JP2009253628A - Content data transmitting system and transmitting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a content data transmitting system for transmitting, to the service area of predetermined areas, content data which are received by a portable type mobile terminal and are viewable. <P>SOLUTION: A plurality of transmitting apparatuses 200 are provided, which are disposed at a plurality of positions in a service area. Each transmitting apparatus 200 includes: a data reader for sequentially reading data of contents to be distributed for a portable type mobile terminal within the service area; a transmission processor which performs transmission processing for converting content data read by the data reader into a radio wave signal; an antenna for transmitting the radio wave signal processed by the transmission processor. The transmission processor includes a transmission synchronization processing section for synchronizing timing to transmit the content data for all the transmitting apparatuses. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a content data transmission system and a transmission apparatus.
Specifically, the present invention relates to a content data transmission system that transmits content for a mobile device (portable mobile terminal) limited to a local area.

One-segment broadcasting (one-segment partial reception service for cellular phones and mobile terminals) has been carried out as terrestrial digital television broadcasting for portable terminals such as cellular phones, and portable devices capable of receiving this one-segment broadcasting are also spreading. .
In general one-segment broadcasting, the same content as terrestrial digital broadcasting assigned to one segment is transmitted, and the user receives this with a mobile terminal and plays back and enjoys video and audio data.

  Recently, it has been attempted to distribute content that can be viewed only in a narrow area (local area) not only to contents broadcast from a broadcasting station over a wide area, but also to one-seg compatible devices. As a result, the possibility of a content distribution service that has never existed such as a content distribution service rich in locality is greatly expected.

  However, UHF (ultra-high frequency), which is a radio wave band used in terrestrial digital broadcasting and one-segment broadcasting, is suitable for digital broadcasting and broadcasting for mobile communication, but it does not affect the human body or interfere with other radio waves. Therefore, the transmission output is strictly regulated by the Radio Law. For example, even for a local area, we want to cover a range of several meters in radius, but the Radio Law stipulates that content will be transmitted to a one-segment receiving terminal with radio field intensity covering a transmission area with a radius of several meters (for example, 5 meters). A license is required. For this reason, no one can immediately create and transmit one-seg content, which hinders the spread of good content distribution services.

Here, Patent Document 1 describes a re-transmission device that re-transmits digital terrestrial broadcasting including one-seg broadcasting when providing one-seg broadcasting even in a radio wave shielding space or a weak electric field space.
In this retransmission apparatus, it has been proposed to convert received terrestrial digital broadcasts into lower frequency radio waves (eg, VHF band) and retransmit. Radio frequency regulations are relaxed at frequencies in this region, and even if there is no license under the radio law, it is allowed to transmit radio waves with considerable electric field strength, so the reach of retransmitted radio waves can be extended . If this re-transmission device is used, content distribution for portable terminals in a local area may be possible.

JP 2007-318404 A

In the configuration of Patent Document 1, radio waves are transmitted in a frequency band different from the one-segment broadcasting. Certainly, it is possible to cover a large area even without a license under the radio law by transmitting with a certain intensity using a lower frequency band. However, since broadcasting is performed in a frequency band that cannot be received by a commercially available mobile terminal, a user using a commercially available mobile terminal cannot view this content distribution and cannot solve the problem at all.
On the other hand, when the frequency band for one seg is used, since the transmission intensity is severely limited, only weak radio waves can be used, and there remains a problem that it does not cover a meaningful area for content transmission.

  An object of the present invention is to provide a content data transmission system covering a local area having a sufficient area and a transmission apparatus suitable for this system.

  The content data transmission system of the present invention is a content data transmission system for transmitting content data received and viewable by a portable mobile terminal to a service area of a predetermined area, and is arranged at a plurality of locations in the service area. A plurality of transmission devices, wherein each of the plurality of transmission devices is arranged in a state in which each individual radio wave transmission area overlaps a radio wave transmission area of at least one other transmission device, and each of the transmission devices has the service area A data reading unit for sequentially reading data of content distributed to the portable mobile terminal, a transmission processing unit for performing transmission processing for converting the content data read by the data reading unit into a radio signal, and the transmission processing unit An antenna for transmitting the radio wave signal processed by the transmission processing unit, wherein the transmission processing unit Characterized in that it comprises a transmission synchronizing section for synchronizing the transmission timing of the content data in all of the transmitter in Bisueria.

In such a configuration, a plurality of transmission devices are arranged in the service area. Each transmission device reads the content data by the data reading unit, converts the content data by the transmission processing unit, and transmits the radio wave. At this time, all the transmission apparatuses in the service area synchronize the timing of transmitting the content data by the synchronization processing of the transmission synchronization processing unit, and transmit the data at the same timing.
In this state, the user receives radio waves using the mobile terminal. Then, the content is viewed on the mobile terminal. And when a user moves with a portable terminal, the portable terminal will move from the cover area of one transmission device to the cover area of another transmission device. Even if a radio wave is transmitted from the mobile phone, the content data synchronized in the entire area is transmitted, so that the data received by the mobile terminal maintains continuity. As a result, the mobile terminal does not recognize that the radio wave sources are different, continuously receives the same content data, and continuously provides the video and audio to the user. That is, according to such a configuration, the user can view the content while freely moving in the service area.

