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WO2017119077A1 - Appareil de communications, appareil de station de base, système de communications mobiles, procédé de communications, et appareil de station mobile - Google Patents

Appareil de communications, appareil de station de base, système de communications mobiles, procédé de communications, et appareil de station mobile Download PDF

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Publication number
WO2017119077A1
WO2017119077A1 PCT/JP2016/050222 JP2016050222W WO2017119077A1 WO 2017119077 A1 WO2017119077 A1 WO 2017119077A1 JP 2016050222 W JP2016050222 W JP 2016050222W WO 2017119077 A1 WO2017119077 A1 WO 2017119077A1
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WO
WIPO (PCT)
Prior art keywords
base station
cell
configuration
mobile station
location information
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2016/050222
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English (en)
Japanese (ja)
Inventor
小川浩二
田中隼輔
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujitsu Ltd
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Fujitsu Ltd
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Filing date
Publication date
Application filed by Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to PCT/JP2016/050222 priority Critical patent/WO2017119077A1/fr
Publication of WO2017119077A1 publication Critical patent/WO2017119077A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/02—Resource partitioning among network components, e.g. reuse partitioning
    • H04W16/06—Hybrid resource partitioning, e.g. channel borrowing
    • H04W16/08—Load shedding arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/24—Cell structures
    • H04W16/28—Cell structures using beam steering
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/16—Performing reselection for specific purposes
    • H04W36/22—Performing reselection for specific purposes for handling the traffic
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/24—Reselection being triggered by specific parameters
    • H04W36/32—Reselection being triggered by specific parameters by location or mobility data, e.g. speed data
    • H04W36/322—Reselection being triggered by specific parameters by location or mobility data, e.g. speed data by location data
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Definitions

  • the present invention relates to a communication device, a base station device, a mobile communication system, a communication method, and a mobile station device.
  • LTE Long Term Evolution
  • LTE-Advanced successor systems Such a system is called fifth generation mobile communication (5G: the: 5th Generation mobile communication).
  • 5G the: 5th Generation mobile communication
  • CA Carrier Aggregation
  • AAS Active Antenna Array System
  • AAS is, for example, a base station system in which an antenna array and an active transmission unit array are integrated.
  • a radio signal transmission / reception function is integrated with an antenna and installed in a base station device, so that a high-quality service area can be realized, and the base station device can be downsized and power efficiency can be improved. Is possible.
  • one sector can be divided into a plurality of cells by cell forming in the vertical direction (Cell ⁇ ⁇ ⁇ ⁇ splitting), or a plurality of carriers can be individually controlled (Carrier-specific tilting) by tilt control. Become.
  • handover for radio communication.
  • handover completion waiting timer T RELOCprep and TX2 RELOC Coverall in LTE
  • T304 in LTE a handover completion waiting timer notified to the mobile station
  • the load may increase at the base station as compared to before the handover.
  • the mobile station may be handed over to the base station before starting operation. In this case, the mobile station may not be able to complete handover to the base station within the valid period of the handover completion waiting timer.
  • one disclosure is to provide a base station apparatus, a communication apparatus, a mobile communication system, a communication method, and a mobile station apparatus that appropriately control the cell capacity.
  • one disclosure is to provide a base station device, a communication device, a mobile communication system, a communication method, and a mobile station device that ensure continuity of communication.
  • a communication device connectable with a location information server that manages location information of a mobile station device
  • traffic information relating to traffic between a base station device and the mobile station device is received from the base station device
  • a transmitting / receiving unit that receives the location information of the mobile station device from the location information server, and a configuration of an antenna in the base station device is changed from a first configuration to a second configuration based on the traffic information and the location information
  • a determination unit that transmits an instruction to change to the second configuration to the base station device via the transmission / reception unit.
  • a base station apparatus it is possible to provide a base station apparatus, a communication apparatus, a mobile communication system, a communication method, and a mobile station apparatus that appropriately control the cell capacity. Further, according to one disclosure, it is possible to provide a base station apparatus, a communication apparatus, a mobile communication system, a communication method, and a mobile station apparatus that ensure communication continuity.
  • FIG. 1 is a diagram illustrating a configuration example of a mobile communication system.
  • FIG. 2 is a diagram illustrating a configuration example of a mobile communication system.
  • FIG. 3A shows an example of cell division
  • FIG. 3B shows an example of cell integration.
  • FIG. 4 is a diagram illustrating a configuration example of the base station apparatus.
  • FIG. 5 is a diagram illustrating a configuration example of a mobile station apparatus.
  • FIG. 6 is a diagram illustrating a configuration example of the maintenance system.
  • FIG. 7 is a diagram illustrating a configuration example of an access gateway.
  • FIG. 8 is a diagram illustrating an example of a cell division processing flow.
  • FIG. 9 is a diagram illustrating an example of a cell division processing flow.
  • FIG. 1 is a diagram illustrating a configuration example of a mobile communication system.
  • FIG. 2 is a diagram illustrating a configuration example of a mobile communication system.
  • FIG. 3A shows an example of cell division
  • FIG. 3B
  • FIG. 10 is a diagram illustrating an example of a cell division processing flow.
  • FIG. 11 is a diagram illustrating an example of a cell integration processing flow.
  • FIG. 12 is a diagram illustrating an example of a cell integration processing flow.
  • FIG. 13 is a diagram illustrating an example of a cell integration processing flow.
  • FIG. 14 is a diagram illustrating an example of a handover sequence by cell division.
  • FIG. 15 is a diagram illustrating an example of a handover sequence by cell division.
  • FIG. 16 is a diagram illustrating an example of a sequence at the time of handover failure.
  • FIG. 17 is a diagram illustrating an example of a handover sequence by cell division.
  • FIG. 18 is a diagram illustrating an example of a handover sequence by cell division.
  • FIG. 11 is a diagram illustrating an example of a cell integration processing flow.
  • FIG. 12 is a diagram illustrating an example of a cell integration processing flow.
  • FIG. 13 is a diagram illustrating an example
  • FIG. 19 is a diagram illustrating an example of a sequence at the time of handover failure.
  • FIG. 20 is a diagram illustrating an example of a handover sequence from another station.
  • FIG. 21 is a diagram illustrating an example of a handover sequence from another station.
  • FIG. 22 is a diagram illustrating an example of a handover sequence by cell integration.
  • FIG. 23 is a diagram illustrating an example of a handover sequence by cell integration.
  • FIG. 24 is a diagram illustrating an example of a handover sequence from another station.
  • FIG. 25 is a diagram illustrating an example of a handover sequence from another station.
  • FIG. 26 is a diagram illustrating a configuration example of a mobile communication system.
  • FIG. 27 is a diagram illustrating an example of a cell division / integration determination sequence.
  • FIG. 28 is a diagram illustrating an example of a cell division / integration determination sequence.
  • FIG. 29 is a diagram illustrating a configuration example of a mobile communication system.
  • FIG. 30 is a diagram illustrating an example of a cell division / integration determination sequence.
  • FIG. 31 is a diagram illustrating an example of cell division.
  • FIG. 32 is a diagram illustrating an example of a cell division processing sequence.
  • FIG. 33 is a diagram illustrating an example of cell integration.
  • FIG. 34 is a diagram illustrating an example of a cell integration processing sequence.
  • FIG. 35 is a diagram illustrating an example of handover from a neighboring eNB.
  • FIG. 36 is a diagram illustrating an example of a handover sequence from a neighboring eNB.
  • FIG. 35 is a diagram illustrating an example of handover from a neighboring eNB.
  • FIG. 37 is a diagram illustrating an example of a handover sequence from a neighboring eNB.
  • FIG. 38 is a diagram illustrating an example of a rollback sequence.
  • FIG. 39 is a diagram illustrating a hardware configuration of the base station apparatus.
  • FIG. 40 is a diagram illustrating a hardware configuration example of the mobile station apparatus.
  • FIG. 41 is a diagram illustrating a hardware configuration example of a maintenance system, an access gateway, or a location information server.
  • FIG. 1 is a diagram illustrating a configuration example of a mobile communication system 10 according to the first embodiment.
  • the mobile communication system 10 includes a base station device 100, a mobile station device 200, a location information server 500, and a communication device 600.
  • the base station device 100 performs wireless communication with the mobile station device 200.
  • the location information server 500 manages traffic information related to traffic between the base station device 100 and the mobile station device 200.
  • the communication device 600 can be connected to the position information server 500.
  • the communication device 600 includes a transmission / reception unit 610 and a determination unit 620.
  • the transmission / reception unit 610 receives traffic information regarding traffic between the base station apparatus 100 and the mobile station apparatus 200 from the base station apparatus 100. Further, the transmission / reception unit 610 receives the position information of the mobile station device 200 from the position information server 500.
  • the determination unit 620 determines to change the antenna configuration in the base station apparatus 100 from the first configuration to the second configuration based on the traffic information and the position information, and moves to the second configuration via the transmission / reception unit 610. Is transmitted to the base station apparatus 100.
  • the communication apparatus 600 can analyze, for example, the bias of the mobile station apparatus 200 connected to the base station apparatus 100 based on the traffic information and the position information. .
  • Communication apparatus 600 can determine the antenna configuration in base station apparatus 100 that can achieve optimal cell division or cell integration against such a bias.
  • the number of cells under the base station apparatus 100 is increased by dividing the cells under the base station apparatus 100 based on traffic information and location information, and the number of controllable (or accommodable) mobile station apparatuses 200 is increased. Also increases. Thereby, for example, the cell capacity of the base station apparatus 100 is appropriately expanded, and it becomes possible to cope with the congestion state in the base station apparatus 100.
  • cell integration under the base station apparatus 100 can be determined based on traffic information and position information.
  • the number of cells under the base station apparatus 100 decreases, it is possible to suppress inter-cell interference and frequent handovers due to the increase in the number of cells.
  • the cell capacity of the base station apparatus 100 can be appropriately reduced.
  • the mobile communication system 10 in the first embodiment can appropriately control the capacity of cells under the base station apparatus 100.
  • the base station apparatus 100 may determine to change the antenna configuration.
  • the base station apparatus 100 includes a traffic information management unit 170, a transmission / reception unit 171, and a control unit 172.
  • the traffic information management unit 170 acquires traffic information related to traffic between the mobile station device 200 and the base station device 100.
  • the transmission / reception unit 171 receives the location information of the mobile station device 200 managed by the location information server 500 from the location information server 500 via the communication device 600.
  • the control unit 172 changes the antenna configuration from the first configuration to the second configuration based on the traffic information and the position information.
  • the base station apparatus 100 can determine cell division or integration by changing the antenna configuration based on traffic information and location information, and can appropriately increase or decrease the number of cells. It is also possible to control the cell capacity appropriately.
  • base station apparatus 100 transmits a handover start instruction including three new parameters to mobile station apparatus 200.
  • the three new parameters are, for example, “Cell Deployment Indicator”, “Wait Time”, and “Sync Mode”.
  • Cell Deployment Indicator indicates, for example, that the cell is divided or integrated.
  • Wiit Time indicates, for example, the processing time (or maximum processing time) from the start to the end of cell division processing or cell integration processing in the base station apparatus 100.
  • Sync Mode indicates, for example, whether the synchronization processing is performed by the base station device or the mobile station.
  • the mobile station apparatus 200 can invalidate the time set as a handover completion waiting timer (eg, T304) and perform the handover process using the timer indicated by “Wait Time”. It becomes possible. As a result, for example, the mobile station apparatus 200 can avoid a situation in which the handover to the divided cell cannot be performed due to the expiration of the handover completion waiting timer, and the time required for connection to the base station apparatus 100 is guaranteed. . Therefore, the mobile station apparatus 200 is guaranteed to be handed over to the cell after cell division or cell integration, and the mobile communication system 10 can ensure continuity of communication.
  • T304 a handover completion waiting timer
  • a cell is, for example, a network object that can be uniquely identified by (cell) identification information by a mobile station apparatus (hereinafter also referred to as “mobile station”).
  • the cell may be, for example, a service area formed by one base station apparatus (hereinafter sometimes referred to as “base station”), or a combination of the service area and the base station. Also good.
  • base station a base station apparatus
  • a cell and a base station may be used interchangeably without being distinguished.
  • AAS is, for example, a base station system in which an antenna array and an active transmission unit array are integrated.
  • AAS is a system in which a radio signal transmission / reception function is integrated with an antenna and mounted in a base station apparatus, for example.
  • AAS is described in Non-Patent Document 1 described above.
  • the antenna reconfiguration is, for example, changing the antenna configuration at the base station from the first configuration to the second configuration.
  • an example of antenna reconfiguration is AAS, and any method other than AAS may be used as long as the configuration of the antenna is changed.
  • AAS any method other than AAS may be used as long as the configuration of the antenna is changed.
  • a base station using AAS may be described, but the second embodiment can be implemented even for a base station that changes the antenna configuration by a method other than AAS. .
  • Non-Patent Document 4 six patterns are described as AAS. For example, there are cell splitting that divides cells by beam forming in the vertical direction, carrier-specific tilting that divides carriers (or frequencies) by controlling the tilt angle, and the like. Antenna reconfiguration enables cell division and integration, carrier division and integration, and the like.
  • the antenna reconfiguration patterns may include the six patterns described in Non-Patent Document 4 described above.
  • FIG. 2 is a diagram illustrating a configuration example of the mobile communication system 10.
  • the mobile communication system 10 includes base station devices (hereinafter also referred to as “base stations”) 100-1 and 100-2, mobile station devices (hereinafter also referred to as “mobile stations”) 200-1, 200-2.
  • base stations base station devices
  • mobile station devices hereinafter also referred to as “mobile stations”
  • the mobile communication system 10 includes an EMS / NMS (Element Management System / Network Management System) 300 (hereinafter also referred to as “maintenance system”), an access gateway 400, and a location information server 500.
  • EMS / NMS Event Management System / Network Management System 300
  • access gateway 400 access gateway
  • location information server 500 location information server
  • the communication device 600 in the first embodiment corresponds to the maintenance system 300 or the access gateway 400, for example.
  • the base stations 100-1 and 100-2 are wireless communication devices that perform wireless communication with the mobile stations 200-1 and 200-2 located in the service area of the local station, for example.
  • the base stations 100-1 and 100-2 can divide or integrate cells under the base stations 100-1 and 100-2 by changing the antenna configuration. Such division can be realized by AAS, for example.
  • AAS for example.
