JP2012070271A - Terminal selection method, network device and wireless terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently obtain measurement results necessary for optimization.SOLUTION: A terminal selection method for selecting a wireless terminal used for an MDT in a mobile communication system in which a tracking area is formed by one cell or a plurality of cells includes the step of acquiring movement frequency information showing a frequency that a wireless terminal UE changes existing cell or existing tracking area by a maintenance monitoring device OAM, and the step of determining whether the wireless terminal UE should be used for the MDT or not by the maintenance monitoring device OAM, based on the movement frequency information acquired in the acquiring step.

Description

  The present invention relates to a terminal selection method, a network device, and a wireless terminal for selecting a wireless terminal used for MDT.

  In a mobile communication system, when a building is constructed around a radio base station or the installation status of the base stations around the radio base station changes, the radio environment related to the radio base station changes. For this reason, conventionally, a drive test in which a measurement vehicle equipped with measurement equipment is used by an operator to measure a wireless environment and collect measurement results and position information is performed.

  Such measurement and collection can contribute to optimization of the coverage of a radio base station, for example, but there are problems that the number of man-hours and the cost are high. Therefore, 3GPP (3rd Generation Partnership Project), a standardization project for mobile communication systems, formulates specifications for MDT (Minimization of Drive Test), a technology that automates measurement and collection using wireless terminals owned by users. (See Non-Patent Documents 1 and 2).

3GPP TR 36.805 V9.0.0 “Study on Minimization of drive-tests in Next Generation Networks”, 2009-12 3GPP TS 37.320 v0.7.0, “Radio measurement collection for Minimization of Drive Tests (MDT)”, 2010-07

  By the way, as a terminal selection method for selecting a wireless terminal to be used for MDT, a network device (for example, a maintenance monitoring device or a wireless base station) acquires information indicating the capability of the wireless terminal, and based on the information indicating the capability. It is assumed that it is determined whether to use the wireless terminal for MDT.

  However, in this method, there is a possibility that a radio terminal that moves less frequently is selected as a radio terminal used for MDT. Even if such a wireless terminal is used for MDT, only the measurement result at the same position can be obtained from the wireless terminal.

  Therefore, the terminal selection method for determining whether to use the wireless terminal for MDT based on the information indicating the capability of the wireless terminal cannot obtain measurement results over a wide range, and the measurement results necessary for optimization May not be sufficiently obtained.

  Therefore, an object of the present invention is to provide a terminal selection method, a network device, and a wireless terminal that can sufficiently obtain measurement results necessary for optimization.

  In order to solve the above-described problems, the present invention has the following features. First, the terminal selection method according to the present invention is characterized in that a terminal selection method for selecting a radio terminal to be used for MDT in a mobile communication system (mobile communication system 1) in which a tracking area is configured by one or a plurality of cells. A network device (maintenance monitoring device OAM or radio base station eNB) acquires movement frequency information indicating a frequency at which a radio terminal (radio terminal UE) switches a cell or a tracking area in which the network device is located; The network device includes a step of determining whether to use the wireless terminal for MDT based on the movement frequency information acquired in the acquiring step.

  According to such a feature, since the wireless terminal selects the wireless terminal to be used for MDT according to the frequency at which the wireless terminal switches the cell or the tracking area in which the wireless terminal is located, that is, the moving frequency of the wireless terminal, a wide range of measurement results And measurement results necessary for optimization can be sufficiently obtained.

  Another feature of the terminal selection method according to the present invention is that, in the terminal selection method according to the above feature, the wireless terminal or the location registration server (home location register HLR) transmits a message including the movement frequency information. And the network device further includes a step of receiving the message, and the acquiring step is to acquire the movement frequency information included in the message received in the receiving step.

  Another feature of the terminal selection method according to the present invention is that the wireless terminal or the location registration server (home location register HLR) is used for generating the movement frequency information in the terminal selection method according to the above feature. The network device further includes a step of receiving the message, and in the obtaining step, from the generation information included in the message received in the receiving step The gist is to obtain the movement frequency information.

  Another feature of the terminal selection method according to the present invention is that, in the terminal selection method according to the above feature, in the step of determining, if the frequency indicated by the movement frequency information is lower than a predetermined degree, the wireless terminal The gist is to decide not to use for MDT.

  Another feature of the terminal selection method according to the present invention is that in the terminal selection method according to the above feature, in the obtaining step, the movement frequency information for each time zone is obtained, and in the determining step, for each time zone. The gist is to determine whether to use the wireless terminal for MDT based on the movement frequency information.

  Another feature of the terminal selection method according to the present invention is that, in the terminal selection method according to the above feature, when the network device determines to use the wireless terminal for MDT in the determining step, the MDT measurement configuration is The gist of the present invention is to further include a step of transmitting information for setting to the wireless terminal.

  The network device according to the present invention is characterized by a network device (maintenance monitoring device OAM) that can select a wireless terminal used for MDT in a mobile communication system (mobile communication system 1) in which a tracking area is configured by one or a plurality of cells. Or an acquisition unit (movement frequency information acquisition unit 331 or 141) that acquires the movement frequency information indicating the frequency at which the wireless terminal (wireless terminal UE) switches the cell or the tracking area in which it is located. And a determination unit (MDT use terminal determination unit 332 or 142) that determines whether or not to use the wireless terminal for MDT based on the movement frequency information acquired by the acquisition unit. And

  A feature of a radio terminal according to the present invention is a radio terminal (radio terminal UE) that can be used for MDT in a mobile communication system (mobile communication system 1) in which a tracking area is configured by one or a plurality of cells. A transmission unit (radio communication unit 210) that transmits to the radio base station a message including movement frequency information indicating the frequency of switching between the serving cell or the tracking area in which the cell is located, or generation information used to generate the movement frequency information. It is a summary to provide.

