JP7355689B2 - Control device, control method, and program for flexible radio resource allocation - Google Patents

Description

The present invention relates to radio resource allocation control technology.

In response to the increasing demand for wireless communications, many frequency bands have been allocated for wireless communications. On the other hand, since there is a limit to the amount of available frequency resources, the same frequency resources may be shared by multiple wireless communication systems. As an example, radio resources are allocated such that frequencies used by a system such as a satellite communication system are also used by other systems such as a cellular communication system. In such frequency bands, interference from new systems to existing systems is ensured to be sufficiently suppressed. For example, in the relationship between a cellular communication system and a satellite communication system, adjustments are made so that the total amount of interference from the cellular communication system to the satellite communication system is below a predetermined value. For example, based on the distance and antenna angle from the base station of a cellular communication system surrounding the ground station of a satellite communication system to that ground station, the downlink signal from each base station is changed to the downlink signal to the ground station of the satellite communication system. The amount of interference provided is estimated, and the transmittable power of each base station is statically determined.

Interference with a second system, such as a satellite communication system, as long as each communication device of the first system, such as a base station of a cellular communication system, emits radio waves within the statically determined transmittable power range. The total amount never exceeds a predetermined value. On the other hand, the transmittable power determined for each communication device of the first system is such that even if those communication devices transmit radio waves at the maximum value of their transmittable power, the amount of interference to a specific system is It is designed so that it does not exceed a predetermined value. For this reason, it is assumed that transmission power may be suppressed excessively in some cases, making it impossible to utilize frequency resources with sufficiently high efficiency.

The present invention provides a technique for improving frequency usage efficiency in an environment where multiple systems coexist.

A control device according to one aspect of the present invention includes: specifying means for specifying, with respect to data to be transmitted in each of a plurality of base stations of a first wireless communication system, the amount of radio resources to be used for transmitting the data; Based on the amount of the radio resources and the amount of interference with the communication of the second radio communication system by the radio waves when radio waves are transmitted using a predetermined amount of radio resources from each of the plurality of base stations, allocation means for dynamically allocating radio resources for signal transmission in each of the plurality of base stations within a range that does not exceed an amount of interference tolerable to the second wireless communication system ; , determining whether or not to provide each of the services based on the priority of the service to be provided at each of the plurality of base stations and the amount of radio resources scheduled to be used for the service; Radio resources are dynamically allocated to each of the plurality of base stations .

According to the present invention, it is possible to improve frequency usage efficiency in an environment where a plurality of systems coexist.

1 is a diagram illustrating a configuration example of a wireless communication system. FIG. 2 is a diagram showing an example of a hardware configuration of a control device. It is a figure showing an example of functional composition of a control device. FIG. 3 is a diagram illustrating an example of a process flow. FIG. 3 is a diagram illustrating an example of radio resource allocation in consideration of allowable delay.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the claimed invention, and not all combinations of features described in the embodiments are essential to the invention. Two or more features among the plurality of features described in the embodiments may be arbitrarily combined. In addition, the same or similar configurations are given the same reference numerals, and duplicate explanations will be omitted.

(System configuration)
FIG. 1 shows a configuration example of a wireless communication system according to this embodiment. In one example, this wireless communication system is a cellular communication system, and includes a control device 101 and a plurality of base station devices (a first base station device 111, a second base station device 112, and a third base station device 113). It consists of: These base station devices are, for example, base station devices compliant with the Long Term Evolution (LTE) standard. The device is configured to be able to perform wireless communication with a terminal device that complies with the LTE standard.