  • FIG. 2 an example is shown in which one cell under the base station 100-1 is divided into two cells.
  • the base stations 100-1 and 100-2 acquire traffic information related to traffic in the radio section with the mobile stations 200-1 and 200-2.
  • the traffic information may be, for example, the number of packets transmitted / received per unit time or the number of bits (or data amount), the amount of radio resources allocated, the number of retransmissions, the retransmission rate, the handover success rate, and the like.
  • the base station 100-1 acquires traffic information by monitoring wireless communication with the mobile stations 200-1 and 200-2.
  • the base station 100-1 transmits the acquired traffic information to the maintenance system 300 and the access gateway 400 periodically or upon request.
  • the base stations 100-1 and 100-2 can receive an antenna configuration change instruction from the maintenance system 300.
  • Base stations 100-1 and 100-2 change the antenna configuration from the first configuration to the second configuration in accordance with the instruction. By changing the antenna configuration (or by reconfiguring the antenna), each base station 100-1, 100-2 divides one cell under control into two cells, or integrates the two cells. It becomes possible to do.
  • the base stations 100-1 and 100-2 receive from the maintenance system 300 information (or instructions) of the mobile stations 200-1 and 200-2 to be handed over in accordance with the change of the antenna configuration.
  • the mobile station 200-2 located in the new cell after the division is instructed as a mobile station to be handed over.
  • the mobile stations 200-1 and 200-2 are wireless communication devices such as feature phones, smartphones, tablet terminals, personal computers, and game devices, for example.
  • the mobile stations 200-1 and 200-2 perform various services such as a call service and a web page browsing service from the base stations 100-1 and 100-2 within the service areas of the base stations 100-1 and 100-2. Get offered.
  • the base stations 100-1 and 100-2 and the mobile stations 200-1 and 200-2 can perform two-way wireless communication. That is, the direction from the base stations 100-1 and 100-2 to the mobile stations 200-1 and 200-2 (hereinafter sometimes referred to as “downward direction”) and the mobile stations 200-1 and 200-2 to the base station This is a direction toward the stations 100-1 and 100-2 (hereinafter, sometimes referred to as “upward direction”).
  • the base stations 100-1 and 100-2 When the base stations 100-1 and 100-2 perform wireless communication with the mobile stations 200-1 and 200-2, the base stations 100-1 and 100-2 allocate radio resources (time resources, frequency resources, etc.), and modulation methods, coding rates, etc. To decide. Each of the base stations 100-1 and 100-2 transmits a control signal including scheduling information such as radio resource allocation and modulation scheme to the mobile stations 200-1 and 200-2. The base stations 100-1 and 100-2 and the mobile stations 200-1 and 200-2 perform wireless communication according to the scheduling information included in the control signal.
  • the number of base stations and mobile stations is one. It may be one or more than two.
  • the mobile communication system 10 shown in FIG. 2 an example is shown in which two mobile stations 200-1 and 200-2 are connected to the base station 100-1, but the mobile station 200-1 is connected to the base station 100-1.
  • the number of stations may be 1 or 3 or more.
  • the maintenance system 300 is connected to the base station 100-1, but the maintenance system 300 may be connected to the base station 100-2. .
  • the maintenance system 300 is a system that performs maintenance and management of network elements, for example.
  • the maintenance system 300 collects traffic conditions and radio quality information from the base station 100-1.
  • the maintenance system 300 acquires the location information of the mobile stations 200-1 and 200-2 from the location information server 500. Then, maintenance system 300 determines to change the antenna configuration in base station 100-1 from the first configuration to the second configuration based on the traffic information and the location information, and changes the configuration to the second configuration. Instructs the base station 100-1. Maintenance system 300 determines mobile stations 200-1 and 200-2 to be handed over by changing the antenna configuration, and instructs mobile stations 200-1 and 200-2 to be handed over to base station 100-1. To do. A configuration example of the maintenance system 300 will be described later.
  • the access gateway 400 is, for example, a gateway that manages access to the network.
  • the access gateway 400 may be, for example, an MME (Mobility Management Entity), SGW (Serving Gateway), PGW (Packet Data Network Gateway: PDN gateway), or the like.
  • MME Mobility Management Entity
  • SGW Serving Gateway
  • PGW Packet Data Network Gateway: PDN gateway
  • the access gateway 400 can also decide to change the antenna configuration and instruct the base station 100-1.
  • the access gateway 400 acquires the traffic status and the cell configuration list from the base station 100-1, and acquires the location information of the mobile stations 200-1 and 200-2 from the location information server 500. Then, the access gateway 400 determines to change the antenna configuration in the base station 100-1 from the first configuration to the second configuration based on the traffic information and the position information included in the traffic situation.
  • the base station 100-1 may notify the access gateway 400 of the traffic state change as the traffic state, and the access gateway 400 may determine the antenna configuration change based on the state change.
  • the access gateway 400 uses the antenna configuration list to grasp the latest antenna configuration in the base station 100, and determines to change the antenna configuration based on the antenna configuration list. Also good. In this case, after changing the antenna configuration, base station 100 transmits an antenna configuration list indicating the changed antenna configuration to access gateway 400. The access gateway 400 instructs the mobile stations 200-1 and 200-2 to be handed over accompanying the change of the antenna configuration to the base station 100-1. In the following description, the traffic status and the traffic information may be used without being distinguished.
  • the location information server 500 holds location information of the mobile stations 200-1 and 200-2.
  • the mobile stations 200-1 and 200-2 appropriately acquire the position information of the own station by GPS (Global Positioning System).
  • GPS Global Positioning System
  • the location information server 500 can acquire the location information acquired in the mobile stations 200-1 and 200-2 from the mobile stations 200-1 and 200-2 via the base station 100-1 and the access gateway 400. is there.
  • the location information server 500 transmits the location information of the mobile stations 200-1 and 200-2 to the maintenance system 300 and the access gateway 400 in response to requests from the maintenance system 300 and the access gateway 400.
  • the location information server 500 includes a storage device (or memory) such as a hard disk, and the location information of the mobile stations 200-1 and 200-2 is stored in such a storage device.
  • the location information server 500 may collect location information by any of the following three methods, for example. (1) GPS location information notified from the mobile stations 200-1 and 200-2 (A-GNSS (Assisted-Global Navigation Satellite System)) (2) Timing of pilot signals received from a plurality of base stations 100-1 and 100-2 (OTDOA (Observed Time Difference of Arrival)) (3) E-CID (Enhanced-Cell ID) measured by each of the mobile stations 200-1 and 200-2
  • A-GNSS Assisted-Global Navigation Satellite System
  • OTDA Observed Time Difference of Arrival
  • E-CID Enhanced-Cell ID
  • the maintenance system 300 or the base station 100-1 estimates the positions of the mobile stations 200-1 and 200-2 by either of the following.
  • the base station 100-1 instructs the mobile stations 200-1 and 200-2 to measure radio quality information (RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), or path loss). To do. Thereafter, the base station 100-1 estimates the positions of the mobile stations 200-1 and 200-2 by three-point positioning using the radio quality information acquired from the mobile stations 200-1 and 200-1.
  • the base station 100-1 instructs the mobile stations 200-1 and 200-2 to estimate position information, and the mobile stations 200-1 and 200-2 use the wireless quality information to perform three-point positioning. Thus, the positions of the mobile stations 200-1 and 200-2 are estimated.
  • Each mobile station 200-1, 200-2 reports the result to the base station 100-1.
  • the base station 100-1 can also decide to change its own antenna configuration.
  • the base station 100-1 acquires the position information of the mobile stations 200-1 and 200-2 from the position information server 500 via the maintenance system 300, and configures the antenna configuration based on the position information and the traffic information. Decide to change from one configuration to the second configuration.
  • the base station 100-1 may acquire position information from the position information server 500 via the access gateway 400.
  • the base stations 100-1 and 100-2 have the same configuration, they may be described as the base station 100 unless otherwise specified. Further, since the mobile stations 200-1 and 200-2 have the same configuration, they may be described as the mobile station 200 unless otherwise specified.
  • FIG. 3A shows an example of cell division
  • FIG. 3B shows an example of cell integration.
  • FIG. 3A there is shown an example in which there is one cell under the base station 100 and the cell is divided into two cells by cell division.
  • the cell ID (Identity) of the cell before the division is “Cell # 1”, and the cell IDs of the two cells after the division are “Cell # 1” and “Cell # 2”.
  • the cell ID of the cell in which the mobile station 200-2 is located is the same as “Cell # 1” before and after the division and is not changed.
  • the cell ID of the cell in which mobile station 200-1 is located is changed to “Cell # 1” before division and to “Cell # 2” after division.
  • the mobile station 200-1 having the cell ID changed becomes a handover target, and the mobile station 200-2 without the cell ID change does not become a handover target and does not have to be handed over.
  • the base station 100 and the mobile station 200-1 perform handover processing.
  • the change of the cell ID by cell division is an example as described above.
  • the cell IDs of two cells after division may be changed.
  • the cell where the mobile station 200-1 is located is “Cell # 1” to “Cell # 2”
  • the cell where the mobile station 200-2 is located is “Cell # 1” to “Cell # 1”. It may be changed to “Cell # 3”.
  • both the two mobile stations 200-1 and 200-2 are targeted for handover.
  • FIG. 3B there is an example in which there is one cell under the base station 100, and two cells are integrated into one cell by cell integration.
  • the cell ID of the cell where the mobile station 200-1 is located before the integration is “Cell # 2”
  • the cell ID of the cell where the mobile station 200-2 is located is “Cell # 1”. Both are changed to “Cell # 1”.
  • the mobile station 200-1 since the cell ID of the cell where the mobile station 200-1 is located is changed, the mobile station 200-1 becomes a target for handover, and the cell ID of the cell where the mobile station 200-2 is located is not changed. 200-2 is not a handover target.
  • the change of the cell ID by the cell integration is an example, and any cell ID may be changed by the cell integration as shown in FIG. 3B.
  • any of the mobile stations 200-1, 200-2 Are also subject to handover.
  • FIG. 4 is a diagram illustrating a configuration example of the base station 100.
  • the base station 100 includes an antenna 101, a reception radio unit 102, a reception multiple access processing unit 103, a demodulation / decoding unit 104, a control signal processing unit 105, a cell division / integration control unit (or a cell division / integration control unit. It may be referred to as a “cell control unit”.) 106 and an antenna control unit 107 are provided.
  • the base station 100 includes a traffic information management unit 108, a mobile station location information management unit 109, a TCP / IP (Transmission Control Protocol / Internet Protocol) transmission / reception unit 110, a transmission power control unit 111, an encoding / modulation unit 112, a transmission A multiple access processing unit 113 and a transmission wireless unit 114 are provided.
  • a traffic information management unit 108 a mobile station location information management unit 109, a TCP / IP (Transmission Control Protocol / Internet Protocol) transmission / reception unit 110, a transmission power control unit 111, an encoding / modulation unit 112, a transmission A multiple access processing unit 113 and a transmission wireless unit 114 are provided.
  • TCP / IP Transmission Control Protocol / Internet Protocol
  • the base station 100 may include the AAS 120.
  • the transceiver unit 125-1 includes the reception radio unit 102 and the transmission radio unit 114, and the antenna (or antenna element, which may be referred to as “antenna element” hereinafter) 126-1 includes the antenna 101. Is included.
  • the transceiver unit 125-1 and the antenna element 126-1 become one set 125-1, 126-1, and the AAS 120 has a plurality of sets 125-1, 126-1, 125-2, 126-2,. included.
  • the reception radio unit 102 and the transmission radio unit 114 in each of the transceiver units 125-1, 125-2,... Are connected to the reception multiple access processing unit 103 and the transmission multiple access processing unit 113, respectively.
  • the antenna control unit 107 controls the reception radio unit 102 and the transmission radio unit 114 in each of the transceiver units 125-1, 125-2,.
  • the plurality of transceiver units 125-1, 125-2,... Is a transceiver unit array, the plurality of antenna elements 126-1, 126-2,... Are antenna arrays, and the AAS 120 includes a transceiver unit array and an antenna array. May be.
  • the base station 100 includes a BBU (Base Band Unit) 121.
  • the BBU 121 and the AAS 120 may be connected by an optical fiber cable.
  • the BBU 121 includes a reception multiple access processing unit 103, a demodulation / decoding unit 104, a control signal processing unit 105, a cell control unit 106, a traffic information management unit 108, and a mobile station location information management unit 109.
  • the BBU 121 includes a TCP / IP transmission / reception unit 110, a transmission power control unit 111, an encoding / modulation unit 112, and a transmission multiple access processing unit 113.
  • the BBU 121 and the AAS 120 may be installed at physically separated positions such as several meters to several kilometers.
  • the traffic information management unit 170 and the transmission / reception unit 171 in the first embodiment correspond to, for example, the traffic information management unit 108 and the TCP / IP transmission / reception unit 110, respectively.
  • the control unit 172 in the first embodiment corresponds to, for example, the cell control unit 106 and the antenna control unit 107.
  • the antenna 101 receives a radio signal transmitted from the mobile station 200 and outputs the received radio signal to the reception radio unit 102. Further, the antenna 101 transmits the radio signal output from the transmission radio unit 114 to the mobile station 200.
  • the reception radio unit 102 converts the radio signal in the radio band received from the antenna 101 into a baseband signal in the baseband band (down-conversion). Reception radio section 102 outputs the converted baseband signal to reception multiple access processing section 103.
  • the reception multiple access processing unit 103 performs S / P (Serial-to-Parallel) conversion processing, FFT (Fast-Fourier Transform) processing, and the like on the baseband signal.
  • the reception multiple access processing unit 103 then separates the multiplexed signals based on information such as radio resources received from the cell control unit 106 and the like.
  • Reception multiple access processing section 103 outputs the separated signal to demodulation / decoding section 104 as a received signal.
  • Demodulation / decoding section 104 performs demodulation processing and error correction decoding processing on the received signal received from reception multiple access processing section 103 according to the modulation scheme and coding rate received from cell control section 106, etc. Data and control signals transmitted from the station 200 are reproduced.
  • the demodulation / decoding unit 104 outputs data to an application processing unit and the like, and outputs a control signal to the control signal processing unit 105.
  • the control signal processing unit 105 extracts information included in the control signal from the control signal received from the demodulation / decoding unit 104. Examples of information included in the control signal include information indicating handover completion.
  • the control signal processing unit 105 outputs the extracted information to the cell control unit 106.
