KR20090090042A - Data terminal and handover method for the same - Google Patents

Abstract

An information terminal equipped with a DMB receiving module and a handover method therefore are provided to connect the information terminal to a channel transmitting the broadcasting signal automatically in case that the information terminal equipped with the DMB receiving module. A handover determiner(1610) determines whether to drive a handover module according to the necessity of the handover. A location calculation unit(1620) uses a GPS(Global Positioning System) receive module as the hand over module. The current position of the information terminal is measured. A candidate extracting unit(1640) extracts DMB(Digital Multimedia Broadcasting) transmitting stations which are adjacent to the information terminal with reference to the result of computation of the distance measuring unit. A transmitting station determining unit(1650) selects the hand over object DMB transmitting station based on distance between the information terminal and the DMB transmitting station.

Description

Data terminal and handover method for the same {Data Terminal and Handover Method for the Same}

The present invention relates to an information terminal, and more particularly, to an information terminal and a handover method for continuously receiving traffic information transmitted from a digital multimedia broadcasting (DMB) transmission station even when a boundary between regions is moved.

Recently, a technology for providing a traffic and travel information (TTI) service using a DMB broadcast signal has been commercialized, and this information is transmitted through a TPEG (Transport Protocol Expert Group) protocol.

The TPEG standard is a standardized state of Road Traffic Message (RTM), Public Transport Information (PTI), etc., and is used to map the road to be driven on the map of the navigation terminal with DMB reception function. Traffic conditions or traffic speeds may be indicated, and the user may be informed in advance of danger section information such as road construction and accident news.

While the existing navigation service simply informs the shortest route based on the map information already stored, the TPEG service is an intelligent route guidance service in that it provides the optimal route by reflecting road conditions and speed information in real time. have.

Such a TPEG service is generally provided in connection with a navigation service. To this end, a recently released navigation terminal is equipped with a DMB receiving module. In addition, portable information terminals such as cellular phones, personal communication service (PCS) phones, personal digital assistants (PDAs), and portable multimedia players (PMPs) are also equipped with DMB receiving modules to provide users with a wider range of services. have.

Meanwhile, in the DMB system, the same broadcast content is transmitted through different channels for different regions. Therefore, when the information terminal receiving a specific DMB broadcast moves the boundary between regions, the signal strength from the previously connected broadcasting station is weak and the broadcast signal is disconnected. Accordingly, even the TPEG service served with the corresponding broadcast signal is interrupted. Will be.

Therefore, the user is inconvenient to change the channel directly in order to continue using the traffic information service through the TPEG. In addition, there is a problem that an accident risk increases while manually changing a channel.

On the other hand, recently, when a broadcast signal is transmitted from a DMB transmitting station to a DMB module, a method of preparing for handover by transmitting neighboring station information together has been proposed. However, in this case, the size of the broadcast signal is unnecessarily increased because the handover-related information must be received from the transmitting station currently connected.

The present invention has been made to solve the above-mentioned disadvantages and problems, an information terminal having a DMB receiving module that can be automatically connected to a channel for transmitting a broadcast signal that is already received when moving the boundary between regions and for There is a technical problem in providing a handover method.

Another technical problem of the present invention is to provide an information terminal having a DMB receiving module moving between borders, and to determine a transmitting station to be reconnected based on a distance from an adjacent DMB transmitting station, thereby enabling an TPEG service to be seamlessly used. It is to provide a handover method for this.

An information terminal according to an embodiment of the present invention for achieving the above-described technical problem is a DMB broadcast signal including a TPEG (Transport Protocol Expert Group) signal from a Global Positioning System (GPS) receiving module and a Digital Multimedia Broadcasting (DMB) transmitting station. An information terminal each connected to a DMB receiving module for receiving a data, comprising: a memory in which the respective DMB transmitting station information is stored; And when the handover is necessary, searching for at least one DMB transmitting station adjacent to the information terminal among the DMB transmitting stations transmitting the same signal as the currently received DMB broadcasting by referring to the DMB transmitting station information, and searching for the at least one adjacent neighbor. And a handover module for selecting a handover target DMB transmitting station based on a distance between the DMB transmitting station and the information terminal.

