WO2014010289A1 - 通信制御装置、通信制御方法及び端末装置 - Google Patents
通信制御装置、通信制御方法及び端末装置 Download PDFInfo
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- WO2014010289A1 WO2014010289A1 PCT/JP2013/061502 JP2013061502W WO2014010289A1 WO 2014010289 A1 WO2014010289 A1 WO 2014010289A1 JP 2013061502 W JP2013061502 W JP 2013061502W WO 2014010289 A1 WO2014010289 A1 WO 2014010289A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
- H04B17/30—Monitoring; Testing of propagation channels
- H04B17/309—Measuring or estimating channel quality parameters
- H04B17/345—Interference values
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
- H04B17/30—Monitoring; Testing of propagation channels
- H04B17/382—Monitoring; Testing of propagation channels for resource allocation, admission control or handover
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- 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
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
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- H04W36/16—Performing reselection for specific purposes
- H04W36/20—Performing reselection for specific purposes for optimising the interference level
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/18—TPC being performed according to specific parameters
- H04W52/24—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters
- H04W52/243—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters taking into account interferences
- H04W52/244—Interferences in heterogeneous networks, e.g. among macro and femto or pico cells or other sector / system interference [OSI]
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- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/38—TPC being performed in particular situations
- H04W52/40—TPC being performed in particular situations during macro-diversity or soft handoff
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- H04J11/00—Orthogonal multiplex systems, e.g. using WALSH codes
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- 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
- H04W36/0058—Transmission of hand-off measurement information, e.g. measurement reports
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- H04W36/142—Reselecting a network or an air interface over the same radio air interface technology
Definitions
- the present disclosure relates to a communication control device, a communication control method, and a terminal device.
- a business operator places small cells such as pico cells and femto cells in a macro cell. That is, the business operator adopts a heterogeneous network. Thereby, the provider can obtain further communication capacity due to the cell division gain.
- a heterogeneous network interference may occur between the macro cell and the small cell. Therefore, a technique for suppressing interference between the macro cell and the small cell has been studied.
- Patent Document 1 when a frequency band is shared between a macro cell and a small cell in a heterogeneous network, the output power of each terminal device and base station is appropriately adjusted using the cooperation manager. Thus, a technique for suppressing interference is disclosed.
- Patent Document 1 does not consider interference in a special case such as handover of a terminal device in a heterogeneous network. Therefore, for example, when a terminal apparatus is handed over, interference between the macro cell and the small cell may occur.
- a macro cell that performs radio communication using the FDD scheme using a frequency band and overlaps with a part or the whole of a small cell that performs radio communication using the TDD scheme using the frequency band.
- One or more wireless communication units that wirelessly communicate with the terminal device within the macro cell, and one or more wireless communication units within the macro cell at the time of handover of the terminal device that enables the terminal device to wirelessly communicate with the small cell.
- a communication control device comprising: an acquisition unit that acquires a measurement result of the degree of interference between another terminal device and the terminal device; and a control unit that controls the handover based on the measurement result.
- a macro cell in which radio communication in the FDD scheme is performed using a frequency band and a part or the whole of a small cell in which radio communication in the TDD scheme is performed using the frequency band
- One or more wireless communications in the macro cell during the handover of the terminal device enabling wireless communication with the terminal device in the overlapping macro cell and the terminal device enabling wireless communication in the small cell A communication control method is provided that includes obtaining a measurement result of the degree of interference between the other terminal device and the terminal device, and controlling the handover based on the measurement result.
- a small cell partially or wholly overlaps with a macro cell in which radio communication in the FDD scheme is performed using the frequency band, and wireless communication in the TDD scheme is performed using the frequency band.
- the terminal device can perform wireless communication between the terminal device and one or more other terminal devices that perform wireless communication in the macro cell at the time of handover of the terminal device.
- a communication control device comprising: an acquisition unit that acquires a measurement result of the degree of interference in and a control unit that controls the handover based on the measurement result.
- a macro cell in which radio communication in the FDD scheme is performed using a frequency band and a part or the whole of a small cell in which radio communication in the TDD scheme is performed using the frequency band
- the wireless communication unit that wirelessly communicates with the base station of the macrocell in the overlapping macrocell, and wirelessly communicates with the base station of the small cell within the small cell, and the own device wirelessly communicates with the small cell.
- a control unit that performs control for measuring the degree of interference between one or more other terminal devices that perform wireless communication in the macro cell and the own device during handover of the own device to be enabled
- a terminal device is provided in which the handover is controlled based on the result of the measurement.
- both the FDD method and the TDD method are specified by 3GPP.
- a single frequency is used for both uplink and downlink in time division. Since time division is adopted in the TDD system, the maximum communication speed in the TDD system is theoretically lower than the maximum communication speed in the FDD system.
- there are significant advantages in terms of mounting such as low costs for terminal devices and base stations.
- radio control based on channel duality (Reciprocity) between the uplink and the downlink can be executed. Therefore, the base station can easily estimate the downlink radio channel using the uplink radio channel. Therefore, radio control between the base station and the terminal device can be significantly simplified.
- the TDD scheme it is possible to change the uplink and downlink channel configurations, that is, the combination of link directions for each subframe included in a radio frame. Therefore, it is possible to flexibly adjust the amount of uplink radio resources and the amount of downlink radio resources according to actual traffic conditions.
- the operation cost of a radio communication system can be reduced in the TDD scheme.
- the manufacturing cost of the terminal device can be reduced.
- a TDD terminal device does not require an expensive antenna duplexer having a large mounting area, unlike the antenna duplexer of an FDD terminal device.
- the TDD terminal device uplink communication and downlink communication are not performed simultaneously. For this reason, a major problem in high-frequency circuit design, that is, sensitivity deterioration due to interference of the transmission signal to the reception circuit, is not caused in principle. This problem exists as a major concern in the circuit design of FDD terminal devices. Therefore, the high-frequency amplifier circuit of the TDD terminal device can be mounted at a lower cost than the high-frequency amplifier circuit of the FDD terminal device.
- the manufacturing cost of the terminal device can be reduced in the TDD system from the viewpoint of the antenna duplexer, the high frequency amplifier circuit, and the like.
- HetNet heterogeneous network
- either one of the FDD method and the TDD method is adopted in the LTE system.
- the FDD method and the TDD method are adopted in the HetNet.
- a business operator can employ an FDD scheme in a macro cell and a TDD scheme in a small cell.
- FIG. 1 is an explanatory diagram for explaining an example of assumed HetNet.
- a macro cell 10 and an eNodeB (hereinafter referred to as “eNB”) 11 of the macro cell 10 are illustrated.
- a small cell 30 and a Home eNodeB (hereinafter referred to as “HeNB”) 31 of the small cell 30 are shown.
- the small cell 30 partially or entirely overlaps with the macro cell 10.
- the macro cell 10 overlaps with a part or the whole of the small cell 30.
- UE21 is shown.
- the UE 21 a and the UE 21 b are located in the macro cell 30, but are not located in the small cell 30.
- the UE 21c is located in the small cell.
- the macro cell 10 performs wireless communication using the FDD method. That is, the eNB 11 performs radio communication with the UE 21a and the UE 21b in the macro cell 10 using the FDD scheme. More specifically, the eNB 11 transmits signals to the UE 21a and the UE 21b using the downlink frequency band, and receives signals from the UE 21a and the UE 21b using the uplink frequency band.
- wireless communication by the TDD scheme is performed using the same frequency band as the frequency band used by the eNB 11. That is, the HeNB 31 wirelessly communicates with the UE 21c in the small cell 30 by the TDD method using the FDD frequency band. More specifically, the HeNB 31 transmits a signal to the UE 21c using the frequency band in the downlink subframe, and receives a signal from the UE 21c using the frequency band in the uplink subframe.
- the macro cell 10 and the small cell 30 not only use the same frequency band, but also use the frequency band at the same time.
- the operator may be able to increase system capacity at low cost. It is desirable in the long term that the convenience of the user is improved through the improvement of the frequency use efficiency and the reduction of the cost.
- the HetNet described with reference to FIG. 1 that is, when FDD wireless communication is performed in a macro cell and TDD wireless communication is performed in a small cell, new interference that is not expected in the conventional HetNet occurs.
- the UE 21c that performs radio communication in the small cell 30 uses the downlink frequency band and / or the up frequency band for the macro cell 10, Wireless communication using the TDD method is performed.
- the UE 21c transmits not only a signal but also a signal in the downlink frequency band.
- the UE 21c not only transmits a signal but also receives a signal in the up frequency band.
- interference in the assumed HetNet will be described more specifically.
- FIG. 2 is an explanatory diagram for explaining an example of interference in the downlink frequency band in the assumed heterogeneous network.
- FIG. 3 is an explanatory diagram for explaining an example of interference in the uplink frequency band in the assumed heterogeneous network.
- the macro cell 10 the eNB 11, the UE 21, the small cell 30, and the HeNB 31 are illustrated as in FIG. 1.
- the macro cell 10 performs wireless communication using the FDD method
- the small cell 30 performs wireless communication using the TDD method.
- the same frequency band is used at the same time.
- the downlink frequency band is a frequency band used for the downlink in the macro cell 10 in which the FDD scheme is adopted.
- candidates for signal transmission those that can become interference sources are indicated by D1 to D8.
- signal transmission from the eNB 11 to the UE 21a and the UE 21b is normal signal transmission in the macro cell 10
- signal transmission between the HeNB 31 and the UE 21c is normal signal transmission in the small cell 30. Signal transmission.
- the uplink frequency band is a frequency band used for the uplink in the macro cell 10 employing the FDD scheme.
- candidates for signal transmission those that can be interference sources are indicated by U1 to U8.
- the signal transmission from the UE 21a and the UE 21b to the eNB 11 is a normal signal transmission in the macro cell 10
- the signal transmission between the HeNB 31 and the UE 21c is a normal signal transmission in the small cell 30. Signal transmission.
- the same frequency band has not been used at the same time. That is, in the small cell 30, a frequency band different from the frequency band used in the macro cell 10 is used. Therefore, it is possible to prevent interference between the frequency bands in the macro cell 10 and the small cell 30 by discriminating signals by the high frequency filter circuit.
