JP2003318794A - Method for receiving signal from artificial satellite, receiver of signal from artificial satellite, transmitting method, and information system for exchanging information with artificial satellite - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an effective satellite switching means for preventing degradation in throughput at non-switching times, in a communication/broadcast system using an orbit satellite by switching and using the satellites used for services. <P>SOLUTION: Reference numeral 5505 denotes a transmission/reception pattern of a satellite 1 before being switched, and 5506 denotes a transmission/reception pattern of a satellite 2 after being switched. In this case, the types of data are classified into one 5507 for which a short time response is required and the other one 5508 for which it is not required. The data for which the throughput must be kept constant, such as steaming or broadcasting, is included in 5507. A section sandwiched with inverted triangles 4, 5 is a satellite switching period. The transmission period of 5508 for which a short time response is not required is overlapped on the satellite switching period. In this way, the satellites can be switched without impairing the communication quality of the data for which the throughput must be kept constant, such as streaming or broadcast. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to communications using orbiting satellites, and the main operating satellites are switched over in time.
The present invention relates to a satellite switching method for 4-hour operation, and a method and device for performing handover between a plurality of beams.

[0002]

2. Description of the Related Art A technique for communicating or broadcasting using artificial satellites orbiting the earth has been attracting attention. With this technique, communication or direction is possible over a wide range while being relatively away from the restraint of the ground object.

Examples of artificial satellites include geostationary satellites that move similarly to the rotation of the earth. However, geostationary satellites are placed on the equator, and when trying to receive at a location away from the equator, the so-called elevation angle is low, and the signal is blocked by tall buildings or natural objects. Therefore, a technique for communicating or broadcasting using an artificial satellite that moves in an elliptical orbit has been devised.

An artificial satellite moving in an elliptical orbit moves at a speed relative to the rotation of the earth. Therefore, with the movement, the process of approaching the service area, moving away, and approaching the service area again is repeated. When an artificial satellite is far from the service area, communication or broadcasting becomes difficult. Therefore, a plurality of artificial satellites are arranged so as to alternately approach the service area. Such a technique is described in, for example, Japanese Patent Laid-Open No. 11-034996.

[0005]

When a geostationary satellite is used, there is no switching of satellites. However, in the communication or broadcasting using the elliptical orbit, there is a possibility that a peculiar processing such as disconnection / reconnection of the line is concentrated at the time of switching satellites, resulting in congestion. Orbiting satellites are elliptical (or high orbit) satellites (HEO) and low / medium orbit (LEO) satellites.
・ MEO), low / medium orbit satellite (LEO ・ ME
O) requires a frequent switching because the orbital cycle is short (these are all included in non-geostationary satellites (hereinafter the same)). Also, among high-orbit satellites (HEO), those that are synchronized with the rotation cycle of the sphere will transfer in a synchronized orbit. However, since a high earth orbit satellite (HEO) has a relatively long orbiting cycle, preparing for satellite switching that occurs relatively infrequently causes a decrease in communication efficiency during non-switching. Further, compared to the LEO / MEO system, a high-orbit satellite (HEO) has a relatively large number of accommodated channels per satellite, and these channels must be switched at the same time when the satellite is switched. An object of the present invention is to enable efficient communication or communication when switching satellites.

On the other hand, in communication or broadcasting using artificial satellites, a service area is divided into a plurality of areas, and a beam spot is irradiated to each of the divided areas to provide a service. Regarding the stability of the beam spot, for example, in geostationary satellites, the satellite orbit was a circular orbit, so there was almost no effect of attitude control. Compared with conventional satellites,
For example, since the satellite is always unstable such as shaking, the range of the beam radiated to the ground fluctuates by about several tens km. Therefore, in satellite communication using the high frequency band, the number of satellite beams is large, so the effect becomes significant.However, when inter-beam handover is considered, there is a problem that adjacent beams do not overlap each other, and communication quality increases. Will decrease. An object of the present invention is to make it possible to improve the quality of communication or broadcasting.

[0007]

At least one of the above objects
In order to achieve one of the above, the present invention provides information for a predetermined satellite signal from being substantially not received (transmitted) until the alternative satellite signal is substantially received (transmitted). , Configured to transmit in advance from a predetermined artificial satellite.

Alternatively, in a state where a signal of a predetermined satellite can be received, a signal is received (transmitted) from a substitute artificial satellite, and processing for switching from the predetermined artificial satellite to a substitute artificial satellite is performed.

Alternatively, after the reception (transmission) from the alternative artificial satellite becomes possible, the missing information in the received information from the alternative artificial satellite is supplemented.

Alternatively, after the reception (transmission) from the alternative artificial satellite becomes possible, the reception is switched to a predetermined artificial satellite.

Alternatively, when the signal from the alternative artificial satellite cannot be received (transmitted), the signal from the alternative artificial satellite is received (transmitted) via a predetermined artificial satellite.

Alternatively, a signal having a frequency corresponding to the geographical condition in the service area is received (transmitted) from the artificial satellite, and the signal from the alternative artificial satellite is received (transmitted) based on the frequency. Configured.

Alternatively, the present situation in receiving the radio signal is judged or the future situation is estimated, and the radio signal from the artificial satellite is changed so as to improve the reception state based on the decision or the estimation.

Alternatively, the radio signal radiated to at least one area is received (transmitted) from the radio signal radiated from the artificial satellite so as to cover different service areas, and the reception status of the future radio signal is received. It is configured such that one of throughput and reception improvement is selected based on the estimation.

Alternatively, the radio signal radiated to at least one of the radio signals radiated from the artificial satellite to cover the service area is received (transmitted), and the reception status of the future radio signal is Guess and configure based on guess about receive delay, throughput, reliability or tariff.

Alternatively, a signal containing the information of the predetermined satellite and the information of the artificial satellite to be replaced is received (transmitted) from a predetermined satellite among the artificial satellites, and the satellite is changed from the predetermined artificial satellite based on the received information. It is configured to switch reception.

Alternatively, the arithmetic processing is performed based on the received signal, and the reception state from the artificial satellite in the service area is calculated, and the information regarding the reception state is displayed based on the calculation.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. This embodiment relates to communication or broadcasting using an artificial satellite. First, the arrangement of the artificial satellite will be described. A preferred example will be described by using a synchronous satellite (synchronous with the rotation period of the earth), but a high earth orbit satellite (HEO)
Can be used. Furthermore, it is also possible to use it for an orbiting satellite (medium orbit satellite, LEO, MEO). These orbits are collectively called non-geostation orbits.

(1) Orbit of artificial satellite In this orbital arrangement example, there are three orbital planes as shown in FIG. 1, and one artificial satellite 60, one artificial satellite 61 and one artificial satellite 62 are arranged on each orbit. ing. The artificial satellite 60, the artificial satellite 61, and the artificial satellite 62 orbit 63, the orbit 64, and the orbit 65 respectively in about 24 hours. The orbit period of the artificial satellite 60, the artificial satellite 61 and the artificial satellite 62 is about 24 hours, the perigee argument is in the range of 180 degrees or more and 360 degrees or less, and the eccentricity is in the range of less than 0.24, and The orbit inclination angle is in the range of 37 degrees or more and 44 degrees or less, or the eccentricity is in the range of 0.24 or more and 0.35 or less, and the orbit inclination angle is greater than 40 degrees and 44 degrees or less. It is within the range. The ascending node RAs of the orbits of the three satellites are 120 degrees apart as shown in FIG. 1, and the apogee of each orbit is set to appear at an appropriate position above or near Japan. As for the positional relationship of the respective artificial satellites in their respective orbits, when the artificial satellite 60 is at a perigee on its orbit 63, the artificial satellite 61 is on its orbit 64 in the immediate vicinity delayed by one third of the orbit period. The satellite 6 is located at a position where a point separation angle is taken.
No. 2 is arranged on the orbit 65 so as to be at a position where the proximate deviation angle is obtained by advancing by one third of the orbit period. In addition,
The case where the number of orbital planes is three has been described as an example, but the number of planes may be four or more.

(2) Example of service form FIG. 2 shows an example of service form when applied to satellite communication / satellite broadcasting using such a non-geostationary satellite. As shown in FIG. 2, in this system example, a non-geostation satellite group 5001
And the satellite tracking and control operation station 5003 of this non-geostationary satellite group.
A broadcasting station / communication center station 5007, a mobile station 5010 such as an automobile that is a user of this system, and a fixed station 5011 such as a general household who is a user of this system. The relay facility 5013 may be added as a component.

The uplink from the mobile station 5010 as a user may be via the non-geostation satellite group 5001 or may be via the relay facility 5013 and the non-geostation satellite group 5001. (PHS) may be used. Further, the uplink from the fixed station 5011 of a general household or the like may be via the non-geostation satellite group 5001, or may be via the relay equipment 5013 and the non-geostation satellite group 5001. May be.

The non-geostationary satellite group appears in lieu of the sky in Japan and alternately provides services. However, if the number of satellites serving Japan at the same time is always one, the inter-satellite group Although the switching needs to be performed in an instant, the application of the present invention allows a user located anywhere in Japan to continue to receive the communication / broadcasting service at the timing of switching the satellite without any interruption. . Also, the number of satellites that provide service to Japan at the same time need not be one.

The mobile station 5010 is moving in Japan and may move across the communication / broadcasting beams of the satellite 5001 side. However, the application of the present invention makes the communication / broadcasting transparent to the user. You can receive service seamlessly.

As a supplementary explanation with reference to FIG. 44, in the broadcasting station / communication center station 5401, the content 5402 transmitted as the content of broadcasting / communication is the data processing facility 540.
After being given the protocol of the present invention in 3, the transmission equipment 5 having functions of baseband signal processing, modulation, amplification, etc.
After being transmitted to the transmitting antenna 5405 via 404, the satellite 5
Sent to 407. The transmitted content is relayed and transmitted by the satellite 5407 to the fixed station 5409 such as a general household or the mobile station 5410 such as an automobile. In addition, the relay facility 5413 may be used.

