Communication system, base station device, and control method for communication system

Abstract

To provide a communication system, a base station device, and a control method for the communication system that are capable of performing high-quality communication.SOLUTION: A communication system according to the present disclosure includes a base station device having a plurality of AASs (Active Antenna Systems) and a management device configured to be able to communicate with each of the plurality of AASs. The management device is configured to notify the plurality of AASs of a common time and an ID (Identification) unique to each of the plurality of AASs, and each AAS is configured to perform downlink and uplink calibration within a predetermined period from a predetermined time that is determined by the common time and is periodically set according to the assigned ID.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a communication system, a base station device, and a control method for the communication system. [Background technology]

[0002] The number of AAS stations using sub-6GHz and lower frequency bands, which offer better propagation performance than millimeter waves for 5G mobile applications, is increasing, while the fully digital beamforming method that can achieve high frequency utilization efficiency is being adopted for massive-MIMO spatial multiplexing performance.

[0003] However, even sub-6GHz has inferior propagation performance compared to low band (800MHz platinum band), so in order to expand area coverage while maintaining stable communication performance, it is important to design the base station to eliminate blind spots, similar to LTE, by repeatedly arranging multiple base station devices with a three-sector configuration (configuration using three AASs) that cover 360 degrees horizontally.Technologies related to communication systems are also disclosed in Patent Document 1 and Patent Document 2, for example. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2020-507286 [Patent Document 2] Special Publication No. 2006-515141 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in a base station device having multiple AASs in a communication system disclosed in the related technology, there was a problem in that the accuracy of the calibration of each AAS was degraded due to interference from the DL CAL (Downlink Calibration) signal of each AAS with the UL CAL (Uplink Calibration) signal of other AASs adjacent to that AAS, resulting in a degradation of communication quality.

[0006] An object of the present disclosure is to provide a communication system, a base station device, and a control method for a communication system that solves the above-mentioned problems. [Means for solving the problem]

[0007] The communication system disclosed herein comprises a base station device having a plurality of AASs (Active Antenna Systems), and a management device configured to be able to communicate with each of the plurality of AASs, wherein the management device is configured to notify the plurality of AASs of a common time and an ID (Identification) unique to each of the plurality of AASs, and each of the AASs is configured to perform downlink and uplink calibration within a predetermined period from a predetermined time that is determined by the common time and is periodically set according to the assigned ID.

[0008] The base station device according to the present disclosure has a plurality of AASs (Active Antenna Systems), and each of the AASs is configured to perform downlink and uplink calibration within a predetermined period of time from a predetermined time that is determined by a common time notified to the plurality of AASs and is periodically set according to an assigned unique ID.

[0009] The control method for a communication system according to the present disclosure is a control method for a communication system including a base station device having a plurality of AASs (Active Antenna Systems) and a management device configured to be able to communicate with each of the plurality of AASs, wherein the management device notifies the plurality of AASs of a common time and an ID (Identification) unique to each of the plurality of AASs, and each of the AASs performs downlink and uplink calibration within a predetermined period from a predetermined time that is determined by the common time and is periodically set according to the assigned ID. [Effects of the Invention]

[0010] The present disclosure can provide a communication system, a base station device, and a control method for a communication system that are capable of performing high-quality communication. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic top view of a base station device according to the present disclosure. [Figure 2] FIG. 1 is a schematic perspective view of a base station device according to the present disclosure. [Figure 3] FIG. 1 is a diagram illustrating an example of the arrangement of base station devices according to the present disclosure. [Figure 4] FIG. 1 is a diagram for explaining the problem of a base station device configured with multiple AASs. [Figure 5] FIG. 1 is a diagram for explaining the problem of a base station device configured with multiple AASs. [Figure 6] FIG. 1 is a diagram illustrating an example configuration of a communication system according to the present disclosure. [Figure 7] 10 is a timing chart showing the operation of a base station device according to the present disclosure. [Figure 8] 10 is a timing chart showing in more detail a portion of the operation of a base station device according to the present disclosure. [Figure 9] 10 is a timing chart showing in more detail a portion of the operation of a base station device according to the present disclosure. [Figure 10] 10 is a timing chart showing in more detail a portion of the operation of a base station device according to the present disclosure. [Figure 11] 1 is a block diagram illustrating an example of a hardware configuration for implementing part or all of the communication control functions of a communication system according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments will be described with reference to the drawings. Note that the drawings are simplified, and the technical scope of the embodiments should not be narrowly interpreted based on the description in the drawings. Furthermore, identical elements are given the same reference numerals, and duplicate explanations will be omitted.

