WO2024073965A1

WO2024073965A1 - Cell selection or reselection in energy saving network

Info

Publication number: WO2024073965A1
Application number: PCT/CN2023/071044
Authority: WO
Inventors: Ran YUE; Lianhai WU; Jing HAN; Jie Hu
Original assignee: Lenovo (Beijing) Ltd.
Priority date: 2023-01-06
Filing date: 2023-01-06
Publication date: 2024-04-11

Abstract

Methods and apparatuses for cell selection or reselection in an energy saving network are disclosed. In one embodiment, a UE comprises a processor; and a transceiver coupled to the processor, wherein, the UE supports network energy saving (NES), and the processor is configured to search a cell to be selected or reselected; and determine the cell to be selected or reselected in consideration of system information of the cell.

Description

CELL SELECTION OR RESELECTION IN ENERGY SAVING NETWORK

FIELD

The subject matter disclosed herein generally relates to wireless communications, and more particularly relates to methods and apparatuses for cell selection or reselection in an energy saving network.

BACKGROUND

The following abbreviations are herewith defined, at least some of which are referred to within the following description: New Radio (NR) , Very Large Scale Integration (VLSI) , Random Access Memory (RAM) , Read-Only Memory (ROM) , Erasable Programmable Read-Only Memory (EPROM or Flash Memory) , Compact Disc Read-Only Memory (CD-ROM) , Local Area Network (LAN) , Wide Area Network (WAN) , User Equipment (UE) , Evolved Node B (eNB) , Next Generation Node B (gNB) , Uplink (UL) , Downlink (DL) , Central Processing Unit (CPU) , Graphics Processing Unit (GPU) , Field Programmable Gate Array (FPGA) , Orthogonal Frequency Division Multiplexing (OFDM) , Radio Resource Control (RRC) , User Entity/Equipment (Mobile Terminal) , Transmitter (TX) , Receiver (RX) , master information block (MIB) , synchronization signal block (SSB) , system information block (SIB) , unified access control (UAC) , access category (AC) , access identity (AI) , network energy saving (NES) , random access channel (RACH) , information element (IE) , physical cell ID (PCID) .

It was agreed that UE can camp on an anchor cell. When the UE camps on the anchor cell, the UE can access a non-anchor cell (e.g., NES cell) by receiving system information (SIB or SSB and SIB) of the non-anchor cell from the anchor cell on which it camps.

The non-anchor cell can be a NES cell, which is a cell that supports the feature of network energy saving (NES) technologies.

UE will search an anchor cell or change the current anchor cell on which it camps to another anchor cell if certain criterion meets (e.g., the signal strength of the other anchor cell is stronger than the signal strength of the current anchor cell) . It is referred to as cell selection or reselection. When cell selection or reselection is performed, non-anchor cell (e.g., NES cell) was not considered.

This invention targets cell selection or reselection in which non-anchor cell (e.g., NES cell) is considered.

BRIEF SUMMARY

Methods and apparatuses for cell selection or reselection in an energy saving network are disclosed.

In one embodiment, a UE comprises a processor; and a transceiver coupled to the processor, wherein, the UE supports network energy saving (NES) , and the processor is configured to search a cell to be selected or reselected; and determine the cell to be selected or reselected in consideration of system information of the cell.

In some embodiment, the cell is an anchor cell, and the system information of the cell includes an indication to indicate at least one non-anchor cell, wherein, the system information of each of the at least one non-anchor cell can be requested from the anchor cell. The processor may be further configured to make a request for the system information of any concerned non-anchor cell. The request can be made before or after the cell is selected or reselected. In some embodiment, each non-anchor cell is identified by a starting index of Random Access Preamble (s) or by a cell ID. In some embodiment, the anchor cell is determined as the cell to be selected or reselected in consideration of the cell quality of the at least one non-anchor cell.

In some embodiment, the cell is a SIB-less cell, the processor is further configured to search and determine an anchor cell that provides the system information of the SIB-less cell. The processor may be further configured to determine that the SIB-less cell is not barred due to being unable to acquire the SIB1 according to one of: (1) the system information of the SIB-less cell can be received; (2) the SIB-less cell is indicated as not being barred; and (3) the SIB-less cell is in a predetermined frequency or a PCID of the SIB-less cell is a predetermined PCID.

