JP2014146865A - Terminal device, base station device, communication system, measuring method and integrated circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide techniques related to a terminal device, base station device, communication system, measuring method and an integrated circuit that improve communication quality by efficiently performing the evaluation of cell measurement quality.SOLUTION: When a terminal device evaluates measurement event conditions to compare cell measurement quality, it changes the measurement event conditions on the basis of travel speed information estimated by the terminal device and a cell type, and reports the evaluation result of the changed measurement event conditions to a base station device.

Description

  Embodiments described herein relate generally to a terminal device, a base station device, a communication system, a measurement method, and an integrated circuit technology that improve communication quality by efficiently evaluating cell measurement quality.

  Evolved which realized high-speed communication by adopting OFDM (Orthogonal Frequency-Division Multiplexing) communication method and flexible scheduling of predetermined frequency and time unit called resource block in 3GPP (3rd Generation Partnership Project) which is a standardization project The standardization of Universal Terrestrial Radio Access (hereinafter referred to as EUTRA) was carried out.

  In 3GPP, Advanced EUTRA is discussed for realizing higher-speed data transmission and having upward compatibility with EUTRA. In EUTRA, a communication system is premised on a network in which base station apparatuses have substantially the same cell configuration (cell size). However, in Advanced EUTRA, base station apparatuses (cells) having different configurations are mixed in the same area. A communication system based on a network (a heterogeneous wireless network, a heterogeneous network) is being discussed. In a communication system based on a heterogeneous network, the mobility control function of a terminal device based on a conventional communication system may not operate correctly.

  For example, when a terminal device moves between cells by performing a handover between a cell having a large cell radius (for example, a macro cell) and a cell having a small cell radius (for example, a small cell (for example, a pico cell)) Non-Patent Document 1 shows that when a cell is changed), the failure probability of handover of a terminal device moving at high speed is higher than that of a terminal device moving at low speed or medium speed.

  In order to solve this problem, Non-Patent Document 2 focuses on the high probability of handover failure especially when a terminal device moves from a cell with a small cell radius to a cell with a large cell radius. It has been proposed to apply an event-specific offset value according to the cell type or to scale the handover evaluation time.

R2-1222804, Intel Corporation, Prague, Czech, May 21st-25th 2012. http: // www. 3 gpp. org / ftp / tsg_ran / WG2_RL2 / TSGR2_78 / Docs / R2-123343, CATT, CATR, Qingdao, P.R. R. China, August 13th-17th, 2012. http: // www. 3 gpp. org / ftp / tsg_ran / WG2_RL2 / TSGR2_79 / Docs /

  When the terminal apparatus performs handover from the serving cell to another neighboring cell, an offset value can be added to the actual measurement quality in order to promote or suppress the handover trigger. That is, as in Non-Patent Document 2, a method of uniformly applying an event-specific offset value according to the type (type) of a handover target cell is effective in a network composed of cells of the same type. On the other hand, in a network composed of heterogeneous cells such as a heterogeneous network, the offset value is expected to be different for each cell even for the same cell type.

  That is, in the method of uniformly applying an event-specific offset value according to the type (type) of the handover target cell, a large offset value exceeding, for example, 6 dB (decibel) is set for the constituent cells. In such a case, there is a problem that the effect becomes low.

  In view of the above problems, an object of an embodiment of the present invention is to provide a terminal device, a base station device, a communication system, a measurement method, and an integrated circuit that improve communication quality by efficiently evaluating cell measurement quality. It aims at providing the technology about.

  (1) In order to achieve the above object, the following measures were taken. That is, the terminal apparatus in the embodiment of the present invention is a terminal apparatus that communicates with the base station apparatus, and the moving speed information estimated by the terminal apparatus when evaluating measurement event conditions for comparing measurement quality of cells. A base station device and a terminal device communicate with each other, and means for changing the measurement event condition based on the cell type and means for reporting the evaluation result of the changed measurement event condition to the base station device. A terminal device in a communication system.

  (2) In addition, the terminal device in the embodiment of the present invention is a terminal device that communicates with the base station device, a unit that receives information indicating whether or not to apply an additional measurement event condition, and cell measurement A base station apparatus and a terminal comprising means for evaluating the additional measurement event condition based on the moving speed information estimated by the terminal apparatus and the cell type when evaluating the measurement event condition for comparing quality A terminal device in a communication system in which the device communicates.

  Thereby, since a terminal device measures a cell using the changed measurement event condition, it can evaluate measurement quality efficiently and can improve communication quality.

  (3) Moreover, the base station apparatus in the embodiment of the present invention is a base station apparatus that communicates with a terminal apparatus, and when starting evaluation of measurement event conditions for comparing measurement quality of cells by the terminal apparatus, A base station apparatus and a terminal apparatus communicate with each other, comprising means for setting and notifying information indicating whether or not to change the measurement event condition based on movement speed information estimated by the terminal apparatus and the type of the cell 1 is a base station apparatus in a communication system.

  (4) Moreover, the base station apparatus in the embodiment of the present invention is a base station apparatus that communicates with a terminal apparatus, and when starting evaluation of measurement event conditions for comparing measurement quality of cells by the terminal apparatus, A base station device and a terminal device comprising means for setting and notifying information indicating whether or not to apply an additional measurement event condition based on the moving speed information estimated by the terminal device and the type of the cell. It is the base station apparatus in the communication system which communicates.

  Thereby, the base station apparatus causes the terminal apparatus to measure the cell using the changed measurement event condition, so that the measurement quality can be evaluated efficiently and the communication quality can be improved.

  (5) A communication system according to an embodiment of the present invention is a communication system in which a base station apparatus and a terminal apparatus communicate with each other, and the base station apparatus measures a measurement event for comparing measurement quality of cells by the terminal apparatus. Means for setting and notifying information indicating whether or not to change the measurement event condition based on the moving speed information estimated by the terminal device and the cell type when starting the evaluation of the condition; The terminal device includes means for receiving information indicating whether or not to change the measurement event condition, information indicating whether or not to change the measurement event condition, and movement speed information estimated by the terminal device; A communication system comprising: means for changing the measurement event condition based on the cell type; and means for reporting the evaluation result of the changed measurement event condition to the base station apparatus A.

  (6) Moreover, the communication system in embodiment of this invention is a communication system with which a base station apparatus and a terminal device communicate, Comprising: The said base station apparatus is a measurement event which compares the measurement quality of the cell by the said terminal device. A unit for setting and notifying information indicating whether or not to apply the additional measurement event condition based on the moving speed information estimated by the terminal device and the cell type when starting the evaluation of the condition; The terminal device receives means indicating whether to apply the additional measurement event condition, information indicating whether the measurement event condition is applied, and movement estimated by the terminal device A communication system comprising means for evaluating the additional measurement event condition based on speed information and a type of the cell.

  As a result, the base station device causes the terminal device to measure the cell using the changed measurement event condition, and the terminal device measures the cell using the changed measurement event condition. Communication quality can be improved.

  (7) Moreover, the measurement method in the embodiment of the present invention is a measurement method of a terminal device that communicates with a base station device, and in the evaluation of measurement event conditions for comparing measurement quality of cells, A base station device comprising: changing the measurement event condition based on estimated moving speed information and a type of the cell; and reporting an evaluation result of the changed measurement event condition to the base station device; It is the measuring method of the terminal device in the communication system with which a terminal device communicates.

  (8) Moreover, the measurement method in the embodiment of the present invention is a measurement method of a terminal device that communicates with a base station device, and receives information indicating whether or not to apply an additional measurement event condition; A base station comprising a step of evaluating the additional measurement event condition based on the moving speed information estimated by the terminal device and the cell type when evaluating the measurement event condition for comparing the measurement quality of the cell. A terminal device measurement method in a communication system in which a station device and a terminal device communicate with each other.

  Thereby, since the measuring method of a terminal device turns into a measuring method which measures a cell using the changed measurement event conditions, evaluation of measurement quality can be performed efficiently and communication quality can be improved.

  (9) Moreover, the integrated circuit in the embodiment of the present invention is an integrated circuit mounted on a terminal device that communicates with a base station device, and in the evaluation of the measurement event condition for comparing the measurement quality of the cells, A function of changing the measurement event condition based on movement speed information estimated by the terminal device and a type of the cell; and a function of reporting an evaluation result of the changed measurement event condition to the base station device. The integrated circuit of the terminal device in the communication system in which the base station device and the terminal device communicate with each other.

