JP6051736B2 - Power saving device and power saving method for ultra-small earth station - Google Patents

Description

  The present invention relates to a power saving device and a power saving method for a micro earth station.

  In a satellite communication system, DAMA (Demand Assigned Multiple Access) communication may be performed between a center station and a plurality of ultra-small earth stations via a communication satellite. Such a DAMA satellite communication system has a schematic configuration as shown in FIG.

  The DAMA satellite communication system is composed of a very small earth station (VSAT) 110 (110a to 110n: n is a positive integer), the center station 120, the communication satellite 130, and the center station 120 to the VSAT 110. A downlink 140, an uplink 141 from the VSAT 110 to the center station 120, and a line 142 used for a call between the VSAT 110.

  The center station 120 includes a DAMA control unit, and monitors and controls the status information of each VSAT 110. Therefore, the center station 120 regularly monitors the VSAT 110 via the communication satellite 130 using the downlink 140. Sending control data.

  At this time, all the VSATs 110 waiting for reception receive the monitoring / control data in a broadcast manner, and only the VSAT 110 whose identification number of the received monitoring / control data is addressed to the own station generates a response signal. This response signal is transmitted to the center station 120 via the communication satellite 130 using the uplink 141.

  Therefore, the VSAT 110 always receives the monitoring / control data from the center station 120 in the reception standby state, and always receives the monitoring / control data other than that addressed to itself.

  When a large-scale power outage occurs in the event of a disaster, the power supply to the VSAT 110 is performed by a UPS, a generator or the like, and the VSAT 110 is required to be used in a situation where the power capacity is limited. On the other hand, since VSAT is expected as a role of ensuring communication during a disaster, it is required to ensure a longer operation time even in a situation where the power supply capacity is limited. However, in VSAT where power saving is not considered, long-term operation becomes difficult due to power shortage.

  Thus, it is conceivable to perform power saving operation. For example, in Japanese Patent Application Laid-Open No. 2004-1128949, there is a proposal to shift to the power saving mode according to the remaining battery level and the type of application to be used.

Japanese Patent Application Laid-Open No. 2004-1128949

  However, since the configuration according to Japanese Patent Application Laid-Open No. 2004-128949 relates to a base station and a mobile terminal connected to a LAN or WAN line, communication is performed between the center station and a plurality of micro earth stations via a communication satellite. It cannot be applied to a micro earth station in a satellite communication system.

  In addition, the intermittent reception disclosed in the Japanese Patent Application Laid-Open No. 2004-128949 relates to communication during application / data transmission / reception, and in the technique for intermittent reception during standby until data communication is started. Absent.

  Accordingly, the main object of the present invention is to perform intermittent reception during standby until data communication is started in a satellite communication system that performs communication between a center station and a plurality of micro-earth stations via a communication satellite. It is an object to provide a power saving device and a power saving method for an ultra-compact earth station that can save power in the environment.

  In order to solve the above-mentioned problem, in the reception standby state, the mode is switched between the normal continuous reception mode and the intermittent reception mode in which power is supplied every predetermined time and reception is performed. The power saving device provided in the micro earth station that communicates with the micro earth station receives monitoring control data transmitted from the center station to a plurality of micro earth stations, and calculates the multiframe length from the monitoring control data. A monitoring control data receiving unit that outputs a signal indicating the calculated multiframe length to the reception mode control unit, and a signal indicating the remaining battery level by monitoring the remaining battery level installed in the micro earth station A power monitoring unit that outputs to the mode control unit and a traffic amount of data transmitted / received via the satellite are monitored and a signal indicating the traffic amount is output to the reception mode control unit A traffic monitoring unit, and a reception mode control unit that sets a time interval for intermittent reception according to the remaining battery capacity and / or traffic volume, and controls mode transition between the continuous reception mode and the intermittent reception mode. And