Meanwhile, a handover method for an information terminal according to an embodiment of the present invention includes a DMB broadcast signal including a TPEG (Transport Protocol Expert Group) signal from a global positioning system (GPS) receiving module and a digital multimedia broadcasting (DMB) transmitter. A handover method in an information terminal connected to a receiving DMB receiving module, the method comprising: a first step of storing the DMB transmission information; If it is determined that handover is necessary, measuring a current position of the information terminal; A third step of calculating a distance from the at least one DMB transmitting station transmitting the same signal as the currently received DMB broadcasting to the information terminal with reference to the DMB transmitting station information; A fourth step of selecting a handover target DMB transmitting station by referring to the calculation result of the third step; And a fifth step of switching access to the DMB transmission station selected in the fourth step.

According to the present invention, even when an information terminal having a DMB receiving module changes a channel of a broadcast signal by moving a boundary between regions, handover can be automatically performed through a channel automatic search and change function.

Accordingly, there is an advantage that the TPEG service can be used seamlessly, so that the optimized route guidance can be performed in the information terminal providing the navigation service.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 is a view for explaining a handover concept to which the present invention is applied.

Referring to Fig. 1, information terminal 10 receives a broadcast signal transmitted from DMB transmitting station # 11 20 in area A. By the way, when the information terminal 10 moves from the area A to the area B, the broadcast signal transmitted from the transmission station # 11 (20) becomes weak, and if the distance from the transmission station # 11 (20) continues to move away, the broadcast signal eventually becomes. Will hang up.

Therefore, the information terminal 10 searches for the transmitting station # 12 (22), the transmitting station # 13 (24), the transmitting station # 14 (26), and the transmitting station # 15 (28) in the area B after the movement, Among these, a handover procedure is performed to select the optimal transmission station (the nearest transmission station) to reconnect considering the distance from itself.

At this time, the information terminal 10 can determine the handover target transmission station in consideration of the signal strength from the neighboring transmission station in addition to the distance from the neighboring transmission station. 10 may be determined by weighting the distance to 10). In this case, it is possible to prevent the occurrence of a situation in which handover is temporarily required and a handover is required again.

To this end, the information terminal 10 of the present invention is equipped with a GPS receiving module. In addition, the information terminal 10 stores station location information (latitude / longitude coordinates (GPS coordinates)) for each broadcast signal, channel information assigned to each transmission station, and the like. When handover is required, the information terminal 10 refers to its own location information and the location information (latitude / longitude coordinates) of the transmitting station that transmits the previously received broadcast signal, and the plurality of information terminals 10 adjacent to the information terminal 10. Search for the source. Subsequently, a handover is performed by selecting a transmission station closest to the information terminal 10 among the searched neighboring transmission stations.

In another embodiment of the present invention, the information terminal 10 measures the broadcast signal strength from a plurality of searched neighboring transmitters, weights the distance with the information terminal 10, and transmits the transmitter having the most optimal communication state. Select to connect to the relevant station.

For example, the information terminal 10 moving to the area B searches for four neighboring transmission stations 22, 24, 26, 28 with reference to its location and location information of the broadcast signal transmission station which is already received. The distance between the transmitting stations 22, 24, 26, 28 and the information terminal 10 can be calculated to perform a handover to the nearest transmitting station.

For more accurate handover, the signal strength from the transmitting station may be considered. For this purpose, the information terminal 10 measures the broadcast signal strength transmitted from the searched transmitting stations 22, 24, 26, 28 to the information terminal 10. do. For example, the broadcast signal strength may be in the order of transmission # 13 (24)> transmission # 12 (22)> transmission # 14 (26)> transmission # 15 (28).

Although the transmission target may be selected based only on the measured broadcast signal strength, it is preferable to further consider the distance to the information terminal 10 for more accurate transmission selection.

