KR102254716B1 - Mobile terminal for cell reselection in cellular mobile communication system and methods therefor - Google Patents

Abstract

The present invention relates to a mobile terminal for cell reselection in a cellular mobile communication system and a method of operation thereof. The method for cell reselection of a mobile terminal includes: Performing a first cell measurement; Performing second cell measurement on one or more cells not included in the neighboring cell list based on the first cell measurement; Determining one or more candidate cells satisfying a cell reselection criterion from one or more cells of the neighboring cell list and one or more cells detected by the second cell measurement; It may include performing cell reselection to one of the one or more candidate cells. Various embodiments are possible.

Description

A mobile terminal for cell reselection in a cellular mobile communication system and its operation method {MOBILE TERMINAL FOR CELL RESELECTION IN CELLULAR MOBILE COMMUNICATION SYSTEM AND METHODS THEREFOR}

The present invention relates to cell reselection of a mobile terminal in a cellular mobile communication system, and for cell reselection when cells in a neighbor cell list are not searched in an idle state. It relates to a mobile terminal and a method of operating the same.

In a cellular mobile communication system, a mobile terminal enters an idle state, checks whether paging is received every paging period, and performs cell measurement on cells included in a neighbor cell list. can do. For example, when measuring the cell, reception powers of neighboring cells for determining cell reselection criteria may be measured. Here, the list of neighboring cells may be included in a system information block (SIB) and broadcast in each cell.

When cells satisfying a cell reselection criterion are searched for for a predetermined time from a cell measurement result based on the neighboring cell list, reselection may be performed with the corresponding cell.

However, when the list of neighboring cells obtained from broadcast system information is incorrectly configured, the mobile terminal may not be able to find a neighboring cell for cell reselection even though the channel quality of the serving cell is deteriorating. At this time, if a neighboring cell for cell reselection is not found for a certain period of time, the mobile terminal determines that it is out of service and proceeds with a cell selection procedure. However, there may be a problem in that paging reception for receiving a service is limited during a waiting time for determining the out of service state and a time for performing cell selection.

1 illustrates a scenario in which a neighboring cell for cell reselection is not found in a cellular mobile communication system according to various embodiments.

Referring to FIG. 1, when configuring a network, a list of neighboring cells may be configured in consideration of a path that a mobile terminal moves to a path of a base station A → a base station B → a base station C → a base station D. For example, base station A broadcasts a list of neighboring cells including base stations B and C, base station B broadcasts a list of neighboring cells including base stations A and C, and base station C broadcasts a list of neighboring cells including base stations B and D, Base station D may broadcast a list of neighboring cells including base stations A and C.

However, when the mobile terminal moves to the path of base station A → base station B → base station D, since the mobile terminal does not include base station D in the list of neighboring cells of base station B, the mobile terminal has a list of neighboring cells of base station B. Cell measurement may be performed for base stations A and C included in. Accordingly, the mobile terminal may not perform reselection of the base station D, and may perform a cell selection procedure after a predetermined time.

Therefore, in order to improve the problem that the mobile terminal misses paging when cells included in the neighboring cell list set by the network are not found nearby and the quality of the serving cell deteriorates, a method and apparatus for cell reselection are provided. need.

Various embodiments of the present invention can provide a mobile terminal for cell reselection in a cellular mobile communication system and a method of operating the same.

Various embodiments of the present invention can provide a method and apparatus for performing cell reselection by searching for a cell that is not in the neighboring cell list when a cell in the neighboring cell list is not found in the vicinity of the mobile terminal.

According to various embodiments of the present disclosure, there is provided a method for cell reselection of a mobile terminal, the method comprising: performing a first cell measurement on one or more cells of a serving cell and a neighboring cell list; Performing second cell measurement on one or more cells not included in the neighboring cell list based on the first cell measurement; Determining one or more candidate cells satisfying a cell reselection criterion from one or more cells of the neighboring cell list and one or more cells detected by the second cell measurement; It may include performing cell reselection to one of the one or more candidate cells.

According to various embodiments of the present disclosure, in a mobile terminal for cell reselection, a first cell measurement is performed on one or more cells of a serving cell and a neighboring cell list, and based on the first cell measurement. Thus, a measurement module for performing second cell measurement on one or more cells not included in the neighboring cell list; A determination module for determining one or more candidate cells satisfying a cell reselection criterion from one or more cells of the neighboring cell list and one or more cells detected by the second cell measurement; And a cell reselection control module that performs cell reselection to one of the one or more candidate cells.

According to various embodiments of the present disclosure, at least one processor; Memory; And one or more programs stored in the memory and configured to be executed by the one or more processors, wherein the program is stored in at least one cell not included in a neighbor cell list according to at least one condition. Determine whether to perform measurement, and if at least one condition is satisfied, measurement is performed on at least one cell not included in the neighboring cell list, and at least one cell not included in the neighboring cell list A command for selecting a cell that satisfies the cell reselection criterion may be included.

As described above, when a cell in the neighboring cell list is not found near the mobile terminal, the frequency of entering an out of service state by searching for a cell that is not in the neighboring cell list and performing cell reselection. It is possible to reduce the paging reception performance by reducing the out of service (out of service) state can be improved.

In addition, paging reception performance may be improved by reducing the frequency of Inter-RAT/inter-frequency cell reselection.

In addition, it is possible to reduce the frequency of cell reselection and reduce the current through cell reselection to cells of good quality.

1 illustrates a scenario in which a neighboring cell for cell reselection is not found in a cellular mobile communication system according to various embodiments.
2 is a diagram illustrating a network environment including an electronic device according to various embodiments of the present disclosure.
3 is a block diagram of a cell reselection module of the electronic device of FIG. 2 according to various embodiments of the present disclosure.
4 illustrates a discontinuous reception (DRX) cycle according to various embodiments.
5 is a flowchart illustrating a network entry procedure of a mobile terminal according to various embodiments of the present disclosure.
6 is a flowchart for cell reselection of a mobile terminal in a cellular mobile communication system according to various embodiments of the present disclosure.
7 is a flowchart illustrating a cell search procedure for cells in a detection cell list according to various embodiments of the present disclosure.
8 is a flowchart for a cell search procedure for cells in a neighbor cell list according to various embodiments of the present disclosure.
9 is a block diagram of an electronic device according to various embodiments of the present disclosure.