  In the present invention, each of the transmission devices includes a time counter unit that counts an internal time, and the transmission synchronization processing unit has the same transmission start time set in all the transmission devices, and the transmission synchronization processing unit Preferably, when the time counted by the time counter unit reaches the transmission start time, the data reading unit starts reading content data and transmits the content data from the antenna.

  According to such a configuration, content transmission is started from the same transmission start time by all the transmission devices, and thereafter, the content is transmitted from all the transmission devices at the same timing. As a result, all the content data transmitted in the area are synchronized.

  In the present invention, remote control means capable of transmitting a control signal to all transmission devices arranged in the service area by wired or wireless communication is provided, and the remote control means is provided inside the remote control means. The time information being counted and the command for starting the transmission of content data are transmitted on the control signal, and the time counter unit of the transmitting device synchronizes with the time information of the control signal. Preferably, the count value is corrected, and the transmission synchronization processing unit sets the transmission start time of the content data based on the transmission start time commanded by the control signal.

In such a configuration, time information is sent from the remote control means to all the transmission devices, and the time information counted by the time counter of each transmission device is synchronized based on this time information. Then, the content transmission is started from the same transmission start time in all the transmission devices.
Since the internal time is synchronized in all the transmission devices by the control signal from the remote operation means and the content transmission is started from the same start time, all the content data transmitted in the area are synchronized.
Also, since the internal time of each transmitter is synchronized with the remote control means and the same transmission start time is set for all transmitters, transmission can be started even if communication with all transmitters cannot be established at the same time. If the time is set to a sufficiently long time, it is possible to sequentially communicate with the individual transmission devices and the remote control means. In an area with a certain extent, it may be difficult to secure communication with all the transmitting devices at the same time. However, according to the configuration of the present invention, it is possible to communicate with each transmitting device and the remote control means in order. Good.

  In the present invention, the time counter unit of the transmitter includes an RTC crystal resonator that generates an oscillation pulse for time counting with a period of 125 μsec or less, and a sub-second pulse for loop counting the oscillation pulse within one second. A counter, a second pulse generator for generating a second pulse that rises every second based on the count value of the sub-second pulse counter, a current time counter that counts the current time based on the second pulse, the current time counter, and A counter correction unit that corrects the count value of the sub-second pulse counter, and the count value of the current time counter and the sub-second pulse counter is synchronized with time information from the remote control means by the counter correction unit. On the other hand, it is preferable that the RTC crystal unit continue to oscillate without being reset.

In such a configuration, the counter correction unit corrects the count values of the current time counter and the sub-second pulse counter and synchronizes with the internal time of the remote control means.
On the other hand, since the oscillation of the crystal resonator for RTC is not reset, there is a possibility that the oscillation timings of the respective vibrators are different between the remote control means and the transmission device, and furthermore, the vibrators ( There is a possibility that the oscillation timings of the crystal resonator for RTC are all different.
In this case, the oscillation deviation of the vibrator (RTC crystal vibrator) also shifts the content data transmission timing.
In this regard, in the transmission of content data for portable mobile terminals, an allowable synchronization deviation is set according to the standard because it is not affected by reflected waves from obstacles. There may be a gap.
In the present invention, the period of the vibrator (RTC crystal vibrator) is made sufficiently short so that the synchronization deviation is allowed within one period of the vibrator.
Even when there is such a deviation, continuity can be maintained when viewing content on a portable terminal, and since the vibrator is not reset, time synchronization can be easily performed.

In the present invention, it is preferable that the remote control means transmits a control signal by wireless communication to all the transmission devices arranged in the service area.
For example, wireless communication may be established by infrared communication.
Since it is only necessary to establish communication with a plurality of transmission devices arranged in a limited service area, it is possible to remotely control all transmission devices in the area even with simple infrared communication.
In addition, a certain laser diffusion angle is set even in known infrared transmission means, and if this is used, it is suitable for remote control with respect to a transmission apparatus arranged with a spread in a limited area.

In the present invention, it is preferable that all transmission devices are connected to a network line, and the remote control means is a host computer connected to the network line.
The network line may be an Internet line or a locally built LAN line.

  In the present invention, the transmission device includes content data storage means for storing content data to be distributed to the portable mobile terminal in the service area, and the content data storage means can be inserted into and removed from each transmission device. A storage medium is preferred.

  In the present invention, it is preferable that all transmission devices are connected to a network line, and content data is supplied to the transmission device via the network line.

  In the present invention, the content data storage means preferably stores content data that has been subjected to compression and encoding processing in accordance with a standard for the portable mobile terminal.

  In the present invention, it is preferable that the content data supplied to the transmission device via the network line is data that has been subjected to compression and encoding processing in accordance with the standard for the portable mobile terminal.

By giving the data processed in advance to the transmission device in this way, the transmission device only needs to read and transmit the data.
Therefore, the configuration of the transmission device can be simplified.

In the present invention, the transmission processing unit includes an output adjustment unit that adjusts the transmission output to a weak electric field strength that does not require a license, and the transmission output has an electric field strength of 35 μV / m when separated from each transmission device by 3 m. The following is preferable.
With such a transmission output, no license under the Radio Law is required.
And even if the transmission output from each transmission apparatus is small, according to this invention, the transmission of the content data synchronized in the wide area can be performed.

