WO2015019406A1 - 基地局装置、移動端末、および、無線通信システム - Google Patents
基地局装置、移動端末、および、無線通信システム Download PDFInfo
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- WO2015019406A1 WO2015019406A1 PCT/JP2013/071184 JP2013071184W WO2015019406A1 WO 2015019406 A1 WO2015019406 A1 WO 2015019406A1 JP 2013071184 W JP2013071184 W JP 2013071184W WO 2015019406 A1 WO2015019406 A1 WO 2015019406A1
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- cell
- mobile terminal
- base station
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- 238000004891 communication Methods 0.000 title claims description 68
- 230000005540 biological transmission Effects 0.000 claims abstract description 63
- 238000012545 processing Methods 0.000 claims description 93
- 238000001514 detection method Methods 0.000 claims description 19
- 238000013459 approach Methods 0.000 claims description 13
- 238000004364 calculation method Methods 0.000 claims description 10
- 238000000034 method Methods 0.000 description 107
- 230000008569 process Effects 0.000 description 44
- 238000010586 diagram Methods 0.000 description 14
- 238000009434 installation Methods 0.000 description 6
- CIWBSHSKHKDKBQ-JLAZNSOCSA-N Ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-JLAZNSOCSA-N 0.000 description 5
- 238000005259 measurement Methods 0.000 description 4
- 230000008859 change Effects 0.000 description 3
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- 238000012546 transfer Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
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Classifications
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- 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
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- 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
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/0005—Control or signalling for completing the hand-off
- H04W36/0083—Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
- H04W36/00835—Determination of neighbour cell lists
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/04—Reselecting a cell layer in multi-layered cells
-
- 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
- H04W16/32—Hierarchical cell structures
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/0005—Control or signalling for completing the hand-off
- H04W36/0055—Transmission or use of information for re-establishing the radio link
- H04W36/0061—Transmission or use of information for re-establishing the radio link of neighbour cell information
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W64/00—Locating users or terminals or network equipment for network management purposes, e.g. mobility management
Definitions
- the present invention relates to communication between a mobile terminal and a base station.
- the “small cell” refers to a cell having a smaller cell radius and the number of simultaneously accessible users compared to a macro cell.
- a small cell may be installed in a macro cell in order to cope with an increase in the number of macro cell users and an increase in the amount of communication per user.
- the small cell is set to communicate using a frequency band different from the frequency band used in the macro cell including the small cell. There are many.
- the mobile terminal specifies a physical cell ID (PCI, physical cell identifier) assigned to the small cell of the handover destination in order to perform handover to the small cell base station.
- PCI physical cell ID
- the mobile terminal performs processing in the frequency band used for communication by the small cell of the handover destination. Therefore, a mobile terminal that wants to acquire information of a handover-destination small cell during communication with a macro cell can use both the frequency band used for communication via the macro cell and the frequency band used for communication in the small cell. Will be processed.
- the power consumption of the mobile terminal increases. Furthermore, since the mobile terminal located at a position away from the small cell repeats the process until the physical cell ID can be acquired, the power consumed for searching for the small cell is further increased.
- the mobile terminal determines whether there is a small cell in the vicinity of the mobile terminal using the fingerprint information.
- the fingerprint information is information that is generated when the small cell is located and is stored in the storage medium of the mobile terminal, and the position related to the small cell such as the location information of the mobile terminal when the small cell is located Contains information.
- the mobile terminal compares the location information in the fingerprint stored in the storage medium with the current location of the mobile terminal to identify the physical cell ID for the small cell determined to be in the vicinity.
- a mobile terminal that stores a list indicating accessible small cells has been devised.
- the mobile terminal receives the network policy from the base station, the mobile terminal determines whether the small cell is accessible from the information regarding the accessible small cells included in the list. At this time, fingerprint information is used as information on accessible small cells.
- the mobile terminal notifies the determination result to the base station (for example, Patent Document 1).
- a method has been proposed in which a base station determines a handover destination of a mobile terminal. In this method, the base station that determines the handover destination reduces the list of base stations that transfer the same physical cell identifier using the fingerprint table, and specifies the handover destination (for example, Patent Document 2).
- the mobile terminal determines that the small cell is in the vicinity using the fingerprint information, the mobile terminal starts searching for the small cell.
- the conventional fingerprint information does not include information on a cell in which the mobile terminal has never been located. For this reason, when the conventional fingerprint method is used, it is difficult for the mobile terminal to efficiently find a small cell in which the mobile terminal has never been located.
- searching for a small cell of a handover destination without using the fingerprint method even if the mobile terminal is located away from the small cell, the search process is performed, so that the search efficiency is poor and the mobile terminal Power consumption will increase. Note that a method for allowing a mobile terminal to efficiently search for a cell set in a frequency band different from the frequency band used for communication has not been obtained for a macro cell.
- An object of the present invention is, as one aspect, to enable a mobile terminal to efficiently find a cell.
- the base station apparatus is capable of wireless communication with a mobile terminal located in the first cell, and includes a storage unit and a transmission unit.
- the storage unit stores position information of a second cell that can be a destination of the mobile terminal.
- the transmission unit transmits the location information of the second cell to the mobile terminal, and causes the mobile terminal to detect approach to the second cell using the location information.
- the mobile terminal can efficiently find the cell.
- FIG. 1 is a diagram illustrating an example of communication between a base station and a mobile terminal.
- the base station 10x forms a cell X.
- the cell X may be a macro cell or a small cell.
- the cell X is a macro cell.
- a cell smaller than a macro cell is referred to as a “small cell”.
- the small cell can be a micro cell, a pico cell, a femto cell, or the like.
- the base station 10a is a small cell A base station
- the base station 10b is a small cell B base station
- the base station 10c is a small cell C base station.
- FIG. 1 is a diagram illustrating an example of communication between a base station and a mobile terminal.
- the base station 10x forms a cell X.
- the cell X may be a macro cell or a small cell.
- the cell X is a macro cell.
- a cell smaller than a macro cell is referred to as
- the frequency band used for communication in the small cells A to C is set to a frequency band different from that of the cell X.
- the mobile terminal 5 has communicated with the cell X, but has not accessed any of the small cells A to C, and any location information of the small cells A to C It shall not be held.
- the base station 10x stores cell location information that can be a handover destination of a mobile terminal communicating with the base station 10x.
- a cell that can be a destination of a mobile terminal communicating with the base station 10x is a cell of any size sharing at least one point with the cell X.
- a cell that can be a destination of a mobile terminal communicating with the base station 10x includes a cell included in the cell X, a cell formed in a region including a part of the cell X, and a cell X. Cell is included.
- the cells that can be the destination of the mobile terminal communicating with the base station 10 x are the small cell A, the small cell B, and the small cell C.
- the base stations 10a to 10c are assumed to hold cell location information that can be the destination of a mobile terminal communicating with the base station 10x.
- the mobile terminal 5 is located in the cell X and is communicating with the base station 10x.
- the base station 10 x transmits the location information of the small cell A, the small cell B, and the small cell C to the mobile terminal 5.
- the mobile terminal 5 compares the position information acquired from the cell X with the position of the mobile terminal 5 to detect approach to a cell that can be a destination. For example, it is assumed that the mobile terminal 5 detects the small cell B as a destination candidate. Then, the mobile terminal 5 specifies the physical cell ID of the small cell B after acquiring information used for acquiring the physical cell ID of the small cell from the base station 10x.
- the mobile terminal 5 notifies the physical cell ID of the small cell B to the base station 10 x and moves from the cell X to the small cell B.
- the base station 10 b When communication with the mobile terminal 5 is started, the base station 10 b notifies the mobile terminal 5 of the location information of the cell that can be the destination of the mobile terminal 5. For example, the base station 10b can notify the mobile terminal of the location information of the small cells A and C. The mobile terminal 5 can detect that it has approached the small cell A or the small cell C using the information acquired from the base station 10b. The mobile terminal 5 can appropriately request the handover process from the base station 10b using the physical cell ID assigned to the small cell that has detected the approach.
- the mobile terminal can acquire the location information of the cell that can be the destination from the communicating base station. For this reason, the mobile terminal can efficiently discover even a small cell that has never been in the area by comparing the location information of the mobile terminal itself with the location information acquired from the base station.
- a base station of a small cell may hold information on a base station that can be a destination from a macro cell that shares one or more points with the small cell.
- the small cell A in FIG. Therefore, the base station 10a forming the small cell A can store the location information of the small cells B and C that can be moved to by the mobile terminal communicating using the cell X. Even in this case, since the mobile terminal 5 communicating with the base station 10a can acquire the location information of the small cells B and C from the base station 10a, it is possible to efficiently discover even a small cell that has never been in the area. Can do.
- each of the base stations 10a to 10c, 10x may store the small cell position information in advance, and acquire the small cell position information from a server or the like that can communicate via the network as appropriate. Also good.
- the base station 10 acquires the position information of the small cell from the server will be described as an example.
- FIG. 2 shows an example of the configuration of the mobile terminal 5 and the base stations 10 (10a to 10c).
- the base stations 10 a to 10 c can access the server 30 via the network 1.
- the base station 10 includes a signal processing unit 11, a radio processing unit 12, an update unit 15, a handover processing unit 16, an adjustment unit 17, and a storage unit 20.
- the wireless processing unit 12 includes a reception unit 13 and a transmission unit 14.
- the storage unit 20 holds a position information table 21. The configuration of the base station 10 that forms the macro cell and the configuration of the base station 10 that forms the small cell are the same.
- the signal processing unit 11 processes a signal used in communication via the network 1.
- the receiving unit 13 receives information transmitted from the mobile terminal 5.
- the transmission unit 14 transmits information such as position information to the mobile terminal 5.
- the location information table 21 includes location information of small cells that can be the destination of the mobile terminal 5 communicating with the base station 10.
- the update unit 15 updates the position information table 21 when the position information of the small cell is updated.