That is, when the signal strength from the neighboring transmission station is measured, the optimal broadcast station is selected by assigning a distance weight to the measured broadcast signal, and then connected to the corresponding transmission station to use the broadcast signal and the TPEG service included therein. The distance between the information terminal 10 and the transmitting station may be, for example, transmitting station # 13 (24)> transmitting station # 12 (22)> transmitting station # 15 (28)> transmitting station # 14 (26). Selects transmission station # 13 (24) as the handover target transmission station.

As described above, in the present invention, when the information terminal using the TPEG service moves between regions through the DMB broadcast signal, the neighboring transmitting station is searched for in the region after the movement, and the broadcast signal strength from the neighboring transmitting station and the information terminal and the neighboring transmitting station are moved. By changing the connection to the selected transmission station based on the distance between them, the TPEG service can be continuously used.

2 is a block diagram of an information terminal according to an embodiment of the present invention.

As shown, the information terminal 10 according to the present invention includes a control unit 110, a memory 120 and a handover module 160, the GPS receiving module 140 and the DMB receiving module 150 is built-in Or it may be mounted externally. In addition, when the information terminal 10 is a navigation terminal, in particular, a navigation module 130 for route calculation and guidance is additionally mounted.

More specifically, the controller 110 controls the overall operation of the information terminal 10, and the memory 120 stores station location information (latitude / longitude coordinates) for each broadcast signal, channel information assigned to each transmitter, and the like. have. If the information terminal 10 is a navigation terminal, the memory 120 additionally stores information necessary for route calculation and guidance such as road information, map information, and main feature information.

As the starting and destination information is set by the user, the navigation module 130 generates route information using road information stored in the memory 120 and provides the same to the user.

In addition, the GPS receiving module 140 receives satellite orbit information and pseudo range (PR) information from a GPS satellite (not shown) to calculate a current position of the vehicle, and the DMB receiving module 150 controls the controller 110. ) Is tuned to the DMB transmission station to receive the broadcast signal and the TPEG signal transmitted with it.

On the other hand, the handover module 160 is driven when the handover is necessary, and calculates a distance from itself by referring to the location information of the transmission station for each broadcast signal stored in the memory 120. Then, one of the plurality of transmitting stations adjacent to the terminal (the nearest transmitting station) is selected to perform a handover.

In another embodiment of the present invention, the handover module 160 may determine the handover target transmitter according to the distance between the plurality of adjacent transmitters and the information terminal 10 and the signal strength from the neighboring transmitter to the information terminal 10. Do.

At this time, in order to more accurately determine the handover target station, the handover target station can be selected by measuring the signal strength from the selected neighboring station a plurality of times and calculating an average value, and the signal strength from the selected neighboring station (or the average thereof). By assigning the distance to the information terminal 10 as a weight, it is possible to prevent the signal reception state from being temporarily connected to the transmission station.

3 is a detailed configuration diagram of the handover module shown in FIG. 2.

As shown, the handover module 160 includes a handover determiner 1610, a position calculator 1620, a distance measurer 1630, a candidate extractor 1640, a transmitter determiner 1650, and a connection switchover. A portion 1660 is included.

A detailed description of each component is as follows.

First, the handover determination unit 1610 may specify a time when the strength of a broadcast signal received by the DMB receiving module 150 is less than or equal to a preset threshold or a state in which the strength of the broadcast signal is less than or equal to a preset threshold (for example, 2 minutes), it is determined that the handover is necessary to drive the handover module 160.

Accordingly, the position calculating unit 1620 receives satellite orbit information and PR information from the GPS satellites to measure the current position of the information terminal 10, and the distance measuring unit 1630 is a transmission station information table (in the memory 120) 1210, the distance from the information terminal 10 to each transmitting station is calculated.

The candidate extractor 1640 extracts, as a candidate, a plurality of transmission stations (for example, four) adjacent to the information terminal 10 with reference to the calculation result of the distance measuring unit 1630.

Next, the transmitter determining unit 1650 selects any one of the plurality of transmitting stations extracted by the candidate extracting unit 1640 as the handover target transmitting station, and the connection switching unit 1660 determines that the DMB receiving module 150 determines the transmitting station determining unit ( Tune to a transmission station selected in step 1650 to receive the broadcast signal and the TPEG signal.