- the macro cell 10 performs FDD wireless communication
- the small cell 30 performs TDD wireless communication
- the macro cell 10 and the small cell 30 have the same frequency band. If both are used simultaneously, another interference becomes a problem. That is, as shown in Table 1 and Table 2, interference between the devices (UE21c and HeNB31) in the small cell 30 and the UEs 21a and UE21b in the macrocell 10 (interference by signal transmissions D1, D3, U5, and U6) ) Is the biggest problem.
- new interference different from any conventional one may occur.
- the signal transmissions D5 and D6 do not exist in the downlink frequency band, no interference is generated in principle.
- the signal transmissions U7 and U8 do not exist in the up frequency band, and thus do not generate interference in principle.
- the transmission power of the UE 21c and the HeNB 31 that perform radio communication in the small cell 30 is small, and the distance between the eNodeB 11 and the small cell 30, interference from the signal transmissions D2, D4, U2, and U4 can be said to be minute.
- the interference by signal transmission U1 and U3 is also small, considering that the transmission power of UE21c and HeNB31 which wirelessly communicates in the small cell 30 is small.
- Patent Document 1 Although interference during normal communication in HetNet is considered, interference in a special case such as a handover of a terminal device in HetNet is not considered. Therefore, even if the invention of Patent Literature 1 is used, interference between the macro cell and the small cell may occur, for example, when the terminal device is handed over. Hereinafter, the interference during the handover will be described more specifically.
- the target UE 21 of the handover performs random access as an initial procedure.
- the UE 21 first transmits a special signal called a preamble signal to a target cell base station on a random access channel (hereinafter referred to as “RACH”). That is, the UE 21 transmits a preamble signal to the HeNB 31 of the small cell 30.
- RACH random access channel
- the output power of the preamble signal is normally determined based on the path loss from the HeNB 31 estimated in the downlink channel of the UE 21.
- the output power of the preamble signal of UE21 may become excessive. If the random access is performed in the downlink frequency band, the transmission of the preamble signal corresponds to the signal transmission D1 shown in FIG. Therefore, interference may occur between the UE 21 close to the small cell 30 among the UEs 21 in the macro cell 10 and the UE 21 that is the target of the handover.
- the handover target UE 21 not only transmits a signal in the uplink frequency band after handover from the macro cell 10 to the small cell 30 in the uplink frequency band, A signal is received. Therefore, after the handover, when the UE 21 that performs radio communication in the macro cell 10 exists in the vicinity of the small cell 30, the signal transmission from the UE 21 to the UE 21 that is the handover target (corresponding to the signal transmission U5 illustrated in FIG. 3) Interference can occur.
- interference can occur in each of the downlink frequency band and the uplink frequency band.
- interference during inter-frequency handover Next, interference at the time of inter-frequency handover in the assumed HetNet will be described.
- interference during inter-frequency handover in a small cell becomes a problem.
- interference during the handover will be specifically described.
- signal transmission from the UE close to the small cell among the UEs in the macro cell to the target UE for handover causes interference.
- Specific interference is the same as interference for inter-cell handover from a macro cell to a small cell in the uplink frequency band. That is, in the handover to the uplink frequency in the small cell, if the UE 21 that performs radio communication in the macro cell 10 exists in the vicinity of the small cell 30 after the handover, interference due to signal transmission from the UE 21 to the UE 21 that is the target of the handover. Can occur.
- interference can occur in each of the downlink frequency band and the uplink frequency band during inter-frequency handover in a small cell.
- FIG. 4 is an explanatory diagram showing an example of a schematic configuration of the wireless communication system 1 according to the present embodiment.
- the radio communication system 1 includes an eNB 100 of the macro cell 10, a UE 200, and a HeNB 300 of the small cell 30.
- the UE 200a is a UE that is a target of handover
- the UE 200b is a UE that performs radio communication in the macro cell 10 (more strictly speaking, an area excluding the small cell 30 in the macro cell 10).
- wireless communication similar to the wireless communication on the assumed HetNet described with reference to FIG. 1 is performed.
- wireless communication using the FDD method is performed using a frequency band. That is, the eNB 100 wirelessly communicates with the UE 200 in the macro cell 10 by the FDD method using the frequency band. More specifically, eNB100 transmits the signal to UE200 using a downlink frequency band, and receives the signal from UE200 using an uplink frequency band.
- wireless communication by the TDD scheme is performed using the same frequency band as the frequency band used by the eNB 100. That is, the HeNB 300 performs radio communication with the UE 200 in the small cell 30 by the TDD method using the frequency band. More specifically, the HeNB 300 transmits a signal to the UE 200 using the frequency band in a downlink subframe, and receives a signal from the UE 200 using the frequency band in an uplink subframe.
- the wireless communication system not only the same frequency band is used in the macro cell 10 and the small cell 30, but also the frequency band is used simultaneously.
- FIG. 5 is an explanatory diagram for explaining the outline of the operation of the wireless communication system 1 for the downlink frequency band. Referring to FIG. 5, operations of the wireless communication system 1 for the downlink frequency band are shown in (1) to (7).
- the eNB 100 instructs the UE 200a to be handed over to measure the degree of interference (hereinafter referred to as “interference level”) between the UE 200a and the one or more other UEs 200.
- interference level the degree of interference
- the eNB 100 instructs one or more other UEs 200 (for example, the UE 200b) that perform radio communication in the macro cell 10 to measure the interference level between the UE 200a and the one or more other UEs 200.
- the handover target UE 200a transmits a signal for measuring an interference level (hereinafter referred to as an “interference level measurement signal”).
- Each of the one or more other UEs 200 receives the interference level measurement signal and measures the interference level between the UE 200a and the own apparatus in the downlink frequency band.
- Each of the one or more other UEs 200 (for example, the UE 200b) transmits an interference level measurement result to the eNB 100.
- the eNB 100 controls the parameters of the UE 200a regarding the RACH based on the measurement result. More specifically, for example, the eNB 100 determines the transmission power of the UE 200a in the RACH so as not to cause interference from the UE 200a to the one or more other UEs 200 (for example, the UE 200b) based on the measurement result. . Then, the eNB 100 notifies the UE 200a of the determined transmission power.
- the UE 200a After setting the received parameter (for example, transmission power in RACH), the UE 200a transmits a random accelerator preamble signal to the HeNB 300.
- the received parameter for example, transmission power in RACH
- the wireless communication system 1 operates as described in (1) to (7) above, for example. Based on the measurement result, it is possible to predict how much interference may occur from one UE 200a to be handed over to one or more other UEs 200 close to the small cell 30. And based on the said measurement result, the said interference can be suppressed by changing the parameter (for example, transmission power in RACH) of UE200a regarding RACH. For example, when it is determined from the measurement result that the interference level is high, the interference can be suppressed by reducing the transmission power of the UE 200a in the RACH. In this way, it is possible to suppress interference that occurs during inter-cell handover from the macro cell 10 to the small cell 30 in the downlink frequency band.
- the parameter for example, transmission power in RACH
- the outline of the operation of the wireless communication system 1 regarding the inter-cell handover from the macro cell 10 to the small cell 30 in the downlink frequency band has been described above.
- the operation can be similarly applied to the inter-frequency handover to the downlink frequency band in the small cell 30.
- FIG. 6 is an explanatory diagram for explaining the outline of the operation of the wireless communication system 1 for the uplink frequency band. Referring to FIG. 6, operations of the wireless communication system 1 for the uplink frequency band are shown in (1) to (6).
- the eNB 100 instructs the UE 200a to be handed over to measure the degree of interference (hereinafter referred to as interference level) between the UE 200a and the one or more other UEs 200.
- interference level the degree of interference
- the eNB 100 instructs one or more other UEs 200 (for example, the UE 200b) that perform radio communication in the macro cell 10 to measure the interference level between the UE 200a and the one or more other UEs 200.
- Each of the one or more other UEs 200 transmits a signal for measuring an interference level (hereinafter referred to as an “interference level measurement signal”).
- the handover target UE 200a receives each interference level measurement signal, and determines the interference level between the own device in the uplink frequency band and each of the one or more other UEs 200 (for example, the UE 200b). taking measurement.
- the UE 200a to be handed over transmits an interference level measurement result to the eNB 100.
- the eNB 100 controls the transmission power of the one or more other UEs 200 (for example, the UE 200b) based on the measurement result. More specifically, for example, the eNB 100 does not generate interference from the one or more other UEs 200 (for example, the UE 200b) to the UE 200a based on the measurement result. Determine the transmission power. Then, the eNB 100 notifies the determined transmission power to the one or more other UEs 200.
- the wireless communication system 1 operates as described in (1) to (6) above, for example. Based on the measurement result, it is possible to predict how much interference may occur from one or more other UEs 200 close to the small cell 30 to the UE 200a to be handed over. And based on the said measurement result, the said interference can be suppressed by changing the transmission power of said 1 or more another UE200. For example, when it is determined from the measurement result that the interference level is high, the interference can be suppressed by reducing the transmission power of the corresponding UE 200 among the one or more other UEs 200. In this way, it is possible to suppress interference that occurs during inter-cell handover from the macro cell 10 to the small cell 30 in the uplink frequency band.
- FIG. 7 is a block diagram illustrating an example of the configuration of the eNB 100 according to the present embodiment.
- the eNB 100 includes a radio communication unit 110, a network communication unit 120, a storage unit 130, and a control unit 140.
- the radio communication unit 110 performs radio communication with the UE 200 within the macro cell 10. Further, in the macro cell 10, wireless communication using the FDD method is performed using a frequency band. In other words, the radio communication unit 110 performs radio communication with the UE 200 in the macro cell 10 by the FDD method using the frequency band. More specifically, the radio communication unit 110 transmits a signal to the UE 200 in the macro cell 10 using the downlink frequency band. Further, the radio communication unit 110 receives a signal from the UE 200 in the macro cell 10 using the uplink frequency band.
- the macro cell 10 overlaps part or all of the small cell 30. In other words, the small cell 30 partially or entirely overlaps with the macro cell.
- wireless communication by the TDD scheme is performed using the frequency band.
- the wireless communication unit 110 includes an antenna and an RF circuit, for example.
