JP2012147170A - Radio communication terminal device and radio quality recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication terminal device and a radio quality recording method for recording cell quality of peripheral cells without omission and reducing the amount of information to be recorded.SOLUTION: A measurement part 102 measures the cell quality of a cell where a terminal 100 is located at present and the cell quality of the peripheral cells, and measurement results are stored in a cell quality storage part 105. In the case that the terminal 100 is in a standby state, a logging control part 104 makes the location cell quality and peripheral cell quality stored in the cell quality storage part 105 be selectively recorded in a log memory 109 in every logging cycle on the basis of input of a timer 108. At the time, for the cell quality of the peripheral cells, only the cell quality newly measured from the previous logging is recorded.

Description

  The present invention relates to a radio communication terminal apparatus and radio quality recording method for measuring and recording cell quality.

  In order to newly install a base station in a cellular radio system, it is necessary to investigate the location where radio waves from the base station are difficult to reach (so-called coverage holes), such as the shadow of a building, and on-site investigation of interference with neighboring cells. Etc. are essential. Even after the base station is installed, it is necessary to adjust operation parameters according to traffic conditions.

  On the other hand, information such as cell radio strength at each point, signal-to-interference ratio (hereinafter collectively referred to as “cell quality”), and neighboring relationships with neighboring cells are collected and collected by operating terminals. In recent years, an autonomous optimization network (SON: Self Optimizing Network) that autonomously optimizes operation parameters by making reports is gaining attention.

  In 3GPP (3rd Generation Partnership Project) that standardizes UMTS and LTE systems, several functions are standardized in order to realize SON. Among them, the MDT (Minimization of Drive Test) function that collects the cell quality at each location in a terminal that is waiting is currently being standardized as a method for efficiently detecting coverage holes, inter-cell interference, and the like.

  If the cell quality of the serving cell is not sufficient, the terminal may fail to receive the signal transmitted from the base station. Even if the cell quality of the serving cell is waiting in a cell with sufficient quality, the cell quality of the serving cell may deteriorate as a result of the terminal moving. For this reason, the waiting terminal measures the cell quality of its own cell (located cell) at the period of receiving the incoming signal, and if the cell quality of its own cell is below a certain level, Based on the carrier information, the cell quality of neighboring cells is measured. Further, even when the cell quality of the own cell is above a certain level, the cell quality of the neighboring cells is measured with a long cycle such as once every few minutes for some carriers. The terminal retains these cell qualities, and determines the optimum serving cell using the lowest cell quality broadcast from the serving cell (for example, parameters such as Srxlevmin and Squalmin) (Cell reselection) (for example, non-patent) Reference 1 and Non-Patent Document 2).

  The MDT, which is being standardized by 3GPP, uses a cell that has been instructed to collect cell quality, as well as location information such as time information, cell ID and GPS positioning results, as well as the serving cell used for cell reselection determination and The cell quality of peripheral cells is recorded at a certain period (logging). The collected records (logs) are transmitted based on a request from the base station when the terminal transitions to the next communication state. Moreover, in MDT, in order to suppress the memory cost of a terminal, it is assumed that an upper limit is set for the size of a log recorded by the terminal. In addition, the MDT is intended to collect cell quality on a service provider network (PLMN: Public Land Mobile Network) when receiving a cell quality collection request (for example, see Non-Patent Document 3). ).

3GPP TS 36.304 V9.4.0 (2010-10) 3GPP TS 25.304 V9.3.0 (2010-10) 3GPP TS 37.320 V1.0.0 (2010-9)

  In an environment where a lot of relatively small cells are arranged such as in an urban area, the terminal may have the cell quality of a large number of neighboring cells. If the cell quality of all the neighboring cells is recorded in the log, more detailed information can be obtained, but the amount of information to be recorded at a time increases, and as a result, the log collection period is shortened.

  An object of the present invention is to provide a radio communication terminal apparatus and a radio quality recording method that record the cell quality of neighboring cells without omission and reduce the amount of information to be recorded.