- the update unit 15 acquires the location information of the small cell from the server 30 via the signal processing unit 11.
- the handover processing unit 16 is a process for the mobile terminal 5 in communication to start communication with another base station 10 or a process for starting communication with the mobile terminal 5 in communication with another base station 10. I do.
- the adjustment unit 17 generates a message for notifying the mobile terminal 5 of small cell information that can be the destination of the mobile terminal 5.
- the adjustment unit 17 outputs the generated message to the transmission unit 14. Furthermore, the adjustment unit 17 can adjust the timing of transmitting a message including position information. The operation of the adjustment unit 17 will be described later.
- the base station 10 may further include a calculation unit 18.
- the calculation unit 18 can calculate the moving speed of the mobile terminal 5 and output the calculation result to the adjustment unit 17 in association with the identifier of the mobile terminal 5.
- the mobile terminal 5 includes a receiving unit 51, a transmitting unit 52, an updating unit 61, a specifying unit 62, a detecting unit 63, a handover processing unit 64, and a storage unit 70.
- the receiving unit 51 receives information such as position information from the base station 10.
- the transmission unit 52 transmits information to the base station 10.
- the update unit 61 updates the position information table 71 using the position information received from the base station 10.
- the specifying unit 62 specifies the position of the mobile terminal 5.
- the specifying unit 62 can specify the position of the mobile terminal 5 using GPS (Global Positioning System) or the like.
- the detecting unit 63 compares the information obtained by the specifying unit 62 with the position information in the position information table 71 to detect that the small cell that can be the destination is approached.
- the detection unit 63 stores a threshold value Thd in advance. For example, when the distance from the position of the mobile terminal 5 to the base station 10 of the small cell is equal to or less than the threshold value Thd, the detection unit 63 can determine that the small cell has been approached. For example, when the cell radius is included in the position information table 71, the detection unit 63 approaches the small cell when the distance from the position of the mobile terminal 5 to the boundary of the small cell is equal to or less than the threshold Thd. You may determine that you did.
- the detection unit 63 generates a message (notification information) for notifying the handover source base station 10 of the approach to the small cell, and transmits the message via the transmission unit 52.
- the handover processing unit 64 performs processing related to handover.
- the storage unit 70 holds a position information table 71.
- the server 30 includes a reception unit 31, an update unit 32, a search unit 33, a selection unit 34, a transmission unit 35, and a storage unit 40.
- the storage unit 40 holds a macro cell information table 41, a small cell information table 42, a macro cell management table 43, and a small cell management table 44.
- the receiving unit 31 receives macro cell information and small cell information.
- the receiving unit 31 may acquire, from each base station 10, position information of the base station 10 and information on a frequency band used for communication.
- the receiving unit 31 may acquire information on each base station 10 via the network 1 from a device that previously holds information such as the installation position of the base station 10.
- the update unit 32 updates the macro cell information table 41 and the small cell information table 42 using the information acquired via the reception unit 31.
- the macro cell information table 41 holds information such as the position of the base station forming the macro cell and the frequency band used for communication in the macro cell.
- the small cell information table 42 holds information such as the position of the base station forming the small cell and the frequency band used for communication in the small cell. Examples of the macro cell information table 41 and the small cell information table 42 will be described later.
- the search unit 33 updates the macro cell management table 43 and the small cell management table 44 using the updated macro cell information table 41 and the small cell information table 42.
- the search unit 33 searches for a small cell that can be a destination of the mobile terminal 5 for each macro cell, using information such as the position of the macro cell, the cell radius of the macro cell, the position of the small cell, and the cell radius of the small cell.
- the search unit 33 records the obtained result in the macro cell management table 43 in association with the physical cell ID of the macro cell.
- the search unit 33 searches for a small cell that may be the destination of movement by the mobile terminal 5 that is communicating with the small cell.
- the search unit 33 records the search result for each small cell in the small cell management table 44 in association with the physical cell ID of the small cell.
- An example of the macro cell management table 43 and the small cell management table 44 and a specific example of processing of the search unit 33 will be described later.
- the selection unit 34 generates destination cell information for notifying the base station 10 of location information.
- the “destination cell information” includes location information of a cell that can be a destination for the mobile terminal 5 communicating with the destination base station 10 of the destination cell information.
- the selection unit 34 selects information to be transmitted according to the transmission destination base station 10. For example, when the information transmission destination is the base station 10 of the macro cell, the selection unit 34 uses the macro cell management table 43 to select a small cell associated with the identifier of the macro cell formed by the base station 10 of the transmission destination. To select. On the other hand, when the small cell base station 10 is the transmission destination, the selection unit 34 uses the small cell management table 44 to select the small cell associated with the identifier of the transmission destination base station 10.
- the selection unit 34 acquires information on the selected small cell from the small cell information table 42 and generates destination cell information to be transmitted to the base station 10.
- the selection unit 34 outputs the movement destination cell information to the transmission unit 35 together with information for identifying the transmission destination base station 10.
- the transmission unit 35 transmits the destination cell information to the base station 10.
- FIG. 3 shows an example of the hardware configuration of the base station 10.
- the base station 10 includes an antenna 101, an amplifier 102, a baseband processing circuit 103, a processor 104, a memory 105, and a transmission path interface 106.
- the base station 10 communicates with the mobile terminal 5 via the antenna 101.
- the antenna 101 and the amplifier 102 operate as the wireless processing unit 12.
- the baseband processing circuit 103 processes a baseband signal.
- the processor 104 can be any processing circuit including Central Processing Unit (CPU).
- the processor 104 operates as the update unit 15, the handover processing unit 16, the adjustment unit 17, and the calculation unit 18 by executing a program stored in the memory 105.
- the memory 105 operates as the storage unit 20 and stores data, programs, and the like used for processing of the base station 10 as appropriate.
- the transmission path interface 106 implements the signal processing unit 11.
- the base station 10 performs communication with the network 1 via the transmission path interface 106 and communication via the interoffice line.
- FIG. 4 shows an example of the hardware configuration of the mobile terminal 5.
- the mobile terminal 5 includes an antenna 111, an amplifier 112, a baseband processing circuit 113, a processor 114, and a memory 115.
- the mobile terminal 5 communicates with the base station 10 via the antenna 111.
- the antenna 111 and the amplifier 112 operate as the reception unit 51 and the transmission unit 52.
- the baseband processing circuit 113 processes the baseband signal.
- the processor 114 is an arbitrary processing circuit including a CPU.
- the processor 114 operates as the updating unit 61, the specifying unit 62, the detecting unit 63, and the handover processing unit 64 by executing a program stored in the memory 115.
- the memory 115 operates as the storage unit 70 and stores data, programs, and the like used for processing of the mobile terminal 5 as appropriate.
- FIG. 5 shows an example of the hardware configuration of the server 30.
- the server 30 includes a processor 121, a memory 122, a bus 125, an external storage device 126, and a network connection device 129.
- the server 30 may further include an input device 123, an output device 124, and a medium driving device 127.
- the processor 121 is an arbitrary processing circuit including a CPU.
- the processor 121 operates as the update unit 32, the search unit 33, and the selection unit 34.
- the processor 121 can execute a program stored in the external storage device 126, for example.
- the memory 122 operates as the storage unit 40. Furthermore, the memory 122 also appropriately stores data obtained by the operation of the processor 121 and data used for the processing of the processor 121.
- the network connection device 129 is used for communication with other devices, and operates as the reception unit 31 and the transmission unit 35.
- the input device 123 is realized as, for example, a button, a keyboard, or a mouse
- the output device 124 is realized as a display or the like.
- the bus 125 connects the processor 121, the memory 122, the input device 123, the output device 124, the external storage device 126, the medium drive device 127, and the network connection device 129 so that data can be exchanged between them.
- the external storage device 126 stores programs, data, and the like, and provides the stored information to the processor 121 as appropriate.
- the medium driving device 127 can output data in the memory 122 and the external storage device 126 to the portable storage medium 128, and can read programs, data, and the like from the portable storage medium 128.
- the portable storage medium 128 may be any portable storage medium including a floppy disk, a Magneto-Optical (MO) disk, a Compact-Disc-Recordable (CD-R) and a Digital-Versatile-Disk-Recordable (DVD-R). It can be a medium.
- a floppy disk a Magneto-Optical (MO) disk
- CD-R Compact-Disc-Recordable
- DVD-R Digital-Versatile-Disk-Recordable
- FIG. 6 shows an example of the arrangement of macro cells and small cells.
- the identifier of the macro cell is represented by a character string in which uppercase letters of three letters are continuous
- the identifier of the small cell is represented by a character string in which lowercase letters of three letters are consecutive.
- cell AAA and cell BBB in FIG. 6 are macro cells
- cells aaa and bbb are small cells.
- the physical cell ID and the identifier of each cell are represented by the same character string.
- the physical cell ID of the cell AAA is AAA.
- FIG. 6 shows an example of the arrangement of macro cells and small cells.
- the macro cell AAA includes a small cell aaa and a small cell bbb, and shares a part of the area with the small cell ccc. Furthermore, since the macro cell AAA is in contact with the small cell ddd and the small cell ee, it can be said that the small cell ddd and the small cell ee share at least one point.
- the macro cell BBB includes a small cell ddd and a small cell fff, and further shares a partial area with the small cell bbb.
- the communication method according to the first embodiment will be described by taking as an example the case where the macro cell and the small cell are arranged as shown in FIG.
- the following is divided into a method of identifying a cell that can be the destination of the mobile terminal 5, notification of location information to the base station 10, notification of location information from the base station 10 to the mobile terminal 5, and processing at the mobile terminal 5 explain.
- FIG. 7 shows an example of the macro cell information table 41 and the small cell information table 42.
- both the macro cell information table 41 and the small cell information table 42 are associated with the physical cell ID assigned to each cell, and are used for the installation position and communication of the base station that forms the cell.