  ADVANTAGE OF THE INVENTION According to this invention, the terminal selection method, network apparatus, and radio | wireless terminal which can fully obtain the measurement result required for optimization can be provided.

It is a figure which shows the whole schematic structure of the mobile communication system which concerns on 1st Embodiment-3rd Embodiment. It is a block diagram which shows the structure of the radio | wireless terminal which concerns on 1st Embodiment. It is a block diagram which shows the structure of the maintenance monitoring apparatus which concerns on 1st Embodiment. It is a sequence diagram which shows the terminal selection method which concerns on 1st Embodiment. It is a sequence diagram which shows the terminal selection method which concerns on the modification 2 of 1st Embodiment. It is a sequence diagram which shows the terminal selection method which concerns on the modification 3 of 1st Embodiment. It is a sequence diagram which shows the terminal selection method which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the wireless base station which concerns on 3rd Embodiment. It is a sequence diagram which shows the terminal selection method which concerns on 3rd Embodiment. It is a sequence diagram which shows the terminal selection method which concerns on the modification 2 of 3rd Embodiment. It is a sequence diagram which shows the terminal selection method which concerns on the modification 3 of 3rd Embodiment.

  The first to third embodiments of the present invention and other embodiments will be described with reference to the drawings. In the drawings in the following embodiments, the same or similar parts are denoted by the same or similar reference numerals.

  In the following description, a mobile communication system configured based on LTE (Long Term Evolution) -Advanced, for which specifications have been formulated in 3GPP, will be mainly described, but configured based on W-CDMA (Wideband Code Division Multiple Access). It should be noted that the present invention can also be applied to a mobile communication system.

  A terminal selection method according to each embodiment is a terminal selection method for selecting a radio terminal UE to be used for MDT in a mobile communication system in which a tracking area is configured by one or a plurality of cells. A step in which the monitoring apparatus OAM or the radio base station eNB) acquires movement frequency information indicating the frequency with which the radio terminal UE switches the cell or the tracking area in which it is located; and the network apparatus (the maintenance monitoring apparatus OAM or the radio base station) eNB) determining whether or not to use the radio terminal UE for MDT based on the movement frequency information acquired in the acquiring step.

(1) First Embodiment Hereinafter, regarding the first embodiment, (1.1) overall schematic configuration, (1.2) configuration of wireless terminal, (1.3) configuration of maintenance monitoring device, (1.4) (1.5) Effect of the first embodiment, (1.6) Modification 1 of the first embodiment, (1.7) Modification 2 of the first embodiment, (1.8) First Description will be made in the order of Modification 3 of the embodiment.

(1.1) Overall Schematic Configuration FIG. 1 is a diagram showing an overall schematic configuration of the mobile communication system 1 according to the first embodiment.

  As shown in FIG. 1, a mobile communication system 1 includes a radio terminal UE (User Equipment), a plurality of radio base stations eNB (evolved Node-B), a maintenance monitoring device OAM (Operation and Maintenance), and a plurality of mobility management devices MME. (Mobility Management Entity) / Gateway device S-GW (Serving Gateway), and home location register HLR. In the following, the E-UTRAN, the maintenance monitoring device OAM, and the home location register HLR are collectively referred to as a “network”.

  A plurality of radio base stations constitute an E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) which is a radio access network. Each of the plurality of radio base stations eNB forms a cell that is a communication area that should provide a service to the radio terminal UE. The radio terminal UE is a radio communication device possessed by a user and is also referred to as a user device.

  A tracking area is constituted by one or a plurality of cells. The home location register HLR manages the position of the radio terminal UE in units of tracking areas. When the radio terminal UE crosses the boundary of the tracking area, that is, when moving to a tracking area having a different tracking area identifier, the radio terminal UE notifies the network of an update of the tracking area. By managing the position of the radio terminal UE in units of tracking areas in this way, a paging message for call connection can be transmitted in units of tracking areas.

  Each adjacent radio base station eNB can communicate with each other via an X2 interface which is a logical communication path providing inter-base station communication. Each of the plurality of radio base stations eNB can communicate with EPC (Evolved Packet Core), specifically, MME (Mobility Management Entity) / S-GW (Serving Gateway) via the S1 interface. Each radio base station eNB can communicate with a maintenance monitoring device OAM operated by an operator.

  The mobile communication system 1 supports MDT. In MDT, an immediate report type (referred to as Immediate MDT) and a recording type (referred to as Logged MDT) are defined. In the Immediate MDT, a wireless terminal in a connected state (that is, during communication execution) measures a wireless environment and reports a measurement result and position information to a network. Logged MDT measures the wireless environment when, for example, a wireless terminal in an idle state (that is, in standby) satisfies a set condition, and logs data including a measurement result, location information, and a time stamp to a network later. Hold for reporting. In the current specification, it is defined that the Logged MDT is executed by the idle radio terminal UE.

(1.2) Configuration of Radio Terminal FIG. 2 is a block diagram showing a configuration of the radio terminal UE according to the first embodiment.