  (10) An integrated circuit according to an embodiment of the present invention is an integrated circuit mounted on a terminal device that communicates with a base station device, and receives information indicating whether or not to apply an additional measurement event condition. And a function for evaluating the additional measurement event condition based on the moving speed information estimated by the terminal device and the type of the cell when evaluating the measurement event condition for comparing the measurement quality of the cell. It is an integrated circuit of a terminal device in a communication system having a function to be exhibited by the terminal device, in which a base station device and the terminal device communicate.

  As a result, the integrated circuit of the terminal device allows the terminal device to perform the function of measuring cells using the changed measurement event condition, so that the measurement quality can be evaluated efficiently and the communication quality can be improved. Can do.

  In the present specification, each embodiment is disclosed in terms of technologies related to a terminal device, a base station device, a communication system, a measurement method, and an integrated circuit that realize efficient evaluation of measurement quality of a cell. The applicable communication method is not limited to a communication method that is upward compatible with EUTRA, such as EUTRA or Advanced EUTRA.

  For example, the techniques described herein include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal FDMA (OFDMA) systems, single carrier FDMA (SC -It can be used in various communication systems, such as FDMA) systems, and other systems. Further, in this specification, a system and a network can be used synonymously.

  Also, the terminal device and the base station device aggregate (aggregate) frequencies (component carriers or frequency bands) of a plurality of different frequency bands (frequency bands) by carrier aggregation into one frequency (frequency band). You may apply the technique handled like. Component carriers include uplink component carriers corresponding to the uplink and downlink component carriers corresponding to the downlink.

  For example, when five component carriers having a frequency bandwidth of 20 MHz are aggregated by carrier aggregation, a terminal device capable of carrier aggregation regards these as a frequency bandwidth of 100 MHz and performs transmission / reception. The component carriers to be aggregated may be continuous frequencies, or may be frequencies at which all or part of them are discontinuous. For example, when the usable frequency band is 800 MHz band, 2 GHz band, and 3.5 GHz band, one component carrier is transmitted in the 800 MHz band, another component carrier is transmitted in the 2 GHz band, and another component carrier is transmitted in the 3.5 GHz band. It may be.

  It is also possible to aggregate a plurality of continuous or discontinuous component carriers in the same frequency band. The frequency bandwidth of each component carrier may be a frequency bandwidth (for example, 5 MHz or 10 MHz) narrower than the receivable frequency bandwidth (for example, 20 MHz) of the terminal device, and the aggregated frequency bandwidth may be different from each other. . The frequency bandwidth is preferably equal to one of the frequency bandwidths of the conventional cell in consideration of backward compatibility, but may be a different frequency bandwidth. Moreover, the component carrier (carrier type) which is not backward compatible may be sufficient. Note that the number of uplink component carriers assigned (set or added) to the terminal device by the base station device is preferably equal to or less than the number of downlink component carriers.

  A cell composed of an uplink component carrier in which an uplink control channel is set for a radio resource request and a downlink component carrier that is cell-specifically connected to the uplink component carrier is a primary cell (PCell). It is called. Moreover, the cell comprised from component carriers other than a primary cell is called a secondary cell (SCell: Secondary cell). The terminal apparatus performs paging message reception, broadcast information update detection, initial access procedure, and the like in the primary cell, but does not perform these in the secondary cell.

  The primary cell is not subject to activation and deactivation control (that is, it is always considered to be activated), but the secondary cell is in a state of activation and deactivation. These state changes are explicitly specified from the base station apparatus, and the state is changed based on a timer set in the terminal apparatus for each component carrier. The primary cell and the secondary cell are collectively referred to as a serving cell.

  According to an embodiment of the present invention, it is possible to provide a technology related to a terminal device, a base station device, a communication system, a measurement method, and an integrated circuit that improve communication quality by efficiently evaluating cell measurement quality. I can do it.

It is a block diagram which shows an example of schematic structure of the terminal device which concerns on embodiment of this invention. It is a block diagram which shows an example of schematic structure of the base station apparatus which concerns on embodiment of this invention. It is a block diagram which shows an example of schematic structure of the measurement process part of the terminal device which concerns on embodiment of this invention. It is a figure for demonstrating the adjustment method of the parameter regarding the measurement event condition of the terminal device which concerns on the 1st Embodiment of this invention.

  A technique related to each embodiment of the present invention will be briefly described below.

[Physical channel / Physical signal]
The main physical channels and physical signals used in EUTRA and Advanced EUTRA will be described. A channel means a medium used for signal transmission, and a physical channel means a physical medium used for signal transmission. In the present invention, a physical channel can be used synonymously with a signal. The physical channel may be added in the future in EUTRA and Advanced EUTRA, or the structure and format of the physical channel may be changed or added. It does not affect.

  In EUTRA and Advanced EUTRA, scheduling of physical channels / physical signals is managed using radio frames. One radio frame is 10 ms, and one radio frame is composed of 10 subframes. Further, one subframe is composed of two slots (that is, one subframe is 1 ms, and one slot is 0.5 ms). Also, resource blocks are used as a minimum scheduling unit in which physical channels are allocated. A resource block is defined by a constant frequency region composed of a set of a plurality of subcarriers (for example, 12 subcarriers) and a region composed of a constant transmission time interval (1 slot) on the frequency axis.

  Synchronization signals (Synchronization Signals) are composed of three types of primary synchronization signals and secondary synchronization signals composed of 31 types of codes arranged alternately in the frequency domain. Depending on the combination, 504 cell identifiers (Physical Cell Identity (PCI)) for identifying the base station apparatus and frame timing for radio synchronization are shown. The terminal device specifies the physical cell ID of the synchronization signal received by the cell search.

  A physical broadcast information channel (PBCH; Physical Broadcast Channel) is transmitted for the purpose of notifying (setting) control parameters (broadcast information (system information): System information) that are commonly used by terminal devices in a cell. Broadcast information that is not notified on the physical broadcast information channel is transmitted as a layer 3 message (system information) on the physical downlink shared channel after the radio resource is notified on the physical downlink control channel.

  As broadcast information, a cell global identifier (CGI) indicating a cell-specific identifier, a tracking area identifier (TAI) for managing a standby area by paging, random access setting information (such as a transmission timing timer), Common radio resource setting information and the like are notified.

  The downlink reference signal is classified into a plurality of types according to its use. For example, cell-specific reference signals (RS) are pilot signals transmitted at a predetermined power for each cell, and are downlink reference signals that are periodically repeated in the frequency domain and the time domain based on a predetermined rule. It is. The terminal device measures the reception quality for each cell by receiving the cell-specific RS. The terminal apparatus also uses the downlink cell-specific RS as a reference signal for demodulating the physical downlink control channel or the physical downlink shared channel transmitted simultaneously with the cell-specific RS. As a sequence used for the cell-specific RS, a sequence that can be identified for each cell is used.

  The downlink reference signal is also used for estimation of downlink propagation path fluctuations. A downlink reference signal used for estimation of propagation path fluctuation is referred to as a channel state information reference signal (CSI-RS). Also, the downlink reference signal set individually for each terminal device is referred to as UE-specific reference signals (URS) or Dedicated RS (DRS), and demodulates the physical downlink control channel or the physical downlink shared channel. Referenced for the channel compensation process.

  A physical downlink control channel (PDCCH) is transmitted from the head of each subframe using several OFDM symbols (for example, 1 to 4 OFDM symbols), and is based on scheduling of the base station apparatus to the terminal apparatus. It is used for the purpose of instructing radio resource allocation information and an adjustment amount for increase / decrease in transmission power.

  Before transmitting / receiving layer 3 messages (paging, handover command, etc.) that are downlink data and downlink control data, the terminal apparatus monitors (monitors) the physical downlink control channel addressed to itself and By receiving the physical downlink control channel, it is necessary to acquire radio resource allocation information called an uplink grant during transmission and a downlink grant (downlink assignment) during reception from the physical downlink control channel. Note that the physical downlink control channel may be configured to be transmitted in the area of the resource block that is allocated individually (dedicated) from the base station apparatus to the terminal apparatus, in addition to the above-described ODFM symbol. Is possible.

