KR20150121376A - Method of effective logged MDT for MBMS and apparatuses thereof - Google Patents

Abstract

The present invention relates to a method and apparatus for minimization of drive test (MDT), which instructs terminals within a cell to perform cell quality measurement and report the results. A method in which a terminal measures and stores reception quality of MBMS signals, according to the present invention, comprises the following steps: receiving configuration information to measure the reception quality of the MBMS signals; measuring the reception quality of the MBMS signals based on the configuration information; storing the measured reception quality of the MBMS signals; and measuring the reception quality of the MBMS signals for a predetermined period of time and storing the same, based on the configuration information or predetermined measuring condition information when the reception of the MBMS signals is ended.

Description

[0001] METHOD AND APPARATUS FOR EFFICIENT MBMS NETWORKED MDT [

The present invention relates to a Minimization of Drive Test (MDT) method and apparatus for performing cell quality measurements on terminals in a cell and reporting the results.

A method for measuring and storing a reception quality of an MBMS signal, the method comprising: receiving configuration information for measuring a reception quality of the MBMS signal; measuring a reception quality of the MBMS signal based on the configuration information; And storing the reception quality of the MBMS signal when the reception of the MBMS signal is terminated; measuring a reception quality of the MBMS signal for a predetermined time based on the configuration information or preset measurement condition information; The method comprising the steps of:

1 is a diagram showing an example of a Logged MDT procedure.
FIG. 2 is a flowchart illustrating operations of a terminal and a network according to an exemplary embodiment of the present invention.
3 is a flowchart illustrating terminal and network operations according to another embodiment of the present invention.
4 is a flowchart illustrating terminal and network operations according to another embodiment of the present invention.
5 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.
6 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference numerals even though they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data and the like. A wireless communication system includes a user equipment (UE) and a base station (BS, or eNB). The user terminal in this specification is a comprehensive concept of a terminal in wireless communication. It is a comprehensive concept which means a mobile station (MS), a user terminal (UT), an SS (User Equipment) (Subscriber Station), a wireless device, and the like.

A base station or a cell generally refers to a station that communicates with a user terminal and includes a Node-B, an evolved Node-B (eNB), a sector, a Site, a BTS A base transceiver system, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), and a small cell.

That is, in the present specification, a base station or a cell has a comprehensive meaning indicating a part or function covered by BSC (Base Station Controller) in CDMA, Node-B in WCDMA, eNB in LTE or sector (site) And covers various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, RRH, RU, and small cell communication range.

Since the various cells listed above exist in the base station controlling each cell, the base station can be interpreted into two meanings. i) a device itself providing a megacell, a macrocell, a microcell, a picocell, a femtocell, or a small cell in relation to a wireless region, or ii) the wireless region itself. i indicate to the base station all devices that are controlled by the same entity or that interact to configure the wireless region as a collaboration. An eNB, an RRH, an antenna, an RU, an LPN, a point, a transmission / reception point, a transmission point, a reception point, and the like are exemplary embodiments of a base station according to a configuration method of a radio area. ii) may indicate to the base station the wireless region itself that is to receive or transmit signals from the perspective of the user terminal or from a neighboring base station.

Therefore, a base station is collectively referred to as a megacell, a macrocell, a microcell, a picocell, a femtocell, a small cell, an RRH, an antenna, an RU, a low power node (LPN), a point, an eNB, Quot;

Herein, the user terminal and the base station are used in a broad sense as the two transmitting and receiving subjects used to implement the technical or technical idea described in this specification, and are not limited by a specific term or word. The user terminal and the base station are used in a broad sense as two (uplink or downlink) transmitting and receiving subjects used to implement the technology or technical idea described in the present invention, and are not limited by a specific term or word. Here, an uplink (UL, or uplink) means a method of transmitting / receiving data to / from a base station by a user terminal, and a downlink (DL or downlink) .

There are no restrictions on multiple access schemes applied to wireless communication systems. Various multiple access schemes such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, Can be used. An embodiment of the present invention can be applied to asynchronous wireless communication that evolves into LTE and LTE-Advanced via GSM, WCDMA, and HSPA, and synchronous wireless communication that evolves into CDMA, CDMA-2000, and UMB. The present invention should not be construed as limited to or limited to a specific wireless communication field and should be construed as including all technical fields to which the idea of the present invention can be applied.

A TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, or an FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies can be used.

In systems such as LTE and LTE-Advanced, the uplink and downlink are configured on the basis of one carrier or carrier pair to form a standard. The uplink and the downlink are divided into a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator CHannel (PCFICH), a Physical Hybrid ARQ Indicator CHannel, a Physical Uplink Control CHannel (PUCCH), an Enhanced Physical Downlink Control Channel (EPDCCH) Transmits control information through the same control channel, and is configured with data channels such as PDSCH (Physical Downlink Shared CHannel) and PUSCH (Physical Uplink Shared CHannel), and transmits data.