  As illustrated in FIG. 2, the radio terminal UE includes an antenna 201, a radio communication unit 210, a user interface unit 220, a GPS receiver 230, a battery 240, a storage unit 250, and a control unit 260. However, the radio terminal UE may not have the GPS receiver 230.

  The antenna 201 is used for transmission / reception of a radio signal. The wireless communication unit 210 is configured using, for example, a radio frequency (RF) circuit, a baseband (BB) circuit, and the like, and transmits and receives a wireless signal via the antenna 201. The wireless communication unit 210 also modulates the transmission signal and demodulates the reception signal. The user interface unit 220 is a display, a button, or the like that functions as an interface with the user. The battery 240 stores electric power supplied to each block of the radio terminal UE. The storage unit 250 is configured using, for example, a memory, and stores various types of information used for controlling the radio terminal UE and the like. The control unit 260 is configured using, for example, a CPU, and controls various functions provided in the radio terminal UE.

  The control unit 260 includes a movement state management unit 261, an information generation unit 262, and an MDT processing unit 263.

  The movement state management unit 261 manages the movement state of the terminal itself. Specifically, the movement state management unit 261 records and manages the time (hereinafter, cell switching time) when the cell in which the terminal is located is switched. Alternatively, the movement state management unit 261 counts the number of times the cell where the terminal is located is switched after starting a timer for measuring a predetermined time, and stops counting when the timer expires. In addition, the process which switches the cell in which radio | wireless terminal UE exists in an idle state is called cell reselection, and the process which switches the cell in which radio terminal UE exists in a connected state is called a hand-over.

  When there is a request from the network, the information generation unit 262 uses the information managed by the movement state management unit 261 to generate movement frequency information indicating the frequency with which the own terminal switches the cell in the area. The frequency at which the own terminal switches the cell in which it is located is, for example, the number of cell switching times per day, that is, the number of cell reselections and handover cells per day. When the movement state management unit 261 manages the cell switching time, the information generation unit 262 obtains the number of cell switching per day from the cell switching time corresponding to one day, and moves the cell switching number or its index. Generate as frequency information. On the other hand, when the movement state management unit 261 counts the number of cell switching times according to the timer, the information generation unit 262 obtains the number of cell switching times during the timer period corresponding to one day, and An index is generated as movement frequency information.

  The information generation unit 262 outputs a UE MDT_Information Report message including the generated movement frequency information and a terminal identifier for identifying the terminal itself to the wireless communication unit 210. The radio communication unit 210 transmits the UE MDT_Information Report message to the radio base station eNB.

  When the wireless communication unit 210 receives an MDT Configuration message including a measurement configuration composed of measurement parameters in MDT, the MDT processing unit 263 sets the measurement configuration included in the MDT Configuration message in its own terminal and sets the measurement The wireless environment is measured according to the configuration, and MDT data including a measurement result, position information, and a time stamp is recorded. After shifting from the idle state to the connected state, the MDT processing unit 263 reports the recorded MDT data to the network in response to a request from the network.

  In the Logged MDT, the measurement configuration consists of measurement target (measurements to be logged), measurement trigger (triggering of logging event), measurement time (total duration of logging), absolute time (network absolute time stamp), and measurement area. (Measurements area). However, the measurement area may not be included in the measurement configuration. The measurement target is, for example, a frequency band to be measured, and the MDT processing unit 263 measures the reference signal reception power (RSRP) and the reference signal reception quality (RSRQ) for the measurement target frequency band. The measurement trigger is, for example, a periodic downlink pilot signal strength measurement trigger, and the measurement interval can be set in this region. The radio terminal UE performs measurement when the timer corresponding to the set measurement interval expires. The location information includes an ECGI (E-UTRAN Cell Global Identifier) of the serving cell. When the radio terminal UE has a positioning function, the location information further includes GNSS (Global Navigation Satellite System) location information. On the other hand, when the radio terminal UE does not have a positioning function, the location information further includes an RF (Radio frequency) fingerprint related to a reception state from a neighboring cell.

(1.3) Configuration of Maintenance Monitoring Device FIG. 3 is a block diagram showing the configuration of the maintenance monitoring device OAM according to the first embodiment.

  As illustrated in FIG. 3, the maintenance monitoring device OAM includes a network communication unit 310, a storage unit 320, and a control unit 330.

  The network communication unit 310 communicates with the radio base station eNB and the home location register HLR. The storage unit 320 is configured using, for example, a memory, and stores various types of information used for controlling the maintenance monitoring device OAM. The control unit 330 is configured using, for example, a CPU, and controls various functions provided in the maintenance monitoring device OAM.

  The control unit 330 includes a movement frequency information acquisition unit 331, an MDT use terminal determination unit 332, and an MDT control unit 333.

  When the start of MDT is determined, the movement frequency information acquisition unit 331 controls the network communication unit 310 to transmit a UE MDT_Information Request message for acquiring movement frequency information to the radio base station eNB. When the network communication unit 310 receives the UE MDT_Information Report message after transmitting the UE MDT_Information Request message, the movement frequency information acquisition unit 331 acquires the movement frequency information and the terminal identifier included in the received UE MDT_Information Report message.