  • Control signal processing section 105 generates a control signal in accordance with an instruction from cell control section 106 and outputs the generated control signal to transmission power control section 111. Examples of instructions from the cell control unit 106 include a handover instruction and a scheduling information creation instruction, and the control signal processing unit 105 may generate a control signal including such an instruction.
  • the cell control unit 106 controls cell division and cell integration by antenna reconfiguration. For example, the cell control unit 106 notifies the antenna control unit 107 of the changed configuration of the antenna 101 according to the antenna configuration change instruction received from the maintenance system 300 or the access gateway 400 via the TCP / IP transmission / reception unit 110. Alternatively, the cell control unit 106 receives traffic information regarding traffic to and from the mobile station 200 from the traffic information management unit 108, receives location information of the mobile station 200 from the mobile station location information management unit 109, and receives traffic information and location information. Change the cell configuration based on The cell control unit 106 notifies the antenna control unit 107 of the changed cell configuration. In addition, the cell control unit 106 transmits an antenna configuration list indicating the current configuration of the cell due to, for example, a change in the antenna configuration to the access gateway 400 via the TCP / IP transmission / reception unit 110. Also good.
  • the antenna control unit 107 controls the reception radio unit 102 and the transmission radio unit 114.
  • the antenna control unit 107 may instruct the reception radio unit 102 and the transmission radio unit 114 to change the beamforming according to an instruction from the cell control unit 106.
  • the antenna control unit 107 may instruct to change the tilt angle of the antenna 101 via the reception radio unit 102 or the transmission radio unit 114 in accordance with an instruction from the cell control unit 106.
  • the antenna control unit 107 may directly control the antenna 101 so as to change the tilt angle.
  • the traffic information management unit 108 manages traffic information related to traffic between the base station 100 and the mobile station 200.
  • the traffic information management unit 108 may acquire the traffic information by monitoring data output from the demodulation unit / decoding unit 104 or data input to the encoding / modulation unit 112.
  • the traffic information management unit 108 may acquire the radio resource scheduled by the cell control unit 106 from the cell control unit 106 and acquire the traffic information based on the radio resource.
  • the traffic information management unit 108 may periodically transmit the acquired traffic information to the maintenance system 300 or the access gateway 400 via the TCP / IP transmission / reception unit 110.
  • the traffic information management unit 108 may output the acquired traffic information to the cell control unit 106.
  • the mobile station location information management unit 109 manages the location information of the mobile station 200 acquired via the TCP / IP transmission / reception unit 110. For example, the mobile station location information management unit 109 generates a location information acquisition request in accordance with an instruction from the cell control unit 106 and outputs the location information acquisition request to the TCP / IP transmission / reception unit 110.
  • the position information acquisition request is transmitted to the position information server 500 via the maintenance system 300 or the access gateway 400, and the position information server 500 transmits the position information to the base station 100 via the maintenance system 300 or the access gateway 400.
  • the mobile station location information management unit 109 holds, for example, the acquired location information of the mobile station 200 in the internal memory, or outputs it to the cell control unit 106 in accordance with an instruction from the cell control unit 106.
  • the TCP / IP transmission / reception unit 110 is connected to the maintenance system 300 and the access gateway 400, and exchanges TCP packets with the maintenance system 300 and the access gateway 400.
  • the TCP / IP transmission / reception unit 110 receives a TCP packet transmitted from the maintenance system 300, and extracts a cell configuration change instruction, information on the handover target mobile station 200, location information of the mobile station 200, and the like from the TCP packet. To do.
  • the TCP / IP transmission / reception unit 110 outputs a cell configuration change instruction and handover target mobile station 200 information to the cell control unit 106, and mobile station 200 location information to the mobile station location information management unit 109.
  • the TCP / IP transmission / reception unit 110 receives traffic information from the traffic information management unit 108, a location information acquisition request from the mobile station location information management unit 109, etc., and receives a TCP packet including these pieces of information according to instructions from the cell control unit 106. It is generated and transmitted to the maintenance system 300 and the access gateway 400.
  • the transmission power control unit 111 receives transmission data, a control signal, and the like, and outputs transmission data, a control signal, and the like to the encoding / modulation unit 112 with transmission power according to the transmission power control value received from the cell control unit 106 or the like. .
  • the coding / modulation unit 112 performs error correction coding processing and modulation processing on the transmission data and control signal received from the transmission power control unit 111 according to the coding rate and modulation method received from the cell control unit 106 and the like. Etc.
  • the encoding / modulation unit 112 outputs the transmission data after the modulation processing as a transmission signal.
  • the transmission multiple access processing unit 113 performs IFFT (Inverse Fast Fourier Transfer) processing, P / S (Parallel to Serial) conversion processing, and the like on the transmission signal output from the encoding / modulation unit 112 to perform multiple access. (For example, an OFDMA (Orthogonal Frequency-Division Multiple Access) signal). Transmission multiple access processing section 113 outputs the converted transmission signal to transmission radio section 114.
  • IFFT Inverse Fast Fourier Transfer
  • P / S Parallel to Serial
  • OFDMA Orthogonal Frequency-Division Multiple Access
  • the transmission radio unit 114 converts the transmission signal output from the transmission multiple access processing unit 113 into a radio signal by performing frequency conversion processing based on the frequency received from the cell control unit 106 or the like (up-conversion). To do. Transmission radio section 114 outputs a radio signal to antenna 101.
  • FIG. 5 is a diagram illustrating a configuration example of the mobile station 200.
  • the mobile station 200 includes an antenna 201, a reception radio unit 202, a reception multiple access processing unit 203, a demodulation / decoding unit 204, a control signal extraction unit 205, a handover control unit for cell division / integration (or a handover control unit for cell division and integration).
  • a handover controller for handover control unit for cell division / integration
  • the mobile station 200 includes a synchronization processing unit 207, a rollback control unit 208, a control signal processing unit 209, a transmission power control unit 210, an encoding / modulation unit 211, a transmission multiple access processing unit 212, and a transmission radio unit 213. .
  • the antenna 201 receives a radio signal transmitted from the base station 100 and outputs the received radio signal to the reception radio unit 202. Further, the antenna 201 receives the radio signal output from the transmission radio unit 213 and transmits the received radio signal to the base station 100.
  • the reception radio unit 202 performs amplification processing and frequency conversion processing on the radio signal based on the frequency received from the control signal extraction unit 205 or the like to convert the radio signal in the radio band into the radio signal in the baseband ( Down-convert).
  • Reception radio section 202 outputs the baseband signal to reception multiple access processing section 203.
  • the reception multiple access processing unit 203 performs A / D conversion processing, S / P conversion processing, FFT processing, and the like on the baseband signal to separate multiplexed baseband signals.
  • reception multiple access processing section 203 separates the baseband signal assigned to the own station according to the radio resource received from control signal extraction section 205.
  • Reception multiple access processing section 203 outputs the separated baseband signal to demodulation / decoding section 204 as a received signal.
  • Demodulation / decoding section 204 performs demodulation processing and error correction decoding processing on the received signal according to the modulation scheme and coding rate received from control signal extraction section 205, respectively, and transmits data and control transmitted from base station 100. Play the signal.
  • the control signal extraction unit 205 extracts a control signal from the output from the demodulation / decoding unit 204.
  • the control signal includes, for example, information indicating a handover instruction and scheduling information.
  • the control signal extraction unit 205 outputs the extracted control signal to the handover control unit 206.
  • the handover control unit 206 controls the handover in the mobile station 200 according to the control signal.
  • the handover control unit 206 instructs the synchronization processing unit 207 to perform the synchronization process during the handover process. Details of processing in the handover control unit 206 will be described in an operation example.
  • the synchronization processing unit 207 performs synchronization processing with the handover destination cell in accordance with an instruction from the handover control unit 206.
  • the synchronization processing unit 207 instructs the rollback control unit 208 to perform loadback control.
  • the synchronization processing unit 207 instructs the control signal processing unit 209 to generate a handover completion notification when the synchronization process is successfully performed on the handover destination cell.
  • the synchronization processing unit 207 may instruct the control signal processing unit 209 to generate a synchronization establishment processing request or the like during the synchronization processing.
  • the rollback control unit 208 controls each unit in the mobile station 200 according to the instruction from the synchronization processing unit 207 so that the mobile station 200 rolls back to the handover source cell.
  • the rollback is, for example, to return to the state before the handover, and to return the connection to the cell before the division even when the cell division fails. By rolling back, the mobile station 200 can connect to the original cell before division without performing reconnection processing to the cell before division.
  • the control signal processing unit 209 generates a control signal according to an instruction from the synchronization processing unit 207, and outputs the generated control signal to the transmission power control unit 210.
  • the control signal may include, for example, information indicating completion of handover or a synchronization establishment processing request.
  • the transmission power control unit 210 receives transmission data, control signals, etc., and encodes transmission data, control signals, etc. with transmission power according to the transmission power control values received from the control signal extraction unit 205, the handover control unit 206, etc.
  • the data is output to the modulation unit 211.
  • the coding / modulation unit 211 performs error correction coding processing, modulation processing, etc. on the transmission data output from the transmission power control unit 210 according to the coding rate and modulation method received from the control signal extraction unit 205, etc. Are applied respectively.
  • the encoding / modulation unit 211 outputs modulated transmission data and the like as a transmission signal.
  • the transmission multiple access processing unit 212 performs IFFT processing, P / S conversion processing, and the like on the transmission signal output from the encoding / modulation unit 211 to a signal corresponding to multiple access (for example, an OFDMA signal). Convert.
  • the transmission multiple access processing unit 212 outputs the converted transmission signal to the transmission radio unit 213.
  • the transmission radio unit 213 converts the transmission signal received from the transmission multiple access processing unit 212 into a radio signal by performing frequency conversion processing or amplification processing based on the frequency received from the control signal extraction unit 205 or the like. Convert). Transmission radio section 213 outputs a radio signal to antenna 201.
  • FIG. 6 is a diagram illustrating a configuration example of the maintenance system 300.
  • the maintenance system 300 includes a TCP / IP transmission / reception unit 301 for a base station, a signal analysis unit 302, a traffic information management unit 303, a TCP / IP transmission / reception unit 304 for a location information server, a signal analysis unit 305, and a mobile station location information management unit 306.
  • the maintenance system 300 includes a cell division / integration (antenna configuration) determination unit / mobile station determination unit (cell division / integration (antenna configuration) determination unit and mobile station determination unit.
  • a determination unit determination unit
  • mobile station determination unit mobile station determination unit
  • the transmission / reception unit 610 in the first embodiment corresponds to, for example, the TCP / IP transmission / reception unit 301 for base station and the TCP / IP transmission / reception unit 304 for location information server.
  • the determination unit 620 in the first embodiment corresponds to the determination unit 307, for example.
  • the base station TCP / IP transmission / reception unit 301 exchanges TCP packets with the base station 100. That is, the TCP / IP transmission / reception unit 301 for the base station receives the TCP packet transmitted from the base station 100, extracts traffic information and radio quality information from the received TCP packet, and signals the extracted traffic information and the like. The data is output to the analysis unit 302. Further, the TCP / IP transmission / reception unit 301 for the base station receives the cell configuration change instruction output from the determination unit 307, generates a TCP packet including the information, and transmits the generated TCP packet to the base station 100. To do.
  • the signal analysis unit 302 receives the traffic information output from the TCP / IP transmission / reception unit 301 for the base station, and outputs the received information to the traffic information management unit 303.
  • the traffic information management unit 303 manages traffic information transmitted from the base station 100.
  • the traffic information management unit 303 may appropriately store the traffic information received from the signal analysis unit 302 in the internal memory or output the traffic information to the determination unit 307.
  • the location information server TCP / IP transmission / reception unit 304 exchanges TCP packets with the location information server 500. That is, the TCP / IP transmission / reception unit 304 for the location information server receives the TCP packet transmitted from the location information server 500, extracts the location information of the mobile station 200 from the received TCP packet, and extracts the extracted location information and the like. Output to the signal analysis unit 305.
  • the signal analysis unit 305 receives the location information from the TCP / IP transmission / reception unit 304 for the location information server, and outputs the received location information to the mobile station location information management unit 306.
  • the mobile station location information management unit 306 manages the location information of the mobile station 200 transmitted from the location information server 500.
  • the mobile station location information management unit 306 may appropriately store the location information received from the signal analysis unit 305 in an internal memory or transmit the location information to the determination unit 307.
  • the determination unit 307 changes the cell configuration in the base station 100 from the first configuration to the second configuration based on the traffic information received from the traffic information management unit 303 and the location information received from the mobile station location information management unit 306. Decide what to do.
  • the determination unit 307 outputs a change instruction to the second configuration and a list of mobile stations that need to move to a new cell due to the change to the TCP / IP transmission / reception unit 301 for the base station.
  • FIG. 7 is a diagram illustrating a configuration example of the access gateway 400.
  • the access gateway 400 includes a base station TCP / IP transmission / reception unit 401, a signal analysis unit 402, a traffic information management unit 403, a location information server TCP / IP transmission / reception unit 404, a signal analysis unit 405, and a mobile station location information management unit 406.
  • the access gateway 400 includes a cell division / integration (antenna configuration) determination unit / mobile station determination unit (or a cell division / integration (antenna configuration) determination unit and a mobile station determination unit; hereinafter referred to as a “determination unit”). 407 is provided.
  • the transmission / reception unit 610 in the first embodiment corresponds to, for example, the TCP / IP transmission / reception unit 401 for base stations and the TCP / IP transmission / reception unit 404 for location information servers.
  • the determination unit 620 in the first embodiment corresponds to the determination unit 407, for example.
  • the base station TCP / IP transceiver 401 exchanges TCP packets with the base station 100. That is, the TCP / IP transmission / reception unit 401 for the base station receives the TCP packet transmitted from the base station 100, extracts a load state change notification, an antenna configuration list, and the like from the received TCP packet, and extracts the load state change Notification or the like is output to the signal analysis unit 402. Also, the base station TCP / IP transceiver 401 receives the cell configuration change instruction output from the determination unit 407, generates a TCP packet including these pieces of information, and transmits the generated TCP packet to the base station 100. To do.
  • the signal analysis unit 402 receives the load state change notification output from the TCP / IP transmission / reception unit 401 for the base station, and outputs the received load state change notification to the traffic information management unit 403.
  • the traffic information management unit 403 manages the load state change notification and the antenna configuration list transmitted from the base station 100.