(3) Example 1 of Satellite Switching System With regard to the service form of such an artificial satellite, switching of hygiene will be described next. By the way, generally, orbiting satellites are high orbit hygiene (HEO) and medium orbit satellites (LEO / ME).
O), but in this embodiment, high orbit hygiene (HE
O). That is, low and medium orbit satellites (LEO
Since the communication method using (MEO) is premised on frequent switching, the communication efficiency of the non-switching is low, and it cannot be applied as it is to the communication system of the present invention premised on services by a small number of satellites. Because there is no. FIG. 3 shows an example of scheduling transmission / reception of long response time data during the satellite switching period. Reference numeral 5505 is a transmission / reception pattern of the satellite 1, and reference numeral 5506 is a transmission / reception pattern of the satellite 2. In the following description, satellite 1 will be used unless otherwise specified.
Indicates the hygiene before switching, and the satellite 2 indicates the satellite after switching. Therefore, in the case of a satellite configuration with three satellites, the same satellite depends on the switching cycle, and the same satellite is "Satellite 1" or "Satellite 2"
Play the role of. Of these scheduling, 55
A copy 07 shows an allocation time for transmission / reception of short response time data, and a reference numeral 5508 shows an allocation time for transmission / reception of long response time data. Reference numeral 5509 indicates a state of being inactive before and after the switching. Inverse triangle 1 to 5511 of 5510
Up to the inverted triangle 7 indicates the signal type and satellite switching timing. Here, the short response time data refers to data that needs to be transmitted and received with a constant data amount within a fixed time, such as streaming distribution and broadcasting, or data that requires an immediate response. On the other hand, the long response time data is data that requires less immediate response such as transmission / reception of traffic information and various telemetry data. In this embodiment, at the time of satellite switching (the period between the inverted triangle 4 and the inverted triangle 5)
By allocating the transmission and reception of the long response time data to the satellite, the satellites can be switched while maintaining the transfer rate of the short response time data. Therefore, there is no influence on the service quality such as broadcasting and streaming due to satellite switching.

FIG. 4 shows an operation flow on the terminal side when the above embodiment is executed. In 5606, the data type switching timing is determined. Here, the timings of the inverted triangles 1 to 7 in FIG. 3 are detected. Next, in 5607, it is determined whether the type of data to be transmitted / received next is short response time data or long response time data. Here, if the next data type is scheduled for long response time data, 560
At 8, it is determined whether or not it coincides with the satellite switching timing. If it does not coincide with the satellite switching timing, the long response time data is processed 560
9. If it coincides with the satellite switching timing, data is skipped 5610. Also, when it is determined in 5607 that it is the timing to switch to the short response time data,
5611 to process short response time data.

(4) Example 2 of satellite switching system Next, an example in which beams are emitted from a plurality of satellites at different frequencies in the same area at the time of satellite switching will be described with reference to FIGS. FIG. 5 is a timing chart and FIG. 6 is an example of a beam spot. The beam spot of the satellite 1 is shown in FIG.
The same (b) shows the beam spot of the satellite 2, and is assumed to be a pattern when the same area is irradiated.
5801-5804 is one satellite spot, 5804-58
08 is a satellite 2 spot. It is assumed that f1 and f2 represent frequencies (bands) used in each spot. The feature of this embodiment is that a period for irradiating the satellite 1 and the satellite 2 in an overlapping manner is provided when the satellites are switched (5703 in FIG. 5). At this time, the satellite 1 (satellite before switching) and the satellite 2 (satellite after switching) irradiate the same area with beams of different frequencies, so that satellite switching is smoothly performed. For example, the pos1 point (5
In 809), the beam of the frequency f1 was initially emitted from the satellite 1, but the emission of the beam of the frequency f2 from the satellite 2 is started with the satellite switching (FIG. 6B).
5810). Therefore, the terminal existing at the position of pos1 can know the point that the satellite can be supplemented even after the satellite is switched and the point that the frequency used is f2 at the stage when the communication with the satellite 1 is possible. . Therefore, before the connection with the satellite 1 is terminated, the already established f
The connection at 1 can be used to reserve a connection for the new frequency f2. This method can be operated much more efficiently than the case where a new connection is reestablished after complete switching to the satellite 2. In this example, for the sake of explanation, 2
Although different frequencies are used and the same frequencies are alternately arranged, more frequencies may be used and the intervals at which the same frequencies appear may be increased. Next, an example of the operation sequence of the above-described embodiment will be shown using FIGS. 7 is an operation sequence when the beam of the satellite 2 can be captured during the satellite switching period, FIG. 8 is an operation sequence when the beam of the satellite 2 cannot be captured during the satellite switching period, and FIG. 9 is satellite switching It is the second example of the operation sequence when the beam of the satellite 2 can be supplemented during the period. First, in FIG. 7, 5901 indicates the terminal side and 5902 indicates the base station side. 5903 is the satellite switching period and satellite 1
And the satellite 2 is operating overlappingly. Before 5903, only satellite 1 operates and 5
After 903, it is assumed that only the satellite 2 operates. The operation here means a state in which the communication is actually used. First, it is assumed that communication was performed using the frequency f1 of the satellite 1 before the switching period 590
4. After that, the satellite switching period starts, and the satellite 2 starts operating. At this time, if the beam f2 from the satellite 2 is detected 5905, the frequency f1 of the satellite 1 is used, and the frequency f2 of the satellite 2 is used.
The reservation process 2 is performed 5906. After the satellite switching period ends, communication is performed using the frequency f2 of the satellite 2 5907.
As shown in FIG. 8, when the beam from the satellite 2 cannot be captured during the satellite switching period 6005, the frequency f1 of the satellite 1 is used while the communication with the satellite 1 is available within the satellite switching period. Perform termination processing. By this explicit termination process, the connection can be released before the base station side waits for timeout, so that the server resources and radio band resources on the base station side can be used without waste. The terminal side also knows that the satellite 2 is not available before waiting for the timeout after switching the satellites, and therefore, it is possible to prepare for the next process to be performed at an early stage. For example, the session can be shortened by limiting only the processing that can be completed within the time period during which the satellite 1 can be used within the satellite switching period, and other communication means (communication media other than satellite)
By making the request for the switching process to the satellite 1 before the disconnection with the satellite 1, it is possible to establish an apparently seamless session. Of course, if the line with satellite 2 is restored 60
07, 600 requesting connection and restarting communication if necessary
8. The sequence of FIG. 9 is, before the satellite switching period ends,
This is an example of starting to use the satellite 2 frequency f2 which is to be used after switching 6106. Of course, in this state, satellite 1 and satellite 2
Both may be used simultaneously. FIG. 10 is an operation flow on the terminal side in the above embodiment. During the satellite switching period 6201, try to detect the frequency of the satellite after switching 6202. If it can be detected, the next frequency of the satellite after switching is reserved via the satellite before switching 6203, and then the next frequency is used to enable communication continuation 62.
04. If the frequency of the satellite after switching cannot be detected, the session is shortened or a connection request to another communication means is issued within the time when the satellite before switching can be used.
05. In addition, an explicit communication disconnection process 6 with the satellite before switching
By performing 206, resource saving on the base station side is achieved.

In this embodiment, the satellite 1 before and after satellite switching is used.
The case where the beam spot of 1 and the beam spot of the satellite 2 have the same shape has been described. In reality, since it is difficult to make the beam spots have the same shape, the frequencies are arranged so that the spot shapes may be different between the satellites before and after the switching. At this time, a frequency distribution format is adopted in which a cycle in which the same frequency appears is long so that the same frequency does not irradiate the same portion. Furthermore, the satellite 1 and the satellite 2 do not irradiate all the beam spots at the same time at the time of switching, and the satellite 2 partially irradiates the beam so that a region with a high demand locally can be selectively irradiated with different frequencies. It is also possible to give good handover for many connections.

(5) Example 3 of satellite switching system FIG. 11 shows a timing chart of an embodiment in which handover is gradually performed in a time division manner.

Reference numeral 6401 is a slot for short response time data of the satellite 1, 6402 is a slot for long response time data of the satellite 1, 6403 is a slot for short response time data of the satellite 2,
6404 indicates a slot of long response time data of satellite 2. The slot here is a time slot having a time length such that the satellite can be temporarily switched and synchronized with the signal of the satellite. The post-control slot is a time slot having a time length such that connection disconnection and switching to another communication means can be controlled. 6405 is a satellite switching pre-processing period, during which normal satellite 1
The beam irradiation of the satellite 2 can be performed in a time division manner. Similarly, 6406 is a satellite switching post-processing period, in which the satellite 2 normally performs beam irradiation, but the beam irradiation of the satellite 1 can be performed in a time division manner. 6407 is a satellite switching period. This embodiment does not specify whether the satellite 1 or the satellite 2 performs beam irradiation within this period. Reference numeral 6408 denotes a pre-control slot, which is a slot of satellite 2 in which 0 or more exist during the satellite switching pre-processing period. Similarly, 6409 is a post-control slot, which is a slot of satellite 1 which is present in the number of 0 or more during the satellite switching post-processing period. The feature of this embodiment is that before switching the satellite, the beam from the satellite after switching in advance is radiated for a short period of time to obtain information on the connection status with the satellite after switching, and use this information to improve communication efficiency. That is the point. Only one of the pre-switching processing period and the post-processing period may be used. The length of both periods is
It may be arbitrarily set within a period in which both the satellite 1 and the satellite 2 are simultaneously within an operable elevation angle. Regarding the position of the previous control slot, considering that various termination processing is performed using the connection established with the satellite 1 which is the satellite before switching, there is some grace rather than just before switching satellites. Set it in a safe place. Further, there may be a plurality of front control slots and rear control slots instead of one.

FIG. 12 shows a beam spot of the same embodiment. 6501 is the beam spot 1 (frequency f
1) and 6502 are beam spots 2 (frequency f
2), 6503 is the beam spot 1 (frequency f
1) and 6504 are beam spots 2 (frequency f
2). In the present embodiment, the beams of the satellites before and after the switching are irradiated in a time division manner, so there is an advantage that the beam spot shapes of the satellites before and after the switching need not be exactly matched. Also, the frequency used after switching can be known by looking at the frequency of the previous control slot. For example, regarding the point 1 of 6505, the frequency of f1 can be used before and after switching,
Regarding point 2 of 6506, since it is known that the area of the beam spot of f2 is changed from f1 before switching, using the f1 currently used during the slot period of the satellite 1 after receiving the previous control slot. A process for reserving f2 to be used after switching can be performed.

FIG. 13 is a flow chart of the satellite switching pre-processing period. During the pre-switching process period, it is determined whether the beam of the satellite 2 can be detected 6601. If the beam of the satellite 2, which is the satellite after switching, cannot be detected, the satellite 2 may be shielded. Therefore, it is unlikely that communication will be possible using satellite 2 after switching satellites.
In the control slot of the next satellite 1, a disconnection request is explicitly transmitted to save computer resources and radio band resources at the base station 6602. At this time, of course, the request for switching to another communication means may be transmitted using the control slot of the satellite 1. Similarly, the switching request may be made by using a system other than the satellite system. Thereafter, the communication on the terminal side is completed or switched to another communication means 6603. If the beam of satellite 2 can be detected during the satellite switching pre-processing period,
6604 to determine the frequency. If the result of determination is that the frequency is the same as before switching, the same frequency is used after switching 6605, and connection is continued 6606. If the result of determination is that the frequency is different from that before switching, a request to switch to another frequency is sent out 6607. After the determination of acceptance of the request 6608, if not accepted, end processing 6609 is performed to end or switch to another communication means 6610.
In step 609, if possible, other than the termination process, a session shortening process for performing only communication that can be serviced within the obtained time may be performed to normally complete and terminate the session. If the request is accepted in 6608, it is determined 6611 to continue the communication using the accepted frequency and 6612 to continue the connection.