- the frequency band and cell radius are recorded.
- the position information is a combination of latitude and longitude, and the value with xx at the end is latitude (north latitude) and the value with yy at the end is longitude (east longitude)
- the macro cell AAA and the macro cell BBB use the same frequency band.
- each of the small cells aaa to fff uses a frequency band different from that of the macro cell AAA or the macro cell BBB for communication. Furthermore, between small cells, the frequency band used for communication may be the same or different. In the example of FIG. 7, both the macro cell AAA and the macro cell BBB communicate in the 2.2 GHz band.
- the small cells aaa, ccc, ddd, and eee use a frequency band of 800 MHz, while the small cells bbb and fff use a frequency band of 900 MHz.
- FIG. 8 is a flowchart for explaining an example of processing of the updating unit 32.
- the macro cell information table 41 and the small cell information table 42 are updated by the procedure shown in FIG.
- the receiving unit 31 of the server 30 associates the location information of the base station 10 and information such as the cell radius with the physical cell ID from the device or the base station 10 that holds information such as the location of the base station 10. get.
- the receiving unit 31 outputs the acquired information to the updating unit 32 (step S1).
- the update unit 32 specifies whether the information input from the reception unit 31 is information of a macro cell or a small cell.
- the method by which the update unit 32 specifies the cell size is arbitrary.
- the update unit 32 may store a physical cell ID assigned to the macro cell in advance.
- the updating unit 32 may specify whether the input information is a macro cell or a small cell using, for example, a cell radius or transmission power value. If the update unit 32 determines that the input information is macro cell information, the update unit 32 searches the macro cell information table 41 using the physical cell ID associated with the notified information as a key (step S2).
- the updating unit 32 creates a new entry in the macro cell information table 41 and registers the input information in the macro cell information table 41 (step S2). No, step S3).
- the updating unit 32 determines that there is a difference between the information recorded in the macro cell information table 41 and the information input from the receiving unit 31. It is determined whether or not there is (Yes in Step S2, Step S4). When it is determined that there is a difference between the two, the updating unit 32 updates the macro cell information table 41 using the information notified from the receiving unit 31 (Yes in Step S4, Step S5).
- step S1 if there is no difference between the information associated with the physical cell ID as a key and the information in the macro cell information table 41 and the information input from the receiving unit 31, the updating unit 32 ends the process (step S1). No in S4, step S6).
- step S6 By performing the processing described with reference to FIG. 8, when the macro cell is arranged as shown in FIG. 6, the macro cell information table 41 shown in FIG. 7 is obtained.
- the update unit 32 performs the same processing as the processing described with reference to FIG. 8 on the information input from the receiving unit 31 as well as the information determined to be small cell information.
- the small cell information table 42 shown in FIG. 7 is obtained.
- the macro cell information table 41 and / or the small cell information table 42 are changed in the cell installation status by the process shown in FIG. Will be updated accordingly.
- FIG. 9 is a flowchart for explaining an example of a method for updating the macro cell management table 43.
- FIG. 10 is an example of the macro cell management table 43.
- the search unit 33 searches for a small cell that can be the destination of the mobile terminal 5 for each macro cell, and records the obtained result in the macro cell management table 43. To do.
- a small cell that can be a destination of the mobile terminal 5 may be referred to as an “assigned small cell”.
- the allocated small cell is a small cell allocated to each base station 10 as a target for notifying the mobile terminal 5 in communication of location information.
- the order of step S11 and step S12 can be changed according to the implementation.
- the search unit 33 acquires the number of entries (M) included in the macro cell information table 41 and the number of entries (N) included in the small cell information table 42 (step S11).
- the constant M is the total number of macro cells
- the constant N is the total number of small cells.
- the search part 33 sets the variable m and the variable n to 1 (step S12, S13). Note that m is a variable that identifies an entry in the macro cell information table 41, and n is a variable that identifies an entry in the small cell information table 42.
- the search unit 33 acquires the macro cell information recorded in the m-th entry from the macro cell information table 41 and records it in the macro cell management table 43 (step S14).
- a physical cell ID, position information, a frequency band, and a cell radius are recorded in each entry.
- R be the cell radius of the mth macro cell.
- the search unit 33 acquires the following information about the cell AAA from the first entry of the macro cell information table 41 shown in FIG. Physical cell ID: AAA Position information: North latitude 35.730541 degrees, East longitude 139.77124 degrees Frequency band: 2.2 GHz Cell radius: 500m
- the search unit 33 generates the macro cell management table 43a shown in FIG. 10 using the acquired information.
- the search unit 33 acquires the position information and the cell radius of the small cell recorded in the nth entry from the small cell information table 42 (step S15).
- the cell radius of the nth small cell is assumed to be r.
- the search unit 33 calculates the distance (D) between the mth macro cell and the nth small cell using the position information of the mth macrocell and the position information of the nth small cell (step S16).
- the calculation of the distance by the search unit 33 can be an arbitrary calculation method using information on the latitude and longitude of two points.
- the distance D calculated in the example of FIG. 9 is the distance between the base station of the mth macro cell and the base station of the nth small cell.
- the search unit 33 compares the distance D with the total value of the cell radius of the mth macro cell and the cell radius of the nth small cell (step S17). When the distance D is less than or equal to the total value, the mth macro cell and the nth small cell share at least one point. For example, when the distance D is equal to the total value, the mth macro cell and the nth small cell are in contact with each other. When the distance D is smaller than the total value, there is an area where the mth macro cell and the nth small cell overlap.
- the search unit 33 determines that the nth small cell can be a destination from the mth macrocell, and records it in the macrocell management table 43 (Yes in step S17). Step S18). For example, as shown in FIG. 6, the distance between the macro cell AAA and the small cell aaa is smaller than the sum of the cell radius of the macro cell AAA and the cell radius of the small cell aaa. Then, the search unit 33 updates the macro cell management table 43a to the macro cell management table 43b (FIG. 10) with the small cell aaa as the allocated small cell of the macro cell AAA.
- the search unit 33 determines that the nth small cell cannot be a destination from the mth macrocell, and does not record it in the macrocell management table 43 (No in step S17). Step S19).
- step S18 or step S19 the search unit 33 increments the variable n by 1, and then compares the variable n with the total number N of small cells (steps S20 and S21).
- step S15 the processes after step S15 are repeated (No in step S21). That is, it is determined whether each small cell can be a destination cell for the macro cell specified by the variable m.
- the search unit 33 increments the variable m by 1, and then compares the variable m with the total number M of macro cells (steps S22 and S23).
- the variables m is equal to or less than the total number M of macro cells, the processes after step S13 are repeated (No in step S23). Therefore, the data in the macro cell management table 43 is updated for all macro cells.
- the search unit 33 ends the process (Yes in step S23). For this reason, when cells are arranged as shown in FIG. 6, the macro cell management table 43c (FIG. 10) is obtained by the processing described with reference to FIG.
- FIG. 11 is a flowchart for explaining an example of a method for updating the small cell management table 44.
- FIG. 12 is an example of the small cell management table 44.
- the search unit 33 searches for a small cell that can be the destination of the mobile terminal 5 for each small cell, and records the obtained result in the small cell management table 44.
- FIG. 12 an example of processing of the search unit 33 when generating the small cell management table 44 illustrated in FIG. 12 will be described with reference to FIG.
- the order of step S31 and step S32 can be changed with each other according to the implementation.
- the search unit 33 acquires the number of macro cell entries (M) included in the macro cell management table 43 and the number of entries (N) included in the small cell information table 42 (step S31).
- the constant M is the total number of macro cells
- the constant N is the total number of small cells.
- the search part 33 sets the variable p and the variable q to 1 (step S32, S33).
- p is a variable that identifies a small cell
- q is a variable that identifies a macro cell.
- the search unit 33 acquires information on the small cell recorded in the p-th entry from the small cell information table 42 and records it in the small cell management table 44 (step S34). For example, the search unit 33 records the physical cell ID, position information, frequency band, and cell radius of the small cell in the small cell management table 44.
- the search unit 33 refers to the entry of the qth macro cell in the macro cell management table 43, and determines whether or not the allocated small cell includes the pth small cell (step S35).
- the p-th small cell is included, information on small cells other than the p-th small cell among the assigned small cells of the q-th macro cell is set as the allocated small cell of the p-th small cell (step) Yes in S35, step S36).
- the search unit 33 specifies the allocated small cell of the macro cell AAA using the macro cell management table 43c (FIG. 10).
- the allocated small cells of the macro cell AAA are the cell aaa, the cell bbb, the cell ccc, the cell ddd, and the cell eeee. Since the small cell aaa is included in the allocated small cell of the macro cell AAA, the search unit 33 sets a cell other than the small cell aaa among the allocated small cells of the macro cell AAA as the allocated small cell of the small cell aaa. Accordingly, as shown in the small cell management table 44a (FIG. 12), the search unit 33 records that the allocated small cells of the cell aaa are the cell bbb, the cell ccc, the cell ddd, and the cell eeee.
- the search unit 33 increments the variable q by 1, and then compares the variable q with the total number M of macro cells (steps S37 and S38). If the variable q is less than or equal to the total number M of macrocells, the processes after step S35 are repeated (No in step S38). For this reason, when specifying an allocation small cell about one small cell, the information on the allocation small cell of all the macro cells is used. Therefore, when a certain small cell is an allocated small cell of a plurality of macro cells, the allocated small cell of the small cell is specified using information on the plurality of macro cells. For example, the small cell bbb is an allocated small cell of the macro cell AAA, and is also an allocated small cell of the macro cell BBB.
- the cell aaa, the cell ccc, the cell ddd, and the cell eeee are the allocated small cells of the cell bbb. Furthermore, since the allocated small cells of the macro cell BBB are the cell bbb, the cell ddd, and the cell fff, the cell fff is also an allocated small cell of the cell bbb.
