JP7395400B2 - Communication device - Google Patents

Description

The present invention relates to a communication device compatible with a fronthaul interface.

The 3rd Generation Partnership Project (3GPP) has standardized Long Term Evolution (LTE), and has developed LTE-Advanced (hereinafter referred to as LTE including LTE-Advanced) with the aim of further increasing the speed of LTE, and the 5th generation mobile communication system. (hereinafter also referred to as 5G, New Radio (NR) or Next Generation (NG)) specifications are also being developed. Furthermore, specifications for mobile communication systems after 5G are also being developed (sometimes called 6G, beyond 5G, etc., but not limited to these names) (for example, Non-Patent Document 1).

3GPP TS38.300 v15.8.0

By the way, in the above-mentioned LTE, a mechanism (for example, C-RAN; Centralized Radio Access Network) for connecting an LTE slave station (hereinafter referred to as first slave station) to an LTE master station (hereinafter referred to as first master station) is known. There is. The interface between the first master station and the first slave station is sometimes called CPRI (Common Public Radio Interface). The first master station may be called a BBU (Base Band Unit) or a CU (Central Unit). The first slave station may be called an RRH (Remote Radio Head) or a DU (Distributed Unit).

On the other hand, in the 5G mentioned above, a mechanism (for example, O-RAN; Open Radio Access Network) that connects an NR slave station (hereinafter referred to as second slave station) to an NR master station (hereinafter referred to as second master station) is well known. It is being The interface between the second master station and the second slave station is sometimes referred to as eCPRI (Evolved Common Public Radio Interface). The second master station may be called an O-DU (O-RAN Distributed Unit), and the second child station may be called an O-RU (O-RAN Radio Unit).

Against this background, as a result of intensive study, the inventors came up with a new idea of using the existing first slave station to quickly expand the NR coverage area.

Therefore, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a relay device that makes it possible to use a first slave station.

One aspect of the disclosure is a communication device including: a first communication unit that communicates signals based on a first interface with a first master station; and a second communication unit that communicates signals based on a second interface with a second base station. a second communication unit that executes communication of a signal that conforms to the first interface, a third communication unit that executes communication of a signal that conforms to the first interface, and a third communication unit that executes communication of a signal that conforms to the first interface and a signal that conforms to the second interface. a control unit that executes a conversion process between the first base station and identify a subframe number corresponding to the second master station, based on an information element included in a signal received from the second master station, and identify a subframe number corresponding to the first master station; performing synchronization control to synchronize the signal received from the first master station and the signal received from the second master station based on the subframe number corresponding to the second master station and the subframe number corresponding to the second master station; The gist is that.

FIG. 1 is an overall schematic configuration diagram of a wireless communication system 10 according to an embodiment. FIG. 2 is a diagram illustrating an example of the internal configuration of the eNB 100 that employs a C-RAN fronthaul (FH) interface according to the embodiment. FIG. 3 is a diagram illustrating an example of the internal configuration of the gNB 200 that employs the O-RAN fronthaul (FH) interface according to the embodiment. FIG. 4 is a diagram for explaining an application scene according to the embodiment. FIG. 5 is a functional block configuration diagram of the first master station 110 according to the embodiment. FIG. 6 is a functional block configuration diagram of the second master station 210 according to the embodiment. FIG. 7 is a functional block configuration diagram of the intermediate device 300 according to the embodiment. FIG. 8 is a diagram for explaining the delay time according to the embodiment. FIG. 9 is a diagram for explaining a DL delay profile in O-RAN according to the embodiment. FIG. 10 is a diagram for explaining DL adjustment processing according to the embodiment. FIG. 11 is a diagram for explaining a UL delay profile in O-RAN according to the embodiment. FIG. 12 is a diagram for explaining the UL adjustment process according to the embodiment. FIG. 13 is a diagram for explaining adjustment processing according to modification example 1. FIG. 14 is a diagram for explaining the combining process and separation process according to modification example 2. FIG. 15 is a diagram for explaining the combining process and separation process according to modification example 2. FIG. 16 is a diagram for explaining the DSS according to modification example 3. FIG. 17 is a diagram for explaining synchronization processing according to modification example 3. FIG. 18 is a diagram showing an example of the hardware configuration of the first master station 110, the second master station 210, and the intermediate device 300.

Hereinafter, embodiments will be described based on the drawings. Note that the same functions and configurations are given the same or similar symbols, and the description thereof will be omitted as appropriate.

[Embodiment]
(1) Overall schematic configuration of wireless communication system FIG. 1 is an overall schematic configuration diagram of a wireless communication system 10 according to an embodiment. The wireless communication system 10 is a wireless communication system that complies with Long Term Evolution (LTE) and 5G New Radio (NR). Note that LTE may be called 4G, and NR may be called 5G. LTE and NR may be interpreted as radio access technologies (RATs), and in embodiments, LTE may be referred to as the first radio access technology and NR may be referred to as the second radio access technology. NR may also be considered to include radio access technologies after 5G (for example, beyond 5G, evolved 5G, 6G, etc.).

The wireless communication system 10 includes an Evolved Universal Terrestrial Radio Access Network 31 (hereinafter referred to as E-UTRAN31), a Next Generation-Radio Access Network 32 (hereinafter referred to as NG RAN32), and a core network 33. Wireless communication system 10 includes terminal 20.

E-UTRAN31 includes eNB100, which is a base station compliant with LTE. eNB100 has one or more cells C11. E-UTRAN31 may include two or more eNB100.

NG RAN32 includes gNB200, which is a base station compliant with 5G (NR). gNB200 has one or more cells C21. NG RAN32 may include two or more gNB200.

The term "cell" may be used to mean a function that eNB 100 or gNB 200 has, that is, a function to communicate with terminal 20. The term "cell" may be used to mean the coverage area of eNB 100 or gNB 200. Each cell may be distinguished by the frequency used in each cell. E-UTRAN31 and NG RAN32 (which may be eNB100 or gNB200) may be simply called a radio access network or an access network.

eNB100, gNB200, and terminal 20 may support carrier aggregation (CA) that uses multiple component carriers (CC), and dual connectivity (DC) that simultaneously transmits component carriers between multiple eNB100 and terminal 20. ), it may also support dual connectivity (DC) that simultaneously transmits component carriers between multiple gNB200s and the terminal 20, and it may support dual connectivity (DC) that simultaneously transmits component carriers between eNB100 and gNB200 and the terminal 20. It may also support dual connectivity (DC) for transmission.

eNB100, gNB200, and terminal 20 perform wireless communication via radio bearers. Radio bearers may include Signaling Radio Bearers (SRBs) and Data Radio Bearers (DRBs).

The terminal 20 may be called a "mobile station (MS)" or a "user equipment (UE)", although this is not particularly limited.

The core network 33 includes an EPC (Evolved Packet Core) according to LTE and a 5G Core according to 5G (NR). The EPC may include an LTE-compliant network node (eg, Mobility Management Entity (MME)). 5G Core may include a network node (eg, AMF (Access and Mobility Management Function)) that complies with 5G (NR). MME and AMF are network nodes that execute processing related to the C-plane (control plane). A node may also be referred to as a function.

Here, the interface between eNB100 and MME and the interface between gNB200 and MME may be referred to as an S1 interface. The interface between gNB200 and AMF may be referred to as NG interface or N2 interface. The interface between eNB100 and eNB100 and the interface between eNB100 and gNB200 may be referred to as an X2 interface. The interface between gNB200 and gNB200 may be referred to as an Xn interface. The interface between the MME and the AMF may be referred to as the N26 interface.

In embodiments, the eNB 100 may employ a fronthaul (FH) interface defined by C-RAN (Centralized Radio Access Network). The gNB200 may employ a fronthaul (FH) interface defined by O-RAN (Open Radio Access Network).

(2) C-RAN fronthaul configuration Figure 2 shows an example of the internal configuration of an eNB 100 that employs a C-RAN fronthaul (FH) interface. As shown in FIG. 2, the eNB 100 includes a BBU 110 (Base Band Unit) and an RRH 120 (Remote Radio Head). The BBU 110 and the RRH 120 are functionally separated within a layer defined by 3GPP.

BBU 110 performs signal communication based on the first interface. For example, the first interface is CPRI (Common Public Radio Interface). A CPRI compliant signal is a time domain OFDM signal. In the embodiment, the BBU 110 functions as a first master station, and may be referred to as the first master station 110 below. BBU 110 is primarily a logical node that hosts the Packet Data Convergence Protocol layer (PDCP), Radio Link Control Layer (RLC), and Medium Access Control Layer (MAC). RRH 120 may host part of the physical layer (PHY). Here, the BBU 110 is provided closer to the E-UTRAN 31 than the RRH 120. In the following, the side closer to E-UTRAN31 may be referred to as the RAN side.