On the other hand, control information can also be transmitted using EPDCCH (enhanced PDCCH or extended PDCCH).

In this specification, a cell refers to a component carrier having a coverage of a signal transmitted from a transmission point or a transmission point or a transmission / reception point of a signal transmitted from a transmission / reception point, and the transmission / reception point itself .

The wireless communication system to which the embodiments are applied may be a coordinated multi-point transmission / reception system (CoMP system) or a coordinated multi-point transmission / reception system in which two or more transmission / reception points cooperatively transmit signals. antenna transmission system, or a cooperative multi-cell communication system. A CoMP system may include at least two multipoint transmit and receive points and terminals.

The multi-point transmission / reception point includes a base station or a macro cell (hereinafter referred to as 'eNB'), and at least one mobile station having a high transmission power or a low transmission power in a macro cell area, Lt; / RTI >

Hereinafter, a downlink refers to a communication or communication path from a multipoint transmission / reception point to a terminal, and an uplink refers to a communication or communication path from a terminal to a multiple transmission / reception point. In the downlink, a transmitter may be a part of a multipoint transmission / reception point, and a receiver may be a part of a terminal. In the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted / received through a channel such as PUCCH, PUSCH, PDCCH, EPDCCH, and PDSCH is expressed as 'PUCCH, PUSCH, PDCCH, EPDCCH and PDSCH are transmitted and received'.

In the following description, an indication that a PDCCH is transmitted or received or a signal is transmitted or received via a PDCCH may be used to mean transmitting or receiving an EPDCCH or transmitting or receiving a signal through an EPDCCH.

That is, the physical downlink control channel described below may mean a PDCCH, an EPDCCH, or a PDCCH and an EPDCCH.

Also, for convenience of description, EPDCCH, which is an embodiment of the present invention, may be applied to the portion described with PDCCH, and EPDCCH may be applied to the portion described with EPDCCH according to an embodiment of the present invention.

Meanwhile, the High Layer Signaling described below includes RRC signaling for transmitting RRC information including RRC parameters.

The eNB performs downlink transmission to the UEs. The eNB includes a physical downlink shared channel (PDSCH) as a main physical channel for unicast transmission, downlink control information such as scheduling required for reception of a PDSCH, A physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission in a Physical Uplink Shared Channel (PUSCH). Hereinafter, the transmission / reception of a signal through each channel will be described in a form in which the corresponding channel is transmitted / received.

Minimization of Drive Test (MDT)

In order to optimize the cell coverage, MDT has to collect the cell quality measurement results by using the car, and to perform the cell quality measurement and report the result to the terminals in the cell. Efforts can be greatly reduced.

MDT is largely divided into logged MDT and immediate MDT. Logged MDT is a method to measure the cell quality, store the result in a log and transmit it to the network at a certain point. Immediate MDT performs cell quality measurement and transmits the result to the network Method.

 Logged The MDT is used in idle state where the terminal can not report directly to the network.

1 is a diagram showing an example of a Logged MDT procedure.

Referring to FIG. 1, a UE receives a logged MDT related configuration from a network. If the terminal has previously received the logged MDT setting, discard the log created by the existing logged MDT setting and the existing setting, and apply the new logged MDT setting. And activates a valid timer applying the logging time value. When the timer expires, the terminal discards the setting and maintains the created log for a predetermined time (e.g., 48 hours), and has the opportunity to report the log to the network during this period.

Logged The MDT configuration (Logged Measurement Configuration) may include the following information.

- Logging duration: The time to perform logging from the moment the setting is received

- Logging interval: The time to perform the next logging after logging

- Area configuration: Area that performs logging operation,

- Absolute Time Info.: Base time information for tracking the time of logging (time at which the configuration is transmitted)

If the terminal transits to the IDLE state, the terminal performs the logging operation according to the setting of the logged MDT while the validity timer is in operation. For example, according to the MDT setting, the quality measurement results (RSRP, RSRQ, RSCP, Ec / No) of the serving cell and the neighboring cell are logged together with the cell ID at a predetermined time interval (logging cycle) in a specific area. At this time, the location information value of the terminal may be included together.

When the terminal performing the logging operation in the IDLE state makes an RRC connection, it informs the network that there is a log created. The network will retrieve the log by requesting the corresponding terminal.

The network collects log information from a plurality of terminals, obtains cell quality information of the entire network, and can utilize it for network operation and optimization based on accumulated information such as finding a problem in a specific area.