  In addition, a power-saving method that suppresses power consumption by switching to the normal continuous reception mode and the intermittent reception mode in which power is supplied every predetermined time and received is transmitted from the center station to a plurality of micro-miniature earth stations. Monitoring control data is received, the multi-frame length is calculated from the monitoring control data, a signal indicating the calculated multi-frame length is notified to the reception mode control unit, A power supply monitoring procedure that monitors the remaining battery level and outputs a signal indicating the remaining battery level to the reception mode control unit, and monitors the traffic volume of data sent and received via the satellite and receives a signal indicating the traffic volume In the traffic monitoring procedure output to the mode control unit and the reception mode control unit, the remaining battery level and / or prior traffic volume Intermittent reception time setting procedure that sets the interval of intermittent reception at a tasted time interval and an integer multiple of the multiframe length, and a reception mode that controls the mode change between continuous reception mode and intermittent reception mode And a control procedure.

  According to the present invention, in a satellite communication system that performs communication between a center station and a plurality of microminiature earth stations via a communication satellite, intermittent reception is performed while waiting for data communication to start. Power saving is possible. Furthermore, since the interval of intermittent reception can be optimally set according to the remaining battery capacity or the prior traffic volume or both, optimal power saving according to the state of the micro-earth station is possible.

1 is a block diagram of a DAMA communication satellite communication system according to an embodiment. FIG. It is the figure which illustrated the monitoring / control data transmitted to each VSAT from a center station. It is a timing chart when VSAT changes from continuous reception mode to intermittent reception mode using monitoring / control data. It is a timing chart of intermittent reception while VSAT is waiting for reception. It is a timing chart at the time of changing intermittent reception mode according to a battery remaining charge. It is a timing chart at the time of changing intermittent reception mode according to traffic amount. It is a timing chart at the time of receiving monitoring / control data from the center station during the intermittent reception mode in VSAT. It is a satellite communication system diagram of DAMA system applied to description of related technology.

  An embodiment of the present invention will be described. FIG. 1 is a block diagram of a DAMA communication satellite communication system according to this embodiment. The satellite communication system 2 mainly includes a plurality of very small earth stations (VSAT) 10 (10a to 10n), a center station 20, and a communication satellite 30. The center station 20 and the VSAT 10 transmit information via the line 40. Information is transmitted between the VSATs 10 via the line 42. Note that n is a positive integer.

  The center station 20 includes a radio unit 21, a DAMA control unit 22, and a display unit 23 as main components. The VSAT 10 includes a radio unit 11, a transmitter 12, a receiver 13, a battery 18, and a power source unit 19 as main components. The receiver 13 includes a monitoring control data receiving unit 14, a receiving mode control unit 15, a traffic monitoring unit 16, and a power supply monitoring unit 17.

  Then, the center station 20 sequentially transmits monitoring / control data to each VSAT 10 in units of frames via the communication satellite 30 using the downlink 40 in order to perform state monitoring and state control of the VSAT 10.

  FIG. 2 is a diagram illustrating monitoring / control data transmitted from the center station 20 to each VSAT 10. The monitoring / control data is composed of a frame D addressed to each VSAT 10, and each frame D includes a synchronization word D1 and a data part D2. The synchronization word D1 is a data area for storing fixed data for synchronizing with the monitoring / control data frame in the receiver 13 of the VSAT 10. The data portion D2 is a data area including station identification information of VSAT 10, control identification information, and multiframe start position information.

  In FIG. 2, the time (frame length) of one frame is Tf, and the period of monitoring / control data (multiframe length) is Tmf. This multi-frame length Tmf is the time from reception of a frame addressed to the own station until reception of the next frame addressed to the own station. Therefore, when n frames are transmitted (when there are n VSATs 10), the multiframe length is Tmf = Tf × n. However, n is a positive integer.

  FIG. 3 is a timing chart when the VSAT 10 transitions from the continuous reception mode to the intermittent reception mode using the monitoring / control data. When activated, the VSAT 10 operates in a continuous reception mode in which all downstream signals are always received. This is because, immediately after startup, the VSAT 10 cannot grasp the reception timing of the downlink signal transmitted from the center station 20 and addressed to itself. When the VSAT 10 is activated, the monitoring control data receiving unit 14 starts a process for detecting a synchronization word from the monitoring / control data.