[0013] In the following embodiments, when necessary for convenience, the description will be divided into multiple sections or embodiments. However, unless otherwise specified, they are not unrelated to each other, and one is a partial or complete modification, application example, detailed explanation, supplementary explanation, etc. of the other. Furthermore, in the following embodiments, when the number of elements (including the number, numerical value, amount, range, etc.) is mentioned, it is not limited to that specific number, and may be more or less than the specific number, unless otherwise specified or when it is clearly limited to a specific number in principle.

[0014] Furthermore, in the following embodiments, the components (including operational steps, etc.) are not necessarily essential unless otherwise specified or considered to be clearly essential in principle. Similarly, in the following embodiments, when referring to the shape, positional relationship, etc. of components, etc., it is intended to include those that are substantially similar or approximate to the shape, etc., unless otherwise specified or considered to be clearly not essential in principle. The same applies to the above numbers, etc. (including numbers, numerical values, amounts, ranges, etc.).

[0015] <First Embodiment> Fig. 1 is a schematic top view of a base station device 1 according to the present disclosure, and Fig. 2 is a schematic perspective view of the base station device 1 according to the present disclosure.

[0016] The base station device 1 has a spatial multiplexing function using Massive-MIMO (MU-MIMO) and is configured to be able to perform communications using digital beamforming. Specifically, the base station device 1 includes three flat AASs 11-13 arranged around a pole P1. That is, the base station device 1 employs a three-sector configuration in which the three AASs 11-13 each cover 120 degrees (Azimuth angle ±60 degrees) in a horizontal 360-degree direction.

[0017] Each of the AASs 11-13 includes a plurality of antenna elements arranged in a matrix and a plurality of transceivers corresponding to the antenna elements. For example, in each of the AASs 11-13, two sets of antenna groups, each consisting of two antenna elements arranged along the vertical direction (z-axis direction), are arranged along the vertical direction, and eight sets are arranged along the horizontal direction (direction on the x-y plane). Furthermore, two tiers of flat antenna arrays, each consisting of 2 x 8 sets of antenna groups (i.e., 4 x 8 antenna elements), are stacked. Of the two tiers of antenna arrays, the front (outer) antenna array is a -45-degree polarized antenna, and the rear (inner) antenna array is a +45-degree polarized antenna, forming a ±45-degree orthogonal polarized dual-use antenna. Furthermore, a transceiver is provided for each antenna group. In other words, each of the AASs 11-13 includes 32 sets of antenna groups (64 antenna elements) and 32 transceivers.

[0018] Fig. 3 is a diagram showing an example of the placement of base station devices 1. As shown in Fig. 3, multiple base station devices 1 with a three-sector configuration covering 360 degrees horizontally are placed repeatedly in a planar manner. This enables a station placement design that eliminates blind spots.

[0019] Here, each of the AASs 11 to 13 is configured to periodically perform DL CAL and UL CAL. DL CAL is an abbreviation for Downlink Calibration. UL CAL is an abbreviation for Uplink Calibration. DL CAL and UL CAL are collectively referred to as DL / UL CAL. By performing DL / UL CAL, each of the AASs 11 to 13 performs processing to match the amplitude-phase-frequency characteristics of all transceivers (TRX) installed within the AAS.

[0020] However, in a typical three-sector base station device, the DL CAL signal radiated and leaked from the antenna of each AAS to the outside causes interference with the UL CAL signal of the antenna of the AAS adjacent to the AAS (causing the CAL signal to leak and re-coupling to the adjacent AAS antenna), which degrades the accuracy of the UL CAL of each AAS and results in a degradation of communication quality. Note that the DL / UL CAL signal is a signal transmitted and received within each AAS during a Transmit On / Off Period (e.g., 10 usec) around the time slot before and after the DL slot.

