JP3601969B2 - Wide area data distribution system using satellite - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a satellite-based wide area data distribution system that distributes multi-channel data to a large number of receiving stations via satellites, and in particular, receives data locally at some of the receiving stations due to rainfall or the like. The present invention relates to a wide area data distribution system using a satellite provided with a backup control function and a line when a failure or unreceivable situation occurs.
[0002]
[Prior art]
In a data distribution system using satellites, if there is rainfall, snowfall, or the like, the signal level of a received radio wave is extremely reduced, and a data reception failure or a failure to receive data occurs. This poor data reception or inability to receive data usually lasts for a long time of several hours or more, and is one of the important issues in a wide area data distribution system using satellites. Therefore, various proposals have conventionally been made as this measure.
[0003]
Among them, the simplest solutions are (1) increase the transmission power on the satellite side and (2) increase the diameter of the receiving antenna in order to keep the level of the received radio wave at a sufficient value even in rain. There are measures.
[0004]
However, the problem (1) is related to the performance of the satellite, and it is difficult to take an immediate countermeasure, and a problem of radio interference between satellites also occurs. In the case (2), since the diameter becomes large, a problem of an installation place and an installation method occurs.
[0005]
In addition, (3) there is a measure to lower the data rate without changing the level of the received radio wave. However, since it extends to a change in the communication method, it cannot be easily adopted. In addition, since it is difficult to predict the degree of rainfall, it is necessary to set a large margin in this measure (3), and waste is increased in cost and the like.
[0006]
Therefore, as another method, a data retransmission method has been proposed. Typical examples of the conventional data retransmission method include a cyclic delivery method that interpolates missing data by periodically circulating and transmitting data, and transmitting the data when the receiving side detects data loss. There is known a data retransmission request method for interpolating missing data by contacting a station and transmitting the missing portion again.
[0007]
However, in these conventional data retransmission methods, in the case of the cyclic delivery method, the time corresponding to the cycle is used, and in the case of the missing data retransmission request method, the time from the request to the reception of the retransmission data. However, there is a problem that each of them is required as an interpolation time for missing data, and lacks real-time data. A more fundamental problem is that unless it is rainy and unreceivable, no retransmitted data can be received during that period.
[0008]
In order to solve this problem, as shown in JP-A-3-58632, JP-A-9-36790 and JP-A-9-64801, a satellite line is connected to each receiving station by another. Providing a line switching device for switching to the receiving station, switching the satellite line at the master station or each receiving station, and receiving data from the other receiving station via the ground line, a backup method using the ground line has been proposed. I have.
[0009]
However, the above-mentioned conventional backup method using a terrestrial line can only switch to a predetermined partner, so the probability of successful backup is low, and it is not suitable for a wide area distribution system.
[0010]
Furthermore, in the above-mentioned conventional backup method using a terrestrial line, both the control of switching the receiving station and the transmission of data after the switching are performed through the terrestrial line. There was a problem of getting heavy.
[0011]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a data distribution system that solves the problems of the above-mentioned various conventional techniques.
[0012]
A more specific object of the present invention is to enable a receiving station that has become temporarily unreceivable due to rainfall or the like to transmit received data from a receiving station in a receivable area or condition, thereby enabling a satellite link to be transmitted. It is an object of the present invention to economically provide a data distribution system capable of reliably acquiring desired data by a receiving station that cannot receive or poorly receive data from the Internet.
[0013]
[Means for Solving the Problems]
The present invention provides a data distribution system using a satellite including a data transmitting station, a satellite, and a plurality of receiving stations each including an antenna for receiving radio waves from the satellite and a receiving device. A center station means connected to a transmitting station and performing reception backup control of the plurality of receiving stations is provided, and the center station means and the plurality of receiving stations are accommodated in a public network and can be connected to each other, When a certain receiving station temporarily receives or cannot receive data via satellite due to rainfall or the like, from the center station means, the receiving station which cannot receive or receives the data of the channel desired by the receiving station is received. Control information for recruiting and selecting a receiving station capable of receiving data is distributed via a satellite, and the selected receiving station and the unreceivable or poor reception receiving station are used for the public line. By connecting Te, the unreceivable or poor reception receiving station, there is provided a data distribution system capable of acquiring a desired data in real time.