  When the monitoring control data receiving unit 14 detects the synchronization word, it counts the number of times of detection. As a result, when the synchronization word is detected n times, the monitoring control data receiving unit 14 determines that synchronization is established and outputs a synchronization establishment signal to the reception mode control unit 15.

  Further, the supervisory control data receiving unit 14 calculates the multiframe length Tmf from the multiframe start position information included in the data unit D2 received during the continuous reception mode and the reception timing of the frame addressed to the own station. Then, when the calculation of the multiframe length Tmf is completed, the monitoring control data receiving unit 14 outputs a multiframe length calculation completion signal to the reception mode control unit 15. That is, the supervisory control data receiving unit 14 outputs a synchronization establishment signal and a multiframe length calculation completion signal to the reception mode control unit 15.

  When the reception mode control unit 15 receives the synchronization establishment signal and the multiframe length calculation completion signal from the monitoring control data reception unit 14, the reception mode control unit 15 switches the control from the continuous reception mode to the intermittent reception mode and puts the receiver 13 in the intermittent reception state. Control.

  Note that the method according to the present embodiment can be applied even when multiple frames are multiplexed and a higher frame exists.

  Next, the intermittent reception (reception in the intermittent reception mode) while the VSAT 10 is waiting for reception will be described with reference to FIG. Each VSAT 10 only needs to receive the monitoring / control data frame addressed to the own station during reception standby. Therefore, the reception mode control unit 15 cuts off the power supply to the monitoring control data receiving unit 14, the traffic monitoring unit 16, and the power monitoring unit 17 except when receiving a downlink signal addressed to the own station. Reduce power (transition to intermittent reception mode).

  That is, when each VSAT 10 receives the synchronization establishment signal and the multiframe length calculation completion signal at the reception mode control unit 15, the reception mode control unit 15 performs monitoring control data reception unit 14, traffic monitoring unit 16, and power supply monitoring unit 17. Set power supply to the OFF state. This power-off state continues for a time of Tf × (n−1) −Δt. Here, the time Δt is the time from when the monitoring control data receiving unit 14, the traffic monitoring unit 16, and the power supply monitoring unit 17 are supplied with power until they start up. Hereinafter, this time Δt is referred to as a rise time. Accordingly, power supply to the monitoring control data receiving unit 14, the traffic monitoring unit 16, and the power supply monitoring unit 17 is started before the time Tf × (n−1) when the downlink signal addressed to the own station is received by the rising time Δt. The

  On the other hand, the reception mode control unit 15 manages the multiframe length Tmf, and controls the power OFF / ON of the monitoring control data reception unit 14, the traffic monitoring unit 16, and the power supply monitoring unit 17 according to the multiframe length Tmf. Therefore, power is always supplied even during the intermittent reception mode.

  When the power is turned off, the traffic monitoring unit 16 and the power monitoring unit 17 cannot perform traffic monitoring and power monitoring, but the power is turned on at the intermittent reception interval Tmf. The reception mode control unit 15 is notified of the monitoring result.

  The power monitoring unit 17 monitors the remaining battery level of the own station and transmits the monitoring data to the reception mode control unit 15. Further, the traffic monitoring unit 16 monitors the traffic amount from the data received by the monitoring control data receiving unit 14 and transmits the monitoring data to the reception mode control unit 15. Then, the reception mode control unit 15 changes the intermittent reception mode based on the signals from the power supply monitoring unit 17 and the traffic monitoring unit 16.

  As described above, when the reception mode control unit 15 receives the synchronization establishment signal and the multiframe length calculation completion signal from the monitoring control data reception unit 14, the reception mode control unit 15 switches the control from the continuous reception mode to the intermittent reception mode, and receives the receiver 13. To the intermittent reception state. At this time, a plurality of modes with different reception intervals are set as the intermittent reception mode, and mode transition is performed according to a predetermined mode transition criterion.

