JP2020202487A - Base station device, communication method, and program - Google Patents

Abstract

To provide a technique that can realize the efficient use of radio resources.SOLUTION: A base station device capable of communicating with a user device with limited transmission/reception bandwidth includes: a resource monitoring unit that monitors utilization rates of an anchor carrier usable for transmission and reception of a common channel and user data, and a non-anchor carrier usable for transmission and reception of at least user data and determines whether the non-anchor carrier should be added or deleted based on monitoring results; and an identifying unit for identifying the non-anchor carrier to be added or deleted based on determination results.SELECTED DRAWING: Figure 3

Description

The present invention relates to base station devices, communication methods and programs.

In 3GPP (Third Generation Partnership Project), which is a standardization project for mobile communication systems, a power-saving wide area wireless network (LPWA: Low Power Wide Area) has already been standardized.

Non-Patent Document 1 describes NB-IoT (Narrow Band Internet of Things) and eMTC (enhanced Machine Type Communication) as LTE standards (hereinafter collectively referred to as LPWA standards) that realize cellular LPWA for IoT devices. Details regarding standardization are disclosed.

For example, in Release 13 of 3GPP, when the user device is an NB-IoT terminal, the transmission / reception bandwidth is limited to 1 PRB (Physical Resource Block). The user device is called a category NB1 user device.

The Mobile Broadband Standard, http://www.3gpp.org/news-events/3gpp-news/1805-iot_r14

By the way, the user apparatus of category NB1 transmits / receives user data using a frequency band of 1 PRB (hereinafter referred to as a carrier) designated by the base station. Since there are user devices other than category NB1 (for example, categories 2 to 5) such as smartphones and mobile Wifi routers in the wireless communication system, more carriers than necessary can be added to the user devices of category NB1. It is not desirable to occupy it. Therefore, it is desirable that the base station monitors the usage status (that is, the usage rate) of the radio resource and automatically controls the carrier assigned to each user device in the service area so that the radio resource can be used efficiently. , Such a technology does not yet exist.

The present invention has been made in view of the circumstances described above, and an object of the present invention is to provide a technique capable of realizing efficient use of wireless resources.

The base station apparatus according to one aspect of the present invention is a base station apparatus capable of communicating with a user apparatus having a limited transmission / reception bandwidth, and includes an anchor carrier that can be used for transmission / reception of a common channel and user data, and at least user data. Based on the monitoring results, the resource monitoring unit that monitors the usage rate with the non-anchor carriers that can be used for sending and receiving data, and the resource monitoring unit determines whether to add or remove non-anchor carriers. Based on this, it includes a specific part that identifies a non-anchor carrier to be added or deleted.

According to this aspect, the utilization rates of the anchor carriers and the non-anchor carriers are monitored, and the non-anchor carriers are added or deleted based on the monitoring result, so that the radio resources can be used efficiently.

The communication method according to one aspect of the present invention is a communication method implemented by a base station device capable of communicating with a user device having a limited transmission / reception bandwidth, and is an anchor carrier that can be used for transmission / reception of a common channel and user data. A resource monitoring step that monitors at least the usage rate with non-anchor carriers available for sending and receiving user data, and determines whether to add or remove non-anchor carriers based on the monitoring results, and resource monitoring. Includes a specific part that identifies non-anchor carriers to be added or removed based on the judgment results in the step.

A program according to an aspect of the present invention uses a computer constituting a base station device capable of communicating with a user device having a limited transmission / reception bandwidth, an anchor carrier that can be used for transmission / reception of a common channel and user data, and at least user data. Based on the monitoring results, the resource monitoring unit that monitors the usage rate with the non-anchor carriers that can be used for sending and receiving data, and the resource monitoring unit determines whether to add or remove non-anchor carriers. Based on this, the information that identifies the non-anchor carrier to be added or deleted is made to function as a notification unit that notifies the user device.

According to the present invention, it is possible to realize efficient use of wireless resources.

It is a schematic diagram which shows the structure of the wireless communication system which concerns on this embodiment. It is a figure which illustrated the operation form (downlink) of the user apparatus which supports category NB1. It is a block diagram which shows the functional structure of a base station apparatus. It is a figure which shows the flow of the resource monitoring process by a base station apparatus. It is a block diagram which shows the hardware composition of a base station apparatus.

Embodiments of the present invention will be described with reference to the accompanying drawings. In each figure, those having the same reference numerals have the same or similar configurations.