Here, when transmitting a signal from an LTE base station device to an LTE terminal device, a radio frequency band used in a satellite communication system may be used. Therefore, the signal transmitted from the LTE base station device may interfere with the communication of the ground station 121 of the satellite communication system. In FIG. 1, white arrows indicate signals transmitted from LTE base station devices, and black arrows indicate the influence of interference caused by the signal transmission. Note that the thickness of the black arrow roughly indicates the intensity of interference. In other words, each base station device transmits a signal with a predetermined power to the connected terminal device, but the amount of interference to the satellite communication varies depending on the distance from the satellite communication ground station 121 and the presence or absence of line-of-sight. sell. In the example of FIG. 1, the interference caused by the signal transmitted from the first base station device 111 is large, followed by the interference caused by the signal transmitted from the second base station device 112, and the interference caused by the signal transmitted from the third base station device 113 is large. This shows that the interference caused by the transmitted signal is the smallest. In such an environment, the LTE base station device needs to perform communication so that the amount of interference to the ground station 121 of the satellite communication system does not exceed the allowable amount of interference. For this reason, conventionally, in order to prevent the amount of interference to the satellite communication ground station 121 from exceeding the interference tolerance, it has been determined whether each base station device can use the frequency band and whether each base station device can output the frequency band. The maximum value of transmission power is statically set in advance. For example, the first base station device 111 is prohibited from using that frequency band, and the second base station device 112 and the third base station device 113 are each prohibited from using other frequency bands, for example, with a lower power density. Settings such as setting the value to 1/100 of the actual value may be performed. Note that the contents of these settings are determined by theoretical calculations based on antenna characteristics such as the distance between each base station device and the ground station 121 and the antenna gain for each direction of the base station device and the ground station 121. It can be done. Then, a base station device that is set to be allowed to use that frequency band transmits a signal within a preset maximum transmission power range. As a result, at the ground station 121 of the satellite communication system, the total amount of interference caused by the signals transmitted from each base station device will fall within the interference tolerance range, and LTE communication will interfere with the communication of the satellite communication system. This can be prevented.

However, if such a static configuration is performed, the total amount of interference at ground station 121 may be significantly lower than the interference tolerance. For example, most of the base station apparatuses that are permitted to use the frequency band used in the satellite communication system do not use that frequency band, so that the amount of interference is reduced. For example, only the second base station device 112 and the third base station device 113 are allowed to use the frequency band, and the third base station device 112 uses the maximum transmission power set in the frequency band. If the second base station device 113 does not use that frequency band while transmitting a signal in that frequency band, the ground station 121 may receive interference of only about half the power of the interference tolerance, for example. . In particular, the second base station device 112 and the third base station device 113 cannot transmit signals with sufficient power density when using the frequency band used in satellite communication, and some terminal devices It is conceivable that it may not be possible to provide communication with sufficient quality to the users. Therefore, the frequency with which this frequency band is used decreases, and the frequency utilization efficiency of the system as a whole may decrease.

In view of these circumstances, this embodiment removes the limitations on the availability of frequency bands used in satellite communications and the allowable transmission power, which were statically set for each base station device, and dynamically allocate wireless resources to For example, in the past, if the first base station device 111, which was set not to use the frequency band for satellite communication, is not using that frequency band by another base station device, the first base station device 111 would It may be permissible to use frequency bands. Further, the third base station device 113 can increase the usable power density when the second base station device 112 does not use the frequency band. In this way, in this embodiment, the control device 101 does not statically determine in advance whether or not the frequency band used in satellite communication can be used or the maximum value of transmission power for each individual base station device. Dynamically control base station devices collectively. This makes it possible to improve frequency usage efficiency while preventing the amount of interference to satellite communications from exceeding the allowable amount of interference.

In this embodiment, the control device 101 specifies the amount of radio resources to be used for transmitting data for each of a plurality of base station devices. Then, the control device 101 determines based on the amount of radio resources and the amount of interference to satellite communication caused by the radio waves when radio waves are transmitted using a predetermined amount of radio resources from each of the plurality of base station devices. , dynamically allocate radio resources for signal transmission in each of a plurality of base station devices within a range that does not exceed the allowable amount of interference to satellite communications. Each base station The total amount of interference caused when the device transmits each of the data scheduled to be transmitted can be determined. Note that when radio waves are transmitted using a predetermined amount of radio resources from each of multiple base station devices, the amount of interference to satellite communication due to the radio waves is based on the amount of interference caused by the radio waves when the base station device and the ground station for satellite communication are fixed stations. Therefore, it is generally a fixed value. However, the present invention is not limited to this, and a value that fluctuates may be used, for example, when the base station device or ground station moves or when visibility is not secured. When the value of the amount of interference changes, the value can be updated based on, for example, the measurement results at the ground station of radio waves transmitted by the base station device. Then, the control device 101 executes radio resource allocation so that, for example, the total amount of interference does not exceed the allowable amount of interference for satellite communication. This makes it possible to improve frequency usage efficiency while preventing the amount of interference to satellite communications from exceeding the allowable amount of interference. Note that the estimation of the total amount of interference does not necessarily need to be performed, and the estimation of the total amount of interference is not necessarily performed, but is estimated based on the amount of radio resources that each base station device is expected to use in transmitting data. A table or the like that defines the amount of radio resources that can be allocated may be used.