[0014]
The data distribution systems according to the features of the present invention are listed below.
According to one aspect of the present invention, there is provided a data distribution system using a satellite including a data transmitting station, a satellite, and a plurality of receiving stations each including an antenna for receiving radio waves from the satellite and a receiving device. A ground station connected to the data transmitting station and performing reception backup control of the plurality of receiving stations is provided on the ground, and the center station and the plurality of receiving stations are accommodated in a public network, and are mutually connected. A wide area data distribution system using a connectable satellite is provided.
[0015]
According to another feature of the present invention, there is provided a data distribution system using a satellite including a data transmitting station, a satellite, and a plurality of receiving stations each including an antenna for receiving radio waves from the satellite and a receiving device. The data transmitting station has a function of performing backup control of reception of the plurality of receiving stations, and the data transmitting station and the plurality of receiving stations are housed in a public line network, and are capable of being connected to each other. Is provided.
[0016]
According to another feature of the present invention, a data transmission station, in the data distribution system using satellites composed of a plurality of receiving stations an antenna and a receiving device each receives a radio wave from a satellite, before A center station that is connected to the data transmitting station and performs backup control of reception of the plurality of receiving stations, and this center station and the plurality of receiving stations are housed in a public network and can be connected to each other; The receiving station from which distribution data via the satellite has become temporarily unreceivable requests the center station via the public network to perform reception backup control, and receives the reception backup control request from the center station. guards, via the satellite, and inquires about the received backup controllable receiving station selects one receiving station, via the satellite, and notifies the selected receiving station, which is the selected Station, via said public network, the successfully received data to the non-reception station received via the satellite, a wide area data distribution system using a satellite to transmit is provided.
[0017]
According to still another aspect of the present invention, a data transmission station, in the data distribution system using satellites composed of a plurality of receiving stations an antenna and a receiving device each receives a radio wave from a satellite, The data transmitting station has a function of performing backup control of reception of the plurality of receiving stations, the data transmitting station and the plurality of receiving stations are accommodated in a public network, and can be connected to each other, and the satellite The receiving station that has become temporarily unreceivable of the distribution data transmitted through the public data line requests the data transmitting station to perform receiving backup control via the public line network, and receives the request for the receiving backup control. via the satellite, query the received backup controllable receiving station selects one receiving station, via the satellite, and notifies the selected receiving station, the selection of Receiving station via the public network, the successfully received data to the non-reception station received via the satellite, a wide area data distribution system using a satellite to transmit is provided.
[0018]
Hereinafter, a data distribution system according to the present invention will be specifically described with reference to an embodiment shown in the drawings.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
First, a satellite data distribution system as a background of the present invention will be described.
[0020]
A satellite data distribution system is a system for distributing data using a satellite from a network between offices of a company to individuals or homes, and a consumer (receiver) transmits information of the received data to a digital tuner. It is displayed on a receiving terminal such as a personal computer with a built-in board.
[0021]
With this satellite data distribution system, not only mere data but also electronic media information can be provided to consumers from the network between offices of a company to the individual level.
[0022]
In addition, the personal computer to receive data that has already spread, by being used as a display terminal, as well as dissemination of this system is easy, it is expected that the new market large-scale is born. That is, if this system is used at the home or individual level, the spread will accelerate, and the market will further develop based on the spread of personal computers, and has the potential to become a large market.
[0023]
FIG. 1 shows a system configuration of a satellite data distribution system according to the present invention. This system is roughly divided into three subsystems, namely, a production system 1, a distribution system 2, and a consumption system 3.
[0024]
The production system 1 is constituted by a production station 4 owned by a content manufacturer or an electronic information maker, and the distribution system 2 is constituted by a transmission station 5 owned by an electronic information distribution / distribution company. The data produced by the content maker or the electronic information maker at the production bureau 4 is converted by the electronic information distributor / distributor into electronic information in a format prescribed by the present system. It will be delivered.