- the search unit 33 increments the variable p by 1, and then compares the variable p with the total number N of small cells (steps S39 and S40).
- the variables p is less than or equal to the total number N of small cells, the processes after step S33 are repeated (No in step S40). For this reason, the data of the small cell management table 44 are updated about all the small cells.
- the search unit 33 ends the process (Yes in step S40). For this reason, when cells are arranged as shown in FIG. 6, the small cell management table 44b shown in FIG. 12 is obtained by the processing described with reference to FIG.
- FIG. 13 is a sequence diagram illustrating an example of a method for identifying a cell that can be a destination of a mobile terminal. This process is executed by the server 30, for example.
- the arrow shown in FIG. 13 shows the example of the flow of information.
- FIG. 13 is an example, and the order of operations can be changed according to the implementation. For example, procedures (3) and (4) may be performed before procedures (1) and (2).
- the receiving unit 31 When receiving the information of the base station 10, the receiving unit 31 outputs the received information to the updating unit 32.
- the updating unit 32 determines whether the information input from the receiving unit 31 is information of the base station 10 of the macro cell or the small cell. Here, it is assumed that information on a macro cell base station is input. Then, the update unit 32 updates the macro cell information table 41.
- the update unit 32 performs the same determination as in the procedure (2). Here, it is assumed that information of a small cell base station is input. Then, the update unit 32 updates the small cell information table 42.
- the storage unit 40 holds the updated macro cell information table 41 and small cell information table 42.
- the search unit 33 accesses the storage unit 40 and acquires information of the macro cell information table 41 and the small cell information table 42.
- the search unit 33 uses the macro cell information table 41 and the small cell information table 42 to specify a small cell that can be a destination from each cell.
- the search unit 33 updates the macro cell management table 43 and the small cell management table 44. At this time, the search unit 33 records a small cell that can be a destination from each cell in the macro cell management table 43 or the small cell management table 44 as an allocated small cell.
- the server 30 notifies the base station 10 of the destination cell information.
- destination cell information includes location information of a cell that can be a destination for the mobile terminal 5 communicating with the destination base station 10 of the destination cell information.
- movement destination cell information it is assumed that arbitrary information including position information of each cell is associated with the physical cell ID of the allocated small cell of the base station 10 serving as the destination.
- the first letter alphabet of the physical cell ID formed by the operating base station 10 is described at the end of the code.
- the base station 10A forms a macro cell AAA
- the base station 10b forms a small cell bbb.
- the location information table 21A is the location information table 21 held in the base station 10A.
- the selection unit 34 identifies an allocated small cell for the base station 10 that is the transmission destination of the movement destination cell information from the macro cell management table 43. Furthermore, the selection unit 34 selects position information about the specified allocated small cell from the small cell management table 44. Note that the selection unit 34 may acquire the position information about the allocated small cell from the small cell information table 42.
- the selection unit 34 when generating the movement destination cell information to be transmitted to the base station 10A of the macro cell AAA, specifies the allocated small cell associated with the cell AAA from the macro cell management table 43c (FIG. 10).
- the allocated small cells associated with the cell AAA are the cell aaa, the cell bbb, the cell ccc, the cell ddd, and the cell eeee.
- the selection unit 34 obtains location information and the like for each identified cell from the small cell management table 44, thereby generating destination cell information.
- FIG. 14 shows an example of the movement destination cell information transmitted to the base station 10A of the macro cell AAA.
- the destination cell information is generated by the same process.
- the selection unit 34 specifies an allocated small cell for the base station 10 that is the transmission destination of the movement destination cell information from the small cell management table 44. Further, the selection unit 34 also selects position information about the specified allocated small cell from the entries in the small cell management table 44. Note that the selection unit 34 may also obtain location information about the allocated small cell from the small cell information table 42 when generating the destination cell information addressed to the base station 10 of the small cell.
- the selection unit 34 when generating destination cell information to be transmitted to the base station 10d of the macro cell ddd, specifies an allocated small cell associated with the cell ddd from the small cell management table 44b (FIG. 12). .
- the allocated small cells associated with the cell ddd are cell aaa, cell bbb, cell ccc, cell eeee, and cell fff.
- the selection unit 34 obtains location information and the like for each identified cell from the small cell management table 44, thereby generating destination cell information.
- the selection unit 34 also generates destination cell information for the base stations 10 of other small cells by the same process.
- FIG. 15 is a sequence diagram illustrating an example of a process of notifying the base station 10 of the movement destination cell information.
- FIG. 15 illustrates an example of communication processing when the server 30 notifies the destination cell information to the base station 10A forming the macro cell AAA. However, between the server 30 and the base station 10 of another macro cell, The same applies to communication in
- the selection unit 34 acquires information on the macro cell management table 43 and the small cell management table 44 from the storage unit 40.
- the selection unit 34 searches the macro cell management table 43 using the physical cell ID of the cell formed by the transmission destination base station 10A as a key.
- the physical cell ID of the cell formed by the base station 10A is AAA.
- the selection unit 34 generates destination cell information addressed to the base station 10A. The method of generating the destination cell information is as described with reference to FIG.
- the selection unit 34 outputs the generated destination cell information to the transmission unit 35 by designating the base station 10A as a destination.
- the transmission unit 35 transmits the destination cell information input from the selection unit 34 to the base station 10A.
- the signal processing unit 11A of the base station 10A receives a signal from the server 30.
- the signal processing unit 11A acquires the destination cell information from the received signal and outputs it to the update unit 15A.
- the updating unit 15A compares the destination cell information with the position information table 21A. If there is a difference between the location information table 21A and the destination cell information, the updating unit 15A updates the location information table 21A according to the destination cell information. At this time, the updating unit 15A may update only the information about the base station that has a difference between the location information table 21A and the destination cell information. Further, the information in the location information table 21A that is already held may be deleted, and the information included in the destination cell information may be used as the location information table 21A.
- FIG. 16 shows an example of the location information table 21A when the destination cell information shown in FIG. 14 is transmitted to the base station 10A.
- the update unit 15A outputs the updated position information table 21A to the storage unit 20A.
- the storage unit 20A holds the updated position information table 21A.
- the server 30 generates and notifies the destination cell information by the same method. For this reason, when the server 30 holds the macro cell management table 43c (FIG. 10) and the small cell management table 44b (FIG. 12), the base station 10B holds the position information table 21B shown in FIG.
- the process performed when notifying the destination cell information to the small cell base station 10 is also the same.
- the macro cell management table 43 is not used when generating the destination cell information to be transmitted to the base station 10 of the small cell, the selection unit 34 does not access the macro cell management table 43 in the procedure (11).
- the server 30 holds the small cell management table 44b (FIG. 12)
- the base station 10a holds the position information table 21a of FIG.
- the base station 10b holds the position information table 21b of FIG.
- FIG. 17 is a sequence diagram illustrating an example of processing performed when the base station 10 notifies the mobile terminal 5 of position information.
- the handover processing unit 16 of the base station 10 performs a process for handover of the mobile terminal 5.
- the entry of the mobile terminal 5 into the cell of the base station 10 is referred to as “hand-in”.
- the handover processing unit 16 detects hand-in when communication with the mobile terminal 5 is started.
- the base station 10 can use transmission / reception of an arbitrary message performed after the synchronization process between the mobile terminal 5 and the handover destination base station 10 for hand-in detection. A specific example of the hand-in detection method will be described later.
- the handover processing unit 16 Upon detecting the hand-in, the handover processing unit 16 notifies the adjustment unit 17 of the occurrence of the hand-in.
- the adjustment unit 17 obtains position information by accessing the position information table 21 in the storage unit 20.
- the adjustment unit 17 generates a message to be transmitted to the mobile terminal 5 using the acquired position information.
- the adjustment unit 17 can use, as position information, a list in which physical cell IDs and position information are associated with each other for all small cells included in the position information table 21.
- the adjustment unit 17 can also include information on the cell radius and frequency of each small cell in the message addressed to the mobile terminal 5 together with the position information.
- the adjustment unit 17 outputs the generated message to the transmission unit 14.
- the transmission unit 14 transmits the message input from the adjustment unit 17 to the mobile terminal 5.
- the mobile terminal 5 updates the location information table 71 using the message received from the base station 10. Processing in the mobile terminal 5 will be described later.
- FIG. 18 is a sequence diagram illustrating an example of handover. An example of a hand-in detection method will be described with reference to FIG. FIG. 18 shows an example of processing performed when the mobile terminal 5 is handed over from the base station 10B to the base station 10A.
- the handover destination base station 10A receives a request message for requesting the start of communication using the macro cell AAA formed by the base station 10A from the mobile terminal 5, a hand to the macro cell AAA is received. Detect in.
- the mobile terminal 5 When the mobile terminal 5 receives the Measurement Control from the communicating base station 10B, the mobile terminal 5 measures the received intensity from the surrounding base stations (procedure (31)). The mobile terminal 5 reports the obtained result to the base station 10B using Measurement Report (procedure (32)). The base station 10B determines that the mobile terminal 5 is handed over from the base station 10B to the base station 10A using the Measurement Report, and transmits a Handover Request to the handover destination base station 10A (procedure (33)). The handover destination base station 10A, after performing the process associated with the reception of the Handover Request, transmits a Handover Request ACK to the base station 10B (procedure (34)).
- the base station 10B requests the mobile terminal 5 for a handover by transmitting the RRC Connection Reconfiguration to the mobile terminal 5 (procedure (35)). Furthermore, the base station 10B notifies the sequence number of the packet to be transmitted next to the mobile terminal 5 by sending the SN Status Transfer to the base station 10A (procedure (36)). Thereafter, synchronization processing is performed between the base station 10A and the mobile terminal 5 (procedure (37)).