- Network communication unit 120 The network communication unit 120 communicates with other communication nodes. For example, the network communication unit 120 communicates with the HeNB 300 directly or via any communication node.
- the storage unit 130 stores a program and data for the operation of the eNB 100.
- the storage unit 130 includes a storage medium such as a hard disk or a semiconductor memory.
- Control unit 140 The control unit 140 provides various functions of the eNB 100.
- the control unit 140 corresponds to a processor such as a CPU or a DSP, and provides the various functions described above by executing a program stored in the storage unit 130 or another storage medium.
- the control unit 140 includes a measurement result acquisition unit 141 and a handover control unit 143 (hereinafter referred to as “H / O control unit 143”).
- the measurement result acquisition unit 141 is configured to perform communication between one or more other UEs 200 that perform radio communication in the macro cell 10 and the UE 200 at the time of handover of the UE 200 that enables the UE 200 to perform radio communication in the small cell 30. Obtain the measurement result of the degree of interference.
- wireless communication within the macro cell 10 is synonymous with “wireless communication with the eNB 100 of the macro cell 10”.
- the above handover is a handover that enables the UE 200 to perform wireless communication in the small cell 30 using the downlink frequency band of the macro cell 10. More specifically, for example, the handover includes an inter-cell handover of the UE 200 from the macro cell 10 to the small cell 30 in the downlink frequency band. The handover includes an inter-frequency handover of the UE 200 to the downlink frequency band of the macro cell 10 in the small cell 30.
- the measurement result acquisition unit 141 sends the UE 200a and the one or more UEs to the UE 200a to be handed over and the one or more other UEs 200 via the radio communication unit 110. Instructs measurement of interference level with another UE 200. More specifically, the measurement result acquisition unit 141 instructs the UE 200a to be handed over to transmit an interference level measurement signal.
- the interference level measurement signal is, for example, a reference signal.
- the measurement result acquisition unit 141 instructs the one or more other UEs 200 to receive the interference level measurement signal and measure the interference level.
- the measurement of the interference level is, for example, measurement of RSRP (Reference Signal Received Power). Then, when the wireless communication unit 110 receives the measurement result of the interference level from each of the one or more other UEs 200, the measurement result acquisition unit 141 acquires the measurement result.
- RSRP Reference Signal Received Power
- the handover is a handover that enables the UE 200 to perform radio communication with the small cell 30 using the uplink frequency band of the macro cell 10. More specifically, for example, the handover includes an inter-cell handover of the UE 200 from the macro cell 10 to the small cell 30 in the uplink frequency band. The handover includes an inter-frequency handover of the UE 200 to the uplink frequency band of the macro cell 10 in the small cell 30.
- the measurement result acquisition unit 141 sends the UE 200a and the one or more UEs to the UE 200a to be handed over and the one or more other UEs 200 via the radio communication unit 110. Instructs measurement of interference level with another UE 200. More specifically, the measurement result acquisition unit 141 instructs the one or more other UEs 200 to transmit an interference level measurement signal (for example, a reference signal). In addition, the measurement result acquisition unit 141 instructs the UE 200a to be handed over to receive the interference level measurement signal and measure the interference level (for example, RSRP). And if the radio
- an interference level measurement signal for example, a reference signal
- the measurement result acquisition unit 141 instructs the UE 200a to be handed over to receive the interference level measurement signal and measure the interference level (for example, RSRP).
- wireless communication part 110 receives the measurement result of interference level from UE200a
- the measurement result acquisition unit 141 acquires the measurement result.
- the measurement result acquisition unit 141 is not all of one or more other UEs 200 that perform radio communication in the macro cell 10, but the UE 200 close to the small cell 30 of the one or more other UEs 200. Instruct the measurement of the interference level.
- the UE 200 close to the small cell 30 is, for example, the UE 200 that has transmitted Proximity Indication.
- the measurement of the interference level is omitted. That is, the measurement result acquisition unit 141 does not acquire the measurement result. As an example, when there is no UE 200 that has transmitted Proximity Indication, the measurement result acquisition unit 141 does not instruct measurement of the interference level and does not acquire the measurement result.
- the UE 200 related to the measurement can be narrowed down to the UE 200 that generates the large interference or the UE 200 that is damaged by the large interference. Therefore, it is possible to reduce the load required for measurement in the wireless communication system 1 while suppressing large interference.
- the measurement of the interference level that is, the transmission and reception of the interference level measurement signal may be performed by ABS (Almost Blank Subframes).
- ABS Almost Blank Subframes
- the H / O control unit 143 controls handover of the UE 200 that enables the UE 200 to perform radio communication with the small cell 30.
- the above handover is a handover that enables the UE 200 to perform wireless communication in the small cell 30 using the downlink frequency band of the macro cell 10.
- the H / O control unit 143 controls parameters of the UE 200 that is a handover target regarding the RACH based on the measurement result.
- the parameter is, for example, the transmission power of the UE 200 in the RACH.
- the H / O control unit 143 prevents the UE 200a in the RACH from generating interference from the UE 200a to the one or more other UEs 200 (for example, the UE 200b) based on the measurement result. Determine the transmission power.
- the H / O control unit 143 when determining that the interference level is high (for example, RSRP is larger than a predetermined threshold) from the measurement result (for example, RSRP), the H / O control unit 143 further increases the transmission power of the UE 200a in the RACH. Make it smaller.
- the H / O control unit 143 maintains the transmission power of the UE 200a in the RACH when it is determined from the measurement result (for example, RSRP) that the interference level is low (for example, RSRP is equal to or less than a predetermined threshold). Then, the H / O control unit 143 notifies the UE 200a of the determined transmission power via the radio communication unit 110.
- the measurement result for example, RSRP
- RSRP the interference level is low
- the handover is a handover that enables the UE 200 to perform radio communication with the small cell 30 using the uplink frequency band of the macro cell 10.
- the H / O control unit 143 controls the transmission power of the one or more other UEs 200 in the uplink frequency band based on the measurement result.
- the H / O control unit 143 does not cause interference from the one or more other UEs 200 (for example, the UE 200b) to the UE 200a based on the measurement result.
- the transmission power of the one or more other UEs 200 in the band is determined.
- the H / O control unit 143 determines that the interference level is large (for example, RSRP is larger than a predetermined threshold) from the measurement result (for example, RSRP), the one or more other UEs 200 described above.
- the transmission power in the uplink frequency band of the corresponding UE 200 is reduced.
- the H / O control unit 143 determines that the interference level is low (for example, RSRP is equal to or lower than a predetermined threshold) from the measurement result (for example, RSRP), the H / O control unit 143 The transmission power of the corresponding UE 200 in the uplink frequency band is maintained. Then, the H / O control unit 143 notifies the determined transmission power to each of the one or more other UEs 200 via the wireless communication unit 110.
- the interference level for example, RSRP is equal to or lower than a predetermined threshold
- FIG. 8 is a block diagram illustrating an example of the configuration of the UE 200 according to the present embodiment.
- the UE 200 includes a radio communication unit 210, a storage unit 220, and a control unit 230.
- the radio communication unit 210 performs radio communication with the eNB 100 of the macro cell 10 within the macro cell 10. Further, in the macro cell 10, wireless communication using the FDD method is performed using a frequency band. In other words, the radio communication unit 210 performs radio communication with the eNB 100 of the macro cell 10 by the FDD method using the frequency band. More specifically, the radio communication unit 210 receives a signal from the eNB 100 of the macro cell 10 using the downlink frequency band. Moreover, the radio
- the wireless communication unit 210 performs wireless communication with the HeNB 300 of the small cell 30 within the small cell 30. Further, in the small cell 30, wireless communication using the TDD scheme is performed using the frequency band. In other words, the radio communication unit 210 performs radio communication with the HeNB 300 of the small cell 30 using the frequency band in the TDD scheme. More specifically, the radio communication unit 210 receives a signal from the HeNB 300 of the small cell 30 in the downlink subframe. Moreover, the radio
- the macro cell 10 overlaps part or all of the small cell 30.
- the small cell 30 partially or entirely overlaps with the macro cell.
- the storage unit 220 stores a program and data for the operation of the UE 200.
- the storage unit 220 includes a storage medium such as a hard disk or a semiconductor memory.
- Control unit 230 provides various functions of the UE 200.
- the control unit 230 corresponds to a processor such as a CPU or a DSP, and provides the various functions described above by executing a program stored in the storage unit 220 or another storage medium.
- control unit 230 enables the UE 200 to perform radio communication in the small cell 30.
- One or more other units that perform radio communication in the macro cell 10 at the time of handover of the UE 200 Control for measuring the degree of interference between the UE 200 and the UE 200 is performed.
- the above handover is a handover that enables the UE 200 to perform wireless communication in the small cell 30 using the downlink frequency band of the macro cell 10.
- the control unit 230 is instructed by the eNB 100 to measure the interference level between the UE 200 and the one or more other UEs 200 via the radio communication unit 210. Then, the control unit 230 causes the wireless communication unit 210 to transmit an interference level measurement signal (for example, a reference signal).
- an interference level measurement signal for example, a reference signal
- the handover is a handover that enables the UE 200 to perform radio communication with the small cell 30 using the uplink frequency band of the macro cell 10.
- the control unit 230 is instructed by the eNB 100 to measure the interference level between the UE 200 and the one or more other UEs 200 via the radio communication unit 210. Then, the control unit 230 causes the radio communication unit 210 to receive an interference level measurement signal (for example, a reference signal) from the one or more other UEs 200, and from the interference level measurement signal, the interference level (for example, RSRP) is measured.
- an interference level measurement signal for example, a reference signal
- the interference level for example, RSRP
- the control unit 230 performs control for measuring the degree of interference between the UE 200 and the other UE 200 at the time of handover.
- the above handover is a handover that enables another UE 200 to perform radio communication in the small cell 30 using the downlink frequency band of the macro cell 10.
- the control unit 230 is instructed by the eNB 100 to measure the interference level between the UE 200 and the other UE 200 via the radio communication unit 210.
- the control unit 230 causes the radio communication unit 210 to receive an interference level measurement signal (for example, a reference signal) from the other UE 200 and measure an interference level (for example, RSRP) from the interference level measurement signal.