Note that the control device 101 determines the priority of each of the services based on the priority of the service to be provided in each of the plurality of base station devices and the amount of radio resources scheduled to be used for the service. You can decide whether or not to provide it. For example, the control device 101 allocates radio resources in descending order of priority within a range that does not exceed the interference tolerance. At this time, the control device 101 may determine that the service cannot be provided if, for example, it is assumed that executing a service with a relatively low priority would exceed the interference tolerance. In this case, the control device 101 decides to allocate radio resources to this service at another timing, such as the next subframe, for example. As a result, among multiple base station devices, radio resources are preferentially allocated to the base station device whose service to be provided to the terminal has a high priority, and that base station device provides the service with the high priority. You will be able to do this. In this way, by flexibly and dynamically allocating radio resources between multiple base station devices, radio resources can be allocated in a way that satisfies the quality of service while suppressing interference with satellite communications. becomes possible.

Note that when a first service is to be newly provided in at least one of a plurality of base station devices, the control device 101 determines the priority of the first service and the wireless resources scheduled to be used. and the priority of the second service being performed and the amount of radio resources that are expected to be used. That is, the control device 101 determines whether to give priority to a service that is currently being executed or a service that is scheduled to start, and allocates radio resources to the base station device that provides the service that should be given priority. do. Further, the control device 101 can determine whether to stop the second service based on the priorities of the first service and the second service and the amount of radio resources scheduled to be used. . That is, the control device 101 determines whether to give priority to a service that is currently being executed or a service that is scheduled to start, and, for example, cancels the service that is currently being executed when a new service should be given priority. Decide whether or not to do so. In this way, by considering not only existing communication services but also new services, it becomes possible to allocate radio resources more flexibly while suppressing interference with satellite communication.

At this time, the control device 101 can acquire information regarding at least one of the first service and the second service from each of the plurality of base station devices. This information may include information that can specify the priority, such as information indicating the priority and a service identifier. Further, the information regarding the first service is information indicating the amount of radio resources to be used when performing communication related to the service with the terminal device to which the first service is to be provided, or the amount of the radio resources. may include information that allows estimation of The information regarding the second service is information indicating the amount of radio resources that should be used when communicating with the terminal device to which the second service is provided, or the amount of radio resources. Contains identifiable information. Note that since the first service is a service that has not yet been executed and the second service is a service that is being executed, the characteristics of the information may be different. For example, the information regarding the first service includes information on the radio quality between a terminal device and a base station device “scheduled to provide” the first service to the terminal device. On the other hand, the information regarding the second service includes information on the radio quality between the terminal device and the base station device "providing" the second service to the terminal device. Note that the information regarding the first service is acquired by establishing a radio resource control (RRC) connection between a terminal device and a base station device that provides the first service to the terminal device. In other words, a terminal device that is scheduled to receive the first service once connects to a base station device that is scheduled to provide that service, and then transmits, for example, the measurement results of wireless quality to the base station device. Notice. Note that the terminal device can establish an RRC connection with the base station device regardless of whether the first service is actually provided to the terminal device. That is, the terminal device may not be provided with the first service as a result of establishing an RRC connection and reporting the wireless quality measurement results. Note that since the terminal device receiving the second service is connected to one of the base station devices, that base station device can check the wireless quality with that terminal device at any timing during communication. It can be obtained with.

In addition to the above-mentioned information, the control device 101 can obtain information such as the requested throughput of the service, the allowable delay, and the allowable error rate (for example, the allowable block error rate). This information can be stored in advance in a database in association with, for example, information that specifies a service. The control device 101 can, for example, search a database using information specifying the first service and the second service, and obtain information corresponding to each of these services. The control device 101 then uses the obtained information, such as the allowable block error rate, regarding the wireless quality between the terminal device and the base station device that is/scheduled to provide the service for each terminal device, for example. The modulation and coding scheme (MCS) to be used in communication with the terminal device may be identified to satisfy the based conditions. Then, the control device 101 specifies the amount of radio resources (for example, the number of physical resource blocks) that can satisfy further conditions based on the acquired information, such as requested throughput and allowable delay, using the specified MCS. can do. In this way, the amount of radio resources when the first service is executed can be estimated, and the amount of radio resources when the second service is executed can be specified.