[0021] 4 and 5 are diagrams for explaining the problems of a general base station device 50 configured with three AASs 51 to 53. In the example of Fig. 5, only two AASs 51 and 52 are shown as representatives of the three AASs 51 to 53. The AASs 51 to 53 correspond to the AASs 11 to 13, respectively, and have the same basic structure as the AASs 11 to 13.

[0022] 4 and 5, adjacent AASs 51 and 52 experience interference from each other's DL CAL signals to their own UL CAL signals. Similarly, adjacent AASs 52 and 53 experience interference from each other's DL CAL signals to their own UL CAL signals. Similarly, adjacent AASs 53 and 51 experience interference from each other's DL CAL signals to their own UL CAL signals.

[0023] For example, in the base station device 50, after each AAS 51 to 53 is started, a CU (Central Unit) or DU (Distributed Unit), which is a higher-level device than an RU (Radio Unit; i.e., AAS), synchronizes the DL / UL TDD timing from the DU to each AAS 51 to 53 based on a 1PPS (Pulse Per Second) signal received from a GPS (GNSS) satellite by the CU or DU, and a reference clock signal of about 10 MHz generated based on the 1PPS signal. Note that GPS is an abbreviation for Global Positioning System. GNSS is an abbreviation for Global Navigation Satellite System. The synchronization at this time is, for example, synchronization based on PTP (Precision Time Protocol). Here, DL / UL CAL is performed in each AAS 51 to 53 within a Transmit On / Off Period (e.g., 10 usec) in a time slot before or after a DL slot after TRX setting is completed. However, in each of the AASs 51 to 53, the CAL cycle is started by a startup instruction from the middleware to the RF software, so the DL / UL CAL sequence of the DL / UL CAL is performed cyclically asynchronously. Therefore, in the base station device 50, the asynchronous DL CAL signal radiated and leaked to the outside from the antenna of each of the AASs 51 to 53 interferes with the UL CAL signal of the antenna of the AAS adjacent to that AAS, degrading the accuracy of the UL CAL of each of the AASs 51 to 53 and resulting in degradation of communication quality.

[0024] Therefore, in the base station device 1 according to the present disclosure, each of the AASs 11 to 13 is configured to perform DL / UL CAL within a predetermined period from a predetermined time that is periodically set according to the assigned unique ID. The unique ID is, for example, the number of the sector under the jurisdiction of the AASs 11 to 13, and is notified to each of the AASs 11 to 13 from the DU via the optical fronthaul. As a result, each of the AASs 11 to 13 recognizes the unique ID, such as the sector number. Furthermore, the predetermined time set in each of the AASs 11 to 13 is defined by a common time, such as absolute time, notified to each of the AASs 11 to 13 from the DU. The common time, such as absolute time, is PTP synchronized based on a 1PPS signal received by an upper device, such as an RU, from a GPS (GNSS) and a reference clock signal generated based on the signal.

[0025] For example, AAS11 performs DL / UL CAL within a predetermined period Taas1 from time t11, which is set according to an assigned unique ID (e.g., sector number 1). AAS12 performs DL / UL CAL within a predetermined period Taas2 from time t12, which is set according to an assigned unique ID (e.g., sector number 2). AAS13 performs DL / UL CAL within a predetermined period Taas3 from time t13, which is set according to an assigned unique ID (e.g., sector number 3). Here, times t11, t12, and t13 are PTP synchronized based on a 1PPS signal received from GPS (GNSS) and a reference clock signal generated based on that signal, and are specified by a common time such as absolute time notified to AAS11 to AAS13 via DU. AAS11 to AAS13 set the predetermined time t11 and predetermined period Taas1, the predetermined time t12 and predetermined period Taas2, and the predetermined time t13 and predetermined period Taas3, respectively, so that the time period from time t11 to the predetermined period Taas1, the time period from time t12 to the predetermined period Taas2, and the time period from time t13 to the predetermined period Taas3 do not overlap.

[0026] As a result, the base station device 1 according to the present disclosure can perform DL / UL CAL for each of the AASs 11 to 13 with high accuracy without interference from adjacent AASs, thereby enabling high-quality communication.