  The physical uplink control channel (PUCCH) is a reception confirmation response (ACK / NACK; Acknowledgement / Negative Acknowledgment) or downlink propagation path (channel state) information transmitted on the physical downlink shared channel. (CSI; Channel State Information), used for making a scheduling request (SR) that is an uplink radio resource allocation request (radio resource request).

  CSI includes CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), PTI (Precoding Type Indicator), and RI (Rank Indicator). Each indicator may be expressed as “Indication”, but its use and meaning are the same.

  The Physical Downlink Shared Channel (PDSCH) is used to notify the terminal apparatus as broadcast data (system information) not notified by the paging or physical broadcast information channel as a layer 3 message in addition to the downlink data. Is done. The radio resource allocation information of the physical downlink shared channel is indicated by the physical downlink control channel. The physical downlink shared channel is transmitted after being arranged in an OFDM symbol other than the OFDM symbol through which the physical downlink control channel is transmitted. That is, the physical downlink shared channel and the physical downlink control channel are time division multiplexed within one subframe.

  A physical uplink shared channel (PUSCH) mainly transmits uplink data and uplink control data, and can also include control data such as downlink reception quality and ACK / NACK. In addition to uplink data, it is also used to notify the base station apparatus of uplink control information as a layer 3 message. Similarly to the downlink, the radio resource allocation information of the physical uplink shared channel is indicated by the physical downlink control channel.

  The uplink reference signal (uplink reference signal; uplink pilot signal, also referred to as uplink pilot channel) is transmitted from the base station apparatus to the physical uplink control channel PUCCH and / or the physical uplink shared channel PUSCH. A demodulation reference signal (DMRS) used for demodulation and a sounding reference signal (SRS) used mainly by the base station apparatus to estimate an uplink channel state are included. It is. The sounding reference signal includes a periodic sounding reference signal (Periodic SRS) and an aperiodic sounding reference signal (Aperiodic SRS).

  A physical random access channel (PRACH) is a channel used for reporting (setting) a preamble sequence and has a guard time. The preamble sequence is configured so as to express 6-bit information by preparing 64 types of sequences. The physical random access channel is used as an access means for the terminal device to the base station device. The terminal apparatus also transmits a radio resource request when the physical uplink control channel is not set, and transmission timing adjustment information (timing advance (TA)) necessary for matching the uplink transmission timing to the reception timing window of the base station apparatus. Is called a physical random access channel.

  Specifically, the terminal device transmits a preamble sequence using the radio resource of the physical random access channel set by the base station device. The terminal device that has received the transmission timing adjustment information sets a transmission timing timer (TA timer) that measures the effective time of the transmission timing adjustment information that is commonly set by the broadcast information (or set individually by the layer 3 message). The uplink state is managed as a transmission timing adjustment state during the valid time (during timing) of the transmission timing timer, and as a transmission timing non-adjustment state (transmission timing unadjusted state) outside the valid period (during stop).

  The layer 3 message is a control-plane message exchanged between the terminal apparatus and the base station apparatus in the RRC (Radio Resource Control) layer, and can be used synonymously with RRC signaling or RRC message. Since other physical channels are not related to each embodiment of the present invention, detailed description thereof is omitted.

[Wireless network]
The communicable range (communication area) of each frequency controlled by the base station apparatus is regarded as a cell. At this time, the communication area covered by the base station apparatus may have a different width and a different shape for each frequency. Moreover, the area to cover may differ for every frequency. A wireless network in which cells having different types of base station apparatuses and different cell radii are mixed at the same frequency to form one communication system is referred to as a heterogeneous network. The base station apparatus may manage a plurality of cells.

  The terminal device operates by regarding the inside of the cell as a communication area. The size of the communication area is determined by the size of the transmission power of the base station device. When a terminal device moves from one cell to another cell, it moves to another appropriate cell by a cell reselection procedure during non-wireless connection (during non-communication) and by a handover procedure during wireless connection (during communication). To do. An appropriate cell is a cell that is generally determined that access by a terminal device is not prohibited based on information specified by a base station device, and the downlink reception quality satisfies a predetermined condition. Indicates the cell to be used.

  Note that carrier aggregation is communication using a plurality of cells having different frequencies using a plurality of component carriers (frequency bands), and is also referred to as cell aggregation. The terminal device may be wirelessly connected to the base station device via a relay station device (or repeater) for each frequency. That is, the base station apparatus of each embodiment of the present invention can be replaced with a relay station apparatus.

  A base station apparatus defined by 3GPP is referred to as a Node B (NodeB), and a base station apparatus in EUTRA and Advanced EUTRA is referred to as an eNodeB (eNodeB). Note that a terminal device in EUTRA and Advanced EUTRA defined by 3GPP is referred to as a UE (User Equipment). The base station apparatus manages a cell, which is an area in which the terminal apparatus can communicate with the base station apparatus, for each frequency. A cell is also referred to as a macro cell, a femto cell, a pico cell, or a nano cell depending on the size of an area that can communicate with a terminal device. A cell having a small area with respect to a macro cell is also referred to as a small cell. In addition, when the terminal device can communicate with a certain base station device, the cell used for communication with the terminal device among the cells of the base station device is a serving cell, and other cells Is referred to as a neighbor cell.

[Measurement Event Evaluation Procedure]
The measurement event evaluation procedure is performed based on measurement event information set in a measurement configuration set for the terminal device when the terminal device is connected to a certain cell.

  More specifically, the terminal device compares the reception quality (measurement quality) of one connected cell with the reception quality (measurement quality) of another cell (neighboring cell) or a threshold value. When the reception quality of one cell in a certain area satisfies the condition (measurement event condition) set as measurement event information, the content of the measurement event that satisfies the condition and, if necessary, the condition of the measurement event are satisfied Report the cell to the base station apparatus. On the other hand, the terminal device stops reporting the measurement event to the base station device when the reported (established) measurement event does not satisfy the condition.

  The terminal device evaluates the conditions of a plurality of measurement events at the same time. The conditions for satisfying the measurement event are, for example, (1) the reception quality of one serving cell exceeds the set threshold value, and (2) the reception quality of one serving cell falls below the set threshold value. (3) The reception quality of the neighboring cell exceeds the reception quality of one serving cell, (4) The reception quality of the neighboring cell exceeds the set threshold value, (5) One certain serving area This is an evaluation criterion for indicating that the reception quality of the cell is below the set threshold value and that the reception quality of the neighboring cells is above the set threshold value. Moreover, you may be comprised so that measurement events other than this may be evaluated.

  As a condition for satisfying the measurement event, a continuous time in which (1) to (5) are satisfied may be added as an additional condition. The continuous time is set in the terminal device by the base station device. The continuous time (measurement event evaluation time) until the trigger of the measurement event is also referred to as a time-to-trigger (TTT).

  An example in which the measurement event evaluation time is applied will be described. For example, in the case of the measurement event (1) described above, the terminal device does not determine that the measurement event is satisfied at a timing when the reception quality of a certain serving cell exceeds the set threshold. Instead, the terminal device starts measuring the measurement event evaluation time based on the timing when the reception quality of a certain serving cell exceeds the set threshold value, and the reception quality of the serving cell is determined by the measurement event evaluation time. If the threshold value is continuously exceeded for the time indicated by, it is determined that the measurement event is satisfied. When the measurement event evaluation time is set, the terminal device similarly performs evaluation in consideration of the measurement event evaluation time also in other measurement events.

  The measurement event evaluation time may be scaled (scaling, enlarged or reduced) based on moving speed information indicating an estimated speed (Mobility state estimation (MSE), also referred to as mobility state estimation) of the terminal device. The terminal device estimates the moving speed level (low speed, medium speed, high speed) depending on how many times the cell is changed by handover per time specified by the base station apparatus, and manages it as moving speed information. Good. The scaled ratio may be different depending on the estimated moving speed information. For example, when the cell is changed N1 times during a certain time T1, the terminal apparatus estimates that the moving speed of the terminal apparatus is high. Further, when the cell is changed N2 times or more and less than N1 times during a certain time T1, the terminal apparatus estimates the moving speed of the terminal apparatus as a medium speed, and if it is less than N2 times, the terminal apparatus estimates a low speed. Further, if the cell is not changed more than M times during the separately designated time T2, the terminal apparatus resets the current speed and estimates that the speed is low.