  • the traffic information management unit 403 may appropriately store the load state change notification, the antenna configuration list, and the like received from the signal analysis unit 402 in the internal memory or may output them to the determination unit 307.
  • the location information server TCP / IP transmission / reception unit 404 exchanges TCP packets with the location information server 500. That is, the TCP / IP transmission / reception unit 404 for the location information server receives the TCP packet transmitted from the location information server 500, extracts the location information of the mobile station 200 from the received TCP packet, and extracts the extracted location information, etc. Output to the signal analysis unit 405.
  • the signal analysis unit 405 receives the location information output from the TCP / IP transmission / reception unit 404 for the location information server, and outputs the received location information to the mobile station location information management unit 406.
  • the mobile station location information management unit 406 manages the location information of the mobile station 200 transmitted from the location information server 500.
  • the mobile station location information management unit 406 may appropriately store the location information received from the signal analysis unit 405 in an internal memory or output the location information to the determination unit 407.
  • the determination unit 407 changes the cell configuration in the base station 100 from the first configuration to the second configuration based on the load state change notification received from the traffic information management unit 403 and the location information received from the mobile station location information management unit 406. Decide to change to The determination unit 407 outputs a change instruction to the second configuration and a list of mobile stations that need to move to a new cell due to the change to the TCP / IP transmission / reception unit 401 for the base station.
  • the maintenance system 300 and the base station 100 have a function of collecting traffic information in the base station 100. Based on the collected traffic information, the maintenance system 300 and the base station 100 determine whether or not the traffic state between the base station 100 and the mobile station 200 has transitioned from the normal state to the congestion state, or from the congestion state to the normal state. It is determined whether or not a state transition has been made. In this case, when the value indicated by the traffic information exceeds the congestion state threshold, the maintenance system 300 and the base station 100 detect that the state transition from the normal state to the congestion state.
  • the maintenance system 300 and the base station 100 detect that the state transition has been made from the congestion state to the normal state when the value indicated by the traffic information becomes lower than the normal state threshold (or the mitigation state threshold).
  • the relationship between the two thresholds may be, for example, congestion state threshold> normal state threshold. With this relationship, it is possible to prevent frequent occurrence of state changes such as from the normal state to the congestion state and from the congestion state to the normal state.
  • the maintenance system 300 or the base station 100 determines to divide the cells under the base station 100.
  • the maintenance system 300 and the base station 100 detect the positional deviation of the mobile station 200 based on the positional information acquired from the positional information server 500, and an antenna that performs optimal cell division against such deviation. Determine the configuration.
  • the number of cells under the base station 100 increases.
  • the number of mobile stations 200 that can be controlled (or accommodated) under the base station 100 also increases, and the cell capacity of the base station 100 increases. By expanding the cell capacity, the base station 100 can cope with the congestion state.
  • the maintenance system 300 and the base station 100 can appropriately increase the cell capacity by determining the antenna configuration that provides the optimum cell division.
  • the maintenance system 300 or the base station 100 determines to integrate cells under the base station 100.
  • the maintenance system 300 and the base station 100 detect the positional deviation of the mobile station 200 based on the positional information acquired from the positional information server 500, and have an antenna configuration that provides optimum cell integration for such deviation. You may decide.
  • the base station 100 reduces the cell capacity and restores the configuration of the divided cells. Thereby, for example, since the number of cells accommodated in the base station 100 is reduced, it is possible to reduce the frequency of handover and to reduce the interference generated between the cells.
  • the maintenance system 300 and the base station 100 can appropriately increase the cell capacity by determining the antenna configuration that provides the optimum cell division.
  • the maintenance system 300 and the base station 100 can appropriately control the cell capacity, for example, by changing the cell configuration based on the traffic information and the location information.
  • the determination of cell division or integration may be further performed in the access gateway 400.
  • the access gateway 400 also collects traffic information and detects a state transition using a congestion state threshold or a normal state threshold.
  • processing related to cell division and integration determination is performed in the maintenance system 300 and the access gateway 400, so that, for example, operability and maintainability are compared with the case where the processing is performed in a plurality of base stations 100. Efficient management is possible.
  • FIG. 8 is a flowchart showing an operation example when cell division processing is performed by the base station.
  • the base station 100 When the base station 100 starts processing (S10), it collects traffic information regarding traffic between the base station 100 and the mobile station 200 (S11). For example, the traffic information management unit 108 may collect traffic information based on the amount of data output from the demodulation / decoding unit 104. Alternatively, the traffic information acquired by the mobile station 200 may be acquired from the mobile station 200, and the traffic information management unit 108 may acquire the traffic information output from the demodulation / decoding unit 104.
  • the base station 100 determines whether or not the traffic state between the base station 100 and the mobile station 200 has changed from the normal state to the congestion state based on the collected traffic information (S12). For example, the cell control unit 106 detects that the state transition from the normal state to the congestion state occurs when the value indicated by the traffic information acquired from the traffic information management unit 108 exceeds the congestion state threshold (or the first threshold). When the value is equal to or less than the congestion state threshold value, it may be detected that the normal state is maintained.
  • the target of the state transition may be, for example, a load in a cell under the base station 100 or a load of the base station 100 itself, and such a load in the base station 100 has exceeded a congestion state threshold. It is sufficient if it can be detected. The same applies to the following.
  • the base station 100 determines to divide the cells under the base station 100 (S13). For example, when the cell control unit 106 detects that the traffic state has changed to a congestion state, the cell control unit 106 determines cell division.
  • the base station 100 requests the maintenance system 300 or the access gateway 400 to collect location information of the mobile station 200 (S14).
  • the cell control unit 106 instructs the mobile station location information management unit 109 to collect location information, and the mobile station location information management unit 109 sends the location information collection instruction via the TCP / IP transmission / reception unit 110. 300 or access gateway 400.
  • the collection instruction is transmitted to the location information server 500 via the maintenance system 300 or the access gateway 400.
  • the base station 100 receives the position information from the maintenance system 300 or the access gateway 400 after the maintenance system 300 or the access gateway 400 acquires the position information from the position information server 500 (S15).
  • the location information server 500 transmits the location information of the corresponding mobile station 200 to the maintenance system 300 or the access gateway 400 according to the collection instruction, and the maintenance system 300 or the access gateway 400 transmits the received location information to the base station 100.
  • the mobile station location information management unit 109 receives location information transmitted from the maintenance system 300 or the access gateway 400 via the TCP / IP transmission / reception unit 110, and outputs the received location information to the cell control unit 106.
  • the base station 100 determines an antenna configuration that is optimally divided from the distribution status of the mobile stations 200 (S16). For example, when the cell control unit 106 detects that the load of the base station 100 exceeds the congestion state threshold based on the traffic information, the cell control unit 106 changes the antenna configuration from the first configuration to the second configuration based on the position information. By changing, it is determined to divide cells under the base station 100. For example, the cell control unit 106 determines the bias of the mobile station 200 from the position information of each mobile station 200 at the time when the traffic volume exceeds the congestion state threshold, and determines the antenna configuration that is the optimal cell configuration. In this case, the cell control unit 106 may determine the antenna configuration so that, for example, the number of mobile stations 200 arranged in each divided cell is uniform.
  • the base station 100 determines the mobile station 200 to be arranged in the new cell based on the location information (S16).
  • the cell control unit 106 may determine the mobile station 200 located in the cell whose cell ID has been changed in each divided cell based on the location information.
  • the base station 100 executes handover control for the mobile station 200 to a new cell (S18).
  • the cell control unit 106 instructs the antenna control unit 107 to divide the cell, and instructs the control signal processing unit 105 to execute handover to the mobile station 200 arranged in the new divided cell.
  • the base station 100 performs handover processing by exchanging control signals with the mobile station 200 via the control signal processing unit 105.
  • the base station 100 ends a series of processes (S19).
  • the base station 100 detects that the traffic state has not changed from the normal state to the congestion state (No in S12), the base station 100 ends the series of processing without performing processing such as cell division (S19). .
  • FIG. 9 is a flowchart showing an operation example when cell division processing is performed under the initiative of the maintenance system 300.
  • the maintenance system 300 When the maintenance system 300 starts processing (S30), it collects traffic information from the base station 100 (S31). For example, the traffic information management unit 303 collects traffic information transmitted from the base station 100 by receiving it.
  • the maintenance system 300 determines whether or not the traffic state between the base station 100 and the mobile station 200 has transitioned from the normal state to the congestion state (S32). For example, the determination unit 307 detects a state transition from the normal state to the congestion state when the value indicated by the traffic information acquired from the traffic information management unit 303 exceeds the congestion state threshold, and the value is equal to or less than the congestion state threshold. Sometimes it may be detected that the normal state is maintained.
  • the maintenance system 300 determines to divide the cell under the base station 100 (S33), and from the location information server 500 to the mobile station The position information of 200 is acquired (S34). For example, when the determination unit 305 detects a state transition to a congestion state, it determines cell division, instructs the mobile station location information management unit 306 to acquire location information, and the mobile station location information management unit 306 The position information is acquired from the server 500.
  • the maintenance system 300 determines an antenna configuration that is optimally divided from the distribution status of the mobile station 200 (S35). For example, when the determination unit 307 detects that the load of the base station 100 has exceeded the congestion state threshold based on the traffic information, similarly to the cell control unit 106, the determination unit 307 sets the first antenna configuration based on the position information. It is determined to change the configuration to the second configuration and divide the cells under the base station. In this case, the determination unit 307 analyzes the bias of the mobile station 200 based on the position information, and determines an antenna configuration that is optimally divided. The determination unit 307 may determine the antenna configuration so that the number of mobile stations 200 arranged in each divided cell is uniform, as in the case of the base station initiative (for example, S16).
  • the base station initiative for example, S16
  • the maintenance system 300 determines the mobile station 200 to be placed in a new cell and to be handed over from the location information (S36). For example, the determination unit 307 determines the mobile station 200 located in the cell whose cell ID has been changed in each divided cell based on the position information.
  • the maintenance system 300 instructs the determined antenna configuration and the mobile station 200 to be handed over to the base station 100 (S37).
  • the determination unit 307 transmits the changed antenna configuration corresponding to the cell division to the base station 100 via the base station-oriented TCP / IP transmission / reception unit 301.
  • the determination unit 307 transmits the handover target mobile station list including the handover target mobile station 200 determined in S36 to the base station 100 via the base station TCP / IP transmission / reception unit 301.
  • the mobile station 200 included in the list is processed as a handover target mobile station.
  • the maintenance system 300 instructs the base station 100 to execute handover control to the handover target mobile station 200 (S38).
  • the determination unit 307 instructs the base station 100 via the base station TCP / IP transmission / reception unit 301 to perform handover to the mobile station 200.
  • the base station 100 executes handover control for the mobile station 200 to be handed over.
  • the maintenance system 300 detects that the traffic state has not changed from the normal state to the congestion state (No in S32), the maintenance system 300 ends the series of processes without determining the cell division (S39).
  • FIG. 10 is a flowchart showing an operation example when cell division is performed under the initiative of the access gateway 400.
  • the base station 100 collects traffic information (S51).
  • the base station 100 determines whether or not the traffic state has changed from the normal state to the congestion state (S52).
  • the base station 100 When the base station 100 detects that the traffic state has transitioned from the normal state to the congestion state (Yes in S52), the base station 100 generates a load state change notification indicating that the traffic state has changed from the normal state to the congestion state. A notification is transmitted to the access gateway 400 (S53). For example, when detecting a state transition to a congestion state, the cell control unit 106 generates a load state change notification and transmits the generated load state change notification to the access gateway 400 via the TCP / IP transmission / reception unit 110.
  • the access gateway 400 decides to divide the cell under the base station 100 because the traffic state changes from the normal state to the congestion state based on the load state change notification (S54).
  • the determination unit 407 receives a load state change notification from the traffic information management unit 403, and determines cell division based on the notification.
  • the access gateway 400 acquires the location information of the mobile station 200 from the location information server 500 (S55).
  • the mobile station location information management unit 406 acquires location information from the location information server 500 via the location information server-oriented TCP / IP transmission / reception unit 404 and the like.
  • the access gateway 400 determines an antenna configuration that is optimally divided from the distribution status of the mobile station 200 (S56). For example, when the determination unit 407 detects that the load of the base station 100 exceeds the congestion state threshold based on the traffic information, similarly to the cell control unit 106, the determination unit 407 sets the first antenna configuration based on the position information. It is determined to change the configuration to the second configuration and divide the cells under the base station. In this case, the determination unit 407 analyzes the bias of the mobile station 200 based on the position information, and determines an antenna configuration that is optimally divided. The determination unit 407 may determine the antenna configuration so that the number of mobile stations 200 arranged in each divided cell is uniform, as in the case of the base station initiative (for example, S16).
  • the base station initiative for example, S16
  • the access gateway 400 determines the handover target mobile station 200 to be arranged in the new cell from the location information (S57). For example, the determination unit 407 determines the mobile station 200 located in the cell whose cell ID has been changed in each divided cell based on the location information.
  • the access gateway 400 transmits the antenna configuration (or the instruction to change to the second configuration) and information on the mobile station 200 to be handed over to the base station 100 (S58).
  • the determination unit 407 uses the TCP / IP transmission / reception unit 401 for the base station to transmit information regarding the antenna configuration (or the instruction to change to the second configuration) corresponding to the divided cells and the mobile station 200 to be handed over determined in S57. To the base station 100.
  • the access gateway 400 instructs the base station 100 to execute handover control to the new cell for the mobile station 200 to be handed over (S59).
  • the determination unit 407 instructs the base station 100 via the TCP / IP transmission / reception unit 401 for the base station to execute handover for the mobile station 200.
  • the access gateway 400 ends a series of processes (S60).
  • the access gateway 400 when the access gateway 400 does not receive the load state change notification indicating the state transition from the normal state to the congestion state from the base station 100 (No in S52), the access gateway 400 performs a series of processes without performing the process such as the determination of the antenna configuration. The process is terminated (S60).
  • FIG. 11 is a flowchart showing an operation example when cell integration is performed under the initiative of a base station.
  • the base station 100 When the base station 100 starts processing (S70), it collects traffic information (S72).
