WO2018127980A1 - Base station, terminal, wireless communication system, and wireless communication method - Google Patents

Abstract

Provided is a wireless communication system which includes a base station and a terminal that communicate using one system band. A base station includes a wireless line control unit that allocates, in the system band, a P-SCG and an S-SCG which have different system information. The wireless line control unit includes a P-SCG control unit and an S-SCG control unit. On the basis of the P-SCG system information, the P-SCG control unit carries out setting of a first wireless line between itself and the terminal. At such time, the P-SCG control unit notifies the terminal of the S-SCG system information. On the basis of the system information notified to the terminal, the S-SCG control unit carries out setting of a second wireless line between itself and the terminal.

Description

Base station, terminal, radio communication system and radio communication method

The present invention relates to a base station, a terminal, a wireless communication system, and a wireless communication method.

A wireless communication system using OFDM (Orthogonal Frequency Division Multiplexing) is known. In a wireless communication system using OFDM, when a terminal selects a cell in which a base station is defined, the terminal performs a random access procedure (wireless channel setting) on the base station using system information. As a result, a radio link between the base station and the terminal is established by random access.

In a radio communication system using OFDM, a system band is divided into a plurality of frequency bands, and radio resources are allocated to each frequency band. The system band is one frequency band constituting the wireless communication system. The system information includes radio resources, subcarrier intervals, symbol lengths, subframe lengths, and the like. When OFDM is used, the number of subcarriers, subcarrier interval, TTI (Transmission Time Interval), and number of symbols are the same in each frequency band. In each frequency band, the symbol length, slot length, subframe length, and frame length are the same. Therefore, when OFDM is used, waveform shaping (filtering) is performed on the entire system band.

As described above, in a wireless communication system using OFDM, system information is the same within a system band. For this reason, the terminal performs radio communication with the base station using the same system information notified in advance.

Special table 2011-514774 gazette International Publication No. 2009/131225

In recent years, wireless communication systems using F-OFDM (Filtered-Orthogonal Frequency Division Multiplexing) have been studied.

In a wireless communication system using F-OFDM, the system band is divided into a plurality of frequency bands within the same system band. Further, each frequency band is divided into a plurality of subcarrier groups (hereinafter referred to as SCG), and radio resources are allocated to each SCG. The system band is one frequency band constituting the wireless communication system. SCG may also be referred to as a cluster or a subcarrier block (SCB). When F-OFDM is used, each SCG is composed of a plurality of subcarriers, and at least one of the number of subcarriers, subcarrier spacing, TTI, symbol length, etc. is different in each SCG. Therefore, when F-OFDM is used, waveform shaping (filtering) is performed for each SCG.

As described above, in a wireless communication system using F-OFDM, system information differs for each SCG. The terminal does not grasp system information that differs for each SCG. For this reason, the terminal cannot perform wireless communication with the base station using system information that differs for each SCG.

The technology disclosed in the present application performs wireless communication between a terminal and a base station using system information that differs for each SCG.

In one aspect, the wireless communication system includes a base station and a terminal that communicate using one system band. The base station includes a radio network controller, a first controller, and a second controller. The radio network controller allocates first and second subcarrier groups (hereinafter referred to as SCG) having different system information within the system band. The first control unit sets the first radio channel with the terminal based on the first system information that is the system information of the first SCG, and the first controller that is the system information of the second SCG. 2 notifies the terminal of the system information. The second control unit sets a second wireless line with the terminal based on the second system information notified to the terminal.

In one aspect, the terminal and the base station can perform wireless communication using different system information for each SCG.

FIG. 1 is a diagram illustrating an example of a wireless communication system. FIG. 2 is a diagram illustrating an example of a terminal when OFDM is used. FIG. 3 is a diagram illustrating an example of a base station when OFDM is used. FIG. 4 is a diagram illustrating an example of a received signal processing unit when OFDM is used. FIG. 5 is a diagram illustrating an example of a transmission signal processing unit when OFDM is used. FIG. 6 is a diagram illustrating an example of a system band when OFDM is used. FIG. 7 is a diagram illustrating an example of a system band when F-OFDM is used in the wireless communication system according to the first embodiment. FIG. 8 is a diagram illustrating an example of each SCG when F-OFDM is used in the wireless communication system according to the first embodiment. FIG. 9 is a diagram illustrating an example of a communication service in the wireless communication system according to the first embodiment. FIG. 10 is a diagram illustrating an example of a terminal when F-OFDM is used in the wireless communication system according to the first embodiment. FIG. 11 is a diagram illustrating an example of a base station when F-OFDM is used in the wireless communication system according to the first embodiment. FIG. 12 is a diagram illustrating an example of a received signal processing unit when F-OFDM is used in the wireless communication system according to the first embodiment. FIG. 13 is a diagram illustrating an example of a transmission signal processing unit when F-OFDM is used in the wireless communication system according to the first embodiment. FIG. 14 is a diagram illustrating an example of a system information storage unit when F-OFDM is used in the wireless communication system according to the first embodiment. FIG. 15 is a diagram illustrating an example of a radio network controller when F-OFDM is used in the radio communication system according to the first embodiment. FIG. 16 is a sequence illustrating an example of the SCG selection setting process as the operation of the wireless communication system according to the first embodiment. FIG. 17 is a sequence illustrating an example of the SCG selection setting process as the operation of the wireless communication system according to the first embodiment. FIG. 18 is a sequence illustrating an example of the SCG selection setting process as the operation of the wireless communication system according to the first embodiment. FIG. 19 is a sequence illustrating an example of the SCG change process as the operation of the wireless communication system according to the second embodiment. FIG. 20 is a sequence illustrating an example of the SCG change process as the operation of the wireless communication system according to the second embodiment. FIG. 21 is a sequence illustrating an example of the SCG change process as the operation of the wireless communication system according to the second embodiment. FIG. 22 is a diagram illustrating an example of a radio channel controller of the base station when F-OFDM is used in the radio communication system according to the second embodiment. FIG. 23 is a sequence illustrating an example of the SCG change process as the operation of the wireless communication system according to the second embodiment. FIG. 24 is a sequence illustrating an example of the SCG change process as the operation of the wireless communication system according to the second embodiment. FIG. 25 is a sequence illustrating an example of the SCG change process as the operation of the wireless communication system according to the second embodiment. FIG. 26 is a sequence illustrating an example of the SCG change process as the operation of the wireless communication system according to the second embodiment. FIG. 27 is a flowchart illustrating an example of the SCG deletion process as the operation of the wireless communication system according to the second embodiment. FIG. 28 is a diagram illustrating an example of a hardware configuration of the base station. FIG. 29 is a diagram illustrating an example of a hardware configuration of the terminal.

Hereinafter, embodiments of a base station, a terminal, a wireless communication system, and a wireless communication method disclosed in the present application will be described in detail based on the drawings. The following examples do not limit the disclosed technology.

In the wireless communication system according to the embodiment, F-OFDM (Filtered-Orthogonal Frequency Division Multiplexing) is used as a transmission format. Here, in order to explain the difference between a radio communication system using F-OFDM and a radio communication system using OFDM, first, a radio communication system using OFDM will be described. Thereafter, a wireless communication system using F-OFDM will be described as an embodiment.

[1. Wireless communication system using OFDM]
FIG. 1 is a diagram illustrating an example of a wireless communication system. The wireless communication system includes a base station 100 and a terminal 200.

Base station 100 and terminal 200 perform wireless communication. Above the base station 100, for example, an MME (Mobility Management Entity) 41, an SGW (Serving Gateway) 42, and a PGW (Packet data network Gateway) 43 in LTE (Long Term Evolution) are provided. The MME 41 is a gateway that performs network control. The SGW 42 is a gateway that handles user data. The PGW 43 is a gateway for connecting to an external Internet or the like.

The terminal 200 is, for example, a UE (User Equipment) in LTE. The base station 100 is, for example, an eNB (evolved Node B) in LTE. In the 3GPP (3rd Generation Partnership Project), the fifth generation mobile communication system (5G) is being studied. In 5G, adoption of New RAT (Radio Access Technology) as a new communication technology is being studied. In New RAT, eNB is called 5GNB (5G base station) or gNB.

[1.1 Terminal configuration when using OFDM]
FIG. 2 is a diagram illustrating an example of a terminal 200 when OFDM is used. The terminal 200 includes an antenna 201, a reception radio unit 202, a reception signal processing unit 203, a control signal extraction unit 204, a radio channel quality measurement unit 205, a radio channel control unit 206, a control signal generation unit 207, a buffer 208, and a transmission signal processing unit. 209 and a transmission radio unit 210. The terminal 200 also includes a subcarrier generation unit 211 and a system information storage unit 212.

The reception radio unit 202 operates under the control (dotted line in FIG. 2) from the radio line control unit 206. The reception radio unit 202 receives a signal transmitted from the base station 100 via the antenna 201. Reception radio section 202 amplifies the received signal and frequency-converts the amplified signal into a baseband signal. Then, reception radio section 202 outputs the frequency-converted signal to reception signal processing section 203.

The reception signal processing unit 203 operates under the control (dotted line in FIG. 2) from the wireless line control unit 206. The reception signal processing unit 203 receives the signal output from the reception radio unit 202.

FIG. 4 is a diagram illustrating an example of a received signal processing unit when OFDM is used. When OFDM is used, the received signal processing unit 203 includes an ADC (Analog to Digital Converter) 301, a CP (Cyclic Prefix) removal unit 302, an FFT (Fast Fourier Transform) unit 303, and a demodulation / decoding unit 304. The CP is generally called a GI (Guard Interval) or a redundant part.

The ADC 301 converts the signal output from the reception wireless unit 202 into a digital signal. Then, the ADC 301 outputs the converted digital signal to the CP removal unit 302.

The CP removing unit 302 removes a CP (Cyclic Prefix) from the digital signal output from the ADC 301. Then, CP removing section 302 outputs the signal from which CP has been removed to FFT section 303.

The FFT unit 303 performs FFT on the signal output from the CP removal unit 302. As a result, the signal output from the CP removing unit 302 is converted from a time domain signal to a frequency domain signal. FFT section 303 outputs the signal subjected to the FFT to demodulation / decoding section 304.

