JPH11175347A - Down line loading method for communication control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a memory capacity required for storing a communication control program. SOLUTION: At the time of activation, a control station multi-address transmits a transmission control program through a communication satellite to respective stations to be controlled (timing T1). The respective stations to be controlled receive the transmission control program from the stations to be controlled, operate a CPU based on the received transmission control program and perform transmission (timing T2). The stations to be controlled receive the transmission control program and transmit first response signals to the control station at the time of being normally activated. The control station also periodically transmits prescribed signals for health check to the stations to be controlled (timing T5), and in the case that no response is made from the stations to be controlled (timing T6), multi-address transmits the transmission control program again (timing T7). Thus, the stations to be controlled are not required to hold the transmission control program in a ROM or the like beforehand.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a satellite communication system including one control station and a plurality of controlled stations communicating with each other via a communication satellite. It's about how to load.

[0002]

2. Description of the Related Art In a conventional satellite communication system including one control station (also called a satellite communication control station) and a plurality of controlled stations (also called a satellite communication controlled station) which communicate with each other via a communication satellite. The controlled station stores the transmission control program and the reception control program in a ROM (Read On).
and a CPU (Central Processing Unit) is operated based on the transmission control program and the reception control program to control each unit such as a transmitter and a receiver to transmit and receive data between stations. It is carried out.

Further, the controlled station communicates with the control station at the time of startup, and if necessary, downloads a new transmission control program and reception control program from the control station, and obtains the acquired transmission control program and reception control program. To RAM (RandomAccess Memory)
y), the CPU is operated based on those programs to perform transmission and reception.

[0004]

Therefore, in this type of conventional satellite communication system, the controlled station holds the transmission control program and the reception control program to be downline loaded in advance together with the RAM for storing the same. A ROM for storing a transmission control program and a reception control program must be provided, which requires a large memory capacity as a whole, which is disadvantageous in terms of miniaturization and cost reduction of the apparatus.

SUMMARY OF THE INVENTION The present invention has been made in order to solve such a drawback, and an object of the present invention is to provide a communication control program which can reduce a memory capacity required for storing the communication control program. It is to provide a loading method.

[0006]

In order to achieve the above object, the present invention provides a satellite communication system including one control station and a plurality of controlled stations communicating with each other via a communication satellite. A method of down-line loading a communication control program from the control station, wherein the controlled station receives a transmission control program from the controlled station, operates a CPU based on the received transmission control program, and performs transmission. Performing, after receiving the transmission control program, transmitting a first response signal to the control station, and when receiving a predetermined signal for health check, transmitting a second response signal to the control station; The control station holds, for each controlled station, state identification information that takes one of the first and second states, and sets all of the state identification information to the second state at the time of startup. When at least one piece of the state identification information is in the second state, the transmission control program is broadcast to the controlled station, and when the first response signal is received from the controlled station, Setting the state identification information corresponding to a control station to the first state, periodically transmitting a predetermined signal for health check to the controlled station, and transmitting the predetermined signal to the controlled station; When the second response signal cannot be received from the station, the state identification information corresponding to the controlled station is set to the second state.

Therefore, in the downline loading method of the communication control program according to the present invention, the control station broadcasts the transmission control program to the controlled station at the time of startup, and the controlled station receives the transmission control program, The transmission can be performed by operating the CPU according to the received transmission control program. When necessary by the health check, the transmission control program is transmitted from the control station to the controlled station again. Therefore, the controlled station does not need to hold the transmission control program in advance, and only needs to hold the reception control program as the communication control program.
Memory capacity can be reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described based on embodiments with reference to the drawings. FIG. 1 is a timing chart showing a processing procedure based on an embodiment of a down-line loading method of a communication control program according to the present invention;
FIG. 2 is a configuration diagram showing a satellite communication system for down-loading a communication control program according to an embodiment of the present invention;
FIG. 3 is a block diagram showing a control station and a controlled station constituting the satellite communication system of FIG.

A satellite communication system 1 for down-loading a communication control program according to one embodiment of the present invention, as shown in FIG. It comprises one control station 4 and a plurality of controlled stations 6 installed on the ground.

Each of the control station 4 and each controlled station 6 has the same basic configuration, and includes a transmitter 8, a receiver 10, an antenna 11, a CPU 12, a ROM 14, and a RAM 16, as shown in FIG. ing. ROM 14 of control station 4
Stores a down line load control program including a transmission control program and a reception control program. The CPU 12 of the control station 4 operates based on the down line load control program stored in the ROM 14, By controlling the receiver 10, communication with the controlled station 6 is performed, and an operation related to down-line loading of the transmission control program in the controlled station 6 is performed. More detailed operation of the CPU 12 of the control station 4 will be described later.