A. This Embodiment [System Configuration]
A configuration example of the wireless communication system according to the present embodiment will be described with reference to FIG. The wireless communication system 1 includes a base station device 10 and a user device 20. The wireless communication system 1 includes, but is not limited to, one base station device and one user device in this example. The wireless communication system 1 may include a plurality of base station devices and user devices. Further, it is assumed that the base station device 10 and the user device 20 each support category NB1. The user device 20 is called an NB-IoT terminal or the like, and supports a half-duplex (Half Duplex) communication method.

[Overview of Category NB1]
FIG. 2 is a diagram illustrating an operation mode (downlink) of the user device 20 that supports category NB1 defined by 3GPP.
FIG. 2 shows an operation mode within a system band (for example, 15 MHz) defined by LTE, and is also called in-band operation.

In the existing LTE, the radio resource is managed in the minimum block unit when allocating the PRB in LTE, which is called RBG (Resource Block Group). At present, as shown in FIG. 2, of the 75 PRBs, one specific PRB (PRB32 in RBG8 in FIG. 2) is assigned exclusively for NB-IoT. Not only the PRB32 in the RBG8 assigned exclusively for this NB-IoT, but also other PRB33, PRB34, PRB35 contained in the RBG8 cannot be used in LTE.

Based on such a situation, in the present embodiment, efficient use of wireless resources is realized while monitoring the usage status of RBG or the like to which each carrier assigned for NB-IoT belongs.

Here, the carriers defined in the category NB1 will be described.
Anchor carriers (Anchor Carriers) and non-anchor carriers (Non-Anchor Carriers) are set for NB-IoT of category NB1.

The anchor carrier is a carrier equivalent to a standby, and is a synchronization signal such as NPSS / NSSS (Narrowband Primary Synchronization Synchronization / Synchronization Synchronization Signal), SIB-NB (SymnrationBorn) information, which is broadcast information, and SIB-NB (System Information). It is a carrier that can be used to send and receive user data along with common channels such as channels, broadcast channels, and random access channels. The base station device 10 uses the broadcast information included in the anchor carrier to notify the user device 20 of information that identifies a non-anchor carrier that is currently available.

A non-anchor carrier is at least a carrier that can be used to send and receive user data. In 3GPP Release 13, only user data could be sent and received by non-anchor carriers. On the other hand, in the subsequent release 14 of 3GPP, user data can be sent and received by non-anchor carriers, some common channels (specifically, incoming information) can be notified, and a random access procedure (release). In 13, only the anchor carrier is supported) is possible. Therefore, in the user device 20 corresponding to release 13, the user device 20 corresponding to release 14 always waits on the anchor carrier and starts the random access sequence on the anchor carrier even when the connection is started. In, it has become possible to perform standby on a specific non-anchor carrier that can receive incoming call information and perform random access procedures. The specific non-anchor carrier means that the base station device 10 can receive incoming information and perform a random access procedure for the user device 20 corresponding to release 14 by using the broadcast information included in the anchor carrier. The non-anchor carrier when the anchor carrier is notified. For convenience of explanation, such a non-anchor carrier is referred to as a "standby non-anchor carrier".
As described above, in Release 14, although it is possible to notify some common channels by non-anchor carriers, the overhead is still small as compared with the anchor carriers that transmit and receive all common channels. Therefore, when setting a plurality of carriers, it is efficient to set one anchor carrier and additionally set a non-anchor carrier as needed.

The base station apparatus 10 sets a carrier for transmitting and receiving user data and the like by means of an RRC (Radio Resource Control) message for each user apparatus 20. Each user device 20 transmits / receives user data from the base station device 10 using any carrier (that is, an anchor carrier or a non-anchor carrier) set by an RRC message.

[Functional configuration]
Next, the functional configuration of the base station apparatus 10 will be described with reference to FIG. As shown in the figure, the base station apparatus 10 includes a storage unit 110, a transmission unit 111, a reception unit 112, a resource monitoring unit 113, and a specific unit 114. It should be noted that the figure merely shows the functional units particularly related to the embodiment of the present embodiment, and the base station apparatus 10 has, for example, other functional portions included in a general base station apparatus.

The storage unit 110 stores various data such as data set for the processing to be executed, data of the execution result, and data received by the base station apparatus 10.

The transmission unit 111 generates various signals of the physical layer from the signals of the upper layer to be transmitted from the base station apparatus 10, and wirelessly transmits them.
The receiving unit 112 receives various radio signals from the user device 20 and acquires a signal of a higher layer from the received signal of the physical layer.

The resource monitoring unit 113 monitors the usage rate of PRBs assigned as anchor carriers and non-anchor carriers (hereinafter referred to as “NB-IoT resource usage rate”), and adds non-anchor carriers based on the monitoring results. Make a decision to delete.