Hereinafter, various embodiments of the present invention will be described in connection with the accompanying drawings. Various embodiments of the present invention may be modified in various ways and may have various embodiments, and specific embodiments are illustrated in the drawings and related detailed descriptions are described. However, this is not intended to limit the various embodiments of the present invention to specific embodiments, it should be understood to include all changes and/or equivalents or substitutes included in the spirit and scope of the various embodiments of the present invention. In connection with the description of the drawings, similar reference numerals have been used for similar elements.

Expressions such as "include" or "may include" that may be used in various embodiments of the present invention indicate the existence of a corresponding function, operation, or component that has been disclosed, and an additional one or more functions, operations, or It does not limit the components, etc. In addition, in various embodiments of the present invention, terms such as "comprises" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, It is to be understood that it does not preclude the possibility of the presence or addition of one or more other features or numbers, steps, actions, components, parts, or combinations thereof.

In various embodiments of the present invention, expressions such as "or" include any and all combinations of words listed together. For example, "A or B" may include A, may include B, or may include both A and B.

Expressions such as “first,” “second,” “first,” or “second,” used in various embodiments of the present invention may modify various elements of various embodiments, but limit the corresponding elements. I never do that. For example, the expressions do not limit the order and/or importance of corresponding elements. The above expressions may be used to distinguish one component from another component. For example, a first user device and a second user device are both user devices and represent different user devices. For example, without departing from the scope of the rights of various embodiments of the present invention, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component.

When a component is referred to as being "connected" or "connected" to another component, the component is directly connected to or may be connected to the other component, but the component and It should be understood that new other components may exist between the other components. On the other hand, when a component is referred to as being "directly connected" or "directly connected" to another component, it will be understood that no new other component exists between the component and the other component. Should be able to.

The terms used in various embodiments of the present invention are only used to describe specific embodiments, and are not intended to limit the various embodiments of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

Unless otherwise defined, all terms including technical or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which various embodiments of the present invention belong. Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless explicitly defined in various embodiments of the present invention, ideal or excessively formal It is not interpreted in meaning.

An electronic device according to various embodiments of the present disclosure may be a device including a communication function. For example, electronic devices include smartphones, tablet PCs, mobile phones, video phones, e-book readers, desktop personal computers, and laptops. Laptop personal computer (PC), netbook computer, personal digital assistant (PDA), portable multimedia player (PMP), MP3 player, mobile medical device, camera, or wearable device (e.g.: It may include at least one of a head-mounted-device (HMD) such as electronic glasses, an electronic clothing, an electronic bracelet, an electronic necklace, an electronic appcessory, an electronic tattoo, or a smart watch.

According to some embodiments, the electronic device may be a smart home appliance having a communication function. Smart home appliances, for example, include televisions, digital video disk (DVD) players, audio, refrigerators, air conditioners, vacuum cleaners, ovens, microwave ovens, washing machines, air purifiers, set-top boxes, and TVs. It may include at least one of a box (eg, Samsung HomeSync™, Apple TV™, or Google TV™), game consoles, electronic dictionary, electronic key, camcorder, or electronic frame.

According to some embodiments, the electronic device is a variety of medical devices (e.g., magnetic resonance angiography (MRA), magnetic resonance imaging (MRI), computed tomography (CT)), an imager, an ultrasonic device, etc.), a navigation device, and a GPS receiver. (global positioning system receiver), EDR (event data recorder), FDR (flight data recorder), automobile infotainment device, marine electronic equipment (e.g. marine navigation equipment and gyro compass, etc.), avionics, It may include at least one of a security device, a vehicle head unit, an industrial or domestic robot, an automatic teller's machine (ATM) of a financial institution, or a point of sales (POS) of a store.

According to some embodiments, the electronic device is a piece of furniture or building/structure including a communication function, an electronic board, an electronic signature receiving device, a projector, or various types of devices. It may include at least one of measurement devices (eg, water, electricity, gas, or radio wave measurement devices). An electronic device according to various embodiments of the present disclosure may be a combination of one or more of the aforementioned various devices. Also, an electronic device according to various embodiments of the present disclosure may be a flexible device. In addition, it is apparent to those skilled in the art that the electronic device according to various embodiments of the present disclosure is not limited to the above-described devices.

Hereinafter, an electronic device according to various embodiments will be described with reference to the accompanying drawings. The term user used in various embodiments may refer to a person using an electronic device or a device (eg, an artificial intelligence electronic device) using an electronic device.

Hereinafter, various embodiments of the present invention will be described with respect to an electronic device for cell reselection in a cellular mobile communication system and a method of operating the same.

In particular, various embodiments of the present invention provide a cell measurement for searching for cells not included in a neighbor cell list provided from a network when the electronic device is in a standby state of a cellular mobile communication system (hereinafter, a detection cell (Referred to as detected cell measurement), (2) managing the detection cell, and (3) performing reselection to the detection cell.

2 is a diagram illustrating a network environment 200 including an electronic device 201 according to various embodiments of the present disclosure. Referring to FIG. 2, the electronic device 201 may include a bus 210, a processor 220, a memory 230, an input/output interface 240, a display 250, a communication interface 260, and a cell reselection module 270.

The bus 210 may be a circuit that connects the above-described components to each other and transmits communication (eg, a control message) between the above-described components.

The processor 220 includes, for example, the other components described above through the bus 210 (eg, the memory 230, the input/output interface 240, the display 250, the communication interface 260, or the cell reselection module 270, etc.) It is possible to receive an instruction from, decrypt the received instruction, and perform an operation or data processing according to the decrypted instruction.

The memory 230 may be received from the processor 220 or other components (eg, the input/output interface 240, the display 250, the communication interface 260, the cell reselection module 270, etc.) or the processor 220 or other components Can store commands or data generated by The memory 230 may include programming modules such as a kernel 231, middleware 232, an application programming interface (API) 233, or an application 234, for example. Each of the above-described programming modules may be composed of software, firmware, hardware, or a combination of at least two or more of them.

The kernel 231 includes system resources (e.g., the bus 210, the processor 220) used to execute the operation or function implemented in the other programming modules, for example, the middleware 232, the API 233, or the application 234. Alternatively, the memory 230, etc.) may be controlled or managed. In addition, the kernel 231 may provide an interface through which the middleware 232, the API 233, or the application 234 can access and control or manage individual components of the electronic device 201.