On the other hand, a transmission control program for operating the CPU 12 in the controlled station 6 is stored in the RAM 16 of the control station 4. The state identification information corresponding to each controlled station 6 is also stored in the RAM 16 of the control station 4. This state identification information indicates whether the corresponding controlled station 6 is in the normal state or in the abnormal state. When the controlled station 6 is in the normal state, it is set to the first state, and When the control station 6 is in an abnormal state, it is set to the second state.

Only the reception control program is stored in the ROM 14 of the controlled station 6, and the CPU 12 of the controlled station 6
Operates based on the reception control program stored in the ROM 14, controls the receiver 10, and receives a signal from the control station 4 or a signal from another controlled station 6. More detailed operation of the CPU 12 of the controlled station 6 will be described later.

Next, the operation of the satellite communication system 1 will be described with reference to the timing chart of FIG. 1 to explain in detail one embodiment of the method of down-loading the communication control program according to the present invention. When the control station 4 is started, the CPU 12 of the control station 4 operates based on the downline load control program stored in the ROM 14, and first, all the state identification information stored in the RAM 16 is stored in the second memory. After setting the state, the operation proceeds to the original operation.

That is, the CPU 12 of the control station 4
It is checked whether the state identification information stored in M16 is the second state, and if at least one state identification information of the second state exists, the transmission control program is read from the RAM 16 and the transmission control program is cycled. Broadcast transmission to the controlled station 6. In this case, since all the state identification information is in the second state, the CPU 12 of the control station 4 starts broadcasting the transmission control program (timing T1).

On the other hand, in the example of FIG. 1, the first controlled station 6 is started at the timing T2, and the CPU 12 of the controlled station 6 executes the reception control program stored in the ROM 14 of the controlled station 6. The operation is started based on this, and immediately after that, the transmission control program broadcast from the control station 4 is received. The CPU 12 of the controlled station 6
The received transmission control program is stored in the RAM 16, and thereafter, the transmission operation is performed based on the transmission control program stored in the RAM 16. Then, the control station 4 immediately transmits the first response signal notifying that the transmission control program has been received and started normally.

When the control station 4 receives the first response signal, the CPU 12 sets the state identification information corresponding to the controlled station 6 that has transmitted the first response signal to the first state.
After that, the CPU 12 of the control station 4 starts the last controlled station 6 at the timing T3, and outputs the first controlled station 6 from the controlled station 6.
Until the response signal is received, the broadcast transmission of the transmission control program is continued. When receiving the first response signal from the last controlled station 6, the CPU 12 of the control station 4
Is also set to the first state, whereby all the state identification information becomes the first state. Therefore, the CPU 12 of the control station 4 stops the broadcast transmission of the transmission control program at the timing T4.

The CPU 12 of the control station 4 periodically performs a health check on each controlled station 6 periodically (timing T5). The CPU 12 of the control station 4 transmits a predetermined signal to the controlled station 6 as this health check, and at the controlled station 6 receiving the predetermined signal, the CPU 12 transmits a second response signal to the control station 4. . CP of control station 4
U12 determines that the controlled station 6 that has transmitted the second response signal is in the normal state, and the corresponding state identification information stored in the RAM 16 is left as the first state.
However, when the second response signal is not transmitted from the controlled station 6 even though the predetermined signal for the health check is transmitted, the controlled station 6 is determined to be in an abnormal state and stored in the RAM 16. The corresponding state identification information is set to the second state (timing T6).

Then, the CPU 12 of the control station 4 starts the periodic broadcast transmission of the transmission control program again (timing T7) because one of the state identification information is in the second state. As a result, the controlled station 6 in an abnormal state
Can receive the transmission control program again, and can resume the transmission operation based on the received transmission control program.

Therefore, in the present embodiment, the controlled station 6 does not need to hold the transmission control program in advance, and only needs to hold the reception control program as the communication control program. Can be reduced. As a result, the controlled station 6 can be reduced in size and cost. Also, in this embodiment, the transmission control program does not always transmit after startup, but transmits only when necessary after performing a health check.
The line is not occupied more than necessary for transmitting the transmission control program.

The present invention has been described based on the embodiments. However, this is merely an example, and the present invention can be implemented in various forms without being limited to this example. For example, when the controlled station 6 tends to be activated frequently in a specific time zone of the day, a timer is provided in the control station 4 and the transmission control program is broadcast only in that time zone. In this way, it is possible to avoid the useless use of the line, and to effectively use the line. It is also effective to change the cycle at which the control station 4 broadcasts the transmission control program according to the number of controlled stations 6 that are activated and in the normal state. That is, when the number of controlled stations 6 in the normal state is small, and therefore, when the number of state identification information in the second state is large, the traffic due to the original communication is small and the communication line is relatively free. The period of the broadcast is set to be short so that the controlled station 6 can be started quickly. On the other hand, when the number of controlled stations 6 in the normal state is large, that is, when the number of state identification information in the second state is small, the period of the broadcast transmission is set to be long, and the line is avoided while occupying the line. Use as much of the original communication as possible.

