KR20090061164A - Dmb handover method and system using road link-based channel quality information - Google Patents

Abstract

A DMB handover method using road based channel quality information and a system thereof are provided to supply a continuous broadcast to a DMB viewer moving to another viewing zone and supply a high quality broadcast service. A storage unit stores road based channel quality information and service relation information. A search frequency selection unit(1170) uses a current location of a DMB receiver and road based channel quality information to determine a handover target frequency search sequence. A service continuity determiner(1140) verifies whether to support service continuity of a frequency to be searched by referring to the service relation information. A quality measuring unit(1120) measures quality of a DMB signal to determine whether to start handover.

Description

Digital multimedia broadcasting handover method and system using channel quality information by road segment {DMB Handover Method and System Using Road Link-Based Channel Quality Information}

The present invention relates to a digital multimedia broadcasting handover method and a system using channel quality information for each road segment. More particularly, the present invention relates to maintaining a channel quality information for each road section previously measured and collected at a receiving terminal. The present invention relates to a digital multimedia broadcasting handover method and a system using channel quality information for each road section, which can prevent an unnecessary channel search procedure and perform a faster and more effective handover.

Recently, the viewing pattern of TV is greatly changed due to the convergence of broadcasting and communication technologies. The advent of Digital Multimedia Broadcasting (DMB), which enables users to enjoy clear broadcasts on high-speed trains, enables the viewing of personalized broadcasts that are not limited by time and space.

In other words, the advent of DMB is no longer needed to hurry up in front of the TV in the living room to watch dramas or sports broadcasts.

In Korea, terrestrial DMB has recently been activated, starting with the initial satellite DMB. Terrestrial DMB refers to providing a digital mobile multimedia broadcasting service to a subscriber mobile receiver using a terrestrial repeater.

Here, the terrestrial repeater may be assigned different frequencies for each zone, and the area serviced by the terrestrial repeater, that is, cell coverage is limited.

To ensure service continuity, the DMB receiver must perform DMB handover when moving out of the cell coverage of the currently connected terrestrial repeater to the service area of another terminator.

For DMB handover, the DMB receiver may scan the DMB signals received from the adjacent terrestrial repeater and check the currently available DMB signals. At this time, the DMB receiver processes the DMB handover in consideration of the signal strength, service ID, ensemble ID, etc. of the received DMB signal.

However, the conventional DMB receiver checks all currently received DMB signals in no particular order to determine the DMB handover, and thus, it takes a long time until the DMB handover is completed. In particular, service disruption due to handover delay could occur in certain regions. As a result, there is a problem that the overall DMB service quality is lowered.

An object of the present invention for solving the problems of the prior art as described above is to provide a digital multimedia broadcasting (DMB) handover method using the quality information for each road section.

Another object of the present invention is to enable continuous broadcasting viewing to DMB viewers moving to other viewing areas, and to provide a high quality broadcasting service required by the viewers.

Another object of the present invention is to provide a DMB receiver capable of performing a faster handover by loading channel quality information collected in advance on a road segment into a DMB receiver.

Another object of the present invention is to provide a method and system for transmitting the same to the DMB receiver when updating the channel quality table for each road section.

According to an embodiment of the present invention, a method of performing handover in a digital broadcast receiving apparatus is disclosed.

According to an embodiment of the present invention, a method for performing a handover in a digital broadcasting receiver includes: maintaining channel quality information for each road section in a predetermined recording area; A service quality checking step of checking whether a channel quality for a current service channel satisfies a preset channel quality threshold value; A search target channel selection step of selecting a search target channel for handover with reference to the channel quality information for each road section, if not satisfied; And performing a handover according to the channel quality of the selected discovery target channel.

According to another embodiment of the present invention, a digital broadcast receiving apparatus for performing a faster and more effective handover is disclosed.

According to an embodiment of the present invention, a digital broadcast receiver includes a storage unit for maintaining channel quality information and service relationship information for each road section;

A search frequency selection unit for determining a search order of a handover target frequency by using a current position of the digital broadcasting receiver and channel quality information of each road section; A service continuity judging unit verifying whether the frequency to be searched can support the service continuity of the current service channel with reference to the service relationship information; And a quality measuring unit which determines whether to initiate a handover by measuring the quality of the DMB signal.

The present invention has an advantage of providing a DMB handover method using channel quality information for each road section.

In addition, the present invention has the advantage of enabling a continuous broadcast viewing to the viewer using the DMB service, and providing a high quality broadcast service required by the viewer.