The middleware 232 may serve as an intermediary so that the API 233 or the application 234 communicates with the kernel 231 to exchange data. In addition, the middleware 232 in relation to the job requests received from the application 234, for example, to at least one of the applications 234 system resources of the electronic device 201 (for example, the bus 210, the processor 220, or Control (eg, scheduling or load balancing) on a work request may be performed by using a method such as assigning a priority that can use the memory 230 or the like.

The API 233 is an interface for the application 234 to control functions provided by the kernel 231 or the middleware 232, for example, at least one interface or function for file control, window control, image processing or text control, etc. (Example: command) can be included.

According to various embodiments, the application 234 is an SMS/MMS application, an email application, a calendar application, an alarm application, a health care application (eg, an application that measures exercise amount or blood sugar), or an environmental information application (eg: An application that provides information on atmospheric pressure, humidity, or temperature), etc. may be included. Additionally or alternatively, the application 234 may be an application related to information exchange between the electronic device 201 and an external electronic device (eg, the electronic device 204). The application related to the information exchange may include, for example, a notification relay application for delivering specific information to the external electronic device, or a device management application for managing the external electronic device. I can.

For example, the notification delivery application transmits notification information generated from another application (eg, SMS/MMS application, e-mail application, health management application, environment information application, etc.) of the electronic device 201 to an external electronic device (eg, electronic device 204). ) Can be included. Additionally or alternatively, the notification delivery application may receive notification information from, for example, an external electronic device (eg, electronic device 204) and provide it to a user. The device management application includes, for example, a function for at least a part of an external electronic device (eg, electronic device 204) communicating with the electronic device 201 (eg, turning on/on of the external electronic device itself (or some component parts)). Turn off or adjust the brightness (or resolution) of the display), manage applications running on the external electronic device or services (eg, call service or message service) provided by the external electronic device (eg, install, delete, or update) )can do.

According to various embodiments, the application 234 may include an application designated according to a property (eg, type of electronic device) of the external electronic device (eg, electronic device 204). For example, when the external electronic device is an MP3 player, the application 234 may include an application related to music playback. Similarly, when the external electronic device is a mobile medical device, the application 234 may include an application related to health management. According to an embodiment, the application 234 may include at least one of an application specified in the electronic device 201 or an application received from an external electronic device (eg, the server 206 or the electronic device 204).

The input/output interface 240 includes commands or data input from a user through an input/output device (eg, a sensor, a keyboard, or a touch screen), for example, the processor 220, the memory 230, and the communication interface 260 through the bus 210. Alternatively, it may be transmitted to the cell reselection module 270. For example, the input/output interface 240 may provide data on a user's touch input through a touch screen to the processor 220. In addition, the input/output interface 240 may transmit commands or data received from the processor 220, the memory 230, the communication interface 260, or the cell reselection module 270 through the bus 210, for example, to the input/output device (for example: Speaker or display). For example, the input/output interface 240 may output voice data processed through the processor 220 to a user through a speaker.

The display 250 may display various types of information (eg, multimedia data or text data) to a user.

The communication interface 260 may connect communication between the electronic device 201 and an external device (eg, the electronic device 204 or the server 206). For example, the communication interface 260 may be connected to a network 262 through wireless communication or wired communication to communicate with the external device. The wireless communication, for example, Wifi (wireless fidelity), BT (Bluetooth), NFC (near field communication), GPS (global positioning system) or cellular communication (e.g., LTE, LTE-A, CDMA, WCDMA, UMTS , WiBro or GSM, etc.). The wired communication may include, for example, at least one of a universal serial bus (USB), a high definition multimedia interface (HDMI), a recommended standard 232 (RS-232), or a plain old telephone service (POTS).

According to an embodiment, the network 262 may be a telecommunications network. The communication network may include at least one of a computer network, the Internet, the Internet of things, and a telephone network. According to an embodiment, a protocol for communication between the electronic device 201 and an external device (eg, transport layer protocol, data link layer protocol, or physical layer protocol) is an application 234, an application programming interface 233, the middleware 232, and a kernel 231. Alternatively, it may be supported by at least one of the communication interfaces 260.

According to an embodiment, the cell reselection module 270 processes at least some of information obtained from other components (eg, the processor 220, the memory 230, the input/output interface 240, the communication interface 260, etc.) And, it can be provided to the user in various ways. For example, the cell reselection module 270 uses the processor 220 or independently, in a standby state (1) cell measurement for searching for cells not in a neighbor cell list provided from the network ( Hereinafter, at least some functions of the electronic device 201 may be controlled to perform (referred to as detected cell measurement), (2) manage the detection cell, and (3) perform reselection to the detection cell. I can.

2 is a block diagram 200 of a cell reselection module 270 of an electronic device (eg, electronic device 201) according to various embodiments. Referring to FIG. 2, the cell reselection module 270 may include a measurement module 310, a determination module 320, and a cell selection control module 330.

The measurement module 310 may measure reception powers of cells in a neighbor cell list or a detection cell list. For example, the measurement module 310 may measure a reception power or a signal-to-interference ratio (eg, Ec/Io) of a pilot signal or a reference signal transmitted from the base station to the electronic device. The E _c /I _o denotes a ratio of the energy of a pilot signal accumulated over a period of one PN chip to the total power spectral density in the reception band, and may represent the reception sensitivity of the electronic device. The neighboring cell list is information provided to the mobile terminal through a system information block (SIB), and the detection cell list is cells detected by a cell search procedure of the mobile terminal shown in FIG. 7 below. These may be the remaining cells that do not include cells included in the neighboring cell list.

The determination module 320 may determine cell reselection based on a cell measurement result from the measurement module 310. For example, if the reception level of the serving cell is greater than a given first threshold, it continues to stay in the serving cell. Otherwise, cell reselection may be triggered to select another cell. The triggering criterion for the cell reselection may be delivered by system information (eg, system information block (SIB) #3, #4).

In addition, the determination module 320 may determine a measurement for detecting cells other than the neighboring cell list (hereinafter, referred to as a detected cell measurement). For example, the determination module 320, when the signal quality of the serving cell (e.g., E _c /I _o or RSCP (Received Signal Code Power)) falls below a second threshold (hereinafter, referred to as a first condition), the neighbor set list When at least one cell of is not detected for a predetermined time or for a predetermined number of measurements (hereinafter, the second condition), or when the serving cell is changed (hereinafter, the third condition), when at least one condition is satisfied, the The detection cell measurement can be performed.