In some embodiment, the processor is configured to search the cell to be selected or reselected if the cell quality of the current anchor cell is good and lower than a threshold.

In some embodiment, the UE camps on a first anchor cell with previous non-anchor cell (s) , the cell is a second anchor cell, and the second anchor cell is determined as the cell to be selected or reselected if the second anchor cell provides the system information of the previous non-anchor cell (s) .

In another embodiment, a method performed by a UE that supports network energy saving (NES) comprises searching a cell to be selected or reselected; and determining the cell to be selected or reselected in consideration of system information of the cell.

In still another embodiment, a network device comprises a processor; and a transceiver coupled to the processor, wherein, the network device manages an anchor cell, and the processor is configured to transmit, via the transceiver, to a UE, an indication that indicates at least one non-anchor cell, wherein, the system information of each of the at least one non-anchor cell can be requested from the anchor cell.

In some embodiment, the indication is included in the system information of the anchor cell.

In yet another embodiment, a method performed by a network device, wherein, the network device manages an anchor cell, and the method comprises transmitting, to a UE, an indication that indicates at least one non-anchor cell, wherein, the system information of each of the at least one non-anchor cell can be requested from the anchor cell.

BRIEF DESCRIPTION OF THE DRAWINGS

A more particular description of the embodiments briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only some embodiments, and are not therefore to be considered to be limiting of scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

Figures 1 (a) and 1 (b) illustrate two example scenarios of an anchor cell and two NES cells;

Figure 2 (a) illustrates the procedure of a first embodiment;

Figure 2 (b) illustrates the procedure of a variety of the first embodiment;

Figure 3 illustrates a first implementation of a second embodiment;

Figure 4 illustrates a scenario for a third embodiment;

Figure 5 is a schematic flow chart diagram illustrating an embodiment of a method;

Figure 6 is a schematic flow chart diagram illustrating a further embodiment of a method; and

Figure 7 is a schematic block diagram illustrating apparatuses according to one embodiment.

DETAILED DESCRIPTION

As will be appreciated by one skilled in the art that certain aspects of the embodiments may be embodied as a system, apparatus, method, or program product. Accordingly, embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc. ) or an embodiment combining software and hardware aspects that may generally all be referred to herein as a “circuit” , “module” or “system” . Furthermore, embodiments may take the form of a program product embodied in one or more computer readable storage devices storing machine-readable code, computer readable code, and/or program code, referred to hereafter as “code” . The storage devices may be tangible, non-transitory, and/or non-transmission. The storage devices may not embody signals. In a certain embodiment, the storage devices only employ signals for accessing code.

Certain functional units described in this specification may be labeled as “modules” , in order to more particularly emphasize their independent implementation. For example, a module may be implemented as a hardware circuit comprising custom very-large-scale integration (VLSI) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.

Modules may also be implemented in code and/or software for execution by various types of processors. An identified module of code may, for instance, include one or more physical or logical blocks of executable code which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but, may include disparate instructions stored in different locations which, when joined logically together, include the module and achieve the stated purpose for the module.

Indeed, a module of code may contain a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules and may be embodied in any suitable form and organized within any suitable type of data structure. This operational data may be collected as a single data set, or may be distributed over different locations including over different computer readable storage devices. Where a module or portions of a module are implemented in software, the software portions are stored on one or more computer readable storage devices.

Any combination of one or more computer readable medium may be utilized. The computer readable medium may be a computer readable storage medium. The computer readable storage medium may be a storage device storing code. The storage device may be, for example, but need not necessarily be, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

A non-exhaustive list of more specific examples of the storage device would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, random access memory (RAM) , read-only memory (ROM) , erasable programmable read-only memory (EPROM or Flash Memory) , portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.

Code for carrying out operations for embodiments may include any number of lines and may be written in any combination of one or more programming languages including an object-oriented programming language such as Python, Ruby, Java, Smalltalk, C++, or the like, and conventional procedural programming languages, such as the "C" programming language, or the like, and/or machine languages such as assembly languages. The code may be executed entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the very last scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN) , or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider) .

Reference throughout this specification to “one embodiment” , “an embodiment” , or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment” , “in an embodiment” , and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including” , “comprising” , “having” , and variations thereof mean “including but are not limited to” , unless otherwise expressly specified. An enumerated listing of items does not imply that any or all of the items are mutually exclusive, otherwise unless expressly specified. The terms “a” , “an” , and “the” also refer to “one or more” unless otherwise expressly specified.