- RRC Connection Reconfiguration Complete is an example of a request message. That is, when the process of the procedure (37) fails and the mobile terminal 5 cannot hand-in to the macrocell AAA, the mobile terminal 5 does not transmit the RRC Connection Reconfiguration Complete. For this reason, when the handover processing unit 16A of the base station 10A receives the RRC Connection Reconfiguration Complete, it determines that the hand-in has been detected.
- the handover processing unit 16A notifies the adjustment unit 17A of the hand-in, and the adjustment unit 17A uses the position information to transmit to the mobile terminal 5 according to the procedure described with reference to FIG. Is generated.
- This message may include, for example, information recorded in the position information table 21A shown in FIG.
- the base station 10A notifies the location information by transmitting the generated message to the mobile terminal 5 (procedure (39)).
- the base station 10A requests path switching by transmitting a Path Switch Request to the Mobility Management Entity (MME) (procedure (40)).
- MME Mobility Management Entity
- the MME notifies the Serving Gateway (SGW) that the mobile terminal 5 communicates with the base station 10A by transmitting the User Plane Update Request (procedure (41)).
- SGW Serving Gateway
- the MME transmits a Path Switch Request ACK to the base station 10A (procedures (42) and (43)).
- the base station 10A transmits a UE Context Release to the base station 10B (procedure (44)).
- FIG. 18 is an example of a hand-in detection method, and the hand-in detection method may be changed depending on the implementation.
- the processing after the procedure (38) is not performed when the mobile terminal 5 cannot be handed over. Therefore, for example, the handover processing unit 16 of the handover destination base station 10 may be modified so as to detect hand-in when transmitting a message in the procedure (40) or the procedure (44). Similarly, the handover processing unit 16 may be modified so as to detect a hand-in when receiving a Path Switch Request ACK from the MME.
- the base station 10 transmits a message including position information to the mobile terminal 5 after detecting the hand-in.
- the position information table 71a in FIG. 19 is an example of the position information table 71 held by the mobile terminal 5 when processing for performing hand-in to the macro cell AAA is started.
- the mobile terminal 5 starts a handover to the base station 10A
- the mobile terminal 5 holds the position information of small cells that can move from the cell BBB formed by the base station 10B.
- the position information table 71a holds the information of the cell bbb, the cell ddd, and the cell fff, similarly to the position information table 21B of FIG.
- the base station 10A generates a message including the position information with reference to the position information table 21A (FIG. 19), and transmits the message to the mobile terminal 5.
- the receiving unit 51 of the mobile terminal 5 outputs the message to the updating unit 61.
- the update unit 61 determines whether the position information included in the message received from the base station 10 is the same information as the position information table 71a. When there is a difference between the position information included in the message received from the base station 10 and the information in the position information table 71a, the update unit 61 deletes the information recorded in the position information table 71.
- the updating unit 61 records the position information input from the receiving unit 51 in the position information table 71.
- the update unit 61 updates the position information table 71a to the position information table 71b using the information input from the base station 10A.
- the update unit 61 not only adds the newly notified small cell information, but is not notified from the base station. Small cell information has been deleted. For this reason, the mobile terminal 5 can erase the information of the small cells that can no longer be the destination after the handover among the small cells that could be the destination before the handover.
- FIG. 20 is a flowchart for explaining an example of the update process of the position information table 71.
- the receiving unit 51 receives a message including position information from the base station 10 (step S51).
- the receiving unit 51 outputs the message to the updating unit 61.
- the update unit 61 determines whether the position information notified from the base station 10 using the message matches the contents of the position information table 71 (step S52).
- the update unit 61 updates the contents of the position information table 71 so as to match the received position information (inconsistency in step S52, step S53).
- the updating unit 61 ends the process without updating the position information table 71 (matching in step S52, step S54).
- FIG. 21 is a sequence diagram illustrating an example of handover using a location information table.
- FIG. 21 shows an example of processing when the mobile terminal 5 is handed in to the macro cell AAA, then moves in the macro cell AAA, and is handed over to the base station 10c due to the proximity of the small cell ccc.
- the mobile terminal 5 uses the position information table 71b (FIG. 19).
- the specifying unit 62 specifies the current position of the mobile terminal 5.
- the specifying unit 62 includes, for example, GPS, and obtains the latitude and longitude of the position of the mobile terminal 5 using GPS data.
- the identification unit 62 outputs the latitude and longitude values of the position of the mobile terminal 5 to the detection unit 63.
- the detection unit 63 calculates the distance between the position of the base station 10 and the position of the mobile terminal 5 of each cell recorded in the position information table 71 using the values of latitude and longitude. It is assumed that the distance between the mobile terminal 5 and the base station 10c becomes equal to or less than the threshold due to the movement of the mobile terminal 5.
- the detection unit 63 notifies the base station 10A that has established communication that it has approached the small cell ccc by transmitting notification information.
- the notification information can be any message that can be used to notify the approach to a cell that can be a destination.
- the detection unit 63 can notify the base station 10A using Proximity Indication.
- the detection unit 63 generates a message to be transmitted to the base station 10 ⁇ / b> A and outputs the message to the transmission unit 52.
- the transmission unit 52 transmits the message input from the detection unit 63 to the base station 10A.
- the handover processing unit 16 ⁇ / b> A of the base station 10 ⁇ / b> A provides information for acquiring the physical cell ID of the base station 10 that forms a cell that can be the destination of movement Send to.
- 10 A of base stations transmit the information used when acquiring physical cell ID of the small cell ccc to the mobile terminal 5.
- the frequency band of the macro cell AAA is 2.2 GHz
- the small cell ccc uses 800 MHz.
- the physical cell ID is used for the mobile terminal 5 to start communication via the small cell ccc. Therefore, the base station 10A notifies the mobile terminal 5 of information used for starting communication in the frequency band used by the mobile terminal 5 for communication in the small cell ccc by the procedure (53). It can be said.
- the handover processing unit 64 acquires the physical cell ID of the small cell ccc using the information notified from the base station 10A, and notifies the base station 10A of it.
- the handover processing unit 16A of the base station 10A requests the mobile terminal 5 to report information on the small cell of the movement destination (System Information, SI).
- the handover processing unit 64 of the mobile terminal 5 receives the broadcast information broadcast from the base station 10c, and acquires information such as CGI (Cell Global Identity) and TAI (Tracking Area Identify) from the broadcast information.
- CGI Cell Global Identity
- TAI Track Area Identify
- the handover processing unit 64 transmits the acquired information to the base station 10A.
- FIG. 22 is a diagram illustrating an example of communication according to the first embodiment.
- the macro cell DDD and the macro cell EEE are adjacent to each other.
- the macro cell DDD includes a small cell ggg and a small cell hhh
- the macro cell EEE includes a small cell jjj and a small cell kkk.
- FIG. 22 shows the trajectory of movement of the mobile terminal 5 at times T1 to T3. For example, T1 indicates the position of the mobile terminal 5 at time T1.
- the mobile terminal 5 is located in the macro cell DDD, and acquires information on a small cell that can be a destination from the base station 10D. Therefore, at time T1, the mobile terminal 5 acquires the location information of the small cells ggg, hhh, and jjj from the base station 10D, and discards the information on other small cells. For this reason, even if the mobile terminal 5 has not been in the small cell hhh, the mobile terminal 5 can detect that the small cell hh is nearby when it comes close to the small cell hhh.
- the mobile terminal 5 moves from the macro cell DDD to the small cell hh at time T2.
- the base station 10h notifies the mobile terminal 5 of the location information of the small cells ggg, jjj as small cells that can be the destination, and the mobile terminal 5 updates the location information table 71.
- the mobile terminal 5 can delete the location information about the cell hhh in communication and use the memory efficiently.
- the mobile terminal 5 moves from the small cell hhh to the small cell jjj at time T3.
- the base station 10j notifies the mobile terminal 5 of the position information of the small cells hhh and kkk as small cells that can be the destination of movement.
- the mobile terminal 5 updates the location information table 71 with the content notified from the base station 10j, and deletes the information on the small cell ggg. Therefore, the mobile terminal 5 does not have to hold information on cells that are unlikely to move directly from the cell used for communication at the time T3.
- the mobile terminal 5 can acquire information on the small cell that can be the movement destination from the base station 10 that is the handover destination. For this reason, the mobile terminal 5 can discover efficiently even if it is a small cell that has never been in the area. Further, since the mobile terminal 5 updates the contents of the location information table 71 in accordance with the notification from the base station 10, it holds the location information of small cells that are unlikely to move from the cell in which the mobile terminal 5 is located. You don't have to. For this reason, the mobile terminal 5 can effectively use the memory. Further, the mobile terminal 5 performs processing such as measurement of received power and acquisition of a physical cell ID when the distance to the small cell is equal to or less than a predetermined threshold. For this reason, it is possible to avoid a situation where power is consumed by trying to acquire a physical cell ID of a small cell that is so far away that communication is impossible.
- the macro cell base station 10 often manages the macro cell by dividing it into a plurality of sectors.
- 2nd Embodiment demonstrates the case where each base station 10 memorize
- the second embodiment is effective when it is desired to limit the amount of location information notified to the mobile terminal 5 due to reasons such as small cells being densely installed.
- the second embodiment will be described by taking as an example a case where the server 30 specifies a small cell that can be a destination for each sector and notifies each base station 10 of the small cell.
- the sector arrangement method in one macro cell is common to each base station 10 in advance, and the server 30 also has information for specifying the sector arrangement method. Assume that it is held in advance.
- each macro cell is divided into six sectors of 60 degrees with reference to the north direction from the base station installation position.
- the sector number is assumed to increase by one in the clockwise direction, assuming that the sector in the range of 60 degrees clockwise from the true north of the installation position of the base station is “1”.
- FIG. 23 shows an example of arrangement of macro cell sectors and small cells.
- the sector 1 and the sector 2 share a partial area with the small cell bbb, and the sector 4 shares a partial area with the small cell ccc.
- Sector 2 of the macro cell AAA is in contact with the small cell ddd.