The RRH 120 executes signal communication based on the first interface (hereinafter referred to as CPRI). In the embodiment, the RRH 120 functions as a first slave station, and may be referred to as the first slave station 120 below. RRH 120 is primarily a logical node that hosts RF processing. Here, the RRH 120 is provided on the side of the BBU 110 that is remote from the E-UTRAN 31. In the following, the side remote from E-UTRAN31 may be referred to as the radio (air) side.

Additionally, eNB 100 includes logical nodes that host Radio Resource Control (RRC) and other control functions.

Note that the fronthaul (FH) may be interpreted as a line between a baseband processing unit of a wireless base station (base station device) and a wireless device, and an optical fiber or the like is used.

(3) O-RAN fronthaul configuration Figure 3 shows an example of the internal configuration of gNB200 that employs an O-RAN fronthaul (FH) interface. As shown in FIG. 3, the gNB 200 includes an O-DU 210 (O-RAN Distributed Unit) and an O-RU 220 (O-RAN Radio Unit). The O-DU 210 and the O-RU 220 are functionally separated within the physical (PHY) layer defined by 3GPP.

The O-DU 210 performs signal communication based on the second interface. For example, the second interface is eCPRI (evolved Common Public Radio Interface). Signals that comply with eCPRI are frequency domain OFDM signals. In the embodiment, O-DU 210 functions as a second master station, and may be referred to as second master station 210 below. O-DU 210 may be referred to as an O-RAN distributed unit. O-DU 210 is a logical node that mainly hosts the lower layer functional based Radio Link Control Layer (RLC), Medium Access Control Layer (MAC) and PHY-High layer. Here, the O-DU 210 is provided closer to the NG RAN 32 than the O-RU 220. In the following, the side closer to NG RAN32 may be referred to as the RAN side.

The O-RU 220 executes signal communication based on the second interface (hereinafter referred to as eCPRI). O-RU 220 may be referred to as an O-RAN radio unit. The O-RU 220 is a logical node that primarily hosts the PHY-Low layer and RF processing based on low-layer functional division. Here, the O-RU 220 is provided on the side remote from the NG RAN 32 with respect to the O-DU 210. In the following, the side remote from the NG RAN 32 may be referred to as the radio (air) side.

The PHY-High layer is the part of the PHY processing on the O-DU 210 side of the fronthaul interface, such as Forward Error Correction (FEC) encoding/decoding, scrambling, and modulation/demodulation.

The PHY-Low layer is the part of the PHY processing on the O-RU 220 side of the fronthaul interface, such as Fast Fourier Transform (FFT)/iFFT, digital beamforming, Physical Random Access Channel (PRACH) extraction and filtering.

O-CU stands for O-RAN Control Unit and is a logical node that hosts Packet Data Convergence Protocol (PDCP), Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and other control functions. .

Note that the fronthaul (FH) may be interpreted as a line between a baseband processing unit of a wireless base station (base station device) and a wireless device, and an optical fiber or the like is used.

Here, in the FH between the O-DU 210 and the O-RU 220, the following signals are communicated. Specifically, in the FH between the O-DU 210 and the O-RU 220, signals are communicated in multiple planes (for example, U/C/M/S-plane).

U-Plane is a protocol for transferring user data, and C-Plane is a protocol for transferring control signals. M-Plane is a management plane that handles maintenance monitoring signals, and S-Plane is a protocol for achieving synchronization between devices.

Specifically, the U-Plane signal includes signals that the O-RU 220 transmits to the wireless section (DL) and receives from the wireless section (UL), and is exchanged as a digital IQ signal. In addition to the so-called U-Plane (User Datagram Protocol (UDP) and Transmission Control Protocol (TCP), etc.), C-Plane (RRC, Non-Access Stratum (NAS), etc.) defined by 3GPP is also considered from the FH perspective. It is necessary to keep in mind that everything will be U-Plane.

The C-Plane signal includes signals necessary for various controls regarding transmission and reception of the U-Plane signal (signal for reporting information related to corresponding U-Plane radio resource mapping and beamforming). It should be noted that C-Plane (RRC, NAS, etc.) defined by 3GPP refers to a completely different signal.

M-Plane signals include signals necessary for managing O-DU210/O-RU220. For example, it is a signal for notifying various hardware (HW) capabilities of O-RU220 from O-RU220, or for notifying various setting values from O-DU210 to O-RU220.

The S-Plane signal is a signal necessary for synchronous control between O-DU210/O-RU220.

(4) Application Scene FIG. 4 is a diagram for explaining an application scene according to the embodiment. The applicable scene is a case where both the first master station 110 (for example, BBU) and the second master station 210 (for example, O-DU) communicate signals via the first slave station 120 (for example, RRH). Suppose. As shown in FIG. 4, an intermediate device 300 relays communication between the first master station 110 and the first slave station 120, and relays communication between the second master station 210 and the first slave station 120. provided. Intermediate device 300 is an example of a communication device.

Intermediate device 300 communicates with first master station 110 using signals compliant with CPRI. The intermediate device 300 communicates with the second master station 210 using eCPRI-compliant signals. Intermediate device 300 communicates with first slave station 120 using signals that comply with CPRI.

Here, the intermediate device 300 executes conversion processing between a signal compliant with CPRI (hereinafter referred to as CPRI signal) and a signal compliant with eCPRI (hereinafter referred to as eCPRI signal). Specifically, the intermediate device 300 converts the eCPRI signal received from the second master station 210 into a CPRI signal, and converts the CPRI signal received from the first slave station 120 into an eCPRI signal. The transformation process may include an IFFT (Inverse Fast Fourier Transform) that transforms an eCPRI signal, which is a frequency domain signal, into a CPRI signal, which is a time domain signal. The transformation process may include FFT (Fast Fourier Transform) that transforms a CPRI signal, which is a time domain signal, into an eCPRI signal, which is a frequency domain signal. The conversion process may include a process of converting the signal format of the eCPRI signal to a CPRI signal format, or may include a process of converting the signal format of the CPRI signal to the eCPRI signal format.

Further, the intermediate device 300 may perform a combining process of combining the CPRI signal received from the first master station 110 and the eCPRI signal (CPRI signal after conversion processing) received from the second master station 210. The intermediate device 300 performs separation processing to separate the CPRI signal received from the first slave station 120 into a CPRI signal destined for the first master station 110 and a CPRI signal destined for the second master station 210 (eCPRI signal after conversion processing). May be executed. Combination processing and separation processing are performed by multiplexer 301. Multiplexer 301 may also be referred to as demultiplexer 301.

Under such a background, the second master station 210 (for example, O-DU) may treat the intermediate device 300 and the first slave station 120 as the O-RU 220.

(5) Functional block configuration of wireless communication system Next, the functional block configuration of the wireless communication system 10 will be explained. Specifically, the functional block configurations of the first master station 110, the second master station 210, and the intermediate device 300 will be described.

(5.1) First master station 110
FIG. 5 is a functional block configuration diagram of the first master station 110. As shown in FIG. 5, the first master station 110 includes a communication section 111 and a control section 113.

The communication unit 111 executes communication of CPRI signals conforming to CPRI. Communication unit 111 transmits the CPRI signal to intermediate device 300 and receives the CPRI signal from the intermediate device.

The control unit 113 controls the first master station 110. The control unit 113 adjusts the timing of transmitting the CPRI signal from the first master station 110 so that the wireless transmission timing of the first slave station 120 is a predetermined timing.

(5.2) Second master station 210
FIG. 6 is a functional block configuration diagram of the second master station 210. As shown in FIG. 6, the second master station 210 includes a communication section 121 and a control section 213.

The communication unit 121 executes communication of eCPRI signals conforming to eCPRI. The communication unit 121 transmits the eCPRI signal to the intermediate device 300 and receives the eCPRI signal from the intermediate device.

The control unit 213 controls the second master station 210. The control unit 213 adjusts the timing of transmitting the eCPRI signal from the second master station 210 so that the wireless transmission timing of the first slave station 120 is a predetermined timing. For example, when O-RAN is adopted as FH, the control unit 213 transmits an eCPRI signal within a transmission window (DL), which will be described later.

(5.3) Intermediate device 300
FIG. 7 is a functional block configuration diagram of the intermediate device 300. As described above, intermediate device 300 is an example of a communication device. As shown in FIG. 7, the intermediate device 300 includes a first communication section 310, a second communication section 320, a third communication section 330, and a control section 340.

The first communication unit 310 performs communication of a CPRI signal based on CPRI with the first master station 110.

The second communication unit 320 communicates eCPRI signals based on eCPRI with the second master station 210.

The third communication unit 330 communicates with the first slave station 120 using a CPRI signal based on CPRI.

The control unit 340 executes a conversion process between a CPRI signal compliant with CPRI and an eCPRI signal compliant with eCPRI. Specifically, the control unit 340 converts the eCPRI signal received from the second master station 210 into a CPRI signal, and converts the CPRI signal received from the first slave station 120 into an eCPRI signal. As mentioned above, the conversion process may include IFFT or FFT. The conversion process may include a process of converting the format. The control unit 340 may perform a combination process or a separation process.