[0027] Fig. 6 is a diagram showing an example of the configuration of a communication system SYS1 to which a base station device 1 is applied. As shown in Fig. 6, the communication system SYS1 includes a CU3, n DUs 2, and n base station devices 1, where n is a positive integer. The n DUs 2 are also referred to as DUs 2_1 to 2_n, and the n base station devices 1 are also referred to as base station devices 1_1 to 1_n. The DUs 2 also serve as management devices for the base station devices 1.

[0028] For example, CU3 receives a 1PPS signal from a GPS (GNSS) not shown. Based on this 1PPS signal and a reference clock signal generated based on it, DL / UL TDD timing from DU2_1 to each AAS 11-13 of base station device 1_1 is synchronized. Similarly, synchronization from DU2_2-2_n to base station devices 1_2-1_n is also performed. The configuration and operation of each of base station devices 1_1-1_n are similar to those of base station device 1. Base station devices 1_1-1_n are arranged, for example, in an arrangement example as shown in FIG. 3. This enables station placement design that eliminates blind zones.

[0029] Fig. 7 is a timing chart showing the operation of the base station device 1. Figs. 8 to 10 are timing charts showing in more detail the operation of the base station device 1. In the example of Figs. 7 to 10, DL / UL CAL of the AASs 11 to 13 is performed periodically, with one cycle being one minute (=10 msec / Frame × 6000 Frames).

[0030] 8 to 10, one 10 msec frame is made up of 10 subframes, and one 1 msec subframe is made up of two slots. One 0.5 msec slot is made up of 14 symbols. Each slot is either a DL, UL, or flexible slot. In the examples of FIGS. 8 to 10, "D" represents a DL slot, "U" represents a UL slot, and "F" represents a flexible slot. Furthermore, in the examples of FIGS. 8 to 10, the TDD DL / UL configuration is based on the Japanese and German DDDFU conditions, and DL / UL CAL is performed in the TX Off transient (10 usec) immediately after the DL slot tail in the "F" slot of each DDDFU.

[0031] As already explained, in the base station device 1 according to the present disclosure, each of the AASs 11 to 13 is configured to perform DL CAL and UL CAL within a predetermined period from a predetermined time that is periodically set according to an assigned unique ID. The unique ID is, for example, the number of the sector under the jurisdiction of the AASs 11 to 13, and is notified to each of the AASs 11 to 13 from the DU via the optical fronthaul. The predetermined time set in each of the AASs 11 to 13 is defined by a common time such as absolute time that is notified to each of the AASs 11 to 13 from the DU. The common time such as absolute time is PTP synchronized based on a 1PPS signal received by an upper device such as an RU from a GPS (GNSS) and a reference clock signal generated based on the signal.

[0032] Specifically, first, the AAS 11 performs DL / UL CAL in response to a start instruction from the middleware to the RF software within a predetermined period Taas1 from time t11, which is the absolute time set according to sector number 1 assigned by the DU. DL CAL is performed sequentially by 32 transmitters corresponding to 32 antenna groups (64 antenna elements) installed in the AAS 11. UL CAL is performed collectively by 32 receivers after DL CAL.

[0033] Thereafter, the AAS 12 performs DL / UL CAL in response to a start instruction from the middleware to the RF software within a predetermined period Taas2 from time t12, which is the absolute time set according to sector number 2 assigned by the DU. DL CAL is performed sequentially by 32 transmitters corresponding to 32 antenna groups (64 antenna elements) installed in the AAS 12. UL CAL is performed collectively by 32 receivers after DL CAL. Here, time t12, at which the AAS 12 performs DL / UL CAL, is set to be later than the time after the predetermined period Taas1 has elapsed from time t11. This prevents the DL / UL CALs of the AASs 11 and 12 from overlapping, preventing interference between the DL / UL CAL signals of the AASs 11 and 12.