  In the following description, a normal intermittent reception mode A, a long interval intermittent reception mode B, and a longer interval (long interval) intermittent reception mode C will be described. In addition, a description will be given assuming that the criteria for determining which intermittent reception mode is to be changed (mode transition criteria) is based on the remaining battery level and traffic volume. However, the present invention does not limit the intermittent reception mode to three (A, B, C), and the mode transition reference is not limited to the remaining battery level and traffic volume.

  First, the case where the transition to the intermittent reception mode is performed using the remaining battery level as the mode transition reference will be described with reference to FIG. FIG. 5 is a timing chart when the intermittent reception mode is changed according to the remaining battery level.

  The power monitoring unit 17 monitors the remaining battery level of the own station and transmits the monitoring data to the reception mode control unit 15. If the reception mode control unit 15 determines that the remaining battery level (Vc) is lower than a certain threshold value (Vc_1), the reception mode control unit 15 sets the interval of intermittent reception to reception in the normal intermittent reception mode A in order to suppress power consumption. Transition from the interval Tmf (= Tf × n) to the intermittent reception mode B (long interval intermittent reception mode) of the reception interval Tmf_1 (= Tmf × n) having a longer reception interval than this. Therefore, the transition to the intermittent reception mode B having a longer reception interval than the normal intermittent reception mode A is performed, and the power consumption is suppressed.

  Further, in the intermittent reception mode B, when it is determined that the remaining battery level (Vc) is further lower than the preset threshold value (Vc_2) (Vc_1> Vc_2), the reception mode control unit 15 The reception interval Tmf_1 is changed to the intermittent reception mode C (long interval intermittent reception mode) of the reception interval Tmf_2 (= Tmf × t) having a longer reception interval. Therefore, the transition to the intermittent reception mode C having a longer reception interval than the intermittent reception mode B is performed, and the power consumption is suppressed.

  On the other hand, when the remaining battery level increases, the reception mode control unit 15 shifts to a mode with a short reception interval.

  In addition, a case where a transition to the intermittent reception mode is performed using a traffic amount as a mode transition reference will be described with reference to FIG. FIG. 6 is a timing chart when the intermittent reception mode is changed in accordance with the traffic amount before changing to the intermittent reception mode.

  The traffic monitoring unit 16 monitors the traffic volume and transmits the monitoring data to the reception mode control unit 15. The reception mode control unit 15 determines an intermittent reception interval when transitioning to the intermittent reception mode based on the monitoring data. When transitioning to the intermittent reception mode, for example, when the traffic volume (Tc) is greater than a certain threshold value (Tc_1), the intermittent reception interval is set to the reception interval Tmf in the normal intermittent reception mode A in order to suppress power consumption. Transition from (= Tf × n) to the intermittent reception mode B (long interval intermittent reception mode) of the reception interval Tmf_1 (= Tmf × n) having a longer reception interval than this. Therefore, transition from the normal intermittent reception mode A to the intermittent reception mode B having a longer reception interval can suppress power consumption during reception standby.

  Further, in the intermittent reception mode B, when the traffic volume (Tc) is larger than the preset threshold value (Tc_2) (V1> V2), the reception mode control unit 15 determines the reception interval Tmf_1 in the intermittent reception mode B from From this, a transition is made to the intermittent reception mode C (long-long interval intermittent reception mode) of the reception interval Tmf_2 (= Tmf × t) having a longer reception interval. Accordingly, the intermittent reception mode B is changed to the intermittent reception mode C having a longer reception interval, and power consumption during reception standby can be suppressed. For example, if the amount of traffic is high when the battery level is low, the operation time can be secured by changing the standby intermittent reception interval to the intermittent reception mode with a longer reception interval than the normal intermittent reception mode. Effective when priority is given.

On the other hand, when the traffic volume decreases, the reception mode control unit 15 shifts to a mode with a short reception interval.
Further, in the above mode transition, it may be determined that the transition to the intermittent reception mode is not made depending on the remaining battery level or the traffic amount.

  In this way, it is possible to shift to the optimum intermittent reception mode according to the battery remaining amount and the traffic amount of the VSAT 10, and it is possible to reduce power consumption.