  • the base station 100 determines whether or not the traffic state has changed from the congestion state to the normal state based on the traffic information (S72). For example, the cell control unit 106 detects a state transition from the congestion state to the normal state when the value indicated by the traffic information becomes smaller than the normal state threshold, and the congestion state is maintained when the value is equal to or greater than the normal state threshold. Detect that The target of the state transition may be, for example, a load in a cell under the base station 100 or a load of the base station 100 itself, as long as it can detect that such a load in the base station 100 has decreased. The same applies to the following.
  • the base station 100 determines to integrate cells under the base station 100 (S73). For example, when the cell control unit 106 detects a transition from a congestion state to a normal state, the cell control unit 106 determines to integrate cells.
  • the base station 100 requests the maintenance system 300 or the access gateway 400 to collect location information of the mobile station 200 (S74).
  • the base station 100 receives the position information by transmitting the acquired position information to the base station 100 (S75). .
  • the base station 100 is located in the cell to be integrated and extracts the mobile station 200 to be handed over (S76).
  • the cell control unit 106 extracts the mobile station 200 located in the cell whose cell ID is changed in the cell after integration based on the location information of the mobile station 200 acquired from the mobile station location information management unit 109. May be.
  • such a mobile station 200 can be a handover target after cell integration.
  • the base station 100 executes handover control to the cell after integration for the mobile station 200 to be handed over (S77).
  • the cell control unit 106 instructs the antenna control unit 107 to perform cell integration, and instructs the control signal processing unit 105 to execute handover to the mobile station 200 that is a handover target in the integrated cell.
  • the base station 100 performs handover processing by exchanging control signals with the mobile station 200 via the control signal processing unit 105.
  • the base station 100 detects that the traffic state has not changed from the congestion state to the normal state (No in S72), the base station 100 ends the series of processes without performing cell integration (S78).
  • FIG. 12 is a flowchart showing an operation example when cell integration is performed under the initiative of the maintenance system 300.
  • the maintenance system 300 When the maintenance system 300 starts processing (S90), it collects traffic information from the base station 100 (S91), and determines whether the traffic status has changed from a congestion state to a normal state based on the collected traffic information. (S92). For example, the determination unit 307 detects a state transition from the congestion state to the normal state when the value indicated by the traffic information becomes smaller than the normal state threshold, and the congestion state is maintained when the value is equal to or greater than the normal state threshold. Detect that.
  • the maintenance system 300 When the maintenance system 300 detects a state transition from the congestion state to the normal state (S92), the maintenance system 300 determines cell integration (S93), and acquires the location information of the mobile station 200 from the location information server 500 (S95). For example, the determination unit 307 determines to integrate the divided cells and return to the cell before the division, and acquires the location information of the mobile station 200 via the mobile station location information management unit 306.
  • the maintenance system 300 extracts the mobile station 200 located in the cell to be integrated (S96).
  • the determination unit 307 extracts the mobile station 200 residing in the cell whose cell ID is changed in the integrated cell based on the location information of the mobile station 200 acquired from the mobile station location information management unit 306. Also good.
  • such a mobile station 200 can be a handover target after cell integration.
  • the maintenance system 300 instructs the base station 100 of the determined antenna configuration and the mobile station 200 to be handed over (S97).
  • the determination unit 307 transmits, to the base station 100, the antenna configuration corresponding to the integrated cell and the handover target mobile station list including the information of the mobile station 200 extracted in S96.
  • the maintenance system 300 instructs the base station 100 to execute handover to the cell after integration for the mobile station 200 to be handed over (S98).
  • the determination unit 307 instructs the base station 100 to handover the handover target mobile station 200 to the integrated cell.
  • the maintenance system 300 detects that the traffic state has not changed from the congestion state to the normal state (No in S92), the maintenance system 300 ends the series of processing without performing processing such as cell integration (S99). .
  • FIG. 13 is a flowchart showing an operation example when cell integration is performed under the initiative of the access gateway.
  • the base station 100 collects traffic information (S111), and determines whether the traffic status has changed from the congestion state to the normal state based on the traffic information (S111). S112).
  • the base station 100 determines the state transition from the congestion state to the normal state (Yes in S112), the base station 100 transmits a load state change notification indicating the state transition from the congestion state to the normal state to the access gateway 400.
  • the cell control unit 106 detects a state transition from the congestion state to the normal state based on the congestion state threshold, the cell control unit 106 generates a load state change notification indicating the state transition from the congestion state to the normal state, and the TCP / IP transmission / reception unit 110.
  • the access gateway 400 receives a load state change notification indicating the state transition from the congestion state to the normal state.
  • the access gateway 400 determines the integration of the cells under the base station 100 (S113). For example, the determination unit 407 may determine to integrate the divided cells and return to the cell before the division.
  • the access gateway 400 acquires the location information of the mobile station 200 from the location information server 500 (S115), and extracts the mobile station 200 located in the integrated cell based on the location information (S116).
  • the determination unit 407 may extract the mobile station 200 residing in the cell whose cell ID is changed in the integrated cell based on the location information.
  • the access gateway 400 instructs the base station 100 to execute handover to the cell after integration with respect to the handover target mobile station 200 (S117).
  • the determination unit 407 instructs the base station 100 to handover the handover target mobile station 200 to the integrated cell.
  • the determination unit 407 may transmit the antenna configuration corresponding to the integrated cell to the base station 100.
  • the access gateway 400 ends a series of processes (S118).
  • the access gateway 400 detects that the traffic state has not changed from the congestion state to the normal state (No in S112), the access gateway 400 ends the series of processing without performing processing such as cell integration (S118). ).
  • Processing when dividing cells> when the maintenance system 300 or the base station 100 detects a state transition from the normal state to the congestion state based on the traffic information, it determines cell division. The maintenance system 300 or the base station 100 also instructs the mobile station 200 arranged in the new cell to execute handover by dividing the cell.
  • the base station 100 determines the time required for cell division for the mobile station 200 to be handed over to the new cell after division from its own load status.
  • the time required for cell division (hereinafter sometimes referred to as “processing time”) is, for example, the processing time with respect to the usage rate of the CPU (Central Processing Unit) of the base station 100 and the allocation rate of radio resources. Also good. Such a numerical value may be calculated or a predefined value may be used.
  • the base station 100 determines whether the synchronization processing with the handover destination base station is performed by the mobile station (non-contention (non-contention mode)) or the base station (contention (contention mode)). Determine based on.
  • the base station 100 determines to perform synchronization processing led by the base station. This is because, when the processing time takes more than the reference value, if the synchronization processing is led by the mobile station, the mobile station 200 makes many requests for the synchronization processing even though the time required for cell division takes more than the reference value.
  • the power consumption of the mobile station 200 requires more power than the normal value. Therefore, in such a case, by performing synchronization processing led by the base station, the mobile station 200 waits for synchronization processing during cell division processing, and synchronization processing is started by a request from the base station 100 after cell division is completed. Thus, the power consumption of the mobile station 200 can be reduced as compared with the case where the mobile station takes the initiative.
  • the base station 100 determines to perform synchronization processing led by the mobile station. This is because the processing time due to cell division is less than the reference value, and thus the power consumption of the mobile station 200 does not exceed the normal value even if the synchronization processing is performed under the initiative of the mobile station.
  • Whether the synchronization processing is performed by the base station or the mobile station may be performed by the cell control unit 106 of the base station 100, for example.
  • the cell control unit 106 may receive the instruction of the changed antenna configuration from the maintenance system 300 or may determine the antenna configuration by comparing the processing time with the reference value after determining the antenna configuration.
  • FIG. 14 shows an example in which cell # 1 subordinate to base station 100-1 is divided into cell # 1 and cell # 2 by cell division, and two mobile stations 200- In this example, 1,200-2 is arranged.
  • the two mobile stations 200-1 and 200-2 are mobile stations to be handed over from the cell # 1 to the cell # 2.
  • the base station 100-1 acquires the traffic information and transmits the acquired traffic information to the maintenance system (S120). For example, when the base station 100-1 acquires the traffic information, the base station 100-1 periodically transmits the traffic information to the maintenance system 300.
  • the base station 100-1 determines whether or not to divide the cell (S121). Base station 100-1 determines whether or not to divide a cell based on whether or not the state transition from the normal state to the congestion state is performed based on the traffic information.
  • the base station 100-1 determines to divide the subordinate cell (Yes in S121)
  • the base station 100-1 acquires location information from the location information server 500 via the maintenance system 300 or the access gateway 400 (S122).
  • the base station 100-1 analyzes the positional deviation of the mobile station 200 connected to the base station 100-1 based on the acquired location information, and determines the configuration of the cell # 2 (S123). In this case, the base station 100-1 determines that the processing time required for cell division is longer than the reference value, and determines to perform base station-led synchronization processing.
  • the base station 100-1 transmits a handover start instruction to the mobile stations 200-1 and 200-2 arranged in the divided cell # 2 (S124, S125).
  • the first parameter is “Cell Deployment Indicator”.
  • Cell Deployment Indicator is, for example, a parameter indicating whether or not to disable the handover monitoring condition.
  • the “Cell Deployment Indicator” notifies the mobile station 200 of the situation where cell division or cell integration is performed in the base station 100, for example.
  • the mobile station 200 can recognize that cell division or cell integration is performed in parallel in the base station 100 by notifying this parameter, and can invalidate a normal handover completion waiting timer (for example, LTE T304). It becomes.
  • a handover completion waiting timer is, for example, a timer that is instructed by the base station 100 and set on the mobile station 200 side.
  • this parameter for example, an event that causes a handover failure when cell division or cell integration is not completed because a handover completion waiting timer expires can be suppressed.
  • the second parameter is “Wait Time”.
  • “Wait Time” is, for example, a monitoring timer that guarantees the time until cell division processing is completed instead of the invalidated handover completion waiting timer.
  • “Wait Time” indicates, for example, the processing time (or the maximum processing time) required until the base station 100 completes the cell division or cell integration processing and the guaranteed time for executing the synchronization processing with the mobile station 200. Therefore, this parameter is desirably determined by measuring the time required for cell division or cell integration processing under various conditions in system verification by the operator. In addition, this parameter can individually define the maximum processing time for each condition under various conditions (call processing load, CPU usage rate, etc.), and the maximum processing time under all assumed conditions. Can also be defined.
  • the handover completion waiting timer (T304) in LTE has a setting range of “100 ms, 200 ms, 500 ms, 1000 ms, 2000 ms, 4000 ms, and 8000 ms” in 3GPP, and is waiting for a maximum of 8 seconds.
  • This parameter avoids completing the cell division or integration process in the base station 100 within this period due to handover restrictions, and indicates a longer processing time by indicating the processing time depending on the base station 100 with “Wait Time”. (For example, 1s to 3600s) can be specified.
  • the time indicated by “Wait Time” may be longer than the time set as the time until the mobile station 200 starts the handover process and ends it.
  • “Wait Time” is used as a substitute for the handover completion waiting timer invalidated by “Cell Deployment Indicator”, and handover processing according to cell division or cell integration processing depending on base station 100 Is possible.
  • the third parameter is “Sync Mode”.
  • the mobile station 200 side fails in the synchronization establishment process in the commonly used contention mode (driven by the mobile station). Thus, retransmission is repeated while increasing the transmission power. Therefore, in this case, the power consumption of the mobile station 200 may be a problem.
  • the base station 100 uses the “Wait Time” as a reference when the time required for cell division or cell integration is shorter than the reference value, and when it is longer than the reference value, it is used as the non-contention mode (base station initiative).
  • the burden on the mobile station 200 can be reduced.
  • synchronization establishment processing in non-contention mode is desirable, but the length of time required for cell division or cell integration processing and the base station 100 side instructs synchronization establishment processing It is desirable to appropriately define “Sync Mode” in consideration of the processing burden to be performed.
  • the mobile station 200 invalidates the normally used handover completion waiting timer, and is indicated by “Wait Time”. I will wait for a long time.
  • a synchronization establishment instruction request is transmitted from the base station 100 to the mobile station 200. Therefore, the maximum transmission delay in the radio section until the base station-initiated synchronization establishment instruction request arrives at the mobile station 200 during the maximum processing time for cell division or cell integration (hereinafter sometimes referred to as “maximum processing time”).
  • Time or “time lag”, hereinafter “maximum transmission delay time” taking into account the time (for example, “maximum processing time” + “maximum transmission delay time”) may be set as “Wait Time”.
  • a time considering the number of retransmissions and the retransmission interval of the synchronization establishment instruction request (for example, “maximum processing time” + “maximum transmission delay time” ⁇ “retransmission number” + “retransmission interval” ⁇ “retransmission number ⁇ 1”) May be “Wait Time”.
  • a base station-initiated synchronization establishment instruction request may be transmitted from the base station 100 when the timer in the mobile station 200 reaches the maximum processing time. Even in such a case, in order to avoid the risk that the mobile station 200 cannot perform the synchronization process, the maximum transmission delay time is considered for “Wait Time”. After the “Wait Time” period expires, the mobile station 200 waits for a synchronization establishment processing request from the base station 100, and starts the synchronization processing when receiving the request.
  • Sync Mode contention mode
  • the timer in the mobile station 200 reaches the maximum processing time
  • a synchronization establishment instruction request transmitted from the mobile station 200 Can receive.
  • the timer reaches the maximum processing time there is a possibility that the synchronization processing is not in time. Therefore, in the case of the competitive mode, a time that allows one or more retransmissions is added as a margin to the maximum processing time, and the time after the addition may be “Wait Time”.
  • the margin can be calculated from, for example, the number of retransmissions (maximum value preambleTransMax parameter in LTE) and the retransmission interval (maximum value specified in Backoff Parameter in LTE).
  • the base station 100 or the like by setting the number of retransmissions to the maximum value for one retransmission interval, it is possible to guarantee at least one retransmission in the mobile station 200 even when the maximum time is required for antenna reconfiguration.
  • an operator or the like may specify the number of retransmissions to be guaranteed within the range of the number of retransmissions.
  • the mobile station 200 it is possible to give the mobile station 200 a handover condition that is suitable for cell division processing depending on the base station 100, and to implement it. Further, the normal handover waiting timer is invalidated by the three parameters, and the division processing time is guaranteed, and a situation in which handover to the cell after division cannot be performed due to timeout can be avoided. Therefore, in the mobile station 200, handover to the cell after the division that occurs due to the cell division is guaranteed, and it is possible to ensure continuity of communication even when the cell division is performed.
  • these three parameters may be generated when, for example, the cell control unit 106 generates a handover start instruction (S124, S125). That is, the cell control unit 106 generates a handover start instruction, generates three parameters, and outputs them to the control signal processing unit 105.