  Further, when the terminal device is set by the base station device, the frequency-specific offset value (Ofp) of the serving cell and the serving cell specific to the reception quality (Mp) of a certain serving cell. An offset value (Ocp) may be added, and for the reception quality (Mn) of other cells (neighboring cells), the frequency cell-specific offset value (Ofn) and the neighboring cell-specific offset value (Ocn) May be added.

  Further, when the terminal device is set by the base station device, the terminal device may further add an offset value (Off) unique to the measurement event to the reception quality of a certain serving cell. That is, three offset values of Ofp, Ocp, and Off can be applied to the reception quality (Mp) of a certain serving cell. Similarly, two offset values of Ofn and Okn can be applied to the reception quality (Mn) of the neighboring cell.

  The terminal device may add hysteresis to the target event. Hysteresis is a suppression value that is applied for the purpose of preventing the measurement event condition from being met or not being met.

  However, when comparing cells having the same frequency, that is, in the case of intra-frequency measurements, the terminal device does not need to apply frequency-specific offset values (Ofp, Ofn). In other words, the terminal device applies frequency-specific offset values (Ofp, Ofn) in the case of inter-frequency measurements.

  The measurement setting is setting information regarding a plurality of measurements used for setting measurement event information in the terminal device. Measurement settings consist of measurement identifier information (Measurement ID), measurement target identifier information (Measurement objects ID), measurement target information (Measurement objects), reporting configuration identifier information (Reporting configuration ID), and reporting configuration information (Reporting configuration). The The measurement target identifier information is an index for designating and identifying the measurement target information. The report setting identifier information is an index for designating and identifying the report setting information.

  The measurement identifier information is used for associating the measurement target information with the report setting information. Specifically, the measurement identifier information is used as an identifier for link setting between the measurement target identifier information and the report setting identifier information. The measurement target information is used to designate a frequency to be measured by the terminal device. The report setting information is used to notify the setting of measurement event information (measurement event condition, measurement event evaluation time, speed related information, hysteresis, each offset value, etc.) related to the measurement event performed by the terminal device.

  In consideration of the above matters, appropriate embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the description of the embodiment of the present invention, when it is determined that a specific description of known functions and configurations related to the embodiment of the present invention obscures the gist of the embodiment of the present invention. Detailed description thereof will be omitted.

<First Embodiment>
A first embodiment of the present invention will be described below. The present embodiment relates to a measurement method for changing and applying evaluation of measurement events set in a terminal device.

  FIG. 1 is a block diagram showing an example of a terminal device 1 according to the first embodiment of the present invention. The terminal apparatus 1 includes a reception unit 101, a demodulation unit 102, a decoding unit 103, a measurement processing unit 104, a control unit 105, an uplink buffer control unit 106, an encoding unit 107, a modulation unit 108, a transmission unit 109, and uplink radio resources. The request control unit 110, the random access control unit 111, and the upper layer 112 are configured. The upper layer 112 is a block that realizes a specific function of an RRC (Radio Resource Control) layer that performs radio resource control. The uplink buffer control unit 106, the uplink radio resource request control unit 110, and the random access control unit 111 are blocks that realize specific functions of a MAC (Medium Access Control) layer that manages the data link layer.

  Note that the terminal device 1 includes a reception system block (receiving unit 101, demodulating unit 102, decoding unit 103) and a plurality of receiving systems in order to support simultaneous reception of a plurality of frequencies (frequency bands, frequency bandwidths) by carrier aggregation. In order to support simultaneous transmission of the same frequency (frequency band, frequency bandwidth), a plurality of transmission system blocks (encoding unit 107, modulation unit 108, transmission unit 109) may be provided.

  Regarding reception, terminal device control information is input from the upper layer 112 to the control unit 105. The terminal device control information is information necessary for wireless communication control of the terminal device 1 configured by the reception control information and the transmission control information. The wireless connection resource setting and the cell-specific notification individually transmitted from the base station device 2 It is set by information or system parameters, and the upper layer 112 inputs to the control unit 105 as necessary. The control unit 105 appropriately inputs reception control information that is control information related to reception to the reception unit 101, the demodulation unit 102, and the decoding unit 103.

  The reception control information includes information such as DRX control information, reception timing for each channel, multiplexing method, and radio resource arrangement information in addition to reception frequency band information. Further, the control unit 105 inputs measurement setting information necessary for control related to cell measurement to the measurement processing unit 104. The measurement setting information is information including measurement event information for determining a measurement event as to whether or not the measurement results of the serving cell and the peripheral cell measured by the terminal device 1 satisfy a designated measurement event. Moreover, the measurement setting information is information including neighboring cell information for determining whether or not the measurement result of the neighboring cell measured by the terminal device 1 satisfies the selection criteria regarding cell selection.

  The reception signal is received by the reception unit 101. The receiving unit 101 receives a signal in the frequency band specified by the reception control information. The received signal is input to the demodulation unit 102. Demodulation section 102 demodulates the received signal, inputs the signal to decoding section 103 to correctly decode downlink data and downlink control data, and inputs each decoded data to upper layer 112. Each data is also input to the measurement processing unit 104.

  Further, the measurement processing unit 104 measures the reception quality (SIR, SINR, RSRP, RSRQ, RSSI, path loss, etc.) of the downlink reference signal of the detected neighboring cell (component carrier), and generates a necessary measurement result. RSRP (Reference Signal Received Power) is a value (dBm) indicating the received power of the downlink reference signal in the measurement bandwidth, and RSRQ (Reference Signal Received Quality) is the quality of the downlink reference signal in the measurement bandwidth. This is a value (dB) indicated, and is calculated by the ratio of the total received power (RSSI (Received Signal Strength Indicator)) of the downlink reference signal in the measurement bandwidth and RSRP.

  The measurement processing unit 104 uses the measurement result as cell quality information for determining success or failure of the measurement event based on the set measurement event information. Further, the measurement processing unit 104 uses the measurement result as quality information for selection criteria for cell selection or cell reselection based on the set neighboring cell information. In addition, the signal used for the measurement is not limited to the downlink reference signal, and another signal may be measured as long as it is a signal used for measuring cell quality such as CSI-RS.

  As shown in FIG. 3, the measurement processing unit 104 includes neighboring cell information including information on the cell in the serving area and the cell detected by the cell search (physical cell ID, cell reception quality, cell type (described later)). The stored neighboring cell information management unit 301, the measurement parameter management unit 302 that stores the measurement event information input from the upper layer 112 and each measurement parameter information of the cell, the neighboring cell information management unit 301, and the measurement parameter management unit 302 And at least a measurement event evaluation unit 303 that evaluates a measurement event set based on the information.

  The measurement event evaluation unit 303 determines (determines) whether or not the measurement event condition set by the terminal device 1 from the base station device 2 is satisfied based on each input information. In other words, the terminal device 1 determines whether or not the measurement event condition is satisfied (Entering condition, subscription condition determination). Then, the measurement event evaluation unit 303 includes the information on the cell in which the measurement event condition is satisfied (satisfied) in the measurement event result information that is a part of the measurement result information, and inputs the information to the upper layer 112.

  In addition, the measurement event evaluation unit 303 determines (determines) whether the measurement event condition once satisfied is not satisfied. In other words, the terminal device 1 determines whether or not the measurement event condition once satisfied (Leaving condition, leaving condition determination). Then, the measurement event evaluation unit 303 includes the information on the cell in which the measurement event condition is not satisfied in the measurement event result information that is a part of the measurement result information, and inputs the information to the upper layer 112.

  Also, regarding transmission, terminal apparatus control information that is a control parameter for controlling each block is input from the upper layer 112 to the control unit 105, and transmission control information that is control information regarding transmission is transmitted to the uplink buffer control unit 106, The data is appropriately input to the encoding unit 107, the modulation unit 108, and the transmission unit 109. The transmission control information includes information such as DTX control information, coding information, modulation information, transmission frequency band information, transmission timing for each channel, multiplexing method, and radio resource allocation information as uplink scheduling information of the transmission signal. ing.

