# Patent

## Title
Measurement method, apparatus, and system for minimization of drive tests

## Abstract

The present application discloses a method, an apparatus, and a system for minimization of drive tests (MDT), and relates to the field of communications technologies. In a technical solution, by obtaining a mapping relationship between a trace control entity (TCE) address and a TCE identifier, and according to the TCE identifier included in the MDT report reported by the UE, a corresponding TCE address is obtained and the MDT report is sent to a TCE corresponding to the TCE address. Therefore, it is unnecessary to send an actual TCE network address to the user equipment. The technical solution improves security and solves the insecurity problem of the MDT measurement. The technical solution is simple, convenient and easy to implement, and reduces the complexity of network signaling interaction and network processing.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 13/937,832, filed on Jul. 9, 2013, which a continuation of International Application No. PCT/CN2012/070116, filed on Jan. 6, 2012. The International Application claims priority to Chinese Patent Application No. 201110004039.7, filed on Jan. 10, 2011. The afore-mentioned patent applications are hereby incorporated by reference in their entireties.


TECHNICAL FIELD
The present invention relates to the field of communications technologies, and in particular, to a technology of minimization of drive tests.
BACKGROUND
A network operator needs to invest a lot of manpower or money to conduct drive tests in the traditional network operation and maintenance. Moreover, a traditional drive test terminal may not reach indoors under some conditions. It is also difficult to record the traditional drive tests in some sudden network conditions. The minimization of drive tests (MDT) aims to reduce the work in the traditional drive tests conducted by an operator in building and subsequently maintaining the network, and to introduce a new user equipment (UE) function to tackle the problem that the traditional drive tests fail to solve. The UE is required by the MDT to record a network condition and a location at some time of the UE in a connected state and an idle state, and to report them to the network at the right time, thereby replacing part of the work in traditional drive tests.
The current MDT falls into two categories: immediate MDT and logged MDT. The immediate MDT is an MDT manner that a network performs MDT configurations on a UE according to the radio resource control (RRC), and the UE performs measurement in a connected state and reports a result immediately. The logged MDT is an MDT manner that a network side performs MDT configurations on the UE, and the UE transfers into an idle state to perform MDT measurement and log, and performs MDT log reporting after transferring into a connected state.
In the current Third Generation Partnership Project (3GPP) standard, the present trace function has been expanded to implement MDT measurement. A network management system configures relevant parameters of the MDT in a trace command, and sends them to an evolved NodeB (eNB) or a radio network controller (RNC). The foregoing relevant parameters of the MDT include a trace reference and a Trace control entity (TCE) IP address. After performing MDT measurement, the UE reports an MDT report to the eNB or the RNC, and the eNB or the RNC sends the MDT report to the TCE according to the TCE IP address to complete the drive tests. If the UE performs measurement in an idle state, the trace reference and the TCE IP address need to be configured for the UE by the network side through an air interface, so that when reporting the MDT report, the UE may carry the TCE IP address, thereby allowing the eNB or the RNC to find the corresponding TCE. In another technology, the eNB or the RNC configures the trace reference only for the UE. After the UE reports the trace report and the MDT report, the eNB or the RNC locally searches for the IP address of the corresponding TCE according to the trace reference. If the eNB or RNC fails to search for the IP address, it may ask a network manager (NM) entity for the TCE IP address.