In Release 12, MBMS MDT is being standardized to measure and report MBMS quality for MBMS cell coverage optimization.

MBMS MDT Related Agreements

1. The UE reports MBSFN RSRP / RSRQ per MBSFN area.

2. The UE reports MCH BLER per MCS, per MCH, and per MBSFN area.

The UE receiving the MBMS broadcast can perform the measurement operation according to the setting information received from the base station and report it to the base station. In the case where the reception quality of the MBMS service is lower than the predetermined signal quality or reception fails and users can not watch the broadcast when the corresponding broadcast is not available, Will not occur. Therefore, it is not easy for the base station to grasp the area where the MBMS reception is problematic.

The present invention enables the quality measurement and logging operation to be performed for a predetermined time even in an area where the MBMS reception is problematic so that the network receiving the corresponding result value can grasp the area where the MBMS reception is problematic.

In the present invention, a UE performing an MBMS recorded MDT performs an MBMS quality measurement and a logging operation for a predetermined time when a specific condition is satisfied. After a predetermined time, it is determined whether to continue the quality measurement according to whether the MBMS recorded MDT setting is valid or not.

FIG. 2 is a flowchart illustrating operations of a terminal and a network according to an exemplary embodiment of the present invention.

Referring to Fig. 2, each step will be described.

One. The terminal receives MBMS logged MDT related settings from the network. The setup message may be an existing logged measurement configuration message or a newly defined message in an RRC message. The MBMS logged MDT-related setting may comprise the following information.

- Logging duration: The period of time to perform logging. Start from the moment you receive the settings.

- Logging interval: The interval at which logging should be performed after logging (the interval between logging and logging)

- Area configuration: the area performing the logging operation, e.g. cell ID, MBSFN area ID, etc.

- Absolute Time: The base time information that can track the time of logging.

- Connected mode: Connected mode.

- Conditional logging duration: The period during which logging is performed from condition satisfaction

- Conditional logging interval: The interval between logging and logging used when the condition is satisfied.

- Thresholds: Reference values (RSRP / RSRQ threshold, BLER threshold,

2. The UE which has started receiving the MBMS broadcast performs MBMS quality measurement and logging according to the configuration.

3. If the following conditions are satisfied, the UE performs MBMS quality measurement and logging for a predetermined period of time.

- When the measured MBMS quality value (RSRP / RSRQ) is equal to or greater than a specific value (Threshold)

- If the measured MBMS BLER (Block Error Rate) value is less than (or equal to) a certain threshold value

- When the MBMS reception is terminated (e.g., user selection)

- When the UE transits to RRC Connected mode

- When the terminal detects RLF

 The thresholds used in the above conditions may be provided via MBMS logged MDT-related settings, or may be values defined in the spec.

The interval, duration, etc. of the MBMS quality measurement and logging performed when the condition is satisfied may be the same values as before, and other values may be applied. This is set in the previously received MBMS logged MDT configuration.

4. After completing the MBMS quality measurement and logging for a period of time, the terminal validates its MBMS logged MDT related settings.

If the information is valid and the MBMS is currently being received, the MBMS quality measurement and logging operation is continued.

Embodiment 1) When MBMS reception ends

When the MBMS receiving end of the MBMS receiving MDT is completed, if the following condition is satisfied, the MBMS quality measuring and logging operation is continued for a predetermined time and then the operation is terminated. Or terminates the logging operation when escaping from the condition before the predetermined time elapses.

- If the MBMS reception ends when the MBMS quality (RSRP / RSRQ) value is below a specific value

- When the reception of the MBMS is completed when the MBMS BLER (Block Error Rate) value is equal to or more than a specific value

3 is a flowchart illustrating terminal and network operations according to another embodiment of the present invention.

Referring to Fig. 3, each step will be described.

One. The terminal receives MBMS logged MDT related settings from the network. The setup message may be an existing logged measurement configuration message or a newly defined message in an RRC message. The MBMS logged MDT-related setting may comprise the following information.

- Logging duration: The period of time to perform logging. Start from the moment you receive the settings.

- Logging interval: The interval at which logging should be performed after logging (the interval between logging and logging)

- Area configuration: The area that performs the logging operation

- Absolute Time: The base time information that can track the time of logging.

- Connected mode: Connected mode.

- Conditional logging duration: The period during which logging is performed from condition satisfaction

- Conditional logging interval: The interval between logging and logging used when the condition is satisfied.

- Thresholds: Reference values (RSRP / RSRQ threshold, BLER threshold,

2. The UE which has started receiving the MBMS broadcast performs MBMS quality measurement and logging according to the configuration.