[0025]
Since the consumption system 3 is a feature of the present invention, its configuration will be described in detail with reference to FIGS.
[0026]
As shown in FIG. 1, the consumption system 3 includes a plurality of receiving stations 31A1 to 31An and 31B1 to 31Bm (m and n are positive integers and correspond to the number of receiving stations. The reason for dividing into A and B will be described later. ), And a line 32 by radio waves transmitted from the satellite 6 to the receiving stations 31A1 to 31An and 31B1 to 31Bm via a satellite, and a one-to-k (k = 1, 2,...) And a center 34 connected to the public network.
[0027]
FIG. 2 illustrates an example of the receiving station 31Ai as a configuration example of the receiving stations 31A1 to 31An and 31B1 to 31Bm. The configuration shown in FIG. 2 is basically common to all the receiving stations 31A1 to 31An and 31B1 to 31Bm, and includes an antenna 31Ai1 for receiving data by radio waves from a line 32 from a satellite 6, and a receiving device. , A digital tuner board 31Ai2 embedded in a personal computer and a personal computer 31Ai3 in which it is embedded.
[0028]
The personal computer 31Ai3 mainly includes a personal computer main body 31Ai0. A telephone modem 31Ai4 is connected to the personal computer main unit 31Ai0, and is connected to a public network line 33. The personal computer 31Ai3 is also provided with a display 31Ai5 and a storage device 31Ai6, and can display, use, and record data.
[0029]
Using the configuration shown in FIG. 2, the receiving station 31Ai transmits the data received from the satellite line 32 to another receiving station by transmitting the data to the terrestrial public network line 33, or conversely, to the public network. Data can be received from another receiving station via the line 33. In this embodiment, the communication between the receiving stations, which is performed through the public network line 33, is one-to-one, and the other party is specified by a telephone number as in a normal telephone.
[0030]
As described above, in the consumption system 3 according to the present invention, two lines having different data rates of the satellite line 32 and the terrestrial public line 33 are used for data reception at each receiving station.
[0031]
Returning to FIG. 1, the satellite line 32 is a line using radio waves from the satellite 6, and transmits information multiplexed by the transmitting station 5 to a plurality of receiving stations 31 A 1 to 31 An and 31 B 1 in the consuming system 3 via the satellite 6. To 31Bm.
[0032]
The line 32 from the satellite 6 to the consumer system 3 is a multiplexed high-speed data line for the purpose of high-speed data batch distribution over a wide area.
[0033]
That is, many channels are multiplexed and distributed on the line 32, and the receiving stations 31A1 to 31An and 31B1 to 31Bm each select, contract, and use one or more channels among them. In this case, one receiving station generally uses some of the channels multiplexed, rather than receiving and using all the data multiplexed on the line 32.
[0034]
More specifically, the data from the satellite 6 includes a number of channels ch1 to chp multiplexed. p is usually a numerical value on the order of 100 to 1000. Here, the channel is a unit of a set of data that is simultaneously distributed, such as one program. Which channel each receiving station receives is random, but only one channel can be received at a time.
[0035]
At each receiving station, the data of the channel specified by the user among the data received through the antenna is recorded on the personal computer and displayed.
[0036]
The rate at which a single receiving station obtains data is much lower than what is being delivered. For example, even if the line 32 has a data rate of 30 Mbps, if the channel used by a certain receiving station is, for example, 64 kbps, the data rate to be acquired is as if the receiving station has a data rate of 64 kbps. Is equivalent to that transmitted by
[0037]
The satellite line 32 includes unstable and uncertain elements in reception, such as interruption due to rainfall.
[0038]
On the other hand, the line 33 is a public network line, and in this embodiment, a 64 kbps ISND line is used. The feature of the public network line 33 is that the data rate is about 64 kbps, which is small for the satellite line 32 and one-to-one communication. For this reason, it is inappropriate in terms of cost to distribute the information to a wide area at one time, but it is certain in this sense because there is no influence of rainfall or the like.
[0039]
Hereinafter, the data receiving procedure according to the present invention will be described in detail according to the flow of FIG.