However, direct configuration of the trace reference and the TCE IP address to the UE may cause safety issues because safety hazards may lurk in the operator's network once an illegal UE intercepts the TCE IP address, identifies the location of the TCE, and attacks the TCE of the operator directly. However, if the trace reference is only configured for the UE, the eNB or the RNC may not be able to determine which NM is the one that the eNB or the RNC should ask for the TCE IP address, thereby increasing the complexity of signaling interaction of the network and network processing.
SUMMARY
To solve the problem in the prior art, an aspect of the present invention provides a measurement method for minimization of drive tests. The method includes: receiving, by an access network equipment, a minimization of drive tests (MDT) report sent by a user equipment (UE), where the MDT report includes a trace control entity (TCE) identifier; obtaining, by the access network equipment, a TCE address corresponding to the TCE identifier according to a mapping relationship between the TCE address and the TCE identifier or a mapping algorithm between the TCE address and the TCE identifier; and sending, by the access network equipment, the MDT report to a TCE corresponding to the TCE address.
In another aspect, the present invention provides a MDT measurement apparatus. The apparatus includes: a receiving unit, configured to receive a MDT report sent by a UE, where the MDT report includes a TCE identifier; an obtaining unit, configured to obtain a TCE address corresponding to the TCE identifier according to a mapping relationship between the TCE address and the TCE identifier or a mapping algorithm between the TCE address and the TCE identifier; and a sending unit, configured to send the MDT report to a TCE corresponding to the TCE address.
In still another aspect, the present invention further provides a MDT measurement system, including the MDT measurement apparatus.
In still another aspect, the present invention further provides a MDT measurement method, including: reporting, by a UE, a MDT report to an access network equipment, where the MDT report includes a TCE identifier, and the TCE identifier is used by the access network equipment to obtain a TCE address corresponding to the TCE identifier according to a mapping relationship between the TCE address and the TCE identifier or a mapping algorithm between the TCE address and the TCE identifier and send the MDT report to a TCE corresponding to the TCE address.
In still another aspect, the present invention further provides a UE, including: a reporting unit, configured to report a MDT report to an access network equipment, where the MDT report includes a TCE identifier, and the TCE identifier is used by the access network equipment to obtain a TCE address corresponding to the TCE identifier according to a mapping relationship between the TCE address and the TCE identifier or a mapping algorithm between the TCE address and the TCE identifier and send the MDT report to a TCE corresponding to the TCE address.
In the technical solutions, by obtaining a mapping relationship between a TCE address and a TCE identifier, and according to a TCE identifier included in the MDT report reported by the UE, a corresponding TCE address is obtained and the MDT report is sent to a TCE corresponding to the TCE address to complete the measurement. During the measurement, it is unnecessary to send an actual network address of the TCE to the UE, which improves security and solves the insecurity problem of the MDT measurement in the prior art when a TCE IP address is sent to the UE. The technical solutions are simple, convenient, and easy to implement, and reduce the complexity of network signaling interaction and network processing.



BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a flow chart of a MDT measurement method according to Embodiment 1 of the present invention;
FIG. 2 is a flow chart of a MDT measurement method according to Embodiment 2 of the present invention;
FIG. 3 is a schematic flow chart of MDT measurement according to Embodiment 2 of the present invention;
FIG. 4 is a structural diagram of a MDT measurement apparatus according to Embodiment 3 of the present invention; and
FIG. 5 is a simplified structural diagram of a UE device according to the present invention.



DESCRIPTION OF EMBODIMENTS
To make the objectives, technical solutions, and advantages of the present invention more comprehensible, the following further describes the embodiments of the present invention in details with reference to the accompanying drawings.
Embodiment 1
Referring to FIG. 1, this embodiment provides a measurement method for minimization of drive tests, including the following contents.
101: An access network equipment receives an MDT report reported by a UE, where the MDT report includes a TCE identifier.
102: The access network equipment obtains a TCE address corresponding to the TCE identifier according to a mapping relationship between the TCE address and the TCE identifier or a mapping algorithm between the TCE address and the TCE identifier.
103: The access network equipment sends the MDT report to a TCE corresponding to the TCE address.
In the embodiment of the present invention, the access network equipment includes a base station or a base station control equipment, and for example, may include an eNB or a RNC in a long term evolution (LTE) system.
Optionally, before the access network equipment receives the MDT report reported by the UE, the access network equipment may send the TCE identifier to the UE. The access network equipment may also first obtain the mapping relationship between the TCE address and the TCE identifier, or the mapping algorithm between the TCE address and the TCE identifier.
Optionally, the method for the access network equipment to obtain the mapping relationship between the TCE address and the TCE identifier may includes: obtaining the mapping relationship between the TCE address and the TCE identifier from an attribute named TCE address information list of the base station or a cell; or obtaining the mapping relationship between the TCE address and the TCE identifier from an attribute named TCE address mapping information list of a subnetwork.
Optionally, obtaining, by the access network equipment, the mapping relationship between the TCE address and the TCE identifier, or the mapping algorithm between the TCE address and the TCE identifier, includes: receiving, by the access network equipment, the mapping relationship between the TCE address and the TCE identifier or the mapping algorithm between the TCE address and the TCE identifier that is sent by an element manager (EM) or reading, by the access network equipment, the mapping relationship between the TCE address and the TCE identifier or the mapping algorithm between the TCE address and the TCE identifier that is locally stored.
Optionally, the mapping relationship between the TCE address and TCE identifier, or the mapping algorithm between the TCE address and the TCE identifier, is obtained by the EM from an network manager (NM) through an interface northbound (Itf-N).
In the method provided by the embodiment, by obtaining a mapping relationship between a TCE address and a TCE identifier or a mapping algorithm between the TCE address and the TCE identifier, and according to the TCE identifier included in the MDT report reported by the UE, a corresponding TCE address is obtained and the MDT report is sent to a TCE corresponding to the TCE address. During the MDT measurement, it is unnecessary to send an actual network address of the TCE to the UE, which improves security and solves the insecurity problem of the MDT measurement in the prior art when a TCE IP address is sent to the UE. The method is simple, convenient, and easy to implement, and reduces the complexity of network signaling interaction and network processing.
Embodiment 2
Referring to FIG. 2, this embodiment provides a measurement method for minimization of drive tests, including the following contents.
201: An access network equipment obtains a mapping relationship between a TCE address and a TCE identifier or a mapping algorithm between a TCE address and a TCE identifier.
For the TCE address in this embodiment, a TCE IP address is briefly introduced as an example. In this embodiment, each TCE identifier may only identify a TCE. Specifically, the TCE address may be allotted a fixed number. For example, if there are 100 TCEs in a network, each of the IP addresses of the 100 TCEs is allotted a unique fixed number correspondingly, to establish a mapping relationship between the TCE IP addresses and the numbers.
Specifically, obtaining a mapping relationship between a TCE address and a TCE identifier in the step above may be achieved in any one of the following two implementation manners:
a) obtain a mapping relationship between the TCE address and the TCE identifier from an attribute named TCE address information list of a base station or a cell; or