3. When the reception of the MBMS broadcast ends, the MBMS quality measurement value measured last is compared with the threshold value previously received through the configuration. The threshold may be a predefined value.

3-1. (MBMS signal quality value comparison) If the measured MBMS signal quality is below (or above) the threshold value, the MBMS quality measurement and logging operation is continued for a predetermined time and then ends.

3-2. (MBMS BLER value comparison) If the measured MBMS BLER value is equal to or greater than the threshold value (or below), the MBMS quality measurement and logging operation is continued for a predetermined time and then the operation ends.

The predetermined time for which the quality measurement is to be continued may be a value defined in the Spec. Or a value transmitted through the configuration.

Alternatively, instead of setting a certain time, it can be continued only when the condition is satisfied. That is, if the measured result deviates from the corresponding condition, the quality measurement and logging operation can be terminated.

Example 2) Quality measurement and logging at the time of termination

When the UE performing the MBMS recorded MDT ends the MBMS reception, the MBMS quality measurement and logging operation is performed at the end time and the operation is terminated. In addition, the quality measurement result at the end point can be compared with the following conditions, and logging can be performed only when the conditions are satisfied.

- When the reception of the MBMS is completed when the MBMS quality (RSRP / RSRQ) value is equal to or lower than a specific value

- When the MBMS reception is ended at a value equal to or higher than a specific value of the MBMS BLER (Block Error Rate) value

4 is a flowchart illustrating terminal and network operations according to another embodiment of the present invention.

Each step will be described with reference to Fig.

One. The terminal receives MBMS logged MDT related settings from the network. The setup message may be an existing logged measurement configuration message or a newly defined message in an RRC message. The MBMS logged MDT-related setting may comprise the following information.

- Logging duration: The period of time to perform logging. Start from the moment you receive the settings.

- Logging interval: The interval at which logging should be performed after logging (the interval between logging and logging)

- Area configuration: The area that performs the logging operation

- Absolute Time: The base time information that can track the time of logging.

- Connected mode: Connected mode.

- Thresholds: Reference values (RSRP / RSRQ threshold, BLER threshold,

2. The UE which has started receiving the MBMS broadcast performs MBMS quality measurement and logging according to the configuration.

3. When the reception of the MBMS broadcast ends, the UE performs the MBMS quality measurement and logging operation regardless of the logging period, and then ends.

Or the MBMS broadcast is terminated, the UE performs MBMS quality measurement and compares the result with a threshold value to determine whether to perform logging. The threshold may be received through a previous configuration or may be a predefined value.

For example, (MBMS signal quality value comparison) If the measured MBMS signal quality is below (or above) the threshold value, the quality measurement result value is logged and then terminated.

Or (MBMS BLER value comparison) If the measured MBMS BLER value is equal to or greater than the threshold value (or below), the quality measurement result value is logged and then terminated.

The present invention enables quality measurement and logging operations to be performed for a predetermined time even in a region where there is a problem in receiving MBMS, so that the network receiving the corresponding result value can grasp the region having a problem in receiving the MBMS, So that it can be managed well.

5 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.

5, a base station 1000 according to another embodiment includes a control unit 1010, a transmission unit 1020, and a reception unit 1030.

The control unit 1010 may perform a quality measurement and a logging operation for a predetermined time even in an area where the MBMS reception is necessary to perform the above-described present invention, So that the overall operation of the base station can be controlled.

The transmitting unit 1020 and the receiving unit 1030 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention to and from the terminal.

6 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.

6, a user terminal 1100 according to another embodiment includes a receiving unit 1110, a control unit 1120, and a transmitting unit 1130.

The receiving unit 1110 receives downlink control information, data, and messages from the base station through the corresponding channel.

Also, the controller 1120 may perform a quality measurement and a logging operation for a predetermined period of time in an area where the MBMS reception is necessary to perform the above-described present invention, And controls the overall operation of the terminal in order to properly grasp the area.

The transmitter 1130 transmits uplink control information, data, and a message to the base station through the corresponding channel.

The standard content or standard documents referred to in the above-mentioned embodiments constitute a part of this specification, for the sake of simplicity of description of the specification. Therefore, it is to be understood that the content of the above standard content and portions of the standard documents are added to or contained in the scope of the present invention.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (1)

A method for measuring and storing a reception quality of a Multimedia Broadcast Multicast Services (MBMS) signal,
Receiving configuration information for measuring reception quality of the MBMS signal;
Measuring reception quality of the MBMS signal based on the configuration information;
Storing the reception quality of the measured MBMS signal; And
And measuring and storing the reception quality of the MBMS signal for a predetermined time based on the configuration information or preset measurement condition information when the reception of the MBMS signal is terminated.

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