As an example, of the 75 PRBs in the system band shown in FIG. 2, one PRB (eg, PRB32) is set as the anchor carrier and two PRBs (eg, PRB33 and PRB35) are set as non-anchor carriers. However, the number is not limited to this, and the number of anchor carriers and non-anchor carriers can be arbitrarily set within a range not exceeding the number of PRBs in the system band. However, the amount of resources that can be allocated to the user device 20 is limited in the anchor carrier in which the common channel always exists, as compared with the non-anchor carrier in which some common channels may exist. Therefore, in the present embodiment, the addition or deletion is determined only for the non-anchor carrier.

The resource monitoring unit 113 is set with a resource upper limit value Tu1 (for example, X%), a resource lower limit value Tl1 (for example, Y%), and the like for determining the addition and deletion of non-anchor carriers. The resource lower limit value Tl1 is preferably set to, for example, 0% (Y = 0). When the resource usage rate of the NB-IoT to be monitored reaches the resource upper limit value Tu1, the resource monitoring unit 113 determines that a non-anchor carrier should be added. On the other hand, the resource monitoring unit 113 determines that the non-anchor carrier should be deleted when the resource usage rate of the NB-IoT to be monitored reaches the resource lower limit value Tl1.

When the resource monitoring unit 113 determines that a non-anchor carrier should be added or deleted, the identification unit 114 specifies a non-anchor carrier to be added or deleted based on the determination result. For example, when 0% is set as the resource lower limit value Tl1, the resource monitoring unit 113 detects that the usage rate of any of the non-anchor carriers has reached the resource lower limit value Tl1 (here, 0%). Then, the specific unit 114 specifies a non-anchor carrier (for example, PRB33) whose resource usage rate is actually 0% as a non-anchor carrier to be deleted. On the other hand, when the resource monitoring unit 113 detects that the usage rate of any of the non-anchor carriers has reached the resource upper limit value Tu1, the specific unit 114 determines the overall resource usage efficiency (LTE communication traffic, etc.). In consideration of the above, identify the non-anchor carrier to be added so as to maximize the utilization efficiency.

When the non-anchor carrier to be added or deleted is specified by the specific unit 114, the base station device 10 adds or deletes the non-anchor carrier and uses the anchor carrier for the user device 20 corresponding to the release 14. The notification information regarding the standby non-anchor carrier that is being notified is changed.
Here, the user device 20 corresponding to Release 13 ignores the broadcast information about the standby non-anchor carrier included in the anchor carrier because it is unknown information. In this case, the user device 20 corresponding to the release 13 always stands by at the anchor carrier.
On the other hand, the user device 20 corresponding to Release 14 receives all the broadcast information including the broadcast information about the non-anchor carrier that can be listened to, which is included in the anchor carrier, and then waits for the carrier from the anchor carrier. Change to anchor carry and start standby.

[Processing flow]
An example of the resource monitoring processing flow executed by the base station apparatus 10 will be described with reference to FIG. This process is controlled by the processor of the base station apparatus 10 executing a computer program stored in the storage unit. In the following description, it is assumed that one or more anchor carriers and one or more non-anchor carriers are set in the system band.

First, the base station apparatus 10 detects the resource usage rate of the NB-IoT to be monitored (step S1).
The base station apparatus 10 refers to the set resource upper limit value Tu1 and resource lower limit value Tl1 and the like, and determines whether or not to add or delete a non-anchor carrier (step S2).

<No addition or deletion of non-anchor carriers>
When the base station apparatus 10 determines that the non-anchor carrier should not be added or deleted (that is, the current status should be maintained), the process shown below is skipped and the process ends.

<Addition of non-anchor carriers>
When the base station apparatus 10 determines that a non-anchor carrier should be added because, for example, the usage rate of any of the non-anchor carriers has reached the resource upper limit value Tu1, the process proceeds to step S3 and the overall resource usage efficiency is increased. In consideration of (LTE communication traffic, etc.), identify the non-anchor carrier to be added, and add the non-anchor carrier. After that, for new calls, NB-IoT user data is transmitted and received using the added non-anchor carrier and the like.

<Delete non-anchor carrier>
When the base station apparatus 10 determines that the non-anchor carrier should be deleted because the usage rate of any of the non-anchor carriers has reached the resource lower limit value Tl1, the process proceeds to step S4 and the resource usage rate actually proceeds. A non-anchor carrier having a value of 0% (for example, PRB33) is specified as a non-anchor carrier to be deleted, and the non-anchor carrier is deleted. After that, for example, LTE user data is transmitted / received using the resources released by deleting the non-anchor carrier.

As described above, according to the present embodiment, the base station apparatus 10 monitors the resource usage rate of the NB-IoT, and adds or deletes non-anchor carriers based on the monitoring result, so that the radio resources are efficient. Can be used.