  Whether or not the MDT using terminal determination unit 332 uses the radio terminal UE that is the transmission source of the UE MDT_Information Report message, which is indicated by the terminal identifier, for MDT, based on the movement frequency information acquired by the movement frequency information acquisition unit 331. To decide. As a specific example, in the case of creating a coverage map, the MDT using terminal determining unit 332 uses the radio terminal UE for MDT when the frequency indicated by the movement frequency information is lower than a predetermined degree. If the frequency indicated by the movement frequency information is greater than or equal to a predetermined level, it is determined that the radio terminal UE is used for MDT. For example, the MDT using terminal determining unit 332 determines that a radio terminal UE having a cell switching frequency of less than N times per day is not used for MDT, and the radio terminal UE having a cell switching frequency of N times or more per day. Is determined to be used for MDT.

  The MDT control unit 333 designates the measurement configuration for the radio base station eNB to which the radio terminal UE determined to be used for MDT is connected (that is, the radio base station eNB that has transferred the UE MDT_Information Report message) Send a send request. The transmission request includes the terminal identifier. Further, when MDT data (measurement results and position information) is reported from the radio terminal UE via the radio base station eNB, the MDT control unit 333 accumulates the reported MDT data. The accumulated MDT data is used, for example, for optimization of E-UTRAN.

(1.4) Terminal Selection Method FIG. 4 is a sequence diagram showing a terminal selection method according to the first embodiment. In the terminal selection method according to the first embodiment, the radio terminal UE transmits a message including movement frequency information, the maintenance monitoring apparatus OAM (network apparatus) receives a message including movement frequency information, and The maintenance monitoring device OAM (network device) includes a step of acquiring movement frequency information included in the message received in the receiving step.

  As illustrated in FIG. 4, when the start of MDT is determined in step S101, the maintenance monitoring apparatus OAM transmits a UE MDT_Information Request message for acquiring movement frequency information to at least one radio configuring the E-UTRAN. It transmits to the base station eNB. The radio base station eNB receives the UE MDT_Information Request message.

  In step S102, the radio base station eNB transmits a UE MDT_Information Request message for acquiring movement frequency information to the radio terminal UE connected to the own station. The radio terminal UE receives a UE MDT_Information Request message.

  In step S103, the radio terminal UE generates movement frequency information.

  In step S104, the radio terminal UE transmits a UE MDT_Information Report message including the generated movement frequency information and a terminal identifier for identifying the own terminal to the radio base station eNB. The radio base station eNB receives the UE MDT_Information Report message.

  In step S105, the radio base station eNB transfers the UE MDT_Information Report message received from the radio terminal UE to the maintenance monitoring apparatus OAM. The maintenance monitoring device OAM receives the UE MDT_Information Report message.

  In step S106, the maintenance monitoring apparatus OAM acquires the movement frequency information and the terminal identifier included in the received UE MDT_Information Report message, and transmits a UE MDT_Information Report message indicated by the terminal identifier based on the acquired movement frequency information. It is determined whether to use the original radio terminal UE for MDT.

  When it is determined that the radio terminal UE is used for MDT, in step S107, the maintenance monitoring apparatus OAM transmits a transmission request for an MDT Configuration message to the radio base station eNB that has transferred the UE MDT_Information Report message. The transmission request includes the terminal identifier and the measurement configuration. The radio base station eNB receives the transmission request for the MDT Configuration message.

  In step S108, the radio base station eNB transmits an MDT Configuration message to the radio terminal UE according to the received transmission request. When receiving the MDT Configuration message, the radio terminal UE sets the measurement configuration included in the MDT Configuration message in its own terminal and starts measurement processing in MDT.

(1.5) Effects of the First Embodiment As described above, the maintenance monitoring apparatus OAM according to the first embodiment has information on the frequency with which the radio terminal UE switches the cell in which it is located, that is, information on the movement frequency of the radio terminal UE. Can be obtained from the radio terminal UE, and the radio terminal to be used for MDT is selected according to the obtained movement frequency information, so that a wide range of measurement results can be obtained, and sufficient measurement results necessary for optimization can be obtained. Can do.

(1.6) Modification 1 of the first embodiment
In 1st Embodiment mentioned above, the radio | wireless terminal UE produced | generated the movement frequency information which shows the frequency which a self-terminal switches the cell in which it exists. However, the radio terminal UE may generate movement frequency information indicating the frequency with which the own terminal switches the tracking area in which it is located. As described above, the radio terminal UE grasps the switching of the tracking area, and even if the “cell” in the first embodiment is read as the “tracking area”, the same effect as in the first embodiment can be obtained.

(1.7) Modification 2 of the first embodiment
In the first embodiment described above, the maintenance monitoring device OAM and the radio base station eNB transmit a UE MDT_Information Request message for acquiring movement frequency information to the radio terminal UE, and the radio terminal UE receives the UE MDT_Information Request message. In response to the UE MDT_Information Report message to the radio base station eNB. However, the radio terminal UE may transmit the UE MDT_Information Report message to the radio base station eNB in the process of negotiation prior to transmission of the MDT Configuration message.

  FIG. 5 is a sequence diagram showing a terminal selection method according to this modification.

  In step S201, when the maintenance monitoring apparatus OAM determines to set the measurement configuration in the radio terminal UE, the maintenance monitoring apparatus OAM transmits an MDT Configuration Negotiation message for performing negotiation with the radio terminal UE to the radio base station eNB. The radio base station eNB receives the MDT Configuration Negotiation message.

  In step S202, the radio base station eNB transmits an MDT Configuration Negotiation message to the radio terminal UE. The radio terminal UE receives the MDT Configuration Negotiation message.