  • the control signal processing unit 105 generates a control signal including a handover start instruction and three parameters, and transmits the control signal to the mobile stations 200-1 and 200-2 via the transmission power control unit 111 and the like.
  • the control signal is transmitted to the mobile stations 200-1 and 200-2 as, for example, a handover start instruction (S124, S125).
  • band a band
  • frequency a frequency
  • base station 100-1 After transmitting the handover start instruction, base station 100-1 executes cell division (S126). After the processing time has elapsed, cell # 2 is divided, and base station 100-1 accommodating cell # 2 establishes synchronization. A processing request is transmitted to the two mobile stations 200-1 and 200-2 (S127, S131 in FIG. 15). In accordance with the request, the mobile stations 200-1 and 200-2 perform synchronization processing with the base station 100-1 accommodating the cell # 2 (S128, S129, S132 and S133 in FIG. 15), and after the synchronization is established, the handover is completed. A notification is transmitted to the base station 100-1 (S130, S134 of FIG. 15).
  • the base station 100-1 does not perform cell division (No in S121), the base station 100-1 ends the series of processing without performing cell division processing or the like.
  • FIG. 16 is a sequence example illustrating an operation example when cell division fails in the base station 100-1 in the same situation as FIG. 14 and FIG. Each process illustrated in FIG. 16 is performed by, for example, the cell control unit 106, the handover control unit 206, the determination unit 307, and the like.
  • the base station 100-1 performs the cell division process (S126), if the cell division process is not completed even after the processing time elapses, the cell division fails (S141).
  • the mobile stations 200-1 and 200-2 wait for the time indicated by “Wait Time” in response to the handover start instruction (S124, S125), and receive a synchronization establishment processing request from the base station 100 during that time. Wait. However, the mobile stations 200-1 and 200-2 do not receive the synchronization establishment processing request from the base station 100-1 even after the time indicated by “Wait Time” has elapsed. As a result, the mobile stations 200-1 and 200-2 can detect that the cell division process has failed.
  • the mobile stations 200-1 and 200-2 avoid the reconnection process that is performed when a normal handover fails, and roll back to the original cell (S142). As a result, for example, the mobile stations 200-1 and 200-2 can connect to the original cell without performing transmission / reception of a control signal or the like by reconnection processing, ensuring continuity of communication, It is possible to reduce the power consumption of 200-1 and 200-2.
  • FIG. 16 illustrates an example in which the mobile station 200-1 performs rollback to the original cell, but the mobile station 200-2 may perform rollback.
  • the mobile station 200 determines that the base station (or A handover or reconnection procedure may be executed for the cell) (S143).
  • FIG. 17 and FIG. 18 are diagrams showing a sequence example in such a case. The processes shown in FIGS. 17 and 18 are performed by, for example, the cell control unit 106, the handover control unit 206, the determination unit 307, and the like.
  • the base station 100-1 determines that the processing time required for cell division is equal to or less than the reference value.
  • the base station 100-1 determines that the synchronization processing is performed by the mobile station (contention mode) (S123).
  • base station 100-1 performs cell division (S126), and mobile stations 200-1 and 200-2 transmit a synchronization establishment instruction request to a new cell (cell # 2) and wait for a response to the request. (S152, S153).
  • the mobile stations 200-1 and 200-2 repeat the request transmission and standby for the period specified by “Wait Time”.
  • mobile station 200-1 When cell division is executed in base station 100-1, mobile station 200-1 receives a response to synchronization establishment instruction request (S154) from base station 100-1 (S155), and accommodates cell # 2. Synchronization processing is performed with the base station 100-1. When the mobile station 200-1 establishes synchronization with the base station 100-1, the mobile station 200-1 transmits a handover completion notification to the base station 100-1 (S156). Similar processing is performed in the mobile station 200-2 (S157 to S159 in FIG. 18).
  • FIG. 19 shows a sequence example when cell division fails. Each process illustrated in FIG. 19 is performed by, for example, the cell control unit 106, the handover control unit 206, the determination unit 307, and the like.
  • the cell division process is executed in the base station 100-1 (S126), if the cell division process is not completed even after the processing time has elapsed, the cell division has failed (S141).
  • the mobile stations 200-1 and 200-2 transmit a synchronization establishment instruction request to the base station 100-1 that accommodates the cell # 2 (S161 to S163).
  • the base station 100-1 cannot receive the synchronization establishment instruction request.
  • the mobile stations 200-1 and 200-2 do not receive a response to the synchronization establishment instruction request even when the period specified by “Wait Time” expires, so that the base station 100-1 does not perform cell division. It becomes possible to detect failure.
  • the original cell (cell # 1) remains in the cell arrangement after the division.
  • rollback to the original cell is performed (S142).
  • the mobile stations 200-1 and 200-2 can avoid the reconnection procedure performed when a normal handover fails, and can connect to the original cell without transmitting / receiving control signals and the like by the reconnection process, thereby enabling communication continuity. And the power consumption of the mobile stations 200-1 and 200-2 can be reduced.
  • the mobile stations 200-1 and 200-2 detect the reception strength of the cell under the control of the adjacent base station 100-2 at the highest level, the mobile stations 200-1 and 200-2 perform a handover or reconnection procedure to the base station 100-2. It is good (S143).
  • base station 100-1 that performs cell division notifies configuration change notification to neighboring base station 100-2.
  • the configuration change notification includes, for example, three parameters “Cell Deployment Indicator”, “Wait Time”, and “Sync Mode”.
  • the adjacent base station 100-2 can grasp that the cell division is performed in the base station 100-1, and a normal handover completion waiting timer (for example, T RELOCprep in LTE in the case of performing handover to a new cell ).
  • TX2 RELO Coverall can be invalidated. Therefore, the mobile station 200 can perform handover from the adjacent base station 100-2 to the new cell.
  • the mobile station 200 can avoid a situation in which the normal handover completion waiting timer expires and cannot be handed over to a new cell, thereby ensuring continuity of communication.
  • FIGS. 20 and 21 are diagrams showing a sequence example when the mobile station 200 is handed over from the adjacent base station 100-2 to the new cell. Each process illustrated in FIGS. 20 and 21 is performed by, for example, the cell control unit 106, the handover control unit 206, the determination unit 307, and the like.
  • the base station 100-1 determines whether there is a cell adjacent to the cell # 2 (S170). For example, the cell control unit 106 of the base station 100-1 assigns the cell # 2 under the base station 100-1 to the cell # 2 under the base station 100-1 based on the location information of the base stations 100-1 and 100-2 stored in the internal memory. You may determine the presence or absence of an adjacent cell.
  • the base station 100-1 determines that there is a cell adjacent to the cell # 2 (Yes in S170), the base station 100-1 transmits a configuration change notification to the adjacent cell (the adjacent base station 100-2 in the example of FIG. 20) ( S171).
  • the cell control unit 106 determines that there is a cell adjacent to the cell # 2
  • the cell control unit 106 generates a configuration change notification including three parameters, and transmits the generated configuration change notification to the adjacent base via the TCP / IP transmission / reception unit 110. Transmit to station 100-2.
  • the TCP / IP transmission / reception unit 110 of the adjacent base station 100-2 receives a configuration change notification from the base station 100-1, for example, it extracts three parameters included in the notification and outputs them to the cell control unit 106. To do.
  • the adjacent base station 100-2 monitors the elapsed time from when the configuration change is received until the time indicated by “Wait Time”.
  • the mobile station 200-1 transmits a Measurement Report (S174), and the adjacent base station 100-2 transmits a handover start instruction including three parameters to the mobile station 200-1 (S175 in FIG. 21).
  • the handover start instruction includes the cell ID of the new cell # 2 after the division.
  • the adjacent base station 100-2 transmits a handover request to the base station 100-1 (or cell # 1) (S176).
  • the base station 100-1 approves the handover request and grants the handover request approval to the adjacent base station. Transmit to 100-2 (S177).
  • the neighboring base station 100-2 When the neighboring base station 100-2 receives the handover request approval from the base station 100-1, the neighboring base station 100-2 omits the three parameters and performs a normal handover (S178). For example, the adjacent base station 100-2 monitors the elapsed time from when the configuration change notification is received to the time indicated by “Wait Time”. The adjacent base station 100-2 compares the remaining time up to the time indicated by “Wait Time” with the handover completion waiting timer that is normally used, and if the remaining time is longer than the handover completion waiting timer, The remaining time is used as a monitoring timer. However, the adjacent base station 100-2 uses the handover completion waiting timer as a monitoring timer when the handover completion waiting timer becomes longer than the remaining time.
  • the adjacent base station 100-2 compares the remaining time with the handover completion waiting timer and uses the longer one as the monitoring timer. Thereby, for example, the handover time of the mobile station 200-1 to the new cell # 2 is guaranteed, and the continuity of communication can be ensured.
  • the adjacent base station 100-2 uses the handover completion waiting timer as a monitoring timer.
  • Three parameters are omitted (S178).
  • the cell control unit 106 of the adjacent base station 100-2 may perform the handover completion waiting timer stored in the internal memory or the like and the remaining time of “Wait Time”.
  • the determination timing may be, for example, between S175 and S177.
  • the adjacent base station 100-2 receives the Measurement Report from the mobile station 200-2 (S179), and transmits a handover start instruction to the new cell # 2 (S180).
  • the adjacent base station 100-2 transmits normal parameters such as the cell ID of the cell # 2 to the mobile station 200-2 without transmitting the above three new parameters.
  • the adjacent base station 100-2 transmits a handover request for the mobile station 200-2 to the base station 100-1 (S181), and receives a handover request approval from the base station 100-1.
  • the mobile stations 200-1 and 200-2 perform synchronization establishment processing for the new cell # 2 (S183 to S186).
  • the mobile station 200-1 performs a synchronization process in a mode (non-contention mode or contention mode) indicated by “Sync Mode”.
  • processing during cell integration As described above, when the maintenance system 300 or the base station 100 detects a state transition from the congestion state to the normal state based on the traffic information, the maintenance system 300 or the base station 100 determines cell integration. The maintenance system 300 or the base station 100 also instructs the mobile station 200 located in the cell that disappears due to cell integration to execute handover.
  • the base station 100 determines the processing time required for cell integration, similarly to the processing at the time of cell division, and performs synchronization processing between the integrated base station 100 and the mobile station 200 based on the processing time. It is decided whether to carry out by the mobile station or by the mobile station. For example, when the processing time required for cell division is equal to or greater than a reference value, the base station 100 determines to perform synchronization processing led by the base station. On the other hand, for example, when the processing time required for cell division is less than the reference value, the base station 100 determines to perform synchronization processing led by the mobile station.
  • an example of a handover sequence including synchronization processing is divided into a case where synchronization processing is performed under the initiative of the base station (non-contention mode) and a case where synchronization processing is performed under the initiative of the mobile station (contention mode). explain.
  • FIG. 22 illustrates an example of a handover sequence when synchronization processing is performed in the non-contention mode (base station initiative) during cell integration.
  • FIG. 22 shows an example in which the cell integration decision is made by the base station 100.
  • Each process illustrated in FIG. 22 is performed by, for example, the cell control unit 106, the handover control unit 206, the determination unit 307, and the like.
  • FIG. 22 shows an example in which two cells # 1 and # 2 in the base station 100-1 are integrated into one cell # 1 by cell integration, and the mobile stations 200-1 and 200-2 are connected to the cell # 2. However, cell # 2 disappears due to cell integration and handover to cell # 1 is performed.
  • the base station 100-1 determines whether or not to integrate cells based on the traffic information (S190), and determines to integrate cells (Yes in S190). At this time, the base station 100-1 determines that the processing time required for cell integration is longer than the reference value, and also determines to perform synchronization processing led by the base station (non-contention mode). Then, the base station 100-1 acquires the location information of the mobile stations 200-1 and 200-2 from the location information server 500 via the maintenance system 300 or the access gateway 400 (S122), and executes cell integration (S191). ).
  • base station 100-1 When cell # 2 is integrated into cell # 1 in base station 100-1, base station 100-1 that accommodates integrated cell # 1 transmits a synchronization establishment instruction request to mobile stations 200-1 and 200-2. (S195, S199). Then, the base station 100-1 performs synchronization establishment processing led by the base station with the mobile stations 200-1 and 200-2 (S196, S197, S200, S201). When the mobile stations 200-1 and 200-2 establish synchronization with the base station 100-1, they transmit a handover completion notification to the base station 100-1 (S198, S202).
  • the mobile station 200-1 or 200-1 does not receive the synchronization establishment instruction request, so that the cell integration process has failed in the base station 100-1. Can be detected.
  • the original cell before integration (cell # 2 in the example of FIG. 22) remains, so the mobile stations 200-1 and 200-2 roll back to the original cell. It becomes possible.
  • the mobile stations 200-1 and 200-2 when detecting the reception strength of the cell under the control of the adjacent base station 100-2 at the highest level, move to the base station 100-2. A handover or reconnection procedure may be performed.
  • FIG. 23 shows a sequence example in such a case. Each process illustrated in FIG. 23 is performed by, for example, the cell control unit 106, the handover control unit 206, the determination unit 307, and the like.
  • the mobile stations 200-1 and 200-2 After receiving the handover start instruction (S192, S193), the mobile stations 200-1 and 200-2 repeatedly transmit a synchronization establishment instruction request and wait for a response to the request during the period indicated by “Wait Time” ( S210, S211).
  • the synchronization establishment instruction request transmitted from the mobile stations 200-1 and 200-2 is received by the base station 100-1 (S196, S200), and the base station 100-1 To the mobile stations 200-1 and 200-2 (S197, S201).
  • synchronization processing is performed between the mobile stations 200-1 and 200-2 and the base station 100-1 that accommodates the cell # 1, and when synchronization is established, the mobile stations 200-1 and 200-2 perform handover.
  • a completion notification is transmitted to the base station 100-1 (S198, S202).
  • the mobile stations 200-1 and 200-2 fail to perform the cell integration process on the base station 100-1 side by not receiving a response (S197, S201) to the synchronization establishment instruction request after the “Wait Time” period expires. Can be detected. Also in this case, since the original cells before integration remain, the mobile stations 200-1 and 200-2 can roll back to the original cells. However, when the mobile stations 200-1 and 200-2 detect the reception strength of the cell under the control of the adjacent base station 100-2 at the highest level, the mobile stations 200-1 and 200-2 are able to ) Or a reconnection procedure may be performed.