Regarding the first service, since the terminal device may be in a state where it is not connected to the base station device, the radio quality may be reported once the RRC connection is established as described above, but the radio quality There is no need to report. If such reporting is not performed, it is assumed that the wireless quality between the terminal device and the base station device is at the lowest level within the communicable range, such as the lowest level specified by the standard. The amount of radio resources when the first service is executed may be estimated. In addition, based on the statistical data of the wireless quality within the service area where the base station device that is scheduled to provide the first service to the terminal device can provide the service, the wireless quality between the terminal device and the base station device is determined. may be estimated. For example, the average wireless quality within the service area, the lowest wireless quality, the wireless quality obtained by 90% of the terminal devices, etc. can be used as the estimated wireless quality between the terminal device and the base station device. Note that this wireless quality statistical data can be updated based on the wireless quality measured after the first service is provided and communication is started.

The control device 101 uses the transmission power (power density per frequency) of each base station device, radio resource allocation information, the distance between each base station device and the ground station 121, and antenna characteristics to control the LTE base station. Each of the devices calculates the amount of interference given to the satellite communication ground station 121. Then, the control device 101 selects the services to be provided so that the total amount of interference does not exceed the allowable amount of interference. For example, the control device 101 adds the amount of interference based on the amount of wireless resources estimated for the first service that is not being executed to the total amount of interference that is based on the amount of wireless resources specified for the second service that is being executed. Then, if the value of the calculation result does not exceed the interference tolerance, it can be determined that the first service is executable. On the other hand, if the value of the calculation result exceeds the interference tolerance, the control device 101 may, for example, refuse to accept the first service. Further, if the value of the calculation result exceeds the interference tolerance, the control device 101 may, for example, stop providing a service with a lower priority among the second services. This makes it possible to flexibly allocate radio resources by taking into account the interference that both new services and ongoing services have on satellite communications. Note that when radio resources are allocated, base station devices to which radio resources are allocated may be adjusted based on the allowable delay of each service. This process will be described later.

Note that although FIG. 1 shows a configuration in which the control device 101 exists outside the base station device, the control device 101 is not limited to this. That is, the control device 101 may be included in some or all of the plurality of base station devices. When a plurality of control devices 101 exist, information is shared between the control devices 101, and the above-described processing can be executed by the cooperation of the plurality of control devices 101. Note that the above configuration may be applied to, for example, a Centralized-RAN (Radio Access Network). In this case, the control device 101 may operate as a CU (Central Unit), and the base station device may operate as a DU (Distributed Unit). In this case, the control device 101 can grasp the services to be provided to the terminal device, the wireless quality between the terminal device and the base station device, etc., and therefore executes special processing to obtain this information. do not have to.

Up to this point, the explanation has been made in the context of LTE communication control for suppressing interference with satellite communication, but the present invention is not limited to this. That is, in any system where it is necessary to suppress interference from a second wireless communication system that is not prioritized so that the amount of interference to communication of the first wireless communication system that is prioritized does not exceed the interference tolerance amount. , it is possible to apply the discussion according to this embodiment.

An example of the configuration of the control device 101 as described above and an example of the flow of processing to be executed will be described below.

(Device configuration)
FIG. 2 shows an example of the hardware configuration of the control device 101 according to this embodiment. In one example, the control device 101 is configured to include a processor 201, a ROM 202, a RAM 203, a storage device 204, and a communication circuit 205. The processor 201 is a computer that includes one or more processing circuits such as a general-purpose CPU (central processing unit) or an ASIC (application-specific integrated circuit), and is stored in a ROM 202 or a storage device 204. By reading and executing the program, the entire processing of the control device 101 and each of the above-mentioned processing are executed. The ROM 202 is a read-only memory that stores information such as programs and various parameters related to processing executed by the control device 101. The RAM 203 is a random access memory that functions as a work space when the processor 201 executes a program and also stores temporary information. The storage device 204 is configured by, for example, a removable external storage device. The communication circuit 205 is configured to include, for example, a circuit for wired communication or wireless communication with the base station device 102, the base station device 121, etc. Note that although one communication circuit 205 is illustrated in FIG. 2, the control device 101 may have a plurality of communication circuits. For example, the control device 101 may have a communication circuit for communicating with other network nodes, in addition to a communication circuit for communicating with the base station device 102.