In the embodiment, the control unit 340 transmits the eCPRI signal (CPRI signal after conversion processing) received from the second master station to the first slave station based on the delay time between the intermediate device 300 and the first slave station 120. 120 (hereinafter referred to as DL adjustment processing). The control unit 340 executes adjustment processing (hereinafter referred to as UL adjustment processing) for adjusting the timing of transmitting the CPRI signal (eCPRI signal after conversion processing) received from the first slave station to the second master station 210. The control unit 340 may execute at least one of the DL adjustment process and the UL adjustment process.

(6) Delay time Next, the delay time between the first master station 110 and the first slave station 120 will be explained. Although the delay time regarding the second master station 210 will be described later, the transmission delay time between the intermediate device 300 and the first slave station 120 and the processing delay time of the first slave station 120 are common.

As shown in FIG. 8, the DL delay time is the transmission delay time _T1 between the first master station 110 and the intermediate device 300, the processing delay time T _E1 of the intermediate device 300, and the It includes a transmission delay time T ₂ with the slave station 120 and a processing delay time T _E2 of the first slave station 120.

The UL delay time is the processing delay time T _E3 of the first slave station 120, the transmission delay time _T3 between the intermediate device 300 and the first slave station 120, the processing delay time T _E4 of the intermediate device 300, The transmission delay time T ₄ between the first master station 110 and the intermediate device 300 is included.

In FIG. 8, T _{off_A} is the time until the HFN of the DL signal received by the intermediate device 300 from the first master station 110 is reflected in the UL signal transmitted from the intermediate device 300 to the first master station 110. T _{off_B} is the time until the HFN of the DL signal transmitted by the first slave station 120 from the intermediate device 300 is reflected in the UL signal transmitted from the first slave station 120 to the intermediate device 300.

Here, with CPRI, although it is possible to measure the delay time between nodes that terminate the CPRI, it is not possible to measure the delay time beyond the node that terminates the CPRI. Therefore, the first master station 110 cannot measure T ₂ , T _E2 , T _E3 , T ₃ , T _{off_B} , etc. Under this background, each node performs the following operations.

First, the intermediate device 300 requests the first slave station 120 to report the delay time. The first slave station 120 reports T _E2 , T _E3 , and T _{off_B} to the intermediate device 300 . Since T _E2 and T _E3 can be considered to be the same value, only one of T _E2 and T _E3 may be reported.

Second, the intermediate device 300 calculates the time T until the HFN of the DL signal transmitted from the intermediate device 300 to the first slave station 120 is reflected in the UL signal transmitted from the first slave station 120 to the intermediate device 300. Measure. T has the relationship T=T ₂ +T _{off_B} +T ₃ .

Third, intermediate device 300 calculates T ₂ (T ₃ ). Here, since the DL transmission route and the UL transmission route are the same between the intermediate device 300 and the first slave station 120, it is possible to consider that T ₂ and T ₃ are the same value. . Therefore, the intermediate device 300 can calculate T ₂ (T ₃ ) using the formula T ₂ (T ₃ )=(TT _{off_B} )/2.

Fourth, the first master station 110 requests the intermediate device 300 to report the delay time between the intermediate device 300 and the first slave station 120. The intermediate device 300 reports T _E2 , T _E3 , and T _{off_B} to the first master station 110 .

Fifth, the intermediate device 300 sets T _{off_A} . T _{off_A} is expressed by the formula T _{off_A} =T _E1 +T ₂ +T _{off_B} +T ₃ +T _E4 .

Sixth, the first master station 110 determines the time required for the HFN of the DL signal transmitted from the first master station 110 to the intermediate device 300 to be reflected in the UL signal transmitted from the intermediate device 300 to the first master station 110. Measure T'. T' has the relationship T'=T ₁ +T _{off_A} +T ₄ .

Seventh, the first master station 110 calculates the transmission delay time between the first master station 110 and the first slave station 120. Note that the transmission delay time is considered to include the processing delay time of the intermediate device 300. Since the DL transmission path and the UL transmission path between the first master station 110 and the intermediate device 300 are the same, T ₁ and T ₄ can be considered to be the same value. Therefore, the transmission delay time is T ₁ +T _E1 +T ₂ (T ₃ +T _E4 +T ₄ ). Since T _{off_B} is reported from the intermediate device 300, the first master station 110 uses the formula T ₁ +T _E1 +T ₂ (T ₃ +T _E4 +T ₄ )=(T'-T _{off_B} )/2. Accordingly, it is possible to calculate T ₁ +T _E1 +T ₂ (T ₃ +T _E3 +T ₄ ).

Eighth, the first master station 110 calculates T ₁ +T _E1 +T ₂ +T _E2 (T _E3 +T ₃ +T _E4 +T ₄ ). T _E3 (T _E4 ) is reported from the intermediate device 300 and is therefore known.

Note that in the above example, a case was explained in which the intermediate device 300 does not report T _{off_A} to the first master station 110; however, the intermediate device 300 reports T _{off_A} to the first master _{station 110} , and T _{off_A} (synonymous with T _E3 +T ₃ +T _E4 and T _{off_A} ). In such a case, the first master station 110 can calculate T ₁ (T ₄ ) using the formula T ₁ (T ₄ )=(T'-T _{off_A} )/2. With such a configuration, the first master station 110 may calculate T ₁ +T _E1 +T ₂ +T _E2 (T _E3 +T ₃ +T _E4 +T ₄ ).

(7) Adjustment Process (7.1) DL Adjustment Process First, the DL delay profile in O-RAN will be explained. In the following, "max" means the maximum value and "min" means the minimum value. Furthermore, the time t at which wireless transmission is performed using the O-RU antenna is represented by "0".

As shown in FIG. 9, in DL in O-RAN, the Transmission window (DL) of O-DU 210 and the Reception window (DL) of O-RU 220 are determined as follows.

The transmission window (DL) of the O-DU 210 can be defined by parameters (T1a_min_up, T1a_max_up). Transmission window (DL) can be expressed by the difference between T1a_max_up and T1a_min_up. The parameters (T1a_min_up, T1a_max_up) may be interpreted as the measurement results from the output at the O-DU port (R1) to the wireless transmission. The parameters (T1a_min_up, T1a_max_up) may be measured by a delay measurement message (Measured Transport Method).

On the other hand, the Reception window (DL) of the O-RU 220 can be defined by parameters (T2a_min_up, T2a_max_up). Reception window (DL) can be expressed by the difference between T2a_max_up and T2a_min_up. The parameters (T2a_min_up, T2a_max_up) may be interpreted as measurement results from reception at the O-RU port (R2) to wireless transmission. T2a_min_up and T2a_max_up are examples of O-RU delay profiles.

Here, as the above-mentioned FH delay parameter, a parameter (T12_min) indicating the difference between T1a_max_up and T2a_max_up may be defined in advance. As the FH delay parameter described above, a parameter (T12_max) indicating the difference between T1a_min_up and T2a_min_up may be defined in advance. FH delay parameters are managed by intermediate device 300. T12_min and T12_max may be determined for each O-RAN use case.

In addition, T12_min defines the minimum delay time (minimum distance) between O-DU110 and O-RU120, and T12_max defines the maximum delay time (maximum distance) between O-DU110 and O-RU120. You may think that you are doing so.

Under such a premise, T1a_min_up that defines the transmission window (DL) only needs to satisfy the condition that the value is greater than or equal to T2a_min_up+T12_max for the O-RU 220 located on the air side of the O-DU 210. T1a_max_up, which defines the transmission window (DL), only needs to satisfy the condition that the value is equal to or less than T2a_max_up+T12_min for the O-RU 220 located on the air side of the O-DU 210. Intermediate device 300 determines window parameters to satisfy these conditions (window conditions). Alternatively, the O-DU 210 sets the transmission window (DL) to satisfy the window conditions.

In this way, the transmission window (DL) can be defined by the O-RU delay profile (T2a_min_up, T2a_max_up) and the FH delay parameters (T12_min, T12_max). The window parameters may include T1a_min_up and T1a_max_up.

In the embodiment, a case is assumed in which the intermediate device 300 and the first slave station 120 function as the O-RU 220, but the first slave station 120 does not support the above-mentioned Reception window (DL). Therefore, it is necessary to adjust the timing of transmitting the CPRI signal (eCPRI signal after conversion processing) from the intermediate device 300 to the first slave station 120.

Furthermore, the position where the intermediate device 300 is placed between the second master station 210 and the first slave station 120 is variable, and the reception window (DL) of the O-RU 220 described above can be applied as is to the intermediate device 300. I can't. For example, in a case where the intermediate device 300 is placed near the second master station 210, if the Reception window (DL) of the O-RU 220 described above is used, the eCPRI signal is transmitted from the second master station 210, and then the eCPRI signal is The time until a CPRI signal corresponding to 1 is transmitted from the first slave station 120 does not fall within T1a_max_up.