The demodulation / decoding unit 304 demodulates the signal output from the FFT unit 303. Then, the demodulator / decoder 304 decodes the demodulated signal. Demodulation / decoding section 304 outputs the decoded signal.

The signal output from the received signal processing unit 203 includes a control signal, a data signal, a pilot signal, and the like. The pilot signal is, for example, a signal such as a reference signal in LTE. The control signal is a signal related to data transmission. The control signal and the data signal are transmitted from the received signal processing unit 203 to the upper level. Here, the upper level corresponds to, for example, a MAC (Media Access Control) in LTE.

2, the control signal extraction unit 204 extracts a control signal from the signal output from the reception signal processing unit 203. The control signal extraction unit 204 outputs the extracted control signal to the radio channel control unit 206.

Radio channel quality measuring section 205 extracts a pilot signal from the signal output from received signal processing section 203, and measures the radio channel quality based on the extracted pilot signal. The radio channel quality represents at least one of reception power and reception quality. The received power is, for example, reference signal received power (RSRP: Reference Signal Received Power) in LTE. The reception quality is, for example, a reference signal reception quality (RSRQ) in LTE. The radio channel quality measurement unit 205 outputs the measured radio channel quality to the radio channel control unit 206 as downlink radio channel quality information. In LTE, it is called a reference signal, but is generally called a pilot.

The radio network controller 206 extracts a control signal from the signal output from the control signal extractor 204, and performs RRC (Radio Resource Control) layer processing based on the extracted control signal. That is, radio resource control is performed. Radio channel control section 206 outputs downlink radio channel quality information output from radio channel quality measurement section 205 to control signal generation section 207. RRC is also called radio resource control or radio channel control.

The control signal generator 207 generates a control signal based on the downlink radio channel quality information output from the radio channel controller 206. Then, the control signal generation unit 207 outputs the generated control signal to the transmission signal processing unit 209.

The buffer 208 outputs a data signal from the host to the transmission signal processing unit 209 under the control of the wireless line control unit 206 (dotted line in FIG. 2).

The subcarrier generation unit 211 operates by control from the wireless line control unit 206 (dotted line in FIG. 2). The subcarrier generation unit 211 generates subcarriers and outputs them to the transmission signal processing unit 209.

The transmission signal processing unit 209 operates under the control (dotted line in FIG. 2) from the wireless line control unit 206. The transmission signal processing unit 209 receives the data signal output from the buffer 208, the control signal output from the control signal generation unit 207, and the subcarrier output from the subcarrier generation unit 211.

FIG. 5 is a diagram illustrating an example of a transmission signal processing unit when OFDM is used. When OFDM is used, the transmission signal processing unit 209 includes an encoding / modulation unit 401, a subcarrier mapping unit 402, and an IFFT (Inverse Fast Fourier Transform) unit 403. The transmission signal processing unit 209 further includes a CP adding unit 404 and a DAC (Digital to Analog Converter) 405.

The encoding / modulation unit 401 encodes the data signal output from the buffer 208 and the control signal output from the control signal generation unit 207. The encoding / modulating unit 401 modulates the encoded signal. Encoding / modulating section 401 outputs the modulated signal to subcarrier mapping section 402.

The subcarrier mapping unit 402 receives the signal output from the encoding / modulation unit 401 and the subcarrier output from the subcarrier generation unit 211. Then, subcarrier mapping section 402 maps the modulation symbol of the signal modulated by encoding / modulating section 401 to the subcarrier. Subcarrier mapping section 402 outputs the mapped signal to IFFT section 403.

The IFFT unit 403 receives the signal output from the subcarrier mapping unit 402. Then, IFFT section 403 performs IFFT on the modulation symbol of the signal mapped by subcarrier mapping section 402. As a result, the symbol of the signal output from subcarrier mapping section 402 is converted from a modulation symbol in the frequency domain to an effective symbol in the time domain. IFFT section 403 outputs the signal subjected to IFFT to CP adding section 404.

CP adding section 404 generates an OFDM symbol by adding a CP (Cyclic Prefix) to the signal output from IFFT section 403. CP adding section 404 converts the generated OFDM symbol into a predetermined radio frequency. Then, CP adding section 404 outputs the converted signal to DAC 405.

The DAC 405 converts the signal output from the CP adding unit 404 into an analog signal. Then, the DAC 405 outputs the converted analog signal to the transmission radio unit 210.

2, the transmission radio unit 210 operates under the control (dotted line in FIG. 2) from the radio line control unit 206. Transmission radio section 210 transmits the signal output from transmission signal processing section 209 from antenna 201.

The system information storage unit 212 stores the system information notified to the terminal 200. System information will be described later.

[1.2 Configuration of base station when using OFDM]
FIG. 3 is a diagram illustrating an example of the base station 100 when OFDM is used. Base station 100 includes antenna 101, reception radio section 102, reception signal processing section 103, control signal extraction section 104, radio channel quality measurement section 105, radio channel control section 106, control signal generation section 107, buffer 108, transmission signal processing. Unit 109 and transmission radio unit 110. In addition, the base station 100 includes a subcarrier generation unit 111 and a system information storage unit 112.

The reception radio unit 102 operates under the control (dotted line in FIG. 3) from the radio line control unit 106. Reception radio section 102 receives a signal transmitted from terminal 200 via antenna 101. Then, the reception radio unit 102 amplifies the received signal and frequency-converts the amplified signal into a baseband signal. Reception radio section 102 outputs the frequency-converted signal to reception signal processing section 103.

The received signal processing unit 103 operates under the control (dotted line in FIG. 3) from the wireless line control unit 106. Reception signal processing section 103 demodulates the signal output from reception radio section 102 and decodes the demodulated signal. Here, the configuration of the received signal processing section 103 of the base station 100 is the same as the configuration of the received signal processing section 203 of the terminal 200, and therefore detailed description thereof is omitted. Reception signal processing section 103 outputs the decoded signal to control signal extraction section 104 and radio channel quality measurement section 105.

The signal output from the received signal processing unit 103 includes a control signal and individual data (Dedicated data). The control signal includes at least one of individual control information (Dedicated control information) and common control information (Common control information). The individual data represents a data signal of the terminal 200. Control signals and individual data are transmitted from the received signal processing unit 103 to the upper level. Here, the upper level corresponds to the MAC in LTE, for example.

The control signal extraction unit 104 extracts a control signal from the signal output from the reception signal processing unit 103. The control signal extraction unit 104 outputs the extracted control signal to the radio channel control unit 106.

The radio channel quality measurement unit 105 measures the radio channel quality based on the signal output from the received signal processing unit 103. Radio channel quality measurement section 105 then outputs the measured radio channel quality to radio channel control section 106 as uplink radio channel quality information.

The radio network controller 106 performs RRC layer processing based on the control signal output from the control signal extractor 104. That is, radio resource control is performed.

Further, the radio channel control unit 106, based on the downlink radio channel quality information included in the control signal output from the control signal extraction unit 104 and the uplink radio channel quality information output from the radio channel quality measurement unit 105, The scheduling described later is performed. Radio channel controller 106 outputs the scheduling result to control signal generator 107.

The control signal generation unit 107 generates a control signal based on the scheduling result output from the wireless line control unit 106. Then, the control signal generation unit 107 outputs the generated control signal to the transmission signal processing unit 109.

The buffer 108 outputs a data signal from the host to the transmission signal processing unit 109 under the control of the wireless line control unit 106 (dotted line in FIG. 3).

The subcarrier generation unit 111 operates under the control from the wireless line control unit 106 (dotted line in FIG. 3). The subcarrier generation unit 111 generates a subcarrier and outputs it to the transmission signal processing unit 109.

The transmission signal processing unit 109 operates under the control from the wireless line control unit 106 (dotted line in FIG. 3). The transmission signal processing unit 109 encodes the data signal output from the buffer 108 and the control signal output from the control signal generation unit 107, and modulates the encoded signal. Transmission signal processing section 109 outputs the modulated signal to transmission radio section 110. Here, since the configuration of transmission signal processing section 109 of base station 100 is the same as the configuration of transmission signal processing section 209 of terminal 200, detailed description thereof is omitted.

The transmission wireless unit 110 operates under the control (dotted line in FIG. 3) from the wireless line control unit 106. Transmission radio section 110 transmits the signal output from transmission signal processing section 109 from antenna 101.

The system information storage unit 112 stores system information. System information will be described later.

[1.3 About scheduling]
The radio network controller 106 of the base station 100 performs scheduling.

For example, the radio channel controller 106 of the base station 100 selects the terminal 200 that performs downlink data transmission based on the downlink radio channel quality information included in the control signal output from the control signal extractor 104. Also, the radio channel controller 106 of the base station 100 selects the terminal 200 that permits uplink data transmission based on the uplink radio channel quality information output from the radio channel quality measurement unit 105.

Scheduling methods include a Max CIR method selected from a terminal 200 having a high CIR (Carrier to Interference Ratio), and a proportional fairness method that assigns radio resources fairly to each terminal 200 based on radio channel quality. Further, as a scheduling method, there is a round robin method in which radio resources are evenly allocated to all terminals 200.

The radio network controller 106 of the base station 100 selects radio resources, modulation schemes, and coding rates to be used when transmitting data to the selected terminal 200. Radio channel control section 106 outputs the selected radio resource, modulation scheme and coding rate to control signal generation section 107 as a result of scheduling. The control signal generation unit 107 generates the radio resource, modulation scheme, and coding rate output from the radio channel control unit 106 as a control signal related to data transmission. The control signal is notified from base station 100 to terminal 200.

[1.4 Establishing wireless connection (random access)]
For example, when the terminal 200 is turned on, when the user moves the terminal 200, or when the standby state becomes longer in the terminal 200, the terminal 200 performs cell selection or cell reselection. To do. The radio network controller 206 of the terminal 200 performs random access to the base station 100 using the system information notified in advance to the terminal 200 when the base station 100 selects a specified cell. Perform the procedure. As a result, the radio channel between the base station 100 and the terminal 200 is established by random access.