FIG. 3 shows an example of the functional configuration of the control device 101 according to this embodiment. Note that in the configuration of FIG. 3, in order to simplify the explanation, only portions related to the processing according to this embodiment are shown, and other functions are omitted. For example, when the control device 101 operates as a CU of Centralized-RAN, it naturally has a control function as a CU, but this function is not illustrated. Some or all of the functions in FIG. 3 can be realized, for example, by the processor 201 executing a program stored in the ROM 202 or the storage device 204. However, the present invention is not limited to this, and some or all of the functions in FIG. 3 may be implemented by dedicated hardware. The control device 101 has, as its functional configuration, an information acquisition section 301, a resource amount identification section 302, an interference amount determination section 303, and a resource allocation section 304, for example. Note that the details of the processing in each functional unit are as described above, so a specific explanation may be omitted.

The information acquisition unit 301 acquires information regarding communication services provided to each terminal device, for example, from each base station device or from a database holding information used when controlling communication of each base station device in the own device. Get information. For example, the information acquisition unit 301 acquires information that can identify the priority of the service, such as identification information of a service that the base station device plans to start providing to the terminal device or a service that the base station device is currently providing to the terminal device. get. Note that when the control device 101 acquires the identification information of a service, it refers to information that associates the identification information with the priority to identify the priority of the service. Additionally, the information acquisition unit 301 can acquire information such as the data size of data transmitted and received in each service, required throughput, allowable error rate (allowable block error rate), allowable delay, and required wireless quality in the terminal device. . Furthermore, the information acquisition unit 301 can acquire information on wireless quality between each base station device and each terminal device.

The resource amount identifying unit 302 identifies the amount of radio resources to be used for transmitting data to be transmitted from each base station device to a terminal device. The resource amount specifying unit 302 determines the MCS to be used, for example, for a newly executed service, based on the radio quality of the terminal device to which the service is provided and the service's allowable error rate. Then, the resource amount specifying unit 302 estimates the amount of radio resources required to provide the service based on the MCS, the data size of data for providing the service, and the requested throughput. Further, the resource amount specifying unit 302 also specifies the amount of radio resources necessary to continuously provide the service that is being executed, for example, in the same manner. Note that, for a service that is currently being executed, the resource amount identifying unit 302 determines the amount of necessary wireless resources based on the performance of communications performed while the service is being executed, for example, based on highly accurate wireless quality information. quantity can be specified.

The interference amount determination section 303 predicts interference to satellite communication based on the amount of radio resources specified by the resource amount identification section 302. For example, the interference amount determining unit 303 determines the amount of radio resources required by each base station device to provide services, and the distance and antenna characteristics between the base station device and the satellite communication ground station 121. , estimate the amount of interference to satellite communications assuming that each base station device provides services.

Resource allocation section 304 allocates radio resources to each base station apparatus based on the predicted amount of interference. Resource allocation section 304 selects one or more base station devices to which radio resources are to be allocated, for example, for each subframe, so that the amount of interference to satellite communication does not exceed the interference tolerance. For example, the resource allocation unit 304 first determines whether the estimated value of the amount of interference exceeds the allowable amount of interference when wireless resources are allocated to the service with the highest priority. If the resource allocation unit 304 determines that the estimated value of the amount of interference exceeds the allowable amount of interference, the resource allocation unit 304 determines that the service with the highest priority cannot be provided, and refuses to provide that service. . Note that this service may be provided using, for example, another frequency band, but a detailed explanation of its allocation will be omitted here. Retained as the estimated total amount of interference. On the other hand, if the resource allocation unit 304 determines that the estimated value of the amount of interference does not exceed the allowable amount of interference, it determines that the service can be provided, and holds the estimated value as the estimated value of the total amount of interference. Next, the resource allocation unit 304 adds the estimated value of the amount of interference when allocating radio resources to the held total estimated amount of interference for the service with the next highest priority, and calculates the allowable amount of interference. Determine whether or not it exceeds. If the resource allocation unit 304 determines that the value resulting from the addition does not exceed the allowable amount of interference, it determines that the service can be provided, and updates the estimated total amount of interference with the value resulting from the addition. On the other hand, if the resource allocation unit 304 determines that the value resulting from the addition exceeds the interference tolerance, it determines that the service will not be provided at this timing, and then performs the same process for the next highest priority service. repeat. In this way, services to be provided are selected in order of priority within a range where the total amount of interference does not exceed the allowable amount of interference, and base station devices to which radio resources are allocated are determined accordingly. Note that radio resources may be assigned to a base station device to which radio resources are not assigned here in another subframe.