[0040]
1. Backup data reception request (step S310 in FIG. 3)
Now, the transmitting station 5 creates transmission data (step 1), transmits the data to the satellite 6 for a number of receiving stations (step 2), distributes the data (step 3), and receives the receiving stations 31A1 to 31An. 31B1 to 31Bm, but the receiving stations 31A1 to 31An cannot receive data due to rain (step 3A) (step 4A). It is assumed that there is (step 3B) and that reception is possible (step 4B).
[0041]
Among the receiving stations 31A1 to 31An that cannot receive data from the satellite line 32, the station that requests the reception of the backup data sets the channel number ch- or the like desired to be received as request information (step 5A), and uses the public network line 33. (Step 6), the center 34 is contacted by e-mail or the like (step 7).
[0042]
It is not necessary for all receiving stations 31A1 to 31An that cannot receive the backup data to make a request, and only the desired receiving station makes the request.
[0043]
At this time, it is conceivable that communication is concentrated at the center 34, but by increasing the number of receiving lines of the center 34, it is possible to cope with the simultaneous multiple reception. Further, since this data is very small, at most about several tens of bytes, and one communication time is very short, data from many stations can be received serially in a short time.
[0044]
2. Call for a backup data supply station (step S320 in FIG. 3)
The center 34 creates the table TB1 shown in FIG. 4 in a memory not shown in FIG. 1 based on the data request information from the receiving stations 31A1 to 31An acquired as described above (8).
[0045]
As shown in FIG. 4, the table TB1 includes data reception request station information A40 and reception backup station area information B40.
[0046]
As described above, the data reception request information A40 is information on the station that has requested data backup reception among the stations A that cannot be examined via the satellite line 32 due to rainfall or the like, and is acquired by the center 34 through the public line 33. It is created based on the data obtained. That is, the data reception request information A40 is a receiving station name A 41, receiving station ID A 42, the receiving station the telephone number A 43 and the backup request channel number A 44.
[0047]
On the other hand, the reception backup station area information B40 is information for specifying, for each reception station A, the area of a station that performs backup reception for the reception station A in the data reception request station information A40. It is composed of a combination of an outside number and a local number.
[0048]
Returning to FIG. 3, the center 34 transmits the data of the table TB1 of FIG. 4 to the transmitting station 5 (step 9) using the public network line 33 (step 10), and receives the data at the transmitting station 5 (step 11). ).
[0049]
The transmitting station 5 transmits the received data of the table TB1 to the satellite 6 using one channel of the satellite line 32 or as ancillary data of a certain channel of the satellite line 32 (step 12), and all the receiving stations 31A1. To 31An and 31B1 to 31Bm (step 13B).
[0050]
The data corresponding to the table TB1 in FIG. 4 can be obtained only by the receiving stations 31B1 to 31Bm that can receive data from the satellite line 32 at that time (14B), and cannot be received by the receiving stations 31A1 to 31An located in the area where it is raining. (14A). The table TB1 has a data amount of less than 1 MB (megabyte), and the time and cost are small even if the public network line 33 is used.
[0051]
The data in the table TB1 received by the receiving stations 31B1 to 31Bm is determined whether each receiving station can supply backup data by itself. If the backup data can be supplied, a response indicating that the data can be supplied is returned. The data is transmitted to the center 34 via the public network line 33 (16) (15B). That is, the receiving stations 31B1 to 31Bm that have received the data of the table TB1 transmit the channel number ch− that can be received by the own station and can supply the data to the center through the public network line 33 in accordance with the reception content of each receiving station. Contact 34 by e-mail or the like. This step (15B) does not need to be performed by all the receiving stations 31B1 to 31Bm, and only the desired receiving station may be performed.
[0052]
In the above description, the “channel number ch- capable of supplying data” is the number of a channel that is scheduled to be received and that can transmit data of the channel using the public network line 33 at the same time as receiving.
[0053]
The center 34 receives the channel number information from the receiving stations 31B1 to 31Bm (step 17).