FIG. 14 is a flow chart of the post-satellite switching processing period. During this period, the satellites already used are switched from satellite 1 to satellite 2 in terms of scheduling. Then, the satellite 2 beam detection determination is performed 6701.
If no beam of the satellite 2 is detected and communication with the satellite 2 is not possible, the disconnection request is explicitly transmitted in the post-control slot capable of connecting to the satellite 1 at 6702. , Computer resources and frequency resources on the base station side can be saved more than in the case of disconnection processing due to timeout. In such a case where communication with the satellite 2 is impossible after the satellite switching, the case where the control is not performed during the satellite switching pre-processing period, or the satellite 2 is visible within the pre-processing period, the satellite 2 is constructed after the switching. This may be the case when it becomes invisible due to being blocked by an object. After disconnection from the satellite, the communication is terminated or switched to another communication means to continue the communication 670.
3.6 If the beam of satellite 2 is detected in the determination of 6701, then the frequency of the beam is determined 670.
4. If the frequency is determined to be the frequency reserved during the satellite switching pre-processing period, the connection is continued 670.
5. If the frequency is different from the reserved frequency, a wave number allocation request is sent again 6706 in the post-control slot of the satellite 1 for the frequency of the beam of the satellite 2 that can be currently received. Next, the acceptance of the allocation request is judged 6707,
If accepted, continue 6710 using the new assigned satellite 2 frequency. If not accepted, an explicit disconnection request is sent 6708 in the post-control slot of the satellite 1 for effective use of resources.

Next, referring to FIG. 15, an example 1 of the sequence during the satellite switching pre-processing period is shown. This sequence is shown in Figure 1.
3 corresponds to the flow up to 6603. 700
Reference numeral 1 represents a terminal, and 7002 represents a base station. Reference numeral 7003 denotes a satellite number that emits a beam (a satellite that satellite 1 mainly uses before switching, and a satellite 2 that satellite mainly uses after switching). 7004 is the irradiation period of the previous control slot, 7
005 is a satellite switching section. After switching satellites,
As in 7006, the main beam irradiation satellite is switched to the satellite 2. Further, Bs1 is a beam spot irradiated by the satellite 1 and Bs2 is a beam spot irradiated by the satellite 2. Here, the terminal of interest is B before the satellite switching.
It is assumed that communication is performed using s1 7007. Next, when the previous control slot period starts and Bs2 cannot be detected 7
It is considered that the satellite 1 is visible but the satellite 2 is not visible as seen from the terminal. The term "invisible state" as used herein includes a case of attenuation due to rainfall and an abnormality of a communication system including a satellite, in addition to being in a place that cannot be physically seen. Since it was previously known at the stage of 7008 that the satellite 2 which is the main transmitting satellite after the satellite switching is invisible, the disconnection process is explicitly performed at the timing of 7009 which has the connection with the satellite 1 before the satellite switching. . This processing leads to effective use of resources on the base station side and frequency band resources. After the satellite switching, the communication with the satellite system is disconnected 7010. In 7009, a switching request to a communication means other than the quasi-zenith satellite may be performed in addition to the disconnection processing. In that case, at 7010, communication continues through other media.

Next, with reference to FIG. 16, a second example of the sequence during the satellite switching pre-processing period is shown. This sequence is shown in Figure 1.
3 corresponds to the flow reaching 6606. Unlike the former example, this sequence shows a case where Bs2 (beam via satellite 2) was detectable 7108 within the previous control slot period 7104. If the frequency detected here is the same as the frequency used in Bs1 of the satellite 1, the same frequency as the frequency before switching is used also in the communication of Bs2 by the satellite 2 after the satellite switching period 7105. And continue communication. 71 of course
As in 10, Bs1 can be continuously used before the satellite switching. In the present embodiment, the "different frequency" may be "different spread code" in the case of spread spectrum communication. In the case of time division processing, it may be'different slot '. In any case, it refers to the distinction of communication paths that can be identified as different channels by the user.

Next, referring to FIG. 17, a third example of the sequence during the satellite switching preprocessing period is shown. This sequence is shown in Figure 1.
3 corresponds to the flow to 6610. In this sequence, Bs2 (beam via satellite 2) can be detected 7208 within the previous control slot period 7204.
And the frequency that can be used in Bs2 is different from that used in Bs1. In this case, in the period 7210 in which the satellite 1 can be used again after the previous control slot, the frequency to be newly used in Bs2 is requested 7211. In response to this request, if the refusal is responded from the base station 7212, termination processing or switching request to another communication means is performed 7213. In this way, when it is possible to determine in advance that the satellite 2 is invisible after the satellite switching, communication resources can be saved by the explicit disconnection process. In addition, for example, a method of shortening the session itself to a period that can be processed before the switching, such as only transferring a file of a size in which the download is completed before the switching, can be considered.
By this process, the risk of starting a process that is interrupted midway is reduced, so that convenience for the user is also improved.

Next, with reference to FIG. 18, a sequence example 4 of the satellite switching pre-processing period is shown. This sequence is shown in Figure 1.
3 corresponds to the flow to 6612. This sequence is based on Bs1 currently used in the previous control slot.
Of the Bs2 used after the switching and the frequency of Bs2 used after the switching are detected.
7311 requesting frequency 2 and received 731
The operation at 2 o'clock is shown. When the request is accepted, Bs2 of satellite 2 is used after the satellite switching period 7305.
06, 731 to communicate at the newly acquired and accepted frequency
3. Also in this case, communication may be continued using the satellite 1 during the satellite 1 usable period 7310 after the previous control slot.

Next, referring to FIG. 19, an example 1 of the sequence during the satellite switching post-processing period is shown. This sequence is shown in Figure 1.
4 corresponds to the flow up to 6703. In the description of the sequence of the processing period after satellite switching, the state immediately before the satellite switching will be described. 7404 is a satellite switching section, and the main beam irradiation satellite is switched from 7403 satellite 1 to 7406 satellite 2 at this boundary. A post-control slot 7405 is a period during which the satellite before switching (satellite 1) temporarily emits a beam after switching satellites. Now
During the satellite 2 irradiation period after the satellite switching period, satellite 2
740 beam (Bs2) could not be detected
7. This is because the satellite 2 was visible during the satellite switching pre-processing period but became invisible after switching,
It is assumed that the switching control itself is not performed during the satellite switching pre-processing period. At this time, it is wise to avoid keeping the connection while the recovery time of the satellite 2 is unknown from the viewpoint of computer resources and radio band resources on the base station side. Therefore, in the post-control slot 7405 in which the satellite 1 before the switching can be used again after the satellite switching, the disconnection process is performed using Bs1 (beam via the satellite 1) 7408. After the post-control slot ends, the communication is ended or switching to another communication means is performed 7409. Of course, if the recovery of the communication with the satellite 2 is known in advance, the present invention is not limited to this, and the recovery with the satellite 2 may be waited.

Next, with reference to FIG. 20, a second example of the sequence during the satellite switching post-processing period is shown. This sequence is shown in Figure 1.
4 corresponds to the flow reaching 6705. This case is 7507 when Bs2 (beam via satellite 2) is detected after the satellite switching section 7504 and it is the same frequency as the used frequency in Bs1. In this case, communication can be continued using Bs2 of satellite 2 without additional steps 7509. In the post-control slot, a confirmation message of success in switching may be transmitted 7508 using Bs1 as necessary.

Next, referring to FIG. 21, a third example of the sequence during the satellite switching post-processing period is shown. This sequence is shown in Figure 1.
4 corresponds to the flow reaching 6709. In this case, Bs2 (satellite 2
This is a case where the beam (passing beam) is detected, but the beam is not the beam of the frequency assigned to the own station 7607. Therefore,
It is necessary to request 7608 a new frequency to be used after the satellite switching period. At this time, a frequency acquisition request is issued in the post-control slot 7605, which is Bs which is a beam from the satellite 1.
1 is used. As a result, if the request is denied 76
09, the disconnection process 7610 is explicitly performed again using Bs1 in the post-control slot. The merits of the explicit disconnection processing are as described above. After disconnection, the processing is terminated or switched to another communication means 7611. The frequency acquisition request and the disconnection process based on the rejection result thereof in the post-control slot may be performed in the same post-control slot or in different post-control slots. If the same post-control slot is used, the duration of the post-control slot is 2RTT.
(Round Trip Time) + α or more. When making a new connection request using Bs2, the request may be sent directly to the satellite 2 other than the post-control slot section. In this case, since there is a loss due to a collision with a competing call, the utilization efficiency of the line is low. On the other hand, in Bs1 using the post-control slot, the already established connection (the connection used before the satellite switching period) can be used, so that there is no competition and the efficiency is high.

Next, with reference to FIG. 22, a fourth example of the sequence during the satellite switching post-processing period is shown. This sequence is shown in Figure 1.
4 corresponds to the flow to 6710. In this example, Bs2 detected 7704 after the satellite switching period.
Is not assigned to the own station, 7707, B
This is the case where the request for the frequency to be used in s2 is made 7708, and the request is accepted. In this case, after the end of the post-control slot 7705, communication can be continued using Bs2 7710.

In the above embodiment, the processing of the satellite switching pre-processing period and the control of the satellite switching post-processing period have been described, but these controls may be performed only in the pre-processing period. Similarly, only the processing in the post-processing period may be performed.

The number of front control slots and the number of rear control slots are not necessarily one. However, the time position of the previous control slot is set not to immediately before the satellite switching period but to a position where some control is possible after the end of the previous control slot. Similarly, the temporal position of the post-control slot is set not after the satellite switching period but after the switching, but after a grace period such that the radio wave state of the satellite 2 can be confirmed.

A guard time is inserted between the front / rear control slot and the normal slot in consideration of satellite switching time, propagation time difference, and receiver synchronization time.

The rear control slot has a longer length and a larger number as compared with the front control slot. This is because in the post-control slot, control such as disconnection processing is performed. On the other hand, the main purpose of the front control slot is to obtain information such as whether Bs2 (beam by the satellite 2) can be received and its frequency.

The switching time may be changed for each irradiation beam spot.

The time length of the satellite switching pre-processing period and the satellite switching pre-processing period may be changed according to the latitude and longitude.

(6) Example of Device Configuration for Realizing Satellite Switching System (6-1) Terminal Side Configuration FIG. 23 shows an example of a terminal side device configuration for implementing the operations of the above-described embodiments. 3501 is an antenna, 3502
Indicates a modem, and all parts below the modem operate by exchanging digital data. The synchronization signal extraction means 3503 extracts timing such as frame synchronization from the received signal. The satellite switching control information extraction unit 3504 provides a function of extracting information regarding satellite switching from the received signal. The information on satellite switching is information on points at which the data type is changed, such as inverted triangles 1 to 7 in FIG. 55, and breakpoints at which satellites are switched. These pieces of information are present in a part of the control information section in the downlink from the satellite, and are provided from the base station side to the terminal side periodically or irregularly. Details of the satellite switching control information will be described later.

