JP7275995B2 - Communication device and communication method - Google Patents

Description

The present invention relates to a communication device and a communication method, and more particularly to power saving technology for communication devices.

A radio base station operates on a battery when it cannot receive an external power supply due to the occurrence of a disaster or the like. However, since the battery capacity is finite, the wireless base station cannot continue service for a long period of time unless the service area, capacity, type of service provided, etc. are restricted.
Patent Literature 1 discloses a technique for appropriately setting operation parameters of a communication device to reduce power consumption.

Also, disasters and the like may cause failures in antennas, base station radio units, or transmission lines. In such a case, the radio base station will not be able to sufficiently cover the service area.
Patent Literature 2 discloses a technique in which, when a radio base station fails, another radio base station continues service using the same frequency.

Therefore, when a disaster occurs, it is necessary to reduce the power consumption of the base station while suppressing the shrinkage of the service area.

JP 2019-057851 A JP 2017-073645 A

As described above, when a disaster occurs, the radio base station needs to reduce power consumption while coping with the shrinkage of the service area.
The method described in Patent Literature 1 can reduce power consumption, but cannot prevent a reduction in service area.

Also, the method disclosed in Patent Document 2 is based on the premise that there are a plurality of base station apparatuses covering the same area. Therefore, the service area cannot be covered unless redundant base stations are used, and there is a problem in terms of cost.

An object of the present disclosure is to provide a communication device and a communication method capable of suppressing power consumption without reducing the service area.

The communication device according to the present disclosure can communicate using a first frequency band with a high priority for continued operation and a second frequency band with a low priority for continued operation, and each of the communicable areas is a plurality of A communication device that can be divided into cells, wherein, when a failure occurs in communication in the first frequency band, one of the plurality of cells in the second frequency band in which the failure has occurred is selected in the first frequency band. For a cell that overlaps with another cell, a radio function is used to substitute for communication in the failed cell, and at least one of the cells other than the cell for which communication is to be substituted among the plurality of cells of the second frequency band. The part comprises power management means for turning off or limiting radio functionality.

In the communication method according to the present disclosure, communication is possible using a first frequency band with a high priority for continued operation and a second frequency band with a low priority for continued operation, and each of the communicable areas is a plurality. wherein, when a failure occurs in communication in the first frequency band, one of the plurality of cells in the second frequency band in which the failure occurs For cells that overlap with the cells of the first frequency band, the wireless function is used to substitute communication in the failed cell, and among the plurality of cells of the second frequency band, the cells other than the cell that substitutes for the communication For at least some of the cells, the radio function is deactivated or restricted.

According to the present disclosure, it is possible to provide a communication device and a communication method capable of suppressing power consumption without reducing the service area.

1 is a configuration diagram showing the configuration of a communication device in the mode for carrying out the first invention; FIG. FIG. 4 is a schematic diagram showing an overview of cell suspension and replacement in the mode for carrying out the second invention. FIG. 4 is a schematic diagram showing an overview of the configuration of a base station apparatus and alternatives in the mode for carrying out the second invention; It is a schematic diagram showing an example of covering a primary cell using a secondary cell in the form for carrying out the second invention. It is a schematic diagram showing an example of covering a primary cell using a secondary cell in the form for carrying out the second invention. It is a figure which shows the setting example of a service element in the form for implementing 2nd invention. FIG. 10 is a diagram showing parameters required for scheduling in the mode for carrying out the second invention; FIG. 10 is a diagram showing an example of parameters required for scheduling in the mode for carrying out the second invention; FIG. It is an example of scheduling of the radio base station in the mode for carrying out the second invention. It is a figure which shows the time change of a battery residual amount in the form for implementing 2nd invention.

<First Embodiment>
FIG. 1 is a configuration diagram showing a communication device 100 according to the first embodiment. A communication device is, for example, a radio base station.
Communication device 100 includes communication unit 10 and power management unit 20 .
The communication unit 10 performs communication using a first frequency band with a high priority for continuation of operation and a second frequency band with a low priority for continuation of operation. An area in which the communication unit 10 can communicate using the first frequency band can be divided into a plurality of cells. An area in which the communication unit 10 can communicate using the second frequency band can be divided into a plurality of cells.

When a failure occurs in communication using the first frequency band, the power management unit 20 selects a cell that overlaps with the failed cell of the first frequency band among the plurality of cells of the second frequency band. As for , the radio function is used to substitute communication in the failed cell.
When a communication failure occurs, the power management unit 20 suspends or restricts the wireless function of at least some of the cells other than the cell that performs communication substitution among the plurality of cells of the second frequency band. process.

In the present embodiment, communication is alternated to prevent a reduction in the communication area, and among cells with low priority for continued operation, the radio functions of cells other than the cell to be alternated are suspended or restricted. Therefore, it is possible to save power while preventing the reduction of the communication area.

<Second embodiment>
FIG. 1 is a configuration diagram showing the configuration of a communication device according to the second embodiment. A communication device is a radio base station, and is a constituent element of a mobile communication terminal network composed of mobile communication terminals and a communication network (upper station).
The communication device has disaster station data. The disaster station data defines the cell operation configuration and operation priority when operating with batteries. A priority is a pattern of bands and cells that give priority to operation.
The communication unit 10 performs wireless communication with the mobile communication terminal.