Here, the second threshold for determining whether to measure the detection cell may be the same value or different values for the first threshold for determining the cell reselection. In addition, the second threshold value, like the first threshold value, may not be broadcasted from the base station to the electronic device as system information, or may not need to be broadcast from the base station to the electronic device at a predefined value. Preferably, the second threshold value is greater than the first threshold value and may be determined to be a value predefined in the electronic device. In addition, the second threshold may be set equally or differently for each terminal.

The cell selection control module 330 may control cell reselection based on a determination result from the determination module 320. In addition, when triggering for the cell reselection occurs, the cell selection control module 330 may select a cell that satisfies a cell reselection criterion from the neighboring cell list or the detection cell list. Parameters required for the cell reselection may be determined through system information broadcast from a corresponding cell. Alternatively, when reselection parameters for cells included in the detection cell list are not received from a corresponding cell, reselection parameters of cells included in the neighboring cell list may be used.

The cell selection control module 330 may control to preferentially perform reselection to a cell of the neighboring cell list when a cell of the neighboring cell list and a cell of the detection cell list simultaneously satisfy a cell reselection criterion.

In addition, when triggering for the detection cell measurement occurs, the cell selection control module 330 detects at least one cell through a cell search procedure of FIG. 7 and generates a list of detected cells. Can be managed.

4 illustrates a discontinuous reception (DRX) cycle according to various embodiments.

Referring to FIG. 4, the DRX cycle (or section) 401 is divided into a wake-up section 402 and a sleep section 403. In the wake-up period 402, the mobile terminal may receive a page signal 410 in a wake-up state or perform a neighbor cell measurement (hereinafter referred to as cell measurement) 420 for cell reselection. The sleep period 203 is a state in which power supply or a clock of a module of the mobile terminal that is not in use is cut off.

The paging 410 section is a section in which information indicating whether there is a call or data to be received by mobile terminals is transmitted, and the mobile terminal can check whether its own paging identifier is included from the received paging information.

The cell measurement period 420 is a period for measuring reception powers of neighboring cells for determining a cell reselection criterion. For example, the cell measurement 420 may mean measuring a reception power or a signal-to-interference ratio (eg, Ec/Io) of a pilot signal or a reference signal transmitted from a base station to a mobile terminal. The E _c /I _o denotes a ratio of the accumulated pilot signal energy during one PN chip period to the total power spectral density in the reception band, and may represent the reception sensitivity of the mobile terminal.

For example, during the cell measurement 420 section, measurement may be performed on first cells of a neighbor cell list or second cells of a detection cell list. The neighboring cell list is information provided to the mobile terminal through system information blocks #11 and #12, and the detection cell list is at least detected by the cell search procedure of the mobile terminal shown in FIG. 7 below. It can be a list of one cell.

For example, cells not included in the neighboring cell list as well as cells not included in the neighboring cell list are detected by the cell search procedure of FIG. 7 below, and measurements are performed on the detected cells concurrently. I can. In addition, cells included in neighboring cell lists may be measured by the cell search procedure of FIG. 8 below.

That is, when the neighboring cell list is received through SIB #11 and #12 and information related to scrambling search for a neighboring cell is received, the mobile terminal performs a cell search procedure of FIG. 8 for cells included in the neighboring cell list. Based on, measurements may be performed on cells included in the neighboring cell list. On the other hand, if relevant information for any cells is not received, the mobile terminal may perform cell measurement based on the cell search procedure of FIG. 7 below.

5 is a flowchart of a mobile terminal entering a network according to various embodiments of the present disclosure.

Referring to FIG. 5, when the mobile terminal is powered on in step 500, it scans RF channels to search/select an available Public Land Mobile Network (PLMN).

In step 502, the mobile terminal selects a cell with the strongest signal among cells in the selected PLMN, and camps on the cell selected in step 504. In the camped-on state, the mobile terminal may monitor related system information or perform necessary measurements (eg, cell measurement) for a cell reselection evaluation procedure. A detailed description of the camp-on state will be described in FIG. 6 below.

In step 506, the mobile terminal may determine whether cell reselection is required based on cell measurement. For example, it may be determined whether there is a cell having a better channel state than the currently camped-on cell.

When the cell reselection is not required, the mobile terminal proceeds to step 504, and when the cell reselection is required, proceeds to step 508, and can camp-on by reselecting a cell of a better channel.

6 is a flowchart for cell reselection of a mobile terminal in a cellular mobile communication system according to various embodiments of the present disclosure.

Referring to FIG. 6, the mobile terminal may enter the idle mode when there is no incoming/outgoing call or no transmission/reception data in step 600.

In step 602, the mobile terminal determines whether it is a wake-up period during the DRX cycle in FIG. 4.

If the mobile terminal is not a wake-up period during the DRX cycle, the mobile terminal may proceed to step 602 to maintain the sleep state.

In the case of the wake-up period during the DRX cycle, the mobile terminal may proceed to step 604 to perform paging reception and first cell measurement. For example, the first cell measurement may be a CIPCH Ec/Io or CIPCH RSCP measurement of a cell included in a serving cell or a neighbor cell list. The first measurement may be performed for a predetermined time or a predetermined number of times.

In step 606, the mobile terminal may determine whether to perform detected cell measurement based on the first cell measurement. That is, after detecting cells not included in the neighboring cell list through the cell search procedure of FIG. 7 below, it may be determined whether to perform measurement on the detected cells.

For example, if at least one of the following conditions is satisfied, a cell not included in the neighboring cell list may be measured (hereinafter referred to as a second cell measurement) through the cell search procedure of FIG. 7 in step 610. . On the other hand, when the following conditions are not satisfied, measurement (eg, first cell measurement) may be performed on cells included in the neighboring cell list through the cell search procedure of FIG. 8 in step 608.

Condition 1. When the quality of the serving cell (e.g., CIPCH (common pilot channel) E _c /I _o or CIPCH RSCP (Received Signal Code Power)) falls below the threshold (Q_serv)

Condition 2. A cell is not found in the neighboring cell list for a certain period of time (T_detected).

Condition 3. When the serving cell is changed

In this case, the detection cell measurement may be performed for T_initial time or N_initial number of times when any one of the above conditions is satisfied.