  In step S203, the radio terminal UE generates movement frequency information.

  In step S204, the radio terminal UE transmits a UE MDT_Information Report message including the generated movement frequency information and a terminal identifier for identifying the own terminal to the radio base station eNB. The radio base station eNB receives the UE MDT_Information Report message. The subsequent processing is the same as in the first embodiment.

(1.8) Modification 3 of the first embodiment
Although 1st Embodiment mentioned above demonstrated the case where a network receives UE MDT_Information Report message from one radio | wireless terminal UE, you may receive UE MDT_Information Report message simultaneously from several radio | wireless terminal UE.

  FIG. 6 is a sequence diagram illustrating a terminal selection method according to this modification.

  In step S301, when the start of MDT is determined, the maintenance monitoring apparatus OAM transmits a UE MDT_Information Request message for acquiring movement frequency information to a plurality of radio base stations eNB configuring the E-UTRAN. Each of the multiple radio base stations eNB receives the UE MDT_Information Request message.

  In step S302, each of the plurality of radio base stations eNB transmits a UE MDT_Information Request message for acquiring movement frequency information to the radio terminal UE connected to the own station. Each of the plurality of radio terminals UE receives a UE MDT_Information Request message.

  In step S303, each of the plurality of radio terminals UE generates movement frequency information.

  In step S304, each of the plurality of radio terminals UE transmits a UE MDT_Information Report message including the generated movement frequency information and a terminal identifier for identifying the terminal itself to the radio base station eNB. Each of the multiple radio base stations eNB receives the UE MDT_Information Report message.

  In step S305, each of the plurality of radio base stations eNB transfers the UE MDT_Information Report message received from the radio terminal UE to the maintenance monitoring apparatus OAM. The maintenance monitoring device OAM receives the UE MDT_Information Report message.

  In step S306, the maintenance monitoring apparatus OAM acquires the movement frequency information and the terminal identifier included in each of the received UE MDT_Information Report messages, and the UE MDT_Information Report message indicated by the terminal identifier based on the acquired movement frequency information. It is determined whether or not to use the wireless terminal UE of the transmission source for MDT. Here, in addition to the method described in the first embodiment, the radio terminal UE to be used for MDT may be determined by relative comparison of a plurality of radio terminals UE. Specifically, the maintenance monitoring apparatus OAM determines to use, for MDT, a plurality of radio terminals UE having a predetermined number (for example, the highest) radio terminals with the highest movement frequency. By such a method, at least one radio terminal UE can be determined as a radio terminal UE used for MDT.

  In step S307, the maintenance monitoring apparatus OAM transmits a transmission request for the MDT Configuration message to the radio base station eNB that has transferred the UE MDT_Information Report message corresponding to the radio terminal UE used for MDT. The transmission request includes a terminal identifier of the radio terminal UE used for MDT and a measurement configuration. The radio base station eNB receives the transmission request for the MDT Configuration message.

  In step S308, the radio base station eNB transmits an MDT Configuration message to the radio terminal UE according to the received transmission request. When receiving the MDT Configuration message, the radio terminal UE sets the measurement configuration included in the MDT Configuration message in its own terminal and starts measurement processing in MDT.

(2) Second Embodiment In the terminal selection method according to the second embodiment, the location registration server (home location register HLR) transmits a message including movement frequency information or generation information, and a maintenance monitoring device The OAM (network device) receives a message including movement frequency information or generation information, and the maintenance monitoring device OAM (network device) acquires movement frequency information from the message received in the receiving step. Prepare.

  In the second embodiment, differences from the first embodiment will be mainly described. Hereinafter, the second embodiment will be described in the order of (2.1) Configuration of the maintenance monitoring apparatus, (2.2) Terminal selection method, and (2.3) Effects of the second embodiment.

(2.1) Configuration of Maintenance Monitoring Device With reference to FIG. 3 again, the configuration of the maintenance monitoring device OAM according to the second embodiment will be described with respect to differences from the first embodiment.

  When the start of MDT is determined, the movement frequency information acquisition unit 331 sends a transmission request message for acquiring movement frequency information or generation information used for generation of movement frequency information to the home location register HLR. The network communication unit 310 is controlled to transmit.

  Here, the home location register HLR can also manage the switching time of the tracking area for each radio terminal UE (for each terminal identifier). For this reason, when receiving the transmission request message, the home location register HLR transmits a response message including a list of tracking area switching times as information for generation and a terminal identifier to the maintenance monitoring device OAM. Alternatively, when the home location register HLR receives the transmission request message, the home location register HLR generates movement frequency information indicating the frequency at which the radio terminal UE switches the tracking area in the area from the list of tracking area switching times. And a response message including the terminal identifier may be transmitted to the maintenance monitoring apparatus OAM.

  After the transmission request message is transmitted, when the network communication unit 310 receives a response message including movement frequency information or generation information, the movement frequency information acquisition unit 331 includes movement frequency information or generation information included in the received response message. And the terminal identifier. When the generation information is acquired, the movement frequency information acquisition unit 331 generates and acquires movement frequency information from the generation information.