  Random access setting information is input from the upper layer 112 to the random access control unit 111. The random access setting information includes preamble information, radio resource information for transmission of a physical random access channel (power adjustment parameter, maximum preamble retransmission count, etc.), and the like. Further, the upper layer 112 manages transmission timing adjustment information and a transmission timing timer used for uplink transmission timing adjustment, and states of uplink transmission timing (transmission timing adjustment) for each cell (or for each cell group and each TA group). Status or transmission timing non-adjusted state). The transmission timing adjustment information and the transmission timing timer are included in the transmission control information.

  When it is necessary to manage a plurality of uplink transmission timing states, the upper layer 112 manages transmission timing adjustment information corresponding to the uplink transmission timing of each of the plurality of cells (or cell groups and TA groups). To do.

  The generated transmission data (uplink data and uplink control data) is input from the upper layer 112 to the uplink buffer control unit 106 at an arbitrary timing. At this time, the uplink buffer control unit 106 calculates the amount of input transmission data (uplink buffer amount). Resource request setting information is set in the uplink radio resource request control unit 110 by the higher layer 112. The resource request setting information includes at least transmission counter setting information and radio resource request prohibition timer information. Further, when the transmission data is input to the uplink buffer control unit 106, the uplink buffer control unit 106 notifies the uplink radio resource request control unit 110 of the generation of the transmission data, thereby transmitting to the uplink buffer. Signals that data exists.

  The uplink radio resource request control unit 110 determines whether radio resources necessary for transmitting the input transmission data are allocated. The uplink radio resource request control unit 110 generates one of a physical uplink shared channel PUSCH, a radio resource request using a physical uplink control channel (SR-PUCCH), or a physical random access channel based on radio resource allocation. Select and request control processing for transmitting the selected channel to the encoding unit 107 and / or the random access control unit 111.

  That is, when radio resources have already been allocated and transmission data can be transmitted using the physical uplink shared channel PUSCH, the encoding unit 107 allocates radio resources that have been allocated in accordance with an instruction from the uplink radio resource request control unit 110. The transmission data corresponding to is acquired from the uplink buffer control unit 106, encoded, and output to the modulation unit 108. Alternatively, when radio resources are not allocated and when a radio resource request (SR-PUCCH) using a physical uplink control channel is possible, the encoding unit 107 performs SR- in accordance with an instruction from the uplink radio resource request control unit 110. Control data necessary for transmission of PUCCH is encoded and output to modulation section 108.

  Alternatively, when the radio resource is not allocated and the radio resource request (SR-PUCCH) by the physical uplink control channel is impossible, the encoding unit 107 performs the random access procedure for the random access control unit 111. Instruct to start. At this time, the encoding unit 107 generates a preamble sequence transmitted through the physical random access channel based on the random access data information input from the random access control unit 111. The encoding unit 107 appropriately encodes each data according to the transmission control information and outputs the data to the modulation unit 108.

  Modulation section 108 appropriately performs modulation processing based on the channel structure for transmitting the output from coding section 107. The transmission unit 109 maps the output of the modulation unit 108 to the frequency domain, converts the frequency domain signal into a time domain signal, and performs power amplification on a carrier wave of a predetermined frequency. The transmission unit 109 also adjusts the uplink transmission timing according to the transmission timing adjustment information for each cell (also for each cell group and each TA group) input from the higher layer 112. The physical uplink shared channel in which the uplink control data is arranged can include, for example, a layer 3 message (radio resource control message; RRC message) in addition to the user data.

  In FIG. 1, other constituent elements of the terminal device 1 are omitted, but it is obvious that a plurality of blocks having other functions necessary to operate as the terminal device 1 are included as constituent elements.

  FIG. 2 is a block diagram showing an example of the base station apparatus 2 according to the first embodiment of the present invention. The base station apparatus includes a reception unit 201, a demodulation unit 202, a decoding unit 203, a control unit 204, a coding unit 205, a modulation unit 206, a transmission unit 207, an upper layer 208, and a network signal transmission / reception unit 209. Note that the base station apparatus 2 includes a reception system block (reception unit 201, demodulation unit 202, decoding unit 203) and a transmission system block (encoding unit) in order to support a plurality of frequencies (frequency bands and frequency bandwidths). 205, a modulation unit 206, and a transmission unit 207) may be provided.

  Upper layer 208 inputs downlink data and downlink control data to encoding section 205. The encoding unit 205 encodes the input data and inputs it to the modulation unit 206. Modulation section 206 modulates the encoded signal. The signal output from the modulation unit 206 is input to the transmission unit 207. Transmitter 207 maps the input signal to the frequency domain, then converts the frequency domain signal to a time domain signal, transmits the amplified signal on a carrier having a predetermined frequency, and transmits the signal. The physical downlink shared channel in which downlink control data is arranged typically constitutes a layer 3 message (RRC message).

  The receiving unit 201 converts a signal received from the terminal device 1 into a baseband digital signal. When a plurality of cells having different transmission timings are set for the terminal device 1, the receiving unit 201 receives signals at different timings for each cell (also for each cell group and each TA group). The digital signal converted by the reception unit 201 is input to the demodulation unit 202 and demodulated. The signal demodulated by the demodulation unit 202 is then input to the decoding unit 203 and decoded, and the correctly decoded uplink control data and uplink data are output to the upper layer 208.

  Base station apparatus control information necessary for control of each block is information necessary for radio communication control of the base station apparatus 2 configured by reception control information and transmission control information, and a higher-level network apparatus (MME or gateway apparatus). , OAM) and system parameters, and the upper layer 208 inputs to the control unit 204 as necessary.

  The control unit 204 transmits base station apparatus control information related to transmission to each block of the encoding unit 205, modulation unit 206, and transmission unit 207 as transmission control information, and base station apparatus control information related to reception to the reception control information. Are appropriately input to each block of the receiving unit 201, the demodulating unit 202, and the decoding unit 203. The RRC of the base station device 2 exists as part of the upper layer 208.

  On the other hand, the network signal transmission / reception unit 209 transmits (transfers) or receives a control message or user data between the base station apparatuses 2 or between the upper network apparatus and the base station apparatus 2. In FIG. 2, the other constituent elements of the base station apparatus 2 are omitted, but it is obvious that the constituent elements include a plurality of blocks having other functions necessary to operate as the base station apparatus 2.

  A measurement event processing method according to the first embodiment of the present invention will be described. The terminal device 1 is configured to perform the following measurement event processing when evaluating a measurement event for a neighboring cell during communication with a certain base station device 2.

  The terminal device 1 determines the type of the serving cell and / or the cell being measured. When a plurality of in-zone cells (primary cells and secondary cells) are set by carrier aggregation, the terminal device 1 is primary when evaluating measurement event conditions for the primary cell among the in-zone cells. The cell may be a cell used for determination. On the other hand, when evaluating the measurement event condition for the secondary cell among the serving cells, the terminal device 1 may use the secondary cell for the determination.

  The cell type is information indicating the size (size, radius) of the cell. For example, the cell type is classified into a large cell (macro cell) and a small cell (small cell). The terminal device 1 determines the cell type based on information indicating whether the cell is a macro cell. Alternatively, the terminal device 1 determines the cell type based on information indicating whether the cell is a small cell. Alternatively, the terminal device 1 determines the cell type based on the physical cell ID. Alternatively, the terminal device 1 determines the cell type based on the frequency band number. The terminal device 1 holds the type of the serving cell and the type of the neighboring cell as internal information and uses it when evaluating the measurement event. Information regarding the size of these cells may be notified by broadcast information, or may be individually notified from the base station apparatus to the terminal apparatus 1.

  Information indicating whether a cell is a macro cell or information indicating whether a cell is a small cell expands the peripheral cell list information indicating a peripheral cell list, and for each cell (or cell group or frequency) in the list. The terminal device 1 may be notified by adding information indicating the cell type.

  In addition, when the information of the cell type of the neighboring cell detected by the terminal device 1 is not held due to reasons such as not being notified from the base station device 2, the detected cell is set to a predetermined cell type (macro cell or (Small cell) may be determined.

  The terminal device 1 can also classify the macro cell and the small cell based on the physical cell ID of the cell to be measured. That is, information for classifying the physical cell ID group 1 indicating the cell group of the macro cell and the physical cell ID group 2 indicating the cell group of the small cell is set from the base station apparatus to the terminal apparatus 1.