Therefore, the intermediate device 300 according to the embodiment executes the DL timing adjustment described below.

First, based on the delay time between the intermediate device 300 and the first slave station 120, the intermediate device 300 converts the CPRI signal after conversion processing into the first eCPRI signal transmitted from the second master station 210. The timing of transmission to the slave station 120 is adjusted. Specifically, the intermediate device 300 transmits the converted CPRI signal at a timing earlier than time t=0 by the delay time. According to such a configuration, the eCPRI signal (CPRI signal after conversion ) can be transmitted from the first slave station 120.

As shown in FIG. 10, the delay time includes at least the transmission delay time (T ₂ described above) between the intermediate device 300 and the first slave station 120. The delay time may further include the processing delay time ( _TE2 described above) of the first slave station 120. The delay time may further include at least a portion ( _{TE_NR2} in FIG. 10) of the processing delay time (T _E1 described above) of the intermediate device 300. For example, the delay time may be T _E2 +T ₂ +T _{E_NR2} .

Note that although FIG. 10 exemplifies a case where the processing delay time (T _E2 ) of the first slave station 120 is the same as T2a_min_up shown in FIG. 9, the processing delay time (T _{E2 )} of the first slave station 120 is ) may be longer than T2a_min_up shown in FIG. The processing delay time (T _E3 ) of the first slave station 120 may be shorter than T2a_max_up shown in FIG. 9 .

Here, T _{E_NR1} included in T _E1 may include the time required for the above-mentioned IFFT. T _{E_NR2} included in T _E1 may include the time required for the above-described combining process. As explained in FIG. 8, T _E2 and T ₂ can be specified by the intermediate device 300, and T _{E_NR1} and T _{E_NR2} are known to the intermediate device 300.

Second, the intermediate device 300 determines the reception window (in FIG. 10, Reception window (DL )'). Specifically, the intermediate device 300 changes the size of the Reception window (DL) shown in FIG. 9. The intermediate device 300 may set Reception window(DL)-T ₂ (namely, {(T2a_max_up-T2a_min_up)-T ₂ }) shown in FIG. 9 as Reception window(DL)'. Along with this, T2a_min_up' may be set in the intermediate device 300 as T2a_min_up, and T12_max' may be set in the intermediate device 300 as T12_max.

In such a case, an adjustment unit 303 (for example, a delay buffer, etc.) that performs DL adjustment processing may be provided between the IFFT processing unit 302 and the multiplexer 301. The IFFT processing section 302 and the adjustment section 303 may be part of the control section 340 described above.

(7.2) UL adjustment processing First, the UL delay profile in O-RAN will be explained. In the following, "max" means the maximum value and "min" means the minimum value. Furthermore, the time t at which reception is performed by the O-RU antenna is represented by "0".

As shown in FIG. 11, in UL in O-RAN, the Transmission window (UL) of O-RU 220 and the Reception window (UL) of O-DU 210 are defined as follows.

The transmission window (UL) of O-RU220 can be defined by parameters (Ta3_min, Ta3_max). That is, the transmission window (UL) can be expressed by the difference between Ta3_max and Ta3_min. The parameters (Ta3_min, Ta3_max) may be interpreted as the measurement results from reception at the O-RU antenna to output at the O-RU port (R3). Ta3_min and Ta3_max are examples of O-RU delay profiles.

On the other hand, the Reception window (UL) of the O-DU 210 can be defined by parameters (Ta4_min, Ta4_max). That is, the Reception window (UL) can be expressed by the difference between Ta4_max and Ta4_min. The parameters (Ta4_min, Ta4_max) may be interpreted as the measurement results from reception at the O-RU antenna to reception at the O-DU port (R4). The parameters (Ta4_min, Ta4_max) may be measured by a delay measurement message (Measured Transport Method).

Here, as the above-mentioned FH delay parameter, a parameter (T34_min) indicating the difference between Ta4_min and Ta3_min may be defined in advance. As the FH delay parameter described above, a parameter (T34_max) indicating the difference between Ta4_max and Ta3_max may be defined in advance. FH delay parameters are managed by intermediate device 300. T34_min and T34_max may be determined for each O-RAN use case.

In addition, T34_min defines the minimum delay time (minimum distance) between O-DU110 and O-RU120, and T34_max defines the maximum delay time (maximum distance) between O-DU110 and O-RU120. You may think that you are doing so.

Under such a premise, Ta4_min that defines the reception window (UL) only needs to satisfy the condition that the value is equal to or less than Ta3_min+T34_min for the O-RU 220 located on the air side of the O-DU 210. Ta4_max that defines the reception window (UL) only needs to satisfy the condition that the value is greater than or equal to Ta3_max+T34_max for the O-RU220 that exists on the air side than the O-DU210. Intermediate device 300 determines window parameters to satisfy these conditions (window conditions). Alternatively, the O-DU 210 sets the Reception window (UL) to satisfy the window conditions.

In this way, the Reception window (UL) can be defined by the O-RU delay profile (Ta3_min, Ta3_max) and the FH delay parameters (T34_min, T34_max). The window parameters may include Ta4_min and Ta4_max.

In the embodiment, a case is assumed in which the intermediate device 300 and the first slave station 120 function as the O-RU 220, but the first slave station 120 does not support the above-mentioned transmission window (UL). Therefore, it is necessary to adjust the timing of transmitting the eCPRI signal (CPRI signal after conversion processing) from the intermediate device 300 to the second master station 210.

Therefore, the intermediate device 300 according to the embodiment performs the UL timing adjustment described below.

First, based on the delay time between the intermediate device 300 and the first slave station 120, the intermediate device 300 converts the converted eCPRI signal into the second slave station with respect to the CPRI signal transmitted from the first slave station 120. Adjust the timing of transmission to the master station 210. Specifically, intermediate device 300 transmits the converted CPRI signal at a timing later than time t=0 by the delay time.

As shown in FIG. 12, the delay time includes at least the transmission delay time (T ₃ described above) between the intermediate device 300 and the first slave station 120. The delay time does not need to include the processing delay time (T _E3 described above) of the first slave station 120. The delay time does not need to include the processing delay time (T _E4 described above) of the intermediate device 300. For example, the delay time may be _T3 . The processing delay time (T _E4 described above) of the intermediate device 300 only needs to satisfy the condition that it is a value equal to or less than Ta3_max-Ta3_min.

Note that although FIG. 12 illustrates a case where the processing delay time (T _E3 ) of the first slave station 120 is the same as Ta3_min, the processing delay time (T _E3 ) of the first slave station 120 is greater than Ta3_min. It can be long. The processing delay time ( _TE3 ) of the first slave station 120 may be shorter than Ta3_max.

Here, T _{E_NR3} included in T _E4 may include the time necessary for the above-mentioned separation process. T _{E_NR4} included in T _E4 may include the time required for the above-mentioned FFT. As explained in FIG. 8, T ₃ can be specified by the intermediate device 300, and T _{E_NR3} and T _{E_NR4} are known to the intermediate device 300.

Second, based on the delay time between the intermediate device 300 and the first slave station 120, the intermediate device 300 determines the transmission window (in FIG. )'). Specifically, the intermediate device 300 shifts the transmission window (UL) shown in FIG. 9 in the time axis direction. The intermediate device 300 may set Transmission window(UL)+T ₃ as Transmission window(UL)'.

In such a case, the adjustment unit 306 (eg, delay buffer, etc.) that executes the UL adjustment process may be provided closer to the second master station 210 than the FFT processing unit 305. The FFT processing section 305 and the adjustment section 306 may be part of the control section 340 described above.

Note that in the UL adjustment process, unlike the DL adjustment process, the idea is that timing adjustment is performed by the intermediate device 300 without changing the Reception window (UL) used between the second master station 210 and the second slave station 220. Based on this, the reception window (UL) used between the second master station 210 and the second slave station 220 can be used without changing.

(8) Actions and Effects In the embodiment, by newly introducing the concept of the intermediate device 300, it is possible to quickly expand the NR coverage area by using the existing first slave station 120.

In the embodiment, the intermediate device 300 executes at least one of the DL adjustment process and the UL adjustment process based on the delay time between the intermediate device 300 and the first slave station 120. According to such a configuration, the eCPRI signal (CPRI signal after conversion processing) received from the second master station 210 can be transmitted to the first slave station 120 at an appropriate timing, or The CPRI signal (eCPRI signal after conversion processing) received from the eCPRI signal can be transmitted to the second master station 210 at an appropriate timing.

[Change example 1]
Modification example 1 of the embodiment will be described below. In the following, differences from the embodiment will be mainly explained.

In the embodiment, the timing of transmitting a signal from the first slave station 120 to the second master station 210 and the timing of transmitting a signal from the second master station 210 to the first slave station 120 have been described. On the other hand, in modification example 1, the timing of transmitting a signal from the first master station 110 to the first slave station 120 will be described.