In various embodiments, during the cell search procedure of FIG. 7 below, not only cells of the neighboring cell list but also cells not included in the neighboring cell list may be detected.

In various embodiments, cells included in the neighboring cell list may be omitted, and the cell search procedure of FIG. 7 may be performed only for detected cells.

In step 612, when cells not included in the neighboring cell list are detected through the second cell measurement, the mobile terminal may proceed to step 614, and if not, proceed to step 620.

In step 614, the mobile terminal may add the detection cell to a corresponding list. For example, the detection cell may be added to the neighboring cell list or a separate cell list (eg, a detection cell list) may be created and managed.

In step 616, the mobile terminal may determine whether a parameter related to reselection exists for the detected cells.

When a parameter related to reselection exists for the detected cells, the mobile terminal proceeds to step 620 and when there is no parameter related to reselection, the mobile terminal may obtain a parameter related to reselection of the detected cells. For example, the mobile terminal may obtain a parameter related to cell reselection by receiving system information broadcast from the detected cell. For example, the parameter may be a parameter for determining a rank for each cell.

In various embodiments, the procedure for obtaining a parameter related to cell reselection may be reserved until a cell reselection condition is satisfied. In addition, cells included in the detection cell list may be periodically measured together with cells in the neighboring cell list until a cell reselection procedure is performed.

In various embodiments, a parameter related to the reselection of the detected cells may be replaced with a parameter used for a cell in the neighboring cell list.

In step 620, the mobile terminal may determine a ranking for cells in the neighbor cell list or the detection cell list using a parameter related to the cell reselection.

In step 622, the mobile terminal may determine whether there is a candidate cell that satisfies the cell reselection criterion.

When a candidate cell that satisfies the cell reselection criterion is found, the mobile terminal may proceed to step 624. If the candidate cell is not found, the mobile terminal may proceed to step 604.

In step 624, the mobile terminal may determine whether the candidate cell is a cell in the detection cell list. Alternatively, the mobile terminal may determine whether the candidate cell is a cell added to the neighbor cell list.

When it is determined that the candidate cell is a cell in the detection cell list, the mobile terminal may proceed to step 626, and if not, proceed to step 628.

In step 626, if condition 4 or condition 5 is simultaneously satisfied, the mobile terminal may proceed to step 630, and if any one condition is not satisfied, the mobile terminal may proceed to step 628. That is, if a cell that satisfies the cell reselection criteria is a cell in the neighboring cell list and a cell in the detection cell list, it is determined that reselection is made to a cell in the neighboring cell list first, and even if priority is applied to the cells in the neighboring cell list. When the threshold is not reached, a cell in the detection cell list can be reselected.

Condition 4: detected cell quality> Neighbor cell quality + Q_penality

* Q_penalty: This is a condition for giving priority to a cell in the neighboring cell list, and can be greater than or equal to 0.

Condition 5: Detected cell quality> Q_threshold

* When the signal quality of the detection cell is more than a predefined threshold

In various embodiments, the signal quality of a neighboring cell that satisfies the cell reselection criterion may be applied when the signal quality is less than or equal to a predefined threshold.

If condition 4 or condition 5 is not satisfied, the mobile terminal may perform cell reselection based on system information (SIB) for a neighbor cell list in step 628.

On the other hand, when conditions 4 and 5 are satisfied, the mobile terminal may perform cell reselection based on system information (SIB) for a list of detected cells in step 630.

7 is a flowchart illustrating a cell search procedure for cells in a detection cell list according to various embodiments of the present disclosure.

7, in the cell search procedure, slot synchronization is performed in step 700, frame synchronization and code-group identification are performed in step 702, and scrambling in step 704. Scrambling-code identification can be performed. In the slot synchronization step, slot synchronization may be obtained by matching a first synchronization code and a received signal using a matched filter. In the frame synchronization and code group identification step, frame synchronization may be obtained using a second synchronization code and a code group may be identified. In the scrambling code identification step, the scrambling code may be determined through symbol by symbol correlation.

Through the cell search procedure of FIG. 7, not only cells of the neighboring cell list but also cells not included in the neighboring cell list may be detected.

8 is a flowchart for a cell search procedure for cells in a neighbor cell list according to various embodiments of the present disclosure.

Referring to FIG. 8, in the cell search procedure, slot synchronization may be performed in step 700, and scrambling-code identification may be performed in step 704. In the slot synchronization step, slot synchronization may be obtained by matching a first synchronization code and a received signal using a matched filter. If information related to a scrambling code is obtained for a cell in a neighboring cell list through system information, the frame synchronization and code group identification steps may be omitted.

Accordingly, through the simple cell search procedure of FIG. 8, measurement is performed on the cells of the neighboring cell list, and cells not included in the neighboring cell list may not be detected.

9 is a block diagram 900 of an electronic device 201 according to various embodiments. The electronic device 901 may constitute, for example, all or part of the electronic device 201 shown in FIG. 2. Referring to FIG. 9, the electronic device 901 includes at least one application processor (AP) 910, a communication module 920, a subscriber identification module (SIM) card 924, a memory 930, a sensor module 940, an input device 950, a display 960, and It may include an interface 970, an audio module 980, a camera module 991, a power management module 995, a battery 996, an indicator 997, and a motor 998.

The AP 910 may control a plurality of hardware or software components connected to the AP 910 by driving an operating system or an application program, and may perform various data processing and operations including multimedia data. The AP 910 may be implemented with, for example, a system on chip (SoC). According to an embodiment, the AP 910 may further include a Graphic Processing Unit (GPU) (not shown).

The communication module 920 (for example, the communication interface 160) transmits and receives data in communication between the electronic device 901 (for example, the electronic device 201) and other electronic devices (for example, the electronic device 204 or the server 206) connected through a network. You can do it. According to an embodiment, the communication module 920 may include a cellular module 921, a Wifi module 923, a BT module 925, a GPS module 927, an NFC module 928, and a radio frequency (RF) module 929.

The cellular module 921 may provide a voice call, a video call, a text service, or an Internet service through a communication network (eg, LTE, LTE-A, CDMA, WCDMA, UMTS, WiBro, GSM, etc.). In addition, the cellular module 921 may distinguish and authenticate electronic devices within a communication network using, for example, a subscriber identification module (eg, a SIM card 924). According to an embodiment, the cellular module 921 may perform at least some of the functions that the AP 910 can provide. For example, the cellular module 921 may perform at least a part of a multimedia control function.