- an interference level measurement signal for example, a reference signal
- an interference level for example, RSRP
- the handover is a handover that allows another UE 200 to perform radio communication with the small cell 30 using the uplink frequency band of the macro cell 10.
- the control unit 230 is instructed by the eNB 100 to measure the interference level between the UE 200 and the other UE 200 via the radio communication unit 210. Then, the control unit 230 causes the wireless communication unit 210 to transmit an interference level measurement signal (for example, a reference signal).
- the control unit 230 performs handover of the UE 200 that enables the UE 200 to perform radio communication in the small cell 30 using the downlink frequency band.
- UE200 parameters for RACH are set.
- the parameter is, for example, the transmission power of the UE 200 in the RACH.
- -Control of transmission power of UE 200 in uplink frequency band For example, when UE 200 is performing radio communication in macro cell 10, another UE 200 performs radio communication in small cell 30 using the uplink frequency band. The handover of the other UE 200 that enables it may be performed. In this case, the control unit 230 sets the transmission power of the UE 200 in the uplink frequency band according to the control of the eNB 100 at the time of handover.
- case A shows a case where measurement of the interference level is omitted.
- Case B indicates a case where a handover is executed that allows the UE 200 to perform radio communication in the small cell 30 using the downlink frequency band.
- Case C shows a case where a handover is executed that allows the UE 200 to perform radio communication in the small cell 30 using the uplink frequency band.
- FIG. 9 is a sequence diagram illustrating an example of a schematic flow of communication control processing according to the present embodiment in a case where measurement of the interference level is omitted. This example can also be said to be an example of a schematic flow of processing in the conventional handover.
- the UE 200 measures RSSP and / or RSSQ (Reference Signal Received Quality) for the eNB 100, the HeNB 300, and other neighboring cells. For example, the measurement is obtained by averaging RSSP and / or RSSQ with respect to time based on a plurality of reference signal reception results. And UE200 transmits a measurement result to eNB100 by step S503.
- RSSP and / or RSSQ Reference Signal Received Quality
- step S505 the eNB 100, the HeNB 300, and the MME (Mobility Management Entity) on the eNB 100 side determine whether the handover should be executed based on the measurement result.
- the eNB 100, the HeNB 300, and the MME (Mobility Management Entity) on the eNB 100 side determine whether the handover should be executed based on the measurement result.
- step S507 the eNB 100 transmits a handover request message to the MME on the eNB 100 side.
- the MME on the eNB 100 side transmits a relocation transfer request message to the MME on the HeNB 300 side.
- step S511 the MME on the HeNB 300 side transmits a handover request message to the HeNB 300.
- Step S513 the MME on the HeNB 300 side transmits a relocation transfer response message to the MME on the eNB 100 side.
- step S515 the MME on the eNB 100 side instructs the eNB 100 to perform handover.
- step S517 the eNB 100 instructs the UE 200 to perform handover.
- step S519 the UE 200 transmits a random access preamble signal on the RACH.
- FIG. 10 shows an example of a schematic flow of a communication control process according to the present embodiment in a case where a handover that allows the UE 200 to perform radio communication in the small cell 30 using the downlink frequency band is executed. It is a sequence diagram. Here, only steps S531 to S539, which are differences between the case B example and the case A example, will be described.
- step S531 the eNB 100 (measurement result acquisition unit 141) instructs the UE 200 that is a handover target to measure the interference level between the UE 200 and one or more other UEs 200 that perform radio communication in the macro cell 10. More specifically, for example, the eNB 100 instructs the UE 200 that is a handover target to transmit an interference level measurement signal (for example, a reference signal).
- an interference level measurement signal for example, a reference signal
- the eNB 100 instructs the one or more other UEs 200 to measure the interference level between the one or more other UEs 200 and the handover target UE 200. . More specifically, for example, the eNB 100 instructs the one or more other UEs 200 to receive the interference level measurement signal and measure the interference level (for example, RSRP).
- the interference level measurement signal for example, RSRP
- step S535 the handover target UE 200 transmits an interference level measurement signal to the one or more other UEs 200.
- Each of the one or more other UEs 200 receives the interference level measurement signal and measures the interference level.
- step S537 each of the one or more other UEs 200 transmits a measurement result to the eNB 100.
- the eNB 100 controls the parameters of the UE 200 to be handed over regarding the RACH based on the measurement result. More specifically, for example, the eNB 100 controls the transmission power of the UE 200 that is a handover target in the RACH. Note that this control may be executed together with the handover instruction in step S517. Moreover, the said control may not be performed directly from eNB100, but may be performed indirectly via HeNB300.
- FIG. 11 shows an example of a schematic flow of a communication control process according to the present embodiment in a case where a handover that allows the UE 200 to perform radio communication in the small cell 30 using the uplink frequency band is executed. It is a sequence diagram. Here, only steps S541 to 549, which are differences between the case C and the case A, will be described.
- step S541 the eNB 100 (measurement result acquisition unit 141) instructs the UE 200 that is a handover target to measure the interference level between the UE 200 and one or more other UEs 200 that perform radio communication within the macro cell 10. More specifically, the eNB 100 instructs the UE 200 to be handed over to receive the interference level measurement signal and measure the interference level (for example, RSRP).
- the interference level for example, RSRP
- step S543 the eNB 100 (measurement result acquisition unit 141) instructs the one or more other UEs 200 to measure the interference level between the one or more other UEs 200 and the handover target UE 200. . More specifically, the eNB 100 instructs the one or more other UEs 200 to transmit an interference level measurement signal (for example, a reference signal).
- an interference level measurement signal for example, a reference signal
- each of the one or more other UEs 200 transmits an interference level measurement signal to the handover target UE 200.
- each of the one or more other UEs 200 transmits an interference level measurement signal at different times.
- the handover target UE 200 receives the interference level measurement signal from each of the one or more other UEs 200 and measures the interference level.
- the handover target UE 200 transmits the measurement result to the eNB 100.
- step S549 the eNB 100 (H / O control unit 143) controls the transmission power of the one or more other UEs 200 in the uplink frequency band based on the measurement result.
- FIG. 12 is an explanatory diagram for explaining the outline of the operation of the wireless communication system 1 according to the modification example regarding the downlink frequency band and the uplink frequency band. Referring to FIG. 12, operations of the wireless communication system 1 for the downlink frequency band and the uplink frequency band are shown in (1) to (9).
- the eNB 100 instructs the UE 200a to be handed over to measure the interference level between the UE 200a and the one or more other UEs 200.
- the eNB 100 instructs one or more other UEs 200 (for example, the UE 200b) that perform radio communication in the macro cell 10 to measure the interference level between the UE 200a and the one or more other UEs 200.
- the UE 200a to be handed over transmits an interference level measurement signal in the downlink frequency band.
- Each of the one or more other UEs 200 receives the interference level measurement signal in the downlink frequency band, and determines the interference level between the UE 200a and the own apparatus in the downlink frequency band. taking measurement.
- Each of the one or more other UEs 200 (for example, the UE 200b) transmits an interference level measurement result to the eNB 100.
- Each of the one or more other UEs 200 (for example, the UE 200b) transmits an interference level measurement signal in the uplink frequency band.
- the handover target UE 200a receives the interference level measurement signal in the uplink frequency band, and between the UE 200a in the uplink frequency band and each of the one or more other UEs 200 (for example, UE 200b). Measure the interference level.
- the UE 200a to be handed over transmits an interference level measurement result to the eNB 100.
- the eNB 100 determines whether to execute handover based on the measurement result. There are various variations in determining whether to execute a handover.
- the handover is an inter-cell handover of the UE 200 from the macro cell 10 to the small cell 30. Then, the eNB 100 determines whether or not to execute the handover in the downlink frequency band of the macro cell 10 and / or determines whether or not to execute the handover in the uplink frequency band of the macro cell 10. Then, at least one of the handover in the downlink frequency band of the macro cell 10 and the handover in the uplink frequency band of the macro cell 10 is executed.
- the large interference can be avoided by not performing the handover in the frequency band in which large interference is expected to occur. For example, when large interference is predicted to occur in the downlink frequency band, handover in the uplink frequency band is executed. As a result, large interference in the downlink frequency band can be avoided. Similarly, when large interference is predicted to occur in the uplink frequency band, handover in the downlink frequency band is executed. As a result, large interference in the uplink frequency band can be avoided. In addition, since at least one of the downlink frequency band and the uplink frequency band is executed, it is possible to avoid a situation in which the UE 200 cannot completely perform wireless communication. Further, in a frequency band where handover is not executed, it is possible to avoid the UE 200 communicating with the eNB 100 of the macro cell 10 in the small cell 30 by stopping the radio communication.
- the handover is an inter-frequency handover of the UE 200 in the small cell 30. Then, the eNB 100 determines whether or not to execute the inter-frequency handover based on the measurement result.
- the large interference can be avoided by not performing inter-frequency handover. Further, unlike inter-cell handover, even if inter-frequency handover is not executed, UE 200 can continue radio communication at least in small cell 30, and UE 200 may not be able to completely perform radio communication. Absent.
- the macro cell 10 and the small cell 30 use a plurality of frequency bands (for example, a plurality of component carriers).
- the eNB 100 determines whether or not to execute handover for each of the plurality of frequency bands.
- the handover may be an inter-cell handover or an inter-frequency handover.
- the large interference can be avoided by not performing the handover for the frequency band in which large interference is predicted to occur. For example, handover is executed only for a frequency band that is predicted not to cause large interference among a plurality of frequency bands. As a result, large interference can be avoided.
- a handover that is not executed can be limited to only a handover that actually causes interference.
- the interference level is measured in both the downlink frequency band and the uplink frequency band.
- the interference level may be measured only in one of the downlink frequency band and the uplink frequency band depending on the contents of execution of the handover.
- the H / O control unit 143 determines whether or not to execute a handover of the UE 200 that enables the UE 200 to perform radio communication with the small cell 30.
- the handover is an inter-cell handover of the UE 200 from the macro cell 10 to the small cell 30. Then, the H / O control unit 143 determines whether or not to execute the handover in the downlink frequency band of the macro cell 10 and / or determines whether or not to execute the handover in the uplink frequency band of the macro cell 10. To decide. Then, at least one of the handover in the downlink frequency band of the macro cell 10 and the handover in the uplink frequency band of the macro cell 10 is executed.