Furthermore, described features, structures, or characteristics of various embodiments may be combined in any suitable manner. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that embodiments may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid any obscuring of aspects of an embodiment.

Aspects of different embodiments are described below with reference to schematic flowchart diagrams and/or schematic block diagrams of methods, apparatuses, systems, and program products according to embodiments. It will be understood that each block of the schematic flowchart diagrams and/or schematic block diagrams, and combinations of blocks in the schematic flowchart diagrams and/or schematic block diagrams, can be implemented by code. This code may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which are executed via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the schematic flowchart diagrams and/or schematic block diagrams for the block or blocks.

The code may also be stored in a storage device that can direct a computer, other programmable data processing apparatus, or other devices, to function in a particular manner, such that the instructions stored in the storage device produce an article of manufacture including instructions which implement the function specified in the schematic flowchart diagrams and/or schematic block diagrams block or blocks.

The code may also be loaded onto a computer, other programmable data processing apparatus, or other devices, to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the code executed on the computer or other programmable apparatus provides processes for implementing the functions specified in the flowchart and/or block diagram block or blocks.

The schematic flowchart diagrams and/or schematic block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of apparatuses, systems, methods and program products according to various embodiments. In this regard, each block in the schematic flowchart diagrams and/or schematic block diagrams may represent a module, segment, or portion of code, which includes one or more executable instructions of the code for implementing the specified logical function (s) .

It should also be noted that in some alternative implementations, the functions noted in the block may occur out of the order noted in the Figures. For example, two blocks shown in succession may substantially be executed concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more blocks, or portions thereof, to the illustrated Figures.

Although various arrow types and line types may be employed in the flowchart and/or block diagrams, they are understood not to limit the scope of the corresponding embodiments. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the depicted embodiment. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted embodiment. It will also be noted that each block of the block diagrams and/or flowchart diagrams, and combinations of blocks in the block diagrams and/or flowchart diagrams, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and code.

The description of elements in each Figure may refer to elements of proceeding figures. Like numbers refer to like elements in all figures, including alternate embodiments of like elements.

Reference will now be made in detail to some embodiments of the present application, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under specific network architecture and new service scenarios, such as 3GPP 5G, 3GPP LTE, 3GPP NR-U, NR Radio Access operating with shared spectrum channel access and so on. It is contemplated that along with the developments of network architectures and new service scenarios, all embodiments in the present application are also applicable to similar technical problems. Moreover, the terminologies recited in the present application may change, which should not affect the principle of the present application. Embodiments of the present disclosure can also be applied to unlicensed spectrum scenario.

To make description clearer, a few concepts are clarified.

NES UE can be also referred to a NES capable UE, or a UE that supports NES technologies, or a UE with the capability to support NES technologies.

An anchor cell is a cell where UE assumes that the cell transmits SSB, system information and paging. A non-anchor cell is a cell that at least does not transmit system information (SI) . In particular, a non-anchor cell is a cell that neither transmits SSB nor transmits SIBs, or a cell that transmits SSB but does not transmit SIB (s) (which can be referred to as SIB-less cell) . The SIB-less cell may transmit MIB or does not transmit MIB.

A NES cell is a cell that supports NES technologies.

Although an anchor cell can be a NES cell, in this disclosure, it is assumed that a NES cell is an example of non-anchor cell.

NES UE can identify or access to or connect to a non-anchor cell (e.g., NES cell) by obtaining the system information (e.g., SSB and/or SIB) of the non-anchor cell.

Figures 1 (a) and 1 (b) illustrate two example scenarios of an anchor cell and two non-anchor cells. In both Figures 1 (a) and 1 (b) , cell 1 is the anchor cell. Cell 1 has the system information of cell 2 and cell 3. Each of cell 2 and cell 3 is a non-anchor cell. In Figure 1 (a) , anchor cell 1 has the same coverage as each of non-anchor cell 2 and non-anchor cell 3. In Figure 1 (b) , each of anchor cell 1, non-anchor cell 2 and non-anchor cell 3 has a different coverage.

The anchor cell, which has the knowledge about the system information of non-anchor cell (s) (e.g., the non-anchor cell (s) that are the neighbor cells of the anchor cell) , can broadcast the system information of the non-anchor cell (s) .