Random access is exemplified by contention-based random access (see TS36.300 for details) in which terminal 200 selects a random access preamble and notifies base station 100 based on system information on the premise of collision of preambles. The In this case, radio channel controller 206 of terminal 200 transmits a random access preamble, and radio channel controller 106 of base station 100 receives the random access preamble transmitted from terminal 200. At this time, the radio network controller 106 of the base station 100 generates a response signal for the random access preamble. The radio network controller 106 of the base station 100 transmits the generated response signal to the terminal 200. As a result, the radio channel between the base station 100 and the terminal 200 is established by random access.

Also, random access is performed when performing handover to another frequency or another base station. In this case, examples of random access include non-contention based random access (see TS36.300) in which a random access preamble to be used is given from the base station 100 to the terminal 200 in advance. In this case, the radio network controller 106 of the base station 100 notifies the terminal 200 of the random access preamble in advance. Radio channel controller 206 of terminal 200 transmits a random access preamble, and radio channel controller 106 of base station 100 receives the random access preamble transmitted from terminal 200. At this time, the radio network controller 106 of the base station 100 generates a response signal for the random access preamble. The radio network controller 106 transmits the generated response signal to the terminal 200. As a result, the radio channel between the base station 100 and the terminal 200 is established by random access.

[1.5 About handover]
For example, the radio channel controller 106 of the base station 100 compares the first radio channel quality when connected to the terminal 200 with the second radio channel quality from other adjacent base stations. As a result of the comparison, the second radio channel quality is better than the first radio channel quality due to the degradation of the first radio channel quality. In this case, the radio network controller 106 of the base station 100 selects another base station as the HO destination base station. Subsequently, the radio network controller 106 of the base station 100 transmits a HO request to the selected base station. When receiving the dedicated preamble for the HO request from the selected base station, the radio network controller 106 of the base station 100 notifies the terminal 200 of the received dedicated preamble as HO control information. The radio network controller 206 of the terminal 200 performs non-contention based random access using the dedicated preamble notified from the base station 100. Thereby, HO is implemented. That is, the base station that communicates with terminal 200 is switched from base station 100 to the selected base station.

[1.6 About system information]
FIG. 6 is a diagram illustrating an example of a system band when OFDM is used. In a radio communication system using OFDM, a system band is divided into a plurality of frequency bands, and radio resources are allocated to each frequency band. The system band is one frequency band constituting the wireless communication system. The system band is 20 MHz in LTE, for example. Each frequency band is, for example, an RB (Resource Block) in LTE.

In a radio communication system using OFDM, system information includes radio resources, subcarrier spacing, symbol length, subframe length, and the like. When OFDM is used, the number of subcarriers, subcarrier interval, TTI (Transmission Time Interval), and number of symbols are the same in each frequency band. In each frequency band, the symbol length, slot length, subframe length, and frame length are the same. Therefore, when OFDM is used, waveform shaping (filtering) is performed on the entire system band.

Thus, in a wireless communication system using OFDM, the system information is the same within the system band. For this reason, terminal 200 performs radio communication with base station 100 using the same system information notified in advance.

[2. Wireless communication system using F-OFDM (Example 1)]
Next, a radio communication system using F-OFDM will be described as the radio communication system according to the first embodiment. Here, in the first embodiment, the same description as the wireless communication system using OFDM is omitted.

[2.1 About system information]
FIG. 7 is a diagram illustrating an example of a system band when F-OFDM is used in the wireless communication system according to the first embodiment. In a wireless communication system using F-OFDM, the system band is divided into a plurality of frequency bands. Further, each frequency band is divided into a plurality of subcarrier groups (hereinafter referred to as SCG), and radio resources are allocated to each SCG. The system band is one frequency band constituting the wireless communication system. SCG may also be referred to as a cluster or a subcarrier block (SCB).

In a radio communication system using F-OFDM, the system information includes radio resources, subcarrier intervals, symbol lengths, subframe lengths, and the like, as in the radio communication system using OFDM.

FIG. 8 is a diagram illustrating an example of each SCG when F-OFDM is used in the wireless communication system according to the first embodiment. When F-OFDM is used, each SCG is composed of a plurality of subcarriers, and at least one of the number of subcarriers, subcarrier spacing, TTI, symbol length, etc. is different in each SCG. For example, as shown in FIG. 8, each of SCG1 to SCG3 has a different subcarrier interval and TTI. Therefore, when F-OFDM is used, waveform shaping (filtering) is performed for each SCG.

Thus, in a wireless communication system using F-OFDM, system information differs for each SCG. The terminal 200 does not grasp SCG system information. For this reason, terminal 200 cannot perform wireless communication with base station 100 using system information that differs for each SCG. Therefore, in a wireless communication system using F-OFDM, it is desirable to notify system information to terminal 200 for each SCG.

In the wireless communication system according to the first embodiment, a multiple access method (Multiple Access) for changing system information by changing a subcarrier interval and a symbol length for each SCG, such as UF (Universal-Filtered) -OFDM, is used. Including, it is generally called F-OFDM.

[2.2 Affinity between F-OFDM and RAN network slice]
FIG. 9 is a diagram illustrating an example of a communication service in the wireless communication system according to the first embodiment.

In the fifth generation mobile communication system (5G), an architecture of a network slice for allocating resources of a wired network and a wireless network according to a service that the terminal 200 wants to enjoy is being studied.

For example, a first RAN (Radio Access Network) network slice (hereinafter referred to as RNS) 20 and a plurality of second RNSs 21 to 24 are applied to the terminal 200 and the base station 100.

The first network slice (hereinafter referred to as NS) 30 and the second NS 31 to 34 are applied to the base station 100 and its upper level. For example, MME41, SGW42, PGW43, and core network in LTE are provided above the base station 100.

For example, the first RNS 20 and the first NS 30 are used for a basic service that realizes an existing function such as a broadband service.

For example, the second RNS 21 and the second NS 31 are used for a low-speed transmission service that transmits the output of the sensor at a low speed. The second RNS 22 and the second NS 32 are used for a high-speed transmission service that transmits a moving image or the like at a high speed. The second RNS 23 and the second NS 33 are used for a low-delay service that requires a low delay in in-vehicle communication. The second RNS 24 and the second NS 34 are used for high-quality and low-delay services that require high reliability when performing medical treatment or the like remotely.

Thus, a plurality of communication services are set based on uses such as low-speed transmission and high-speed transmission. For example, wireless communication is performed for a communication service that the user of terminal 200 intends to use among a plurality of communication services.

Meanwhile, radio resources used for each F-OFDM SCG are set based on traffic (communication amount), transmission delay, transmission speed, and the like. Thus, a plurality of SCGs in each frequency band in F-OFDM and a plurality of RNSs used for a plurality of communication services have high affinity. That is, in a wireless communication system using F-OFDM, a plurality of SCGs can be set corresponding to RNSs of a plurality of communication services, respectively.

For example, a plurality of SCGs are divided into P (Primary) -SCG 10 which is a first SCG and S (Secondary) -SCGs 11 to 14 which are a plurality of second SCGs. The P-SCG 10 corresponds to a center frequency bandwidth of 1.4 MHz in LTE, for example, and is also called T (Temporary) -SCG. In the following, one S-SCG may be provided unless otherwise noted.

In this case, the P-SCG 10 is set corresponding to the first RNS 20 and used for the basic service. The S-SCG 11 is set corresponding to the second RNS 21 and used for the low-speed transmission service. The S-SCG 12 is set corresponding to the second RNS 22 and is used for a high-speed transmission service. The S-SCG 13 is set corresponding to the second RNS 23 and is used for the low delay service. The S-SCG 14 is set corresponding to the second RNS 24 and is used for a high quality low delay service.

[2.3 Configuration of terminal when F-OFDM is used]
FIG. 10 is a diagram illustrating an example of a terminal 200 when F-OFDM is used in the wireless communication system according to the first embodiment. When F-OFDM is used, the terminal 200 includes a reception signal processing unit 203F, a radio channel control unit 206F, and a transmission signal processing unit 209F. A plurality of SCGs, that is, the P-SCG 10 and the S-SCGs 11 to 14 are assigned to the radio network controller 206F. The reception signal processing unit 203F, the radio line control unit 206F, and the transmission signal processing unit 209F will be described later. Similarly to the case of using OFDM, terminal 200 has antenna 201, reception radio section 202, control signal extraction section 204, radio channel quality measurement section 205, control signal generation section 207, buffer 208, transmission radio section 210, sub A carrier generation unit 211 and a system information storage unit 212 are included.

[2.4 Base station configuration when using F-OFDM]
FIG. 11 is a diagram illustrating an example of the base station 100 when F-OFDM is used in the wireless communication system according to the first embodiment. When F-OFDM is used, the base station 100 includes a reception signal processing unit 103F, a radio channel control unit 106F, a transmission signal processing unit 109F, and a system information storage unit 112F. A plurality of SCGs, that is, P-SCG 10 and S-SCGs 11 to 14 are assigned to the radio network controller 106F. The reception signal processing unit 103F, the radio line control unit 106F, the transmission signal processing unit 109F, and the system information storage unit 112F will be described later. Similarly to the case where OFDM is used, the base station 100 includes an antenna 101, a reception radio unit 102, a control signal extraction unit 104, a radio channel quality measurement unit 105, a control signal generation unit 107, a buffer 108, a transmission radio unit 110, A subcarrier generation unit 111 is included.

FIG. 12 is a diagram illustrating an example of a received signal processing unit when F-OFDM is used in the wireless communication system according to the first embodiment. When F-OFDM is used, the reception signal processing unit 103F of the base station 100 includes an ADC 301 and a plurality of reception signal processing systems 320 to 324. Each of the plurality of received signal processing systems 320 to 324 includes a CP removing unit 302, an FFT unit 303, a demodulation / decoding unit 304, and a filter 310. The ADC 301, the CP removing unit 302, the FFT unit 303, and the demodulation / decoding unit 304 have the same configuration as when OFDM is used.

The plurality of reception signal processing systems 320 to 324 are divided into a first reception signal processing system 320 and a plurality of second reception signal processing systems 321 to 324. In this case, the first received signal processing system 320 is provided corresponding to the P-SCG10. The plurality of second received signal processing systems 321 to 324 are provided corresponding to the plurality of S-SCGs 11 to 14, respectively.