  Based on the movement frequency information acquired by the movement frequency information acquisition unit 331, the MDT use terminal determination unit 332 determines whether to use the radio terminal UE indicated by the terminal identifier for MDT. As a specific example, in the case of creating a coverage map, the MDT using terminal determining unit 332 uses the radio terminal UE for MDT when the frequency indicated by the movement frequency information is lower than a predetermined degree. If the frequency indicated by the movement frequency information is greater than or equal to a predetermined level, it is determined that the radio terminal UE is used for MDT. For example, the MDT using terminal determining unit 332 determines that a radio terminal UE having a tracking area switching frequency of less than N times per day is not used for MDT, and has a tracking area switching frequency of N times or more per day. The terminal UE is determined to be used for MDT.

  The MDT control unit 333 transmits an MDT Configuration message transmission request to the radio base station eNB to which the radio terminal UE determined to be used for MDT is connected with a measurement configuration. The transmission request includes the terminal identifier. Further, when MDT data (measurement results and position information) is reported from the radio terminal UE via the radio base station eNB, the MDT control unit 333 accumulates the reported MDT data. The accumulated MDT data is used, for example, for optimization of E-UTRAN.

(2.2) Terminal Selection Method FIG. 7 is a sequence diagram showing a terminal selection method according to the second embodiment.

  In step S401, the maintenance monitoring apparatus OAM transmits a transmission request message to the home location register HLR when the start of MDT is determined. The home location register HLR receives the transmission request message.

  In step S402, the home location register HLR transmits a response message including movement frequency information or generation information and a terminal identifier to the maintenance monitoring device OAM. The maintenance monitoring device OAM receives the response message.

  In step S403, the maintenance monitoring apparatus OAM acquires the movement frequency information or generation information and the terminal identifier included in the received response message, and indicates the terminal identifier based on the acquired movement frequency information or generation information. Whether to use the wireless terminal UE to be used for MDT.

  When it is determined that the radio terminal UE is used for MDT, in step S404, the maintenance monitoring apparatus OAM issues a transmission request for an MDT Configuration message to the radio base station eNB to which the radio terminal UE is connected, which is indicated by the terminal identifier. Send. The transmission request includes the terminal identifier and the measurement configuration. The radio base station eNB receives the transmission request for the MDT Configuration message.

  In step S405, the radio base station eNB transmits an MDT Configuration message to the radio terminal UE according to the received transmission request. When receiving the MDT Configuration message, the radio terminal UE sets the measurement configuration included in the MDT Configuration message in its own terminal and starts measurement processing in MDT.

(2.3) Effects of the Second Embodiment As described above, the maintenance monitoring device OAM according to the second embodiment is configured so that the frequency at which the radio terminal UE switches the tracking area that is in the area, that is, the frequency of movement of the radio terminal UE. Since information is acquired from the home location register HLR and the wireless terminal used for MDT is selected according to the acquired movement frequency information, a wide range of measurement results can be obtained, and the measurement results necessary for optimization can be obtained. You can get enough.

(3) Third Embodiment In the first embodiment and the second embodiment described above, the maintenance monitoring apparatus OAM selects the radio terminal UE used for MDT. In the third embodiment, radio used for MDT is used. The radio base station eNB selects the terminal UE. In the terminal selection method according to the third embodiment, the radio terminal UE transmits a message including movement frequency information, the radio base station eNB (network device) receives a message including movement frequency information, A radio base station eNB (network device) acquiring movement frequency information included in the message received in the receiving step.

  Hereinafter, for the third embodiment, (3.1) Configuration of the radio base station, (3.2) Terminal selection method, (3.3) Effects of the third embodiment, (3.4) The third embodiment Modification Example 1, (3.5) Modification Example 2 of the third embodiment, (3.6) Modification Example 3 of the third embodiment will be described in this order.

(3.1) Configuration of Radio Base Station FIG. 8 is a block diagram showing a configuration of the radio base station eNB according to the third embodiment.

  As illustrated in FIG. 8, the radio base station eNB includes an antenna 101, a radio communication unit 110, a network communication unit 120, a storage unit 130, and a control unit 140.

  The antenna 101 is used for transmission / reception of a radio signal. The wireless communication unit 110 is configured using, for example, a radio frequency (RF) circuit, a baseband (BB) circuit, and the like, and transmits and receives wireless signals via the antenna 101. The wireless communication unit 110 also modulates the transmission signal and demodulates the reception signal. The network communication unit 120 communicates with other network devices (such as the maintenance monitoring device OAM and other radio base stations eNB). The storage unit 130 is configured using, for example, a memory, and stores various types of information used for controlling the radio base station eNB. The control unit 140 is configured using, for example, a CPU, and controls various functions provided in the radio base station eNB.

  The control unit 140 includes a movement frequency information acquisition unit 141, an MDT use terminal determination unit 142, and an MDT control unit 143.

  When the start of MDT is determined, the movement frequency information acquisition unit 141 controls the radio communication unit 110 to transmit a UE MDT_Information Request message for acquiring movement frequency information to the radio terminal UE connected to the mobile station. . When the radio communication unit 110 receives the UE MDT_Information Report message after transmitting the UE MDT_Information Request message, the movement frequency information acquisition unit 141 acquires the movement frequency information and the terminal identifier included in the received UE MDT_Information Report message.