The power management unit 20 calculates power consumption for each service element such as the communication method and the number of accommodated users. The power manager maintains a table for setting and managing the priority of each service element. The power management unit manages the remaining battery level and power consumption per unit time.
The power management unit 20 calculates the optimum combination/scheduling that allows the radio base station device to operate for the specified period from the remaining battery level installed in the radio base station device and the preset service period. control so that the operation can be continued. A preset service period may be specified by a higher node. The power manager may maintain the service period in memory of the control card. A schedule is generated based on the priority of each service component.
The power management unit 20 operates the communication unit according to the disaster station data and schedule during battery operation.

Each service element that determines power consumption is, for example, the number of carriers, the number of CAs (Carrier Aggregation), the transmission power modulation method, the number of accommodated (users), and the transmission capacity.
As for the number of carriers, power consumption of the transmitting/receiving section (RF section) can be suppressed by stopping carriers with low utilization rates. It should be noted that there is also the advantage that it is possible to aim at consolidating users into a frequency band with a high utilization rate by suspending carriers, and that it is possible to aim at improving the efficiency of accommodating users. The set value is, for example, 1 to 10 carriers.

The main purpose of CA is to improve user throughput, but since it occupies the processing resources of the base station, stopping the function makes it possible to accommodate more users (improve user accommodation efficiency). The set value is, for example, 1 to 10CA.
By changing the modulation method to low-value modulation (256QAM→64QAM→16QAM→QPSK), the amount of signal processing can be reduced and the power consumption can be reduced.

As for the number of accommodated users (users), by setting an upper limit on the number of accommodated users, it is possible to reduce the processing amount of the functional unit that manages user management and signal processing. The function unit is, for example, a baseband system function unit. The set value is, for example, 100 to 30,000 users.
Transmit power dominates power consumption, but reducing the transmit power reduces the serving cell radius. The set value is, for example, 0.1 to 20W.
Regarding the transmission capacity, the amount of processing can be reduced by reducing the amount of transmission data. The set value is, for example, 1 Mbps to 10 Gbps.

Power saving can be achieved by setting in the direction of reducing the processing related to each service element described above. For example, power saving can be achieved by reducing the performance of the CPU (reducing the clock frequency of the CPU or partially stopping the CPU core) or by stopping power supply to a part of the memory. Furthermore, if the functional unit responsible for the above processing is implemented in hardware that constitutes part of the device, such as a card or panel, power can be reduced by turning off the power for each card or panel. be.

Priorities are set for each of the above service elements when running on battery power, and optimal settings are made based on power consumption calculated in advance so that operation (service provision) can be performed during the specified service period. is scheduled.
When running on battery, it is possible to monitor whether the battery usage (power consumption) is as scheduled in real time, and if the usage exceeds the schedule, the settings may be reviewed and the schedule may be rescheduled.

Scheduling also depends on other elements that consume power, so it is not limited to the parameters mentioned above, but is also performed in consideration of heating/cooling equipment, various lighting, monitoring equipment, etc. that are supplied with the same power supply. .

Power consumption may be calculated for each control card, each functional unit, and each service element. Also, the power consumption may be updated and optimized by statistical means during actual operation. This method absorbs individual differences in hardware and eliminates the need to record patterns that are not implemented.

The operation in this embodiment will be described below. When the external power supply is cut off due to the occurrence of a disaster or the like and the radio base station becomes battery-powered, the radio base station operates in a preset disaster mode.
It is assumed that the radio base station can be battery-powered during a power failure, and that the area in which the radio base station can communicate is provided with services by a plurality of frequency bands. Frequency bands are classified into primary bands and secondary bands.

A primary band is a frequency band that many terminals support. Also, the secondary band is a subcarrier for high-speed communication and is subject to CA. The secondary band can be used as the primary band both during normal times and during disasters.

The radio base station operates according to the following criteria (1) to (4) in the disaster operation mode.
(1) When the transmission line connected to the base station control unit is cut, or the antenna or radio equipment fails, and the cell providing service using the equipment cannot be operated, Stop the equipment and stop the operation of the cell.
(2) Stop the operation of the secondary band cell whose service area does not overlap with the cell whose operation was stopped in (1). The cells whose operations are to be suspended are determined based on disaster station data and (1). However, the secondary cell whose service area overlaps with the cell whose operation was suspended in (1) will not be suspended in order to become the primary band.
(3) Stop operation of the radio equipment corresponding to the cell determined to be out of operation in (2).
(4) Stop the operation of surplus cards and redundant cards if they are used for communication. At this time, a process of turning off the power may be performed, or a process of reducing power consumption may be performed.

FIG. 2 is a schematic diagram showing an overview of cell decommissioning and replacement. FIG. 3 is a schematic diagram showing the configuration of the base station apparatus and an outline of alternatives. The operation of the cell, etc., is determined by disaster station data and the like.