Reference numeral 3505 is a reception buffer. this is,
It is used, for example, in the case where streaming-type data having a constant data amount per time such as broadcasting is supplied from a terminal. Since the throughput per hour is predetermined for the streaming data, it is classified as short response time data in the classification of FIG. In the present invention, since data is transmitted intermittently from the base station side for each data segment, it may be necessary to shape the data into a certain amount of data per original time during reproduction on the terminal side or transfer to another device. is there. This buffer is used for smoothing this throughput. Therefore, the amount is determined in consideration of the assumed amount of data per unit time of the streaming system and the times of the short response time data 5507 and the long response time data 5508 described in FIG. Therefore, the size of this buffer is larger than the conventional receive buffer. 3506 User data is the content of data to be sent using this terminal. The controller at 3507 comprehensively controls the operation of the terminal. The transmission timing control means 3508 adjusts the timing of data transmission. For example, it is determined whether it is the time at which the own station is currently transmitting or whether the type of data to be transmitted is correct, and control is performed to transmit at an appropriate timing. The terminal information sending means of 3509 adds data that can identify the sender of the data for each authentication or terminal to the sending data. The transmission data type switching means 3510 switches the type of data that the local station can currently transmit. Specifically, the type of data to be downloaded is switched depending on whether the currently transmittable data is the short response time data or the long response time data. 3511/3514 are buffers for long / short response time data, and 3512/331, respectively.
3 is long / short response time data, respectively.

(6-2) Base Station Side Configuration FIG. 24 shows an example of the base station side apparatus configuration for realizing the operation of the above-described embodiment. This base station is responsible for transmitting and receiving satellite communication data, and it is assumed that the satellite attitude control and other operations are performed by another station.

3601 is an antenna, and at least two antennas of the satellite 1 before switching and the satellite 2 after switching are used. The number of antennas depends on the satellite configuration. This configuration assumes a case where one of the three satellites is always used except when switching.

A receiving device 3602 demodulates the received signal from the terminal and digitizes it. 3603 terminal information extraction means,
Authentication at the start of connection with the terminal and extraction of information for determining whether the data is from the correct terminal are performed. 3604
Is a receive buffer. A terminal management unit 3605 manages the currently used frequency band (channel) in addition to terminal authentication and billing. Reference numeral 3606 is the received user data. These are distributed to the users by being classified by the users to be used by the 3618 frequency band selecting / allocating means. The work to be divided for each user is, specifically, 36
Reference numeral 05 denotes an operation of converting the unique address of the satellite section to an address of the outside world based on the information from the terminal management means, and sending with a different destination for each user. The external address may be, for example, an Ip address on the Internet. The satellite selecting means 3607 is a switch matrix that switches between the transmitting device, the receiving device, and the antenna to be used. The switch is controlled by the satellite selection control means at 3608. Reference numeral 3609 is a sending device. Since it is in front of the satellite selecting means 3607, the output from here may be an intermediate frequency (IF). The 3610 transmission timing control means performs transmission in accordance with the switching timing, such as the inverted triangles 1 to 7 in FIG. 3611
The switching control flag injecting means injects satellite switching control information used on the terminal side. The 3612 transmission data type switching means switches between 3615 short response time data and 3616 long response time data. 3613/3614
Are buffers for short / long response time data respectively. These devices are multiplexed for each frequency band (or each transponder), and 3617 and 3619 are user data in the transmission direction. The frequency band to be used is determined by the 3618 frequency band selecting / allocating means.
The data from the terminal management means 605 is referenced to perform the distribution. 3620 holds the satellite number currently in use.
The 3621 sending controller integrally controls the sending of each transponder. The 3622 scheduler holds schedule data such as satellite switching time and switching control method. The 3623 satellite control information management means holds satellite operation information related to data transmission and reception based on the information from the 3625 satellite control means that manages the operation of the satellite. The 3624 clock provides a time reference for synchronizing the operation of the entire base station system.

(6-3) Example of switching control information An example of satellite switching control information is shown in FIG. 3701 is the individual identification number of the current satellite. 3702 is an event type indicating the type of the next break point. 3703 is a countdown value until the next breakpoint is reached. The event types are the data type delimiter, the satellite switching delimiter in FIG. 3, the satellite switching period inrush point and the escape point in FIG. 5, the satellite switching pre-processing period intrusion point, and the satellite switching post-processing period in FIG. In order to show the meaning of the event before the data type or control method switching event occurs, such as the rush point, the front control slot start point, the rear control slot start point, and the adjustment slot insertion point due to the variation of the satellite orbital elements. To use. The countdown value is
It indicates the time remaining until the event occurs and the number of frames, and is used for the purpose of enabling the terminal side to schedule preparations for the switching point in advance. If the countdown value is counted by the number of frames, for example, the terminal side does not need to have an accurate clock. On the contrary, if the clocks of the terminal side and the base station side are set correctly, the time may be counted down. If the countdown data has an 8-bit unsigned structure, it continues to indicate 255 (decimal) if the time is sufficiently far before the event occurs. Event occurrence time is 254 frames (or seconds, milliseconds, etc.)
When the following is reached, the countdown value is 254,25
It will be reduced to 3. When the countdown reaches 0,
Switch over. By indicating the countdown, the countdown value used for notifying the switching time is not limited to 8 bits even for terminals that have joined during the countdown,
Other bits may be used. In addition, if it is marked, the time elapsed from the occurrence of the past event may be shown if it is sufficiently far to the occurrence of the next event and there is no problem in notifying the next event. Showing past events helps the terminal connected immediately after the event elapses to quickly grasp the current line status, which can contribute to efficient scheduling of terminals. In addition, the satellite switching control information is not limited to one, but the event type and the countdown value (positive and negative values including elapsed events) regarding a plurality of past and future switchings.
You may present more than one. In this case, for example, since information about how many times the front control slot and the rear control slot in FIG. 11 will come will be obtained, scheduling on the terminal side can be performed more efficiently. The satellite number of 3701 can be used for providing information such as the position of the satellite to the terminal, but is not essential.

(7) Example of Service An example of service when the present invention is applied to satellite communication / satellite broadcasting using satellites will be shown.

(7-1) Push-Type Broadcasting Service FIG. 26 is a functional block diagram of a terminal installed in a mobile station such as an automobile to receive this service.

Local information of all over Japan is broadcast from the satellite. This area information includes information about local spring water points, public hot spring resorts, tourist spots unique to the area, delicious shops, secret hot springs, historical spots, and local folk tales, local history, local music, etc. .. It also includes traffic information such as traffic jams around Japan, traffic regulation information, and weather information. These pieces of information are received via the antenna 5101 and the tuner unit 5102, and are transmitted to the decoder unit 5
The data is demodulated by 103 into a form such as a still image / moving image, voice, and character data.

In the terminal, the US NAVSTAR satellite,
Russian GLONASS satellite and European GALIL
A position information processing unit 5105 that can measure and determine its own position using an EO satellite or the like is included. It may use a mobile phone or a handheld mobile phone (PHS) to determine its position. In any case, the position information processing unit 5105 also includes an antenna unit and the like necessary for position measurement / determination. The position information processing unit 5105 outputs its own position information to the navigation central processing unit 5106 for performing so-called car navigation. At the same time, the position information processing unit 5105 outputs its own position information to the information filter unit 5104. Information filter unit 5104
Information of the set navigation route and the destination, which is output from the navigation central processing unit 5106, is also input to the.

The still image / moving picture, voice, character data, etc. demodulated by the decoder unit 5103 are their own position information input from the position information processing unit 5105 and the planned car navigation route input from the navigation central processing unit 5106. Based on the destination information, the information filter unit 5104 selects. Navigation central processing unit 5106 in advance
In addition, if the type and content of the information desired to be reproduced are registered, selection based on the registered content is possible. The selected still images / moving images, voices, character data, etc. are superimposed on the car navigation image and the guide voice by the navigation central processing unit 5106, and the superimposed images / videos are displayed on the display unit 5107 and are superimposed. The generated voice is output from the speaker 5109 via the voice output unit 5108. The audio output unit may use a car stereo. Further, the selected still image / moving image, voice, character data, etc. may not be superimposed on the car navigation image or voice.

Map information necessary for navigation, building
Three-dimensional information such as pedestrian bridges, overpasses and tunnels, parking lots,
Drive information of a restaurant or the like is recorded in the memory unit 5113, and is appropriately called by the navigation central processing unit 5106 to be used for image / video display and audio output. The information recorded in the memory unit 5113 will be described with reference to FIG. The information may be updated based on the change / addition information at any time in the stage, or may be requested to the communication center station 5007 to change / add using a mobile phone or the like, and transmitted by broadcasting or communication via the satellite 5001. The requested change / additional information may be changed / additionally updated when the terminal receives it. Although an example of a non-geostationary satellite is shown in FIG. 2, a geostationary satellite may be used here.

As described above, it is possible to automatically reproduce the information around the position of the vehicle being driven, the information near the route of the drive, and the information around the destination.

The protocol according to the present invention includes a control unit 5114.
Is built into. The signal transmitted from the satellite includes the satellite orbit information, and the satellite orbit data demodulated by the decoder unit 5103 is input to the satellite orbit information processing unit 5105. At the same time, the position information of the own vehicle is input from the position information processing unit 5105 to the satellite orbit information processing unit 5105. From these pieces of information, the satellite orbit information processing unit 5105 obtains the elevation angle and azimuth angle at which the satellite in operation at that time is located on the celestial sphere, and outputs it to the control unit 5114. Control unit 51
At 14, information about the elevation angle and azimuth angle of the input satellite,
Comparing the traveling direction information output from the navigation central processing unit 5106 with the three-dimensional information such as the building, pedestrian bridge, overpass, and tunnel around the vehicle built in the memory unit 5113, the communication / broadcast is interrupted. The tuner unit 5102 and the decoder unit 5103 at a place / time that is likely to be
Are controlled according to the present invention. The information on the traveling direction of the vehicle may be output from the position information processing unit 5105 to the control unit 5114.

The car navigation system, the display unit and the voice output unit may be controlled by voice. That is, the microphone 511
The voice input via 0 is recognized / decoded by the voice recognition unit 5111, a control signal is sent to the navigation central processing unit 5106, the display unit 5107, and the voice output unit 5108, and each is controlled. In FIG. 26, the flow of control signals is indicated by a dotted line.

(7-2) Pull-type broadcasting / communication service FIG. 27 is a functional block diagram of a terminal installed in a mobile station such as an automobile to receive this service.