  The transmission device of the present invention is a transmission device that constitutes a content data transmission system for transmitting content data received and viewable by a portable mobile terminal to a service area of a predetermined area, and the mobile device within the service area Processed by a data reading unit that sequentially reads data of content distributed to a mobile terminal, a transmission processing unit that performs transmission processing for converting content data read by the data reading unit into a radio signal, and the transmission processing unit And an antenna for transmitting a radio wave signal, wherein the transmission processing unit includes a transmission synchronization processing unit that synchronizes the transmission timing of the content data in all the transmission devices in the service area.

  The present invention further includes content data storage means for storing data of content distributed to the portable mobile terminal in the service area, and the content data storage means is a storage medium that can be inserted into and removed from the transmission device. Preferably, the content data storage means stores content data that has been compressed and encoded according to the standard for the portable mobile terminal.

  According to such a configuration, it is possible to obtain a transmission device suitable for constructing the content data transmission system.

Embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
A first embodiment of the content data transmission system of the present invention will be described.
FIG. 1 is a diagram showing an overall configuration of a content data transmission system 100 according to the first embodiment.
In the first embodiment, the content data transmission system 100 includes a plurality of transmission devices 200 arranged at a plurality of locations in a service area, and a remote controller (remote operation means) 910 for remotely controlling these transmission devices 200. I have.

A plurality of transmission apparatuses 200 are arranged at predetermined intervals in the service area.
The service area here is an area having a radius of several meters when it is narrow and a radius of several tens of meters when it is wide. For example, a service area or one floor of an office building can be cited as an example.
Each transmitting apparatus 200 has the same configuration, and the configuration will be described with reference to FIG.

FIG. 2 is a block diagram illustrating the configuration of the transmission device 200.
The transmission device 200 includes a memory card (content data storage unit) 210 on which content data is recorded, a time counter unit 220 that counts time, a reception unit 230 that receives a control signal from the remote controller 910, and content data A transmission unit 240 that performs transmission.
Furthermore, the transmission apparatus 200 includes a system clock 280 that generates a clock that serves as a reference for determining the operating frequency.

The memory card 210 can be inserted into and removed from the transmission device 200, and records content data to be distributed to the service area.
The content itself of the content data is not particularly limited, but examples include a case where entertainment content and various useful information are incorporated by combining video, audio, and data broadcasting information.
A plurality of such contents may be prepared and recorded separately for each program.
The content data is encoded according to a standard corresponding to one segment (One Seg) of ISDB-T so that it can be received and played by a mobile terminal 990 compatible with One Seg, and processing such as compression and encoding has been completed. It is recorded on the memory card 210 in a state.

  The time counter unit 220 includes an RTC crystal resonator 221 that generates an oscillation pulse for time counting, a sub-second pulse counter 222 that counts an oscillation pulse within one second, and a second pulse that generates a second pulse every second. A generation unit 223, a current time counter 224 that counts the current time, and a counter correction unit 225 that corrects the count values of the current time counter 224 and the sub-second pulse counter 222 are provided.

The RTC crystal resonator 221 oscillates at, for example, 32.768 KHz (period 30.5 μsec), is a temperature compensation type, and has a room temperature accuracy of ± 2 ppm or less. Shows this oscillation pulse in FIG. 3, reference numeral of P _2.

The sub-second pulse counter 222 counts the oscillation pulses of the RTC crystal resonator 221. That is, the oscillation pulse is loop-counted from 0 to 32767 (= 2 ¹⁵ −1).
The state of counting oscillation pulses of less than a _second is shown superimposed on P2 in FIG.

The second pulse generation unit 223 sets the second pulse to High when the count value of the sub-second pulse counter 222 becomes 0, and generates a second pulse that rises every second.
The second pulse shown in FIG. 3 at reference numeral P _3.
The current time counter 224 includes, for example, a year / month / day counter, an hour / minute counter, and a second counter. Then, the count value of the second counter is updated by the second pulse from the second pulse generator 223, and the hour / minute counter and the year / month / day counter are also updated accordingly.

The counter correction unit 225 corrects the count values of the current time counter 224 and the sub-second pulse counter 222 based on a control signal from the remote controller 910.
Since there are a plurality of transmission devices 200 in the service area, it is necessary to synchronize the internal time of all the transmission devices 200 within an allowable range, and the internal time (current time counter 224) is based on a control signal from the remote controller 910. And the sub-second pulse counter 222) is modified.
A specific operation in which the counter correction unit 225 corrects the count values of the current time counter 224 and the sub-second pulse counter 222 will be described later.

  The receiving unit 230 includes a light receiving unit 231 that receives a control signal from the remote controller 910 and a reception processing unit 232 that receives and processes the control signal received by the light receiving unit 231.

The receiving unit 230 establishes infrared communication with the remote controller 910.
The light receiving unit 231 receives the infrared laser signal from the remote controller 910, and outputs the photoelectrically converted electric signal to the reception processing unit 232.
The reception processing unit 232 includes a decoder 233 that decodes a control signal from the remote controller 910 received via the light receiving unit 231, and a signal processing unit 234 that extracts an instruction from the decoded signal.

  The transmission unit includes a data reading unit 250 that sequentially reads content data from the memory card 210, a transmission processing unit 260 that performs synchronization processing, modulation processing, and output adjustment processing on the data read by the data reading unit 250, and transmission processing unit 260. And an antenna 270 for transmitting the transmission data.