[0054]
Here, the area designation code B41 of the data supply station in FIG. 4 will be described. Due to the wide-area nature of the satellite-based data distribution system, the area where rainfall becomes unreceivable due to rainfall or the like is small compared to the entire receiving station. In other words, the number m of the receiving stations 31B1 to 31Bm in the non-rain area where the satellite line data can be received is much larger than the number n of the receiving stations 31A1 to 31An in which the reception is poor or impossible in the rain area.
[0055]
Since the data from the receiving stations 31B1 to 31Bm is very small, about several tens of bytes, one communication time to the center 34 is very short. However, compared to the case where the communication is received only for the receiving stations 31A1 to 31An. When receiving data with a limited number of lines at the center 34, much more time is required. It is not economical to further increase the number of lines in the center in order to reduce this time.
[0056]
Therefore, in the present invention, by limiting the area of the receiving stations 31B1 to 31Bn to be communicated, the communication is concentrated on the center 34 and the reception at the center 34 is prevented from being saturated. Hereinafter, an example of this area limitation method will be described.
[0057]
In the example shown in FIG. 4, the target receiving stations 31B1 to 31Bm are limited in area under the following conditions (1) to (3).
[0058]
(1) Set the area where reception is possible for the required time based on weather information.
[0059]
(2) Consideration is given so that the line charge of the public line network does not increase in an area relatively close to the receiving stations 31A1 to 31An.
[0060]
(3) The number m of the target receiving stations 31B1 to 31Bm is limited to be several times (for example, twice) the number n of the receiving stations 31A1 to 31An.
[0061]
If the receiving stations 31A1 to 31An are dispersed in some areas, the receiving stations 31B1 to 31Bm must also be dispersed and designated.
[0062]
In the embodiment, the designation of the area limitation based on the above conditions is performed by the local area code and the area code of the telephone number. FIG. 4 shows such a case where the area limitation information is added to the reception data requesting station information.
[0063]
3. Determination of backup data supply station (step S330 in FIG. 3)
Based on this information, the center station 6 generates a table TB2 shown in FIG. 5 in which the desired channel numbers such as the addresses and telephone numbers of the receiving stations 31A1 to 31An and the receiving stations 31B1 to 31Bm and the currently received channel number are associated. It is created (step 18).
[0064]
A method for creating the table TB2 will be described below. In this table TB2, receiving station information A50, receiving station name A51, receiving station ID A52 and telephone number A53, and receiving station information B50 capable of supplying backup data are received as receiving station information A50 that cannot be received and for which backup data is requested to be received. The station name B51, the receiving station ID B52, the telephone number B53, and the association of the channel number C51 as the common information C50 are recorded.
[0065]
For example, a data transmission instruction is written by associating the receiving station 31Ai with the receiving station 31Bj capable of receiving the same channel that the receiving station 31Ai desires to receive and supplying data to. At this time, a plurality of receiving stations 31Ai desire the same channel, and a plurality of receiving stations 31Bj can supply data. However, as far as possible, these receiving stations 31Ai and receiving stations 31Bj perform one-to-one communication. It is desirable to instruct For this purpose, the range of area designation of the receiving stations 31B1 to 31Bm is broadly determined so that the number of the receiving stations 31B- is sufficiently larger than the number of the receiving stations 31A-. With this determination, even if a receiving station 31Bj that cannot supply data occurs, there is no problem in the present system.
[0066]
However, since the area designation is based on prediction, the reverse situation may occur, and the receiving station 31Ai to which data is not supplied may occur. In this case, the number of stations performing one-to-two (transmitting side 1 to receiving side 2) communication is sequentially increased. If there is still a shortage, the operations are sequentially performed in the order of 1: 3, 1: 4.
[0067]
Returning to FIG. 3, the center 34 transmits the data of the table TB2 in FIG. 5 to the transmitting station 5 to the transmitting station 5 using the public network line 33 (step 20) (step 19). This table TB2 also has a data amount of less than 1 MB, and the time and cost are small even if the line 33 is used.