This service requests required information during driving or in advance of driving, and receives required information transmitted via the satellite on the terminal side. It will be described together with FIG. Although an example of a non-geostationary satellite is shown in FIG. 2, a geostationary satellite may be used here.

For example, while driving, when it is desired to watch a travel program or information program that has been a feature of the area in which the vehicle is running,
The required information is sent to the communication center station 50 via the transmitter 5214.
Claim 07. The transmitting unit 5214 may be capable of communicating via the satellite 5001, or may be a mobile phone or a simplified mobile phone. When the transmitting unit 5214 can communicate via the satellite 5001, the transmitting antenna 52
15 may be shared with the receiving antenna 5201. The transmitting unit 5214 has a position information processing unit 5205, which has a position measuring / determining function of itself, similar to the position information processing unit 5105 shown in (6-1). Input via 5206. In addition, the navigation central processing unit 5206 inputs information about the planned route and destination by the navigation of the own vehicle to the transmission unit 5214. That is, the transmission unit 5214 transmits information including the position information of the own vehicle, the planned route, the destination, and the travel program / information program desired to be watched or heard to the communication center station 5007.

The communication center station 5007 transmits the requested travel program and information program via the satellite 5001. On the terminal side, the above programs are received via the antenna 5201 and the tuner unit 5202, and these programs are received by the decoder unit 52.
By 03, it is demodulated into a form such as a still image / moving image, voice, and character data.

The demodulated still image / moving image, voice, character data, etc. are superimposed on the car navigation image and guide voice by the navigation central processing unit 5206, and the superimposed image / video is displayed on the display unit 5207.
The superimposed voice is output from the speaker 5209 via the voice output unit 5208. The audio output unit may use a car stereo. Further, the selected still image / moving image, voice, character data, etc. may not be superimposed on the car navigation image or voice.

If the demodulated still image / moving image, voice, character data, etc., which is convenient to be reproduced when the own vehicle approaches the place as the information about the area, is temporarily stored in the memory unit 5213. It is also possible to accumulate. For example, it can be solved by providing a function of displaying / sound output when a spot / store that meets the conditions approaches. Of course, the information request regarding the spot or the store is made in advance to the communication center station 5207 by the same method,
It is necessary to receive and store it on the terminal side. Based on the own vehicle position information from the position information processing unit 5205, the navigation central processing unit 5206 appropriately reads out necessary information from the memory unit 5213, and the navigation central processing unit 5206
The car navigation image and the guide voice are superposed on each other, the superposed image / video is displayed on the display unit 5207, and the superposed voice is output to the speaker 5 via the voice output unit 5208.
It outputs from 209. The audio output unit may use a car stereo. Further, the selected still image / moving image, voice, character data, etc. may not be superimposed on the car navigation image or voice.

If the navigation central processing unit 5206 has a built-in Internet browser function, information can be retrieved by connecting to the Internet via a mobile phone. When you want to get information around the road while driving, for example what kind of place it is, what kind of talk there is, what kind of menu there is, congestion situation, what event is today, etc. , It is convenient to use this service.

The protocol according to the present invention includes a control unit 5217.
Is built into. The signal transmitted from the satellite includes the satellite orbit information, and the satellite orbit data demodulated by the decoder unit 5203 is input to the satellite orbit information processing unit 5216. At the same time, the position information of the own vehicle is input from the position information processing unit 5205 to the satellite orbit information processing unit 5216. This position information processing unit 5205 has the same function / device configuration as the position information processing unit 5105 shown in (6-1). From these information, the satellite orbit information processing unit 521
In 6, the elevation angle and the azimuth angle at which the satellite in operation at that time is located on the celestial sphere are obtained and output to the control unit 5217. In the control unit 5217, the information of the elevation angle and the azimuth angle of the input satellite, the information of the traveling direction output from the navigation central processing unit 5206, and the buildings, pedestrian bridges, and overpasses around the vehicle built in the memory unit 5213.・ Comparing with 3D information such as tunnels, places where communication / broadcasting may be cut off ・
At time, tuner section 5202 and decoder section 520
3 and the transmitter 5214 are controlled according to the present invention. The information regarding the traveling direction of the own vehicle may be output from the position information processing unit 5205 to the control unit 5217.

The car navigation system, the display unit and the voice output unit may be controlled by voice. That is, the microphone 521
The voice input via 0 is recognized and decoded by the voice recognition unit 5211, a control signal is sent to the navigation central processing unit 5206, the display unit 5207, and the voice output unit 5208, and each is controlled. In FIG. 27, the flow of control signals is indicated by a dotted line.

(7-3) Satellite Broadcasting FIG. 28 is a functional block diagram of a terminal installed in a mobile station such as an automobile to receive this service.

Description will be given in conjunction with FIG. Although an example of a non-geostationary satellite is shown in FIG. 2, a geostationary satellite may be used here. The signal broadcast from the broadcasting station 5007 via the satellite 5001 includes data information such as audio information, moving image information, and characters.

On the terminal side, the above-mentioned programs are received via the antenna 5301 and the tuner unit 5302, and these programs are demodulated by the decoder unit 5303 into still image / moving image, voice, character data and the like.

The demodulated still image / moving image is displayed on the display unit 5.
The data is displayed on the display unit 5304, and the character data and the like are superimposed on the still image / moving image. The voice is output from the speaker via the voice output unit 5305. The display unit 5304 may be a vehicle-mounted television receiver, and the audio output unit may be a car stereo.

The protocol is built in the control unit 5310. The signal transmitted from the satellite includes satellite orbit information, and the satellite orbit data demodulated by the decoder unit 5303 is input to the satellite orbit information processing unit 5311. At the same time, the position information and traveling direction information of the own vehicle are input from the position information processing unit 5312 to the satellite orbit information processing unit 5216. This position information processing unit has the same function / device configuration as the position information processing unit 5105 shown in (6-1). From the position information of the own vehicle and the satellite orbit information, the satellite orbit information processing unit 5311 obtains the elevation angle and azimuth angle at which the satellite in operation at that time is located on the celestial sphere, and outputs it to the control unit 5310.
In the control unit 5310, the information about the elevation angle and the azimuth angle of the input satellite, the information about the traveling direction output from the position information processing unit 5312, and the building / pedestrian bridge / overpass around the vehicle built in the memory unit 5309. Comparing with three-dimensional information such as a tunnel, the tuner unit 5302 and the decoder unit 5303 are controlled according to the present invention at a place / time where broadcasting is likely to be interrupted.

The display unit and the voice output unit may be controlled by voice. That is, the voice input through the microphone 5307 is recognized and decoded by the voice recognition unit 5308, a control signal is sent to the display unit 5304 and the voice output unit 5305, and each is controlled. In FIG. 28,
The flow of control signals is indicated by the dotted line.

(8) Embodiment for Switching Between Beams FIG. 29 shows a satellite broadcast transmission / reception system including a center station 8101, a communication satellite 8102, and a mobile unit 8103. The satellite 8102 may be a broadcast satellite, and a geostationary satellite,
It may be a non-geostationary satellite. In the embodiments of the present invention described below, non-geostationary satellites, particularly, an embodiment assuming a long elliptical orbit hygiene will be described.

The center station 8101 has a transmitter 8104, which is an antenna 810 for communicating with the satellite.
5, a communication device 8106 for communicating with the satellite, a coverage area database 8108 in which data on beam spots emitted from the satellite to the ground are accumulated, and a content database 8109 in which contents to be distributed using the communication satellite are accumulated. , A function of selecting the contents of the coverage area database 8108 and the contents database 8109 to create data to be transmitted to the communication satellite, and reading the data transmitted from the receiving terminal, and determining the data to be transmitted to the communication satellite based on the data. Control device 810 having either or both of the functions
It consists of 7.

On the other hand, the receiving terminal 82 is provided in the mobile unit 8103.
01, which is a positioning antenna 8203 for positioning a moving object, a communication antenna 8202 for communicating with a satellite, and positioning and moving of the current position based on data received by the positioning antenna. Positioning device 8205 for calculating speed and moving direction, communication device 8204 for transmitting / receiving data to / from satellite 8102, display device by selecting necessary data from data received by communication antenna and data received by positioning device A function of transmitting the necessary data to the center station, a function of transmitting the positioning information of the mobile body to the center station when necessary, from the data received by the communication device and the data received by the positioning device. Than,
When a user using the receiving terminal inputs data that needs to be received, the control device 8206 has a function of transmitting the data to the center station when the data is needed. Note that as the antennas 8202 and 8203, it is of course possible to use an antenna in which a communication antenna and a positioning antenna are integrated. Positioning device 82 here
Reference numeral 05 may be a positioning device using a positioning satellite called GPS (Grobal Positioning System), a positioning device using another positioning satellite, or a positioning device using a mobile phone.

Next, the respective devices of the center station and the receiving terminal will be described. Coverage area database 810
As shown in FIG. 30, when one satellite distributes information to all over Japan, as shown in FIG. 30, a device mounted on the satellite emits a beam to perform communication in the range indicated by 8251. One circle indicated by 8251 is a coverage area. Generally, in satellite communication using a low frequency band, the number of beams required to cover the whole of Japan is small, but as the frequency increases, the irradiation range of one beam narrows, so as shown in FIG. A lot of beams are needed. The coverage database 8108 is a database for grasping the irradiation position of this beam at the center station. Figure 3 shows the contents of the coverage database
Shown in 1. The beam data is a beam number 8801 given arbitrarily, a beam name 8802 given the name of a representative area for recognizing the beam, and a center latitude 880 of the beam.
3, a table consisting of respective data of beam center longitude 8804 and beam radius 8805.

Next, the relationship between the data in the coverage area and the moving body, which is the central idea of the present invention, will be described with reference to FIG. In satellite communication, as shown in FIG. 30, uniform circular broadcasting is performed nationwide by using a plurality of circular beams. On the other hand, when performing satellite communication using non-geostationary satellites, there is a problem that the beam position shown above does not always coincide with the preset beam position. This is because the non-geostationary satellite always controls the attitude of the satellite, and the satellite body is shaking.
For this reason, the irradiation position of the original beam is several tens of k
An error of about m in beam irradiation position occurs during attitude control. Therefore, as an example of the deviation of the beam irradiation position,
Considering the case where the radius of the beam becomes small in FIG. 32, the standard beam patterns 8308, 8 shown by thick lines are shown.
In the case of 306, since the beams overlap with each other when crossing the beams, the handover between the beams can be smoothly performed, and the deterioration of the communication quality represented by the communication interruption is not so problematic. Conceivable. However, in the case of a non-geostationary satellite, as described above, when the satellites fluctuate due to attitude control, and when beam patterns 8307 and 8305 shown by thin lines are formed, the overlapping portions of the respective beams are overlapped. As a result, there is a high possibility that communication quality will be degraded, which is represented by communication interruption. Therefore, in the present invention, the beam area is divided into three types as shown in FIG. These meanings are defined as a green signal area where there is almost no problem in communication quality when the moving object exists within the cone of 8405 and 8403 indicated by the dotted line, and the cone of 8406 and 8402 indicated by the thin solid line is defined. When a moving object exists within the cone indicated by the dotted line, the yellow signal area is defined as the area in which the communication quality may deteriorate, and is indicated by the thick solid line 84.
When a moving body exists between the cone of 04,8401 and the cone of the thin solid line described above, it is defined as a red signal area in which the deterioration of communication quality is remarkable. In addition, these red traffic lights,
The yellow and green signal areas are classified based on the attitude control error range shown in the catalog value of each satellite. For example, if the beam radius is N and the attitude control error of a satellite is M, the red signal area has a beam radius between N and NM, and the yellow signal area has a beam radius N-M.
From M to N-2M, the green signal area is N-2M or less.