- the handover may be executed in a frequency band with smaller interference between the downlink frequency band and the uplink frequency band. In this case, if the interference level of both frequency bands is small, handover may be executed in both frequency bands. Alternatively, it may be determined whether handover is performed in the downlink frequency band and whether handover is performed in the uplink frequency band. Alternatively, it may be determined whether handover is performed in the uplink frequency band and whether handover is performed in the downlink frequency band.
- the handover may be an inter-frequency handover of the UE 200 in the small cell 30. That is, the H / O control unit 143 may determine whether to execute the inter-frequency handover of the UE 200 in the small cell 30 based on the measurement result.
- the H / O control unit 143 further determines whether to execute a handover of the macro cell 10 to the downlink frequency band or a handover of the macro cell 10 to the uplink frequency band. Good. According to such a determination, it is possible to further reduce interference associated with inter-frequency handover.
- the macro cell 10 and the small cell 30 use a plurality of frequency bands (for example, a plurality of component carriers). May be. Then, the H / O control unit 143 may determine whether or not to execute handover for each frequency band among the plurality of frequency bands. In this case, the measurement result acquisition unit 141 acquires interference level measurement results in the plurality of frequency bands at the time of the handover.
- the handover may be an inter-cell handover of the UE 200 from the macro cell 10 to the small cell 30. Then, it may be determined whether or not to execute the handover in the individual frequency bands. By such determination, the large interference can be avoided by not performing the inter-cell handover in the frequency band in which large interference is predicted to occur. For example, handover is performed in a frequency band that is predicted not to cause large interference among a plurality of frequency bands. As a result, large interference can be avoided.
- the handover may be an inter-frequency handover of the UE 200 in the small cell 30.
- the H / O control unit 143 may determine which of the plurality of frequency bands is to be subjected to the inter-frequency handover. With such a determination, large interference can be avoided by performing inter-frequency handover to a frequency band where smaller interference is expected to occur.
- the H / O control unit 143 may control the parameters of the UE 200 related to the RACH or the transmission power of the UE 200 in the uplink frequency band based on the measurement result as in the above-described embodiment. It may or may not be controlled.
- FIG. 13 is a sequence diagram illustrating an example of a schematic flow of a communication control process according to a modification of the present embodiment.
- Steps S561 to S573 which are differences between the example of the present embodiment described with reference to FIG. 9 and the example of the modification of the present embodiment, will be described.
- step S561 the eNB 100 (measurement result acquisition unit 141) instructs the UE 200 that is a handover target to measure the interference level between the UE 200 and one or more other UEs 200 that perform radio communication in the macro cell 10.
- step S563 the eNB 100 (measurement result acquisition unit 141) instructs the one or more other UEs 200 to measure the interference level between the one or more other UEs 200 and the handover target UE 200. .
- step S565 the handover target UE 200 transmits an interference level measurement signal to the one or more other UEs 200 in the downlink frequency band.
- Each of the one or more other UEs 200 receives the interference level measurement signal and measures the interference level.
- step S567 each of the one or more other UEs 200 transmits a measurement result to the eNB 100.
- each of the one or more other UEs 200 transmits an interference level measurement signal to the handover target UE 200.
- each of the one or more other UEs 200 transmits an interference level measurement signal at different times.
- the handover target UE 200 receives the interference level measurement signal from each of the one or more other UEs 200 and measures the interference level.
- the handover target UE 200 transmits the measurement result to the eNB 100.
- the eNB 100 determines whether or not to perform handover of the UE 200 that is a handover target, based on the measurement result.
- the above measurement result makes it possible to predict how much interference may occur from one UE 200a to be handed over to one or more other UEs 200 close to the small cell 30, so that handover can be performed based on the measurement result. If this is controlled, interference can be suppressed. That is, it becomes possible to suppress interference at the time of handover in a heterogeneous network.
- the handover is a handover that enables the UE 200 to perform radio communication with the small cell 30 using the downlink frequency band of the macro cell 10. And based on the said measurement result, the parameter of UE200 regarding RACH is controlled.
- the parameter is the transmission power of the UE 200 in the RACH.
- the interference can be suppressed by changing a parameter (for example, transmission power in the RACH) of the UE 200a regarding the RACH. For example, when it is determined from the measurement result that the interference level is high, the interference can be suppressed by reducing the transmission power of the UE 200a in the RACH. In this way, it is possible to suppress interference that occurs during inter-cell handover from the macro cell 10 to the small cell 30 in the downlink frequency band. In addition, it is possible to suppress interference that occurs during inter-frequency handover to the downlink frequency in the small cell 30.
- a parameter for example, transmission power in the RACH
- the handover is a handover that enables the UE 200 to perform radio communication with the small cell 30 using the uplink frequency band of the macro cell 10. Based on the measurement result, the transmission power of the one or more other UEs 200 in the uplink frequency band is controlled.
- the interference can be suppressed by changing the transmission power of the one or more other UEs 200. For example, when it is determined from the measurement result that the interference level is high, the interference can be suppressed by reducing the transmission power of the corresponding UE 200 among the one or more other UEs 200. In this way, it is possible to suppress interference that occurs during inter-cell handover from the macro cell 10 to the small cell 30 in the uplink frequency band. In addition, it is possible to suppress interference that occurs during inter-frequency handover to the uplink frequency in the small cell 30.
- the large interference can be avoided by not performing the handover for the frequency band in which large interference is predicted to occur.
- the small cell in the present disclosure may be a cell such as a pico cell, a femto cell, a nano cell, or a micro cell.
- a small cell is any complementary cell that can increase the communication capacity of a macro cell.
- the wireless communication system according to the above embodiment is a wireless communication system compliant with LTE or LTE-Advanced, but the present technology is not limited to this example.
- the presupposed wireless communication system may be a wireless communication system similar to LTE or LTE-Advanced, or a wireless communication system compliant with a standard further developed from LTE or LTE-Advanced.
- the communication control apparatus that controls handover is LTE or LTE-Advanced eNodeB, but the present technology is not limited to this example.
- the communication control device may be a base station that complies with another communication standard, or may be a device that constitutes a part of the base station.
- the communication control device may be another device that controls the base station.
- the communication control apparatus may not include a wireless communication unit.
- the terminal device that communicates in the cell is an LTE or LTE-Advanced UE, but the present technology is not limited to this example.
- the terminal device may be a terminal device that complies with another communication standard.
- processing steps in the communication control processing of this specification do not necessarily have to be executed in time series in the order described in the flowchart.
- the processing steps in the communication control process may be executed in an order different from the order described in the flowchart, or may be executed in parallel.
- a storage medium storing the computer program is also provided.
- a wireless communication unit that wirelessly communicates with the device; The degree of interference between the terminal device and one or more other terminal devices that perform wireless communication in the macro cell during handover of the terminal device that enables the terminal device to perform wireless communication in the small cell
- a communication control device comprising: (2) The communication control apparatus according to (1), wherein the handover is a handover that enables the terminal apparatus to perform radio communication in the small cell using a downlink frequency band of the macro cell.
- the said control part is a communication control apparatus as described in said (2) which controls the parameter of the said terminal device regarding a random access channel based on the said measurement result.
- the communication control device (4) The communication control device according to (3), wherein the parameter is transmission power of the terminal device in the random access channel. (5) The communication control device according to any one of (3) and (4), wherein the handover includes an inter-cell handover of the terminal device from the macro cell to the small cell in the downlink frequency band. (6) The communication control device according to any one of (3) to (5), wherein the handover includes an inter-frequency handover of the terminal device to the downlink frequency band of the macro cell in the small cell. (7) The communication control apparatus according to (1), wherein the handover is a handover that enables the terminal apparatus to perform radio communication in the small cell using an uplink frequency band of the macro cell.
- the communication control device controls transmission power of the one or more other terminal devices in the uplink frequency band based on the measurement result.
- the handover includes an inter-cell handover of the terminal device from the macro cell to the small cell in the uplink frequency band.
- the communication control device includes an inter-frequency handover of the terminal device to the uplink frequency band of the macro cell in the small cell.
- the control unit determines whether or not to execute the handover based on the measurement result.
- the handover is an inter-cell handover of the terminal device from the macro cell to the small cell
- the control unit determines whether to execute the handover in the downlink frequency band of the macro cell based on the measurement result, or determines whether to execute the handover in the uplink frequency band of the macro cell. Decide At least one of the handover in the downlink frequency band of the macro cell and the handover in the uplink frequency band of the macro cell is performed;
- the communication control device according to (11).
- (13) The communication control device according to (11), wherein the handover is an inter-frequency handover of the terminal device in the small cell.
- the communication control apparatus determines which of the handover to the downlink frequency band of the macro cell and the handover to the uplink frequency band of the macro cell is to be executed. .
- the control unit determines which of the handover to the downlink frequency band of the macro cell and the handover to the uplink frequency band of the macro cell is to be executed. .
- a plurality of frequency bands are used, The acquisition unit acquires the measurement result of the degree of interference in the plurality of frequency bands during the handover, The control unit determines whether to execute the handover for each frequency band of the plurality of frequency bands based on the measurement result.
- the communication control device according to (11).
- the handover is an inter-cell handover of the terminal device from the macro cell to the small cell, The controller determines whether to perform the handover in the individual frequency bands; The communication control device according to (15).
- the handover is an inter-frequency handover of the terminal device in the small cell
- the control unit determines which frequency band of the plurality of frequency bands to perform the handover.
- the communication control device according to (15).
- (18) A macro cell in which radio communication in the FDD scheme is performed using a frequency band, and the terminal overlaps with a part or the whole of a small cell in which radio communication in the TDD scheme is performed using the frequency band.
- the degree of interference between the terminal device and one or more other terminal devices that perform wireless communication in the macro cell during handover of the terminal device that enables the terminal device to perform wireless communication in the small cell Obtaining measurement results for Controlling the handover based on the measurement result; Including a communication control method.