[0034] Thereafter, AAS 13 performs DL / UL CAL in response to a startup instruction from the middleware to the RF software within a predetermined period Taas3 from time t13, which is an absolute time set according to sector number 3 assigned by the DU. DL CAL is performed sequentially by 32 transmitters corresponding to 32 antenna groups (64 antenna elements) installed in AAS 13. UL CAL is performed collectively by 32 receivers after DL CAL. Here, time t13, at which AAS 13 performs DL / UL CAL, is set to be later than the time after the predetermined period Taas2 has elapsed from time t12. This prevents the DL / UL CALs of AAS 12 and 13 from overlapping, thereby preventing interference between the DL / UL CAL signals of AAS 12 and 13.

[0035] Furthermore, the time after the lapse of a predetermined period Taas3 from time t13 is set to be earlier than the time at which the one-minute cycle in which DL / UL CAL is performed once each for AAS11 to 13 has elapsed. Therefore, even if DL / UL CAL is performed again by AAS11 in the next cycle, the DL / UL CALs of AAS13 and AAS11 will not overlap, and therefore interference of the DL / UL CAL signals between AAS13 and AAS11 will not occur.

[0036] In this way, in the base station device 1 according to the present disclosure, each AAS 11-13 performs DL / UL CAL according to a time determined by a common time and corresponding to a unique ID, so as not to overlap with DL / UL CAL of other adjacent AASs. This allows the base station device 1 according to the present disclosure to suppress interference with the UL CAL signal of the antenna of an AAS adjacent to the AAS, caused by the DL CAL signal radiated and leaking from the antenna of each AAS 11-13. For example, this eliminates delay errors in UL CAL, normalizes the UL CAL time signal, and normalizes the frequency spectrum of the UL CAL signal. This allows the base station device 1 according to the present disclosure to prevent degradation of the accuracy of DL / UL CAL of each AAS 11-13, thereby achieving high-quality communications.

[0037] In the present disclosure, the base station device 1 has been described as having three AASs 11 to 13, but the present invention is not limited to this and can be appropriately modified to have two or more AASs.

[0038] The times t11, t12, and t13 and the predetermined periods Taas1, Taas2, and Taas3 may be set in minutes or seconds, or may be defined by the period of each Round Sequence. Furthermore, the times t11, t12, and t13 and the predetermined periods Taas1, Taas2, and Taas3 are not limited to being defined by absolute time, but may also be defined by the period of the number of frames, the frequency of the CAL itself, or the like. For example, the start time of DL / UL CAL for AAS11 may be defined by the frame number. Alternatively, exclusive processing may be applied, such as not performing CAL processing in sectors other than the sector in CAL operation.

[0039] Furthermore, it is expected that specifications regarding notification of sector numbers from the DU to each of the AASs 11 to 13 of the base station device 1 will also be introduced into the ORAN (Open Radio Access Network) standard. In that case, it is considered possible to present sector numbers to the AASs of each sector configuration via ORAN C-Plane control. Note that even in a system configuration in which the DU and RU are not ORAN-compliant and multi-vendor, if the DU and RU are from the same vendor or are an integrated device, it is considered possible to apply the base station device 1 of the present disclosure even if they do not comply with the ORAN specifications.

[0040] The present disclosure has significant features in that it can increase the number of layers for simultaneous multi-terminal connections, i.e., the Throughput, through Massive MIMO when configured in a three-sector configuration with an AAS integrated with a massive-element antenna that enables Massive MIMO, and can avoid CAL performance degradation due to CAL signal interference and recombination between adjacent (or nearby) AASs during DL / UL CAL, which is essential for AAS to maximize frequency utilization efficiency. It also has a significant effect in that it can stably maximize cell Throughput in a three-sector configuration.

[0041] Furthermore, for Massive MIMO AAS, miniaturization and weight reduction are important to further expand the currently insufficient 5G area coverage rate and improve the stability of communication quality regardless of location, while achieving high speed and capacity with high frequency utilization efficiency in the sub-6GHz band. Furthermore, in response to the shortage of station locations, particularly in urban areas where 5G traffic demand is increasing, it is expected that operation of station locations will be outsourced and transferred to tower companies, resulting in high-density placement of AASs for many different operators in the same station location, and increased demand for RAN sharing by sharing AASs. In such cases, the effectiveness of this disclosure in avoiding degradation of spatial multiplexing performance due to DL / UL CAL interference between adjacent (or nearby) AASs is expected to be significant.