In the present invention, the communication quality of the communication quality can be improved by transmitting to the center station prediction data indicating which area defined in the description of FIG. When the deterioration occurs, the center station is requested to change the communication quality to maintain the communication quality. This definition of communication quality is embedded in the data transmitted from the center station. An example of data transmitted from the center station will be described with reference to FIG. Reference numeral 8500 in FIG. 34 is the content data itself (original data). When this is transmitted to the satellite via the communication device, protocol conversion is performed, for example, O
It is converted to a data format according to the SI hierarchy and communicates with the satellite. In FIG. 34, the original data is A layer, B
When protocol conversion is performed in layers, headers 8501 and 8502 of each layer are added to the beginning of the data,
Alternatively, depending on the time, if the data length becomes unfamiliar, it is 850.
As shown in 3, the data of the original layer is divided and a header corresponding to the protocol of a certain layer is added. By embedding in the header of the layer protocol that requires data priority and quality compensation when performing protocol conversion for each layer, and performing bandwidth control or priority control in the layer that refers to it, the receiving terminal Realize services according to the request from.

FIG. 35 shows TOS (Type Of S) embedded in the above-mentioned protocol when priority control and quality compensation are required.
ervice). Since this is an example, it is of course possible to add other service concepts. For example, the example of FIG. 35 shows the contents of header information in a certain protocol layer. In this example, version information 86
01, header length information 8602, TOS information 8603, and total data length 8604. The TOS information further includes priority information 8605, TOS information 8606, and stuff bit 8
It consists of 607. This stuff bit is priority information, T
It is not necessary because it is reserved in case the OS information is extended.

Reference numeral 8608 is an example of TOS information. In this example, the delay is minimized, the throughput is maximized,
This is an example of defining a normal service that maximizes reliability and minimizes charges. Of course, other services may be defined. The correspondence between the binary value and the characteristic is not limited to that shown in this embodiment.

The original data 8500 shown in FIG. 34 is data data in which content data and beam data are alternately superimposed as shown in 8701 to 8704 as shown in FIG. The content data here is
It is content data for broadcast communication represented by video data, music data, simple video data, and character data. Further, these include offline contents stored in media represented by magnetic tapes and contents delivered in real time represented by news programs and live broadcasts.

Next, the receiving terminal 8201 will be described.
FIG. 37 is a diagram showing an operation between the communication device, the control device, and the positioning device in the receiving terminal. First, after turning on the power of the receiving terminal, the content data, the beam data and the positioning information sent from the center station from the communication device and the positioning device, the direction in which the moving body is moving, and the speed thereof are processed in processing 8901 and processing 8902. It is acquired by the control device.
Since the beam data transmitted from the center station normally contains information on all areas subject to satellite communication, the control device filters only the beam data in the surrounding area based on the data received from the positioning device. Thereafter, the content data is retrieved by the control device (process 8903), and the retrieved content data is transmitted to the display device (process 890).
4) The beam data is extracted (process 8905). In the processing in the control device, it is assumed that the data is input to the control device in the "original data" state shown in FIG.
Next, in process 8906, the position of the mobile terminal after a few minutes and the necessity of changing the TOS are calculated. Regarding this content, a prediction method and a TOS changing method will be described with reference to FIG.

In FIG. 38, 9001 and 9004 indicate the outer boundary of the red signal area, 9002 and 9005 indicate the outer boundary of the yellow signal area, 9003 and 9006 indicate the outer boundary of the green signal area, and 9007 indicates the moving object at the present time. Position, 9008
Indicates a circle indicating the range where the moving body exists after a few minutes, and 9009 indicates a point where the probability that the moving body exists after a few minutes (N minutes) is the highest. The point 9009 is obtained by multiplying the direction vector obtained from the current position and direction by time. Further, the range 9008 has a radius M based on the point of 9009.
The range is (m). Although various values of M can be set here, it is assumed here that it is about an error that occurs during the attitude control described above. Of course, it is possible to give other values in advance, and it is also possible to dynamically determine in consideration of the traffic jam information obtained from the road traffic information, especially when the moving body is a car.

Next, a method of determining the TOS level from the predicted value of the position where the moving body exists shown in FIG. 38 will be described. The first method example is a method of simply calculating the area of the area including 9009 and taking the center of gravity thereof. In particular,
Red signal area is defined as 1 point, yellow signal area is defined as 2 points, green signal area is defined as 3 points, and the area of the circle of 9009 is normalized to 1
Then, 1 x Σ (area of red signal area) + 2 x Σ (area of yellow signal area) + 3 x Σ (area of blue signal area) is obtained, and if the value is 1 to 2, the communication quality is deteriorated. Since there is a high possibility, select the TOS that maximizes reliability,
T between 2 and 3 maximizes throughput
Select OS.

The second method example is a method in which the signal level of the beam is regarded as a fuzzy set having a membership function of an analog value, and the level of TOS is determined using the fuzzy inference shown in FIG. When the normalized value of the beam intensity is plotted on the vertical axis (membership function) and the distance is plotted on the horizontal axis, the radio field intensities of the respective beams are shown as 9101 and 9102. Note that 9101 corresponds to the signal levels 9001 to 9003 in FIG. 38, and 9102 represents 9 in FIG.
This corresponds to a signal level of 004 to 9006. Also, 9
Reference numeral 103 corresponds to the predicted radius circle of the moving body 9009 in FIG. The reasoning method is commonly used fuzzy reasoning (Reference: Michio Kanno, Fuzzy Control, Nikkan Kogyo Shimbun,
1988), 9101 and 9102 are regarded as rules, and the matching degree with the predicted position of the moving body is calculated.
It is assumed that the membership function 9104 is inferred by the Min inference method. After that, the center of gravity of the membership function of 9104 is calculated. If the calculation result is in the red signal area, the communication quality is likely to deteriorate, so the TOS that maximizes reliability is selected and the calculation result is yellow. If it is in the signal area, select the TOS that maximizes the throughput.
When the calculation result is in the green light area, normal TOS is selected. Note that although the membership function is given as a fixed value in this example, the output of the output increases during rainfall, especially when high frequency radio waves are used. It is also possible to correct the membership function according to the state or the ion density of the ionosphere. In the second method example, it is possible to respond to more detailed radio wave conditions as compared with the first method example.

By using such a method, the necessity of changing the TOS is calculated in 8906 to 8907 of FIG.
If the TOS needs to be changed, T is set in processing 8908.
Set the OS change command in the transmission data, then 890
At 9, the communication device transmits data to the center station. The format of the transmission data at that time is shown in FIG. The data to be transmitted to the center station in FIG. 40 includes the ID number 9201 of the mobile terminal and the latitude / longitude 9 of the current position of the mobile terminal.
202, 9203, requested TOS value 9204, and reserve area 9205. The ID number here is, for example, the IP address assigned to the mobile terminal,
Alternatively, the Media Access Con provided to the mobile terminal
trol address is possible.

Next, the input device of the receiving terminal will be described. The input device is a device for selecting a plurality of programs transmitted from satellites and performing initial setting. Figure 41
Is an example of a program selection interface of the receiving device.
Assuming a program, here a music program, 93
Numerals 01 to 9304 indicate the genre of music, 9305 indicates the contents of the specific music program program, 930
6 to 9307 are operation buttons for selecting a program, and 9310 is an enter button. In this example, the genre selection is expressed in the tab format, but the button format is also acceptable.

FIG. 42 shows a display example of the output device. 940
1 is an output screen, 9402 is a received content (video) display screen, 9403 and 9404 are data broadcast display screens, and 94.
Reference numeral 05 is a reception quality display screen. Also, 9406 to 9
Reference numeral 408 denotes an operation button. 9402 to 940
The display screens up to 5 can be switched by operating the display buttons. An example of the reception quality display screen is shown in FIG. In this example, the information on the location of the terminal, the reception level, and the quality when transmitting from the center station is displayed. These pieces of information can be selected by operating any of the all-function operation buttons.

In the present embodiment, in communication using a satellite, data such as broadcasting and streaming data that needs to be guaranteed with a constant throughput per hour, and traffic information, various telemetry information, and other temporal data are used. There is data that is loosely requested and may be missed at times. In the portion related to the satellite switching method of the present invention, the data transfer with a low time requirement is scheduled during the satellite switching period to keep the transfer rate of the data with a severe time requirement constant.

Regarding the beam stability, the present invention predicts the terminal position after several minutes when the terminal mounted on the moving body passes through the beam irradiation range, and based on the prediction result,
By predicting the radio wave condition of the area where the terminal is present, based on the prediction result, the terminal transmits a request for improvement of communication quality to the center station, and the center station performs communication according to the requested communication quality, It prevents the deterioration of communication quality in the overlapping area at the beam boundary due to the attitude control of non-geostationary satellites.

Further, in a satellite system such as a quasi-zenith satellite in which low-frequency satellite switching occurs, it is possible to smoothly perform processing when switching satellites without lowering communication efficiency when not switching. Smooth satellite switching is suitable for quasi-zenith satellite systems that handle many connections with a small number of satellites.

Further, according to the satellite communication system of the present invention, it is predicted in advance that the mobile terminal will enter the boundary of the beam irradiation of the satellite and the communication quality will be deteriorated. It is possible to ensure stable communication quality on the receiving terminal side by notifying the center station of a request for improvement or maintenance of communication quality and transmitting data to the receiving terminal with the communication quality according to the request. Become.

[0098]

As described above, according to the present invention,
It is possible to improve efficiency or quality of communication or broadcasting.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a trajectory.

FIG. 2 is a diagram showing an example of a service form.

FIG. 3 is a timing chart diagram for allocating transmission / reception of data with a slow response time request when switching satellites.

FIG. 4 is a flowchart showing an operation on the terminal side.

FIG. 5 is a timing chart of an embodiment in which beams are emitted from a plurality of satellites at different frequencies in the same area when switching satellites.