According to an embodiment, the cellular module 921 may include a Communication Processor (CP). In addition, the cellular module 921 may be implemented as an SoC, for example. In FIG. 8, components such as the cellular module 921 (for example, a communication processor), the memory 830, or the power management module 995 are shown as separate components from the AP 910, but according to an embodiment, the AP 910 May be implemented to include at least some of the above-described components (eg, the cellular module 921).

According to an embodiment, the AP 910 or the cellular module 921 (for example, a communication processor) loads and processes a command or data received from at least one of a nonvolatile memory or other components connected to each of the volatile memory. can do. In addition, the AP 910 or the cellular module 921 may store data received from at least one of the other components or generated by at least one of the other components in a nonvolatile memory.

Each of the Wifi module 923, the BT module 925, the GPS module 927, or the NFC module 928 may include, for example, a processor for processing data transmitted and received through a corresponding module. In FIG. 8, the cellular module 921, the Wifi module 923, the BT module 925, the GPS module 927, or the NFC module 928 are shown as separate blocks, respectively, but according to an embodiment, the cellular module 921, the Wifi module 923, the BT module 925, the GPS At least some (eg, two or more) of the module 927 or the NFC module 928 may be included in one integrated chip (IC) or IC package. For example, at least some of the processors corresponding to each of the cellular module 921, the Wifi module 923, the BT module 925, the GPS module 927, or the NFC module 928 (e.g., a communication processor corresponding to the cellular module 921 and a communication processor corresponding to the Wifi module 923 Wifi processor) can be implemented with one SoC.

The RF module 929 may transmit/receive data, for example, transmit/receive an RF signal. Although not shown, the RF module 929 may include, for example, a transceiver, a power amp module (PAM), a frequency filter, or a low noise amplifier (LNA). In addition, the RF module 929 may further include a component for transmitting and receiving an electromagnetic wave in a free space in wireless communication, for example, a conductor or a conducting wire. In FIG. 9, the cellular module 921, the Wifi module 923, the BT module 925, the GPS module 927, and the NFC module 928 are shown to share one RF module 929 with each other, but according to an embodiment, the cellular module 921 and the Wifi module 923 At least one of the BT module 925, the GPS module 927, and the NFC module 928 may transmit/receive an RF signal through a separate RF module.

The SIM card 924 may be a card including a subscriber identification module, and may be inserted into a slot formed at a specific position of the electronic device. The SIM card 924 may include unique identification information (eg, integrated circuit card identifier (ICCID)) or subscriber information (eg, international mobile subscriber identity (IMSI)).

The memory 930 (for example, the memory 230) may include an internal memory 932 or an external memory 834. The built-in memory 932 may be, for example, a volatile memory (e.g., dynamic RAM (DRAM), static RAM (SRAM), synchronous dynamic RAM (SDRAM), etc.)) or non-volatile memory (e.g., , At least one of OTPROM (one time programmable ROM), PROM (programmable ROM), EPROM (erasable and programmable ROM), EEPROM (electrically erasable and programmable ROM), mask ROM, flash ROM, NAND flash memory, NOR flash memory, etc.) It may include.

According to an embodiment, the internal memory 932 may be a solid state drive (SSD). The external memory 934 is a flash drive, for example, compact flash (CF), secure digital (SD), micro secure digital (Micro-SD), mini secure digital (mini-SD), extreme digital (xD), or a memory stick. And the like may be further included. The external memory 934 may be functionally connected to the electronic device 901 through various interfaces. According to an embodiment, the electronic device 901 may further include a storage device (or storage medium) such as a hard drive.

The sensor module 940 may measure a physical quantity or detect an operating state of the electronic device 901 to convert the measured or sensed information into an electric signal. The sensor module 940 is, for example, a gesture sensor 940A, a gyro sensor 940B, an atmospheric pressure sensor 940C, a magnetic sensor 940D, an acceleration sensor 940E, a grip sensor 940F, a proximity sensor 940G, a color sensor 940H (e.g., RGB (red, green, blue) sensor), a biometric sensor 940I, a temperature/humidity sensor 940J, an illuminance sensor 940K, or an ultra violet (UV) sensor 940M. Additionally or alternatively, the sensor module 940 may include, for example, an olfactory sensor (E-nose sensor, not shown), an EMG sensor (electromyography sensor, not shown), an EEG sensor (electroencephalogram sensor, not shown), and an ECG sensor ( An electrocardiogram sensor, not shown), an infrared (IR) sensor (not shown), an iris sensor (not shown), or a fingerprint sensor (not shown). The sensor module 940 may further include a control circuit for controlling at least one or more sensors included therein.

The input device 950 may include a touch panel 952, a (digital) pen sensor 954, a key 856, or an ultrasonic input device 958. The touch panel 952 may recognize a touch input using at least one of, for example, a capacitive type, a pressure sensitive type, an infrared type, or an ultrasonic type. In addition, the touch panel 952 may further include a control circuit. In the case of capacitive type, physical contact or proximity recognition is possible. The touch panel 952 may further include a tactile layer. In this case, the touch panel 952 may provide a tactile reaction to a user.

The (digital) pen sensor 954 may be implemented using, for example, a method identical or similar to that of receiving a user's touch input or a separate recognition sheet. The key 856 may include, for example, a physical button, an optical key, or a keypad. The ultrasonic input device 958 is a device capable of checking data by detecting sound waves with a microphone (eg, a microphone 988) in the electronic device 901 through an input tool that generates an ultrasonic signal, and is capable of wireless recognition. According to an embodiment, the electronic device 901 may receive a user input from an external device (eg, a computer or a server) connected thereto by using the communication module 920.

The display 960 (eg, the display 250) may include a panel 962, a hologram device 964, or a projector 966. The panel 962 may be, for example, a liquid-crystal display (LCD) or an active-matrix organic light-emitting diode (AM-OLED). The panel 962 may be implemented to be flexible, transparent, or wearable, for example. The panel 962 may be configured with the touch panel 952 as a single module. The hologram device 964 may show a 3D image in the air using interference of light. The projector 966 may display an image by projecting light onto a screen. The screen may be located inside or outside the electronic device 901, for example. According to an embodiment, the display 960 may further include a control circuit for controlling the panel 962, the hologram device 964, or the projector 966.