The ADC 301 converts the signal output from the reception wireless unit 102 into a digital signal. Then, the ADC 301 outputs the converted digital signal to the plurality of received signal processing systems 320 to 324.

Each filter 310 of the plurality of received signal processing systems 320 to 324 passes a signal in a specific frequency band with respect to the signal output from the ADC 301, and attenuates signals in other frequency bands. The signal that has passed through the filter 310 is output to the CP removal unit 302.

The CP removing unit 302 removes the CP from the digital signal output from the ADC 301. Then, CP removing section 302 outputs the signal from which CP has been removed to FFT section 303.

The FFT unit 303 performs FFT on the signal output from the CP removal unit 302. As a result, the signal output from the CP removing unit 302 is converted from a time domain signal to a frequency domain signal. FFT section 303 outputs the signal subjected to the FFT to demodulation / decoding section 304.

The demodulation / decoding unit 304 demodulates the signal output from the FFT unit 303. Then, the demodulator / decoder 304 decodes the demodulated signal. Demodulation / decoding section 304 outputs the decoded signal to control signal extraction section 104 and radio channel quality measurement section 105.

In the case of the reception signal processing unit 203F of the terminal 200, it is sufficient that at least one reception signal processing system is provided.

FIG. 13 is a diagram illustrating an example of a transmission signal processing unit when F-OFDM is used in the wireless communication system according to the first embodiment. When F-OFDM is used, the transmission signal processing unit 109F of the base station 100 includes a plurality of transmission signal processing systems 420 to 424, a synthesis unit 411, and a DAC 405. Each of the plurality of transmission signal processing systems 420 to 424 includes an encoding / modulation unit 401, a subcarrier mapping unit 402, an IFFT unit 403, a CP adding unit 404, and a filter 410. Encoding / modulating section 401, subcarrier mapping section 402, IFFT section 403, CP adding section 404, and DAC 405 have the same configuration as when OFDM is used.

The plurality of transmission signal processing systems 420 to 424 are divided into a first transmission signal processing system 420 and a plurality of second transmission signal processing systems 421 to 424. In this case, the first transmission signal processing system 420 is provided corresponding to the P-SCG 10. The plurality of second transmission signal processing systems 421 to 424 are provided corresponding to the plurality of S-SCGs 11 to 14, respectively.

Each encoding / modulation unit 401 of the plurality of transmission signal processing systems 420 to 424 receives the data signal output from the buffer and the control signal output from the control signal generation unit 107. Here, the data signal received by the first transmission signal processing system 420 represents data related to a service applied to the first RNS 20. The data signals received by the plurality of second transmission signal processing systems 421 to 424 represent data related to services applied to the plurality of second RNS 21 to 24, respectively.

The encoding / modulation unit 401 encodes the data signal output from the buffer 108 and the control signal output from the control signal generation unit 107. The encoding / modulating unit 401 modulates the encoded signal. Encoding / modulating section 401 outputs the modulated signal to subcarrier mapping section 402.

The subcarrier mapping unit 402 receives the signal output from the encoding / modulation unit 401 and the subcarrier output from the subcarrier generation unit 111. Then, subcarrier mapping section 402 maps the modulation symbol of the signal modulated by encoding / modulating section 401 to the subcarrier. Subcarrier mapping section 402 outputs the mapped signal to IFFT section 403.

The IFFT unit 403 receives the signal output from the subcarrier mapping unit 402. Then, IFFT section 403 performs IFFT on the modulation symbol of the signal mapped by subcarrier mapping section 402. As a result, the symbol of the signal output from subcarrier mapping section 402 is converted from a modulation symbol in the frequency domain to an effective symbol in the time domain. IFFT section 403 outputs the signal subjected to IFFT to CP adding section 404.

CP adding section 404 generates an OFDM symbol by adding a CP to the signal output from IFFT section 403. CP adding section 404 converts the generated OFDM symbol into a predetermined radio frequency. Then, CP adding section 404 outputs the converted signal to filter 410.

The filter 410 allows a signal in a specific frequency band to pass through the signal output from the CP adding unit 404 and attenuates signals in other frequency bands. The signal that has passed through the filter 410 is output to the synthesis unit 411.

The combining unit 411 combines the signals output from the filters 410 of the plurality of transmission signal processing systems 420 to 424. The synthesized signal is output to the DAC 405.

The DAC 405 converts the signal output from the synthesis unit 411 into an analog signal. Then, the DAC 405 outputs the converted analog signal to the transmission radio unit 110.

In the case of the transmission signal processing unit 209F of the terminal 200, it is sufficient that at least one transmission signal processing system is provided.

FIG. 14 is a diagram illustrating an example of a system information storage unit when F-OFDM is used in the wireless communication system according to the first embodiment. The system information storage unit 112F of the base station 100 stores system information of different P-SCGs 10 and S-SCGs 11 to 14 in association with service types.

For example, the system information storage unit 112F stores the system information of the P-SCG 10 in association with the basic service described above. The system information storage unit 112F stores the system information of the S-SCG 11 in association with the above-described low-speed transmission service. The system information storage unit 112F stores the system information of the S-SCG 12 in association with the above-described high-speed transmission service. The system information storage unit 112F stores the system information of the S-SCG 13 in association with the above-described low delay service. The system information storage unit 112F stores the system information of the S-SCG 14 in association with the above-described high quality low delay service.

FIG. 15 is a diagram illustrating an example of a radio network controller when F-OFDM is used in the radio communication system according to the first embodiment. The radio network controller 106F of the base station 100 has a plurality of controllers. The plurality of control units are provided for a plurality of SCGs assigned to each frequency band in the system band. Here, the first control unit among the plurality of control units is referred to as a P (Primary) -SCG control unit 610, and the second control unit is referred to as an S (Secondary) -SCG control unit 620. The S-SCG control unit 620 includes S-SCG control units 611 to 614.

The P-SCG control unit 610 is provided for the P-SCG 10 used for basic services. The S-SCG control unit 611 is provided for the S-SCG 11 used for the low-speed transmission service. The S-SCG control unit 612 is provided for the S-SCG 12 used for the high-speed transmission service. The S-SCG control unit 613 is provided for the S-SCG 13 used for the low delay service. The S-SCG control unit 614 is provided for the S-SCG 14 used for the high quality and low delay service.

[2.5 Operation of Wireless Communication System According to First Embodiment]
[2.5.1 SCG selection setting process (part 1)]
FIG. 16 is a sequence illustrating an example of the SCG selection setting process as the operation of the wireless communication system according to the first embodiment.

First, the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 notifies the terminal 200 of system information of the entire system band (step S100). The system information of the entire system band is, for example, MIB (Master Information Block) or SIB (System Information Block) in 3GPP. The system information includes information indicating cell priority, information for cell selection, information for random access, and the like in addition to control information such as radio resources, subcarrier intervals, symbol lengths, and subframe lengths. Although not specifically shown here, the information included in the MIB or the SIB described in the W-CDMA specification or LTE specification defined in 3GPP may be included.

The radio channel control unit 206F of the terminal 200 controls the reception radio unit 202 and the reception signal processing unit 203F to receive the pilot signal transmitted from each base station. At this time, radio channel quality measuring section 205 of terminal 200 measures the radio channel quality based on the received pilot signal. The radio channel quality represents at least one of reception power and reception quality. The received power is, for example, reference signal received power (RSRP: Reference Signal Received Power) in LTE. The reception quality is, for example, a reference signal reception quality (RSRQ) in LTE. Based on the measured radio channel quality, radio channel controller 206F of terminal 200 selects a base station with the best radio channel quality or a cell in which the base station is defined from a plurality of base stations. A cell selection process is performed. Here, in the cell selection process, it is assumed that the radio channel controller 206F of the terminal 200 selects a cell in which the base station 100 is defined based on the measured radio channel quality (step S101).

The P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 notifies the terminal 200 of the system information of the P-SCG 10 (step S102). The system information of the P-SCG 10 is, for example, MIB, SIB, etc. in 3GPP. Step S102 may be performed in advance when step S100 is executed. Radio channel controller 206F of terminal 200 performs a random access procedure on base station 100 based on the system information of P-SCG 10 notified from base station 100 (step S103). The P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 performs radio communication between the P-SCG control unit 610 and the radio channel control unit 206F of the terminal 200 by random access based on the system information of the P-SCG 10. Line setting is performed (step S104).

The P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 is based on the communication quality when the radio channel between the P-SCG control unit 610 and the radio channel control unit 206F of the terminal 200 is established. An SCG selection process for selecting the optimum S-SCG is performed. For example, in the SCG selection process, the S-SCG 14 is selected as the optimum S-SCG from the S-SCGs 11 to 14 (step S105). Examples of communication quality include radio channel quality, CQI (Channel Quality Indicator), and QoS (Quality of Service). QoS is set by the terminal 200.

For example, among the control information included in the system information of P-SCG 10 and S-SCG 14, at least one of the subcarrier interval and the symbol length is different. Therefore, when the optimal S-SCG 14 is selected, the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 sends a system information transmission request for requesting transmission of system information of the S-SCG 14 to S. -It outputs to the SCG control part 614 (step S106).

In response to the system information transmission request output from the P-SCG control unit 610, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 sends the system information of the S-SCG 14 to the P-SCG control unit 610. Output (step S107). The system information of the S-SCG 14 is, for example, SIB in 3GPP. The P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 notifies the terminal 200 of the system information of the S-SCG 14 output from the S-SCG control unit 614 (step S108). The radio network controller 206F of the terminal 200 performs a random access procedure on the base station 100 based on the system information of the S-SCG 14 notified from the base station 100 (step S109). The S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 performs radio communication between the S-SCG control unit 614 and the radio channel control unit 206F of the terminal 200 by random access based on the system information of the S-SCG 14. A line is set (step S110).

The S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 performs data transmission using a radio channel between the S-SCG control unit 614 and the radio channel control unit 206F of the terminal 200 (step S111). .

Here, the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 performs control so that the terminal 200 can receive the system information of the P-SCG10. That is, P-SCG control unit 610 maintains a radio channel between P-SCG control unit 610 and radio channel control unit 206F of terminal 200 (step S112).