FIG. 6 is a diagram showing an example of a timing chart beam pattern of an embodiment in which beams are emitted from a plurality of satellites at different frequencies in the same area when switching satellites.

FIG. 7 is an operation sequence diagram when the beam of the satellite 2 can be supplemented during the satellite switching period.

FIG. 8 is an operation sequence diagram when the beam of the satellite 2 cannot be captured during the satellite switching period.

FIG. 9 is a diagram showing a second example of an operation sequence in the case where the beam of the satellite 2 can be supplemented during the satellite switching period.

FIG. 10 is a flowchart showing an operation on the terminal side.

FIG. 11 is a timing chart diagram of an embodiment in which handover is gradually performed in a time division manner.

FIG. 12 is a beam spot diagram of an embodiment in which handover is gradually performed in a time division manner.

FIG. 13 is a flowchart of a satellite switching pre-processing period.

FIG. 14 is a flowchart of a processing period after satellite switching.

FIG. 15 is a first example of an operation sequence of satellite switching preprocessing.
Illustration.

FIG. 16 is an example 2 of an operation sequence of satellite switching preprocessing.
Illustration.

FIG. 17 is an example 3 of an operation sequence of satellite switching preprocessing.
Illustration.

FIG. 18 is an example 4 of an operation sequence of satellite switching preprocessing.
Illustration.

FIG. 19 is a first example of an operation sequence of satellite switching post-processing.
Illustration.

FIG. 20 is an example 2 of an operation sequence of satellite switching post-processing.
Illustration.

FIG. 21 is an example 3 of an operation sequence of post-satellite switching processing.
Illustration.

FIG. 22 is an example 4 of an operation sequence of satellite switching post-processing.
Illustration.

FIG. 23 is a diagram showing a configuration on the terminal side.

FIG. 24 is a device configuration diagram on the base station side.

FIG. 25 is a diagram showing an example of satellite switching information format.

FIG. 26 is a functional block diagram of a terminal installed in a mobile station such as an automobile to receive a push-type broadcast service.

FIG. 27 is a functional block diagram of a terminal installed in a mobile station such as an automobile to receive a pull-type broadcast service.

FIG. 28 is a functional block diagram of a terminal installed in a mobile station such as an automobile to receive satellite broadcasting.

FIG. 29 is a representative diagram showing a configuration of a satellite communication system and a method thereof according to the present invention.

FIG. 30 is a view showing a situation of irradiation of a plurality of beams.

FIG. 31 is a diagram showing an example of a beam data format.

FIG. 32 is a diagram showing an example of beam variation due to inter-beam handover and attitude control.

FIG. 33 is a diagram showing levels set for a beam.

FIG. 34 is a diagram showing packetization of data when passing through a protocol layer.

FIG. 35 is a diagram showing an example of TOS (Type Of Service).

FIG. 36 is a diagram showing an example of multiplexing content data and beam data.

FIG. 37 is an example showing an operation on the receiving terminal side.

FIG. 38 is a diagram showing estimation of a moving position of a terminal.

FIG. 39 is a diagram showing an example of a TOS determination method using a fuzzy set.

FIG. 40 is a diagram showing an example of a quality request format transmitted from the receiving terminal to the center station.

FIG. 41 is a diagram showing an example of an interface of an input device.

FIG. 42 is a diagram showing an example of an interface of an output device.

FIG. 43 is a diagram showing an example of a reception quality display screen.

FIG. 44 is a supplementary explanatory diagram of an example of a service form.

[Explanation of symbols]

3501 ... Antenna, 3502 ... Modem, 3503 ... Sync signal extraction means, 3504 ... Satellite switching control information extraction means, 3505 ... Buffer, 3506 ... User data (payload), 3507 ... Controller, 3508 ... Transmission timing control means, 3509 ... Terminal Information transmission means, 3
510 ... Sending data type switching means, 3511 ... Long response time data buffer, 3512 ... Long response time data, 3513 ... Short response time data, 3514 ... Short response time data buffer, 5001 ... Satellite, 5002 ... Satellite tracking, telemetry And command (TT & C) line, 50
03 ... satellite tracking control operation station, 5004 ... communication return link, 5005 ... broadcasting uplink, communication feederlink, large-capacity image communication uplink, 5006 ... bidirectional communication with mobiles, homes, etc., 5007 ... broadcasting Station, communication center station, 5008 ... Broadcast to mobiles, homes, etc., 500
9 ... Large-capacity image communication, 5010 ... Mobile stations such as automobiles, 5
011 ... Fixed station of general home, etc., 5012 ... Bidirectional communication with mobile / home via relay facility, broadcasting to mobile / home, large-capacity image communication, 5013 ... Relay facility, 50
14 ... Two-way communication with mobiles / homes via relay facilities, broadcasting to mobiles / homes, large-capacity image communication, 501
5 ... Two-way communication with mobile / home, etc. via relay equipment, broadcasting to mobile / home, large-capacity image communication, 580
1 ... satellite 1 spot 1 (used frequency f1), 5802 ...
Satellite 1 spot 2 (used frequency f2), 5803 ... Satellite 1 spot 3 (used frequency f1), 5804 ... Satellite 1 spot 4 (used frequency f2), 5805 ... Satellite 2 spot 1 (used frequency f1), 5806 ... Satellite 2 Spot 2
(Use frequency f2), 5807 ... Satellite 2 spot 3 (use frequency f1), 5808 ... Satellite 2 spot 4 (use frequency f2), 8401, 8404 ... Beam irradiation range defined as red signal area, 8402, 8405 ... Yellow signal Beam irradiation range defined as area, 8403, 8406 ... Beam irradiation range defined as green signal area, 8603 ... TOS information, 8
801 ... Beam number, 8802 ... Beam name, 8803
… Beam center latitude, 8804… Beam center longitude, 880
5 ... Beam radius, 9101 ... Normalized intensity of beam A, 9
102 ... Normalized intensity of beam B, 9103 ... Probability of predicted position, 9104 ... Inferred fuzzy membership function, 9401 ... Display screen, 9402 ... Image display area,
9403, 9404 ... Data display area, 9405 ... Quality display area, 9501 ... Display example of quality display area.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takaharu Ishida             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Hideki Inoue             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. F term (reference) 5K072 AA15 BB03 BB04 BB12 BB13                       BB14 BB22 DD02 DD03 DD04                       DD11 DD16 DD17 EE04 EE12                       GG11 GG15

Claims (60)