In addition, the present invention has the advantage of providing a DMB terminal capable of performing a faster and more optimized handover by loading the channel quality information for each road section collected in advance in the DMB receiver.

In addition, the present invention has the advantage of providing a method and system for transmitting the channel quality table for each road section to the DMB receiver.

Through the above advantages, the present invention can expect the effect of allowing more viewers to use the DMB service.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

The term and / or includes a combination of a plurality of related items or any item of a plurality of related items. The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

In this application, the terms "comprising" or "mounted" and "mounted" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described on the specification, one Or other features or numbers, steps, operations, components, parts or combinations thereof in any way should not be excluded in advance.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Other aspects, features, and advantages other than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

Hereinafter, a preferred embodiment of a digital multimedia broadcasting handover method and a system using channel quality information for each road section according to the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings and the contents described in the accompanying drawings, but the present invention is not limited or limited to the embodiments.

1 is a DMB network structure for explaining a method for performing handover using channel quality information for each road section according to an embodiment of the present invention.

As shown in FIG. 1, a portable receiver with a DMB function (hereinafter, referred to as a "DMB terminal 110" or a business card) transmits the DMB broadcast signal transmitted by the broadcasting station 120 to the DMB base station 130 or the DMB repeater ( 140). Here, the DMB repeater 140 solves the shadow area problem and amplifies and transmits a broadcast signal received from the DMB base station 130 to expand cell coverage for a broadcast service.

The DMB terminal 110 disclosed in the present invention may include a mobile phone, a PDA, a notebook computer, a vehicle receiver, etc. equipped with a DMB function.

The broadcast station 120 encodes and multiplexes the previously generated broadcasting content in a manner defined in the DMB broadcasting standard, where the wired channel may be configured using a coaxial cable or an optical cable. Transmit to the DMB base station 130 via a radio channel, eg, a broadcast satellite.

In addition, the broadcasting station 120 may receive the processed content from the broadcast content provider 160 that processes the content to be suitable for a specific broadcast service.

In particular, the broadcast signal may include not only user data but also service relationship information in which mutual mapping relationships between ensemble, frequency, and service for DMB handover are defined.

Definitions and interrelationships for the ensemble, frequency, and service will be described in detail with reference to FIGS. 3 to 6 to be described later.

The DMB terminal 110 according to an embodiment of the present invention may receive a channel quality information table for each road section through a predetermined return channel for DMB broadcasting and maintain it in a predetermined recording area.

Here, the return channel is a bidirectional control channel set between the broadcasting station 120 and the DMB terminal 110 and may be set through a mobile communication system. In general, the mobile communication system may be composed of a switch, a base station controller, a base station for mobile communication. A detailed description of the mobile communication system is not an essential component for describing the idea disclosed by the present invention and will be omitted below.

The channel quality information table for each road section includes channel quality information for each frequency measured for a corresponding road section through a field test. Here, the channel quality information includes information on reception quality measured for each channel and service of the DMB service, and includes electric field strength (dBm or dBuV / m), bit error rate (BER), and video service for each channel or service. It may include various items related to reception quality such as reception quality (Video Frame Error Rate, TS Packet Error Rate), audio service reception quality (Audio Frame CRC Error), data service reception quality (Data Packet CRC Error Rate).

Channel quality information for each frequency according to an embodiment of the present invention is collected in the unit of the corresponding link based on the national standard node and link operation guidelines for the entire DMB broadcast service area, and for selecting the search target frequency when the DMB channel handover Used for the purpose.

Each link is assigned a unique link identifier for the entire DMB service area, and the channel quality information table for each road section corresponds to link information corresponding to the corresponding link identifier, where the link information includes start position information and end of the road section. It may include location information and at least one transit area information, etc.-It may include at least one frequency information used in the region corresponding to the link identifier and the measured channel quality information for each frequency.

According to the present invention, the DMB terminal 110 initiates a handover procedure when the reception quality of the currently tuned broadcast service channel does not satisfy a preset threshold.

When the handover procedure is started, the DMB terminal 110 acquires its current location information and moving direction information, and checks the link identifier corresponding to the obtained location information and moving direction with reference to the channel quality information table for each road section. do.

Next, the DMB terminal 110 selects a frequency to be searched with reference to channel quality information for each frequency corresponding to the identified link identifier, and selects a continuity of the currently tuned service among at least one service corresponding to the selected frequency. Check whether there is a service that can be supported.