[2.5.2 SCG selection setting process (part 2)]
FIG. 17 is a sequence illustrating an example of the SCG selection setting process as the operation of the wireless communication system according to the first embodiment.

First, the same steps S100 to S110 as in FIG. 16 are performed. At this time, a radio channel is set between the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200. In this case, P-SCG control unit 610 of radio channel control unit 106F of base station 100 cancels the setting of the radio channel between P-SCG control unit 610 and radio channel control unit 206F of terminal 200 (step S120). ). Thereafter, the same step S111 as in FIG. 16 is performed. Here, when a situation occurs in which system information of the entire system band is notified from the base station 100 to the terminal 200, the system information of the entire system band is notified from the S-SCG control unit 614 to the terminal 200 (step S121). ).

[2.5.3 SCG selection setting process (part 3)]
FIG. 18 is a sequence illustrating an example of the SCG selection setting process as the operation of the wireless communication system according to the first embodiment.

First, the same steps S100 to S110, S120, S111, and S121 as in FIG. 17 are performed. At this time, the setting of the radio channel between the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200 is cancelled. Here, when the setting of the radio channel between the P-SCG control unit 610 and the radio channel control unit 206F of the terminal 200 is performed again (step S130), the system information of the entire system band is the P-SCG control unit. The terminal 200 is notified from 610 (step S131).

[2.6 Effects of the embodiment]
As described above, the wireless communication system according to the first embodiment includes the base station 100 and the terminal 200 that communicate using one system band. The base station 100 includes a radio network controller 106F that assigns first and second SCGs (P-SCG10, S-SCGs 11 to 14) having different system information within the system band. The radio network controller 106F includes a P-SCG controller 610 that is a first controller and S-SCG controllers 620 (S-SCG controllers 611 to 614) that are second controllers. The first control unit (P-SCG control unit 610) is based on the first system information that is the system information of the first SCG (P-SCG10), and the first control unit (P-SCG control unit 610). ) And the terminal 200 are set up for the first wireless line. At this time, the first control unit (P-SCG control unit 610) notifies the terminal 200 of second system information that is system information of the second SCG (for example, S-SCG 14). Among the control information included in the first and second system information, at least one of the subcarrier interval and the symbol length is different. The second control unit (S-SCG control unit 620) is configured between the second control unit (S-SCG control unit 620) and the terminal 200 based on the second system information notified to the terminal 200. The second wireless line is set up.

As described above, in the wireless communication system according to the first embodiment, when the base station 100 sets the first wireless line based on the first system information of the first SCG (P-SCG10), The terminal 200 is notified of the system information of the second SCG (S-SCG 14). For this reason, in the wireless communication system according to the first embodiment, the terminal 200 can perform wireless communication with the base station 100 by using different system information for each SCG.

Also, as described above, the S-SCG 14 is used for a high-quality low-delay service that the user of the terminal 200 intends to use. For this reason, in the wireless communication system according to the first embodiment, wireless communication suitable for the communication service that the user of the terminal 200 intends to use can be performed.

[3. Wireless communication system using F-OFDM (Example 2)]
Next, a radio communication system according to the second embodiment will be described. The radio communication system according to the second embodiment is a radio communication system that uses F-OFDM, similarly to the radio communication system according to the first embodiment.

[3.1 Change of SCG]
For example, when data transmission is performed between the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200, the S-SCG control unit 614 and the terminal 200 The communication state with the wireless line control unit 206F may deteriorate. Examples of the communication state include traffic volume, transmission speed, transmission delay, and the like. In this case, in the wireless communication system according to the second embodiment, the configuration of the S-SCG 14 to which the S-SCG control unit 614 is assigned is controlled. That is, the system information of the S-SCG 14 is controlled. Here, the control of the system information includes changing, adding, and deleting control information included in the system information.

As described above, the communication state includes traffic volume, transmission speed, transmission delay, and the like. Further, as described above, the system information includes control information such as radio resources, subcarrier intervals, symbol lengths, and subframe lengths.

As control of the system information of the S-SCG 14, for example, when the traffic volume is higher than the reference traffic volume, there is a possibility that the radio resources allocated to the S-SCG 14 are insufficient. In this case, a radio resource is newly added to the radio resource allocated to the S-SCG 14 in order to widen the frequency bandwidth.

Further, as control of system information of the S-SCG 14, even when the transmission rate is lower than the required transmission rate or when the transmission delay is larger than the reference transmission delay, a new resource is assigned to the radio resource allocated to the S-SCG 14. Radio resources are added to

Here, if the transmission rate exceeds the set transmission rate that is faster than the required transmission rate, there is a large margin in the transmission rate. Further, when the transmission delay exceeds the set transmission delay larger than the reference transmission delay, there is a large margin in the transmission delay. In such a case, as a control of the system information of the S-SCG 14, radio resources having a margin are deleted from the radio resources allocated to the S-SCG 14.

Further, as control of the system information of the S-SCG 14, the radio resource itself allocated to the S-SCG 14 may be changed in order to improve the transmission speed and transmission delay. For example, even with the same frequency bandwidth, it is possible to improve the transmission speed and transmission delay by changing the frequency.

Further, as control of the system information of the S-SCG 14, the symbol length, subframe length, and subcarrier interval allocated to the S-SCG 14 may be changed in order to improve the transmission rate and transmission delay. For example, it is possible to improve the transmission delay by shortening the symbol length assigned to the S-SCG 14 or shortening the subcarrier interval. Further, when there is a margin in the transmission rate or transmission delay, the margin of transmission delay can be reduced by increasing the assigned symbol length, increasing the subcarrier interval, or reducing the radio resources.

Thus, the configuration of the S-SCG 14 is changed by changing the system information of the S-SCG 14. In other words, the configuration of the S-SCG 14 is controlled by controlling the system information of the S-SCG 14. Although not shown in the following embodiments, even when there is a margin in transmission delay and transmission speed, and radio resources are reduced, symbol lengths are shortened, and subcarrier intervals are reduced, radio resources are added and symbol lengths are reduced. As in the case of the expansion of the subcarriers and the interval of the subcarriers, it can be easily performed.

However, when data transmission is performed between the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200, the S-SCG control unit 614 is assigned. In some cases, system information of the S-SCG 14 is controlled. In this case, in the wireless communication system according to the second embodiment, the SCG used by the user of the terminal 200 is changed from the S-SCG 14 to another SCG. In the wireless communication system according to the second embodiment, after the system information of the S-SCG 14 is controlled, the SCG used by the user of the terminal 200 is changed from another SCG to the S-SCG 14.

[3.2 Operation of Wireless Communication System According to Second Embodiment]
In the operation of the wireless communication system according to the second embodiment, the SCG changing process for changing the SCG is divided into, for example, the following cases (A) and (B).

In (A), when data transmission is performed between the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200, the S-SCG control unit 614 Is a case where the system information of the S-SCG 14 is controlled. In this case, the SCG used by the user of terminal 200 is changed from S-SCG 14 to another SCG.

In (B), when data transmission is performed between the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200, the P-SCG control unit 610 Is a case where the system information of the P-SCG 10 is controlled. In this case, the SCG used by the user of terminal 200 is changed from P-SCG 10 to another SCG.

[3.3 SCG change processing in case of (A)]
First, the SCG change process in the case of (A) will be described. Here, in the case of (A), it is further divided into (A1) and (A2).

In (A1), for example, the SCG used by the user of the terminal 200 is changed from S-SCG14 to P-SCG10.

In (A2), for example, the SCG used by the user of the terminal 200 is changed from S-SCG14 to S-SCG13.

[3.4 SCG change processing in case of (A1)]
First, the case of (A1) will be described.

[SCG change processing 1 in case of 3.4.1 (A1)]
FIG. 19 is a sequence illustrating an example of the SCG change process as the operation of the wireless communication system according to the second embodiment.

The S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 performs data transmission using a radio channel between the S-SCG control unit 614 and the radio channel control unit 206F of the terminal 200 (step). S200). At this time, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 measures the communication state (step S201). Examples of the measurement of the communication state include measurement of traffic volume, transmission speed, transmission delay, and the like.

Based on the measurement results, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200 are used. It is determined whether or not the communication state between the two has deteriorated (step S202).

For example, when the measurement result indicates that the traffic volume is higher than the reference traffic volume, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200 The communication status between them has deteriorated. When the measurement result indicates that the transmission rate is equal to or lower than the required transmission rate, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200 The communication status between them has deteriorated. When the measurement result indicates that the transmission delay exceeds the reference transmission delay, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200 The communication state between is getting worse.

On the other hand, when the measurement result indicates that the traffic volume is equal to or less than the reference traffic volume, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200 The communication status between them has not deteriorated. When the transmission rate is not less than the required transmission rate or when the transmission delay does not exceed the reference transmission delay, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the radio channel control of the terminal 200 The communication state with the unit 206F has not deteriorated.

If the communication state has not deteriorated (step S202: NO), step S201 is performed.

On the other hand, when the communication state has deteriorated (step S202: YES), the S-SCG control unit 614 transmits an SCG change request to the terminal 200 (step S203). The SCG change request is information for changing the SCG used by the user of the terminal 200 from the S-SCG 14 to the P-SCG 10. For example, among the control information included in the system information of P-SCG 10 and S-SCG 14, at least one of the subcarrier interval and the symbol length is different. Therefore, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 notifies the terminal 200 of the system information of the P-SCG 10 (step S204).

The terminal 200 performs a random access procedure for the base station 100 based on the SCG change request transmitted from the base station 100 and the system information of the P-SCG 10 notified from the base station 100. The P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 performs radio communication between the P-SCG control unit 610 and the radio channel control unit 206F of the terminal 200 by random access based on the system information of the P-SCG 10. A line is set (step S205).

Here, when a radio channel is set between the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200, the S-SCG control unit 614 The system information of the S-SCG 14 is controlled in consideration of the above. That is, the system information of the S-SCG 14 is changed in consideration of traffic volume, transmission speed, transmission delay, etc. (step S206).

For example, if the measurement result indicates that the traffic volume is higher than the reference traffic volume, there is a shortage of radio resources allocated to the S-SCG 14. In this case, as control of the system information of the S-SCG 14, a new radio resource is added to the radio resource allocated to the S-SCG 14 in order to widen the frequency bandwidth.