The data reading unit 250 sequentially reads content data from the memory card 210 and sequentially sends a predetermined amount of data to the transmission processing unit 260 while temporarily buffering the data.
At this time, for example, if a predetermined program program of content is selected by the remote controller 910, the selected content data is sequentially read out.
The operation timing of reading and sending data follows the clock of the system clock 280.

  The transmission processing unit 260 includes a transmission synchronization processing unit 261 that synchronizes the transmission timing of content data with other transmission apparatuses 200, a modulation processing unit 262 that performs modulation for placing content data on a carrier wave for one seg, and a transmission output license. And an output adjustment unit 263 that adjusts to a weak electric field intensity that does not require the control.

The transmission synchronization processing unit 261 synchronizes the transmission start time of the content data with the other transmission devices 200 based on the control signal from the remote controller 910.
At this time, the transmission synchronization processing unit 261 determines the data transmission start time by the control signal from the remote controller 910 and confirms the current time by referring to the count values of the current time counter 224 and the sub-second pulse counter 222. Then, when the count values of the current time counter 224 and the sub-second pulse counter 222 coincide with the transmission start time, the transmission process is started, and the data temporarily buffered in the data reading unit 250 is sequentially sent to the modulation process.

The modulation processing unit 262 modulates content data for one segment using a frequency of 470 MHz to 710 MHz.
The output adjustment unit 263 adjusts the transmission output from the antenna 270.
The transmission output is a weak radio wave that does not require a license according to the Radio Law even when data is transmitted from this transmission device, and the electric field intensity at a distance of 3 m is set to 35 μV / m or less, for example.

  Here, the transmission processing unit 260 and the data reading unit 250 constitute a transmission control unit that performs transmission control of content data.

  The system clock 280 has, for example, a crystal resonator 281 of 32.5079 MHz (period 30.76 nsec), has an accuracy of ± 10 ppm or less, and oscillates with a period sufficiently shorter than the amount of deviation in transmission timing allowed between transmission apparatuses. To do. Based on the clock of the system clock 280, the operation cycle of the data reading unit 250, the transmission processing unit 260, and the reception processing unit 232 is defined.

The remote controller 910 can perform infrared communication with the transmission device 200 and sends a user instruction to each transmission device 200 by infrared communication.
User operations using the remote controller 910 include a content data transmission start command, a content selection command, a data skip command, and the like.
Although the configuration of the remote controller 910 is not described in detail, the remote controller 910 includes various buttons for operation by the user, an operation detection unit that detects button operations, and an infrared transmission unit that encodes commands by button operations and transmits data. It has. Furthermore, the remote controller 910 includes time counting means having the same configuration as the time counter unit 220 of the transmission apparatus 200, and includes an RTC crystal resonator, a sub-second pulse counter, a second pulse generator, and a current time counter.
The RTC crystal resonator included in the time count means of the remote controller 910 is the same as the RTC crystal resonator 221 included in the transmission device 200. For example, it oscillates at 32.768 kHz, is a temperature compensated type, and the room temperature accuracy is ± 2 ppm or less. It is.
The control circuit of the remote controller 910 has a system clock that defines the operating frequency, and this system clock is the same as that built in the transmission apparatus 200. That is, the system clock has, for example, a crystal resonator of 32.5079 MHz (period 30.76 nsec), the accuracy is ± 10 ppm or less, and oscillates with a period sufficiently shorter than the amount of deviation in transmission timing allowed between transmission apparatuses. .

When the remote controller 910 detects an instruction from a user, the remote controller 910 generates a control signal by adding the count time information from the time counter unit 220 to the instruction from the user, and transmits the control signal to each transmission device 200.
The infrared transmitter of the remote controller 910 transmits laser light having a predetermined intensity with a predetermined angular width.
In order to establish communication all at once from the remote controller 910 to the transmitter 200 in the area, it is preferable that the diffusion angle of the laser light has a spread of, for example, about 60 ° to 120 °.
Here, the diffusion angle refers to a full-width (half-value full-width) position representing a half-value of the center luminance.

The operation and use of the first embodiment having such a configuration will be described.
In using the content data transmission system 100, first, a preparation process is required.
The preparation process is shown in the flowchart of FIG.
In the preparation step, first, content data is produced (content production step ST100), and encoded according to a standard corresponding to one segment (one segment) of ISDB-T (encoding step ST110). Then, the content data thus encoded is recorded in the memory card 210 (data recording step ST120).
The same number of memory cards 210 are required as the number of transmitting apparatuses 200 to be arranged.
The memory card 210 storing the content data in this way is set in a predetermined slot of the transmission device 200 (memory setting step ST130).

After the memory cards 210 are set in all the transmitting devices 200, each transmitting device 200 is disposed at a predetermined position in the service area (transmitting device disposing step ST140).
Here, when arranging in the area, radio waves transmitted from the transmission apparatus 200 are overlapped between adjacent apparatuses.
For example, when the transmission intensity from each transmission device 200 is set to 35 μV / m at a distance of 3 m, the range that can be covered by one transmission device 200 is a radius of about 3 m, so that the transmission device 200 has an interval of less than 3 m within the service area. To be placed in.
In addition, when arranging the transmission apparatus 200 in the service area, as shown in FIG. 1, the transmission areas overlap with all the transmission apparatuses 200 that are adjacent to each other as viewed from one transmission apparatus. Of course, the transmission areas may not overlap even if they are adjacent to each other. In some cases, the entire space may not be a service area capable of receiving radio waves due to physical space restrictions and cost reasons.
In other words, it is not always necessary that the transmission area overlaps with all the transmission devices that are adjacent to each other. For example, the transmission area is arranged so that the transmission area overlaps with at least the nearest adjacent transmission device. May be.
With this arrangement, each transmitter 200 is turned on (power-on process ST150).
This completes the preparation process.