Note that the above resource allocation process is executed for each service. That is, when one base station device provides multiple services to one or more terminal devices, the amount of interference is evaluated for each service, and it is selected for which service radio resources should be used. , radio resources are allocated to the base station device that executes the selected service. Note that when radio resource allocation is completed in an allocation unit such as one subframe, the above-mentioned total interference amount estimate is reset to zero, and radio resource allocation in the next allocation unit is executed. Furthermore, the priority of a service to which radio resources have been allocated may be lowered.

Note that the radio resource allocation may be, for example, permission to use all of the available frequency bands for each subframe, or permission to use only a part of the available frequency bands. In other words, if it is possible to adjust the amount of interference to satellite communication by using only some frequency resources, fine-grained control of the amount of interference can be performed by allocating a limited amount of frequency resources. This makes it possible to further improve frequency usage efficiency.

(Processing flow)
An example of the flow of processing executed by the control device 101 will be described using FIG. 4. The control device 101 first obtains information regarding transmission target data (S401). For example, the control device 101 determines which service the data to be transmitted is related to, the priority of the service, the required throughput, the allowable delay, the allowable error rate, the allowable radio quality, etc. for the terminal devices belonging to the base station devices under its control. information. Then, the control device 101 executes initialization processing for radio resource allocation processing (S402). Here, the index when services are arranged in order of priority is i, and i=1 by initialization. Also, the estimated total interference amount is set to zero. Note that the priority used here can be determined based on, for example, the priority of the service and the amount of remaining time until the allowable delay is reached. For example, the shorter the time remaining until reaching the communication request delay for each service and the sooner the communication must be performed, the higher the priority is set here. Furthermore, the higher the priority of the service itself, the higher the priority is set here. Then, the control device 101 adds the amount of interference when a certain amount of radio resources are allocated to the service with the i-th highest priority to the estimated total amount of interference (S403), and the addition result is the interference amount of satellite communication. It is determined whether the amount exceeds the allowable amount (S404). The "certain amount" of radio resources here may be a relatively small amount of radio resources, such as 5% or 10% of the amount of total frequency resources available in the system, for example. However, without limitation, the "certain amount" of radio resources may be the total frequency resources available in the system or a portion thereof. Note that the "certain amount" may differ depending on the base station apparatus, for example. In this processing example, the amount of radio resource allocation is gradually increased, the amount of interference to satellite communication is estimated, and as many radio resources as possible are allocated within the allowable amount of interference. As a result, part or all of all frequency radio resources can be allocated to one service (terminal device) at once within the range of interference tolerance. By performing allocation based on such a small amount of radio resources, it becomes possible to allocate radio resources efficiently without waste. Further, the amount of interference when a certain amount of radio resources is allocated is estimated based on the certain amount, the distance between each base station device and a ground station for satellite communication, and the antenna characteristics of these devices.

If the control device 101 determines that the addition result calculated in S403 does not exceed the allowable amount of interference for satellite communication (NO in S404), the control device 101 controls the base station device that provides the i-th highest priority service by a certain amount. It is determined whether there is room to allocate wireless resources (S405). If the addition result calculated in S403 exceeds the interference tolerance (YES in S404), the control device 101 determines that if the addition result calculated in S403 exceeds the interference tolerance (YES in S404), the wireless resources are exhausted in the base station device that provides the i-th highest priority service, and a certain amount of radio resources are used up. If the wireless resource cannot be allocated (NO in S405), the process proceeds to S409 without allocating the wireless resource to the i-th highest priority service. If the control device 101 determines that there is room to allocate a certain amount of radio resources in the base station device that provides the i-th highest priority service (YES in S405), the control device 101 provides the i-th high priority service. A fixed amount of radio resources is allocated to the host (S406). The "fixed amount" here is the same as the "fixed amount" explained regarding S403. Then, the control device 101 uses the addition result calculated in S403 as the total interference amount estimated value (S407). After that, the control device 101 determines whether it is necessary to further allocate radio resources (whether it is necessary to increase the amount of allocated resources) for the service with the i-th highest priority (S408). This determination is made, for example, by checking the data buffer in which data for the terminal device to which the service is provided is stored, and by checking whether data to which no radio resources are allocated remains in the data buffer. . If radio resources have been allocated to any of the transmission data for the terminal device, it is determined that no further allocation of radio resources is necessary. On the other hand, if radio resources are not allocated to any of the transmission data for the terminal device, it is determined that further radio resource allocation is necessary. If the control device 101 determines that it is necessary to further allocate radio resources to the service with the i-th highest priority (YES in S408), the control device 101 returns the process to S403. On the other hand, if the control device 101 determines that there is no need to further allocate radio resources to the service with the i-th highest priority (NO in S408), the control device 101 advances the process to S409.