For example, the measurement result indicates that the transmission delay exceeds the reference transmission delay. In this case, as control of the system information of the S-SCG 14, the symbol length assigned to the S-SCG 14 is changed in order to improve transmission delay.

The S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 performs the P-SCG control of the system information of the S-SCG 14 when the change of the system information of the S-SCG 14 is completed, that is, after the system information is controlled. It outputs to the part 610 (step S207).

The P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 notifies the terminal 200 of the system information of the S-SCG 14 output from the S-SCG control unit 614 (step S208). Terminal 200 performs a random access procedure on base station 100 based on the system information of S-SCG 14 notified from base station 100. The S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 performs radio communication between the S-SCG control unit 614 and the radio channel control unit 206F of the terminal 200 by random access based on the system information of the S-SCG 14. Line setting is performed (step S209).

In this case, P-SCG control unit 610 of radio channel control unit 106F of base station 100 cancels the setting of the radio channel between P-SCG control unit 610 and radio channel control unit 206F of terminal 200 (step S210). ).

The S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 performs data transmission using a radio channel between the S-SCG control unit 614 and the radio channel control unit 206F of the terminal 200 (step S211). .

[SCG change processing 2 in case of 3.4.2 (A1)]
FIG. 20 is a sequence illustrating an example of the SCG change process as the operation of the wireless communication system according to the second embodiment. In FIG. 20, step S202 may be performed by the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100.

First, the same steps S200 and S201 as in FIG. 19 are performed. At this time, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 outputs the result of communication state measurement to the P-SCG control unit 610 (step S220). Thereafter, step S202 is performed by the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100.

Here, the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 determines that the communication state between the S-SCG control unit 614 and the radio channel control unit 206F of the terminal 200 has not deteriorated. (Step S202: NO). In this case, the P-SCG control unit 610 outputs a determination result indicating that the communication state has not deteriorated to the S-SCG control unit 614. In this case, step S201 is performed.

On the other hand, the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 determines that the communication state between the S-SCG control unit 614 and the radio channel control unit 206F of the terminal 200 has deteriorated ( Step S202: YES). In this case, the P-SCG control unit 610 outputs a determination result indicating that the communication state has deteriorated to the S-SCG control unit 614 (step S221). Thereafter, the same steps S203 to S211 as in FIG. 19 are performed.

[3.4.3 SCG change process 3 in case of (A1)]
FIG. 21 is a sequence illustrating an example of the SCG change process as the operation of the wireless communication system according to the second embodiment. In FIG. 21, steps S203 and S204 may be performed by the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100.

First, the same steps S200, S201, S220, S202, and S221 as in FIG. 20 are performed. At this time, the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 sends an SCG change request for changing the SCG used by the user of the terminal 200 from the S-SCG 14 to the P-SCG 10 200 (step S203). Also, the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 notifies the terminal 200 of system information of the P-SCG 10 (step S204). Thereafter, the same steps S205 to S209 as in FIG. 20 are performed.

Here, the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 performs control so that the terminal 200 can receive the system information of the P-SCG10. That is, P-SCG control unit 610 of radio channel control unit 106F of base station 100 maintains a radio channel between P-SCG control unit 610 and radio channel control unit 206F of terminal 200 (step S230). Further, the same step S211 as in FIG. 20 is performed.

[3.4.4 SCG change processing in case of (A1)]
Step S202 may be performed by a function other than the P-SCG control unit 610 and the S-SCG control units 611 to 614 of the radio channel control unit 106F of the base station 100. FIG. 22 is a diagram illustrating an example of the radio channel controller 106F of the base station 100 when F-OFDM is used in the radio communication system according to the second embodiment. For example, the radio network controller 106F of the base station 100 includes a determination unit 630 in addition to the P-SCG control unit 610 and the S-SCG control units 611 to 614.

FIG. 23 is a sequence illustrating an example of the SCG change process as the operation of the wireless communication system according to the second embodiment. In FIG. 23, step S202 is performed by the determination unit 630 of the base station 100.

First, the same steps S200 and S201 as in FIGS. 19 to 21 are performed. At this time, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 outputs the measurement result of the communication state to the determination unit 630 (step S220). Thereafter, the determination unit 630 performs step S202.

Here, determination section 630 of radio channel control section 106F of base station 100 determines that the communication state between S-SCG control section 614 and radio channel control section 206F of terminal 200 has not deteriorated (step S202). : NO). In this case, the determination unit 630 outputs a determination result indicating that the communication state has not deteriorated to the S-SCG control unit 614. In this case, step S201 is performed.

On the other hand, the determination unit 630 of the radio channel control unit 106F of the base station 100 determines that the communication state between the S-SCG control unit 614 and the radio channel control unit 206F of the terminal 200 has deteriorated (step S202: YES). In this case, the determination unit 630 outputs a determination result indicating that the communication state has deteriorated to the S-SCG control unit 614 (step S221). Thereafter, the same steps S203 to S209 as in FIGS. 19 and 20 are performed. Thereafter, the same step S230 as in FIG. 21 is performed, and the same step S211 as in FIGS. 19 to 21 is performed.

[Effect in the case of 3.4.5 (A1)]
As described above, in the wireless communication system according to the second embodiment, the SCG used by the user of the terminal 200 is changed from the S-SCG 14 to the P-SCG 10. In the wireless communication system according to the second embodiment, when the change of the system information of the S-SCG 14 is completed, that is, after the control of the system information, the SCG used by the user of the terminal 200 is changed from the P-SCG 10 to the S-SCG 10. -Change to SCG14. Therefore, in the wireless communication system according to the second embodiment, the system information of the S-SCG 14 can be flexibly controlled.

[3.5 SCG change processing in case of (A2)]
Next, the case of (A2) will be described.

[SCG change processing 1 in case of 3.5. 1 (A2)]
FIG. 24 is a sequence illustrating an example of the SCG change process as the operation of the wireless communication system according to the second embodiment.

The S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 performs data transmission using a radio channel between the S-SCG control unit 614 and the radio channel control unit 206F of the terminal 200 (step). S300). At this time, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 measures the communication state (step S301). Examples of the communication state include traffic volume, transmission speed, transmission delay, and the like.

Based on the measurement result, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 deteriorates the communication state between the S-SCG control unit 614 and the radio channel control unit 206F of the terminal 200. It is determined whether or not there is (step S302).

For example, when the measurement result indicates that the traffic volume is higher than the reference traffic volume, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200 The communication status between them has deteriorated. When the measurement result indicates that the transmission rate is equal to or lower than the required transmission rate, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200 The communication status between them has deteriorated. When the measurement result indicates that the transmission delay exceeds the reference transmission delay, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200 The communication state between is getting worse.

On the other hand, when the measurement result indicates that the traffic volume is equal to or less than the reference traffic volume, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200 The communication status between them has not deteriorated. When the transmission rate is not less than the required transmission rate or when the transmission delay does not exceed the reference transmission delay, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the radio channel control of the terminal 200 The communication state with the unit 206F has not deteriorated.

As a result of the determination, if the communication state has not deteriorated (step S302: NO), step S301 is performed.

As a result of the determination, if the communication state has deteriorated (step S302: YES), the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 sends a system information transmission request to the S-SCG control unit 613. Output (step S303). The system information transmission request is information for requesting transmission of system information of the S-SCG 13. In response to the system information transmission request output from the S-SCG control unit 614, the S-SCG control unit 613 of the radio channel control unit 106F of the base station 100 sends the system information of the S-SCG 13 to the S-SCG control unit 614. Output (step S304).

In addition, when the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 outputs the system information transmission request to the S-SCG control unit 613, the S-CG change request is transmitted to the terminal 200 (step S305). . The SCG change request is information for changing the SCG used by the user of the terminal 200 from the S-SCG 14 to the S-SCG 13. For example, among the control information included in the system information of S-SCG 13 and S-SCG 14, at least one of the subcarrier interval and the symbol length is different. Therefore, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 notifies the terminal 200 of the system information of the S-SCG 13 output from the S-SCG control unit 613 (step S306).

The terminal 200 performs a random access procedure on the base station 100 based on the SCG change request transmitted from the base station 100 and the system information of the S-SCG 13 notified from the base station 100. The S-SCG control unit 613 of the radio channel control unit 106F of the base station 100 performs radio communication between the S-SCG control unit 613 and the radio channel control unit 206F of the terminal 200 by random access based on the system information of the S-SCG 13. A line is set (step S307).

Here, when a radio channel between the S-SCG control unit 613 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200 is set, the S-SCG control unit 614 The system information of the S-SCG 14 is controlled in consideration of the above. That is, the system information of the S-SCG 14 is changed in consideration of traffic volume, transmission speed, transmission delay, etc. (step S308).

For example, if the measurement result indicates that the traffic volume is higher than the reference traffic volume, there is a shortage of radio resources allocated to the S-SCG 14. In this case, as control of the system information of the S-SCG 14, a new radio resource is added to the radio resource allocated to the S-SCG 14 in order to widen the frequency bandwidth.

For example, the measurement result indicates that the transmission delay exceeds the reference transmission delay. In this case, as control of the system information of the S-SCG 14, the symbol length assigned to the S-SCG 14 is changed in order to improve transmission delay.

The S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 performs S-SCG control on the system information of the S-SCG 14 when the change of the system information of the S-SCG 14 is completed, that is, after the system information is controlled. The data is output to the unit 613 (step S309).

The S-SCG control unit 613 of the radio channel control unit 106F of the base station 100 notifies the terminal 200 of the system information of the S-SCG 14 output from the S-SCG control unit 614 (step S310). Terminal 200 performs a random access procedure on base station 100 based on the system information of S-SCG 14 notified from base station 100. The S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 performs the random access based on the system information of the S-SCG 14, and the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the terminal 200 A wireless line is set up with the wireless line control unit 206F (step S311).

In this case, the S-SCG control unit 613 of the radio channel control unit 106F of the base station 100 is located between the S-SCG control unit 613 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200. The wireless line setting is canceled (step S312).

The S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 establishes a radio channel between the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200. Data transmission is performed using the data (step S313).