  Based on the movement frequency information acquired by the movement frequency information acquisition unit 141, the MDT use terminal determination unit 142 determines whether to use the radio terminal UE indicated by the terminal identifier for MDT. As a specific example, in the case of creating a coverage map, the MDT using terminal determining unit 142 uses the radio terminal UE for MDT when the frequency indicated by the movement frequency information is lower than a predetermined degree. If the frequency indicated by the movement frequency information is greater than or equal to a predetermined level, it is determined that the radio terminal UE is used for MDT. For example, the MDT using terminal determining unit 142 determines that a radio terminal UE whose number of cell switching per day is less than N times is not used for MDT, and the radio terminal UE whose number of cell switching per day is N or more times Is determined to be used for MDT.

  The MDT control unit 143 designates the measurement configuration and transmits an MDT Configuration message to the radio terminal UE that has been determined to be used for MDT. When the MDT data (measurement result or position information) from the radio terminal UE is reported, the MDT control unit 143 accumulates the reported MDT data. The accumulated MDT data is used, for example, for optimization of E-UTRAN.

(3.2) Terminal Selection Method FIG. 9 is a sequence diagram showing a terminal selection method according to the third embodiment.

  In step S501, when the start of MDT is determined, the radio base station eNB transmits a UE MDT_Information Request message for acquiring movement frequency information to the radio terminal UE connected to the own station. The radio terminal UE receives a UE MDT_Information Request message.

  In step S502, the radio terminal UE generates movement frequency information.

  In step S503, the radio terminal UE transmits a UE MDT_Information Report message including the generated movement frequency information and a terminal identifier for identifying the terminal itself to the radio base station eNB. The radio base station eNB receives the UE MDT_Information Report message.

  In step S504, the radio base station eNB acquires the movement frequency information and the terminal identifier included in the received UE MDT_Information Report message, and uses the radio terminal UE indicated by the terminal identifier for MDT based on the acquired movement frequency information. Decide whether or not to do.

  If it is determined that the radio terminal UE is used for MDT, in step S505, the radio base station eNB transmits an MDT Configuration message to the radio terminal UE. When receiving the MDT Configuration message, the radio terminal UE sets the measurement configuration included in the MDT Configuration message in its own terminal and starts measurement processing in MDT.

(3.3) Effects of the Third Embodiment As described above, the radio base station eNB according to the third embodiment has information on the frequency with which the radio terminal UE switches the cell in which it is located, that is, information on the movement frequency of the radio terminal UE. Can be obtained from the radio terminal UE, and the radio terminal to be used for MDT is selected according to the obtained movement frequency information, so that a wide range of measurement results can be obtained, and sufficient measurement results necessary for optimization can be obtained. Can do.

(3.4) Modification 1 of the third embodiment
In 3rd Embodiment mentioned above, the radio | wireless terminal UE produced | generated the movement frequency information which shows the frequency which a self-terminal switches the cell in which it exists. However, the radio terminal UE may generate movement frequency information indicating the frequency with which the own terminal switches the tracking area in which it is located. As described above, the radio terminal UE knows the switching of the tracking area, and even if the “cell” in the third embodiment is read as the “tracking area”, the same effect as in the third embodiment can be obtained.

(3.5) Modification 2 of the third embodiment
In the third embodiment described above, the radio base station eNB transmits a UE MDT_Information Request message for acquiring movement frequency information to the radio terminal UE, and the radio terminal UE responds to the reception of the UE MDT_Information Request message in UE. The MDT_Information Report message was transmitted to the radio base station eNB. However, the radio terminal UE may transmit the UE MDT_Information Report message to the radio base station eNB in the process of negotiation prior to transmission of the MDT Configuration message.

  FIG. 10 is a sequence diagram showing a terminal selection method according to this modification.

  In step S601, when the radio base station eNB determines to set the measurement configuration in the radio terminal UE, the radio base station eNB transmits an MDT Configuration Negotiation message for performing negotiation with the radio terminal UE to the radio terminal UE. The radio terminal UE receives the MDT Configuration Negotiation message.

  In step S602, the radio terminal UE generates movement frequency information.

  In step S603, the radio terminal UE transmits a UE MDT_Information Report message including the generated movement frequency information and a terminal identifier for identifying the own terminal to the radio base station eNB. The radio base station eNB receives the UE MDT_Information Report message. The subsequent processing is the same as in the third embodiment.

(3.6) Modification 3 of the third embodiment
In the third embodiment described above, the case where the radio base station eNB receives the UE MDT_Information Report message from one radio terminal UE has been described. However, the UE MDT_Information Report message may be received simultaneously from a plurality of radio terminals UE. .

  FIG. 11 is a sequence diagram illustrating a terminal selection method according to this modification.

  In step S701, when the start of MDT is determined, the radio base station eNB transmits a UE MDT_Information Request message for acquiring movement frequency information to a plurality of radio terminals UE connected to the own station. Each of the plurality of radio terminals UE receives a UE MDT_Information Request message.

  In step S702, each of the plurality of radio terminals UE generates movement frequency information.

  In step S703, each of the plurality of radio terminals UE transmits a UE MDT_Information Report message including the generated movement frequency information and a terminal identifier for identifying the own terminal to the radio base station eNB. The radio base station eNB receives the UE MDT_Information Report message.

  In step S704, the radio base station eNB acquires the movement frequency information and the terminal identifier included in each of the received UE MDT_Information Report messages, and based on the acquired movement frequency information, the radio base station eNB changes the radio terminal UE indicated by the terminal identifier to MDT. Decide whether or not to use. Here, in addition to the method described in the third embodiment, the radio terminal UE to be used for MDT may be determined by relative comparison of a plurality of radio terminals UE. Specifically, the radio base station eNB determines to use, for MDT, the radio terminal UE having a predetermined number (for example, the highest) of the moving frequencies among the plurality of radio terminals UE. By such a method, at least one radio terminal UE can be determined as a radio terminal UE used for MDT.