  Moreover, the terminal device 1 estimates the moving speed information of the own device when evaluating the measurement event. The moving speed information may be classified into a plurality of levels such as low speed, medium speed, and high speed.

  FIG. 4 is a diagram illustrating cell types of a serving cell (source cell) and a neighboring cell (target cell) in the terminal device 1 that is estimated to have high speed movement information of its own device, and parameters to be adjusted. .

  As shown in FIG. 4, when the estimated movement speed information of the own device is high speed, the terminal device 1 uses a macro cell as the type of the serving cell, and the neighboring cell to be evaluated for the measurement event is a small cell. If it is, the measurement event is evaluated by adjusting the parameters related to the neighboring cells. The parameter adjustment related to the peripheral cell indicates that adjustment is performed on various parameters (offset values) for the set measurement event evaluation. More specifically, the terminal device 1 is a case where the estimated movement speed information of its own device is high, and when the type of one serving cell is a macro cell and the type of a neighboring cell is a small cell, While applying the offset value (Ocp) unique to the serving cell to the reception quality (Mp) of the serving cell, the offset value unique to the neighboring cell with respect to the receiving quality (Mn) of the neighboring cell whose cell type is determined to be a small cell The measurement event evaluation method is changed so that (Ocn) is not applied.

  On the other hand, even if the estimated movement speed information of the own device is high, the terminal device 1 has a case where the type of the serving cell is a macro cell and the neighboring cell to be evaluated for the measurement event is a macro cell. The measurement event condition is evaluated based on the set parameters without adjusting the parameters related to the neighboring cells.

  As a method other than the parameter adjustment illustrated in FIG. 4, for example, the terminal device 1 changes the offset value (Ocp) unique to the serving cell to an offset value specified separately. Alternatively, the terminal device 1 changes the value by applying the designated scaling value to the offset value (Ocp) unique to the serving cell. In this case, the designated scaling value is set so that the reception quality of the serving cell (macro cell) is evaluated as better than the actual one. Alternatively, the terminal device 1 changes the value by applying the designated scaling value to the offset value (Ocn) unique to the neighboring cell. The designated scaling value is set so that the reception quality of the neighboring cell (small cell) is evaluated as being worse than the actual one.

  Returning to FIG. 4, when the estimated movement speed information of the own device is high speed, the terminal device 1 has a small cell as the type of the serving cell, and a neighboring cell to be evaluated for the measurement event is a macro cell. In this case, parameter adjustment related to the serving cell is performed, and the measurement event is evaluated. The parameter adjustment related to the serving cell indicates that adjustment is made to various parameters for measurement event evaluation set in conformity with the small cell arrangement, and the parameter is applied after changing to another value. More specifically, when the type of the serving cell is a small cell and the estimated moving speed information of the own device is high speed, the terminal device 1 receives the reception quality (Mp) of a certain serving cell. The measurement event is evaluated so that the offset value (Ocn) unique to the neighboring cell is not applied to the reception quality (Mn) of the other cell (neighboring cell) while the offset value (Ocn) unique to the neighboring cell is applied. Change the method.

  As a method other than the parameter adjustment illustrated in FIG. 4, for example, the terminal device 1 changes the offset value (Ocn) unique to the neighboring cell to an offset value specified separately. Alternatively, the terminal device 1 changes the value by applying the designated scaling value to the offset value (Ocn) unique to the neighboring cell. In this case, the designated scaling value is set so that the reception quality of the neighboring cell (macro cell) is evaluated as better than the actual one. Alternatively, the terminal device 1 changes the value by applying the designated scaling value to the offset value (Ocp) unique to the serving cell. The designated scaling value is set so that the reception quality of the serving cell (small cell) is evaluated as being worse than the actual one.

  On the other hand, even if the estimated movement speed information of the own device is high, the terminal device 1 has a small cell as the type of the serving cell and the small cell is a neighboring cell to be evaluated for the measurement event. In some cases, the parameter adjustment relating to the neighboring cell is not performed, and the measurement event condition is evaluated based on the set parameter.

  Note that the terminal device 1 is not limited to the case where the moving speed information is high speed, and the terminal device 1 performs parameter adjustment on the serving cell when the moving speed information is other than low speed (that is, when the moving speed information is high speed or medium speed). An evaluation may be performed.

  The base station device 2 is configured to perform the following measurement event processing when evaluating measurement events for neighboring cells during communication with a certain terminal device 1. The base station apparatus 2 notifies the terminal apparatus 1 whether or not adjustment of the parameter value used for the measurement event condition is necessary. For example, when the base station apparatus 2 sets the measurement setting in the terminal apparatus 1, the base station apparatus 2 may explicitly set additional information indicating the start of adjustment of the parameter value used for the measurement event condition in the measurement setting. The additional information may be information indicated by 1 bit (for example, True / False), or may be information indicating setup. Alternatively, when the base station apparatus 2 sets the measurement setting in the terminal apparatus 1, the base station apparatus 2 sets parameter information used implicitly for the measurement event condition to the terminal apparatus 1 by setting information that can determine the small cell. You may notify that adjustment is required.

  By configuring in this way, the terminal device 1 can perform efficient measurement corresponding to the heterogeneous network by changing and applying parameters used for measurement event evaluation based on the cell type. The cell to report to the base station apparatus 2 is appropriately determined. That is, when the terminal device 1 is in the macro cell, the establishment of the measurement event condition for the small cell is suppressed, and the handover failure probability due to handover from the macro cell to the small cell during high-speed movement is reduced. Can do. Further, when the terminal device 1 is located in the small cell, the establishment of the measurement event condition for the macro cell is promoted, and the handover failure probability due to handover from the small cell to the macro cell during high-speed movement is reduced. Can do.

  The terminal device 1 may be configured as follows. For example, when the terminal device 1 evaluates the measurement event condition, the moving speed information estimated by the terminal device 1 is high-speed, and the neighboring cell to be evaluated is a different cell type from the serving cell. The cell-specific offset value of a cell whose cell type is a small cell may be configured to perform parameter adjustment so that it is not used for evaluation of measurement event conditions. In other words, when the terminal device 1 evaluates the conditions of the measurement event, if the movement speed information estimated by the terminal device 1 is not high speed, or the neighboring cell to be evaluated is the same cell as the serving cell In the case of type, parameter adjustment related to measurement event evaluation is not performed.

  The terminal device 1 according to the present embodiment changes the parameter set according to the state of the device itself and applies the measurement event condition to a network (heterogeneous network) in which cells other than the macro cell are arranged. It becomes possible. In addition, the base station device 2 of the present embodiment transmits information indicating whether or not to change the parameter to the terminal device 1, and causes the terminal device 1 to apply the changed parameter of the measurement event condition. It becomes possible to make the measurement event condition correspond to a network in which cells other than the macro cell are arranged.

  According to the first embodiment, the terminal device 1 changes the parameter according to the state of its own device based on the information set from the base station device 2 and applies the parameter to the base station device 2 as a handover destination. It is possible to reduce the possibility of reporting a cell that is not suitable as a cell. In addition, since the base station apparatus 2 can cause the terminal apparatus 1 to perform efficient measurement event condition evaluation based on the environment of the surrounding cells of the local station apparatus, the terminal apparatus 1 can It is possible to reduce the possibility of reporting a cell that is not suitable as a cell. Therefore, the probability of successful handover when the terminal device 1 accesses the handover destination cell is improved, and the communication quality can be improved.

<Second Embodiment>
A second embodiment of the present invention will be described below.

  As a measurement event processing method according to the second embodiment of the present invention, a method using an additional (new) measurement event condition will be described. The terminal device 1 starts the following measurement event processing when evaluating a measurement event for a neighboring cell during communication with a certain base station device 2.

  When the neighboring cell is a small cell, the terminal device 1 evaluates whether or not the reception quality of the neighboring cell exceeds the reception quality of one serving cell when evaluating the reception quality of the neighboring cell. Both the condition and the second condition for evaluating whether the reception quality of the serving cell falls below a certain threshold value are used.