Here, if the same content data is transmitted from a plurality of transmission devices 200, the content data can be received and viewed in a wide area. Then, content data is transmitted from each transmission device 200 at a unique timing different from other transmission devices.
Even if the content data is the same, if the transmission timing is different for each transmission apparatus 200, for example, if it is a moving image content, different frame data is transmitted.
Here, FIG. 5 is a diagram illustrating a state in which adjacent transmission apparatuses 200 are transmitting content data at different transmission timings.
In such a state, there is no particular problem as long as the mobile terminal 990 receives radio waves while staying within the area covered by one transmission device 200.

However, a problem occurs when a user with the portable terminal 990 leaves the cover area of one transmitter 200 and enters the cover area of the adjacent transmitter 200.
In this case, when viewed from the portable terminal 990, the continuity of the data received so far is interrupted. Then, the mobile terminal 990 stops receiving radio waves that have been received so far, searches for radio waves that can be received again, and starts reception processing of radio waves having a reception intensity equal to or higher than a predetermined threshold.
Such a re-search process takes a considerable time (for example, several seconds).
That is, even if all the transmission devices 200 transmit the same content data, there is a problem that the mobile terminal 990 moving within the service area cannot continuously view the content if the transmission timing is shifted.

Therefore, it is necessary to synchronize the transmission timing of all the transmission apparatuses 200 using the remote controller (remote operation means) 910 and transmit the same content data.
Specifically, operations and processing for synchronizing the transmission apparatus 200 will be described in order.
In order to synchronize the transmission devices 200, it is necessary to match the counter values of the internal times of all the transmission devices 200 and the remote controllers 910.
FIG. 6 is a diagram illustrating the relationship between the count timings of the times when the remote controller 910 and the two transmission apparatuses (transmission apparatus A and transmission apparatus B) respectively count internally before the synchronization process is performed. .
As shown in FIG. 6, in the remote controller 910 and each transmission device (transmission devices A and B), the oscillation timings of the respective RTC crystal resonators (221) are out of sync and are not synchronized.
Further, the remote controller 910 and each transmission device (transmission devices A and B) have different count timings of the sub-second pulse counter (222), and the count value of the sub-second pulse counter (222) becomes zero. It's off. The remote controller 910 and the transmission devices (transmission devices A and B) also have different count values of the current time counter (224) in the remote controller 910 and the transmission device A has the internal time T _C that the remote controller 910 has. The internal time T _A and the internal time T _B possessed by the transmitter _B are all different.

7 and 8 are flowcharts showing operations from when the user operates the remote controller 910 to when content data is transmitted by the transmission apparatus 200. FIG.
First, when the user operates a button on the remote controller 910, the button operation is detected by the remote controller 910 (button operation detection step ST200).
The command by the button operation is processed in the remote controller and encoded into a control signal (command processing step ST210).
Here, examples of the control signal sent from the remote controller 910 to the transmission device 200 include content selection and transmission start time Ts.
The transmission start time Ts may be instructed by the user as a reserved time for starting transmission, such as “start transmission from 10:00 AM of 1 day”. Alternatively, when a content selection command is sent, a default setting may be made so that the transmission start time Ts is set 2 seconds after the content selection command. Further, the remote controller 910 generates a control signal by combining the count time information by the internal time counter unit with the command by the button operation.
A control signal from the remote controller is transmitted by infrared rays (infrared transmission step ST220).

  The control signals transmitted from the remote controller 910 are received all at once by all the transmitting devices 200 arranged in the area (infrared receiving step ST300).

The light receiving unit 231 of each transmission device 200 receives infrared rays.
Then, the photoelectrically converted control signal is sent to the decoder 233, and the control signal is decoded (decode processing step ST310).
Then, the control signal is processed by the signal processor 234 and various commands are extracted (signal processing step ST320).
Among the extracted commands, information on the transmission start time Ts is sent to the transmission synchronization processing unit 261, and the transmission start time Ts is set (start time setting step ST330).
The content selection command is sent to the data reading unit 250, and the content to be read from the memory card 210 is selected (read content selection step ST340).

Then, the time information of the remote controller 910 extracted from the control signal is sent to the counter correction unit 225, where the time of the time counter unit 220 is corrected (counter correction step ST350).
At this time, since the processing time D _A in the processing time D _C a transmitter inside the remote controller is a fixed and known, the time information contained in the control signal (T _C and sec pulse counter value) Based on the value obtained by adding the processing time D _C + D _A , the counter correction unit 225 rewrites the internal time (the current time counter 224 and the second-second pulse counter 222).
FIG. 9 shows how the count value of the subsecond pulse counter 222 is corrected and the pulse timing of the second pulse generator 223 is corrected accordingly.
In this way, the time counter unit 220 of the transmission device 200 is corrected in synchronization with the internal time information of the remote controller 910.