If present, the DMB terminal 110 performs a handover to a channel capable of supporting the continuity of the service. In this case, the search priority may be determined based on the channel quality information. For example, the frequency search order may be determined in order of good channel quality.

Of course, if there is no service that can support the continuity of the currently tuned service, the DMB terminal 110 starts searching for a frequency having a next higher priority.

The channel quality information table for each road section according to another embodiment of the present invention may include a cell identifier of at least one mobile communication base station covering a service area corresponding to the corresponding link identifier.

The DMB terminal 110 may obtain information on the current access cell identifier and the neighbor cell identifier through a control signal received from a mobile communication base station, for example, a BCH (Broadcasting Channel) of WCDMA. And a link identifier corresponding to the neighbor cell identifier through the channel quality information table for each road section.

According to another embodiment of the present invention, it should be noted that service relationship information for handover received through a fast information channel (FIC) may also be maintained in advance in the DMB terminal 110 through a return channel. . In this case, since the DMB terminal 110 does not need to periodically decode the FIC, the DMB terminal 110 may perform handover faster.

In addition, the DMB terminal 110 does not need to consume a separate power for FIC decoding, thereby reducing the battery consumption.

2 is an example of frequency allocation of a DMB service according to an embodiment of the present invention.

Referring to FIG. 2, a general DMB service may cover a relatively large area through one frequency band. For example, FIG. 2 shows that Chungcheongnam-do and Chungcheongbuk-do are assigned the 11th frequency and Jeollanam-do the eighth frequency.

In particular, adjacent frequencies may overlap each other, and handover may occur frequently in the overlapped periods. For example, the DMB terminal located at the border region of Chungcheongnam-do and Gyeonggi-do may perform handover in a section where the eighth frequency, the twelfth frequency, and the eleventh frequency overlap.

In particular, the DMB service network illustrated in FIG. 2 reuses frequencies so that the same frequencies do not overlap in order to maximize frequency use efficiency. For example, it can be seen that the thirteenth frequency allocated to Gangwon-do is used in some regions of Jeju Island.

In general, when a conventional DMB terminal is located in a region where a plurality of frequencies overlap, if it is determined that handover is necessary, the conventional DMB terminal has to search for all frequencies used in the region. Accordingly, there is a problem in that conventionally, service continuity due to handover delay cannot be guaranteed.

In order to solve the above problems, there is an advantage in that the channel quality information for each road section collected in advance is maintained on the DMB terminal, and frequency searching can be selectively performed using the same. That is, the present invention has an advantage of maintaining the continuity of the service or minimizing the disconnection of the service through faster handover.

3 is a view for explaining a DMB frequency allocation method according to an embodiment of the present invention.

As shown in FIG. 3, the frequency bands allocated for the DMB service are channel 8 310 and channel 12 320. Here, each channel is divided into an A band, a B band, and a C band, and a predetermined guard band is allocated between each band to avoid inter-frequency interference.

For example, channel 12 320 is divided into 12A band 321, 12B band 322, and 12C band 323, and broadcast service providers for each band may be allocated MBC, KBS, and SBS, respectively. .

The broadcast service provider may configure various broadcast service channels by subdividing the allocated bands. For example, the KBS may provide an ensemble of KBS star, KBS heart, and KBS TTI through the allocated 12B band 322. Here, the ensemble may be uniquely identified by the ensemble identifier as a set of services transmitted in a specific frequency band.

The services constituting the ensemble include audio, video, and data services, and may be composed of one or more service components.

The service is identified by the service identifier, and the DMB terminal preferably maintains the continuity of the service by transitioning to a frequency where the same service as the service currently being viewed is provided upon handover between frequencies.

4 is a diagram for explaining inter-frequency handover for the same ensemble according to an embodiment of the present invention.

Here, the same ensemble means that a set of services provided at different frequencies are the same. That is, the ensemble identifiers are the same.

Of course, services corresponding to each other included in two identical ensembles have the same service identifier.

Accordingly, in order to perform handover between frequencies having the same ensemble, relationship information between the ensemble and the frequencies is required.

Referring to FIG. 4, the ensemble identifier 0xE084 of the 11B band allocated to the Chungcheong region is the same as the ensemble identifier 0xE084 of the 12B band allocated to the Chonbuk region. Therefore, the DMB terminal moving from the Chungjeong area to the Jeonbuk area needs to shift the reception frequency from the 11B band to the 12B band while maintaining the current service when handover between frequencies.