[SCG change processing 2 in case of 3.5.2 (A2)]
FIG. 25 is a sequence illustrating an example of the SCG change process as the operation of the wireless communication system according to the second embodiment. In FIG. 25, step S302 is performed by the determination unit 630 of the base station 100.

First, the same steps S300 and S301 as in FIG. 24 are performed. At this time, the S-SCG control unit 614 of the radio channel control unit 106F of the base station 100 outputs the result of communication state measurement to the determination unit 630 (step S320). Thereafter, the determination unit 630 performs step S302.

Here, the determination unit 630 of the radio channel controller 106F of the base station 100 determines that the communication state between the S-SCG controller 614 and the radio channel controller 206F of the terminal 200 has not deteriorated (step S302). : NO). In this case, the determination unit 630 outputs a determination result indicating that the communication state has not deteriorated to the S-SCG control unit 614. In this case, step S301 is performed.

On the other hand, the determination unit 630 of the radio channel control unit 106F of the base station 100 determines that the communication state between the S-SCG control unit 614 and the radio channel control unit 206F of the terminal 200 has deteriorated (step S302: YES). In this case, the determination unit 630 outputs a determination result indicating that the communication state has deteriorated to the S-SCG control unit 614 (step S321). Thereafter, the same steps S303 to S313 as in FIG. 24 are performed.

[Effect in the case of 3.5.3 (A2)]
As described above, in the wireless communication system according to the second embodiment, the SCG used by the user of the terminal 200 is changed from the S-SCG 14 to the S-SCG 13. In the wireless communication system according to the second embodiment, when the change of the system information of the S-SCG 14 is completed, that is, after the control of the system information, the SCG used by the user of the terminal 200 is changed from the S-SCG 13 to the S-SCG 13. -Change to SCG14. Therefore, in the wireless communication system according to the second embodiment, the system information of the S-SCG 14 can be flexibly controlled.

[SCG change processing in the case of 3.6 (B)]
Next, the SCG change process in the case of (B) will be described.

[SCG change processing in the case of 3.6.1 (B)]
FIG. 26 is a sequence illustrating an example of the SCG change process as the operation of the wireless communication system according to the second embodiment.

In (B), when data transmission is performed between the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200, the system information of the P-SCG 10 Is changed. In this case, for example, the SCG used by the user of the terminal 200 is changed from the P-SCG 10 to the S-SCG 11.

The P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 performs data transmission using a radio channel between the P-SCG control unit 610 and the radio channel control unit 206F of the terminal 200 (steps). S400). At this time, the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 measures the communication state (step S401). Examples of the measurement of the communication state include measurement of traffic volume, transmission speed, transmission delay, and the like.

The P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 outputs the result of communication state measurement to the determination unit 630 (step S420). Based on the measurement result, the determination unit 630 of the base station 100 deteriorates the communication state between the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200. It is determined whether or not (step S402).

For example, when the measurement result indicates that the traffic volume is higher than the reference traffic volume, the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200 The communication status between them has deteriorated. When the measurement result indicates that the transmission rate is equal to or lower than the required transmission rate, the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200 The communication status between them has deteriorated. If the measurement result indicates that the transmission delay exceeds the reference transmission delay, the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200 The communication state between is getting worse.

On the other hand, when the measurement result indicates that the traffic volume is equal to or less than the reference traffic volume, the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200 The communication status between them has not deteriorated. When the transmission rate is not less than the required transmission rate or when the transmission delay does not exceed the reference transmission delay, the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 and the radio channel control of the terminal 200 The communication state with the unit 206F has not deteriorated.

Here, determination section 630 of radio channel control section 106F of base station 100 determines that the communication state between P-SCG control section 610 and radio channel control section 206F of terminal 200 has not deteriorated (step S402). : NO). In this case, the determination unit 630 outputs a determination result indicating that the communication state has not deteriorated to the P-SCG control unit 610. In this case, step S401 is performed.

On the other hand, the determination unit 630 of the radio channel control unit 106F of the base station 100 determines that the communication state between the P-SCG control unit 610 and the radio channel control unit 206F of the terminal 200 has deteriorated (step S402: YES). In this case, the determination unit 630 outputs a determination result indicating that the communication state has deteriorated to the P-SCG control unit 610 (step S421). The P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 sends a system information transmission request to one of the S-SCG control units 611 to 614 according to the determination result output from the determination unit 630. -Output to the SCG control unit. For example, the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 outputs a system information transmission request to the S-SCG control unit 611 (step S403). The system information transmission request is information for requesting transmission of system information of the S-SCG 11. In response to the system information transmission request output from the P-SCG control unit 610, the S-SCG control unit 611 outputs the system information of the S-SCG 11 to the P-SCG control unit 610 (step S404).

Also, when the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 outputs a system information transmission request to the S-SCG control unit 611, it transmits an SCG change request to the terminal 200 (step S405). . The SCG change request is information for changing the SCG used by the user of the terminal 200 from the P-SCG 10 to the S-SCG 11. For example, among the control information included in the system information of S-SCG 11 and P-SCG 10, at least one of the subcarrier interval and the symbol length is different. Therefore, the P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 notifies the terminal 200 of the system information of the S-SCG 11 output from the S-SCG control unit 611 (step S406).

Terminal 200 performs a random access procedure for base station 100 based on the SCG change request transmitted from base station 100 and the system information of S-SCG 11 notified from base station 100. The S-SCG control unit 611 of the radio channel control unit 106F of the base station 100 performs radio communication between the S-SCG control unit 611 and the radio channel control unit 206F of the terminal 200 by random access based on the system information of the S-SCG 11. Line setting is performed (step S407).

Here, when the radio channel between the S-SCG control unit 611 of the radio channel control unit 106F of the base station 100 and the radio channel control unit 206F of the terminal 200 is set, the P-SCG control unit 610 The system information of the P-SCG 10 is controlled in consideration of the above. That is, the system information of the P-SCG 10 is changed in consideration of traffic volume, transmission speed, transmission delay, etc. (step S408).

For example, if the measurement result indicates that the traffic volume is higher than the reference traffic volume, there is a shortage of radio resources allocated to the P-SCG 10. In this case, as control of the system information of the P-SCG 10, a radio resource is newly added to the radio resource allocated to the P-SCG 10 in order to widen the frequency bandwidth.

For example, the measurement result indicates that the transmission delay exceeds the reference transmission delay. In this case, as control of the system information of the P-SCG 10, the symbol length assigned to the P-SCG 10 is changed in order to improve transmission delay.

The P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 performs S-SCG control on the system information of the P-SCG 10 when the change of the system information of the P-SCG 10 is completed, that is, after the system information is controlled. The data is output to the unit 611 (step S409).

The S-SCG control unit 611 of the radio channel control unit 106F of the base station 100 notifies the terminal 200 of the system information of the P-SCG 10 output from the P-SCG control unit 610 (step S410). Terminal 200 performs a random access procedure on base station 100 based on the system information of P-SCG 10 notified from base station 100. The P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 performs radio communication between the P-SCG control unit 610 and the radio channel control unit 206F of the terminal 200 by random access based on the system information of the P-SCG 10. Line setting is performed (step S411).

In this case, the S-SCG control unit 611 of the radio channel control unit 106F of the base station 100 cancels the setting of the radio channel between the S-SCG control unit 611 and the radio channel control unit 206F of the terminal 200 (step S412). ).

The P-SCG control unit 610 of the radio channel control unit 106F of the base station 100 performs data transmission using a radio channel between the P-SCG control unit 610 and the radio channel control unit 206F of the terminal 200 (step S413). .

[Effect in the case of 3.6.2 (B)]
As described above, in the wireless communication system according to the second embodiment, the SCG used by the user of the terminal 200 is changed from the P-SCG 10 to the S-SCG 11. In the wireless communication system according to the second embodiment, when the change of the system information of the P-SCG 10 is completed, that is, after the control of the system information, the SCG used by the user of the terminal 200 is changed from the S-SCG 11 to the P- -Change to SCG10. Therefore, in the wireless communication system according to the second embodiment, the system information of the P-SCG 10 can be flexibly controlled.

[3.7 Addition of SCG]
In the wireless communication system according to the second embodiment, when a new service is requested from the terminal 200, if an S-SCG corresponding to the requested service does not exist in the system band, a new service is newly added in the system band. S-SCG may be added. For example, in FIGS. 9 and 15, the radio network controller 106F of the base station 100 allocates S-SCGs 11 to 13 in the system band as the second subcarrier group, but the second subcarrier group corresponds to the requested service. No subcarrier group exists in the system band. In this case, the radio network controller 106F of the base station 100 newly allocates (adds) the second subcarrier group corresponding to the requested service as the S-SCG 14 within the system band. In addition, the S-SCG control unit 614 is newly provided for the added S-SCG 14 in the radio channel control unit 106F of the base station 100. Further, the added system information of the S-SCG 14 is stored in the system information storage unit 112F of the base station 100.

[3.8 Deletion of SCG]
Also, in the wireless communication system according to the second embodiment, in a SCG set for at least one service, when there is no terminal that performs communication for a certain period, the SCG may be deleted. For example, in FIGS. 9 and 15, the radio network controller 106F of the base station 100 allocates S-SCGs 11 to 14 in the system band as the second subcarrier group. Therefore, there is an S-SCG 11 in which communication is not performed for a certain period. In this case, the radio network controller 106F of the base station 100 deletes the S-SCG 11 for which communication is not performed for a certain period. Note that the SCG may be deleted as soon as it is detected that there is no terminal that performs communication.

FIG. 27 is a flowchart illustrating an example of the SCG deletion process as the operation of the wireless communication system according to the second embodiment.

For example, in the base station 100, the S-SCG control unit assigned to a certain S-SCG counts the number N of terminals, which is the number of terminals communicating with itself using a radio channel (step S500). The S-SCG control unit determines whether or not the number of terminals N is equal to or less than the set number of terminals Nth (step S501).

As a result of the determination, if the number of terminals N is not less than or equal to the set number of terminals Nth (step S501: NO), step S500 is performed. On the other hand, as a result of the determination, when the number N of terminals is equal to or less than the set number Nth (step S501: YES), the S-SCG control unit determines whether the number N of terminals is 0 (step S502). .