However, since the oscillation of the RTC crystal resonator 221 is not reset, there is a possibility that a deviation within one cycle of the RTC crystal resonator 221 remains (see FIG. 9).
In this regard, in the ISDB-T specification, a deviation within 125 μsec is allowed, so this is not a problem.

By such an operation, in addition to the transmission device A, the time counter units 220 of all the transmission devices 200 arranged in the area are similarly synchronized.
When the synchronization of the time counter unit 220 is completed in this way, the transmission synchronization processing unit 261 determines whether or not the instructed transmission start time Ts has been reached by referring to the time information of the time counter unit 220 (ST360).
When the transmission start time Ts is reached (ST360: YES), the data reading unit 250 reads the content data (data reading step ST370).
The content data read by the data reading unit 250 is modulated by the modulation processing unit 262 to a predetermined frequency (470 MHz to 710 MHz for one seg) (modulation step ST380), and further output adjustment is performed by the output adjustment unit 263 (output adjustment) Step ST390).
The adjustment output is a weak radio wave intensity such that the electric field intensity at a distance of 3 m is 35 μV / m or less.
The content data processed in this way is transmitted from the antenna 270 (content transmission step ST400).
FIG. 10 shows how each transmission device starts transmitting content data with a predetermined synchronization accuracy.

Then, the same content data is transmitted at the same timing from all the transmission devices 200 in the area.
Therefore, content can be viewed by receiving radio waves with the one-seg portable terminal 990 in this area, and even when moving from the cover area of one transmitter 200 to the cover area of another transmitter 200 The continuity of data to be processed is not interrupted. Then, even if the transmission source is different, the portable terminal 990 continuously receives the same content data and continuously provides the video and audio to the user.

As mentioned above, according to 1st Embodiment provided with such a structure, there can exist the following effects.
(1) All transmission apparatuses 200 in the service area synchronize the timing of transmitting content data by the synchronization processing of the transmission synchronization processing unit 261, and transmit data at the same timing. Therefore, even when the user moves with the mobile terminal 990, the data received by the mobile terminal 990 maintains continuity. As a result, the mobile terminal 990 does not recognize that the radio wave source is different, and the same content The data is continuously received and the video and audio are continuously provided to the user. That is, the user can view the content while freely moving in the service area.

(2) The transmission synchronization processing unit 261 causes the data reading unit 250 to start reading content data when the time counted by the time counter unit 220 reaches the transmission start time, and sends the content data from the antenna 270. Since transmission is performed, content transmission is started from the same transmission start time in all the transmission devices 200, and thereafter, content is transmitted from all the transmission devices 200 at the same timing. As a result, all the content data transmitted in the area can be synchronized.

(3) Since the content transmission is started from the same start time after the internal time is synchronized in all the transmission devices 200 by the control signal from the remote controller 910, all the content data transmitted in the area can be synchronized. it can.
In addition, since the same transmission start time is set for all the transmission devices 200 after the internal time of each transmission device 200 is synchronized with the remote controller, communication with all the transmission devices 200 cannot be established at the same time. However, if the transmission start time is set sufficiently earlier, it is possible to communicate with the individual transmission devices 200 and the remote controller in order.
In an area with a certain extent, it may be difficult to ensure simultaneous communication with all the transmission devices 200. However, according to the configuration of this embodiment, the individual transmission devices 200 and the remote controllers 910 are sequentially connected. You may make it communicate.

(4) Although the counter correction unit 225 corrects the count values of the current time counter 224 and the sub-second pulse counter 222, the RTC crystal resonator 221 continues to oscillate without being reset.
In transmission of content data for portable mobile terminals, an allowable synchronization shift is set in the standard because it is not affected by a reflected wave by an obstacle, and there is a synchronization shift within such an allowable range. May be. Therefore, by adopting a configuration in which the period of the vibrator (RTC crystal vibrator) is sufficiently shortened so that the synchronization deviation is allowed within one period of the vibrator. Since the vibrator is not reset in this way, time synchronization can be easily performed.

(5) Since the content data is recorded on the memory card 210 in a state where the compression and encoding processing is completed according to the standard for mobile terminals (one-seg compatible standard), the transmission device 200 reads the data. Just send it.
Therefore, the transmission apparatus 200 does not need a compression or encoding function, and can quickly execute from data reading to transmission.

(6) The output adjustment unit 263 adjusts the output so that the electric field intensity when separated from the transmission device 200 by 3 m is 35 μV / m or less. Since such a weak radio wave is transmitted, it is not necessary to obtain a license specified by the Radio Law. And even if the transmission output from each transmission apparatus 200 is small, a plurality of synchronized transmission apparatuses are arranged, so that synchronized content data can be transmitted in a wide area.

Next, a second embodiment of the present invention will be described.
The basic configuration of the second embodiment is the same as that of the first embodiment. However, in the second embodiment, service areas exist at two remote locations and content data is transmitted via the Internet line. It is characterized in that it is provided to the device.
FIG. 11 is a diagram illustrating a configuration of the second embodiment.
In FIG. 11, there are a plurality of (for example, two) areas where content data is distributed, and a transmission apparatus 300 is arranged at a predetermined interval in each area.
A router 400 is installed for each area, and the transmission device 300 in each area is connected to the router 400.
Each router 400 is connected to the Internet line 410.
A host computer (remote operation means) 420 is connected to the Internet line 410.