Here, the transmitter determiner 1650 determines the nearest transmitter to which the information terminal 10 can connect among the plurality of transmitters extracted by the candidate extractor 1640 as the handover target transmitter, or the candidate extractor 1640. The transmission station having the highest signal strength transmitted from each of the extracted plurality of transmission stations to the information terminal 10 is determined as the handover target transmission station, or is transmitted from each of the plurality of transmission stations extracted by the candidate extraction unit 1640 to the information terminal 10. The distance between the information terminal 10 and the transmitting station may be weighted to the signal strength to determine the handover target transmitting station.

Here, the accuracy can be further improved when the signal strength from each transmission station is measured a plurality of times and the handover target transmission station is determined based on the average value. In addition, if the distance from the information terminal 10 is applied to the signal strength from each transmission station or the average thereof as a weight, an error of handover to the transmission station with a good signal strength temporarily can be prevented.

4 is an exemplary diagram of a transmitter information table applied to the present invention.

As shown, the memory 120 includes a transmitter information table 1210 including a transmitter identifier for identifying each transmitter installed in each region, latitude / longitude coordinate values as location information, channel information assigned to each transmitter, and the like. It is built. Accordingly, when handover is required, the distance measuring unit 1630 of the handover module 160 may calculate the distance from the information terminal 10 to the transmitting station that transmits the corresponding broadcast signal when referring to the transmitting station information table 1210. Can be. In addition, the DMB receiving module 150 may tune to the corresponding transmission station by referring to the channel information of the transmission station determined as the handover target.

Such a table 1210 may be updated through a predetermined field of the DMB broadcast signal when the source information is added, changed, or deleted, so that the information terminal 10 may always maintain the source information in a new state.

Next, the handover method of the information terminal described above will be described with reference to FIGS. 5 to 7.

5 is a flowchart illustrating a handover method according to an embodiment of the present invention.

First, the handover determination unit 1610 continuously monitors the strength of the broadcast signal received by the DMB receiving module 150, so that when the handover is necessary, that is, the strength of the broadcast signal received by the DMB receiving module 150. If it is less than or equal to a preset threshold, or if the strength of the broadcast signal is less than or equal to the preset threshold for a specified time (for example, 2 minutes), the handover module 160 is determined to be a situation that requires handover. Drive (S101).

Accordingly, the position calculator 1620 measures the current position of the information terminal 10 (S103), and the distance measurer 1630 is currently receiving a broadcast signal through the transmission station information table 1210 in the memory 120. The location information of the other transmitting station which transmits the data is inquired, and the distance from the information terminal 10 is calculated (S105).

Subsequently, the candidate extracting unit 1640 and the transmitting station determining unit 1650 are a distance from each transmitting station to the information terminal 10 or a distance from each transmitting station to the information terminal 10 and from each transmitting station to the information terminal 10. The handover target transmission station is selected based on the strength of the transmitted broadcast signal (S107).

When the transmitter determiner 1650 determines the handover target transmitter using only the distance between the transmitter and the information terminal 10, step S107 is a process of determining the nearest transmitter that can be connected to the information terminal 10. .

On the other hand, when the transmitter determiner 1650 considers the reception address strength in addition to the distance between the transmitter and the information terminal 10, a process of determining a target station for handover is specifically illustrated in FIGS. 6 and 7.

That is, as shown in FIG. 6, the candidate extracting unit 1640 extracts a plurality of candidate transmitting stations based on the calculation result of step S105 (S201). Subsequently, the transmitter determiner 1650 measures the strength of each broadcast signal transmitted from the candidate transmitters extracted in step S201 to the information terminal 10 (S203), and determines the priority based on the measured signal strength ( S205) With reference to the priority, one of the transmitters is determined as the handover target transmitter.

In addition, in a preferred embodiment of the present invention, the signal strength measurement process (S203) of Figure 6 may be performed as shown in FIG.