  The reception quality of neighboring cells is the result of applying all the cell-specific offset values, frequency-specific offset values, hysteresis, and measurement event-specific offset values set for the measurement results obtained by measuring the neighboring cells. To be interpreted. Similarly, the reception quality of the serving cell refers to the cell-specific offset value, frequency-specific offset value, measurement event-specific offset value, and hysteresis set for the measurement result obtained by measuring the serving cell. Are all applied.

  Regarding the first condition, when the reception quality of the neighboring cell is Mn1 and the reception quality of the serving cell is Mp1, the terminal device 1 continuously satisfies Mn1> Mp1 as indicated by the measurement event evaluation time (TTT). Evaluate whether or not. The measurement result of Mn1 is indicated by RSRP or RSRQ.

  Regarding the second condition, when the reception quality of the serving cell is Mp2 and the threshold value for Mp2 is TH, the terminal device 1 continuously satisfies Mp2 <TH for the time indicated by the measurement event evaluation time (TTT). Evaluate whether or not. The measurement result of Mp2 is indicated by RSRQ.

  Moreover, another form may be sufficient as a 2nd condition. For example, for the second condition, when the reception quality of the neighboring cell is Mn2 and the threshold value for Mn2 is TH, the terminal device 1 continuously satisfies Mn2> TH as indicated by the measurement event evaluation time (TTT). Evaluate whether it has become. The measurement result of Mn2 is indicated by RSRQ. By adding the second condition, the terminal device 1 can evaluate not only the magnitude of the received power of the downlink reference signal between cells but also the received quality of the actual cell, and the received power is Handover to a cell with good but poor quality will be suppressed.

  The terminal device 1 determines that the measurement event condition is satisfied when both the first condition and the second condition are satisfied, and reports the establishment of the measurement event to the base station device 2. In addition, the terminal device 1 determines that the measurement event condition is not established when either the first condition or the second condition does not satisfy the condition, and notifies the base station device 2 that the measurement event is not established. Report to

  The measurement event condition including the first condition and the second condition is applied when the cell type of the neighboring cell is a small cell. Alternatively, the measurement event condition including the first condition and the second condition is applied when the cell type of the neighboring cell is a small cell and the moving speed information of the terminal device 1 is high speed. Alternatively, the measurement event condition including the first condition and the second condition is applied when the cell type of the serving cell is a macro cell. Alternatively, the measurement event condition including the first condition and the second condition is applied when the cell type of the serving cell is a macro cell and the moving speed information of the terminal device 1 is high speed. Alternatively, the measurement event condition including the first condition and the second condition is applied when the cell type of the serving cell and the neighboring cell are different. Alternatively, the measurement event condition including the first condition and the fourth condition is applied when the cell types of the serving cell and the neighboring cell are different and the moving speed information of the terminal device 1 is high speed. .

  Further, when the serving cell is a small cell, the terminal device 1 evaluates whether the reception quality of the neighboring cell exceeds the receiving quality of one serving cell when evaluating the reception quality of the neighboring cell. Both the third condition and the fourth condition for evaluating whether the reception quality of the neighboring cell exceeds a certain threshold value are used.

  Regarding the third condition, when the reception quality of the neighboring cell is Mn3 and the reception quality of the serving cell is Mp3, the terminal device 1 continuously satisfies Mn3> Mp3 as indicated by the measurement event evaluation time (TTT). Evaluate whether or not. The measurement result of Mn3 is indicated by RSRP or RSRQ.

  Regarding the fourth condition, when the reception quality of the neighboring cell is Mn4 and the threshold value for Mn4 is TH, the terminal device 1 has Mn4> TH continuously for the time indicated by the measurement event evaluation time (TTT). Evaluate whether. The measurement result of Mn4 is indicated by RSRQ.

  Further, the fourth condition may be another form. For example, for the fourth condition, when the reception quality of the serving cell is Mp4 and the threshold value for Mp4 is TH, the terminal device 1 continuously receives Mp4 <TH for the time indicated by the measurement event evaluation time (TTT). Evaluate whether or not. The measurement result of Mp4 is indicated by RSRQ. By adding the fourth condition, the terminal device 1 can evaluate not only the magnitude of the received power of the downlink reference signal between cells but also the received quality of the actual cell, and the received power is Handover to a cell with good but poor quality will be suppressed.

  The terminal device 1 determines that the measurement event condition is satisfied when both the third condition and the fourth condition are satisfied, and reports the establishment of the measurement event to the base station device 2. In addition, the terminal device 1 determines that the measurement event condition is not established when either the third condition or the fourth condition does not satisfy the condition, and notifies the base station device 2 that the measurement event is not established. Report to

  The measurement event condition including the third condition and the fourth condition is applied when the cell type of the serving cell is a small cell. Alternatively, the measurement event condition including the third condition and the fourth condition is applied when the cell type of the serving cell is a small cell and the moving speed information of the terminal device 1 is high speed. Alternatively, the measurement event condition including the third condition and the fourth condition is applied when the cell type of the neighboring cell is a macro cell. Alternatively, the measurement event condition including the third condition and the fourth condition is applied when the cell type of the neighboring cell is a macro cell and the moving speed information of the terminal device 1 is high speed. Alternatively, the measurement event condition including the third condition and the fourth condition is applied when the cell type of the serving cell and the neighboring cell are different. Alternatively, the measurement event condition including the third condition and the fourth condition is applied when the cell types of the serving cell and the neighboring cell are different and the moving speed information of the terminal device 1 is high speed. .

  In the terminal device 1, the first condition and the second condition, or the third condition and the fourth condition are set in the reporting configuration information (Reporting configuration) of the measurement setting received from the base station device 2. In the case, the evaluation of the measurement event condition is started based on the setting.

  By configuring in this way, the terminal device 1 can evaluate the measurement quality using the additional measurement event condition based on the cell type, so that the terminal device 1 performs an efficient measurement corresponding to the heterogeneous network. The cell to report to the base station apparatus 2 is appropriately determined. That is, when the terminal device 1 is located in the macro cell, the establishment of the measurement event condition for the small cell with poor reception quality is suppressed, and the handover failure probability due to handover from the macro cell to the small cell during high-speed movement Can be reduced. Further, when the terminal apparatus 1 is located in a small cell, establishment of a measurement event condition for a macro cell with poor reception quality is promoted, and handover failure probability due to handover from the small cell to the macro cell during high-speed movement Can be reduced.

  The terminal device 1 of the present embodiment can make the measurement event condition correspond to a network (heterogeneous network) in which cells other than the macro cell are arranged by using an additional measurement event condition according to the state of the own device. It becomes. In addition, the base station device 2 according to the present embodiment transmits information related to the additional measurement event condition to the terminal device 1 in the measurement setting so that the measurement event condition corresponds to a network in which cells other than the macro cell are arranged. It becomes possible.

  According to the second embodiment, the terminal device 1 evaluates the additional measurement event condition according to the state of the own device based on the information set from the base station device 2, thereby allowing the terminal device 1 to The possibility of reporting a cell that is not suitable as a handover destination cell can be reduced. In addition, since the base station apparatus 2 can cause the terminal apparatus 1 to perform efficient measurement event condition evaluation based on the environment of the surrounding cells of the local station apparatus, the terminal apparatus 1 can It is possible to reduce the possibility of reporting a cell that is not suitable as a cell. Therefore, the probability of successful handover when the terminal device 1 accesses the handover destination cell is improved, and the communication quality can be improved.

  The embodiment described above is merely an example, and can be realized using various modifications and replacement examples. For example, this uplink transmission scheme can be applied to both communication systems of the FDD (frequency division duplex) scheme and the TDD (time division duplex) scheme. In addition, as the downlink measurement value, path loss or other measurement values (SIR, SINR, RSRP, RSRQ, RSSI, BLER) may be used instead, or a combination of these measurement values may be used. Is also possible. Further, the names of the parameters shown in the embodiments are called for convenience of explanation, and even if the parameter names actually applied and the parameter names of the embodiments of the present invention are different, the present invention It does not affect the gist of the invention claimed in the embodiment.