As a result of the determination, if the number N of terminals is 0 (step S502: YES), the corresponding S-SCG is deleted (step S504). That is, the S-SCG to which the S-SCG control unit is assigned is deleted. On the other hand, when the number N of terminals is not 0 as a result of the determination (step S502: NO), the S-SCG control unit performs SCG on N terminals communicating with itself using a wireless line. A change request is made (step S503). Thereafter, step S504 is performed.

When the number N of terminals is equal to or less than the set number Nth (step S501: YES), the S-SCG control unit sets a timer, and when a predetermined time has elapsed by the timer, step S504 is performed. Also good. Further, when the number N of terminals is equal to or less than the set number Nth (step S501: YES), step S504 may be performed immediately. For example, in the S-SCG 11, if the traffic (communication amount) is equal to or less than a certain amount, the terminal in communication may be moved to another SCG and the S-SCG 11 may be deleted as described above.

[Other embodiments]
Each component in Examples 1 and 2 does not necessarily need to be physically configured as illustrated. In other words, the specific form of distribution / integration of each part is not limited to the one shown in the figure, and all or a part thereof may be functionally or physically distributed / integrated in arbitrary units according to various loads and usage conditions. Can be configured.

Furthermore, various processes performed by each device are executed entirely or arbitrarily on a CPU (Central Processing Unit) (or a micro computer such as MPU (Micro Processing Unit) or MCU (Micro Controller Unit)). You may make it do. Various processes may be executed in whole or in any part on a program that is analyzed and executed by a CPU (or a microcomputer such as an MPU or MCU) or hardware based on wired logic.

The base station 100 and the terminal 200 according to the first and second embodiments can be realized by the following hardware configuration, for example.

FIG. 28 is a diagram illustrating an example of a hardware configuration of the base station 100. The base station 100 includes a processor 1001, a memory 1002, an RF (Radio Frequency) unit 1003, an antenna 1004, and a network interface (IF) 1005. Examples of the processor 1001 include a CPU, a DSP (Digital Signal Processor), and an FPGA (Field Programmable Gate Array). Examples of the memory 1002 include a RAM (Random Access Memory) such as SDRAM (Synchronous Dynamic Random Access Memory), a ROM (Read Only Memory), a flash memory, and the like.

Various processes performed in the base station 100 according to the first and second embodiments may be realized by the processor 1001 executing programs stored in various memories such as a nonvolatile storage medium. That is, it corresponds to each process executed by the reception signal processing unit 103F, the control signal extraction unit 104, the radio channel quality measurement unit 105, the radio channel control unit 106F, the control signal generation unit 107, the buffer 108, and the transmission signal processing unit 109F. The program may be recorded in the memory 1002 and each program may be executed by the processor 1001. The system information storage unit 112F is realized by the memory 1002. The reception radio unit 102, the transmission radio unit 110, and the subcarrier generation unit 111 are realized by the RF unit 1003. The antenna 101 is realized by the antenna 1004.

Here, the various processes performed in the base station 100 of the first and second embodiments are executed by one processor 1001, but the present invention is not limited to this, and may be executed by a plurality of processors. Good.

FIG. 29 is a diagram illustrating an example of a hardware configuration of the terminal 200. The terminal 200 includes a processor 2001, a memory 2002, an RF unit 2003, and an antenna 2004. Examples of the processor 2001 include a CPU, a DSP, and an FPGA. Further, examples of the memory 2002 include RAM such as SDRAM, ROM, flash memory, and the like.

The various processes performed by the terminal 200 according to the first and second embodiments may be realized by the processor 2001 executing programs stored in various memories such as a nonvolatile storage medium. That is, it corresponds to each process executed by the reception signal processing unit 203F, the control signal extraction unit 204, the radio channel quality measurement unit 205, the radio channel control unit 206F, the control signal generation unit 207, the buffer 208, and the transmission signal processing unit 209F. The program may be recorded in the memory 2002, and each program may be executed by the processor 2001. Further, the system information storage unit 212 is realized by the memory 2002. In addition, the reception radio unit 202, the transmission radio unit 210, and the subcarrier generation unit 211 are realized by the RF unit 2003. The antenna 201 is realized by the antenna 2004.

Here, the various processes performed in the terminal 200 of the first and second embodiments are executed by one processor 1001, but the present invention is not limited to this, and may be executed by a plurality of processors. .

1-3 SCG
10 P-SCG
11-14 S-SCG
20-24 RNS
30-34 NS
41 MME
42 SGW
43 PGW
DESCRIPTION OF SYMBOLS 100 Base station 101 Antenna 102 Reception radio | wireless part 103, 103F Reception signal processing part 104 Control signal extraction part 105 Radio channel quality measurement part 106, 106F Radio channel control part 107 Control signal generation part 108 Buffer 109, 109F Transmission signal processing part 110 Transmission Radio unit 111 Subcarrier generation unit 112, 112F System information storage unit 200 Terminal 201 Antenna 202 Reception radio unit 203, 203F Reception signal processing unit 204 Control signal extraction unit 205 Radio channel quality measurement unit 206, 206F Radio channel control unit 207 Control signal Generation unit 208 Buffer 209, 209F Transmission signal processing unit 210 Transmission radio unit 211 Subcarrier generation unit 212 System information storage unit 301 ADC
302 CP removing unit 303 FFT unit 304 Demodulating / decoding unit 401 Encoding / modulating unit 402 Subcarrier mapping unit 403 IFFT unit 404 CP adding unit 405 DAC
610 P-SCG control unit 611 to 614, 620 S-SCG control unit 630 determination unit 1001 processor 1002 memory 1003 RF unit 1004 antenna 1005 network IF
2001 Processor 2002 Memory 2003 RF unit 2004 Antenna

Claims (13)

In a base station of a wireless communication system including a base station and a terminal that communicate using one system band,
A radio network controller that allocates first and second subcarrier groups having different system information within a system band; and
Based on the first system information that is the system information of the first subcarrier group, the first radio channel is set up with the terminal, and the second information that is the system information of the second subcarrier group. A first control unit for notifying the terminal of the system information;
Based on the second system information notified to the terminal, a second control unit configured to set a second wireless line with the terminal;
A base station comprising: 2. The base station according to claim 1, wherein at least one of a subcarrier interval and a symbol length is different among the control information included in the first and second system information. A plurality of the second subcarrier groups are allocated within the system band, and system information of the plurality of second subcarrier groups is different from the first system information,
The first controller is
After establishing the first radio link, selecting one second subcarrier group of the plurality of second subcarrier groups;
Notifying the terminal of the second system information that is system information of the selected second subcarrier group;
The second controller is
Based on the second system information notified to the terminal, setting a second wireless line between the second control unit and the terminal,
The base station according to claim 1. The first control unit or the second control unit notifies the terminal of the first system information,
The first control unit performs the setting of the first wireless line between the first control unit and the terminal based on the first system information notified to the terminal,
The second control unit controls the second system information;
The first control unit notifies the terminal of the second system information after the control,
The second control unit sets the second radio channel between the second control unit and the terminal based on the second system information after the control notified to the terminal. ,
The base station according to claim 3. The first control unit cancels the setting of the first wireless line when the second wireless line is set;
The base station according to claim 3 or 4, wherein The second controller is
Notifying the terminal of third system information that is system information of a second subcarrier group different from the selected second subcarrier group among the plurality of second subcarrier groups;
Based on the third system information notified to the terminal, setting a third wireless line between the second control unit and the terminal,
Controlling the second system information;
Notifying the terminal of the second system information after the control,
Based on the second system information after the control notified to the terminal, setting the second wireless line between the second control unit and the terminal,
The base station according to claim 3. The second control unit cancels the setting of the third wireless line when the second wireless line is set;
The base station according to claim 6. A plurality of the second subcarrier groups are allocated within the system band, and system information of the plurality of second subcarrier groups is different from the first system information,
The first control unit notifies the terminal of the second system information, which is system information of one second subcarrier group of the plurality of second subcarrier groups,
The second control unit, based on the system information of the one second subcarrier group notified to the terminal, of the second radio channel between the second control unit and the terminal Set up
The first control unit controls the first system information,
The second control unit notifies the terminal of the first system information after the control,
The first control unit sets the first wireless line between the first control unit and the terminal based on the first system information after the control notified to the terminal. ,
The base station according to claim 1. The radio network controller newly adds a second subcarrier group corresponding to the requested service in the system band;
The base station according to claim 1. A plurality of the second subcarrier groups are allocated within the system band, and system information of the plurality of second subcarrier groups is different from the first system information,
The radio network controller deletes a second subcarrier group in which communication with the terminal is not performed for a certain period from the plurality of second subcarrier groups.
The base station according to claim 1. In a terminal of a wireless communication system including a base station and a terminal that communicate using one system band,
A radio network controller that allocates first and second subcarrier groups having different system information within a system band; and
A first control unit configured to set up a first radio channel between the base station and the own terminal based on the first system information which is the system information of the first subcarrier group;
A receiving unit that receives second system information that is system information of the second subcarrier group notified from the base station;
A second control unit configured to set up a second wireless channel between the base station and the own terminal based on the received second system information;
A terminal comprising: In a wireless communication system including a base station and a terminal that communicate using one system band,
A base station,
A terminal,
Comprising
The base station
A radio network controller that allocates first and second subcarrier groups having different system information within a system band; and
Based on the first system information which is the system information of the first subcarrier group, the first radio link with the terminal is set, and the system information of the second subcarrier group is the first. A first control unit for notifying the terminal of system information of 2;
Comprising
The terminal
A receiving unit for receiving the second system information notified from the base station;
Based on the received second system information, a second control unit configured to set up a second wireless link with the base station;
A wireless communication system comprising: In a radio communication method of a radio communication system including a base station and a terminal that communicate using one system band,
The base station
Assigning first and second subcarrier groups having different system information within the system band;
Based on the first system information that is the system information of the first subcarrier group, the first wireless link with the terminal is set,
Notifying the terminal of second system information that is system information of the second subcarrier group;
The terminal
Receiving the second system information notified from the base station;
Based on the received second system information, setting a second wireless link with the base station,
A wireless communication method characterized by executing processing.

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