That is, in order to measure the signal strength a plurality of times for each of the plurality of transmission stations extracted as candidates in step S201, the signal strength measurement count count is started (S301), and it is checked whether the measurement number exceeds the preset number (S303). If the number of times of measurement as a result of the check in step S303 does not exceed the preset number, the signal strength transmitted from the corresponding transmitting station to the information terminal 10 is measured, and the flow proceeds to step S301 to measure the signal strength by the preset number of times.

If the number of times of measurement in step S303 is greater than or equal to the preset number, that is, after the signal strength measurement is completed by the preset number of times, the average value of the measured signal strengths is calculated (S307), and the flow proceeds to step S205.

In the preferred embodiment of the present invention, after determining the priority in step S205 and then weighting the distance between the information terminal 10 and the transmitter measured in step S105, the handover target transmitter can be determined more accurately. .

Referring back to FIG. 5, after the handover target transmission station is selected in step S107, the channel information of the corresponding transmission station is provided to the DMB receiving module 150 so that the DMB receiving module 150 tunes to the handover target transmission station. (S109).

In this way, the DMB receiving module 150 seamlessly receives the DMB broadcast signal and the TPEG traffic information from the newly connected transmitting station.

As such, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof. Therefore, the above-described embodiments are to be understood as illustrative in all respects and not as restrictive. The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

According to the present invention, an information terminal receiving traffic and travel information (TTI) from a DMB broadcasting station can automatically switch channels even when traveling between regions, so that continuous TTI reception can be achieved. It becomes possible.

Therefore, the information terminal can provide an optimal path reflecting the TTI, thereby improving the service satisfaction of the navigation terminal, thereby increasing revenue generation.

1 is a view for explaining a handover concept to which the present invention is applied,

2 is a block diagram of an information terminal according to an embodiment of the present invention;

3 is a detailed configuration diagram of the handover module shown in FIG. 2;

4 is an exemplary diagram of a transmitter information table according to the present invention;

5 is a flowchart illustrating a handover method according to an embodiment of the present invention;

6 is a detailed flowchart of a transmission station selection process shown in FIG. 5;

FIG. 7 is a detailed flowchart of the signal strength measurement process of FIG. 6.

<Description of the symbols for the main parts of the drawings>

10: information terminal 110: control unit

120: memory 130: navigation module

140: GPS receiving module 150: DMB receiving module

160: handover module 1610: handover determination unit

1620: position calculation unit 1630: distance measurement unit

1640: candidate extracting unit 1650: transmitting station determining unit

1660: connection switching unit 1210: transmission station information table

Claims (17)