  The wireless communication terminal apparatus of the present invention includes a measuring unit that measures cell quality of a serving cell and cell quality of a neighboring cell, and a recording unit that records the measured cell quality of the serving cell and the cell quality of the neighboring cell. And the measured cell quality of the serving cell is recorded in the recording means at a fixed recording cycle, and the cell of the peripheral cell measured in the immediately preceding recording cycle out of the measured cell quality of the peripheral cell And a control unit that records only the quality on the recording unit.

  The radio quality recording method of the present invention includes a measuring step of measuring the cell quality of a serving cell and the cell quality of a neighboring cell, recording the measured cell quality of the serving cell at a constant recording period, and measuring the cell quality. And a recording step of recording only the cell quality of the peripheral cell measured in the immediately preceding recording cycle among the cell qualities of the peripheral cell.

  According to the present invention, it is possible to record the cell quality of neighboring cells without omission and to reduce the information amount of the recorded cell quality.

The block diagram which shows the structure of the radio | wireless communication terminal device which concerns on one embodiment of this invention The figure shown on a time-axis about an example of the cell quality measurement operation | movement by the terminal shown in FIG. 1, and a logging operation | movement.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(One embodiment)
FIG. 1 is a block diagram showing a configuration of a wireless communication terminal apparatus (hereinafter referred to as “terminal”) 100 according to an embodiment of the present invention. Hereinafter, the configuration of the terminal 100 will be described with reference to FIG.

  The measurement unit 102 measures the cell quality of the cell in which the terminal 100 is currently located, and measures the radio quality of the neighboring cell based on the information of the neighboring carrier broadcast by the cell. The measurement unit 102 outputs the measurement result to the cell quality storage unit 105 of the logging control unit 104.

  The transmission / reception unit 103 receives a signal transmitted from a radio communication base station apparatus (hereinafter referred to as “base station”), and makes the received signal a logging control unit 104. When broadcast information is included in the received signal, the transmission / reception unit 103 outputs the received broadcast information to the carrier-PLMN relationship storage unit 110. Further, the transmission / reception unit 103 transmits the information output from the logging control unit 104 to the base station via the antenna 101.

  The logging control unit 104 includes a cell quality storage unit 105 that stores the serving cell quality and neighboring cell quality input from the measurement unit 102, and a cell quality determination unit 106 that determines whether the cell quality exceeds a predetermined threshold. And a carrier determination unit 107 that determines whether or not each carrier broadcasted as a peripheral carrier belongs to the PLMN when the cell quality acquisition request is received.

  When the terminal 100 is in the standby state, the logging control unit 104 selectively selects the serving cell quality and the neighboring cell quality stored in the cell quality storage unit 105 for each logging period based on the input of the timer 108. It records in the log memory 109 as a recording means. Specific conditions for recording the cell quality of the neighboring cells will be described later.

  In addition, when the terminal 100 is in a communication state, the logging control unit 104 receives a cell quality recording request from the base station through the transmission / reception unit 103, and receives a log acquisition request from the base station in the communication state, The stored cell quality is transmitted to the base station through the transmission / reception unit 103.

  The carrier-PLMN relationship storage unit 110 acquires the broadcast information output from the transmission / reception unit 103 and stores the correspondence relationship between the peripheral carriers and the PLMN included in the broadcast information. The correspondence relationship between each carrier and the PLMN is, for example, reported on the SIB (System Information Block) 18 if the cell is in the UMTS system cell, and is reported from the cell in the LTE system if the cell is in the service area. It is constructed from the PLMN information of the cell to be processed.

  Next, conditions (1) to (3) for allowing the logging control unit 104 to record the cell quality of the peripheral cells in the log memory 109 will be described.

Condition (1)
When the cell quality stored in the cell quality storage unit 105 in the logging cycle is recorded in the log memory 109, only the peripheral cell quality newly output from the measurement unit 102 since the previous logging is recorded. As a result, while the peripheral cells measured by the terminal are recorded in the log without omission, the already recorded cell quality is not recorded in the log, so that the log size can be suppressed.

Condition (2)
When the cell quality stored in the cell quality storage unit 105 is recorded in the log memory 109 in the logging cycle, only the cell quality exceeding a predetermined threshold is recorded. As a result, only cells with sufficient cell quality are recorded in the log, and cells that are not sufficient in cell quality and cannot be in the serving cell are not recorded in the log, so that the log size can be suppressed. A predetermined threshold value may be acquired from the base station. In this case, the threshold value of the cell quality to be recorded can be controlled on the network side.