- a small cell that partially or entirely overlaps with a macro cell in which radio communication in the FDD scheme is performed using the frequency band, and in which the terminal performs radio communication in the TDD scheme using the frequency band A measurement result of the degree of interference between the terminal device and one or more other terminal devices wirelessly communicating in the macro cell at the time of handover of the terminal device, which enables the device to perform wireless communication;
- a communication control device comprising: (20) A macro cell in which radio communication in the FDD scheme is performed using a frequency band, and in the macro cell overlapping with a part or the whole of a small cell in which radio communication in the TDD scheme is performed using the frequency band, A wireless communication unit that wirelessly communicates with a base station of a macro cell and wirelessly communicates with the base station of the small cell within the small cell; Measurement of the degree of interference between one or more other terminal devices that communicate wirelessly in the macro cell and the own device at the time of handover of
- wireless communication system 10 macro cell 30 small cell 100 eNodeB / eNB DESCRIPTION OF SYMBOLS 110 Wireless communication part 120 Network communication part 130 Storage part 140 Control part 141 Measurement result acquisition part 143 Handover control part / HO control part 200 UE (User Equipment) 210 wireless communication unit 220 storage unit 230 control unit 300 Home eNodeB / HeNB
Abstract
Description
1.はじめに
1.1.LTEにおけるFDD及びTDD
1.2.想定されるヘテロジニアスネットワーク
1.3.ヘテロジニアスネットワークにおける干渉
1.4.技術的課題
2.無線通信システムの概略的な構成
3.本実施形態の概要
4.各装置の構成
4.1.eNodeBの構成
4.2.UEの構成
5.処理の流れ
6.変形例
6.1.概要
6.2.eNodeBの構成
6.3.UEの構成
6.4.処理の流れ
7.まとめ
まず、図1~図3を参照して、LTEにおけるFDD及びTDD、想定されるヘテロジニアスネットワーク、ヘテロジニアスネットワークにおける干渉、及び技術的課題を説明する。
まず、本実施形態の説明の前提となる、LTEにおけるFDD(Frequency Division Duplex)及びTDD(Time Division Duplex)を説明する。
次に、図1を参照して、本実施形態の説明の前提となる、想定されるヘテロジニアスネットワークを説明する。
次に、図2及び図3を参照して、上述した想定されるHetNetにおける干渉を説明する。
次に、上記想定されるHetNetについての技術的課題を説明する。
まず、上記想定されるHetNetにおけるセル間ハンドオーバの際の干渉を説明する。上記想定されるHetNetでは、とりわけ、マクロセルからスモールセルへのセル間ハンドオーバの際の干渉が問題になる。以下、当該ハンドオーバの際の干渉について具体的に説明する。
まず、ダウンリンク周波数帯域における上記ハンドオーバの際には、ハンドオーバの対象のUEから、マクロセル内のUEのうちスモールセルに近いUEへの信号送信が、干渉を発生させ得る。
また、アップリンク周波数帯域における上記ハンドオーバの際には、マクロセル内のUEのうちスモールセルに近いUEから、ハンドオーバの対象のUEへの信号送信が、干渉を発生させ得る。
次に、上記想定されるHetNetにおける周波数間ハンドオーバの際の干渉を説明する。上記想定されるHetNetでは、とりわけ、スモールセルにおける周波数間ハンドオーバの際の干渉が問題になる。以下、当該ハンドオーバの際の干渉について具体的に説明する。
まず、ダウンリンク周波数帯域への上記ハンドオーバの際には、ハンドオーバの対象のUEから、マクロセル内のUEのうちスモールセルに近いUEへの信号送信が、干渉を発生させ得る。具体的な干渉は、ダウンリンク周波数帯域におけるマクロセルからスモールセルへのセル間ハンドオーバについての干渉と同様である。即ち、スモールセルにおけるダウンリンク周波数へのハンドオーバでは、ダウンリンク周波数帯域でランダムアクセスが行われるので、上記セル間ハンドオーバと同様の干渉が発生し得る。
また、アップリンク周波数帯域への上記ハンドオーバの際には、マクロセル内のUEのうちスモールセルに近いUEから、ハンドオーバの対象のUEへの信号送信が、干渉を発生させ得る。具体的な干渉は、アップリンク周波数帯域におけるマクロセルからスモールセルへのセル間ハンドオーバについての干渉と同様である。即ち、スモールセルにおけるアップリンク周波数へのハンドオーバでは、当該ハンドオーバ後に、マクロセル10で無線通信するUE21がスモールセル30の近傍に存在すると、当該UE21からハンドオーバの対象となったUE21への信号送信による干渉が発生し得る。
図4を参照して、本開示の実施形態に係る無線通信システムの概略的な構成を説明する。図4は、本実施形態に係る無線通信システム1の概略的な構成の一例を示す説明図である。図4を参照すると、無線通信システム1は、マクロセル10のeNB100、UE200、及びスモールセル30のHeNB300を含む。UE200aは、ハンドオーバの対象となるUEであり、UE200bは、マクロセル10(より厳密には、マクロセル10のうちのスモールセル30を除いた領域)内で無線通信するUEである。
次に、図5及び図6を参照して、本実施形態の概要を説明する。本実施形態では、UE200aがスモールセル30で無線通信することを可能にする当該UE200aのハンドオーバの際に、マクロセル10内で無線通信する1つ以上の別のUE200(例えば、UE200b)とUE200aとの間における干渉の度合いが測定される。そして、eNB100は、当該干渉の測定結果に基づいて、上記ハンドオーバを実行する。なお、UE200aがスモールセル30で無線通信することを可能にする当該UE200aのハンドオーバとは、マクロセル10からスモールセル30へのセル間ハンドオーバ、又はスモールセル30内での周波数間ハンドオーバである。以下、このような本実施形態の概要を、マクロセル10からスモールセル30へのセル間ハンドオーバの例を挙げて説明する。
まず、図5を参照して、ダウンリンク周波数帯域におけるマクロセル10からスモールセル30へのセル間ハンドオーバについての無線通信システム1の動作の概要を説明する。図5は、ダウンリンク周波数帯域についての無線通信システム1の動作の概要を説明するための説明図である。図5を参照すると、ダウンリンク周波数帯域についての無線通信システム1の動作が、(1)~(7)で示されている。
次に、図6を参照して、アップリンク周波数帯域におけるマクロセル10からスモールセル30へのセル間ハンドオーバについての無線通信システム1の動作の概要を説明する。図6は、アップリンク周波数帯域についての無線通信システム1の動作の概要を説明するための説明図である。図6を参照すると、アップリンク周波数帯域についての無線通信システム1の動作が、(1)~(6)で示されている。
図7及び図8を参照して、eNodeB100及びUE200の構成を説明する。
図7を参照して、本実施形態に係るeNB100の構成の一例を説明する。図7は、本実施形態に係るeNB100の構成の一例を示すブロック図である。図7を参照すると、eNB100は、無線通信部110、ネットワーク通信部120、記憶部130及び制御部140を備える。
無線通信部110は、マクロセル10内で、UE200と無線通信する。また、マクロセル10では、周波数帯域を用いてFDD方式での無線通信が行われる。換言すると、無線通信部110は、周波数帯域を用いて、FDD方式で、マクロセル10内のUE200と無線通信する。より具体的には、無線通信部110は、ダウンリンク周波数帯域を用いて、マクロセル10内のUE200への信号を送信する。また、無線通信部110は、アップリンク周波数帯域を用いて、マクロセル10内のUE200からの信号を受信する。
ネットワーク通信部120は、他の通信ノードと通信する。例えば、ネットワーク通信部120は、直接的に又はいずれかの通信ノードを介してHeNB300と通信する。
記憶部130は、eNB100の動作のためのプログラム及びデータを記憶する。記憶部130は、例えばハードディスク又は半導体メモリ等の記憶媒体を含む。
制御部140は、eNB100の様々な機能を提供する。例えば、制御部140は、CPU又はDSP等のプロセッサに相当し、記憶部130又は他の記憶媒体に記憶されるプログラムを実行することにより、上記様々な機能を提供する。制御部140は、測定結果取得部141及びハンドオーバ制御部143(以下、「H/O制御部143」と呼ぶ)を含む。
測定結果取得部141は、UE200がスモールセル30で無線通信することを可能にする当該UE200のハンドオーバの際に、マクロセル10内で無線通信する1つ以上の別のUE200と上記UE200との間における干渉の度合いの測定結果を取得する。ここでの「マクロセル10内で無線通信する」とは、「マクロセル10のeNB100と無線通信する」と同義である。
H/O制御部143は、測定結果取得部141により取得された測定結果に基づいて、UE200がスモールセル30で無線通信することを可能にする当該UE200のハンドオーバを制御する。