As described above, it is necessary to adjust the timing of transmitting the CPRI signal from the first master station 110 so that the wireless transmission timing of the first slave station 120 is a predetermined timing. However, as explained in FIG. 8, with CPRI, although it is possible to measure delay time between nodes terminating CPRI, it is not possible to measure delay time beyond the node terminating CPRI. Therefore, each node performs the operations shown in FIG.

As shown in FIG. 13, in step S10, the intermediate device 300 requests the first slave station 120 to report the delay time.

In step S11, the first slave station 120 reports T _E2 , T _E3 and T _{off_B} to the intermediate device 300. Since T _E2 and T _E3 can be considered to be the same value, only one of T _E2 and T _E3 may be reported.

In step S12, the intermediate device 300 estimates the time T until the HFN of the DL signal transmitted from the intermediate device 300 to the first slave station 120 is reflected in the UL signal transmitted from the first slave station 120 to the intermediate device 300. Measure. T has the relationship T=T ₂ +T _{off_B} +T ₃ .

In step S13, the intermediate device 300 calculates T ₂ (T ₃ ). Here, since the DL transmission route and the UL transmission route are the same between the intermediate device 300 and the first slave station 120, it is possible to consider that T ₂ and T ₃ are the same value. . Therefore, the intermediate device 300 can calculate T ₂ (T ₃ ) using the formula T ₂ (T ₃ )=(TT _{off_B} )/2.

In step S14, the first master station 110 requests the intermediate device 300 to report the delay time between the intermediate device 300 and the first slave station 120.

In step S15, the intermediate device 300 executes a reporting process to report T _E2 , T _E3 , and T _{off_B} to the first master station 110. As in step S11, since T _E2 and T _E3 can be considered to be the same value, only one of T _E2 and T _E3 may be reported. Here, T _E2 (T _E3 ) and T _{off_B} are examples of information elements for specifying the delay time between the intermediate device 300 and the first slave station 120. In detail, T _E2 (T _E3 ) is an example of an information element for specifying the processing delay time of the first slave station 120. T _{off_B} is an example of an information element for specifying the transmission delay time between the intermediate device 300 and the first slave station 120.

In step S16, the intermediate device 300 sets T _{off_A} . T _{off_A} is expressed by the formula T _{off_A} =T _E1 +T ₂ +T _{off_B} +T ₃ +T _E4 .

In step S17, the first master station 110 determines the time required for the HFN of the DL signal transmitted from the first master station 110 to the intermediate device 300 to be reflected in the UL signal transmitted from the intermediate device 300 to the first master station 110. Measure T'. T' has the relationship T'=T ₁ +T _{off_A} +T ₄ .

In step S18, the first master station 110 calculates the transmission delay time between the first master station 110 and the first slave station 120. Note that the transmission delay time is considered to include the processing delay time of the intermediate device 300. Since the DL transmission path and the UL transmission path between the first master station 110 and the intermediate device 300 are the same, T ₁ and T ₄ can be considered to be the same value. Therefore, the transmission delay time is T ₁ +T _E1 +T ₂ (T ₃ +T _E4 +T ₄ ). Since T _{off_B} is reported from the intermediate device 300, the first master station 110 uses the formula T ₁ +T _E1 +T ₂ (T ₃ +T _E4 +T ₄ )=(T'-T _{off_B} )/2. Accordingly, it is possible to calculate T ₁ +T _E1 +T ₂ (T ₃ +T _E3 +T ₄ ). Next, the first master station 110 calculates T ₁ +T _E1 +T ₂ +T _E2 (T _E3 +T ₃ +T _E4 +T ₄ ). T _E3 (T _E4 ) is reported from the intermediate device 300 and is therefore known.

In step S19, the first master station 110 transmits the CPRI signal at a timing earlier than the predetermined timing by the delay time based on the delay time between the first master station 110 and the first slave station 120. The delay time is T ₁ +T _E1 +T ₂ +T _E2 (T _E3 +T ₃ +T _E4 +T ₄ ).

In FIG. 13, a case has been described in which the intermediate device 300 does not report T _{off_A} to the first master station 110, but the intermediate device 300 reports T _E1 +T ₂ +T _E2 and T _{off_A} to the first master station 110. (synonymous with T _E3 +T ₃ +T _E4 and T _{off_A} ) may be reported. In such a case, the first master station 110 can calculate T ₁ (T ₄ ) using the formula T ₁ (T ₄ )=(T'-T _{off_A} )/2. With this configuration, the first master station 110 is earlier than the predetermined timing by the delay time (here, T ₁ +T _E1 +T ₂ +T _E2 (T _E3 +T ₃ +T _E4 +T ₄ )). The CPRI signal may be transmitted at the same time. Note that when the intermediate device 300 and the first slave station 120 are considered as the first slave station, T _E1 , T ₂ and T _E2 (T _E3 +T ₃ +T _E4 ) are the processing delays of the first slave station. You can think of it as time. T _E1 +T ₂ +T _E2 (T _E3 +T ₃ +T _E4 ) can be considered to be an example of an information element for specifying the delay time between the intermediate device 300 and the first slave station 120. good.

(action and effect)
In modification example 1, the intermediate device 300 executes a reporting process to report information elements for specifying the delay time between the intermediate device 300 and the first slave station 120 to the first master station 110. According to such a configuration, the first master station 110 can transmit the CPRI signal from the first master station 110 at an appropriate timing so that the wireless transmission timing of the first slave station 120 is at the predetermined timing. .

[Change example 2]
Modification example 2 of the embodiment will be described below. In the following, differences from the embodiment will be mainly explained.

In modification example 2, variations in the combining process of the signal received from the first master station 110 and the signal received from the second master station 210 and the separation process of the signal received from the first slave station will be described.

First, a case will be described in which the intermediate device 300 does not handle the CPRI signal addressed to the first master station 110 and the eCPRI signal addressed to the second master station separately.

As shown in the upper part (DL) of FIG. 14, the processing unit 381 of the intermediate device 300 executes format conversion of the CPRI signal received from the first master station 110, and inputs the CPRI signal compliant with CPRI to the multiplexer 301. . On the other hand, the processing unit 382 of the intermediate device 300 executes IFFT and format conversion of the eCPRI signal received from the second master station 210, and inputs the CPRI signal compliant with CPRI to the multiplexer 301. The multiplexer 301 combines the CPRI signal input from the processing section 381 and the CPRI signal input from the processing section 382, and outputs the combined CPRI signal.

On the other hand, as shown in the lower part (UL) of FIG. 14, the demultiplexer 301 of the intermediate device 300 inputs the CPRI signal received from the first slave station 120 to the processing unit 383, and receives the CPRI signal from the first slave station 120. The CPRI signal is input to the processing section 384. The demultiplexer 301 only has the function of branching the CPRI signal received from the first slave station 120 into two systems, and the CPRI signal input to the processing unit 383 and the processing unit 384 is It may also be the CPRI signal itself received from 120. The processing unit 383 executes format conversion of the CPRI signal input from the demultiplexer 301, and outputs a CPRI signal conforming to CPRI. The processing unit 384 performs FFT and format conversion on the CPRI signal input from the demultiplexer 301, and outputs an eCPRI signal compliant with eCPRI.

In such a case, the first master station 110 extracts the CPRI signal addressed to the first master station 110 from among the CPRI signals output from the intermediate device 300, and processes the extracted CPRI signal. Similarly, the first master station 110 extracts the eCPRI signal addressed to the first master station 110 from among the eCPRI signals output from the intermediate device 300, and processes the extracted eCPRI signal.

Note that the multiplexer (demultiplexer) 301, the processing section 381, the processing section 382, the processing section 383, and the processing section 384 may be part of the control section 340 described above.

Second, a case will be described in which the intermediate device 300 separately handles the CPRI signal addressed to the first master station 110 and the eCPRI signal addressed to the second master station.

As shown in the upper part (DL) of FIG. 15, the processing unit 391 of the intermediate device 300, like the processing unit 381, converts the format of the CPRI signal received from the first master station 110, The signal is input to multiplexer 301. On the other hand, similarly to the processing unit 382, the processing unit 392 of the intermediate device 300 executes IFFT and format conversion of the eCPRI signal received from the second master station 210, and inputs the CPRI signal compliant with CPRI to the multiplexer 301. . The multiplexer 301 combines the CPRI signal input from the processing section 391 and the CPRI signal input from the processing section 392, and outputs the combined CPRI signal.