The control device 101 increments i in S409, and then determines whether the incremented i exceeds the number of all services (imax) (S410), and if it does (YES in S410), ends the process. do. On the other hand, if the control device 101 determines that the incremented i does not exceed imax (NO in S410), the control device 101 returns the process to S403 and executes the process of allocating wireless resources to the next highest priority service. do. This allows wireless resources to be allocated preferentially to services with high priority, and it is possible to prevent interference that exceeds the interference tolerance of satellite communication from occurring due to the communication.

Next, an example of allocating radio resources based on the allowable delay will be described using FIG. 5. FIG. 5 shows an example where five base station devices are controlled by the control device 101. In FIG. 5, "interference" is defined as "interference" when the ground station of the satellite communication system 121. Note that this value is a rough value and corresponds to the received power at the ground station 121, for example. “User (allowable delay)” indicates A to I that identify the user and the size of each allowable delay. For example, the allowable delay for user A is 4 subframes, and the allowable delay for users B and C is 8 subframes.

Here, it is assumed that the interference tolerance at the ground station 121 is "8". Here, the interference caused by the base station apparatus 2 and the base station apparatus 3 is "3", and the interference caused by the base station apparatus 4 and the base station apparatus 5 is "2". Therefore, radio resources can be allocated to these base station devices in the same subframe. In the example of FIG. 5, radio resources are allocated to base station device 2, base station device 3, and base station device 4 in subframes 0 and 6. On the other hand, the interference caused by the base station device 1 is "8". Therefore, in a subframe in which radio resources are allocated to any user of the base station device 1, the interference tolerance amount is reached at that point. In the example of FIG. 5, radio resources are allocated only to the base station device 1 in subframes 1, 3, 5, etc. Here, an allowable delay is set for each terminal device (user) connected to each base station device. Therefore, the control device 101 allocates radio resources so that these users satisfy the allowable delay. For example, since user A of base station device 1 has an allowable delay of 4, the radio resource allocation interval is set to be within 4 subframes. Therefore, after radio resources are allocated to user A in subframe 1, radio resources are allocated to user A in subframes 5, 9, and so on. Similarly, user B is assigned radio resources in subframe 3, subframe 11, etc., and user C is assigned radio resources in subframe 7, and then radio resources are assigned in subframe 15 (not shown). can be assigned. Note that if data for the user is prepared early and there is free radio resources, the next radio resource may be assigned without waiting for the fourth subframe after the radio resources are assigned.

For example, assume that user I has an allowable delay of 7 and that data is generated every 7 subframes. In this case, for example, after radio resources are assigned to user I in subframe 2, radio resources need to be assigned to user I in subframe 9. On the other hand, subframe 9 is allocated to user A of base station device 1, and the amount of interference is 8, which is the same as the allowable amount of interference. In such a case, interference may be reduced by, for example, reducing frequency resources, power resources, etc. of the radio resources allocated to at least one of user A and user I. . For example, in the base station device 1, it is assumed that by reducing the frequency resources used to 3/4, the amount of interference will be reduced from 8 to 6. Thereby, even when radio resources are allocated to user I, the total amount of interference can be kept within the range of allowable interference amount.

As shown in FIG. 5, radio resources can be allocated in consideration of the allowable delay.

Note that the amount of wireless resources used in each service may vary depending on the wireless environment of the terminal device, so each of the above processes is repeatedly executed at a predetermined period to perform appropriate control according to the situation. can be executed. Although control accuracy can be improved by shortening this cycle, if this process is frequently repeated in a situation where there are no major changes in the wireless environment, calculation resources may be wasted. Therefore, changes in the wireless environment of terminal devices connected to each base station device are monitored, and if there is no major change in the wireless environment for a certain period of time, at least the amount of radio resources required for that terminal device is The period of processing such as identification may be extended.

As described above, the dynamic radio resource allocation technology according to the present embodiment allows base station devices that were previously unable to use radio resources to use the radio resources. Furthermore, in base station apparatuses that conventionally had limitations on transmission power, for example, those limitations can now be removed or relaxed. Thereby, the frequency usage efficiency of the entire system can be improved while suppressing the influence on the system on the interfered side.

The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, to set out the scope of the invention, the following claims are hereby appended.