- the sector 3 is in contact with the small cell eeee, and the sector 6 is in contact with the small cell aaa.
- the sector 5 of the macro cell AAA includes a small cell aaa.
- the sector 1 includes the small cell fff.
- the sector 5 of the macro cell BBB includes the small cell ddd, and further shares a part of the area with the small cell bbb.
- the sector 2 of the macro cell BBB is in contact with the small cell fff.
- the update unit 32 of the server 30 updates the macro cell information table 41 and the small cell information table 42 by the same method as in the first embodiment.
- the search unit 33 obtains the macro cell management table 43 by assigning a small cell (assigned small cell) that can be a destination of movement from the macro cell to each macro cell by the procedure described with reference to FIG. Next, the search unit 33 determines whether the number of allocated small cells exceeds a predetermined threshold for each macro cell. When the number of allocated small cells exceeds a predetermined threshold, the search unit 33 maps each sector in the macro cell and the small cell, and specifies a small cell sharing one or more points for each sector. The search unit 33 records information in which the identified small cell is associated with each sector of the macro cell in the macro cell management table 43.
- the update unit 32 and the search unit 33 perform the same process as in the first embodiment to create the macro cell management table 43c shown in FIG. Generate.
- the search unit 33 is set to manage the allocated small cells for each sector when the allocated small cells for each macro cell are 3 or more. Then, since the allocated small cells are 3 or more for both the macro cell AAA and the macro cell BBB, the search unit 33 determines to manage the allocated small cells for each sector.
- the search unit 33 identifies the arrangement shown in FIG. 23 by mapping the sector of the macro cell AAA and the macro cell BBB and the position of the small cell.
- the small cell shared at least one point with the sector 1 of the macro cell AAA is the small cell bbb. Similar processing is performed for other sectors as well, and the macro cell management table 43c (FIG. 10) is updated to the macro cell management table 43d shown in FIG.
- the server 30 manages small cells in units of sectors even when it is requested to switch the small cells to management in units of sectors for a certain macro cell.
- the method for generating the macro cell management table 43 and the small cell management table 44 is the same as when the number of allocated small cells exceeds the threshold.
- the server 30 may receive a request for switching to management in units of sectors from another device, or may receive a request from an operator via the input device 123.
- FIG. 25 is a flowchart for explaining an example of processing of the search unit 33 in the second embodiment.
- FIG. 25 shows an example of a method for updating the macro cell management table 43. Note that FIG. 25 is an example, and for example, it is possible to change the order of step S62 and step S63.
- variables r, s, and t are used.
- r is a variable that identifies a macro cell
- s is a variable that identifies a sector
- t is a variable that identifies a small cell.
- the search unit 33 determines an allocated small cell for each macro cell (step S61). The process in step S61 is as described with reference to FIG.
- the search unit 33 acquires the total number M of macro cells and sets the variable r to 1 (steps S62 and S63).
- the search unit 33 determines whether the allocated small cell exceeds a predetermined threshold for the r-th macro cell (step S64). If the allocated small cell does not exceed the predetermined threshold value, the search unit 33 further determines whether or not sector-by-sector management is requested for the r-th macro cell (No in step S64, step S65).
- the search unit 33 acquires the number of sectors (X) in the r-th macro cell and the number of allocated small cells (Y) in the r-th macro cell ( Yes in step S64, step S66). Similarly, also when management in units of sectors is requested for the r-th macro cell, the search unit 33 acquires the number of sectors and the number of allocated small cells for the r-th macro cell (Yes in step S65, step S66). .
- the search unit 33 sets both the variable s and the variable t to 1 (steps S67 and S68).
- the search unit 33 determines whether the sth sector and the tth allocated small cell share one or more points (step S69). When the sth sector and the tth allocated small cell share one or more points, the search unit 33 sets the tth small cell as the allocated small cell to the sth sector (Yes in step S69). Step S70).
- the search unit 33 increments the value of the variable t by 1, and determines whether the variable t is larger than the number of allocated small cells (Y) in the macro cell to be processed (steps S71 and S72).
- the search unit 33 repeats the processing after step S69 (No in step S72).
- the search unit 33 increments the value of the variable s by 1, and determines whether the variable s is larger than the number of sectors (X) in the macro cell to be processed (Yes in step S72). Steps S73 and S74).
- the search unit 33 repeats the processing after step S68 (No in step S74).
- the search unit 33 increments the value of the variable r by 1 and determines whether the variable r is larger than the number of macro cells (M) (Yes in step S74, steps S75, S76). When the variable r is equal to or smaller than M, the search unit 33 repeats the processing after step S64 (No in step S76). On the other hand, when the variable r exceeds M, the search unit 33 ends the process (Yes in step S76). If it is determined in step S65 that the sector unit management is not requested for the r-th macro cell, the search unit 33 performs the processing from step S75 onward in order to change the processing target macro cell (in step S65). No).
- the search unit 33 updates the small cell management table 44.
- the search unit 33 sets the allocated small cell for a certain small cell as a small cell that can move from the same sector as the sector to which the small cell is allocated. For example, it is assumed that the macro cell management table 43d (FIG. 24) is obtained. In this case, even if the search unit 33 searches the allocated small cell column using the small cell aaa as a key, it cannot find a sector in which a plurality of small cells are assigned small cells.
- the search unit 33 determines that there is no small cell that can be a destination from the small cell aaa, and does not set an allocated small cell in the small cell aaa as shown in FIG.
- the search unit 33 performs the same process for the small cell ccc, the small cell eeee, and the small cell fff.
- the search unit 33 searches the allocated small cell column using the small cell bbb as a key, in the sector 2 of the macro cell AAA, it is possible to specify that the small cell bbb and the small cell ddd are allocated small cells. For this reason, the search unit 33 determines that there is a possibility that the mobile terminal 5 may move from the small cell bbb to the small cell ddd, and sets the allocated small cell of the small cell bbb as the small cell ddd as illustrated in FIG. . The search unit 33 specifies that the small cell bbb and the small cell ddd are allocated small cells even in the sector 5 of the macro cell BBB.
- the small cell ddd is already a small cell assigned to the small cell bbb, so the small cell management table 44 is not changed.
- the search unit 33 performs the same process for the small cell ddd.
- FIG. 27 is a flowchart for explaining an example of processing of the search unit 33 in the second embodiment.
- FIG. 27 shows an example of a method for updating the small cell management table 44.
- the processing in steps S81 to S85 in FIG. 27 is the same as that in steps S31 to S35 in FIG.
- the search unit 33 specifies the small cell assigned to the same sector as the pth small cell. (Yes in step S85).
- the search unit 33 assigns small cells other than the pth small cell to small cells assigned to the same sector of the same macrocell as the sector to which the pth small cell is assigned, and assigns the small cell to the pth small cell.
- Step S86 Steps S87 to S90 are the same as steps S37 to S40 in FIG.
- the notification of the destination cell information from the server 30 to each base station 10, the notification of the location information from the base station 10 to the mobile terminal 5, and the processing at the mobile terminal 5 are the same as in the first embodiment.
- the server 30 notifies the allocated small cell for each sector.
- the base station 10 specifies the identifier of the sector used for communication with the mobile terminal 5 and transmits the positional information held in association with the sector corresponding to the mobile terminal 5 as the communication destination. To do. For this reason, for example, in the arrangement shown in FIG.
- the base station 10A notifies the mobile terminal 5 communicating in the sector 1 of the macro cell AAA, but informs the information of the small cell bbb. Will not notify you.
- the information of the sector that the base station 10 uses for communication with the mobile terminal 5 is specified by an arbitrary method such as specifying from the position information of the mobile terminal 5, for example.
- the case where one macro cell is divided into six sectors has been described as an example.
- the number of sectors included in one macro cell can be arbitrarily changed according to the implementation.
- a threshold used when determining whether to change the management of the small cell from the cell unit to the sector unit is arbitrarily set according to the implementation.
- each base station 10 stores a small cell that the mobile terminal 5 may be a destination for each sector, so the amount of position information to be notified to the mobile terminal 5 is stored. Can be suppressed. Therefore, the base station 10 can notify the mobile terminal 5 by focusing on the position information of the small cell that is relatively likely to be the destination of the mobile terminal 5.
- the allocation small cell determination method in the server 30 may be any of the first and second embodiments.
- the notification of the destination cell information from the server 30 to each base station 10 and the processing at the mobile terminal 5 are the same as in the first embodiment.
- the adjustment unit 17 of the base station 10 obtains the position information after the mobile terminal 5 is handed in.
- the period until transmission can be set in the information transmission list.
- the mobile terminal 5 having a high moving speed has a short stay time in a cell formed by the base station 10 and is not likely to access a nearby small cell.
- the adjustment unit 17 can adjust the timing for transmitting the position information according to the number of handovers to the base station 10 and the moving speed of the mobile terminal 5.
- FIG. 28 is an example of an information transmission list.
- the information transmission list includes information for determining the timing for transmitting the position information for each mobile terminal 5 that has handed in the cell formed by the base station 10.
- the priority timer is information indicating which of the two types of timers is preferentially used.
- the timer is a count value of the elapsed time from the hand-in. When the set time of the timer used preferentially and the count value (elapsed time) in the timer become the same value, the adjustment unit 17 transmits the position information to the mobile terminal 5.
- the base station timer is a common value determined for each base station 10.
- the adjustment unit 17 of the base station 10 counts the number of handovers generated in the base station 10 and compares the number of handovers that occurred within a certain time with a threshold Th.
- the adjustment unit 17 increases the value of the base station timer when the number of handovers occurring within a certain time exceeds the threshold Th. For example, in the initial setting of the base station 10, the value of the base station timer is 0 seconds. Then, when the base station timer is prioritized, the base station 10 transmits position information to the mobile terminal 5 with the mobile terminal 5 having been handed in as a trigger. When the number of handovers occurring within a certain time exceeds the threshold Th, the adjustment unit 17 increases the value of the base station timer.