On the other hand, as shown in the lower part (UL) of FIG. 15, the demultiplexer 301 of the intermediate device 300 inputs the CPRI signal received from the first slave station 120 to the processing unit 393, and receives the CPRI signal from the first slave station 120. The CPRI signal is input to the extraction & processing section 394. The demultiplexer 301 only has the function of branching the CPRI signal received from the first slave station 120 into two systems, and the CPRI signal input to the processing unit 393 and the processing unit 394 is transmitted to the first slave station. It may also be the CPRI signal itself received from 120. The processing unit 393 extracts the CPRI signal of the first band (for example, LTE band) corresponding to the first master station 110 from among the CPRI signals input from the demultiplexer 301, and converts the extracted CPRI into a format. Executes and outputs a CPRI signal that complies with CPRI. The processing unit 394 extracts a CPRI signal of a second band (for example, NR band) corresponding to the second master station 210 from among the CPRI signals input from the demultiplexer 301, and extracts the FFT and format of the extracted CPRI. Performs the conversion and outputs an eCPRI signal that is compliant with eCPRI.

Note that the multiplexer (demultiplexer) 301, the processing section 391, the processing section 392, the processing section 393, and the processing section 394 may be part of the control section 340 described above.

Here, in the configuration shown in FIG. 15, the first band (for example, LTE band) corresponding to the first master station 110 and the second band (for example, NR band) corresponding to the second master station 210 may be different. It may be a premise. When at least a portion of the first band and the second band overlap, the configuration shown in FIG. 14 may be adopted.

(action and effect)
In modification example 2, the intermediate device 300 transmits the CPRI signal received from the first master station 110 and the eCPRI signal received from the second master station 210 to the first slave station 120 as a CPRI signal conforming to CPRI. According to such a configuration, it is possible to expand the NR coverage area by using the first slave station 120 that is not compliant with eCPRI.

[Change example 3]
Modification example 3 of the embodiment will be described below. In the following, differences from the embodiment will be mainly explained.

In modification example 3, a case will be described in which DSS (Dynamic Spectrum Sharing) is applied to share the band between the first master station 110 and the second master station 210. In DSS, RB (Resource Block) may be shared. The configuration shown in FIG. 14 may be used for the synthesis process and the separation process.

For example, in DSS, as shown in FIG. 16, in units defined by frequency and time (for example, subframes), the RB used by the first master station 110 (hereinafter referred to as RB (LTE)) and the second master station RBs are allocated so that the RBs used by the station 210 (hereinafter referred to as RBs (NR)) do not overlap. For example, the second base station 210 receives information indicating the RB (LTE) from the first base station 110, and executes resource allocation using the RB other than the RB (LTE). Therefore, in the process of combining the CPRI signal received from the first master station 110 and the eCPRI signal (CPRI signal after conversion processing) received from the second master station 210, the intermediate device 300 suppresses interference between these signals. It is necessary to synchronize these signals.

Under such a background, the first base station 110 adds subframe number information (hereinafter referred to as SFN information) to a field included in the CPRI signal, and transmits the CPRI signal to which the SFN information is added. The field to which SFN information is added may be a field in which a base station frame number (BFN; Node B Frame Number) corresponding to the first master station 110 is stored.

On the other hand, the second master station 210 transmits an eCPRI signal including an information element for identifying the SFN. The information element may include C-plane information such as Start Symbol ID. Start Symbol ID is a parameter that identifies the number of the first symbol included in the slot. The information element may include a delay management parameter. The delay management parameters are parameters such as T12_min, T12_max, T34_min, T34_max, T2a_max_up, T2a_min_up, T3a_min, and T3a_max described above.

Intermediate device 300 identifies the SFN corresponding to first base station 110 based on SNF information added to a field (for example, BFN field) included in the CPRI signal received from first base station 110. The intermediate device identifies the SFN corresponding to the second master station 210 based on information elements (eg, Start Symbol ID and delay management parameter) included in the eCPRI signal received from the second master station 210. The intermediate device 300 receives the CPRI signal received from the first master station 110 and the eCPRI signal received from the second master station 210 (based on the SFN corresponding to the first master station 110 and the SFN corresponding to the second master station 210). Executes synchronization processing to synchronize with the CPRI signal (after conversion processing).

For example, as shown in FIG. 17, in step S30, the first master station 110 and the second master station 210 receive reference time information. Although not particularly limited, the reference time information may be time information using GPS (Global Positioning System) or time information using PTP (Precision Time Protocol).

In step S31, the first master station 110 adds SFN information to a field (for example, BFN field) included in the CPRI signal, and transmits the CPRI signal to which the SFN information is added.

In step S32, the second master station 210 transmits an eCPRI signal including information elements (for example, Start Symbol ID and delay management parameter) for identifying the SFN.

In step S33, the intermediate device 300 determines the CPRI signal received from the first base station 110 and the CPRI signal received from the second base station 210 based on the SFN corresponding to the first base station 110 and the SFN corresponding to the second base station 210. Executes synchronization processing to synchronize with the eCPRI signal (CPRI signal after conversion processing). The intermediate device 300 executes a combining process of combining the CPRI signal received from the first master station 110 and the eCPRI signal (CPRI signal after conversion processing) received from the second master station 210.

In step S34, the intermediate device 300 transmits the combined CPRI signal to the first slave station 120.

(action and effect)
In modification example 3, the intermediate device 300 identifies the SFN of the first base station 110 based on the SFN information included in the field included in the CPRI signal, and identifies the SFN of the second base station based on the information element included in the eCPRI signal. Identify SFN. The intermediate device 300 performs a synchronization process to synchronize the CPRI signal received from the first master station 110 and the eCPRI signal (CPRI signal after conversion processing) received from the second master station 210 based on the identified SFN. Execute. According to such a configuration, DSS can be operated appropriately.

[Change example 4]
Modification example 4 of the embodiment will be described below. In the following, differences from the embodiment will be mainly explained.

In the embodiment, the intermediate device 300 has an operating mode that corresponds to both the first master station 110 and the second master station 210. On the other hand, in modification example 4, the intermediate device 300 operates in a first operation mode in which control is executed corresponding to the first master station 110, and in a first operation mode in which control is executed corresponding to the first master station 110 and the second master station 210. 2 operational modes, and a third operational mode in which control corresponding to the second master station 210 is executed.

The first operation mode may be an operation mode applied to a case where the intermediate device 300 is connected to the first master station 110 but not connected to the second master station 210. The first operation mode may be referred to as LTE-only operation mode. In such a case, the intermediate device 300 may relay the CPRI signal received from the first master station 110 to the first slave station 120. For example, intermediate device 300 functions as an optical signal relay device. However, the intermediate device 300 may have the functions described in the above-mentioned modification example 1.

The second operation mode is an operation mode applied to a case where the intermediate device 300 is connected to both the first master station 110 and the second master station 210. The second operation mode may be called LTE/NR operation mode. In such a case, the relay device 300 may have one or more functions selected from the functions described in the embodiment and modified examples 1 to 3.

The third operation mode may be an operation mode applied to a case where the intermediate device 300 is connected to both the first master station 110 and the second master station 210. The third operation mode may be an operation mode applied to a case where the intermediate device 300 is connected to the second master station 210, but the intermediate device 300 is not connected to the first master station 110. The third operation mode may be called NR sole operation mode. In such a case, the intermediate device 300 only needs to have the function of executing the adjustment processing (DL adjustment processing and UL adjustment processing) described in the embodiment. Note that if the intermediate device 300 is used in the third operation mode from the beginning,
For example, the first operation mode is an operation mode that is applied before connecting the second master station 210 to the intermediate device 300, that is, at the stage of introducing the intermediate device 300 for the purpose of expanding the NR coverage area. Good too. The second operation mode may be an operation mode applied at the stage when the second master station 210 is connected to the intermediate device 300 for the purpose of expanding the NR coverage area. The third operation mode may be an operation mode applied when the first slave station 120 finishes its role as an LTE slave station.

Note that in such a case where the third operation mode may be applied from the beginning of introducing the intermediate device 300, the intermediate device 300 does not need to have the first communication unit 310 described above.

[Other embodiments]
In the above-mentioned disclosure, the embodiment and modifications 1 to 4 have been described separately, but it is only necessary to provide one or more functions selected from the functions described in the embodiment and modifications 1 to 4. . Such functionality may be provided as a method.

Although the present invention has been described above with reference to Examples, it is obvious to those skilled in the art that the present invention is not limited to these descriptions and that various modifications and improvements can be made.

The block diagrams (FIGS. 5 to 7) used to explain the embodiments described above show blocks in functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using one physically or logically coupled device, or may be realized using two or more physically or logically separated devices directly or indirectly (e.g. , wired, wireless, etc.) and may be realized using a plurality of these devices. The functional block may be realized by combining software with the one device or the plurality of devices.

Functions include judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, These include, but are not limited to, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assigning. I can't. For example, a functional block (configuration unit) that performs transmission is called a transmitting unit or a transmitter. In either case, as described above, the implementation method is not particularly limited.