5 is a diagram for explaining handover between frequencies for different ensembles according to an embodiment of the present invention.

As shown in FIG. 5, it can be seen that the ensemble identifier 0xE044 corresponding to the 12B band of the Seoul area is different from the ensemble identifier 0xE084 corresponding to the 11B band of the Chungcheong area.

That is, it can be seen that the combination of services provided in the Seoul area and the Chungcheong area is different from each other. However, there is the same service in each ensemble, for example KBS star and KBS TTI.

When performing an inter-frequency handover to a region where the ensemble is different, the DMB terminal checks whether the same service as the service currently being viewed in the serving cell 510 is served by the target cell 520.

As a result of the check, when the same service is supported by the target cell 520, the DMB terminal transitions to the frequency 11B corresponding to the target cell 520 while maintaining the service provided to the serving cell 510.

Therefore, when different ensembles and the same service identifier exist, the DMB terminal may perform handover between frequencies by using mapping information about [ensemble: frequency] and [service: ensemble].

FIG. 6 is a diagram for describing a handover method between frequencies in a case where frequencies, ensembles, and services are different from each other according to an embodiment of the present invention.

As shown in FIG. 6, it can be seen that the ensemble identifier and service identifier allocated to the 11C band of the Chungcheong region are different from the ensemble identifier and service identifier allocated to the 12C band of the Jeonbuk region.

When performing an inter-frequency handover to a region where the ensemble is different, the DMB terminal checks whether the same service as the service currently being viewed in the serving cell 610 is serviced by the target cell 620.

As a result of the check, when the same service is not supported by the target cell 620, the DMB terminal checks whether a service composed of the same service component as the currently provided service exists in the target cell 620.

As a result of the check, if there is a service configured with the same service component, the DMB terminal performs handover to the corresponding service of the target cell 620. For example, when a DMB terminal moving from Chungjeong area to Jeonbuk area receives a TV service in Chungcheong area and performs handover, it performs handover to TV service in Jeonbuk area.

Therefore, when different ensembles are present and the same service identifier exists, the DMB terminal may perform handover between frequencies using respective mapping information for [ensemble: frequency], [service: ensemble], and [service: service]. Can be.

7 is a view for explaining a link identifier allocation method for a specific road section according to an embodiment of the present invention.

Referring to FIG. 7, channel quality statistical information for each road section according to the present invention may be collected for each link identifier for identifying a specific section of the corresponding road.

The link identifier may be uniquely identified based on the start position information, the end position information, the at least one waypoint location information of the corresponding road section.

Hereinafter, a link identifier allocation method according to an embodiment of the present invention will be described in detail with reference to FIG. 7.

As shown in FIG. 7, there may be various driving paths, for example, link A 730, link B 740, and link C 750 between the starting point 710 and the ending point 720.

Therefore, link identifiers should be assigned to distinguish different paths existing between the same origin and destination. To this end, it is preferable to include information on the transit area for each possible driving route for a specific starting point and end point. The number of waypoint information existing on the route may vary depending on the type of road. For example, there may be no transit area information for roads that are straight sections, and when the route is severely changed, such as curved and S-shaped roads, at least one transit area information may be included in the channel quality information table for each road section. .

The DMB terminal according to the present invention can identify a link identifier corresponding to its current location and direction using the location information of the start and end points and the transit area information. Here, the information on the direction of the DMB terminal is TII of FIG0 / 22 included in the current location of the DMB terminal and the fast information channel, where TII is the longitude / latitude information of the corresponding DMB transmitting station and the transmission delay time. It is possible to calculate by including information about the.

Accordingly, the DMB terminal according to the present invention may check a link identifier corresponding to a driving route while driving and perform handover by using channel quality information for each frequency corresponding to the identified link identifier.

8 is a channel quality information table for each road section according to an embodiment of the present invention.

As illustrated in FIG. 8, the channel quality information table 800 for each road section includes a link identifier 810, link information 820 corresponding to the link identifier 820, a maximum speed limit 830, and a cell identifier ( 830, the frequency band 850, and measured channel quality information 860.

The link information 820 may include start position information, end position information, and waypoint information indicating the longitude and latitude of the link. Here, the waypoint information may include first to Nth waypoint information according to characteristics of the corresponding road section.

The maximum speed limit 830 is a field for recording a maximum speed limit applied to a corresponding road, and the channel quality threshold and hysteresis time for the DMB terminal to determine whether to handover according to the maximum speed limit of the corresponding road section. Here, the hysteresis time means a handover delay timer setting value that controls to continuously monitor the channel quality after the channel quality measurement recognizes the necessity of handover and before the actual handover is initiated. Differential can be applied.