A first embodiment relates to how the system information of the non-anchor cell is obtained by UE if the system information of the concerned non-anchor cell (s) is not broadcasted (or is not received by the UE) .

UE can send on-demand system information (SI) request for the system information of the concerned non-anchor cell (s) by including the identity of the concerned non-anchor cell (s) in the on-demand SI request.

According to the first embodiment, the UE can obtain the information on the system information of which non-anchor cell (s) can be requested from an anchor cell.

Figure 2 (a) illustrates the procedure of the first embodiment.

In step 210, the UE searches a cell to be selected or reselected. For example, an anchor cell that is the strongest cell can be searched as a cell to be selected or a candidate cell to be reselected (referred to as “candidate cell” hereinafter) . Incidentally, the strongest cell is the cell on a particular frequency that is considered strongest according to the layer 1 cell search procedure (specified in 3GPP TS 38.213 [4] , 3GPP TS 38.215 [11] ) .

In cell selection, it is generally described as that the UE searches a cell, although after the cell is searched, the cell is measured. In cell reselection, it is generally described as that the UE measures a cell or the UE measurements for cell selection and reselection purposes, although before measuring the cell, the cell may be searched within a certain frequency range (for example, the cell on a higher or lower priority frequency or the cell on an equal priority frequency) . In this disclosure, for simplicity, the description “UE searches a cell” can describe both cell selection and cell reselection.

In step 220, the UE reads the system information of the candidate cell. Only if the candidate cell is an anchor cell, the system information of the candidate cell can be directly obtained from the anchor cell.

The system information of the anchor cell includes, in addition to the system information of the anchor cell itself, an indication that indicates the system information of which non-anchor cell (s) can be requested from the anchor cell or will be broadcasted. It means that the indication indicates at least one non-anchor cell, wherein, the system information of the at least one non-anchor cell can be requested from the anchor cell. For example, in the example scenario illustrated in Figure 1 (a) or Figure 1 (b) , if cell 1, that is an anchor cell, is the candidate cell determined by the UE, the system information of cell 1 includes the system information of cell 1 itself as well as an indication that includes the identifications of non-anchor cell 2 and non-anchor cell 3, wherein, the system information of non-anchor cell 2 and of non-anchor cell 3 can be requested from the anchor cell 1 or will be broadcasted from the anchor cell 1. So, the UE can request for the system information of any concerned non-anchor cell (s) (if it is included in the indication) by sending on-demand SI request including the identity of the concerned non-anchor cell (s) to the anchor cell.

The identity of each non-anchor cell for which the system information can be requested included in the indication can be a starting index (e.g., ra-PreambleStartIndex-non-anchorcell) of Random Access Preamble (s) of the non-anchor cell (e.g., each of non-anchor cell 2 and non-anchor cell 3) .

Alternatively, the identity of each of the non-anchor cell (s) for which the system information can be requested can be a cell ID. For example, when the starting index is not partitioned among the non-anchor cell (s) for which the system information can be requested, each of the non-anchor cell (s) can be identified by the cell ID.

In addition, the set of Random Access Preambles and/or PRACH occasions of the non-anchor cell (s) for which the system information can be requested can be included in the indication.

In step 230, the UE selects or reselects (e.g., camps on) the anchor cell if it satisfies the legacy suitable cell definition or legacy acceptable cell definition. In legacy, a suitable cell is one for which the measured cell attributes satisfy the cell selection criteria; the cell PLMN is the selected PLMN, registered or an equivalent PLMN; the cell is not barred or reserved and the cell is not part of a tracking area which is in the list of “forbidden tracking areas for roaming” , while an acceptable cell is one for which the measured cell attributes satisfy the cell selection criteria and the cell is not barred.

In step 240, the UE may request for the system information of any concerned non-anchor cell (s) by sending on-demand SI request to the anchor cell.

Step 240 can be performed prior to step 230. It means that the UE may request, from the anchor cell, for the system information of any concerned non-anchor cell before the UE selects or reselects the anchor cell. Figure 2 (b) illustrates the procedure of a variety of the first embodiment, in which step 240 is performed before step 230 (improved as step 230’) .