Condition (3)
When the cell quality stored in the cell quality storage unit 105 is recorded in the log memory 109 in the logging period, the cell quality on the carrier determined by the carrier determination unit 107 to belong to the PLMN when the cell quality recording request is received Only record. Thereby, since the cell quality on the carrier owned by the PLMN that has received the cell quality recording request is not stored, the log size can be suppressed.

  Conditions (1) to (3) may be used alone or in combination with any two conditions. Moreover, you may use combining all three conditions.

  FIG. 2 shows an example of cell quality measurement operation and logging operation by the terminal shown in FIG. 1 on the time axis. In FIG. 2, 201 indicates a serving cell quality measurement period. Hereinafter, the condition (1) will be described with reference to FIG.

  In the logging operation 211 and the logging operation 214, since the neighboring cell measurement is not performed in the immediately preceding logging cycle, the logging control unit 104 does not record the neighboring cell quality in the log memory 109. In the logging operation 213, since the cell quality on the carrier 1 is measured by the peripheral cell measurement 212 in the immediately preceding logging cycle, the logging control unit 104 sets the cell quality on the carrier 1 as the peripheral cell quality as the log memory 109. To record. As a result, while the peripheral cells measured by the terminal are recorded in the log without omission, the already recorded cell quality is not recorded in the log, so that the log size can be suppressed.

  Next, the condition (3) will be described with reference to FIG. In the logging cycle immediately before the logging operation 216, the cell quality measurement on the carrier 2 is performed by the peripheral cell measurement 215. However, since it is determined that the carrier 2 belongs to a PLMN different from the PLMN that has received the cell quality recording request, the logging control unit 104 does not record the peripheral cell quality in the log memory 109 at the time of the logging operation 216. Thereby, since the cell quality on the carrier owned by the PLMN that has received the cell quality recording request is not stored, the log size can be suppressed.

  As described above, according to the present embodiment, when logging is performed to record the cell quality of the serving cell at a certain period, only the cell quality newly measured from the previous logging is also obtained for the cell quality of the neighboring cells. By recording, it is possible to record the cell quality of the peripheral cells without omission and to reduce the information amount of the recorded cell quality.

  The radio communication terminal apparatus and radio quality recording method according to the present invention can be applied to a mobile communication system such as UMTS or LTE.

DESCRIPTION OF SYMBOLS 101 Antenna 102 Measurement part 103 Transmission / reception part 104 Logging control part 105 Cell quality storage part 106 Cell quality determination part 107 Carrier determination part 108 Timer 109 Log memory 110 Carrier-PLMN relation storage part

Claims (5)

Measuring means for measuring the cell quality of the serving cell and the cell quality of the neighboring cells;
Recording means for recording the measured cell quality of the serving cell and the cell quality of the surrounding cell;
The recorded cell quality is recorded in the recording unit at a fixed recording period, and only the cell quality of the peripheral cell measured in the immediately preceding recording period is measured out of the measured cell quality of the peripheral cell. Control means for recording the recording means;
A wireless communication terminal apparatus comprising:   The radio communication terminal apparatus according to claim 1, wherein the control unit causes the recording unit to record only cell quality of neighboring cells exceeding a predetermined threshold.   The radio communication terminal apparatus according to claim 2, wherein the predetermined threshold is notified from a radio communication base station apparatus.   The control means stores PLMN (Public Land Mobile Network) when receiving a request for recording cell quality of a neighboring cell from a radio communication base station apparatus, and stores the stored cell quality of the neighboring cell among the measured cell quality of the neighboring cell The radio communication terminal apparatus according to claim 1, wherein the recording unit records only the cell quality of a neighboring cell on a carrier determined to belong to a PLMN. A measurement process for measuring the cell quality of the serving cell and the cell quality of the neighboring cells;
Record the measured cell quality of the in-zone cell at a fixed recording period, and record only the cell quality of the neighboring cell measured in the immediately preceding recording period among the measured cell quality of the neighboring cell. Recording process;
A wireless quality recording method comprising:

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