  • base station 100-1 that performs cell integration notifies configuration change notification to adjacent base station 100-2.
  • the configuration change notification includes three parameters “Cell Deployment Indicator”, “Wait Time”, and “Sync Mode”.
  • the adjacent base station 100-2 grasps that the cell integration is executed in the base station 100-1, and the normal handover is performed when the handover to the new cell after the integration under the base station 100-1 is executed. It is possible to invalidate completion waiting timers (eg, T RELOCprep and TX2 RELOC Coverall in LTE). Therefore, the mobile station 200 can perform handover from the adjacent base station 100-2 to the new cell after integration, and can ensure continuity of communication.
  • FIGS. 24 and 25 show sequence examples when handover is performed from the adjacent base station 100-2 to the new cell (cell # 1) to be integrated with the cell. Each process illustrated in FIGS. 24 and 25 is performed by, for example, the cell control unit 106, the handover control unit 206, the determination unit 307, and the like.
  • the base station 100-1 After acquiring the location information, the base station 100-1 determines whether there is a cell adjacent to the cell # 2 that disappears due to cell integration (S220). If there is a cell adjacent to cell # 2 (“There is an adjacent cell” in S220), base station 100-1 transmits a configuration change notification to adjacent base station 100-2 (S221). On the other hand, when there is no cell adjacent to cell # 2 (“No adjacent cell” in S220), base station 100-1 performs cell integration without transmitting a configuration change notification (S191).
  • the base station 100-1 invalidates the normal handover completion waiting timer (for example, LTE T RELOCprep and TX2 RELOC Coverall ), substitutes the time indicated by “Wait Time”, and indicates “Sync Mode”.
  • the synchronization process is performed according to the mode to be used.
  • the adjacent base station 100-2 uses the remaining time as a monitoring timer while the remaining time of “Wait Time” is longer than the normal handover completion waiting timer.
  • the adjacent base station 100-2 uses the normal handover completion waiting timer as a monitoring timer when the normal handover completion waiting timer becomes longer than the remaining time.
  • the adjacent base station 100-2 uses a normal handover completion waiting timer as a monitoring timer. Therefore, the adjacent base station 100-2 performs normal handover (S227 to S229 in FIG. 25).
  • the base station 100-1 performs synchronization processing with the mobile station 200-1 in the mode specified by “Sync Mode”, and is normally in competition mode with the mobile station 200-2. Are synchronized (S332 to S335).
  • FIG. 26 shows a configuration example of the mobile communication system 10.
  • the mobile communication system 10 includes an eNB (evolved Node B) 100, UEs (User Equipment) 200-1 to 200-3, EMS / NMS 300, and E-SMLC (Evolved Serving Mobile Location Center) 560.
  • the eNB 100 is the base stations 100-1 and 100-2
  • the mobile stations 200-1 and 200-2 are UEs 200-1 to 200-3
  • the location information server 500 is Each corresponds to E-SMLC560.
  • UE 200-1 is represented as a UE that could not acquire location information.
  • the operation example of the cell division and integration determination sequence will be described separately for a case where it is led by eNB (for example, FIG. 27) and a case where it is led by EMS / NMS (for example, FIG. 28).
  • MME Mobility Management Entity
  • FIG. 30 operation examples of a cell division processing sequence (for example, FIG. 32), a cell integration processing sequence (for example, FIG. 34), and a handover from a neighboring eNB (for example, FIGS. 36 and 37) will be described.
  • an operation example when cell division and integration processing failure has failed for example, FIG. 38) will be described.
  • UEs 200-1 to 200-3 may be described as the UE 200 unless otherwise specified.
  • FIG. 27 illustrates a sequence example in the case of determining cell division and integration led by an eNB. Each process illustrated in FIG. 27 is performed by, for example, the cell control unit 106, the handover control unit 206, the determination units 307 and 407, and the like.
  • the eNB 100 confirms the traffic load of each of the UEs 200-1 to 200-3 as needed, and the traffic load (or traffic information. Hereinafter, it may be referred to as “traffic load”) and a threshold (for example, a congestion state threshold and a normal state) (Threshold) are compared (S350).
  • the eNB 100 confirms a change in the relationship between the traffic load and the threshold (S351), and performs the processing from S352 onward when the traffic load exceeds the threshold, and performs the processing in S361 when the traffic load falls below the threshold.
  • the eNB 100 When the traffic load is equal to or greater than the threshold, the eNB 100 requests location information of all UEs 200 connected to the eNB 100 from the EMS / NMS 300 (S352). In this case, the eNB 100 may include identification information of all UEs 200 connected to the eNB 100 in the acquisition request.
  • the location information acquisition request is transmitted to the E-SMLC 560 via the EMS / NMS 300 (S353), and the E-SMLC 560 returns the location information to the EMS / NMS 300 (S354).
  • the EMS / NMS 300 When the EMS / NMS 300 receives location information from the E-SMLC 560 (S354), the EMS / NMS 300 checks whether the location information of all UEs 200 is included in the location information received from the E-SMLC 560, and the location information of all UEs 200 exists. Then, the process proceeds to S355. On the other hand, when the location information received from the E-SMLC 560 does not include the location information of all UEs 200, the EMS / NMS 300 proceeds to the process of S356.
  • the determination unit 307 of the EMS / NMS 300 determines that the location information of all UEs 200 is included if the identification information of all UEs received from the eNB 100 is included in the location information acquired from the E-SMLC 560. On the other hand, when the identification information of all UEs 200 is not included in the position information acquired from E-SMLC 560, determination unit 307 determines that the position information of all UEs 200 is not included.
  • the EMS / NMS 300 When the location information of all UEs 200 exists, the EMS / NMS 300 returns the location information of all UEs 200 received from the E-SMLC 560 to the eNB 100 (S355).
  • the EMS / NMS 300 returns the location information received from the E-SMLC 560 to the eNB 100, and the radio quality information used for the three-point survey for the UE 200-1 without the location information. Is transmitted to the eNB 100 (S356).
  • the eNB 100 receives the measurement instruction, transmits a radio quality measurement and transmission instruction to the UE 200-1 (S357), and the UE 200-1 transmits a Measurement Report to the eNB 100 (S358).
  • the eNB 100 transmits the instruction by the cell control unit 106, and the UE 200-1 measures the radio quality by the handover control unit 206.
  • the eNB 100 receives the Measurement Report and determines the location information of the UE 200-1 by the three-point survey method (S359).
  • the location information may be determined by the cell control unit 106 (or the mobile station location information management unit 109).
  • the eNB 100 When the eNB 100 receives the location information of all the UEs 200 in S355 or acquires the location information of all the UEs 200 in S355 and S359, the eNB 100 calculates the antenna configuration by cell division based on the location information of all the UEs 200 (S360). ). And in eNB100, UE200 used as the object made to hand over to the new cell after a division is determined (S362).
  • the handover target UE 200 is, for example, a UE that is connected to different cells before and after cell division.
  • the eNB 100 calculates an antenna configuration by cell integration (S361), and determines a handover target UE 200 (S362).
  • the handover target UE 200 is, for example, a UE that is connected to different cells before and after cell integration.
  • FIG. 28 shows a sequence example in the case of determining cell division and cell integration led by EMS / NMS. Each process shown in FIG. 28 is performed by, for example, the cell control unit 106, the handover control unit 206, the determination units 307 and 407, and the like.
  • the EMS / NMS 300 confirms the traffic load of the eNB 100 as needed (S370, S371), compares the traffic load with a threshold (for example, a congestion state threshold and a normal state threshold) (S372), and if the relationship changes,
  • the UE information of the currently connected UE 200 is acquired from the eNB 100 (S373, S374).
  • the UE information includes identification information of the UE 200.
  • the EMS / NMS 300 performs cell division by the processing after S353 when the traffic load changes to a threshold value or more. On the other hand, when the traffic load changes below the threshold, the EMS / NMS 300 performs cell integration by the process of S382.
  • the EMS / NMS 300 requests the location information of all UEs 200 from the E-SMLC 560, and the E-SMLC 560 returns the location information of the existing (held) UEs 200 (S354).
  • the EMS / NMS 300 when the location information of all UEs 200 acquired from the eNB 100 does not exist in the location information acquired from the E-SMLC 560, transmits to the eNB 100 a radio quality acquisition instruction based on three-point surveying (S375). In response to the acquisition instruction, the eNB 100 acquires the radio quality information of the UE 200-1 having no position information (S376, S377), and transmits the acquired position information to the EMS / NMS 300 (S378).
  • the EMS / NMS 300 determines the position information of the UE 200-1 by the three-point survey method (S380). For example, the mobile station location information management unit 306 (or determination unit 307) of the EMS / NMS 300 may determine the location information based on the three points of radio quality information acquired from the eNB 100.
  • the EMS / NMS 300 analyzes the bias based on the location information of all the UEs 200, and calculates the antenna configuration by cell division (S381).
  • the EMS / NMS 300 determines a handover target UE 200 (S383), transmits information on the antenna configuration and the handover target UE 200 to the eNB 100, and instructs the eNB 100 of the antenna configuration and the handover target UE 200 (S384).
  • the EMS / NMS 300 calculates an antenna configuration based on cell integration (S382), determines a handover target UE 200 (S383), and instructs the eNB 100 about the antenna configuration and the UE 200. (S384).
  • FIG. 29 is a diagram illustrating a configuration example of the mobile communication system 10 including the MME 450.
  • the mobile communication system 10 further includes an MME 450 and an E-SMLC (Evolved Serving Mobile Location Center) 560.
  • the MME 450 corresponds to the access gateway 400 and the E-SMLC 560 of the mobile communication system 10 shown in FIG.
  • FIG. 30 shows a sequence example in the case of performing cell division and cell integration determination led by MME450. Each process illustrated in FIG. 30 is performed by, for example, the cell control unit 106, the handover control unit 206, the determination units 307 and 407, and the like.
  • the eNB 100 checks the traffic load of the local station as needed, and compares a threshold (for example, a congestion state threshold and a normal state threshold) with the traffic load (S350). And eNB100 will transmit a traffic state change notification to MME450, if the state transition to a load state (or congestion state) or a normal state (or relaxation state) is detected (S390).
  • a threshold for example, a congestion state threshold and a normal state threshold
  • the MME 450 determines cell division or cell integration according to the content of the state change. That is, when the MME 450 detects a state change to the congestion state, the MME 450 determines cell division and requests the E-SMLC 560 for location information of all UEs 200 located in the eNB 100 (S391). In this case, since the MME 450 holds information on all the UEs 200 connected to the eNB 100, the MME 450 does not transmit an acquisition request for the location information of the UE 200 to the eNB 100.
  • the MME 450 instructs the eNB 100 to acquire the radio quality information of the UE 200-1 for which location information does not exist (S393).
  • the eNB 100 acquires radio quality from the UE 200-1 according to the acquisition instruction (S394, S395), and transmits it to the MME 450 (S396).
  • the MME 450 When the MME 450 receives the radio quality information from the eNB 100 (S394 to S396), the MME 450 determines the position of the UE 200-1 using the three-point surveying method for the radio quality information. Then, the MME 450 analyzes the UE bias based on the location information of all the UEs 200, and determines an antenna configuration that maximizes the cell capacity by cell division (S397).
  • the MME 450 determines the UE 200 to be handed over by cell division (S399) and notifies the eNB 100 (S400).
  • the MME 450 determines cell integration and calculates an antenna configuration (S398), determines a UE 200 that needs to move after cell integration (S399), and notifies the eNB 100 (S400). .
  • FIG. 31 illustrates a configuration example of the mobile communication system 10.
  • the example of FIG. 31 represents an example in which the cell ID of the cell in which the UE 200 is located is changed from “Cell # 1” to “Cell # 2” due to cell division.
  • FIG. 32 shows a sequence example of cell division processing. Each process illustrated in FIG. 32 is performed by, for example, the cell control unit 106 and the handover control unit 206.
  • ENB100 transmits RRC Connection Reconfiguration with respect to UE200 connected to a new cell (S410).
  • the RRC Connection Reconfiguration indicates that, for example, the eNB 100 instructs the UE 200 to establish an RRC connection and connect to a new cell.
  • the RRC Connection Reconfiguration includes three parameters: “Cell Deployment Indicator”, “Wait Time”, and “Sync Mode”.
  • the RRC Connection Reconfiguration includes “New Cell ID” (or “New C-ID”), “Band”, and “Frequency” as other parameters.
  • the UE 200 Upon receiving the RRC Connection Reconfiguration, the UE 200 waits for a synchronization process with the cell (“Cell # 2”) specified by the “New Cell ID”. That is, the UE 200 waits for the reception of RA Preamble Assignment from the eNB 100 that accommodates Cell # 2 for a period specified by “Wait Time” (S412).
  • the eNB 100 After transmitting the RRC Connection Reconfiguration, the eNB 100 performs cell division by beam forming or the like for each antenna 101 (S411). The eNB 100 transmits the RA Preamble Assignment to the UE 200 connected to the new cell (“Cell # 2”) (S413).
  • the UE 200 that has received the RA Preamble Assignment transmits the RA Preamble instructed by the RA Preamble Assignment to the eNB 100 (S414).
  • the eNB 100 that has received the RA Preamble transmits an RA Response to the UE 200 (S415).
  • the RA response includes, for example, a timing adjustment value.
  • the UE 200 that has received the RA Response transmits the RRC Connection Reconfiguration Complete to the eNB 100 based on the determination that the RRC Connection Reconfiguration processing has been completed (S416).
  • FIG. 33 shows a configuration example of the mobile communication system 10.
  • FIG. 33 illustrates an example in which “Cell # 2” disappears due to cell integration, and UE 200 located in “Cell # 2” hands over to “Cell # 1”.
  • FIG. 34 shows a sequence example of cell integration processing. Each process illustrated in FIG. 34 is performed by, for example, the cell control unit 106 and the handover control unit 206.
  • ENB 100 transmits RRC Connection Reconfiguration to UE 200 connected to “Cell # 2” (S420).
  • the UE 200 that has received the RRC Connection Reconfiguration transmits an RA Preamble to the cell (“Cell # 1”) specified by the “New Cell ID”, and waits for the reception of the RA Response (S422, S423). The UE 200 repeats this transmission and standby for the period specified by “Wait Time”.