- the adjustment unit 17 sets the value of the base station timer to 5 seconds as shown in FIG. Then, even if the mobile terminal 5 has handed in, the adjustment unit 17 does not notify the mobile terminal 5 of position information until 5 seconds have passed since the hand-in. Note that the number of handovers that occur during a certain period of time may be compared with a plurality of threshold values. In this case, it is assumed that the set value of the base station timer becomes larger as the value of the handover occurring within a certain time is larger.
- the speed timer is a timer set for each mobile terminal 5.
- the adjustment unit 17 acquires the moving speed of the mobile terminal 5 that has been handed in.
- the method for acquiring the moving speed of the mobile terminal 5 is arbitrary.
- the base station 10 includes the calculation unit 18, the calculation unit 18 calculates the speed of the mobile terminal 5 at the timing of hand-in, and associates the obtained value with the identifier of the mobile terminal 5.
- the base station 10 may acquire the moving speed of the mobile terminal 5 from the handover source base station 10 during the handover process.
- the adjustment unit 17 holds information in which the moving speed of the mobile terminal 5 is associated with the set value of the speed timer in advance.
- the adjustment unit 17 sets the speed timer to 0 seconds for the terminals identified by the terminal identifiers of 11111111 and 44444444, and sets the speed timer of the terminal identified by the terminal identifier of 222222222 to 5 seconds. ing. Further, since the moving speed of the terminal identified by the terminal identifier of 333333333 is faster than the moving speed of other terminals, the speed timer is set to 10 seconds.
- the priority timer is a speed timer for any terminal. Therefore, when the elapsed time from the hand-in becomes the same value as the speed timer setting time for each mobile terminal 5, the adjustment unit 17 transmits position information to the mobile terminal 5. Accordingly, the adjustment unit 17 transmits the position information to the terminals identified by the terminal identifiers 11111111 and 44444444 at the time of hand-in. On the other hand, the adjustment unit 17 transmits position information to the terminal identified by the terminal identifier of 222222222 after 5 seconds from the hand-in, and to the terminal identified by the terminal identifier of 111111111, the position after 10 seconds from the hand-in. Send information.
- FIG. 29 is a sequence diagram illustrating an example of a position information notification method according to the third embodiment.
- Procedures (61) and (62) are the same as procedures (21) and (22) described with reference to FIG.
- the adjustment unit 17 adds the information of the mobile terminal 5 that has handed in to the information transmission list.
- the information transmission list setting method is as described with reference to FIG.
- the adjustment unit 17 acquires the location information by accessing the location information table 21 in the storage unit 20.
- the adjustment unit 17 generates a message to be transmitted to the mobile terminal 5 using the acquired position information.
- the adjustment unit 17 refers to the information transmission list and holds the message until the transmission timing of the generated message comes.
- the adjustment unit 17 When the timer value becomes the same as the set time of the timer used preferentially, the adjustment unit 17 outputs a message including position information to the transmission unit 14.
- the transmission unit 14 transmits the message input from the adjustment unit 17 to the mobile terminal 5.
- the mobile terminal 5 updates the location information table 71 using the message received from the base station 10.
- the base station 10 determines, using the moving speed of the mobile terminal 5 or the like, whether the mobile terminal 5 is likely to use the notified location information. Furthermore, the adjustment unit 17 sets a long time from the hand-in to the transmission of the position information for the mobile terminal 5 that is unlikely to use the position information. For this reason, the mobile terminal 5 having a high moving speed may have moved out of the communication area of the base station 10 before receiving the position information from the base station 10. In this case, the mobile terminal 5 uses Do not perform processing such as receiving location information that is not expected or holding location information. For this reason, the processing burden of the mobile terminal 5 can be reduced.
- the base station 10 acquires position information from the server 30 has been described as an example, but the base station 10 can also acquire position information from a device other than the server 30.
- the server 30 and the base station 10 may acquire transmission power at each base station 10 instead of the cell radius.
- the value of the received power P R can be a cell radius up to a distance below a predetermined threshold.
- P T transmitted power (W)
- G R is the received gain
- G T is transmission gain
- lambda is the wavelength
- D is the distance.
- the mobile terminal 5 may be modified to determine whether to update the location information table 71 using the number of handover occurrences per unit time. .
- the update unit 61 counts the number of handover occurrences per unit time. If the number of handover occurrences per unit time exceeds a predetermined threshold, the updating unit 61 does not update the location information table 71 even if the location information is notified from the base station 10. If the location information table 71 is not updated, the small cell may not be detected correctly. However, the load on the mobile terminal 5 is reduced by not performing the process associated with the location information table 71 update.
- the updating unit 61 monitors the remaining amount of power of the mobile terminal 5, and can reduce power consumption by stopping the updating of the position information table 71 when the remaining amount of power decreases.
- the mobile terminal 5 modified in this way is suitable for use in a place where the number of small cells is so large that a small cell can be found without updating the location information table 71 at every handover, for example. Further, the mobile terminal 5 modified in this way can be used in combination with the third embodiment.
- the adjustment unit 17 can also be modified to transmit a message including location information to the mobile terminal 5 after determining whether the mobile terminal 5 exists in the cell when the timer expires. .
- the adjustment unit 17 can search a list in which the identification information of the mobile terminal 5 in communication is recorded, using the identification information of the mobile terminal 5 to which the message is transmitted as a key.
- the adjustment unit 17 transmits a message to the mobile terminal 5.
- the adjustment unit 17 stops transmitting the message to the mobile terminal 5 and discards the message.
- the base station 10 does not need to transmit the position information to the mobile terminal 5 that is unlikely to use the position information, so the processing load on the base station 10 is reduced.
- the small cell base station can also be modified so as to retain information on a macro cell that shares one or more points with the small cell.