The interface 970 may include, for example, a high-definition multimedia interface (HDMI) 972, a universal serial bus (USB) 974, an optical interface 876, or a D-subminiature (D-sub) 878. The interface 970 may be included in, for example, the communication interface 260 illustrated in FIG. 2. Additionally or alternatively, the interface 970 includes, for example, a mobile high-definition link (MHL) interface, a secure digital (SD) card/multi-media card (MMC) interface, or an infrared data association (IrDA) standard interface. can do.

The audio module 980 may convert a sound and an electric signal bidirectionally. At least some components of the audio module 980 may be included in, for example, the input/output interface 240 illustrated in FIG. 2. The audio module 980 may process sound information input or output through, for example, a speaker 982, a receiver 984, an earphone 986, or a microphone 988.

The camera module 891 is a device capable of photographing still images and moving pictures, and according to an embodiment, one or more image sensors (eg, a front sensor or a rear sensor), a lens (not shown), an image signal processor (ISP), not shown. ) Or flash (not shown) (eg, LED or xenon lamp).

The power management module 995 may manage power of the electronic device 901. Although not shown, the power management module 995 may include, for example, a power management integrated circuit (PMIC), a charger integrated circuit (IC), or a battery or fuel gauge.

The PMIC may be mounted in, for example, an integrated circuit or an SoC semiconductor. Charging methods can be divided into wired and wireless. The charger IC may charge a battery and prevent overvoltage or overcurrent from flowing from a charger. According to an embodiment, the charger IC may include a charger IC for at least one of a wired charging method or a wireless charging method. The wireless charging method includes, for example, a magnetic resonance method, a magnetic induction method, or an electromagnetic wave method, and additional circuits for wireless charging, for example, a circuit such as a coil loop, a resonance circuit, or a rectifier may be added. have.

The battery gauge may measure, for example, the remaining amount of the battery 996, voltage, current, or temperature during charging. The battery 996 may store or generate electricity, and supply power to the electronic device 901 by using the stored or generated electricity. The battery 996 may include, for example, a rechargeable battery or a solar battery.

The indicator 997 may display a specific state of the electronic device 901 or a part thereof (eg, the AP 910), for example, a booting state, a message state, or a charging state. The motor 998 may convert an electrical signal into mechanical vibration. Although not shown, the electronic device 901 may include a processing device (eg, a GPU) for supporting mobile TV. The processing device for supporting mobile TV may process media data according to standards such as digital multimedia broadcasting (DMB), digital video broadcasting (DVB), or media flow.

Each of the aforementioned components of an electronic device according to various embodiments of the present disclosure may be composed of one or more components, and the name of the corresponding component may vary according to the type of the electronic device. An electronic device according to various embodiments of the present disclosure may include at least one of the above-described components, and some components may be omitted or additional other components may be further included. In addition, some of the constituent elements of an electronic device according to various embodiments of the present disclosure are combined to form a single entity, so that functions of the corresponding constituent elements before the combination may be performed in the same manner.

The term "module" used in various embodiments of the present invention may mean a unit including one or a combination of two or more of hardware, software, or firmware, for example. “Module” may be used interchangeably with terms such as unit, logic, logical block, component, or circuit. “Module” may be the smallest unit or part of an integrally configured part. A “module” may be a minimum unit or a part of one or more functions. The “module” can be implemented mechanically or electronically. For example, the "module" according to various embodiments of the present invention is known or developed in the future, an application-specific integrated circuit (ASIC) chip, field-programmable gate arrays (FPGAs), or programmable logic that performs certain operations. It may include at least one of programmable-logic devices.

According to various embodiments, at least a part of an apparatus (eg, modules or functions thereof) or a method (eg, operations) according to various embodiments of the present disclosure may be computer-readable in the form of, for example, a programming module. It can be implemented as a command stored in a computer-readable storage media. When the instruction is executed by one or more processors (eg, the processor 122), the one or more processors may perform a function corresponding to the instruction. The computer-readable storage medium may be, for example, the memory 130. At least a part of the programming module may be implemented (for example, executed) by the processor 210, for example. At least a part of the programming module may include, for example, a module, a program, a routine, a set of instructions or a process for performing one or more functions.

The computer-readable recording medium includes magnetic media such as hard disks, floppy disks, and magnetic tapes, and optical recording media such as Compact Disc Read Only Memory (CD-ROM) and Digital Versatile Disc (DVD). Media), Magnetic-Optical Media such as a floptical disk, and program commands such as read only memory (ROM), random access memory (RAM), flash memory, etc. A hardware device specially configured to store and perform modules). Further, the program instruction may include not only machine language codes such as those produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The above-described hardware device may be configured to operate as one or more software modules to perform operations of various embodiments of the present invention, and vice versa.

A module or a programming module according to various embodiments of the present disclosure may include at least one or more of the above-described components, some of the above-described components may be omitted, or additional other components may be further included. Operations performed by a module, a programming module, or other components according to various embodiments of the present disclosure may be executed sequentially, in parallel, repeatedly, or in a heuristic manner. In addition, some operations may be executed in a different order, omitted, or other operations may be added.

According to various embodiments, in a storage medium storing instructions, the instructions are set to cause the at least one processor to perform at least one operation when executed by at least one processor, and the at least one operation is , A method for cell reselection of a mobile terminal, the method comprising: performing a first cell measurement on one or more cells of a serving cell and a neighboring cell list; Performing second cell measurement on one or more cells not included in the neighboring cell list based on the first cell measurement; Determining one or more candidate cells satisfying a cell reselection criterion from one or more cells of the neighboring cell list and one or more cells detected by the second cell measurement; It may include performing cell reselection to one of the one or more candidate cells.

The second cell measurement includes at least one of a first condition in which the signal strength of the serving cell is less than or equal to a threshold, a second condition in which cells in the neighboring cell list are not searched for a predetermined time, and a third condition in which the serving cell is changed. It can be performed when the condition of is satisfied. The second cell measurement may be performed for a predetermined time or a predetermined number of times.

The method may further include generating a detection cell list based on the second cell measurement.

The method may further include acquiring system information for the cell reselection for one or more cells detected by the second cell measurement.

The method is an operation of using system information for cell reselection for a cell in the neighboring cell list when there is no system information for the cell reselection for one or more cells detected by the second cell measurement. It may further include.

