service that the terminal is receiving is not present in the found frequency. Handover method, characterized in that. A method for supporting handover of a terminal in a portable digital video broadcasting convergence service system, Transmitting a broadcast service and program specific information / service information (PSI / SI), Receiving a handover related information request message from the terminal through an interactive channel; And transmitting the broadcast service, the PSI / SI, and the handover related information through the interactive channel. The method of claim 6, The handover related information, The most likely candidate cell when there are a plurality of candidate cells that can be received in the region where the terminal is located, frequency information of the candidate cells, time information required to receive an Internet protocol packet, and a plurality of candidate cells that the terminal can access. Handover method comprising at least one of the selected information. In a portable digital video broadcasting convergence service system supporting handover, A terminal requesting handover when the strength of a service currently being received is equal to or less than a reference value; A network for transmitting a broadcast service and program specific information / service information (PSI / SI), generating a channel for delivering the broadcast service to the terminal, and delivering the broadcast service and PSI / SI through the generated channel; Include, The network, And receiving the handover request from the terminal, and transmitting handover related information through the generated channel. The method of claim 8, The handover related information, The most likely candidate cell when there are a plurality of candidate cells that can be received in the region where the terminal is located, frequency information of the candidate cells, time information required to receive an Internet protocol packet, and a plurality of candidate cells that the terminal can access. A portable digital video broadcasting convergence service system comprising at least one of the selected information. A terminal apparatus for performing handover in a portable digital video broadcasting convergence service system, A content consuming unit for receiving a broadcast service from a broadcast network; A PSI / SI handler for receiving program specific information / service information (PSI / SI) from the broadcasting network; Requesting handover related information to the network through the interactive channel, selecting a new handover candidate cell based on the handover related information received from the network, searching for a new receiving frequency and shifting the receiving frequency to the found frequency And a mobility management unit that performs a tuning operation to find a transport stream of a service being received.

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