[0068]
The transmitting station 5 distributes the data of the table TB2 using one channel of the satellite line 32 or as ancillary data of a certain channel. This table TB2 distributed using the satellite line 32 is distributed to all the receiving stations 31A1 to 31An and 31B1 to 31Bm (step 23A) (step 23B), but only the receivable receiving stations 31B1 to 31Bm can be obtained. (Step 24B).
[0069]
3. Supply of backup data (step S340 in FIG. 3)
The receiving stations 31B1 to 31Bm look at the table TB2 and transmit the backup data via the public network line 33 to the receiving station 31A- instructed to transmit the data (step 24B). This is one-to-one communication between the receiving station 31Bj and the receiving station 31Ai via the public network line 33, and does not involve the center 34, which is one of the features of the present invention.
[0070]
This backup data is transmitted, for example, at a data rate of 64 kbps from the receiving station 31Bj to the receiving station 31Ai.
[0071]
In the first embodiment shown in FIG. 1, the case where the center 34 is provided separately from the transmitting station 5 is shown. However, as shown in the second embodiment in FIG. 5, and an integrated configuration is also possible.
[0072]
【The invention's effect】
As described above, according to the present invention, by transmitting data received from a receiving station in a receivable area and conditions to a receiving station temporarily unreceivable due to rainfall or the like, It becomes possible for a receiving station that cannot receive data to acquire data.
[Brief description of the drawings]
FIG. 1 is a block diagram of a satellite data distribution system according to a first embodiment of the present invention.
FIG. 2 is a configuration diagram of a receiving station in FIG. 1;
FIG. 3 is a diagram showing a procedure flow according to the present invention.
FIG. 4 is a diagram showing a table 1 distributed from a center according to the present invention.
FIG. 5 is a diagram showing a table 2 distributed from the center according to the present invention.
FIG. 6 is a block diagram of a satellite data distribution system according to a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Production system, 2 ... Distribution system, 3 ... Consumption system, 4 ... Production system, 5 ... Transmitting station, 6 ... Satellite, 31A ... Receiving station, 31B ... Receiving station, 32 ... Satellite line, 33 ... Public communication network, 34 ... Center, TB1 ... Table 1, TB2 ... Table 2

Claims (4)

A data transmission station, in the data distribution system using satellites composed of a plurality of receiving stations an antenna and a receiving device each receives a radio wave from a satellite,
Connected before Symbol data transmission station is provided with a center station that receives backup control of the plurality of receiving stations,
The center station and the plurality of receiving stations are accommodated in a public line network and can be connected to each other ,
The receiving station in which the distribution data via the satellite has become temporarily unreceivable requests the center station for reception backup control via the public network ,
Center station that received the receive backup control request through the satellite, and inquires about the received backup controllable receiving station selects one receiving station, via the satellite, the receiving station selected Notify,
The selected receiving station, via said public network, the successfully received data, wide-area data distribution system to unreceivable receiving station using a satellite, characterized in that it Send via the satellite . 2. The center station receiving the request for the reception backup control notifies the selected reception station of at least a telephone number and a channel number of the reception station that has requested the reception backup control. Wide-area data distribution system using the satellites described. A data transmission station, in the data distribution system using satellites composed of a plurality of receiving stations an antenna and a receiving device each receives a radio wave from a satellite,
The data transmitting station has a function of performing reception backup control of the plurality of receiving stations ,
The data transmitting station and the plurality of receiving stations are housed in a public line network and can be connected to each other ,
The receiving station in which the distribution data via the satellite is temporarily unreceivable requests the data transmitting station for reception backup control via the public network ,
The data transmitting station that has received the request for the reception backup control queries the reception backup-controllable reception station via the satellite, selects one reception station, and sends the selected reception station to the selected reception station via the satellite. Notify,
The selected receiving station, via said public network, the successfully received data, wide-area data distribution system to unreceivable receiving station using a satellite, characterized in that it Send via the satellite .   4. The data transmitting station that has received the request for the reception backup control notifies the selected receiving station of at least a telephone number and a channel number of the receiving station that has requested the reception backup control. Wide-area data distribution system using the satellites described.

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