  Next, the case of returning from the intermittent reception mode to the normal mode will be described. FIG. 7 is a timing chart when monitoring / control data is received from the center station 20 during the intermittent reception mode in the VSAT 10. In FIG. 7, the case of a line designation signal is illustrated as an example of monitoring / control data from the center station 20.

  As described above, the monitoring / control data from the center station 20 is transmitted at the reception interval Tmf. Therefore, the reception mode control unit 15 determines the time for transmitting the downlink signal addressed to the own station based on the synchronization establishment signal, and the monitoring control data reception unit 14, the traffic monitoring unit 16, the power The power supply to the monitoring part 17 is set to an ON state.

  At this time, if the control identification information of the monitoring / control data is a health check signal (a signal for monitoring the line state), the intermittent reception mode is continued.

  On the other hand, when the control identification information of the monitoring / control data is a line designation signal, the monitoring control data receiving unit 14 notifies the reception mode control unit 15 that there has been a call request from another VSAT 10. With this notification, the reception mode control unit 15 returns the reception mode from the intermittent reception mode to the continuous reception mode.

  As described above, since the transition is made to a plurality of intermittent reception modes according to the mode transition criteria such as the remaining battery level and the traffic volume, appropriate power saving can be realized.

2 Satellite communication system 10 (10a-10n) VSAT
DESCRIPTION OF SYMBOLS 11 Radio | wireless part 12 Transmitter 13 Receiver 14 Monitoring control data receiving part 15 Reception mode control part 16 Traffic monitoring part 17 Power supply monitoring part 18 Battery 19 Power supply part 20 Center station 30 Communication satellite

Claims (6)

Transition to normal normal reception mode and intermittent reception mode in which power is supplied every predetermined time to perform reception, to the micro-earth station that communicates with the center station and other micro-earth stations via the communication satellite A power-saving device provided,
The monitoring control data transmitted from the center station to a plurality of the micro-miniature earth stations is received , and the multi-frame is determined from the multi-frame start position information and the reception timing of the frame addressed to the local station included in the monitoring control data A supervisory control data receiving unit for calculating the length;
A power supply monitoring unit that monitors the remaining amount of the battery mounted on the microminiature earth station and outputs a signal indicating the remaining battery amount;
When the mode of the micro earth station is changed, and at a time interval according to the remaining battery level and at a time interval that is an integral multiple of the multi-frame length, only a frame addressed to itself is supplied. And a reception mode control unit for receiving the power. A power saving device for a micro-earth station according to claim 1,
The reception mode control unit calculates a traffic amount from the monitoring control data, supplies power at a time interval according to the traffic amount, and at a time interval that is an integral multiple of the multiframe length, and A power-saving device for an ultra-small earth station characterized by receiving a frame addressed to it. A power saving device for a micro-earth station according to claim 1 or 2,
The power saving apparatus for a microminiature earth station, wherein the reception mode control unit makes a transition to a state in which reception is possible a predetermined time before reaching the time of the multiframe length. A power saving method that suppresses power consumption by mode transition to a normal continuous reception mode and an intermittent reception mode in which power is supplied and received every predetermined time,
A monitoring control data reception procedure for receiving monitoring control data transmitted from the center station to a plurality of micro earth stations and calculating a multiframe length from the monitoring control data;
A power supply monitoring procedure for monitoring the remaining amount of the battery mounted on the micro-earth station and outputting a signal indicating the remaining battery amount;
When the mode of the micro-miniature earth station is changed, and at a time interval corresponding to the remaining battery level, and at a time interval that is an integral multiple of the multiframe length, a frame addressed to itself is supplied. And a reception mode control procedure for enabling reception of a micro ground station. A power saving method for a micro-earth station according to claim 4,
The reception mode control procedure calculates the traffic volume from the monitoring control data, and automatically supplies power at a time interval corresponding to the traffic volume and at a time interval that is an integral multiple of the multiframe length. A power saving method for a micro earth station, characterized in that a frame addressed to the station can be received. A power saving method for a micro-earth station according to claim 4 or 5,
The reception mode control procedure includes a procedure for transitioning to a receivable state a predetermined time before reaching the time of the multi-frame length.

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