Furthermore, the first master station 110, the second master station 210, and the intermediate device 300 (the device) may function as a computer that performs processing of the wireless communication method of the present disclosure. FIG. 18 is a diagram showing an example of the hardware configuration of the device. As shown in FIG. 13, the device may be configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

In addition, in the following description, the word "apparatus" can be read as a circuit, a device, a unit, etc. The hardware configuration of the device may include one or more of the devices shown in the figure, or may not include some of the devices.

Each functional block of the device (see FIGS. 5 and 6) is realized by any hardware element of the computer device or a combination of hardware elements.

In addition, each function in the device is performed by loading predetermined software (programs) onto hardware such as the processor 1001 and memory 1002, so that the processor 1001 performs calculations, controls communication by the communication device 1004, and controls the memory This is realized by controlling at least one of data reading and writing in the storage 1002 and the storage 1003.

The processor 1001, for example, operates an operating system to control the entire computer. The processor 1001 may be configured by a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, registers, and the like.

Furthermore, the processor 1001 reads programs (program codes), software modules, data, and the like from at least one of the storage 1003 and the communication device 1004 to the memory 1002, and executes various processes in accordance with these. As the program, a program that causes a computer to execute at least part of the operations described in the above embodiments is used. Further, the various processes described above may be executed by one processor 1001, or may be executed by two or more processors 1001 simultaneously or sequentially. Processor 1001 may be implemented by one or more chips. Note that the program may be transmitted from a network via a telecommunications line.

The memory 1002 is a computer-readable recording medium, and includes at least one of Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), Random Access Memory (RAM), etc. may be done. Memory 1002 may be called a register, cache, main memory, or the like. The memory 1002 can store programs (program codes), software modules, etc. that can execute a method according to an embodiment of the present disclosure.

The storage 1003 is a computer-readable recording medium, such as an optical disk such as a Compact Disc ROM (CD-ROM), a hard disk drive, a flexible disk, a magneto-optical disk (such as a compact disk, a digital versatile disk, or a Blu-ray disk). (registered trademark disk), smart card, flash memory (eg, card, stick, key drive), floppy disk, magnetic strip, etc. Storage 1003 may also be called auxiliary storage. The above-mentioned recording medium may be, for example, a database including at least one of memory 1002 and storage 1003, a server, or other suitable medium.

The communication device 1004 is hardware (transmission/reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, or the like.

The communication device 1004 includes, for example, a high frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). It may be composed of.

The input device 1005 is an input device (eg, keyboard, mouse, microphone, switch, button, sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that performs output to the outside. Note that the input device 1005 and the output device 1006 may have an integrated configuration (for example, a touch panel).

Further, each device such as the processor 1001 and the memory 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses for each device.

Furthermore, the device may include hardware such as a microprocessor, digital signal processor (DSP), application specific integrated circuit (ASIC), programmable logic device (PLD), and field programmable gate array (FPGA). A part or all of each functional block may be realized by the hardware. For example, processor 1001 may be implemented using at least one of these hardwares.

Furthermore, the notification of information is not limited to the aspects/embodiments described in this disclosure, and may be performed using other methods. For example, notification of information may be performed using physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), upper layer signaling (e.g., RRC signaling, Medium Access Control (MAC) signaling, broadcast information (Master Information Block), etc. (MIB), System Information Block (SIB)), other signals, or a combination thereof. RRC signaling may also be referred to as RRC messages, such as RRC Connection Setup (RRC Connection Setup). ) message, RRC Connection Reconfiguration message, etc.

Each aspect/embodiment described in this disclosure is applicable to Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system ( 5G), Future Radio Access (FRA), New Radio (NR), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)) , IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), and other suitable systems and next-generation systems extended based thereon. may be applied to. Furthermore, a combination of multiple systems (for example, a combination of at least one of LTE and LTE-A with 5G) may be applied.

The order of the processing procedures, sequences, flowcharts, etc. of each aspect/embodiment described in this disclosure may be changed as long as there is no contradiction. For example, the methods described in this disclosure use an example order to present elements of the various steps and are not limited to the particular order presented.

The specific operations performed by the base station in this disclosure may be performed by its upper node in some cases. In a network consisting of one or more network nodes including a base station, various operations performed for communication with a terminal are performed by the base station and other network nodes other than the base station (e.g., MME or It is clear that this can be done by at least one of the following: (conceivable, but not limited to) S-GW, etc.). Although the case where there is one network node other than the base station is illustrated above, it may be a combination of multiple other network nodes (for example, MME and S-GW).

Information, signals (information, etc.) may be output from an upper layer (or lower layer) to a lower layer (or upper layer). It may be input/output via multiple network nodes.

The input/output information may be stored in a specific location (for example, memory) or may be managed using a management table. Information that is input and output may be overwritten, updated, or additionally written. The output information may be deleted. The input information may be sent to other devices.

Judgment may be made using a value expressed by 1 bit (0 or 1), a truth value (Boolean: true or false), or a comparison of numerical values (for example, a predetermined value). (comparison with a value).

Each aspect/embodiment described in this disclosure may be used alone, may be used in combination, or may be switched and used in accordance with execution. In addition, notification of prescribed information (for example, notification of "X") is not limited to being done explicitly, but may also be done implicitly (for example, not notifying the prescribed information). Good too.

Software includes instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, whether referred to as software, firmware, middleware, microcode, hardware description language, or by any other name. , should be broadly construed to mean an application, software application, software package, routine, subroutine, object, executable, thread of execution, procedure, function, etc.

Additionally, software, instructions, information, etc. may be sent and received via a transmission medium. For example, if the software uses wired technology (coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), etc.) and/or wireless technology (infrared, microwave, etc.) to When transmitted from a server or other remote source, these wired and/or wireless technologies are included within the definition of transmission medium.

The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may refer to voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of the foregoing. It may also be represented by a combination of

Note that terms explained in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of the channel and the symbol may be a signal. Also, the signal may be a message. Furthermore, a component carrier (CC) may also be called a carrier frequency, cell, frequency carrier, or the like.

As used in this disclosure, the terms "system" and "network" are used interchangeably.

In addition, the information, parameters, etc. described in this disclosure may be expressed using absolute values, relative values from a predetermined value, or using other corresponding information. may be expressed. For example, radio resources may be indicated by an index.

The names used for the parameters described above are not restrictive in any respect. Furthermore, the mathematical formulas etc. using these parameters may differ from those explicitly disclosed in this disclosure. Since the various channels (e.g. PUCCH, PDCCH, etc.) and information elements can be identified by any suitable designation, the various names assigned to these various channels and information elements are in no way exclusive designations. isn't it.

In this disclosure, "Base Station (BS)," "wireless base station," "fixed station," "NodeB," "eNodeB (eNB)," "gNodeB (gNB)," " "access point", "transmission point", "reception point", "transmission/reception point", "cell", "sector", "cell group", " The terms "carrier", "component carrier", etc. may be used interchangeably. A base station is sometimes referred to by terms such as macrocell, small cell, femtocell, and picocell.

A base station can accommodate one or more (eg, three) cells (also called sectors). If a base station accommodates multiple cells, the overall coverage area of the base station can be partitioned into multiple smaller areas, and each smaller area is divided into base station subsystems (e.g., small indoor base stations (Remote Radio Communication services can also be provided by Head: RRH).

The term "cell" or "sector" refers to part or all of the coverage area of base stations and/or base station subsystems that provide communication services in this coverage.

In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably. .

A mobile station is defined by a person skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless It may also be referred to as a terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

At least one of a base station and a mobile station may be called a transmitting device, a receiving device, a communication device, or the like. Note that at least one of the base station and the mobile station may be a device mounted on a mobile body, the mobile body itself, or the like. The moving object may be a vehicle (for example, a car, an airplane, etc.), an unmanned moving object (for example, a drone, a self-driving car, etc.), or a robot (manned or unmanned). ). Note that at least one of the base station and the mobile station includes devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

Furthermore, the base station in the present disclosure may be read as a mobile station (user terminal, hereinafter the same). For example, communication between a base station and a mobile station is replaced with communication between multiple mobile stations (for example, it may be called Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.). Regarding the configuration, each aspect/embodiment of the present disclosure may be applied. In this case, the mobile station may have the functions that the base station has. Further, words such as "up" and "down" may be replaced with words corresponding to inter-terminal communication (for example, "side"). For example, uplink channels, downlink channels, etc. may be replaced with side channels.

Similarly, the mobile station in the present disclosure may be read as a base station. In this case, the base station may have the functions that the mobile station has.
A radio frame may be composed of one or more frames in the time domain. Each frame or frames in the time domain may be called a subframe.
A subframe may further be composed of one or more slots in the time domain. A subframe may have a fixed time length (eg, 1 ms) that does not depend on numerology.

Numerology may be a communication parameter applied to the transmission and/or reception of a signal or channel. Numerology includes, for example, subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame configuration, transmission and reception. It may also indicate at least one of a specific filtering process performed by the device in the frequency domain, a specific windowing process performed by the transceiver in the time domain, etc.