図8を参照して、本実施形態に係るUE200の構成の一例を説明する。図8は、本実施形態に係るUE200の構成の一例を示すブロック図である。図8を参照すると、UE200は、無線通信部210、記憶部220及び制御部230を備える。
無線通信部210は、マクロセル10内で、マクロセル10のeNB100と無線通信する。また、マクロセル10では、周波数帯域を用いてFDD方式での無線通信が行われる。換言すると、無線通信部210は、周波数帯域を用いて、FDD方式で、マクロセル10のeNB100と無線通信する。より具体的には、無線通信部210は、ダウンリンク周波数帯域を用いて、マクロセル10のeNB100からの信号を受信する。また、無線通信部210は、アップリンク周波数帯域を用いて、マクロセル10のeNB100への信号を送信する。
記憶部220は、UE200の動作のためのプログラム及びデータを記憶する。記憶部220は、例えばハードディスク又は半導体メモリ等の記憶媒体を含む。
制御部230は、UE200の様々な機能を提供する。例えば、制御部230は、CPU又はDSP等のプロセッサに相当し、記憶部220又は他の記憶媒体に記憶されるプログラムを実行することにより、上記様々な機能を提供する。
例えば、制御部230は、UE200がスモールセル30で無線通信することを可能にする当該UE200のハンドオーバの際に、マクロセル10内で無線通信する1つ以上の別のUE200と上記UE200との間における干渉の度合いの測定のための制御を行う。
また、例えば、UE200がマクロセル10内で無線通信している際に、別のUE200がスモールセル30で無線通信することを可能にする当該別のUE200のハンドオーバが、実行され得る。この場合に、制御部230は、ハンドオーバの際に、UE200と上記別のUE200との間における干渉の度合いの測定のための制御を行う。
また、制御部230は、UE200がダウンリンク周波数帯域を用いてスモールセル30で無線通信することを可能にする当該UE200のハンドオーバの際に、eNB100の制御に応じて、RACHに関するUE200のパラメータを設定する。当該パラメータは、例えば、RACHにおけるUE200の送信電力である。
また、例えば、UE200がマクロセル10内で無線通信している際に、別のUE200がアップリンク周波数帯域を用いてスモールセル30で無線通信することを可能にする当該別のUE200のハンドオーバが、実行され得る。この場合に、制御部230は、ハンドオーバの際に、eNB100の制御に応じて、上記アップリンク周波数帯域におけるUE200の送信電力を設定する。
次に、図9~図11を参照して、本実施形態に係る通信制御処理の例を説明する。以下では、ケースA、ケースB、及びケースCにおける通信制御処理の例をそれぞれ説明する。ここで、ケースAは、干渉レベルの測定が省略されるケースを示す。また、ケースBは、UE200がダウンリンク周波数帯域を用いてスモールセル30で無線通信することを可能にするハンドオーバが実行されるケースを示す。また、ケースCは、UE200がアップリンク周波数帯域を用いてスモールセル30で無線通信することを可能にするハンドオーバが実行されるケースを示す。
図9は、干渉レベルの測定が省略されるケースでの本実施形態に係る通信制御処理の概略的な流れの一例を示すシーケンス図である。当該例は、従来のハンドオーバの際の処理の概略的な流れの一例と言うこともできる。
図10は、UE200がダウンリンク周波数帯域を用いてスモールセル30で無線通信することを可能にするハンドオーバが実行されるケースでの本実施形態に係る通信制御処理の概略的な流れの一例を示すシーケンス図である。ここでは、ケースBの当該例とケースAの例との差分であるステップS531~539のみを説明する。
図11は、UE200がアップリンク周波数帯域を用いてスモールセル30で無線通信することを可能にするハンドオーバが実行されるケースでの本実施形態に係る通信制御処理の概略的な流れの一例を示すシーケンス図である。ここでは、ケースCの当該例とケースAの例との差分であるステップS541~549のみを説明する。
次に、図12及び図13を参照して、本実施形態の変形例を説明する。上述した実施形態では、干渉レベルの測定結果によらずハンドオーバが実行されたが、本変形例では、測定結果に基づいて、ハンドオーバを実行するか否かが決定される。
まず、図12を参照して、本実施形態の変形例の概要を説明する。図12は、ダウンリンク周波数帯域及びアップリンク周波数帯域についての変形例に係る無線通信システム1の動作の概要を説明するための説明図である。図12を参照すると、ダウンリンク周波数帯域及びアップリンク周波数帯域についての無線通信システム1の動作が、(1)~(9)で示されている。
第1の例では、上記ハンドオーバは、マクロセル10からスモールセル30へのUE200のセル間ハンドオーバである。そして、eNB100は、マクロセル10のダウンリンク周波数帯域における上記ハンドオーバを実行するか否かを決定し、及び/又は、マクロセル10のアップリンク周波数帯域における上記ハンドオーバを実行するか否かを決定する。そして、マクロセル10のダウンリンク周波数帯域における上記ハンドオーバ及びマクロセル10のアップリンク周波数帯域における上記ハンドオーバのうちの少なくとも一方は、実行される。
第2の例では、上記ハンドオーバは、スモールセル30におけるUE200の周波数間ハンドオーバである。そして、eNB100は、測定結果に基づいて、当該周波数間ハンドオーバを実行するか否かを決定する。
第3の例では、マクロセル10及びスモールセル30では、複数の周波数帯域(例えば、複数のコンポーネントキャリア)が用いられる。eNB100は、上記複数の周波数帯域のうちの個々の周波数帯域について、ハンドオーバを実行するか否かを決定する。当該ハンドオーバは、セル間ハンドオーバであってもよく、周波数間ハンドオーバでもよい。
以下、本実施形態の変形例に係るeNB100の構成を説明する。ここでは、上述した本実施形態のeNB100の構成に追加される技術的な特徴を説明する。
H/O制御部143は、上記測定結果に基づいて、上記UE200がスモールセル30で無線通信することを可能にするUE200のハンドオーバを実行するか否かを決定する。
ハンドオーバの実行の上記第1の例のように、例えば、上記ハンドオーバは、マクロセル10からスモールセル30へのUE200のセル間ハンドオーバである。そして、H/O制御部143は、マクロセル10のダウンリンク周波数帯域における上記ハンドオーバを実行するか否かを決定し、及び/又は、マクロセル10のアップリンク周波数帯域における上記ハンドオーバを実行するか否かを決定する。そして、マクロセル10のダウンリンク周波数帯域における上記ハンドオーバ及びマクロセル10のアップリンク周波数帯域における上記ハンドオーバのうちの少なくとも一方は、実行される。
なお、ハンドオーバの実行の上記第2の例のように、上記ハンドオーバは、スモールセル30におけるUE200の周波数間ハンドオーバであってもよい。即ち、H/O制御部143は、上記測定結果に基づいて、スモールセル30におけるUE200の周波数間ハンドオーバを実行するか否かを決定してもよい。
また、ハンドオーバの実行の上記第3の例のように、例えば、マクロセル10及びスモールセル30では、複数の周波数帯域(例えば、複数のコンポーネントキャリア)が用いられてもよい。そして、H/O制御部143は、上記複数の周波数帯域のうちの個々の周波数帯域について、ハンドオーバを実行するか否かを決定してもよい。なお、この場合には、測定結果取得部141は、上記ハンドオーバの際に、上記複数の周波数帯域における干渉レベルの測定結果を取得する。
次に、図13を参照して、本実施形態の変形例に係る通信制御処理の例を説明する。図13は、本実施形態の変形例に係る通信制御処理の概略的な流れの一例を示すシーケンス図である。ここでは、図9を参照して説明した本実施形態のケースAでの例と、本実施形態の変形例の例との差分である、ステップS561~573のみを説明する。
ここまで、図1~図13を用いて、本開示の実施形態に係る各装置及び通信制御処理を説明した。本実施形態によれば、UE200がスモールセル30で無線通信することを可能にするUE200のハンドオーバの際に、マクロセル10内で無線通信する1つ以上の別のUE200と上記UE200との間における干渉の度合いの測定結果が取得される。そして、上記測定結果に基づいて、上記ハンドオーバが制御される。
(1)
周波数帯域を用いてFDD方式での無線通信が行われるマクロセルであって、前記周波数帯域を用いてTDD方式での無線通信が行われるスモールセルの一部又は全体と重複する当該マクロセル内で、端末装置と無線通信する無線通信部と、
端末装置が前記スモールセルで無線通信することを可能にする当該端末装置のハンドオーバの際に、前記マクロセル内で無線通信する1つ以上の別の端末装置と前記端末装置との間における干渉の度合いの測定結果を取得する取得部と、
前記測定結果に基づいて、前記ハンドオーバを制御する制御部と、
を備える通信制御装置。
(2)
前記ハンドオーバは、前記端末装置が前記マクロセルのダウンリンク周波数帯域を用いて前記スモールセルで無線通信することを可能にするハンドオーバである、前記(1)に記載の通信制御装置。
(3)
前記制御部は、前記測定結果に基づいて、ランダムアクセスチャネルに関する前記端末装置のパラメータを制御する、前記(2)に記載の通信制御装置。
(4)
前記パラメータは、前記ランダムアクセスチャネルにおける前記端末装置の送信電力である、前記(3)に記載の通信制御装置。
(5)
前記ハンドオーバは、前記ダウンリンク周波数帯域における、前記マクロセルから前記スモールセルへの前記端末装置のセル間ハンドオーバを含む、前記(3)又は(4)のいずれか1項に記載の通信制御装置。
(6)
前記ハンドオーバは、前記スモールセルにおける、前記マクロセルの前記ダウンリンク周波数帯域への前記端末装置の周波数間ハンドオーバを含む、前記(3)~(5)のいずれか1項に記載の通信制御装置。
(7)
前記ハンドオーバは、前記端末装置が前記マクロセルのアップリンク周波数帯域を用いて前記スモールセルで無線通信することを可能にするハンドオーバである、前記(1)に記載の通信制御装置。
(8)
前記制御部は、前記測定結果に基づいて、前記アップリンク周波数帯域における前記1つ以上の別の端末装置の送信電力を制御する、前記(7)に記載の通信制御装置。
(9)
前記ハンドオーバは、前記アップリンク周波数帯域における、前記マクロセルから前記スモールセルへの前記端末装置のセル間ハンドオーバを含む、前記(8)に記載の通信制御装置。
(10)
前記ハンドオーバは、前記スモールセルにおける、前記マクロセルの前記アップリンク周波数帯域への前記端末装置の周波数間ハンドオーバを含む、前記(8)又は(9)に記載の通信制御装置。
(11)
前記制御部は、前記測定結果に基づいて、前記ハンドオーバを実行するか否かを決定する、前記(1)に記載の通信制御装置。
(12)
前記ハンドオーバは、前記マクロセルから前記スモールセルへの前記端末装置のセル間ハンドオーバであり、
前記制御部は、前記測定結果に基づいて、前記マクロセルのダウンリンク周波数帯域における前記ハンドオーバを実行するか否かを決定し、又は前記マクロセルのアップリンク周波数帯域における前記ハンドオーバを実行するか否かを決定し、