For example, a faster hysteresis time may be set for a faster driving section, and thus a shorter hysteresis time may be set, and a channel quality threshold value used to determine whether to initiate a handover to a target DMB base station is also low. Can be determined at the level.

The cell identifier 840 is a field for storing a cell identifier of a mobile communication system located in a service area corresponding to the link identifier 810, and the first to Nth numbers may be mapped per corresponding link identifier. Accordingly, the DMB terminal equipped with the mobile communication function acquires cell identifier information corresponding to the access cell and the neighboring cell from the current access base station, and converts the link identifier 810 corresponding to the obtained cell identifier into the channel quality information table for each road section. You can check it by referring to

The frequency band 850 is a field for recording at least one frequency band allocated to a road section corresponding to the link identifier.

The channel quality information 860 may include an electric field strength (dBm or dBuV / m) measured through a field test, a data error rate, shadow area identification information, and the like.

The data error rate may be broken down by broadcast service type, and may include a bit error rate (BER) and a block error rate (BLER) for each service type.

The shaded area identification information compares the electric field strength and the data error rate measured in the corresponding frequency band with a preset reference value, and provides identification information for easily distinguishing whether a specific frequency band corresponding to the link identifier is a sound region. For example, as shown in FIG. 8, the shadow area identification information may be set to 'YES' for the shadow area and 'NO' for the shadow area.

According to another embodiment of the present invention, the link information 820 may further include road shape information to easily identify whether the corresponding road section is a straight section or a curved section.

In addition, according to another embodiment of the present invention, the link information 820 may further include a road number, a road name, and the like. In particular, when the DMB terminal is equipped with a navigation function, a road number or a road name can be obtained based on the driving route selected by the user and the location information of the current DMB terminal. The link identifier may be checked by referring to the channel quality information table for each road section.

Therefore, when handover is required, the DBM terminal can select the search target frequency by referring to the channel quality information table for each road section more quickly, and determine whether to perform handover to the target DMB base station by measuring the quality of the selected frequency. Can be.

The DMB terminal according to the present invention maintains a channel quality information table for each road section for the entire DMB service area according to the capacity of the internally provided memory, or based on the location of the current DMB terminal, for example, a specific region, for example, Seoul area-. It is possible to dynamically receive a channel quality information table for each road section about through a return channel.

For example, the DMB terminal currently maintains service area information of the channel quality information table for each road section, where the service area information may include a latitude range and a longitude range, and the current location information and the moving direction. It is possible to determine whether the channel quality information table for each road section corresponding to the new service area is needed. According to the determination result, the channel quality information table for each road section suitable for the current position and the moving direction is obtained from the DMB station through the return channel. Can be received.

9 is a flowchart illustrating a procedure for performing handover in a DMB terminal according to an embodiment of the present invention.

Referring to FIG. 9, the DMB terminal maintains a channel quality information table for each road section in a predetermined recording area (S902).

The DMB terminal decodes the broadcast channel to obtain service relationship information for the corresponding service area and stores it in a predetermined recording area (S904).

The DMB terminal measures the channel quality of the service currently being viewed (S906), and compares whether the measured channel quality satisfies a predetermined channel quality threshold value (S908).

As a result of the comparison, if it is not satisfied, the DMB terminal measures its current location using the GPS receiving module (S910), and selects the highest priority search target channel using the measured location and the channel quality information table for each road section ( S912).

The DMB terminal measures channel quality for the selected channel (S914), and checks whether the measured channel quality satisfies a predetermined channel quality threshold for handover (S916).

As a result of the check, the DMB terminal performs the handover to the selected channel (S918).

If the quality of the selected channel does not satisfy the predetermined channel quality threshold in step 916, the DMB terminal selects a frequency band having the next higher channel quality by referring to the channel quality information table for each road section ( S920), the above step 914 is performed.

According to another embodiment of the present invention, the current position of the DMB receiver is TII contained in FIG0 / 22, where the TII includes longitude / latitude information and transmission delay time information of the corresponding DMB transmitting station. It is possible to estimate their position or to calculate the direction of movement.

Therefore, it should be noted that the DMB receiver according to the present invention can estimate its current position and direction of movement without mounting a separate GPS receiver module. In the current DMB system, basic information for handover may be repeatedly transmitted through a fast information channel (FIC) configured with a fast information group (FIG).