  Further, the terminal device 1 of the above-described embodiment is not limited to a portable or movable mobile station device, but a stationary or non-movable electronic device installed indoors or outdoors, such as an AV device, a kitchen device, It can also be applied to cleaning / washing equipment, air conditioning equipment, office equipment, vending machines, other life equipment, measuring equipment, and in-vehicle devices. The terminal device is also referred to as a user terminal, a mobile station device, a communication terminal, a mobile device, a terminal, a UE (User Equipment), and an MS (Mobile Station). The base station apparatus is also referred to as a radio base station apparatus, a base station, a radio base station, a fixed station, an NB (Node-B), an eNB (evolved Node-B), a BTS (Base Transceiver Station), and a BS (Base Station). .

  In addition, for convenience of explanation, the terminal device 1 and the base station device 2 of the embodiment have been described using functional block diagrams, but the functions of each part of the terminal device 1 and the base station device 2 or some of these functions are described. The method or algorithm steps for implementing may be directly embodied by hardware, software modules executed by a processor, or a combination of the two. If implemented by software, the functions may be maintained or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media includes both communication media and computer recording media including media that facilitate carrying a computer program from one place to another.

  One or more instructions or codes are recorded on a computer-readable recording medium, and one or more instructions or codes recorded on the recording medium are read into a computer system and executed, thereby executing the terminal device 1 or the base. The station device 2 may be controlled. Here, the “computer system” includes an OS and hardware such as peripheral devices.

  The operations described in the embodiments of the present invention may be realized by a program. A program that operates in the terminal device 1 and the base station device 2 according to each embodiment of the present invention is a program that controls a CPU or the like (a computer is installed) so as to realize the functions of the above-described embodiments according to each embodiment of the present invention. Program to function). Information handled by these devices is temporarily stored in the RAM at the time of processing, then stored in various ROMs and HDDs, read out by the CPU, and corrected and written as necessary. In addition, by executing the program, not only the functions of the above-described embodiment are realized, but also the processing of the present invention is performed by processing in cooperation with the operating system or other application programs based on the instructions of the program. The functions of the embodiments may be realized.

  The “computer-readable recording medium” refers to a semiconductor medium (eg, RAM, nonvolatile memory card, etc.), an optical recording medium (eg, DVD, MO, MD, CD, BD, etc.), a magnetic recording medium (eg, , A magnetic tape, a flexible disk, etc.) and a storage device such as a disk unit built in a computer system. Furthermore, the “computer-readable recording medium” means that a program is dynamically held for a short time, like a communication line when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In this case, it is intended to include those that hold a program for a certain period of time, such as a volatile memory inside a computer system serving as a server or a client in that case.

  Further, the program may be for realizing a part of the above-described functions, and further, may be realized by combining the above-described functions with a program already recorded in a computer system. good.

  In addition, each functional block or various features of the terminal device 1 and the base station device 2 used in each of the above embodiments is a general-purpose processor, a digital signal processor designed to execute the functions described in this specification. (DSP), application specific or general purpose integrated circuit (ASIC), field programmable gate array signal (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or combinations thereof It can be implemented or implemented by something. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The general-purpose processor or each circuit described above may be configured by a digital circuit or an analog circuit.

  The processor may also be implemented as a combination of computing devices. For example, a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors connected to a DSP core, or a combination of other such configurations.

  As mentioned above, although embodiment of this invention was explained in full detail based on the specific example, it is clear that the meaning of each embodiment of this invention and a claim are not limited to these specific examples. In other words, the description in the present specification is for illustrative purposes and does not limit the embodiments of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Terminal device 2 ... Base station apparatus 101, 201 ... Reception part 102, 202 ... Demodulation part 103, 203 ... Decoding part 104 ... Measurement processing part 105, 204 ... Control part 106 ... Uplink buffer control part 107, 205 ... Code Units 108, 206, modulation units 109, 207, transmission unit 110, uplink radio resource request control unit 111, random access control unit 112, 208, upper layer 209, network signal transmission / reception unit 301, neighboring cell information management unit 302, measurement Parameter management unit 303 ... measurement event evaluation unit

Claims (15)

A terminal device that communicates with a base station device,
When evaluating a measurement event condition for comparing measurement quality of cells, the measurement event condition is changed based on the moving speed information estimated by the terminal device and the type of the cell, and the changed measurement event condition is evaluated. A terminal device reporting a result to the base station device. A terminal device that communicates with a base station device,
Information indicating whether or not to apply an additional measurement event condition is received, and when evaluating the measurement event condition for comparing the measurement quality of the cell, the mobile speed information estimated by the terminal device and the cell type are The terminal device characterized in that the additional measurement event condition is evaluated based on the terminal device.   The terminal apparatus according to claim 2, wherein the additional measurement event condition includes a first condition and a second condition that are different from each other.   The first condition is to evaluate whether or not the reception quality of the neighboring cell to which the offset value is added exceeds the reception quality of the serving cell to which the offset value is added continuously for the time indicated by the measurement event evaluation time. The terminal device according to claim 3.   The first condition is to evaluate whether or not the reception quality of the neighboring cell to which the offset value is added is lower than the reception quality of the serving cell to which the offset value is added continuously for the time indicated by the measurement event evaluation time. The terminal device according to claim 3.   The second condition is characterized in that it is evaluated whether or not the reception quality of a serving cell to which an offset value is added has exceeded a threshold value related to the serving cell for a time continuously indicated by a measurement event evaluation time. Item 4. The terminal device according to Item 3.   The second condition is characterized in that it is evaluated whether or not the reception quality of a neighboring cell to which an offset value has been added has continuously exceeded a threshold related to the neighboring cell for a time indicated by a measurement event evaluation time. The terminal device described in 1. A base station device that communicates with a terminal device,
Whether or not to change the measurement event condition based on the moving speed information estimated by the terminal device and the cell type when starting evaluation of the measurement event condition for comparing the measurement quality of the cell by the terminal device A base station apparatus which sets and notifies information indicating A base station device that communicates with a terminal device,
Whether to apply an additional measurement event condition based on the moving speed information estimated by the terminal device and the type of the cell when starting evaluation of the measurement event condition for comparing the measurement quality of the cell by the terminal device A base station apparatus characterized in that information indicating such is set and notified. A communication system in which a base station device and a terminal device communicate with each other,
The base station device, when starting evaluation of measurement event conditions for comparing measurement quality of cells by the terminal device, based on the moving speed information estimated by the terminal device and the type of the cell Set information indicating whether or not to change
The terminal device receives information indicating whether to change the measurement event condition,
The measurement event condition is changed based on information indicating whether to change the measurement event condition, movement speed information estimated by the terminal device, and the type of the cell, and the changed measurement event condition An evaluation result is reported to the base station apparatus. A communication system in which a base station device and a terminal device communicate with each other,
When the base station apparatus starts evaluation of measurement event conditions for comparing measurement quality of cells by the terminal apparatus, the base station apparatus adds the measurement event based on the moving speed information estimated by the terminal apparatus and the type of the cell. Set and notify information indicating whether the condition is applied,
The terminal device receives information indicating whether to apply the additional measurement event condition;
The additional measurement event condition is evaluated based on information indicating whether or not to apply the measurement event condition, movement speed information estimated by the terminal device, and a type of the cell. Communications system. A method for measuring a terminal device communicating with a base station device,
A step of changing the measurement event condition based on the moving speed information estimated by the terminal device and the type of the cell when evaluating the measurement event condition for comparing the measurement quality of the cell; and the changed measurement event condition A measurement method comprising: reporting the evaluation result to the base station apparatus. A method for measuring a terminal device communicating with a base station device,
The step of receiving information indicating whether or not to apply an additional measurement event condition and the evaluation of the measurement event condition for comparing the measurement quality of the cell and the movement speed information estimated by the terminal device and the cell A measurement method comprising the step of evaluating the additional measurement event condition based on a type. An integrated circuit mounted on a terminal device that communicates with a base station device,
A function of changing the measurement event condition based on the moving speed information estimated by the terminal device and the type of the cell when evaluating the measurement event condition for comparing the measurement quality of the cell, and the changed measurement event condition An integrated circuit characterized by causing the terminal device to exhibit a function of reporting the evaluation result to the base station device. An integrated circuit mounted on a terminal device that communicates with a base station device,
The function of receiving information indicating whether or not to apply an additional measurement event condition, and the evaluation of the measurement event condition for comparing the measurement quality of the cell, the movement speed information estimated by the terminal device and the cell An integrated circuit characterized by causing the terminal device to exhibit a function of evaluating the additional measurement event condition based on a type.