[Claims] 1. A signal for receiving a signal from an artificial satellite to be serviced in a predetermined service area by moving in a non-geostationary satellite orbit, the signal from a predetermined satellite among the artificial satellites being received, A receiving method of previously receiving, from the predetermined artificial satellite, information from when the signal of the predetermined artificial satellite is substantially not received until when the signal of the alternative artificial satellite is substantially received. 2. The receiving method according to claim 1, wherein a voice display or an image display is performed based on the previously received signal after the radio waves of the predetermined artificial satellite are substantially not received. 3. The information according to claim 1, wherein the information received from the artificial satellite includes one having relatively high temporal continuity and one having relatively low temporal continuity, and the previously received information is the high information. A receiving method that is a request signal. 4. A signal for receiving a signal from a predetermined satellite among the artificial satellites, which moves in a non-geostationary satellite orbit and is replaced by a predetermined service area. Then, a receiving method of receiving a signal from the alternative artificial satellite and performing processing for switching from reception from the predetermined artificial satellite to reception from the alternative artificial satellite based on the received signal. 5. The receiving method according to claim 4, wherein a signal from the substitute artificial satellite is received while receiving a signal from the predetermined artificial satellite. 6. The receiving method according to claim 5, wherein the process for receiving from the substitute artificial satellite is a line reservation of the substitute artificial satellite. 7. The receiving method according to claim 6, wherein the reservation of the line information includes a reservation of a frequency used for the alternative satellite. 8. The receiving method according to claim 4, wherein the reception of the signal of the predetermined artificial satellite and the reception of the signal of the alternative artificial satellite are temporally exclusive. 9. A receiving method according to claim 7, wherein when said reservation is rejected, a corresponding signal is obtained from an alternative means. 10. The receiving method according to claim 4, wherein it is judged whether or not the signal from said substitute artificial satellite and the signal from said predetermined artificial satellite have the same frequency, and the signal is received based on said judgment. 11. The reception method according to claim 10, wherein when the frequencies are the same, the reception is continued at the frequency. 12. The receiving method according to claim 4, wherein the switching process is a request for use of the substitute artificial satellite via the predetermined artificial satellite. 13. A non-geostationary satellite orbit is moved to receive a signal from an alternate serviced satellite in a predetermined service area, receive a signal from a predetermined satellite of the artificial satellites, and then perform the alternate operation. It is possible to substantially receive a signal from an artificial satellite, and after the reception from the alternative artificial satellite becomes possible, the predetermined information is added so as to compensate for the missing information in the received information from the alternative artificial satellite. A receiving method for receiving signals from artificial satellites. 14. A non-geostationary satellite orbit is traversed to receive a signal from an alternate serviced satellite in a predetermined service area, receive a signal from a predetermined satellite of the artificial satellites, and then perform the alternate operation. A signal that can be substantially received from an artificial satellite, and a signal indicating that reception switching has been performed to the predetermined artificial satellite after reception from the alternative artificial satellite is possible How to receive. 15. The transmission according to claim 14, which indicates that reception switching has been performed for the predetermined artificial satellite,
A receiving method performed after a signal from the alternative satellite is received. 16. A signal is received from an artificial satellite which is capable of servicing in a predetermined service area by moving in a non-geostationary satellite orbit, receiving a signal from a predetermined satellite among the artificial satellites, and then receiving the signal. A signal can be substantially received from the alternative satellite, and when the signal from the alternative satellite cannot be received, the signal from the alternative satellite is received via the predetermined artificial satellite. How to request to receive. 17. The receiving method according to claim 16, wherein the request is frequency allocation. 18. A non-geostationary satellite orbit is moved to receive a signal from an artificial satellite to be serviced instead of a predetermined service area, and a signal having a frequency corresponding to a geographical condition in the service area is received from the artificial satellite. The thing
Detecting the frequency to be received, based on the detection,
A receiving method for receiving a signal from the alternative artificial satellite. 19. A radio signal radiated to at least one of the radio signals radiated from an artificial satellite to cover different service areas,
A request signal for requesting to change the radio signal from the artificial satellite so as to judge the present situation in the reception of the radio signal or to estimate the future situation and to improve the reception state based on the judgment or the estimation. How to receive. 20. The receiving method according to claim 19, wherein the reception status of the radio wave signal is determined based on a prediction at the reception position. 21. The receiving method according to claim 19, wherein the reception status of the radio wave signal is determined based on beam area information. 22. The receiving method according to claim 21, wherein the beam area information is provided by the center station. 23. The receiving method according to claim 22, wherein the beam area information is information on latitude, longitude and beam spread. 24. The reception method according to claim 19, wherein the judgment of the reception status of the radio wave signal is an estimation of radio wave quality. 25. The receiving method according to claim 24, wherein the radio wave quality is obtained by filtering the obtained beam area. 26. The receiving method according to claim 19, wherein fuzzy inference is performed on the moving position and the beam spread, and the signal quality is estimated based on the fuzzy inference. 27. A radio signal radiated to at least one of the radio signals radiated from an artificial satellite to cover different service areas,
A receiving method of estimating a reception situation of a future radio signal and issuing a request signal for requesting by selecting one of improvement of throughput and reception situation based on the estimation. 28. Receiving a radio signal radiated to at least one of the radio signals radiated from an artificial satellite to cover different service areas,
A signal method for estimating a future reception condition of a radio wave signal and issuing a request regarding reception delay, throughput, reliability or a charge based on the estimation. 29. A non-geostationary satellite orbit is moved to receive a signal from an artificial satellite to be serviced instead of in a predetermined service area, and information of the predetermined satellite from a predetermined satellite among the artificial satellites and A receiving method of receiving a signal including information of the artificial satellite to be replaced, and performing processing for switching reception from the predetermined artificial satellite to the changing satellite based on the received information. 30. The receiving method according to claim 29, wherein a period from the received signal to a predetermined event or a period corresponding thereto is obtained, and the previous period switching process is performed based on the reception. 31. The receiving method according to claim 29, wherein the predetermined event is a time remaining until switching satellites or the number of frames. 32. Receiving a signal from an artificial satellite to be serviced by moving in a non-geostationary satellite orbit instead of in a predetermined service area, and performing arithmetic processing based on the received signal in the service area. A receiving method for calculating a reception state from the artificial satellite and displaying information on the reception state based on the calculation. 33. A non-geostationary satellite, which is used by switching a satellite to be used for a service, wherein data to be transmitted and received is relatively strict with respect to time and slow with respect to time. An information system characterized in that the two are separated in time series and transmitted and received, and the transmission and reception timings, which are slow in terms of time requirements, coincide with the satellite switching. 34. An information system according to claim 33, wherein the satellite to be used is switched without affecting the data transmission / reception although the time requirement is severe. 35. An information system according to any one of claims 33 to 34, characterized in that it is configured to perform satellite switching so as not to reduce the throughput during non-switching. 36. A non-geostationary satellite, which is used by switching between satellites provided for service, wherein the beam of the satellite after switching is exclusively short-termed with the satellite before switching at a predetermined time before the satellite switching. An information system characterized by performing a trial shot temporarily and performing necessary processing such as line reservation after the switch based on the line status with the satellite after the switch obtained from the test shot before the switch. 37. A non-geostationary satellite that is used by switching between satellites used for service is used. Predetermined after satellite switching so as to enable various operations of lines that cannot be used after satellite switching. An information system characterized in that the satellite before switching is used exclusively with the satellite after switching during the period. 38. Data is transmitted from a center station using a satellite which covers a satellite communication area by a plurality of beams,
The receiving terminal receives the content, the position of the terminal is predicted based on the positioning information on the terminal side, and the radio wave quality is estimated from the beam area information transmitted from the center station,
A communication system characterized in that a terminal transmits a request for maintaining radio wave quality to a center station when necessary, and the center station communicates with the terminal at a communication quality according to the request. 39. Data is transmitted from a center station using a satellite that covers a satellite communication area by a plurality of beams,
The receiving terminal receives the content, predicts the position of the terminal based on the positioning information on the terminal side, and obtains the beam of the area around the terminal obtained from the positioning information from the beam area information transmitted from the center station. After filtering the area, the radio wave quality of the area is estimated from the data, and when necessary, the terminal sends a request for maintaining the radio wave quality to the center station, and the center station sets the communication quality according to the request. A satellite communication system characterized by communicating with a terminal. 40. A means for receiving a signal from an artificial satellite to be serviced in a predetermined service area by moving in a non-geostationary satellite orbit, and receiving a signal from a predetermined satellite among the artificial satellites. And information from when the signal of the predetermined artificial satellite is substantially not received until when the signal of the alternative artificial satellite is substantially received,
A receiving apparatus comprising means for previously receiving from the predetermined artificial satellite. 41. A signal for receiving a signal from an artificial satellite to be serviced, which alternates in a predetermined service area by moving in a non-geostationary satellite orbit, in which a signal of a predetermined satellite among the predetermined artificial satellites can be received. And a means for receiving a signal from the alternative artificial satellite, and means for performing processing for switching from reception from the predetermined artificial satellite to reception from the alternative artificial satellite based on the received signal. Receiving device. 42. Means for receiving a signal from an artificial satellite to be serviced in a predetermined service area by moving in a non-geostationary satellite orbit, and receiving a signal from a predetermined satellite among the artificial satellites. After that, it is possible to substantially receive the signal from the substitute artificial satellite, and to supplement the missing information in the reception information from the substitute artificial satellite after the reception from the substitute artificial satellite becomes possible. The receiving device, further comprising means for receiving a signal from the predetermined artificial satellite. 43. Means for receiving a signal from an artificial satellite to be serviced instead of in a predetermined service area by moving in a non-geostationary satellite orbit, and receiving a signal from a predetermined satellite among the artificial satellites, After that, it is possible to substantially receive signals from the alternative artificial satellite, and after the reception from the alternative artificial satellite becomes possible, the reception switching to the predetermined artificial satellite is performed. A receiving device comprising means for transmitting the indicated signal. 44. Means for receiving a signal from an artificial satellite that is capable of servicing instead of in a predetermined service area by moving in a non-geostationary satellite orbit, and receiving a signal from a predetermined satellite among the artificial satellites. , After that, it becomes possible to substantially receive a signal from the alternative satellite, and when the signal from the alternative satellite cannot be received, a signal from the alternative satellite via the predetermined artificial satellite. A receiving device comprising means for requesting to receive. 45. A means for receiving a signal from an artificial satellite to be serviced in place of a predetermined service area by moving in a non-geostationary satellite orbit, wherein the artificial signal having a frequency corresponding to a geographical condition in the service area is used. A receiving device for receiving from a satellite, comprising means for detecting the frequency to be received, and receiving a signal from the artificial satellite which substitutes based on the detection. 46. A radio signal radiated to at least one of the radio signals radiated from an artificial satellite to cover different service areas,
Means for determining the present situation in receiving the radio signal or estimating the future situation, and a request for changing the radio signal from the artificial satellite so as to improve the reception state based on the judgment or estimation A receiving device having means for emitting a signal. 47. A radio signal radiated to at least one of the radio signals radiated from an artificial satellite to cover different service areas,
A receiving apparatus comprising: means for estimating a reception situation of a future radio wave signal; and means for issuing a request signal for selecting and requesting one of improvement in throughput and reception situation based on the estimation. 48. A radio signal radiated to at least one of the radio signals radiated from an artificial satellite to cover different service areas,
A receiving device comprising means for estimating a reception situation of a future radio wave signal and means for issuing a request for reception delay, throughput, reliability or a charge based on the estimation. 49. Receiving a signal from an artificial satellite that is serviced in an alternate manner by moving in a non-geostationary satellite orbit in a predetermined service area, and information of the predetermined satellite from a predetermined satellite among the artificial satellites and A receiving device comprising means for receiving a signal including information of the artificial satellite to be replaced, and means for performing processing for switching reception from the predetermined artificial satellite to the changing satellite based on the received information. . 50. Means for receiving a signal from an artificial satellite to be serviced in a predetermined service area by moving in a non-geostationary satellite orbit, and performing arithmetic processing based on the received signal. A receiving apparatus comprising means for calculating a reception state from the artificial satellite in the area and displaying information on the reception state based on the calculation. 51. A non-geostationary satellite orbit is moved to transmit a signal from an artificial satellite that substitutes for a predetermined service area, wherein a signal from a predetermined satellite among the artificial satellites is transmitted, and the predetermined artificial satellite is transmitted. A transmission method for transmitting information in advance from when the satellite signal is substantially not serviced until the alternative artificial satellite signal is substantially serviced. 52. A non-geostationary satellite orbit is moved to transmit a signal from an alternative artificial satellite in place of a predetermined service area, wherein the signal of a predetermined satellite among the predetermined artificial satellites is in a serviceable state. A transmission method of transmitting a signal from an artificial satellite and transmitting a signal for switching from the predetermined artificial satellite to the alternative artificial satellite. 53. Serving a signal from an alternate artificial satellite that moves in a non-geostationary satellite orbit and substitutes in a predetermined service area, and services a signal from a predetermined satellite among the artificial satellites.
After that, it is intended to substantially service signal reception from the alternative satellite, and to compensate for the missing information in the reception information from the alternative satellite after the signal service from the alternative satellite becomes possible. Transmission method to send a signal to. 54. A non-geostationary satellite orbit is moved to service a signal from an alternate satellite in a predetermined service area.
Serving a signal from a predetermined satellite of the artificial satellites, and then substantially receiving the signal from the alternative artificial satellite, wherein the predetermined signal is provided after the transmission from the alternative artificial satellite is serviced. A transmission method that substantially switches reception to the artificial satellite of. 55. Non-geostationary satellites orbiting to service signals from alternative satellites in a predetermined service area,
Serving a signal from a predetermined satellite of the artificial satellites, and subsequently substantially servicing a signal from the alternative satellite, when the signal from the alternative satellite cannot be serviced, A transmission method for servicing a signal from the alternate satellite via the predetermined satellite. 56. A non-geostationary satellite orbit is moved to service a signal from an artificial satellite that alternates in a predetermined service area, and a signal having a frequency according to a geographical condition in the service area is transmitted. A transmission method for transmitting information about a power frequency. 57. A signal for irradiating a corresponding area with a radio wave signal from an artificial satellite so as to cover different service areas, the signal being for judging the present situation in receiving the radio wave signal or for estimating the future situation. A transmission method that changes the radio signal when there is a request to improve the reception status. 58. A satellite is provided with a corresponding area to cover a different service area, and a signal for estimating the reception status of a future radio wave signal is transmitted to improve throughput or reception status. A transmission method that changes the transmission state accordingly when requested. 59. A radio signal is applied to at least one of the areas to cover different service areas from an artificial satellite, and information for estimating a future reception status of the radio signal is transmitted and a reception delay. , A transmission method that changes the transmission status in response to requests for throughput, reliability, or charges. 60. A non-geostationary satellite orbit is moved to serve by an alternative artificial satellite that replaces a predetermined service area, and information of the predetermined satellite and information of the alternative artificial satellite from a predetermined satellite among the artificial satellites. A transmission method of transmitting a signal including a signal, and performing a switching process when receiving a process for switching reception to the changing satellite.