b) obtain a mapping relationship between the TCE address and TCE identifier from an attribute named TCE address mapping information list of a subnetwork.
202: The access network equipment sends a TCE identifier corresponding to the TCE address to a UE.
203: When the UE performs MDT measurement, the access network equipment receives an MDT report reported by the UE, where the MDT report includes the TCE identifier.
204: The access network equipment obtains a TCE address corresponding to the TCE identifier according to the mapping relationship or the mapping algorithm.
205: The access network equipment sends the MDT report to a TCE corresponding to the TCE address.
Optionally, in this embodiment, the mapping relationship between the TCE address and the TCE identifier or the mapping algorithm between the TCE address and TCE identifier that is obtained by the access network equipment includes any one of the following:
a) the access network equipment receives the mapping relationship between the TCE address and the TCE identifier or the mapping algorithm between the TCE address and the TCE identifier that is sent by an EM; and
b) the access network equipment reads the mapping relationship between the TCE address and the TCE identifier or the mapping algorithm between the TCE address and the TCE identifier that is locally stored.
The mapping relationship or the mapping algorithm above is obtained by the EM from a network manager NM through a interface northbound Itf-N of a network management. For example, the NM configures the mapping relationship for the EM through the Itf-N interface and for the eNB or the RNC through the EM. The eNB or the RNC configures a TCE identifier corresponding to a TCE IP address for the UE. The UE carries the TCE identifier when reporting the MDT report. The eNB or the RNC finds a corresponding actual TCE IP address according to the TCE identifier and transmits the MDT report to the TCE according to the actual TCE IP address.
In a 3GPP network management system, an Itf-N is an interface between the network and the network management system, specifically, maybe an interface between an NM and an EM. An Itf-B is an interface between a base station and its management unit, and an Itf-R is an interface between a RNC and its management unit. For example, refer to FIG. 3, which shows that the Itf-N serves as the interface between the NM and the EM. The NM configures a mapping relationship or a mapping algorithm between a TCE IP address and a TCE identifier through the Itf-N. (1) indicates that the EM uniformly configures a mapping relationship or a mapping algorithm between a TCE IP address and a TCE identifier, and the TCE IP address, for eNB/RNC1 and eNB/RNC2. (2) indicates that the eNB/RNC only configures the TCE identifier that has been mapped or a result that has been computed according to the mapping algorithm for the UE. (3) indicates that the UE feeds back the TCE identifier and the computation result to the eNB/RNC when reporting the MDT report. (4) indicates that the eNB/RNC converts the TCE identifier into the actual TCE IP address according to the mapping relationship or converts the computation result into the actual TCE IP address according to the mapping algorithm, and sends the corresponding MDT report to a TCE corresponding to the TCE IP address.
For another example, when through an EM delivering a command by the Itf-N interface, the EM obtains a mapping relationship or a mapping algorithm between a TCE identifier and a TCE address that is specified by a operator, the EM may configure the mapping relationship or the mapping algorithm for the eNB/cell/RNC corresponding to the MDT. The eNB/cell/RNC may also obtain the mapping relationship or mapping algorithm by sending an inquiry request to the EM. Alternatively, the mapping relationship or the mapping algorithm is stored fixedly in the eNB/cell/RNC. When the MDT activates a task, the eNB/cell/RNC delivers the TCE identifier or mapped computation result to a Logged MDT UE rather than directly delivering the TCE IP address. When receiving data reported by the MDT, the eNB/cell/RNC obtains the TCE identifier or mapped computation result from the reported data, thereby obtaining which TCE address (for example, an IP address) the data needs to be forwarded, and ensuring that MDT data is reported to the corresponding TCE when it is time for the eNB/cell/RNC to report the data. A network side and UE only send the TCE identifier or the mapped computation result rather than the actual TCE IP address, thereby ensuring the security of MDT measurement.
The following examples are provided to describe the process of the newly-added attribute definition of a mapping relationship between a TCE address and a TCE identifier in attributes of an eNB, a cell, or a subnetwork.
1. Attributes of eNB
Configuration parameters based on a base station function (ENBFunction) are added to the existing 3GPP TS 32.762. For example, as an optional embodiment, an attribute named TCE IP address information list (TCEIpAddressInfoList) may be added to the attributes (Attributes) in the section related to the base station function (ENBFunction). See Table 1:










TABLE 1






Support
Read
Write


Attribute name
Qualifier
Qualifier
Qualifier







. . .
. . .
. . .
. . .


TCE IP address information list
CM
M
M


(TCEIpAddressInfoList)









Wherein, TCE IP address information list (TCEIpAddressInfoList) is a newly-added attribute named TCE IP address information list, which is both readable and writable (M stands for mandatory). Under certain conditions, the attribute is mandatory (CM). The certain conditions may be defined in attribute constraints (Attribute constraints). See Table 2:








TABLE 2





Name
Definition







. . .
. . .


Attribute Constrains of
MDT function is supported


TCE IP address information list
(The condition is


(TCEIpAddressInfoList
“MDT function is supported”).


Support Qualifier)









It is stipulated that the field TCE IP address information list is applicable only under the condition “The MDT function is supported”.
Additionally, as another optional embodiment, the attribute named TCE IP address information list (TCEIpAddressInfoList) may also be defined in the section concerning the attributes definitions and legal values in the 3GPP TS 32.762. See Table 3:









TABLE 3







Legal


Attribute Name
Definition
Values
















TCE IP address list information
This attribute contains


(TCEIpAddressInfoList)
a mapping relationship



between a TCE IP address



and a TCE identifier.









The attribute TCE IP address information list (TCEIpAddressInfoList), is used to define a mapping relationship between a TCE IP address and a TCE identifier. This parameter may serve as a configuration parameter for the eNB/RNC by a network management system. During the configuration, the attribute TCEIpAddressInfoList is delivered to the EM from the NM, to allow the operator to specify a mapping relationship between a TCE IP address and a TCE identifier to a relevant network element. At the same time, it is stipulated that the field is applicable only under the condition that the MDT function is supported.
2. Attributes of Cell
A mapping relationship between a TCE IP address and a unique TCE identifier that is delivered through the Itf-N interface may also be set on a cell object. For example, in the section concerning a cell EUtranGenericCell in the existing 3GPP TS 32.762 standard, an attribute TCE IP address information list (TCEIpAddressInfoList) is added to the attributes of the cell. See Table 4:










TABLE 4






Support
Read
Write


Attribute Name
Qualifier
Qualifier
Qualifier







. . .
. . .
. . .
. . .


TCE IP address information list
CM
M
M


(TCEIpaddressInfoList)









The mapping relationship between the TCE IP address and the unique TCE identifier is set in the field TCEIPAddressInfoList. After receiving a configuration command, the EM may obtain the mapping relationship between the TCE address and the TCE identifier that is specified by the operator.
3. Attributes of Subnetwork
A mapping relationship between a TCE IP address and a unique TCE identifier that is delivered through the Itf-N interface may also be set on a subnetwork object. For example, in the existing 3GPP TS 32.622 standard, the configuration parameter based on the Subnetwork is added. Specifically, the attribute named TCE IP address mapping information list (TCEIpaddressMappingInfoList) may be added to the attributes of the SubNetwork. See Table 5:










TABLE 5






Support
Read
Write


Attribute Name
Qualifier
Qualifier
Qualifier







. . .
. . .
. . .
. . .


TCE IP address mapping
CM
M
M


information list


(TCEIpaddressInfoList)









The attribute TCE IP address mapping information list (TCEIpaddressMappingInfoList) defines a mapping relationship between a TCE IP address and a TCE identifier, and a base station corresponding to the mapping relationship.
Optionally, the attribute TCE IP address mapping information list may also be defined in the section concerning definition and legal values in the 3GPP TS 32.622 standard. See Table 6:









TABLE 6







Legal


Attribute Name
Definition
Values
















TCE IP address mapping
The value of this attribute


information list
shall include the mapping


(TCEIpaddressInfoList)
information of:



{eNodeB, TCE IP Address



Mapping Info List which



includes Mapping information



of TCE IP addresses and the



corresponding unique identifier}









The definition of the attribute TCE IP address mapping information list (TCEIpaddressMappingInfoList) includes: {eNodeB, TCE address information list (which defines a mapping relationship between a TCE IP address and a TCE identifier)}. For example, the specified mapping relationship is configured for or stored fixedly in a specified eNodeB by a specifying an eNodeB ID.
In this embodiment, the mapping algorithm the TCE address and the TCE identifier is the mapping algorithm between the TCE address and the TCE identifier, and according to the mapping algorithm, a unique TCE identifier may be obtained by computing the TCE address. Reversibly, the TCE address may be computed and obtained according to the TCE identifier. Therefore, an MDT report reported by the UE may be sent to a TCE corresponding to the TCE address, thereby avoiding sending the actual TCE IP address to the UE, and improving the security. The base station may process a TCE IP address according to a unique mapping algorithm.
For example, if a network has 100 TCEs, each of the 100 TCE IP addresses is plus five and modulo two. Then, the corresponding mapping algorithm is uniformly configured by an operation administration and maintenance (OAM) system for the eNB or the RNC, which configures a computation result for the UE. When reporting the MDT report, the UE carries the result, which allows the eNB or the RNC to compute the TCE IP address according to the mapping algorithm and find the corresponding actual TCE. In the embodiment of the present invention, the mapping algorithm comes in a plurality of forms; the “plus five and modulo two” is only used as an example. Definitely, other algorithms may also be adopted. The embodiments of the present inventions set no limitation on the form.
In this embodiment, all the base stations or RNCs may be required to adopt the same mapping relationship or mapping algorithm, which may be fixed, or configured and replaced regularly by the OAM.
In the method provided by this embodiment, by obtaining a mapping relationship between a TCE address and TCE identifier and according to the TCE identifier included in the MDT report reported by the UE, a corresponding TCE address is obtained, and the MDT report is sent to a TCE corresponding to the TCE address. During the measurement, it is unnecessary to send an actual network address of the TCE to the UE, which improves security and solves the insecurity problem of the MDT measurement in the prior art when a TCE IP address is sent to the UE. The method is simple, convenient, and easy to implement, and reduces the complexity of network signaling interaction and network processing.
Embodiment 3
Referring to FIG. 4, this embodiment provides a measurement apparatus for minimization of drive tests, including a receiving unit 401, an obtaining unit 402, and a sending unit 403. The receiving unit 401 is configured to receive a minimization of drive tests MDT report reported by a user equipment, where the MDT report includes a trace control entity TCE identifier; the obtaining unit 402 is configured to obtain a TCE address corresponding to the TCE identifier according to a mapping relationship between a TCE address and TCE identifier or a mapping algorithm between a TCE address and a TCE identifier; and the sending unit 403 is configured to send the MDT report to a TCE corresponding to the TCE address.
In this embodiment, the obtaining unit 402 is further configured to obtain a mapping relationship between a TCE address and a TCE identifier or a mapping algorithm between a TCE address and a TCE identifier.
Optionally, the sending unit 403 is further configured to send the TCE identifier to the user equipment.
Optionally, the obtaining unit 402 may include a first obtaining subunit or a second obtaining subunit, where the first obtaining subunit is configured to obtain the mapping relationship between the TCE address and the TCE identifier in an attribute named TCE IP address information list of a base station or a cell, and the second obtaining subunit is configured to obtain the mapping relationship between the TCE address and the TCE identifier in an attribute named TCE IP address mapping information list of a sub-network.
Optionally, the obtaining unit 402 may further include: a third obtaining subunit or a fourth obtaining subunit, where the third obtaining subunit is configured to receive the mapping relationship between the TCE address and the TCE identifier or the mapping algorithm between the TCE address and the TCE identifier that is sent by an element manager EM, and the fourth obtaining subunit is configured to read the mapping relationship between the TCE address and the TCE identifier or the mapping algorithm between the TCE address and the TCE identifier that is stored by the apparatus.
The mapping relationship or the mapping algorithm involved in the third obtaining subunit is obtained from a network manager NM through an interface northbound Itf-N.
In this embodiment, the measurement apparatus for minimization of drive tests may specifically be an access network equipment of a network side, including a base station or base station control equipment, and such as an eNB or a RNC in an LTE system. The method in any of the method embodiments may be implemented on this apparatus. The details of the specific implementation process are referred to in the method embodiments, which are not repeated again herein.
The embodiment of the present invention further provides a measurement system for minimization of drive tests, including the measurement apparatus for minimization of drive tests in any one of the implementation manners in the embodiments above.
In the apparatus and system provided by the embodiment of the present invention, by obtaining a mapping relationship between a TCE address and TCE identifier and according to the TCE identifier included in the MDT report reported by the UE, a corresponding TCE address is obtained, the MDT report is sent to a TCE corresponding to the TCE address. During the measurement, it is unnecessary to send an actual network address of the TCE to the UE, which improves security and solves the insecurity problem of the MDT measurement in the prior art when a TCE IP address is sent to the UE. The apparatus and system are simple, convenient, and easy to implement, and reduce the complexity of network signaling interaction and network processing.
It should be finally noted that, persons of ordinary skill in the art should understand that all or part of the processes of the methods in the embodiments may be implemented by a computer program instructing relevant hardware. The program may be stored in a computer readable storage medium. When the program is running, the processes of the methods in the embodiments are performed. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), and the like.
Functional units in the embodiments of the present invention may be integrated into a processing module, or each of units may exist alone physically, or two or more units are integrated into a module. The integrated modules may be implemented in a form of hardware or in a form of software functional modules. If the integrated modules are implemented in the form of software functional modules and sold or used as an independent product, the integrated modules may also be stored in a computer readable storage medium. The storage medium may be a read-only memory, a magnetic disk, an optical disk, and the like. The above apparatuses and systems may perform the methods described in the corresponding method embodiments.
The descriptions are merely exemplary embodiments of the present invention, but are not intended to limit the present invention. Any modification, equivalent replacement, or improvement derived within the spirit and principle of the present invention shall fall within the protection scope of the present invention.