  In step S705, the radio base station eNB transmits an MDT Configuration message to the radio terminal UE used for MDT. When receiving the MDT Configuration message, the radio terminal UE sets the measurement configuration included in the MDT Configuration message in its own terminal and starts measurement processing in MDT.

(4) Other Embodiments As described above, the present invention has been described according to each embodiment. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, each embodiment and each modification described above may be implemented separately or in combination with each other. Further, in each of the above-described embodiments and each modification example, an example using MDT dedicated messages (UE MDT_Information Request message, UE MDT_Information Report message) has been described, but these messages may be incorporated in other messages. .

  In the first embodiment and the third embodiment described above, the radio terminal UE generates movement frequency information, and a UE MDT_Information Report message including the generated movement frequency information is transmitted from the radio terminal UE to the network. However, the radio terminal UE may transmit a UE MDT_Information Report message including generation information used for generation of movement frequency information to the network. The generation information is, for example, a list of cell switching times or a list of tracking area switching times of the radio terminal UE. In this case, the maintenance monitoring device OAM that has received the UE MDT_Information Report message acquires (generates) the movement frequency information from the generation information included in the UE MDT_Information Report message.

  In each embodiment and each modification described above, the number of cell switching per day or the number of tracking area switching per day is exemplified as the movement frequency information. However, more detailed information may be used. Specifically, morning hours (eg 5: 00-11: 00), noon hours (eg 11: 00-13: 00), evening hours (eg 13: 00-18: 00), It is subdivided into night time zones (for example, 18: 00-23: 00) and late-night time zones (for example, 23: 00-5: 00), and the number of cell switching or tracking area switching in a specific time zone A high radio terminal UE may be used for MDT. For example, since there is a radio base station eNB that performs energy saving in the late-night time zone, it is possible to respond to a request for intensive optimization in the late-night time zone.

  In addition, about each embodiment mentioned above, the cell switching frequency per day is good also as the average value in several days, totaling the cell switching frequency per day over several days.

  Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters in the scope of claims reasonable from this disclosure.

  HLR: Home location register, MME: Mobility management device, OAM: Maintenance monitoring device, S-GW ... Gateway device, eNB ... Wireless base station, 1 ... Mobile communication system, 101 ... Antenna, 110 ... Wireless communication unit, 120 ... Network communication unit, 130 ... Storage unit, 140 ... Control unit, 141 ... Movement frequency information acquisition unit, 142 ... MDT use terminal determination unit, 143 ... MDT control unit, 201 ... Antenna, 210 ... Wireless communication unit, 220 ... User Interface unit 230 ... GPS receiver 240 ... battery 250 ... storage unit 260 ... control unit 261 ... movement state management unit 262 ... information generation unit 263 ... MDT processing unit 310 ... network communication unit 320 ... Storage unit, 330 ... control unit, 331 ... movement frequency information acquisition unit, 332 ... MDT use terminal determination unit, 333 MDT control unit

Claims (8)

In a mobile communication system in which a tracking area is configured by one or a plurality of cells, a terminal selection method for selecting a radio terminal used for MDT,
A step of acquiring movement frequency information indicating a frequency at which a wireless terminal switches a cell or a tracking area in which the network device is located;
A step of determining whether or not to use the wireless terminal for MDT based on the movement frequency information acquired in the acquiring step; The wireless terminal or the location registration server transmitting a message including the movement frequency information;
The network device further comprising receiving the message;
The terminal selection method according to claim 1, wherein in the acquiring step, the movement frequency information included in the message received in the receiving step is acquired. The wireless terminal or the location registration server transmitting a message including information for generation used to generate the movement frequency information;
The network device further comprising receiving the message;
The terminal selection method according to claim 1, wherein in the obtaining step, the movement frequency information is obtained from the generation information included in the message received in the receiving step.   The terminal according to any one of claims 1 to 3, wherein, in the determining step, when the frequency indicated by the movement frequency information is lower than a predetermined degree, the wireless terminal is determined not to be used for MDT. Selection method. In the obtaining step, the movement frequency information for each time zone is obtained,
The terminal selection method according to any one of claims 1 to 4, wherein, in the determining step, whether to use the wireless terminal for MDT is determined based on the movement frequency information for each time period.   The network device according to claim 1, further comprising: transmitting information for setting a measurement configuration of MDT to the wireless terminal when the network device determines to use the wireless terminal for MDT in the determining step. The terminal selection method according to any one of the above. In a mobile communication system in which a tracking area is configured by one or a plurality of cells, a network device capable of selecting a radio terminal used for MDT,
An acquisition unit for acquiring movement frequency information indicating a frequency at which a wireless terminal switches a cell or a tracking area in which it is located;
A network apparatus comprising: a determination unit that determines whether to use the wireless terminal for MDT based on the movement frequency information acquired by the acquisition unit. In a mobile communication system in which a tracking area is configured by one or a plurality of cells, a wireless terminal that can be used for MDT,
A wireless terminal comprising: a transmission unit that transmits to a wireless base station a message including movement frequency information indicating a frequency of switching a cell or a tracking area where the cell is located, or generation information used for generating the movement frequency information.

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