The host computer 420 stores content data for mobile terminals that are compatible with 1Seg.
The host computer 420 has a content distribution schedule.
The host computer 420 distributes the content data to each transmission device 300 via the Internet line 410 according to this distribution schedule.
When content data is distributed from the host computer 420, start time information for matching the transmission timing is also distributed.

FIG. 12 is a diagram illustrating a configuration of the transmission device 300 according to the second embodiment.
The configuration of the transmission apparatus 300 in the second embodiment is basically the same as that of the transmission apparatus 200 in the first embodiment. However, the host computer 420 receives content data and time information for synchronization processing via an interface (I / F). It is characterized in that it is obtained from
In FIG. 12, the distribution of content data is received from the host computer 420 via the I / F (interface) 290, and the received content data is stored in the temporary content buffer 251.
A program schedule is distributed from the host computer 420 together with the content data, and the received program schedule is sent to the transmission synchronization processing unit 261.
Further, time information by, for example, NTP (network time protocol) is sent from the host computer 420, and based on this NTP time information, the count value of the time counter unit 220 (the count value of the pulse counter 222 and the count of the current time counter 224) Value) is modified.

The operation and use of the second embodiment having such a configuration will be described.
The content data and the program distribution schedule are stored in the host computer 420, and the host computer 420 is connected to the Internet line 410.
A predetermined number of transmitting apparatuses 300 are arranged in each area, connected to the Internet line 410 via the router 400, and a connection between each transmitting apparatus 300 and the host computer 420 is established.
Then, the content data and the program schedule are distributed from the host computer 420 in time for the program start time.

All the transmission devices 300 simultaneously receive data transmission from the host computer 420 through the Internet line 410.
However, when a difference in communication speed occurs, a slight deviation occurs.
The transmission device 300 receives content data and a program schedule, and acquires NTP (Network Time Protocol) time information.
The content data is temporarily stored in the content buffer 251 in the order of reception and is in a standby state until transmission. The program schedule is sent to the transmission synchronization processing unit 261, and the transmission synchronization processing unit 261 reads and sets the transmission start time from the program schedule.
The NTP time information is sent to the time counter unit 220, and the counter correction unit 225 corrects the count values of the sub-second pulse counter 222 and the current time counter 224.
For this correction method, the method described in the first embodiment can be similarly applied.

The transmission synchronization processing unit 261 compares the set transmission start time with the count value of the time counter unit 220, and starts transmission of content data when they match.
That is, the data reading unit 250 sequentially reads the contents temporarily stored in the content buffer 251 and sends them to the transmission processing unit 260.
In the transmission processing unit 260, content data is transmitted from the antenna 270 by performing modulation processing by the modulation processing unit 262 and output adjustment by the output adjustment unit 263.
The transmitted content data is received by the portable terminal 990 and viewed.

According to 2nd Embodiment provided with such a structure, in addition to the effect of the said embodiment, there can exist the following effect.
That is, it is possible to transmit content data synchronized in a service area of a predetermined area. Since communication using the Internet line 410 is used, even if there are a plurality of service areas, the transmission apparatus 300 can be synchronized in all service areas to provide a content data transmission service. .

(Modification)
In configuring the content data transmission system, the transmission apparatus 500 is configured such that the content data is recorded on the memory card 210 and the transmission start time and current time information are provided via the Internet line 410 as shown in FIG. It is good. Even in such a configuration, the same operational effects as those of the above-described embodiment can be obtained.

Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention described above.
In the above embodiment, the case where the time counter is always corrected when receiving the control signal from the remote controller has been described. However, the time counter is not necessarily rewritten, for example, the control signal from the remote controller is received. In this case, the time difference may be compared between the remote controller and the transmission device, and the time may be corrected only when the allowable range is exceeded.
In the second embodiment, the Internet line is used, but this may be a locally built LAN line.
The oscillation frequency of the crystal resonator for RTC is not limited to the above embodiment, and one period may be within 125 μsec.
In the first embodiment, the remote controller and the transmission device perform infrared communication, but the wireless communication method is not particularly limited.
The transmission output in the above embodiment is merely an example, and it is needless to say that it can be appropriately selected and adjusted with an output that does not require a license under the Radio Law.

The figure which shows the whole structure of the content data transmission system which concerns on 1st Embodiment. The block diagram showing the structure of a transmitter. The figure for demonstrating the time count in a time counter part The figure which shows the procedure of the preparation process in using the content data transmission system which concerns on 1st Embodiment. The figure showing a mode that the adjacent transmission apparatus is transmitting content data with a different transmission timing. The figure which shows the relationship of the count timing of the time which a remote controller and two transmitters are each counting in the state before performing a synchronization process. The flowchart which shows operation | movement after a user operates a remote controller until content data is transmitted with a transmitter. The flowchart which shows operation | movement after a user operates a remote controller until content data is transmitted with a transmitter. The figure which shows a mode that the pulse timing of a second pulse generation part is corrected according to correcting the count value of a pulse counter below a second. The figure which shows a mode that each transmission apparatus starts transmission of content data with predetermined | prescribed synchronization precision. The figure which shows the structure of 2nd Embodiment. The figure which shows the structure of the transmitter in 2nd Embodiment. The figure which shows the structure of the transmitter in a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Content data transmission system, 200 ... Transmission apparatus, 210 ... Memory card, 220 ... Time counter part, 221 ... Crystal oscillator for RTC, 222 ... Sub-second pulse counter, 223 ... Second pulse generation part, 224 ... Current time counter 225 ... Counter correction unit 230 ... Reception unit 231 ... Light reception unit 232 ... Reception processing unit 233 ... Decoder 234 ... Signal processing unit 240 ... Transmission unit 250 ... Data reading unit 251 ... Content buffer 260 ... Transmission processing unit, 261 ... Transmission synchronization processing unit, 262 ... Modulation processing unit, 263 ... Output adjustment unit, 270 ... Antenna, 280 ... System clock, 281 ... Crystal oscillator, 300 ... Transmission device, 400 ... Router, 410 ... Internet line, 420 ... host computer, 500 ... transmission device, 910 ... remote control Controller, 990 ... mobile terminal.