## Claims

1. A measurement method for minimization of drive tests (MDT) in an operation administration and maintenance (OAM) system, wherein the OAM system includes a network manager and an element manager in communication with the network manager via an interface northbound (Itf-N), the method comprising:
receiving, by the element manager a notification of a mapping between an identifier of a trace control entity (TCE) and an address of the TCE from the network manager; and
transmitting, by the element manager, information of the mapping between the identifier of the TCE and the address of the TCE to an access network device,
wherein the mapping is used by the access network device in determining the address of the TCE when the access network device receives from a user equipment device (UE) an MDT report including the identifier of the TCE and MDT data.

2. The method according to claim 1, further comprising:
establishing, by the network manager, the mapping between the identifier of the TCE and the address of the TCE.

3. The method according to claim 1, further comprising:
configuring, by the network manager, the identifier of the TCE.

4. The method according to claim 1, further comprising:
configuring, by the element manager, the address of the TCE.

5. The method according to claim 1, wherein the notification further comprises the identifier of the access network device.

6. An operation administration and maintenance (OAM) system comprise a network manager and an element manager in communication with the network manager via an interface northbound (Itf-N), wherein the element manager is configured to:
receive from the network manager via an interface northbound (Itf-N), a notification of a mapping between an identifier of a trace control entity (TCE) and an address of the TCE; and
transmit to an access network device, information of the mapping, wherein the mapping is used by the access network device in determining the address of the TCE when the access network device receives from a user equipment device (UE) an MDT report including the identifier of the TCE and MDT data.

7. The system according to claim 6, wherein the mapping is established by the network manager.

8. The system according to claim 6, wherein the identifier of the TCE is configured by the network manager.

9. The system according to claim 6, wherein the element manager is further configured to configure the address of the TCE.

10. The system according to claim 6, wherein the notification further comprises the identifier of the access network device.

11. An operation administration and maintenance (OAM) system, comprising:
a network manager; and
an element manager in communication with the network manager via an interface northbound (Itf-N),
wherein
the network manager is configured to notify the element manager of a mapping between an identifier of a trace control entity (TCE) and an address of the TCE; and
the element manager is configured to transmit information of the mapping between the identifier of the TCE and the address of the TCE to an access network device,
and wherein the mapping is used by the access network device in determining the address of the TCE when the access network device receives from a user equipment device (UE) a minimization of drive tests (MDT) report which includes the identifier of the TCE and MDT data.

12. The OAM system according to claim 11, wherein the network manager is further configured to establish the mapping between the identifier of the TCE and the address of the TCE.

13. The OAM system according to claim 11, wherein the network manager is further configured to configure the identifier of the TCE.

14. The OAM system according to claim 11, wherein the element manager is further configured to configure the address of the TCE.

15. The OAM system according to claim 11, wherein the notification further comprises the identifier of the access network device.