In FIG. 2, when the external power supply is cut off and battery operation is performed, the primary band is assumed to be in operation, and the operation of the secondary band is stopped, thereby reducing the power consumption of the base station. Therefore, the secondary band cell No. 1 and No. 2 has been discontinued.
Cell No. of primary band 1; 3 is in an inoperable state for some reason (failure of the radio or disconnection of a cable in the transmission line). Therefore, the secondary band cell no. 3 continues operation without stopping.

Also, as shown in FIGS. 4 and 5, there are cases where the cell radius of the primary cell and the secondary cell are different. A method of substituting the primary cell in such a case will be described.

FIG. 4 shows a case where the secondary cell is larger than the primary cell, but one secondary cell cannot cover the primary cell. In a case like FIG. 4, a plurality of secondary cells are substituted to cover the primary band cells. In the case of FIG. 2, the primary band cells are covered by the secondary band cells (1) and (2).

FIG. 5 shows the case where the cell radius of the primary band is larger than the cell radius of the secondary band. A case where the cell radius of the secondary band is smaller than the cell radius of the primary band to be covered will be described below. In such a case, it is possible to cover an area equivalent to that of the primary band by changing the tilt angle of the antenna corresponding to the cell of the secondary band or increasing the transmission power of the antenna.

A case combining FIGS. 4 and 5 is also conceivable. In such a case, the primary band cell can be covered by a group of secondary bands with small cell radii.

Battery scheduling is described below.
As shown in FIG. 6, power consumption is calculated in advance for combinations of setting values of n service elements.

FIG. 7 is a diagram showing an example of other information necessary for scheduling when battery-powered. FIG. 7 shows operation duration time, remaining battery capacity, and operation policy as parameters. Parameters may be set as default values, specified from a remote node, or obtained in real time.
FIG. 8 is an example of parameters shown in FIG.

FIG. 9 is a diagram illustrating an example of battery scheduling. In FIG. 9, when the external power source is operated, the service is provided with setting n (power consumption of 5,000 Wh). In the case of the remaining battery level shown in FIG. 8, operation can be continued only for a maximum of two hours, and the regulation of operation duration cannot be satisfied. Here, by performing the scheduling shown in FIG. 9, it is possible to operate for 5 hours.
FIG. 10 is a diagram showing changes over time in the remaining battery capacity when scheduling is performed and when scheduling is not performed.

Note that the power consumption of a radio base station varies depending on the installation area of the radio base station, the number of users in the area, the time of day, and the like. Therefore, it is possible to collect statistics for each area and create the table shown in FIG. 6 for each time period. In such a case, it is possible to derive a more detailed combination as a setting for the relevant area during the time period in which the battery is driven, and reflect it in the schedule.

According to this embodiment, when there is no external power supply such as in an emergency, (1) the power of the wireless base station operating on the battery is reduced, and (2) the cell of the frequency band in operation cannot be operated due to a disaster or the like. If there are no more frequencies, it becomes possible to cover the same cell with another frequency band.
Therefore, even in the event of a disaster, a single base station can minimize service area reduction and maximize service provision time to extend service life.

The present embodiment can be applied to communication devices including mobile communication terminals as well as to radio base stations. In addition, it can be applied to equipment that normally uses an external power supply and that operates with a storage battery in an emergency.

10 Communication Unit 20 Power Management Unit 100 Communication Device

Claims (6)

A communication device capable of communicating using a first frequency band with a high priority for continued operation and a second frequency band with a low priority for continued operation, and dividing each communicable area into a plurality of cells. There is
When a failure occurs in communication using the first frequency band,
Among the plurality of cells of the second frequency band, for cells that overlap with the cell of the first frequency band in which the failure occurred, the wireless function is used to substitute communication in the cell in which the failure occurred;
power management means for suspending or limiting wireless functions of at least some of the cells of the second frequency band other than the cell that substitutes for communication;
A communication device comprising: Power management means for suspending the wireless function of all cells other than the cell that performs the communication substitution among the plurality of cells of the second frequency band;
The communication device of claim 1, comprising: The first frequency band is a primary band that ensures connectivity, and the second frequency band is a subcarrier for performing communication at a higher speed than the communication of the primary band,
3. A communication device according to claim 1 or 2. When the non-battery drive is switched to the battery drive, the power management means starts processing to stop or limit the wireless function of at least some of the cells other than the cell that performs the communication alternative.
A communication device according to any one of claims 1 to 3. A communication device capable of communicating using a first frequency band with a high priority for continued operation and a second frequency band with a low priority for continued operation, and capable of dividing each communicable area into a plurality of cells. A communication method in
When a failure occurs in communication using the first frequency band,
Of the plurality of cells of the second frequency band, for cells that overlap with the cell of the first frequency band in which the failure occurred, using a wireless function to substitute communication in the cell in which the failure occurred;
Of the plurality of cells of the second frequency band, suspending or restricting the wireless function for at least some of the cells other than the cell that performs the communication substitution;
Communication method. Of the plurality of cells of the second frequency band, suspending the wireless function of all cells other than the cell that performs the communication substitution;
The communication method according to claim 5.

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