In particular, FIG. 0/22 transmits TII database information, and the DMB receiver may decode FIB Type 0/22 to acquire longitude / latitude coordinate information and transmission delay time information of the corresponding DMB transmitter. However, FIG Type 0/22 has a feature of selectively transmitting information in a DMB system.

According to another embodiment of the present invention, when the DMB receiver is equipped with a mobile communication function, for example, at least one of communication functions such as CDMA / GSM / WCDMA, the current location of the DMB terminal is currently connected. It can be estimated using the cell identifier of the base station.

In order to facilitate retrieval of the link identifier corresponding to the cell identifier, as shown in FIG. 8, the channel quality information table for each road section according to the present invention may include at least one cell identifier corresponding to the corresponding link identifier. It may be.

In this case, the DMB receiver may identify the link identifier corresponding to the cell identifier received from the access base station with reference to the channel quality information table, and perform the DMB handover using the channel quality information corresponding to the link identifier. .

10 is a flowchart illustrating a search procedure for handover according to an embodiment of the present invention.

In more detail, FIG. 10 is a diagram for describing a detailed procedure corresponding to reference numeral 930 of FIG. 9.

Referring to FIG. 10, the DMB terminal selects a link identifier corresponding to the measured position with reference to the channel quality information table for each road section (S1002).

The DMB terminal selects a frequency having the best channel quality corresponding to the link identifier with reference to the channel quality information table for each road section (S1004).

The DMB terminal extracts service relationship information corresponding to the selected frequency (S1006), and checks whether the continuity of the currently viewed service can be supported through the selected frequency with reference to the extracted service relationship information (S1008).

As a result of the check, if the continuity of the service can be supported, the DMB terminal measures the channel quality for the selected frequency (S1010), and checks whether the measured channel quality satisfies a preset channel quality threshold value corresponding to the handover. (S1012).

As a result of the check, the DMB terminal performs the handover to the selected channel (S1014).

If it is not possible to support the continuity of the service currently being viewed through the frequency selected in step 1008, the DMB terminal selects a frequency having the next higher channel quality with reference to the channel quality information table for each road section (S1016). Perform step 1006.

In addition, if the channel quality measured in step 1012 does not satisfy the predetermined channel quality threshold value, the DMB terminal selects a frequency having the next higher channel quality with reference to the channel quality information table for each road section (S1016), Step 1006 described above is performed.

As described above with reference to FIGS. 9 and 10, the DMB terminal according to the preferred embodiment of the present invention identifies a search target frequency for handover using a channel quality information table and service relationship information for each road section, The frequency search order may be determined using the measured channel quality information for each frequency.

In addition, the DMB terminal may perform handover to a channel capable of supporting the continuity of the service currently being viewed using the service relationship information.

That is, the DMB terminal according to the present invention has an advantage of performing a faster and more efficient handover between frequencies.

11 is a functional block diagram of a digital broadcast receiving apparatus according to an embodiment of the present invention.

As shown in FIG. 11, the digital broadcasting receiver (DMB terminal) according to an embodiment of the present invention includes a wireless interface unit 1110, a quality measuring unit 1120, a control unit 1130, and a service continuity determining unit 1140. ), The service relationship information storage unit 1150, the location acquisition unit 1160, the search frequency selection unit 1170, the channel quality information storage unit 1180 for each road section, and the playback unit 1190. have.

The wireless interface unit 1110 performs functions such as modulation and demodulation of a radio signal, signal amplification, data encoding and decoding, data multiplexing and demultiplexing, data error check, and reception signal field strength measurement. Can be.

For example, the wireless interface unit 1110 receives a GPS signal from the GPS satellite 1191 to calculate current location information of the DMB terminal, and receives a DMB broadcast channel transmitted by the DMB base station 1192 to provide service relationship information. And extracting location information and transmission delay time information of the DMB base station, extracting a cell identifier of a currently connected base station and a cell identifier of a neighboring base station by decoding a control signal transmitted by the mobile communication base station 1193, and a return channel. Through this, a function of acquiring channel quality information for each road section may be performed.

The quality measuring unit 1120 compares the received electric field strength of the DMB broadcast signal measured by the wireless interface unit 1110 with a channel quality threshold value, which is a predetermined reference value for determining whether to start the handover procedure, and starts the handover procedure. A predetermined control signal (hereinafter, referred to as a handover start request signal) may be provided to the controller 1130.