Claims (13)

A content data transmission system for transmitting content data received and viewable by a portable mobile terminal to a service area of a predetermined area,
Comprising a plurality of transmitters arranged at a plurality of locations in the service area;
The plurality of transmission devices are arranged in a state where each individual radio wave transmission area overlaps a radio wave transmission area of at least one other transmission device,
Each of the transmission devices
A data reading unit for sequentially reading data of contents distributed to the portable mobile terminal in the service area;
A transmission processing unit for performing transmission processing for converting content data read by the data reading unit into a radio wave signal;
An antenna for transmitting the radio wave signal processed by the transmission processing unit,
The transmission processing unit includes a transmission synchronization processing unit that synchronizes the transmission timing of the content data among all the transmission devices in the service area. The content data transmission system according to claim 1,
Each of the transmission devices includes a time counter unit that counts the internal time,
In the transmission synchronization processing unit, the same transmission start time is set in all the transmission devices,
The transmission synchronization processing unit causes the data reading unit to start reading content data and transmit the content data from the antenna when the time counted by the time counter unit reaches the transmission start time. A content data transmission system. The content data transmission system according to claim 2,
Remote control means capable of transmitting a control signal by wired or wireless communication to all transmission devices arranged in the service area;
The remote control means transmits the time information counted inside the remote control means and a command of the transmission start time of the content data on the control signal,
The time counter unit of the transmission device corrects the count value of the internal time in synchronization with the time information of the control signal,
The transmission synchronization processing unit sets a transmission start time of content data based on the transmission start time commanded by the control signal. In the content data transmission system according to claim 3,
The time counter unit of the transmission device is
An RTC crystal resonator that generates a time-counting oscillation pulse having a period of 125 μsec or less;
A sub-second pulse counter that loop-counts the oscillation pulse within one second, and
A second pulse generator for generating a second pulse that rises every second based on the count value of the pulse counter below the second,
A current time counter that counts the current time based on the second pulse;
A counter correction unit that corrects a count value of the current time counter and the sub-second pulse counter,
While the count values of the current time counter and the sub-second pulse counter are corrected by the counter correction unit in synchronization with the time information from the remote control means, the RTC crystal resonator continues to oscillate without being reset. A content data transmission system characterized by: In the content data transmission system according to claim 3 or 4,
The content data transmission system, wherein the remote control means transmits a control signal by wireless communication to all transmission devices arranged in the service area. In the content data transmission system according to claim 3 or 4,
All transmitters are connected to network lines
The content data transmission system, wherein the remote control means is a host computer connected to the network line. In the content data transmission system according to any one of claims 1 to 6,
The transmission device includes content data storage means for storing data of content distributed to the portable mobile terminal in the service area,
The content data storage system is a storage medium that can be inserted into and removed from each transmission device. The content data transmission system according to any one of claims 1 to 5,
All transmitters are connected to network lines
Content data transmission system, wherein content data is supplied to the transmission device via the network line. The content data transmission system according to claim 7,
The content data storage system stores content data that has been compressed and encoded according to a standard for the portable mobile terminal. The content data transmission system according to claim 9,
The content data transmission system, wherein the content data supplied to the transmission device via the network line is data that has been compressed and encoded according to a standard for the portable mobile terminal. The content data transmission system according to any one of claims 1 to 10,
The transmission processing unit includes an output adjustment unit that adjusts the transmission output to a weak electric field strength that does not require a license,
The content data transmission system, wherein the transmission output has an electric field strength of 35 μV / m or less when separated from each transmission device by 3 m. A transmission device constituting a content data transmission system for transmitting content data received and viewable by a portable mobile terminal to a service area of a predetermined area,
A data reading unit for sequentially reading data of contents distributed to the portable mobile terminal in the service area;
A transmission processing unit for performing transmission processing for converting content data read by the data reading unit into a radio wave signal;
An antenna for transmitting the radio wave signal processed by the transmission processing unit,
The transmission device includes a transmission synchronization processing unit that synchronizes the transmission timing of the content data among all the transmission devices in the service area. The transmission device according to claim 12, wherein
Content data storage means for storing data of content distributed to the portable mobile terminal in the service area,
The content data storage means is a storage medium that can be inserted into and removed from the transmission device,
The transmission apparatus characterized in that the content data storage means stores content data that has been subjected to compression and encoding processing in accordance with a standard for the portable mobile terminal.

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