Claims (13)

For data to be transmitted in each of the plurality of base stations of the first wireless communication system, specifying means for specifying the amount of radio resources to be used for transmitting the data;
Based on the amount of the radio resources and the amount of interference with the communication of the second radio communication system by the radio waves when radio waves are transmitted using a predetermined amount of radio resources from each of the plurality of base stations, Allocation means for dynamically allocating radio resources for signal transmission in each of the plurality of base stations within a range that does not exceed an interference tolerance to a second radio communication system;
has
The allocation means determines whether each of the services can be provided based on the priority of the service to be provided by each of the plurality of base stations and the amount of radio resources scheduled to be used for the service. A control device that dynamically allocates wireless resources to each of the plurality of base stations based on the determination . When a first service is to be newly provided in at least one of the plurality of base stations, the allocation means determines the priority of the first service and the amount of radio resources scheduled to be used. , determining whether to provide the first service based on the priority of the second service being executed and the amount of radio resources scheduled to be used. The control device according to item 1 . When a first service is to be newly provided in at least one of the plurality of base stations, the allocation means determines the priority of the first service and the amount of radio resources scheduled to be used. , determining whether to stop the second service based on the priority of the second service being executed and the amount of radio resources scheduled to be used. The control device according to item 1 or 2 . The control device obtains information regarding the first service from each of the plurality of base stations,
The information regarding the first service is information indicating the amount of radio resources to be used when performing communication regarding the service with the terminal to which the first service is to be provided, or information indicating the amount of the radio resources. The control device according to claim 2 or 3 , characterized in that the control device includes information that can be estimated. The control device obtains information regarding the second service from each of the plurality of base stations,
The information regarding the second service may include information indicating the amount of radio resources to be used when performing communication regarding the service with a terminal to which the second service is provided, or information indicating the amount of radio resources. The control device according to any one of claims 2 to 4 , characterized in that the control device includes identifiable information. 6. The control device according to claim 4 , wherein the information regarding the acquired service further includes information that can specify the priority of the service. A claim characterized in that the information capable of estimating the amount of radio resources includes information on radio quality between the terminal and a base station that is scheduled to provide the first service to the terminal. The control device according to item 4 . 4. The radio quality information is obtained by establishing a radio resource control (RRC) connection between the terminal and a base station that provides the first service to the terminal. 7. The control device according to 7 . An RRC connection between the terminal and a base station scheduled to provide the first service to the terminal is established regardless of whether the terminal is provided with the first service. The control device according to claim 8 , characterized in that: 6. The information that can specify the amount of radio resources includes information on radio quality between the terminal and a base station that provides the second service to the terminal. Control device as described. The amount of interference depends on the distance between each of the plurality of base stations and a device of the second wireless communication system that receives interference from each of the plurality of base stations, the plurality of base stations and the device. , the transmission power density of radio waves per frequency in each of the plurality of base stations, and the amount of radio resources to be allocated. The control device according to any one of Items 1 to 10 . A control method executed by a control device, comprising:
For data to be transmitted in each of the plurality of base stations of the first wireless communication system, specifying the amount of radio resources to be used for transmitting the data;
Based on the amount of the radio resources and the amount of interference with the communication of the second radio communication system by the radio waves when radio waves are transmitted using a predetermined amount of radio resources from each of the plurality of base stations, Dynamically allocating radio resources for signal transmission in each of the plurality of base stations within a range that does not exceed an interference tolerance to a second radio communication system;
has
When dynamically allocating the radio resources, the service is allocated based on the priority of the service to be provided at each of the plurality of base stations and the amount of radio resources scheduled to be used for the service. A control method comprising : determining whether or not each of the plurality of base stations can be provided, and dynamically allocating radio resources to each of the plurality of base stations.
In the computer equipped with the control device,
For data to be transmitted in each of the plurality of base stations of the first wireless communication system, specify the amount of radio resources to be used for transmitting the data,
Based on the amount of the radio resources and the amount of interference with the communication of the second radio communication system by the radio waves when radio waves are transmitted using a predetermined amount of radio resources from each of the plurality of base stations, dynamically allocating radio resources for signal transmission in each of the plurality of base stations within a range that does not exceed an interference tolerance to a second radio communication system;
It is a program for
When dynamically allocating the radio resources, the service is allocated based on the priority of the service to be provided by each of the plurality of base stations and the amount of radio resources scheduled to be used for the service. A program characterized in that the program determines whether or not each of the plurality of base stations can be provided, and dynamically allocates radio resources to each of the plurality of base stations.

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