In addition, the quality measuring unit 1120 measures the channel quality for a specific frequency according to the control signal of the control unit 1130 and compares the measured channel quality information with a predefined handover quality reference value to hand over the measured channel. It may be determined whether the channel is suitable for, and the determination result may be provided to the controller 1130.

The quality measuring unit 1120 according to another exemplary embodiment of the present invention calculates a data error rate (eg, includes BER and BLER) by using the data error check result, and the calculated data error rate corresponds to a predetermined criterion. The controller 1130 may provide the handover initiation request signal to the controller 1130 by determining whether it is satisfied.

The controller 1130 may control the search frequency selector 1170 to perform a frequency search according to the handover start request signal received from the quality measurer 1120.

The search frequency selector 1170 identifies the link identifier corresponding to the current location by referring to the channel quality information stored in the channel quality information storage unit 1180 for each road section according to a control signal of the controller 1130, and identifies the identified link identifier. The search target frequency may be selected from among at least one frequency corresponding to. Thereafter, the search frequency selector 1170 may assign a search priority to the selected frequency.

The position acquiring unit 1160 may provide basic information necessary for calculating the current position of the DMB terminal from the wireless interface unit 1110—for example, latitude and longitude information of the DMB terminal, latitude and longitude information of the DMB base station, transmission delay time information, And include at least one of cell identifier information, and calculate or estimate current location information of the DMB terminal using the collected basic information. In addition, the location acquisition unit 1160 may provide the search frequency selection unit 1170 with current location information of the DMB terminal calculated or estimated at the request of the search frequency selection unit 1170.

The service continuity verification unit 1140 determines whether the search target frequency selected by the search frequency selection unit 1170 according to the control signal of the controller 1130 can support the continuity of the service currently being viewed. Performs the function of judging with reference to).

Referring to FIG. 11, the wireless interface unit 1110 stores a service relationship information obtained from a DMB broadcasting channel in a service relationship information storage unit 1150 and a channel quality information table for each road section obtained through a return channel. The channel quality information storage unit 1180 for each road section may be stored.

The controller 1130 according to the present invention performs a resource allocation and scheduling function, data and message processing function, etc. in the DMB terminal. In particular, the controller 2230 performs an overall process flow control function for handover.

The playback unit 1190 plays the user data received from the control unit 1190, where the user data includes audio, video, packet data, and the like.

Embodiments of the present invention include computer readable media containing program instructions for performing various computer-implemented operations. The computer readable medium may include program instructions, local data files, local data structures, or the like, alone or in combination. The media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts.

Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical recording media such as CD-ROMs, DVDs, magnetic-optical media such as floppy disks, and ROM, RAM, flash memory, and the like. Hardware devices specifically configured to store and execute the same program instructions are included.

The medium may be a transmission medium such as an optical or metal wire, a waveguide, or the like for transmitting a signal specifying a program command, a local data structure, or the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like.

Preferred embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art will be able to make various modifications, changes, and additions within the spirit and scope of the present invention. Additions should be considered to be within the scope of the following claims.

1 is a DMB network structure for explaining a method for performing a handover by using the channel quality information for each road section according to an embodiment of the present invention.

2 is a frequency allocation example of a DMB service according to an embodiment of the present invention.

3 is a view for explaining a DMB frequency allocation method according to an embodiment of the present invention.

4 is a diagram for explaining inter-frequency handovers for the same ensemble according to one embodiment of the present invention;

5 is a diagram for explaining inter-frequency handovers for different ensembles according to one embodiment of the present invention;

FIG. 6 is a diagram for explaining a handover method between frequencies for a case where frequencies, ensembles, and services are different from each other according to an embodiment of the present invention; FIG.

7 is a view for explaining a link identifier allocation method for a specific road section according to an embodiment of the present invention.

8 is a channel quality information table for each road section according to an embodiment of the present invention.

9 is a flowchart illustrating a procedure for performing handover in a DMB terminal according to an embodiment of the present invention.

10 is a flowchart illustrating a search procedure for handover according to an embodiment of the present invention.

11 is a functional block diagram of a digital broadcast receiving apparatus according to an embodiment of the present invention.