[0042] Furthermore, as the shift to 5G Stand Alone accelerates, replacing LTE / 4G, towards B5G / 6G from 2030 onwards, this disclosure will be highly effective because it will be necessary to avoid DL / UL CAL interference between adjacent AASs in order to achieve area coverage and stable communication quality with the high-density AAS deployment disclosed in this disclosure.

[0043] (Hardware configuration for realizing the communication control function of communication system SYS1) A part or all of the communication control processing performed by the communication system SYS1 can be realized by a general-purpose computer system. In other words, the communication control processing performed by the management device (DU) 2 and the base station device 1 in the communication system SYS1 can be realized by a general-purpose computer system. A brief explanation will be given below with reference to FIG. 11.

[0044] 11 is a block diagram showing an example of a hardware configuration that realizes some or all of the communication control functions of the communication system SYS1. The computer 300 includes, for example, a CPU (Central Processing Unit) 301, which is a control device, a RAM (Random Access Memory) 302, and a ROM (Read Only Memory) 303. The computer 300 further includes an IF (Interface) 304, which is an interface with the outside, and an HDD (Hard Disk Drive) 305, which is an example of a non-volatile storage device. The computer 300 may also include input devices such as a keyboard and a mouse, and a display device such as a display, as other components not shown.

[0045] The HDD 305 stores an OS (Operating System) (not shown) and a control program 306. The control program 306 is a computer program that implements communication control processing for the communication system SYS1.

[0046] The CPU 301 controls various processes in the computer 300, access to the RAM 302, the ROM 303, the IF 304, and the HDD 305, etc. In the computer 300, the CPU 301 reads and executes the OS and the control program 306 stored in the HDD 305. In this way, the computer 300 realizes the communication control function of the communication system SYS1.

[0047] The above-mentioned program includes instructions (or software code) that, when loaded into a computer, cause the computer to perform one or more functions described in this disclosure. The program may be stored on a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, computer-readable medium or tangible storage medium includes RAM, ROM, flash memory, solid-state drive (SSD) or other memory technology, CD-ROM, digital versatile disc (DVD), Blu-ray disc or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may also be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, transitory computer-readable medium or communication medium includes electrical, optical, acoustic, or other forms of propagated signals.

[0048] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0049] Each drawing is merely an example for describing one or more embodiments. Each drawing may relate not only to one particular embodiment, but also to one or more other embodiments. As will be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings to create, for example, an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessary to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

[0050] Furthermore, some or all of the above-described embodiments can be described as, but are not limited to, the following supplementary notes.

[0051] (Appendix 1) a base station device having a plurality of AASs (Active Antenna Systems); a management device configured to be able to communicate with each of the plurality of AASs; Equipped with the management device is configured to notify the plurality of AASs of a common time and an ID (Identification) unique to each of the plurality of AASs; Each AAS is configured to perform downlink and uplink calibration within a predetermined period from a predetermined time defined by the common time and periodically set according to the assigned ID. Communication system.

[0052] (Appendix 2) Each AAS sets the predetermined time and the predetermined period so that the time period for performing downlink and uplink calibration does not overlap with the time period for calibration by another AAS. 10. The communication system of claim 1.

[0053] (Appendix 3) The base station device has three AASs as the plurality of AASs. 10. The communication system of claim 1.

[0054] (Appendix 4) Further provided is an optical fronthaul used for communication between each of the plurality of AASs and the management device, 10. The communication system of claim 1.

[0055] (Appendix 5) It has multiple AAS (Active Antenna Systems), Each of the AASs is configured to perform downlink and uplink calibration within a predetermined period from a predetermined time that is defined by a common time notified to the plurality of AASs and is periodically set according to an assigned unique ID. Base station equipment.

[0056] (Appendix 6) Each AAS sets the predetermined time and the predetermined period so that the time period for performing downlink and uplink calibration does not overlap with the time period for calibration by another AAS. 6. A base station apparatus according to claim 5.

[0057] (Appendix 7) The plurality of AASs includes three AASs. 6. A base station apparatus according to claim 5.