An information terminal connected to a global positioning system (GPS) receiving module and a DMB receiving module for receiving a DMB broadcasting signal including a TPEG (Transport Protocol Expert Group) signal from a digital multimedia broadcasting (DMB) transmitting station. A memory in which the respective DMB source information is stored; And When a handover is necessary, the at least one DMB transmitting station adjacent to the information terminal is searched among the DMB transmitting stations transmitting the same signal as the currently received DMB broadcasting by referring to the DMB transmitting station information, and the searched at least one neighboring DMB. A handover module for selecting a handover target DMB transmitting station based on a distance between the transmitting station and the information terminal; Information terminal comprising a. The method of claim 1, The handover module may include a handover determination unit configured to determine whether to drive the handover module according to whether handover is required; A position calculator configured to measure a current position of the information terminal using the GPS receiver module as the handover module is driven; A distance for calculating a distance from the DMB transmitting station transmitting the same signal as the currently received DMB broadcasting to the information terminal by referring to the current position of the information terminal measured by the position calculating unit and the DMB transmitting information for each DMB broadcasting signal. Measuring unit; A candidate extracting unit extracting at least one DMB transmitting station adjacent to the information terminal with reference to a calculation result of the distance measuring unit; A transmitter determining unit for selecting a handover target DMB transmitting station based on a distance between the at least one DMB transmitting station extracted by the candidate extracting unit and the information terminal; And A connection switching unit transmitting information on the DMB transmission station selected by the transmission source determining unit to the DMB receiving module to request tuning; Information terminal comprising a. The method according to claim 1 or 2, The handover module measures signal strength from each of the at least one DMB transmission station adjacent to the information terminal to the information terminal, and refers to distance information from each of the at least one DMB transmission station adjacent to the information terminal to the information terminal. Wherein the distance information is weighted to the received signal strength from each of the at least one DMB transmission station adjacent to the information terminal to select the DMB transmission target to be handed over. The method according to claim 1 or 2, The handover module measures a plurality of times the received signal strength from each of the at least one DMB transmitting station adjacent to the information terminal to the information terminal and calculates an average value, and calculates an average value from each of the at least one DMB transmitting station adjacent to the information terminal. An information terminal characterized in that a handover target DMB transmission station is selected by weighting the distance information to the average value with reference to the distance information to the information terminal. The method of claim 2, The handover determining unit, when the strength of the broadcast signal received by the DMB receiving module is less than a predetermined threshold value information terminal, characterized in that for driving the handover module. The method of claim 2, The handover determining unit, when the strength of the broadcast signal received by the DMB receiving module is maintained for a predetermined time in a state less than a predetermined threshold value, characterized in that for driving the handover module. The method of claim 1, Each DMB transmitting station information for transmitting the DMB broadcasting signal includes a transmitter identifier for identifying each DMB transmitting station, location information of each DMB transmitting station, and channel information allocated to each of the DMB transmitting stations. . The method of claim 7, wherein The information terminal of the said DMB transmission station is latitude and longitude coordinates, The information terminal characterized by the above-mentioned. A handover method in an information terminal connected to a global positioning system (GPS) receiving module and a DMB receiving module for receiving a DMB broadcast signal including a TPEG (Transport Protocol Expert Group) signal from a digital multimedia broadcasting (DMB) transmitting station, A first step of storing the DMB source information; If it is determined that handover is necessary, measuring a current position of the information terminal; A third step of calculating a distance from the at least one DMB transmitting station transmitting the same signal as the currently received DMB broadcasting to the information terminal with reference to the DMB transmitting station information; A fourth step of selecting a handover target DMB transmitting station by referring to the calculation result of the third step; And A fifth step of switching access to the DMB transmission station selected in the fourth step; Handover method using an information terminal comprising a. The method of claim 9, And said fourth step is a step of selecting a nearest DMB transmitting station accessible to said information terminal as a handover target DMB transmitting station. The method of claim 9, The fourth step, A step 4-1 of extracting at least one candidate DMB transmission station adjacent to the information terminal with reference to the calculation result of the third step; A step 4-2 of measuring received signal strength from each candidate DMB transmitting station extracted in step 4-1 to the information terminal; And A fourth step of determining a handover target DMB transmitting station by referring to the measurement result of the fourth step; Handover method for an information terminal comprising a. The method of claim 11, Step 4-2 is a step of calculating the average value by measuring the received signal strength from each candidate DMB transmitting station to the information terminal a specified number of times, Step 4-3 is a step of determining a handover target DMB transmitting station with reference to the average value. The method according to claim 11 or 12, Step 4-3 is a step of determining a handover target DMB transmission station by weighting the distance from each of the candidate DMB transmission stations to the information terminal according to the result of step 4-2. Handover method for a terminal. The method of claim 9, The second step is a handover method for an information terminal, characterized in that it is determined that the handover is necessary when the signal strength received by the DMB receiving module is less than a predetermined threshold value. The method of claim 9, The second step is a handover method for an information terminal, characterized in that if the signal strength received by the DMB receiving module is maintained at a state below a predetermined threshold for a specified time, handover is necessary. . The method of claim 9, Each DMB transmitting station information for transmitting the DMB broadcasting signal includes a transmitter identifier for identifying each DMB transmitting station, location information of each of the DMB transmitting stations, and channel information allocated to each of the DMB transmitting stations. Handover method for The method of claim 16, The location information of each of the DMB transmitting stations is latitude and longitude coordinates.

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