In the operation of performing cell reselection with one of the one or more candidate cells, when a neighboring cell and a detection cell simultaneously satisfy a cell reselection criterion, a cell for cell reselection is given by giving priority to the neighboring cell. It may include an operation of selecting.

The operation of performing cell reselection with one of the one or more candidate cells may include selecting a cell for cell reselection according to a standard procedure when the detection cell satisfies a cell reselection criterion.

The second cell measurement may include slot synchronization; Frame synchronization and code group identification; And a cell search procedure for obtaining at least one of scrambling code identification.

The first cell measurement may include slot synchronization; And a cell search procedure for obtaining at least one of scrambling code identification.

In addition, the embodiments of the present invention disclosed in the specification and drawings are only provided to provide specific examples to easily explain the technical content of according to the embodiments of the present invention and to aid in understanding of the embodiments of the present invention, and the scope of the embodiments of the present invention I am not trying to limit it. Therefore, the scope of various embodiments of the present invention should be interpreted as being included in the scope of various embodiments of the present invention in addition to the embodiments disclosed herein, all changes or modified forms derived based on the technical idea of various embodiments of the present invention. .

401: DRX section, 402: wake-up section
403: sleep period, 410: paging reception
420: cell measurement interval

Claims (20)

In the operating method of the terminal,
A process of performing a first cell measurement related to at least one first cell included in a serving cell and a neighboring cell list, and
A process of determining whether a first condition is satisfied based on the first cell measurement, and
A process of performing second cell measurement to detect at least one second cell not included in the neighboring cell list among the scanned cells; and
Determining at least one candidate cell that satisfies a cell reselection criterion from among the at least one first cell and the at least one second cell,
Including the process of reselecting one of the at least one candidate cell,
The first condition includes at least one of whether the signal strength of the serving cell is less than or equal to a threshold value, whether the at least one first cell is not detected for a predetermined time, or whether the serving cell is changed,
The process of determining the at least one candidate cell,
If the second condition is satisfied, including the process of determining the at least one candidate cell from among the at least one second cell,
The second condition is,
A condition in which a difference between a first quality value related to the at least one first cell and a second quality value related to the at least one second cell is greater than a penalty value, and a condition wherein the first quality value is less than a threshold value. How to.
The method according to claim 1,
The second cell measurement,
A method performed for a predetermined amount of time or a predetermined number of times.
The method according to claim 1,
Detecting the at least one second cell that is not included in the neighboring cell list; and
And generating a list of detected cells based on the at least one second cell.
The method according to claim 1,
The method further comprising obtaining system information for cell reselection related to the at least one second cell.
The method of claim 4,
If there is no system information for the cell reselection related to the at least one second cell, the method further comprising the step of using the system information for the cell reselection related to the cell included in the neighboring cell list.
The method according to claim 1,
The process of determining the at least one candidate cell,
And determining the at least one candidate cell from among the at least one first cell when the second condition is not satisfied.
The method according to claim 1,
The second cell measurement,
Slot synchronization;
Frame synchronization and code group identification; And
A method that is a cell search procedure for obtaining scrambling code identification.
The method according to claim 1,
The first cell measurement,
Slot synchronization; And
A method that is a cell search procedure for obtaining scrambling code identification.
In the terminal,
Including at least one processor,
The at least one processor,
Performing a first cell measurement related to at least one first cell included in the serving cell and the neighboring cell list,
Determine whether a first condition is satisfied based on the first cell measurement,
Performing a second cell measurement to detect at least one second cell not included in the neighboring cell list among the scanned cells,
Determining at least one candidate cell that satisfies a cell reselection criterion from among the at least one first cell and the at least one second cell,
Configured to reselect one of the at least one candidate cell,
The first condition includes at least one of whether the signal strength of the serving cell is less than or equal to a threshold value, whether the at least one first cell is not detected for a predetermined time, or whether the serving cell is changed,
The at least one processor is configured to determine the at least one candidate cell from among the at least one second cell when a second condition is satisfied,
The second condition is,
A condition in which a difference between a first quality value related to the at least one first cell and a second quality value related to the at least one second cell is greater than a penalty value, and a condition that the first quality value is less than a threshold value Terminal.
The method of claim 9,
The at least one processor,
Detecting the at least one second cell not included in the neighboring cell list,
A terminal configured to generate a detection cell list based on the second cell measurement.
The method of claim 9,
The at least one processor,
A terminal configured to obtain system information for cell reselection related to the at least one second cell.
The method of claim 11,
The at least one processor,
When there is no system information for the cell reselection related to the at least one second cell, the terminal using system information for cell reselection related to a cell included in the neighboring cell list.
The method of claim 9,
The at least one processor determines the at least one candidate cell from among the at least one second cell when the second condition is satisfied in order to determine the at least one candidate cell.
The method of claim 13,
The at least one processor determines the at least one candidate cell from among the at least one first cell when the second condition is not satisfied in order to determine the at least one candidate cell.
In a system on chip (SOC), SOC is,
Performing a first cell measurement related to at least one first cell included in the serving cell and neighbor cell list,
Determine whether a first condition is satisfied based on the first cell measurement,
Performing a second cell measurement to detect at least one second cell not included in the neighboring cell list among the scanned cells,
Determining at least one candidate cell satisfying a cell reselection criterion from among the at least one first cell and the at least one second cell,
Configured to reselect one of the at least one candidate cell,
The first condition includes at least one of whether the signal strength of the serving cell is less than or equal to a threshold, whether the at least one first cell is not detected for a predetermined time, or whether the serving cell is changed,
The SOC is configured to determine the at least one candidate cell from among the at least one second cell when a second condition is satisfied,
The second condition is,
A condition in which a difference between a first quality value related to the at least one first cell and a second quality value related to the at least one second cell is greater than a penalty value, and a condition that the first quality value is less than a threshold value SOC to do.
The method of claim 15,
The SOC is,
Detecting the at least one second cell not included in the neighboring cell list,
SOC, configured to generate a detection cell list based on the second cell measurement.
The method of claim 15,
The SOC is,
SOC, configured to obtain system information for cell reselection related to the at least one second cell.
The method of claim 17,
The SOC is,
SOC using system information for cell reselection related to a cell included in the neighbor cell list when there is no system information for the cell reselection related to the at least one second cell.
The method of claim 15,
The SOC is,
SOC for determining the at least one candidate cell from among the at least one first cell when the second condition is not satisfied.


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