[0021]

As described above, according to the present invention, in a satellite communication system including one control station and a plurality of controlled stations communicating with each other via a communication satellite, the controlled station communicates with the control station. A method of down-loading a control program, wherein the controlled station receives a transmission control program from the controlled station, performs a transmission by operating a CPU based on the received transmission control program,
After receiving the transmission control program, a first response signal is transmitted to the control station. When a predetermined signal for health check is received, a second response signal is transmitted to the control station. The station holds, for each controlled station, state identification information that takes one of the first and second states, sets all of the state identification information to the second state at the time of startup, and sets at least one of the state identification information. When the information is in the second state, the transmission control program is broadcast to the controlled station, and when the first response signal is received from the controlled station, the state corresponding to the controlled station is transmitted. The identification information is set to the first state, a predetermined signal for health check is periodically transmitted to the controlled station, and a second response signal is transmitted from the controlled station that has transmitted the predetermined signal. If you cannot receive And sets the state identification information corresponding to said second state.

Therefore, in the downline loading method of the communication control program of the present invention, the control station broadcasts the transmission control program to the controlled station at the time of starting, and the controlled station receives the transmission control program, The transmission can be performed by operating the CPU according to the received transmission control program. When necessary by the health check, the transmission control program is transmitted from the control station to the controlled station again. Therefore, the controlled station does not need to hold the transmission control program in advance, and only needs to hold the reception control program as the communication control program.
Memory capacity can be reduced. as a result,
The size and cost of the controlled station can be reduced. Further, in the present invention, the transmission control program is not always transmitted after activation, but is transmitted only when necessary after performing a health check. Therefore, a line is occupied more than necessary for transmission of the transmission control program. There is no end.

[Brief description of the drawings]

FIG. 1 is a timing chart showing a processing procedure based on an embodiment of a downline loading method of a communication control program according to the present invention.

FIG. 2 is a block diagram showing a satellite communication system for down-loading a communication control program according to an embodiment of the present invention.

FIG. 3 is a block diagram showing a control station and a controlled station constituting the satellite communication system of FIG. 2;

[Explanation of symbols]

1 ... satellite communication system, 2 ... communication satellite, 4 ... control station, 6 ... controlled station, 8 ... transmitter, 10 ... receiver,
11 ... antenna, 12 ... CPU, 14 ... ROM,
16 RAM.

Claims (7)

[Claims] In a satellite communication system including one control station and a plurality of controlled stations communicating with each other via a communication satellite, the controlled station down-loads a communication control program from the control station. The controlled station receives a transmission control program from the controlled station, performs a transmission by operating a CPU based on the received transmission control program, and, after receiving the transmission control program, A response signal is transmitted to the control station. When a predetermined signal for health check is received, a second response signal is transmitted to the control station. The control station is configured to perform any one of the first and second states. Holding the state identification information for each controlled station, setting all the state identification information to the second state at the time of starting, and at least one of the state identification information is the second state. When the time of the state is that broadcasts originating the transmission control program in the controlled station, receiving the first response signal from the controlled station,
The state identification information corresponding to the controlled station is set to the first state, a predetermined signal for health check is periodically transmitted to the controlled station, and the predetermined signal is transmitted. If the second response signal cannot be received from the controlled station, the state identification information corresponding to the controlled station is set to the second state. 2. The controlled station holds only a reception control program immediately after startup, and operates a CPU based on the reception control program to receive the transmission control program from the control station. The downline loading method of a communication control program according to claim 1. 3. The method according to claim 2, wherein the controlled station stores the reception control program in a ROM. 4. The downline loading method of a communication control program according to claim 1, wherein said controlled station stores said transmission control program in a RAM. 5. The first state of the state identification information,
The controlled station corresponding to the state identification information indicates that the controlled station is in a normal state, and the second state of the state identification information indicates that the controlled station corresponding to the state identification information is in an abnormal state. The down-line loading method of a communication control program according to claim 1, wherein: 6. The down line of the communication control program according to claim 1, wherein the control station broadcasts the transmission control program to the controlled station only in a specific time zone of a day. Loading method. 7. The control station, when at least one of the state identification information is in the second state, repeatedly broadcasts the transmission control program to the controlled station at a predetermined cycle. When the number of the state identification information of the state is large, the predetermined period is set short, and when the number of the state identification information of the second state is small, the predetermined period is set long. A downline loading method for the communication control program according to claim 1.