A slot may be composed of one or more symbols (Orthogonal Frequency Division Multiplexing (OFDM) symbols, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols, etc.) in the time domain. A slot may be a unit of time based on numerology.

A slot may include multiple minislots. Each minislot may be made up of one or more symbols in the time domain. Furthermore, a mini-slot may also be called a sub-slot. A minislot may be made up of fewer symbols than a slot. PDSCH (or PUSCH) transmitted in time units larger than minislots may be referred to as PDSCH (or PUSCH) mapping type A. PDSCH (or PUSCH) transmitted using minislots may be referred to as PDSCH (or PUSCH) mapping type B.

Radio frames, subframes, slots, minislots, and symbols all represent time units for transmitting signals. Other names may be used for the radio frame, subframe, slot, minislot, and symbol.

For example, one subframe may be referred to as a transmission time interval (TTI), multiple consecutive subframes may be referred to as a TTI, or one slot or minislot may be referred to as a TTI. In other words, at least one of the subframe and TTI may be a subframe (1ms) in existing LTE, a period shorter than 1ms (for example, 1-13 symbols), or a period longer than 1ms. It may be. Note that the unit representing TTI may be called a slot, minislot, etc. instead of a subframe.

Here, TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (frequency bandwidth, transmission power, etc. that can be used by each user terminal) to each user terminal on a TTI basis. Note that the definition of TTI is not limited to this.

The TTI may be a transmission time unit of a channel-coded data packet (transport block), a code block, a codeword, etc., or may be a processing unit of scheduling, link adaptation, etc. Note that when a TTI is given, the time interval (for example, the number of symbols) to which transport blocks, code blocks, code words, etc. are actually mapped may be shorter than the TTI.

Note that when one slot or one minislot is called a TTI, one or more TTIs (that is, one or more slots or one or more minislots) may be the minimum time unit for scheduling. Further, the number of slots (minislot number) that constitutes the minimum time unit of the scheduling may be controlled.

A TTI having a time length of 1 ms may be called a normal TTI (TTI in LTE Rel. 8-12), normal TTI, long TTI, normal subframe, normal subframe, long subframe, slot, etc. A TTI that is shorter than the normal TTI may be referred to as a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

Note that long TTI (e.g., normal TTI, subframe, etc.) may be read as TTI with a time length exceeding 1ms, and short TTI (e.g., shortened TTI, etc.) may be interpreted as TTI with a time length of less than the long TTI and 1ms. It may also be read as a TTI having a TTI length of the above length.

A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and may include one or more continuous subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of the new merology, and may be 12, for example. The number of subcarriers included in an RB may be determined based on newerology.

Additionally, the time domain of an RB may include one or more symbols and may be one slot, one minislot, one subframe, or one TTI long. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

Note that one or more RBs are classified into physical resource blocks (Physical RBs: PRBs), sub-carrier groups (SCGs), resource element groups (REGs), PRB pairs, RB pairs, etc. May be called.

Further, a resource block may be configured by one or more resource elements (RE). For example, 1 RE may be a radio resource region of 1 subcarrier and 1 symbol.

Bandwidth Part (BWP) (also called partial bandwidth, etc.) refers to a subset of contiguous common resource blocks (RBs) for a certain numerology in a certain carrier. good. Here, the common RB may be specified by an RB index based on a common reference point of the carrier. PRBs may be defined in a BWP and numbered within that BWP.

The BWP may include a BWP for UL (UL BWP) and a BWP for DL (DL BWP). One or more BWPs may be configured within one carrier for the UE.

At least one of the configured BWPs may be active and the UE may not assume to transmit or receive a given signal/channel outside of the active BWP. Note that "cell", "carrier", etc. in the present disclosure may be replaced with "BWP".

The structures of radio frames, subframes, slots, minislots, symbols, etc. described above are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of symbols included in an RB, The number of subcarriers, the number of symbols within a TTI, the symbol length, the cyclic prefix (CP) length, and other configurations can be changed in various ways.

The terms "connected", "coupled", or any variations thereof, refer to any connection or coupling, direct or indirect, between two or more elements and to each other. It can include the presence of one or more intermediate elements between two elements that are "connected" or "coupled." The bonds or connections between elements may be physical, logical, or a combination thereof. For example, "connection" may be replaced with "access." As used in this disclosure, two elements may include one or more electrical wires, cables, and/or printed electrical connections, as well as in the radio frequency domain, as some non-limiting and non-inclusive examples. , electromagnetic energy having wavelengths in the microwave and optical (both visible and non-visible) ranges, and the like.

The reference signal may also be abbreviated as Reference Signal (RS), and may be called a pilot depending on the applicable standard.

As used in this disclosure, the phrase "based on" does not mean "based solely on" unless explicitly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

"Means" in the configurations of each of the above devices may be replaced with "unit", "circuit", "device", etc.

As used in this disclosure, any reference to elements using the designations "first," "second," etc. does not generally limit the amount or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Thus, reference to a first and second element does not imply that only two elements may be employed therein or that the first element must precede the second element in any way.

Where "include", "including" and variations thereof are used in this disclosure, these terms, like the term "comprising," are inclusive. It is intended that Furthermore, the term "or" as used in this disclosure is not intended to be exclusive or.

In this disclosure, when articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are plural.

As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of operations. "Judgment" and "decision" include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, search, and inquiry. (e.g., searching in a table, database, or other data structure), and regarding an ascertaining as a "judgment" or "decision." In addition, "judgment" and "decision" refer to receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, and access. (accessing) (e.g., accessing data in memory) may include considering something as a "judgment" or "decision." In addition, "judgment" and "decision" refer to resolving, selecting, choosing, establishing, comparing, etc. as "judgment" and "decision". may be included. In other words, "judgment" and "decision" may include regarding some action as having been "judged" or "determined." Further, "judgment (decision)" may be read as "assuming", "expecting", "considering", etc.

In this disclosure, the term "A and B are different" may mean "A and B are different from each other." Note that the term may also mean that "A and B are each different from C". Terms such as "separate" and "coupled" may also be interpreted similarly to "different."

Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented as modifications and variations without departing from the spirit and scope of the present disclosure as determined by the claims. Therefore, the description of the present disclosure is for the purpose of illustrative explanation and is not intended to have any limiting meaning on the present disclosure.

10 wireless communication systems;
20 terminals
31 E-UTRAN
32NG-RAN
33 Core Network
100 eNB
110 First master station (BBU)
111 Communication Department
113 Control section
120 First slave station (RRH)
200gNB
210 Second master station (O-DU)
211 Communication Department
213 Control section
220 O-RU
300 Intermediate equipment
310 1st Communication Department
320 2nd Communication Department
330 Third Communication Department
340 Control part
1001 processor
1002 memory
1003 Storage
1004 Communication equipment
1005 Input device
1006 Output device
1007 bus

Claims (5)

A communication device,
a first communication unit that performs communication of a first signal in accordance with the first interface with the first master station;
a second communication unit that performs communication of a second signal in accordance with the second interface with a second master station;
a third communication unit that performs communication of a third signal based on the first interface with the first slave station;
a control unit that is connected to the first communication unit, the second communication unit, and the third communication unit, and executes a conversion process between the second signal and the third signal;
The control unit includes:
identifying a subframe number corresponding to the first master station based on subframe number information added to a field included in the first signal received from the first master station;
identifying a subframe number corresponding to the second master station based on information elements included in the second signal received from the second master station;
Based on the subframe number corresponding to the first master station and the subframe number corresponding to the second master station, the first signal received from the first master station and the second signal received from the second master station are determined. A communication device that performs synchronization control to synchronize with two signals. The communication device according to claim 1, wherein the field to which the subframe number is added is a field in which a base station frame number corresponding to the first master station is stored. The control unit includes:
The first signal received from the first master station is transmitted as the third signal to the first slave station, and the second signal received from the second master station is transmitted as the third signal to the first slave station. station, or
transmitting a signal extracted from the third signal received from the first slave station to the first master station as the first signal and transmitting it to the second master station as the second signal; The communication device according to claim 1 or claim 2. The control unit includes:
Extracting a first band signal corresponding to the first master station from the third signal received from the first slave station, and transmitting the extracted signal as the first signal to the first master station. death,
extracting a second band signal corresponding to the second master station from the third signal received from the first slave station, and transmitting the extracted signal to the second master station as the second signal; The communication device according to claim 3. The control unit operates in a first operation mode in which control is executed corresponding to the first master station, a second operation mode in which control is carried out in response to both the first master station and the second master station, and a second operation mode in which control is executed corresponding to the first master station; a third operation mode that executes control corresponding to the
The first operation mode is an operation mode in which the communication device is connected to the first master station, but the communication device is not connected to the second master station,
The second operation mode is an operation mode in which the communication device is connected to the first master station and the second master station,
5. The third operation mode is an operation mode in which the communication device is not connected to the first master station but is connected to the second master station. The communication device according to any one of the items.

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