* Key Drawing

800: Channel quality information table for each road section

810 link identifier

820: link information

830: maximum speed limit

840 cell identifier

850: frequency band

860: measured channel quality information

1120: quality measuring unit

1130: control unit

1140: Service Continuity Determination Unit

1150: service relationship information storage unit

1160: position acquisition unit

1170: search frequency selector

1180: Channel quality information storage unit for each road section

Claims (18)

Maintaining channel quality information for each road section for maintaining channel quality information for each road section in a predetermined recording area; A service quality checking step of checking whether a channel quality for a current service channel satisfies a preset channel quality threshold value; A search target channel selection step of selecting a search target channel for handover with reference to the channel quality information for each road section, if not satisfied; And Performing a handover according to the channel quality of the selected discovery target channel A method for performing handover in a digital broadcast reception device comprising a. The method of claim 1, The channel quality information for each road section A link identifier for uniquely identifying a unit road segment; Link information corresponding to the link identifier; First to Nth frequency information allocated to a service area corresponding to the link identifier; And Channel quality information measured according to the allocated frequency A method for performing handover in a digital broadcast reception device comprising at least one of the following. The method of claim 2, And wherein the link information includes at least one of start position information, end position information, and waypoint location information of a road section corresponding to the link identifier. The method of claim 3, The link information further comprises at least one of a road number and a road name corresponding to the corresponding link identifier. The method of claim 2, The channel quality information for each road section First to N-th cell identifiers of mobile communication base stations included in a service area corresponding to the link identifier The method of performing handover in a digital broadcast receiving apparatus further comprising a. The method of claim 2, The channel quality information for each road section The apparatus further includes driving maximum speed limit information of a road section corresponding to the link identifier, wherein a handover start time and a quality measurement reference value for a handover target channel are set differently according to the driving maximum speed limit. Method for performing handover in a broadcast receiving device. The method of claim 2, The measured channel quality information includes at least one of electric field strength, received data error rate, and shadow area identification information of a received channel. The method of claim 2, The searching channel selection step Measuring a current position and a moving direction of the digital broadcast reception device; Selecting a link identifier corresponding to the measured current position and moving direction with reference to the link information; And Determining a frequency search order using channel quality information for each frequency corresponding to the link identifier; A method for performing handover in a digital broadcast receiving apparatus comprising a. The method of claim 8, The searching channel selection step And determining whether a service channel capable of supporting the continuity of the current service channel exists on the corresponding frequency by referring to the service relationship information stored in advance according to the determined frequency search order. How to perform handover in. The method of claim 8, The searching channel selection step If the channel quality for each frequency is below a predetermined criterion, the method further comprises the step of excluding the frequency from the search target. The method of claim 8, The current position and direction of movement of the digital broadcast receiver A method for performing handover in a digital broadcast receiver, characterized in that the signal is measured by decoding one of a fast information channel received from a digital broadcast transmitter, a control signal received from a mobile communication base station, and a GPS signal. A recording medium readable by an electronic device on which a program consisting of typed instructions for executing a handover method in a digital broadcast receiving device, Maintaining channel quality information for each road section for maintaining channel quality information for each road section in a predetermined recording area; A service quality checking step of checking whether a channel quality for a current service channel satisfies a preset channel quality threshold value; A search target channel selection step of selecting a search target channel for handover with reference to the channel quality information for each road section, if not satisfied; And Performing a handover according to the channel quality of the selected discovery target channel And a program for executing a method for performing a handover in a digital broadcast receiving apparatus. A storage unit for maintaining channel quality information and service relationship information for each road section; A search frequency selection unit for determining a search order of a handover target frequency by using a current position of the digital broadcasting receiver and channel quality information of each road section; A service continuity judging unit verifying whether the frequency to be searched can support the service continuity of the current service channel with reference to the service relationship information; And Quality measurement unit that determines whether to initiate the handover by measuring the quality of the DMB signal Digital broadcast receiving device comprising a. The method of claim 13, The service relationship information is a digital broadcast receiver, characterized in that the mapping relationship between the ensemble, frequency and service is defined. The method of claim 13, And a position obtaining unit which measures at least one of a current position and a moving direction of the digital broadcast receiving unit and provides the measured position to the search frequency selection unit. The method of claim 13, The channel quality information for each road section A link identifier for uniquely identifying a road segment; Link information including at least one of start position information, end position information, and waypoint location information of a road section corresponding to the link identifier; First to Nth frequency information allocated to a road section corresponding to the link identifier; And Channel quality information measured according to the allocated frequency Digital broadcast receiving device comprising at least one of. The method of claim 16, The channel quality information for each road section further includes first to N-th cell identifiers of mobile communication base stations that provide mobile communication services for road sections corresponding to the link identifier. The method of claim 13, And the channel quality information for each road section is received from an access mobile communication base station through a predetermined broadcast return channel.

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