- information on the macro cell sharing one or more points with the small cell is also notified to the mobile terminal 5.
- the mobile terminal 5 handed in to the small cell b included in the macro cell A can acquire the small cell sharing one or more points with the macro cell A, the position information of the macro cell A, the cell radius, and the like. Then, the mobile terminal 5 can determine whether to enter the area of the macro cell A when leaving the small cell b.
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Abstract
Description
図2は、移動端末5と基地局10(10a~10c)の構成の例を示す。図2に示す例では、基地局10a~10cは、ネットワーク1を介してサーバ30にアクセスすることができる。
図6は、マクロセルとスモールセルの配置の例を示す。以下、マクロセルの識別子は、3文字のアルファベットの大文字が連続した文字列で表し、スモールセルの識別子は、3文字のアルファベットの小文字が連続した文字列で表す。例えば、図6のセルAAAやセルBBBはマクロセルであり、セルaaa、bbbなどは、スモールセルである。また、理解しやすくするために、物理セルIDと各セルの識別子を同じ文字列で表す。例えば、セルAAAの物理セルIDはAAAである。図6の例では、マクロセルAAAは、スモールセルaaaとスモールセルbbbを包含しており、スモールセルcccと一部の領域を共有している。さらに、マクロセルAAAは、スモールセルdddとスモールセルeeeに接しているので、スモールセルdddおよびスモールセルeeeとも少なくとも1点を共有しているといえる。一方、マクロセルBBBは、スモールセルdddとスモールセルfffを包含しており、さらに、スモールセルbbbと一部の領域を共有している。
図7は、マクロセル情報テーブル41とスモールセル情報テーブル42の例を示す。図7の例では、マクロセル情報テーブル41とスモールセル情報テーブル42のいずれも、各セルに割り当てられた物理セルIDに対応付けて、そのセルを形成する基地局の設置位置、通信に使用される周波数帯域、セル半径が記録されている。図7の例では、位置情報は、緯度と経度の組み合わせであり、末尾にxxが付されている値が緯度(北緯)、末尾にyyが付されている値が経度(東経)であるものとする。以下の説明では、マクロセルAAAとマクロセルBBBは、同じ周波数帯域を使用しているものとする。一方、スモールセルaaa~fffは、いずれも、マクロセルAAAやマクロセルBBBとは異なる周波数帯域を通信に使用する。さらに、スモールセル同士では、通信に使用される周波数帯域は同じであっても異なっていても良い。図7の例では、マクロセルAAAとマクロセルBBBはいずれも、2.2GHzの帯域で通信を行う。一方、スモールセルaaa、ccc、ddd、eeeは、800MHzの周波数帯域を使用するが、スモールセルbbbとfffは、900MHzの周波数帯域を使用する。
物理セルID:AAA
位置情報 :北緯35.730541度、東経139.71294度
周波数帯域 :2.2GHz
セル半径 :500m
検索部33は、取得した情報を用いて、図10に示すマクロセル管理テーブル43aを生成する。
マクロセル管理テーブル43とスモールセル管理テーブル44の更新処理が終わると、サーバ30は、移動先セル情報を基地局10に通知する。ここで、「移動先セル情報」は、移動先セル情報の宛先の基地局10と通信中の移動端末5にとって、移動先となり得るセルの位置情報を含む。移動先セル情報には、宛先となる基地局10の割り当てスモールセルの物理セルIDに、各セルの位置情報を含む任意の情報が対応付けられているものとする。以下の説明では、移動先セル情報の宛先の区別を容易にするために、動作を行っている基地局10が形成している物理セルIDの1文字目のアルファベットを、符号の最後に記載することがある。例えば、基地局10AはマクロセルAAAを形成しており、基地局10bはスモールセルbbbを形成している。また、位置情報テーブル21Aは、基地局10Aに保持されている位置情報テーブル21である。
図17は、基地局10が移動端末5に位置情報を通知する際に行う処理の例を説明するシーケンス図である。
次に、基地局10から位置情報を受信した後で移動端末5によって行われる処理の例を説明する。以下の説明でも、移動端末5は、基地局10Bから基地局10Aにハンドオーバしてきたとする。この場合、移動端末5は、マクロセルAAAにハンドインする。なお、以下の説明では、基地局10は、移動端末5に対して移動先となり得るスモールセルの位置情報の他に、周波数帯域やセル半径も通知する場合を例として説明するが、基地局10がセル半径などを通知しない場合も、以下と同様の処理が行われる。
マクロセルの基地局10は、マクロセルを複数のセクタに分けて管理することが多い。第2の実施形態では、各基地局10が、セクタごとに、移動端末5が移動先とする可能性があるスモールセルを記憶する場合について説明する。第2の実施形態は、スモールセルが密集して設置されているなどの理由により、移動端末5に通知する位置情報の量を限定したい場合に効果的である。
第3の実施形態では、基地局10が移動端末5へ位置情報を通知するタイミングを変更可能な場合について説明する。なお、第3の実施形態では、サーバ30での割り当てスモールセルの決定方法は、第1および第2の実施形態のいずれでもよい。また、サーバ30から各基地局10への移動先セル情報の通知、および、移動端末5での処理は、第1の実施形態と同様である。
なお、本発明の実施形態は、上述の構成又は方法に限られるものではなく、様々に変形可能である。以下にその例をいくつか述べる。
5 移動端末
10 基地局
11 信号処理部
12 無線処理部
13、31、51 受信部
14、35、52 送信部
15、32、61 更新部
16、64 ハンドオーバ処理部
17 調整部
18 計算部
20、40、70 記憶部
21、71 位置情報テーブル
30 サーバ
33 検索部
34 選択部
41 マクロセル情報テーブル
42 スモールセル情報テーブル
43 マクロセル管理テーブル
44 スモールセル管理テーブル
62 特定部
63 検出部
101、111 アンテナ
102、112 アンプ
103、113 ベースバンド処理回路
104、114、121 プロセッサ
105、115、122 メモリ
106 伝送路インタフェース
123 入力装置
124 出力装置
125 バス
126 外部記憶装置
127 媒体駆動装置
128 可搬記憶媒体
129 ネットワーク接続装置
Claims (12)
- 第1のセルに在圏する移動端末と無線通信が可能な基地局装置であって、
前記移動端末の移動先となり得る第2のセルの位置情報を記憶する記憶部と、
前記移動端末に前記第2のセルの位置情報を送信し、前記移動端末に前記位置情報を用いて前記第2のセルへの接近を検知させる送信部
を備える基地局装置。 - 第1の周波数帯域での通信が行われる前記第1のセルから、前記第1の周波数帯域とは異なる第2の周波数帯域での通信が行われる前記第2のセルへ、前記移動端末がハンドオーバするための処理を行うハンドオーバ処理部
をさらに備え、
前記ハンドオーバ処理部は、前記移動端末が前記第2のセルへの接近を検知したことを前記移動端末から通知された後に、前記移動端末が前記第2の周波数帯域での通信の開始に使用する情報を、前記送信部を介して、前記移動端末に送信する
ことを特徴とする請求項1に記載の基地局装置。 - 前記第1のセルを用いた通信の開始を要求する要求メッセージを、前記移動端末から受信する受信部
をさらに備え、
前記送信部は、前記受信部が前記要求メッセージを受信すると、前記位置情報を前記移動端末に送信する
ことを特徴とする請求項1または2に記載の基地局装置。 - 前記第1のセルを用いた通信の開始を要求する要求メッセージを、前記移動端末から受信する受信部と、
前記移動端末の移動速度を計算する計算部と、
前記要求メッセージの受信から、前記位置情報の送信を行うまでの時間間隔を、前記移動速度が速いほど長くなるように調整する調整部
をさらに備え、
前記送信部は、前記時間間隔が経過すると、前記位置情報を前記移動端末に送信する
ことを特徴とする請求項1または2に記載の基地局装置。 - 前記記憶部は、前記第1のセルを分割することにより得られる複数のセクタの各々を識別するセクタ識別子と、前記セクタ識別子で識別されるセクタと少なくとも1点を共有するセルを対応付けて記憶し、
前記送信部は、前記移動端末が位置するセクタと少なくとも1点を共有するセルの位置情報を、前記移動端末に通知する
ことを特徴とする請求項1~4のいずれか1項に記載の基地局装置。 - 第1のセルで基地局装置と通信可能な移動端末であって、
前記第1のセルからの移動先となり得る第2のセルの位置情報を前記基地局装置から受信する受信部と、
前記移動端末の位置を特定する特定部と、
前記位置情報および前記移動端末の位置を用いて前記第2のセルへの接近を検出する検出部と、
前記第2のセルへの接近を通知する通知情報を、前記基地局装置に送信する送信部
を備える移動端末。 - 第1の周波数帯域での通信が行われる前記第1のセルから、第2の周波数帯域で通信が行われる前記第2のセルへハンドオーバするための処理を行うハンドオーバ処理部
を備え、
前記送信部は、前記第1の周波数帯域を使用して、前記通知情報を前記基地局装置に送信し、
前記受信部は、前記第2の周波数帯域での通信の開始に用いる開始情報を、前記送信部が前記通知情報を送信した後に、前記基地局装置から受信し、
前記ハンドオーバ処理部は、前記開始情報を用いて、前記第1のセルから前記第2のセルへのハンドオーバを行う
ことを特徴とする請求項6に記載の移動端末。 - 前記第1のセルが複数のセクタに分割されており、前記移動端末は、前記複数のセクタのうちの通信対象のセクタに位置し、
前記受信部は、前記通信対象のセクタと少なくとも1点を共有するセルの位置情報を、取得する
ことを特徴とする請求項6または7に記載の移動端末。 - 前記検出部は、前記移動端末の位置との距離が閾値以下のセルを検出することにより、前記第2のセルを検出する
ことを特徴とする請求項6~8のいずれか1項に記載の移動端末。 - 第1のセルを提供する基地局装置と、
前記第1のセルで基地局装置と通信可能な移動端末、
を備え、
前記基地局装置は、前記移動端末の移動先となり得る第2のセルの位置情報を、前記移動端末に送信し、
前記移動端末は、
前記移動端末の位置を特定し、
前記位置情報および前記移動端末の位置を用いて前記第2のセルへの接近を検出し、
前記第2のセルへの接近を通知する通知情報を、前記基地局に送信する
ことを特徴とする無線通信システム。 - 前記第1のセルで第1の周波数帯域を用いた通信が行われ、
前記第2のセルで第2の周波数帯域での通信が行われ、
前記基地局装置は、前記通知情報を受信すると、前記移動端末が前記第2の周波数帯域での通信の開始に使用する開始情報を、前記移動端末に送信し、
前記移動端末は、前記開始情報を用いて、前記第2のセルを用いた通信を開始する
ことを特徴とする請求項10に記載の無線通信システム。 - 前記基地局装置は、
前記基地局装置との通信の開始を要求する要求メッセージを、前記移動端末から受信すると、前記移動端末の移動速度を計算し、
前記要求メッセージの受信から、前記位置情報の送信を行うまでの時間間隔を、前記移動速度が速いほど長くなるように調整し、
前記要求メッセージの受信から前記時間間隔が経過すると、前記位置情報を前記移動端末に送信する
ことを特徴とする請求項10または11に記載の無線通信システム。
Priority Applications (4)
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EP13891077.3A EP3032876A4 (en) | 2013-08-05 | 2013-08-05 | BASE STATION APPARATUS, MOBILE TERMINAL AND WIRELESS COMMUNICATION SYSTEM |
JP2015530573A JP6123898B2 (ja) | 2013-08-05 | 2013-08-05 | 基地局装置、移動端末、および、無線通信システム |
US14/988,282 US9832702B2 (en) | 2013-08-05 | 2016-01-05 | Base station device, mobile terminal, and radio communication system |
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Cited By (3)
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WO2020202382A1 (ja) * | 2019-03-29 | 2020-10-08 | 本田技研工業株式会社 | 端末装置、通信システム、通信方法、及びプログラム |
JP2021087088A (ja) * | 2019-11-27 | 2021-06-03 | パナソニックIpマネジメント株式会社 | 通信制御装置、通信制御方法、及び、通信システム |
WO2023188143A1 (ja) * | 2022-03-30 | 2023-10-05 | 日本電気株式会社 | 通信制御装置、端末装置、移動体、通信システム、通信制御商法、及びプログラム |
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JP2016184889A (ja) * | 2015-03-26 | 2016-10-20 | キヤノン株式会社 | 通信装置、通信装置の制御方法及びプログラム |
US10397840B2 (en) | 2016-11-15 | 2019-08-27 | At&T Intellectual Property I, L.P. | Method and apparatus for communication device handover |
US10278108B2 (en) | 2017-07-17 | 2019-04-30 | At&T Intellectual Property I, L.P. | Method and apparatus for coordinating wireless resources in a communication network |
US10085199B1 (en) | 2017-07-17 | 2018-09-25 | At&T Intellectual Property I, L.P. | Method and apparatus for directing wireless resources in a communication network |
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CN113574933A (zh) * | 2019-03-29 | 2021-10-29 | 本田技研工业株式会社 | 终端装置、通信系统、通信方法以及程序 |
JP7285918B2 (ja) | 2019-03-29 | 2023-06-02 | 本田技研工業株式会社 | 端末装置、通信システム、通信方法、及びプログラム |
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JP2021087088A (ja) * | 2019-11-27 | 2021-06-03 | パナソニックIpマネジメント株式会社 | 通信制御装置、通信制御方法、及び、通信システム |
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Also Published As
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US9832702B2 (en) | 2017-11-28 |
EP3032876A4 (en) | 2016-07-20 |
JPWO2015019406A1 (ja) | 2017-03-02 |
US20160135106A1 (en) | 2016-05-12 |
JP6123898B2 (ja) | 2017-05-10 |
EP3032876A1 (en) | 2016-06-15 |
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