[Hardware configuration]
An example of the hardware configuration of the base station apparatus 10 will be described with reference to FIG. The function of the base station apparatus 10 described above is realized by, for example, the hardware configuration shown in the figure.

In the following description, the word "device" can be read as a circuit, device, unit, or the like. The hardware configuration of the base station device 10 may be configured to include one or more of the devices shown in FIG. 5, or may be configured not to include some of the devices.

As shown in FIG. 5, the base station device 10 includes a processor 11, a memory 12, a storage device 13, a communication device 14, an input device 15, and an output device 16.

The processor 11 controls the entire processing by the base station apparatus 10. The processor 11 includes, for example, a CPU (Central Processing Unit), a microprocessor, a digital signal processor (DSP: Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic), a PLC (Programmable Logic), and a PLD (Programmable Logic). It may be configured to include hardware such as Array).

The memory 12 is a computer-readable recording medium, and is, for example, a ROM (Read Only Memory), an EPROM (Erasable Program ROM), an EEPROM (Electrically Erasable Program ROM), a RAM (Random Access Memory), or a RAM (Random Access Memory). May be done. The memory 12 stores a computer program, a software module, and the like that can execute the processing by the base station apparatus 10 in the above embodiment.

The storage device 13 is a computer-readable recording medium, and may be composed of at least one such as a hard disk drive, a flexible disk, a digital versatile disk, a smart card, a flash memory, and a magnetic strip.

The communication device 14 is a device for performing communication between computers via a wireless communication network. The communication device 14 is also referred to as, for example, a network device, a network controller, a network card, or a communication module.

The input device 15 is a device (for example, a switch, a button, a sensor, etc.) that receives an input from the outside. The output device 16 is a device (for example, a display, a speaker, an LED lamp, etc.) that outputs to the outside.

Further, each device such as the processor 11 and the memory 12 is connected by a bus for communicating information. The bus may be composed of a single bus, or may be composed of different buses between devices.

B. Modifications The embodiments described above are for facilitating the understanding of the present invention, and are not for limiting the interpretation of the present invention. Each element included in the embodiment and its arrangement, material, condition, shape, size, etc. are not limited to those exemplified, and can be changed as appropriate.

In the present embodiment, the operation of the downlink of the user device 20 that supports the category NB1 is illustrated with reference to FIG. 2, but the purpose is not limited to this, and it can be applied to the operation of the uplink.

Further, in the present embodiment, the in-band operation has been described as an example, but the operation within the dedicated frequency band for NB-IoT (so-called stand-alone operation) and the LTE guard band have been described. It is also applicable to the operation in (so-called guard band operation).

1 ... wireless communication system, 10 ... base station device, 20 ... user device

Claims (6)

A base station device that can communicate with a user device with limited transmit / receive bandwidth.
Monitor the usage rate of the anchor carrier that can be used to send and receive common channels and user data, and at least the non-anchor carrier that can be used to send and receive user data, and add or delete the non-anchor carrier based on the monitoring result. The resource monitoring department that decides whether or not to do it,
A base station apparatus including a specific unit that identifies a non-anchor carrier to be added or deleted based on a determination result by the resource monitoring unit. The base station apparatus according to claim 1, wherein a resource upper limit value and a resource lower limit value for determining addition and deletion of the non-anchor carrier are set in the resource monitoring unit. The base station device according to claim 1 or 2, wherein the user device having a limited transmission / reception bandwidth is an NB-IoT (Narrow Band Internet of Things) terminal. The base station apparatus according to any one of claims 1 to 3, wherein the non-anchor carrier is a carrier that can be used for transmitting and receiving incoming information and user data that are a part of a common channel. A communication method implemented by a base station device capable of communicating with a user device having a limited transmission / reception bandwidth.
Monitor the usage rate of the anchor carrier that can be used to send and receive common channels and user data, and at least the non-anchor carrier that can be used to send and receive user data, and add or delete the non-anchor carrier based on the monitoring result. Resource monitoring steps to decide whether or not to do
A communication method including the specific step of identifying the non-anchor carrier to be added or deleted based on the determination result in the resource monitoring step. Computers that make up a base station device that can communicate with user devices with limited transmit / receive bandwidth
Monitor the usage rate of the anchor carrier that can be used to send and receive common channels and user data, and at least the non-anchor carrier that is used to send and receive user data, and add or delete the non-anchor carrier based on the monitoring result. The resource monitoring department that decides whether or not to do it,
A program for functioning as a specific unit for specifying the non-anchor carrier to be added or deleted based on the determination result by the resource monitoring unit.

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