前記マクロセルのダウンリンク周波数帯域における前記ハンドオーバ及び前記マクロセルのアップリンク周波数帯域における前記ハンドオーバのうちの少なくとも一方は、実行される、
前記(11)に記載の通信制御装置。
(13)
前記ハンドオーバは、前記スモールセルにおける前記端末装置の周波数間ハンドオーバである、前記(11)に記載の通信制御装置。
(14)
前記制御部は、前記マクロセルのダウンリンク周波数帯域への前記ハンドオーバ及び前記マクロセルのアップリンク周波数帯域への前記ハンドオーバのうちのいずれを実行するかを決定する、前記(13)に記載の通信制御装置。
(15)
前記マクロセル及び前記スモールセルでは、複数の周波数帯域が用いられ、
前記取得部は、前記ハンドオーバの際に、前記複数の周波数帯域における前記干渉の度合いの測定結果を取得し、
前記制御部は、前記測定結果に基づいて、前記複数の周波数帯域のうちの個々の周波数帯域について、前記ハンドオーバを実行するか否かを決定する、
前記(11)に記載の通信制御装置。
(16)
前記ハンドオーバは、前記マクロセルから前記スモールセルへの前記端末装置のセル間ハンドオーバであり、
前記制御部は、前記個々の周波数帯域における前記ハンドオーバを実行するか否かを決定する、
前記(15)に記載の通信制御装置。
(17)
前記ハンドオーバは、前記スモールセルにおける前記端末装置の周波数間ハンドオーバであり、
前記制御部は、前記複数の周波数帯域のうちのいずれの周波数帯域への前記ハンドオーバを実行するかを決定する、
前記(15)に記載の通信制御装置。
(18)
周波数帯域を用いてFDD方式での無線通信が行われるマクロセルであって、前記周波数帯域を用いてTDD方式での無線通信が行われるスモールセルの一部又は全体と重複する当該マクロセル内で、端末装置と無線通信することと、
端末装置が前記スモールセルで無線通信することを可能にする当該端末装置のハンドオーバの際に、前記マクロセル内で無線通信する1つ以上の別の端末装置と前記端末装置との間における干渉の度合いの測定結果を取得することと、
前記測定結果に基づいて、前記ハンドオーバを制御することと、
を含む通信制御方法。
(19)
周波数帯域を用いてFDD方式での無線通信が行われるマクロセルと一部又は全体で重複するスモールセルであって、前記周波数帯域を用いてTDD方式での無線通信が行われる前記スモールセルで、端末装置が無線通信することを可能にする、当該端末装置のハンドオーバの際に、前記マクロセル内で無線通信する1つ以上の別の端末装置と前記端末装置との間における干渉の度合いの測定結果を取得する取得部と、
前記測定結果に基づいて、前記ハンドオーバを制御する制御部と、
を備える通信制御装置。
(20)
周波数帯域を用いてFDD方式での無線通信が行われるマクロセルであって、前記周波数帯域を用いてTDD方式での無線通信が行われるスモールセルの一部又は全体と重複する当該マクロセル内で、当該マクロセルの基地局と無線通信し、前記スモールセル内で、当該スモールセルの基地局と無線通信する無線通信部と、
自装置が前記スモールセルで無線通信することを可能にする自装置のハンドオーバの際に、前記マクロセル内で無線通信する1つ以上の別の端末装置と自装置との間における干渉の度合いの測定のための制御を行う制御部と、
を備え、
前記ハンドオーバは、前記測定の結果に基づいて制御される、
端末装置。
10 マクロセル
30 スモールセル
100 eNodeB/eNB
110 無線通信部
120 ネットワーク通信部
130 記憶部
140 制御部
141 測定結果取得部
143 ハンドオーバ制御部/HO制御部
200 UE(User Equipment)
210 無線通信部
220 記憶部
230 制御部
300 Home eNodeB/HeNB
Claims (20)
- 周波数帯域を用いてFDD方式での無線通信が行われるマクロセルであって、前記周波数帯域を用いてTDD方式での無線通信が行われるスモールセルの一部又は全体と重複する当該マクロセル内で、端末装置と無線通信する無線通信部と、
端末装置が前記スモールセルで無線通信することを可能にする当該端末装置のハンドオーバの際に、前記マクロセル内で無線通信する1つ以上の別の端末装置と前記端末装置との間における干渉の度合いの測定結果を取得する取得部と、
前記測定結果に基づいて、前記ハンドオーバを制御する制御部と、
を備える通信制御装置。 - 前記ハンドオーバは、前記端末装置が前記マクロセルのダウンリンク周波数帯域を用いて前記スモールセルで無線通信することを可能にするハンドオーバである、請求項1に記載の通信制御装置。
- 前記制御部は、前記測定結果に基づいて、ランダムアクセスチャネルに関する前記端末装置のパラメータを制御する、請求項2に記載の通信制御装置。
- 前記パラメータは、前記ランダムアクセスチャネルにおける前記端末装置の送信電力である、請求項3に記載の通信制御装置。
- 前記ハンドオーバは、前記ダウンリンク周波数帯域における、前記マクロセルから前記スモールセルへの前記端末装置のセル間ハンドオーバを含む、請求項3に記載の通信制御装置。
- 前記ハンドオーバは、前記スモールセルにおける、前記マクロセルの前記ダウンリンク周波数帯域への前記端末装置の周波数間ハンドオーバを含む、請求項3に記載の通信制御装置。
- 前記ハンドオーバは、前記端末装置が前記マクロセルのアップリンク周波数帯域を用いて前記スモールセルで無線通信することを可能にするハンドオーバである、請求項1に記載の通信制御装置。
- 前記制御部は、前記測定結果に基づいて、前記アップリンク周波数帯域における前記1つ以上の別の端末装置の送信電力を制御する、請求項7に記載の通信制御装置。
- 前記ハンドオーバは、前記アップリンク周波数帯域における、前記マクロセルから前記スモールセルへの前記端末装置のセル間ハンドオーバを含む、請求項8に記載の通信制御装置。
- 前記ハンドオーバは、前記スモールセルにおける、前記マクロセルの前記アップリンク周波数帯域への前記端末装置の周波数間ハンドオーバを含む、請求項8に記載の通信制御装置。
- 前記制御部は、前記測定結果に基づいて、前記ハンドオーバを実行するか否かを決定する、請求項1に記載の通信制御装置。
- 前記ハンドオーバは、前記マクロセルから前記スモールセルへの前記端末装置のセル間ハンドオーバであり、
前記制御部は、前記測定結果に基づいて、前記マクロセルのダウンリンク周波数帯域における前記ハンドオーバを実行するか否かを決定し、又は前記マクロセルのアップリンク周波数帯域における前記ハンドオーバを実行するか否かを決定し、
前記マクロセルのダウンリンク周波数帯域における前記ハンドオーバ及び前記マクロセルのアップリンク周波数帯域における前記ハンドオーバのうちの少なくとも一方は、実行される、
請求項11に記載の通信制御装置。 - 前記ハンドオーバは、前記スモールセルにおける前記端末装置の周波数間ハンドオーバである、請求項11に記載の通信制御装置。
- 前記制御部は、前記マクロセルのダウンリンク周波数帯域への前記ハンドオーバ及び前記マクロセルのアップリンク周波数帯域への前記ハンドオーバのうちのいずれを実行するかを決定する、請求項13に記載の通信制御装置。
- 前記マクロセル及び前記スモールセルでは、複数の周波数帯域が用いられ、
前記取得部は、前記ハンドオーバの際に、前記複数の周波数帯域における前記干渉の度合いの測定結果を取得し、
前記制御部は、前記測定結果に基づいて、前記複数の周波数帯域のうちの個々の周波数帯域について、前記ハンドオーバを実行するか否かを決定する、
請求項11に記載の通信制御装置。 - 前記ハンドオーバは、前記マクロセルから前記スモールセルへの前記端末装置のセル間ハンドオーバであり、
前記制御部は、前記個々の周波数帯域における前記ハンドオーバを実行するか否かを決定する、
請求項15に記載の通信制御装置。 - 前記ハンドオーバは、前記スモールセルにおける前記端末装置の周波数間ハンドオーバであり、
前記制御部は、前記複数の周波数帯域のうちのいずれの周波数帯域への前記ハンドオーバを実行するかを決定する、
請求項15に記載の通信制御装置。 - 周波数帯域を用いてFDD方式での無線通信が行われるマクロセルであって、前記周波数帯域を用いてTDD方式での無線通信が行われるスモールセルの一部又は全体と重複する当該マクロセル内で、端末装置と無線通信することと、
端末装置が前記スモールセルで無線通信することを可能にする当該端末装置のハンドオーバの際に、前記マクロセル内で無線通信する1つ以上の別の端末装置と前記端末装置との間における干渉の度合いの測定結果を取得することと、
前記測定結果に基づいて、前記ハンドオーバを制御することと、
を含む通信制御方法。 - 周波数帯域を用いてFDD方式での無線通信が行われるマクロセルと一部又は全体で重複するスモールセルであって、前記周波数帯域を用いてTDD方式での無線通信が行われる前記スモールセルで、端末装置が無線通信することを可能にする、当該端末装置のハンドオーバの際に、前記マクロセル内で無線通信する1つ以上の別の端末装置と前記端末装置との間における干渉の度合いの測定結果を取得する取得部と、
前記測定結果に基づいて、前記ハンドオーバを制御する制御部と、
を備える通信制御装置。 - 周波数帯域を用いてFDD方式での無線通信が行われるマクロセルであって、前記周波数帯域を用いてTDD方式での無線通信が行われるスモールセルの一部又は全体と重複する当該マクロセル内で、当該マクロセルの基地局と無線通信し、前記スモールセル内で、当該スモールセルの基地局と無線通信する無線通信部と、
自装置が前記スモールセルで無線通信することを可能にする自装置のハンドオーバの際に、前記マクロセル内で無線通信する1つ以上の別の端末装置と自装置との間における干渉の度合いの測定のための制御を行う制御部と、
を備え、
前記ハンドオーバは、前記測定の結果に基づいて制御される、
端末装置。
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CN109219064B (zh) * | 2017-06-30 | 2021-11-23 | 中国移动通信集团浙江有限公司 | 一种tdd/fdd网络互操作处理方法及基站 |
Also Published As
Publication number | Publication date |
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US20150333852A1 (en) | 2015-11-19 |
EP2882228A4 (en) | 2016-03-09 |
JPWO2014010289A1 (ja) | 2016-06-20 |
EP2882228A1 (en) | 2015-06-10 |
CN104412651A (zh) | 2015-03-11 |
CN104412651B (zh) | 2018-12-18 |
JP6179514B2 (ja) | 2017-08-16 |
US9735901B2 (en) | 2017-08-15 |
EP2882228B1 (en) | 2020-02-19 |
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