[0058] (Appendix 8) a base station device having a plurality of AASs (Active Antenna Systems); a management device configured to be able to communicate with each of the plurality of AASs; A control method for a communication system, comprising: The management device notifies the plurality of AASs of a common time and an ID (Identification) unique to each of the plurality of AASs; In each of the AASs, downlink and uplink calibration is performed within a predetermined period from a predetermined time that is defined by the common time and is periodically set according to the assigned ID. A method for controlling a communication system.

[0059] (Appendix 9) In each AAS, the predetermined time and the predetermined period are set so that the time period for performing downlink and uplink calibration does not overlap with the time period for calibration by another AAS. 9. A method for controlling a communication system according to claim 8.

[0060] (Appendix 10) The base station device has three AASs as the plurality of AASs. 9. A method for controlling a communication system according to claim 8.

[0061] (Appendix 11) A control method for a base station device having a plurality of AASs (Active Antenna Systems), In each of the AASs, downlink and uplink calibration is performed within a predetermined period from a predetermined time that is defined by a common time notified to the plurality of AASs and is periodically set according to an assigned unique ID. A method for controlling a base station device.

[0062] (Appendix 12) A control program that causes a computer to execute control processing in a base station device having a plurality of AASs (Active Antenna Systems), In each of the AASs, a process of performing downlink and uplink calibration within a predetermined period from a predetermined time that is defined by a common time notified to the plurality of AASs and is periodically set according to an assigned unique ID, A control program executed by a computer.

[0063] Some or all of the elements (e.g., configurations and functions) described in Supplementary Notes 2 to 4 that are dependent on Supplementary Note 1 may also be dependent on Supplementary Notes 11 and 12 in the same dependency relationship as Supplementary Notes 2 to 4. Some or all of the elements described in any Supplementary Note may be applied to various hardware, software, recording means for recording software, systems, and methods. [Explanation of symbols]

[0064] 1 Base station equipment 2 DU 2_1~2_n DU 3 CU 11 AAS 12 AAS 13 AAS 300 Computers 301 CPU 302 RAM 303 ROM 304 IF 305 HDD 306 Control Program P1 Pole SYS1 Communication System

Claims

1. A base station device having a plurality of AASs (Active Antenna Systems); a management device configured to be able to communicate with each of the plurality of AASs; Equipped with the management device is configured to notify the plurality of AASs of a common time and an ID (Identification) unique to each of the plurality of AASs; Each of the AASs is configured to perform downlink and uplink calibration within a predetermined period from a predetermined time that is defined by the common time and is periodically set according to the assigned ID. Communication system.

2. Each AAS sets the predetermined time and the predetermined period so that the time period for performing downlink and uplink calibration does not overlap with the time period for calibration by another AAS. The communication system of claim 1 .

3. The base station device has three AASs as the plurality of AASs. The communication system of claim 1 .

4. An optical fronthaul is further provided between each of the plurality of AASs and the management device for communication. The communication system of claim 1 .

5. It has multiple AASs (Active Antenna Systems), Each of the AASs is configured to perform downlink and uplink calibration within a predetermined period from a predetermined time that is defined by a common time notified to the plurality of AASs and is periodically set according to an assigned unique ID. Base station equipment.

6. Each AAS sets the predetermined time and the predetermined period so that the time period for performing downlink and uplink calibration does not overlap with the time period for calibration by another AAS. The base station device according to claim 5 .

7. The plurality of AASs includes three AASs. The base station device according to claim 5 .

8. A base station device having a plurality of AASs (Active Antenna Systems); a management device configured to be able to communicate with each of the plurality of AASs; A control method for a communication system, comprising: The management device notifies the plurality of AASs of a common time and an ID (Identification) unique to each of the plurality of AASs; In each of the AASs, downlink and uplink calibration is performed within a predetermined period from a predetermined time that is defined by the common time and is periodically set according to the assigned ID. A method for controlling a communication system.

9. In each AAS, the predetermined time and the predetermined period are set so that the time period for performing downlink and uplink calibration does not overlap with the time period for calibration by another AAS. The method for controlling a communication system according to claim 8.

10. The base station device has three AASs as the plurality of AASs. The method for controlling a communication system according to claim 8.

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