  • ENB100 performs cell integration by beam forming etc. after transmitting RRC Connection Reconfiguration (S421). After cell integration, the eNB 100 receives the RA preamble transmitted from the UE 200 (S424), and transmits an RA response to the UE 200 (S425).
  • the UE 200 that has received the RA Response transmits the RRC Connection Reconfiguration Complete to the eNB 100 based on the determination that the RRC Connection Reconfiguration processing has been completed (S426).
  • FIG. 35 shows a configuration example of the mobile communication system 10.
  • the cell ID is changed from “Cell # 1” to “Cell # 2” by cell division in the eNB 100-1.
  • FIG. 35 illustrates an example in which two UEs 200-1 and 200-2 are handed over from the neighboring eNB 100-2 to “Cell # 2.”
  • FIG. 36 shows an example of a handover sequence from the neighboring eNB 100-2.
  • Each process illustrated in FIG. 36 is performed by, for example, the neighboring eNB 100-2, the cell control unit 106 of the eNB 100-1 that performs cell division, the handover control unit 206, or the like.
  • the eNB 100-1 investigates neighboring neighboring eNBs when performing cell division, and discriminates the neighboring cells from the new cell after cell division. Then, the eNB 100-1 transmits the eNB Configuration Update to the adjacent eNB 100-2 that accommodates the cell adjacent to the new cell (S430).
  • eNB Configuration Update corresponds to, for example, the above-described configuration change notification (for example, S171 in FIG. 20).
  • the eNB Configuration Update includes two parameters, “Cell Deployment Indicator” and “Wait Time”. “Sync Mode” may be determined by the neighboring eNB 100-2, and “Sync Mode” may or may not be included in the eNB Configuration Update.
  • the adjacent eNB 100-2 When the adjacent eNB 100-2 receives the eNB Configuration Update, the adjacent eNB 100-2 starts a timer (or count) for the time specified by “Wait Time” (S431).
  • the UE 200-1 connected to the adjacent eNB 100-2 becomes a handover target ( S432).
  • the adjacent eNB 100-2 uses the timer specified by “Wait Time” as the monitoring timer.
  • the adjacent eNB 100-2 transmits a Handover Request to the eNB 100-1 that is performing the cell division process (S433).
  • the eNB 100-1 When the eNB 100-1 receives the Handover Request, the eNB 100-1 transmits a Handover Request Acknowledgment to the adjacent eNB 100-2 (S434).
  • the neighboring eNB 100-2 When the neighboring eNB 100-2 receives the Handover Request Acknowledgment, the neighboring eNB 100-2 transmits an RRC Connection Reconfiguration to the UE 200-1 (S435).
  • the RRC Connection Reconfiguration includes three new parameters: “Cell Deployment Indicator”, “Wait Time”, and “Sync Mode”. Among these, “Cell Deployment Indicator” and “Wait Time” may be included in the eNB Configuration Update (S430), and “Sync Mode” may be determined by the neighboring eNB 100-2. Alternatively, all the three new parameters included in the eNB Configuration Update (S430) may be used as they are in the adjacent eNB 100-2.
  • the UE 200-1 Upon receiving the RRC Connection Reconfiguration, the UE 200-1 waits for the reception of the RA Preamble Assignment for the period specified by “Wait Time” (S436).
  • the UE 200-1 After cell division (S441), upon receiving the RA Preamble Assignment (S442), the UE 200-1 performs a synchronization process (S442 to S445).
  • the neighboring eNB 100-2 assumes that the UE 200-2 connected to the neighboring eNB 100-2 becomes a handover target (S437). In this case, the neighboring eNB 100-2 uses the handover completion waiting timers T RELOCprep and TX2 RELO Coverall having a remaining time longer than “Wait Time” as monitoring timers. At this time, the neighboring eNB 100-2 transmits a Handover Request to the eNB 100-1 that is performing the cell division process (S438).
  • the neighboring eNB 100-2 When the neighboring eNB 100-2 receives the Handover Request Acknowledgment from the eNB 100-1 (S439), the neighboring eNB 100-2 transmits an RRC Connection Reconfiguration to the UE 200-1 (S440).
  • the UE 200-2 When receiving the RRC Connection Reconfiguration, the UE 200-2 waits for the reception of the RA Preamble Assignment during the handover completion waiting timer T304.
  • the UE 200-1 receives the RA Preamble Assignment (S450 in FIG. 37), and performs synchronization processing (S451 to S453).
  • FIG. 38 shows a sequence example in the case where handover is not completed when the cell division process fails. Each process shown in FIG. 38 is performed by the cell control unit 106 and the handover control unit 206, for example.
  • ENB 100-1 transmits RRC Connection Reconfiguration to UE 200-1 connected to the new cell (“Cell # 2”) (S460).
  • the UE 200-1 Upon receiving the RRC Connection Reconfiguration, the UE 200-1 waits for the synchronization process for the period indicated by “Wait Time” (S461).
  • the eNB 100-1 that performs the cell division processing cannot transmit the RA Preamble Assignment in the “Wait Time” due to a processing load or the like.
  • the period indicated by “Wait Time” expires without receiving the RA Preamble Assignment during the “Wait Time” period (S462).
  • the UE 200-1 detects that the cell division has failed in the eNB 100-1 by not receiving the RA Preamble Assignment during the “Wait Time” period. In this case, the UE 200-1 resumes (or rolls back) communication with the eNB 100-1 connected immediately before. The UE 200-1 resumes communication with the eNB 100 without performing a normal reconnection procedure. The eNB 100-1 suspends the communication process with the UE 200-1, and responds to the connection resumption from the UE 200-1 (S463).
  • the UE 200-1 can return to the communication with the eNB 100-1 accommodating “Cell # 1” without performing the reconnection procedure after the “Wait Time” period expires.
  • the base station 100 (or cell) can divide or integrate the frequency (or carrier) f1 used into two frequencies f1 and f2. is there.
  • the mobile station 200 may perform a handover due to a change in frequency.
  • the maintenance system 300 acquires traffic information from the base station 100, acquires position information from the position information server 500, and configures the antenna configuration based on the traffic information and position information. The change from the first configuration to the second configuration may be determined.
  • the base station 100 transmits three parameters (“Cell Deployment Indicator”, “Wait Time”, and “Sync Mode”) to the mobile station 200 to be handed over.
  • the “frequency” may be used instead of the “cell” described in the second embodiment, and the mobile communication system 10 can implement what has been described in the second embodiment. Therefore, it is possible to appropriately control the cell capacity and ensure continuity of communication.
  • the configuration of the antenna it is possible to divide or integrate the communication method into the first method and the second method in one base station 100 (or cell).
  • Communication methods include LTE and 5G.
  • the mobile station 200 may perform handover by changing the communication method. Even in this case, the mobile communication system 10 can be replaced with the “communication method” instead of the “cell” described in the second embodiment. Then, what has been described in the second embodiment can be implemented.
  • the mobile communication system 10 performs the second implementation. It becomes possible to carry out what has been described in the form.
  • Non-Patent Document 4 includes, for example, a pattern that allows different antennas for transmission and reception. When such a pattern is executed by cell division, the pattern of the second embodiment described above is used. Examples are applicable.
  • FIG 39 is a diagram illustrating a hardware configuration example of the base station 100
  • FIG. 40 is a mobile station 200
  • FIG. 41 is a hardware configuration of the maintenance system 300, the access gateway 400, or the location information server 500.
  • the base station 100 includes an antenna 101, a CPU 150, a ROM (Read Only Memory) 151, a RAM (Random Access Memory) 152, a memory 153, a DSP (Digital Signal Processor) 154, a wireless processing unit 155, An IF (Interface) 156 is provided.
  • the CPU 150 reads out a program stored in the ROM 151, loads it into the RAM 152, and executes the loaded program, whereby the control signal processing unit 105, the cell control unit 106, the antenna control unit 107, the traffic information management unit 108, the mobile station The functions of the position information management unit 109 and the transmission power control unit 111 are executed. Therefore, for example, the CPU 150 is connected to the control signal processing unit 105, the cell control unit 106, the antenna control unit 107, the traffic information management unit 108, the mobile station location information management unit 109, and the transmission power control unit 111 in the second embodiment. Correspond.
  • the DSP 154 executes functions of the reception multiple access processing unit 103, the demodulation / decoding unit 104, the encoding / modulation unit 112, and the transmission multiple access processing unit 113 in accordance with an instruction from the CPU 150. Therefore, the DSP 154 corresponds to, for example, the reception multiple access processing unit 103, the demodulation / decoding unit 104, the encoding / modulation unit 112, and the transmission multiple access processing unit 113 in the second embodiment.
  • the memory 153 corresponds to, for example, the traffic information management unit 108 and the mobile station location information management unit 109 in the second embodiment.
  • the wireless processing unit 155 corresponds to the reception wireless unit 102 and the transmission wireless unit 114.
  • the IF 156 corresponds to, for example, the TCP / IP transmission / reception unit 110 in the second embodiment.
  • the base station 100 includes two CPUs 150, one corresponding to the control signal processing unit 105, the cell control unit 106, the traffic information management unit 108, the mobile station location information management unit 109, and the transmission power control unit 111.
  • the other one may correspond to the antenna control unit 107.
  • the mobile station 200 includes an antenna 201, a CPU 250, a ROM 251, a RAM 252, a memory 253, a DSP 254, and a wireless processing unit 255.
  • the CPU 250 reads out the program stored in the ROM 251 and loads it into the RAM 252 and executes the loaded program, whereby the control signal extraction unit 205, the handover control unit 206, the synchronization processing unit 207, the rollback control unit 208, the control signal The functions of the processing unit 209 and the transmission power control unit 210 are executed.
  • the CPU 250 corresponds to, for example, the control signal extraction unit 205, the handover control unit 206, the synchronization processing unit 207, the rollback control unit 208, the control signal processing unit 209, and the transmission power control unit 210 in the second embodiment.
  • the DSP 254 corresponds to, for example, the reception multiple access processing unit 203, the demodulation / decoding unit 204, the encoding / modulation unit 211, and the transmission multiple access processing unit 212 in the second embodiment.
  • the wireless processing unit 255 corresponds to, for example, the reception wireless unit 202 and the transmission wireless unit 213 in the second embodiment.
  • the maintenance system 300 includes a CPU 350, a ROM 351, a RAM 352, a memory 353, and an IF 354.
  • the CPU 350 reads out the program stored in the ROM 351, loads it into the RAM 352, and executes the loaded program, whereby the signal analysis units 302 and 305, the traffic information management unit 303, the mobile station location information management unit 306, and the determination unit 307. Realize the function.
  • the CPU 350 corresponds to, for example, the signal analysis units 302 and 305, the traffic information management unit 303, the mobile station location information management unit 306, and the determination unit 307 in the second embodiment.
  • the memory 353 corresponds to, for example, the traffic information management unit 303 and the mobile station location information management unit 306 in the second embodiment.
  • the IF 354 corresponds to, for example, the TCP / IP transmission / reception unit 301 for the base station and the TCP / IP transmission / reception unit 304 for the location information server in the second embodiment.
  • the access gateway 400 includes a CPU 460, a ROM 461, a RAM 462, a memory 463, and an IF 464.
  • the CPU 460 reads out the program stored in the ROM 461, loads it into the RAM 462, and executes the loaded program, whereby the signal analysis units 402 and 405, the traffic information management unit 403, the mobile station location information management unit 406, and the determination unit 407. Realize the function.
  • the CPU 460 corresponds to, for example, the signal analysis units 402 and 405, the traffic information management unit 403, the mobile station location information management unit 406, and the determination unit 407 in the second embodiment.
  • the memory 463 corresponds to, for example, the traffic information management unit 403 and the mobile station location information management unit 406 in the second embodiment.
  • the IF 464 corresponds to, for example, the TCP / IP transmission / reception unit 401 for base stations and the TCP / IP transmission / reception unit 404 for location information servers in the second embodiment.
  • the location information server 500 includes a CPU 510, a ROM 511, a RAM 512, a memory 513, and an IF 514.
  • the position information of the mobile station 200 is stored in the memory 513 via the IF 514 under the control of the CPU 510.
  • the CPU 510 appropriately reads the position information of the mobile station 200 stored in the memory 513 and transmits it to the maintenance system 300 via the IF 514.
  • Mobile communication system 100 (100-1, 100-2): Base station apparatus (eNB) 101: Antenna 102: Reception radio unit 105: Control signal processing unit 106: Cell division / integration control unit 107: Antenna control unit 108: Traffic information management unit 109: Mobile station location information management unit 110: TCP / IP transmission / reception unit 114: Transmission radio unit 120: AAS 121: BBU 125-1, 125-2, ...: Transceiver units 126-1, 126-2, ...: Antenna (or antenna element) 200 (200-1, 200-2): Mobile station apparatus 206: Handover control unit 207 for cell division / integration: Synchronization processing unit 208: Rollback control unit 250: CPU 300: Maintenance system (EMS / NMS) 303: Traffic information management unit 306: Mobile station location information management unit 307: Cell division / integration (antenna configuration) determination unit / mobile station determination unit 350: CPU 400: Access gateway 403: Traffic information management unit 406: Mobile station location information Management unit 406

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Abstract

La présente invention concerne un appareil de communications, pouvant être connecté à un serveur d'informations de position qui gère des informations de position concernant un appareil de station mobile, et comportant: une unité d'émission/réception qui reçoit, en provenance de l'appareil de station mobile, des informations de trafic concernant un trafic entre un appareil de station de base et l'appareil de station mobile, et reçoit les informations de position de l'appareil de station mobile en provenance du serveur d'informations de position; et une unité de détermination qui détermine un changement de la configuration d'une antenne d'une première configuration à une deuxième configuration au niveau de l'appareil de station de base d'après les informations de trafic et les informations de position, et envoie une instruction de passage à la deuxième configuration à l'appareil de station de base via l'unité d'émission/réception.
PCT/JP2016/050222 2016-01-06 2016-01-06 Appareil de communications, appareil de station de base, système de communications mobiles, procédé de communications, et appareil de station mobile Ceased WO2017119077A1 (fr)

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PCT/JP2016/050222 WO2017119077A1 (fr) 2016-01-06 2016-01-06 Appareil de communications, appareil de station de base, système de communications mobiles, procédé de communications, et appareil de station mobile

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PCT/JP2016/050222 WO2017119077A1 (fr) 2016-01-06 2016-01-06 Appareil de communications, appareil de station de base, système de communications mobiles, procédé de communications, et appareil de station mobile

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