If the system information of non-anchor cells is obtained by the UE prior to selecting or reselecting the anchor cell, the UE may consider the cell quality of non-anchor cells to determine whether to select or reselect the anchor cell. For example, if any non-anchor cell satisfies the legacy suitable cell definition or legacy acceptable cell definition (where the system information of the non-anchor cell is requested from the anchor cell) , the anchor cell can be selected or reselected. For another example, if any non-anchor cell is better than a configured threshold (where the system information of the non-anchor cell is requested from the anchor cell) , the anchor cell can be selected or reselected.

As a whole, in an improved step 230’, the UE can determine to select or reselect the anchor cell, if the anchor cell satisfies the legacy suitable cell definition or legacy acceptable cell definition, and/or if any non-anchor cell satisfies the legacy suitable cell definition or legacy acceptable cell definition; and/or if any non-anchor cell is better than a configured threshold.

Incidentally, if the UE determines that the system information of any concerned non-anchor cell is not changed, the UE may not request for the system information of this non-anchor cell. For example, in the example scenario illustrated in Figure 1 (a) or Figure 1 (b) , the UE already stores the system information of cell 2 and determines that the system information of cell 2 is not changed. In this condition, even if the UE knows from the system information of the anchor cell 1 that the system information of non-anchor cell 2 can be requested (and that the non-anchor cell 2 is a concerned non-anchor cell) , the UE may determine not to request, from the anchor cell 1, for the system information of non-anchor cell 2.

As a whole, according to the first embodiment, in the cell selection or reselection process, the UE can knows, from an indication included in the system information of the anchor cell, the system information of which non-anchor cell (s) can be obtained from the anchor cell. Accordingly, the UE can request for the system information of any concerned non-anchor cell (s) among the non-anchor cell (s) indicated in the indication.

According to the first embodiment, the UE can determine to select or reselect the anchor cell in consideration of the cell quality of the non-anchor cell (s) . That is, the system information of the anchor cell, that includes the information on the non-anchor cell (s) , the system information of which can be obtained from the anchor cell, is considered in determining to select or reselect the anchor cell.

A second embodiment relates to selecting a cell that can provide the system information of a SIB-less cell. As described above, the SIB-less cell is a cell that transmits SSB but does not transmit SIB (s) .

According to legacy principle, a cell may be treated as being “barred” (i.e., the cell status of the cell is “barred” ) if the SIB (e.g., SIB1) of the cell is unable to be acquired. That is, according to the legacy principle, even if a SIB-less cell is the strongest cell, the cell is still possibly treated as being “barred” . When a cell is treated as being “barred” , the barred cell shall be excluded from being a candidate cell for selection or reselection for up to 300 seconds according to legacy principle. So, the cell (e.g., SIB-less cell) that is searched as the strongest cell may be missed by the UE.

According to the second embodiment, the UE may select or reselect an anchor cell that transmits the system information of the SIB-less cell that is searched as the strongest cell. It means that the system information of the SIB-less cell that is the strongest cell can be obtained from the selected (or reselected) anchor cell.

Figure 3 illustrates a first implementation of the second embodiment.

In step 310, the cell indicates, e.g., in MIB (if the cell transmits MIB) or via the pattern of SSB, that it is a SIB-less cell. It means that the cell shall be treated as “barred” according to legacy principle. Incidentally, the ‘intraFreqReselection’ field in the MIB of the SIB-less cell may be set to “not allowed” , which means that the cell selection or reselection to intra-frequency cells (i.e., the cells that have the same frequency as the SIB-less cell) is not allowed when the highest ranked cell is barred, or treated as barred by the UE.

In step 320, when the UE searches a cell to be selected or reselected, if a SIB-less cell is searched for example because the SIB-less cell is the strongest cell, the UE searches other cell (s) that have the system information of the SIB-less cell on all possible frequencies including the same frequency as the SIB-less cell (which means that the UE ignores the ‘intraFreqReselection’ field set to “not allowed” ) .

In step 330, if the system information of the SIB-less cell can be received, e.g., by

steps

210, 220 and 240 in Figure 2 (b) , from the other anchor cell searched in step 320, the other anchor cell searched in step 320 is selected or reselected by the UE.

A second implementation of the second embodiment is described as follows.

In the first implementation of the second embodiment, the UE searches (and finds) a SIB-less cell that shall be “barred” . According to the second implementation of the second embodiment, a non-anchor cell that satisfies a predetermined condition can be indicated by an indication that the non-anchor cell is treated as barred or the existing cell status “barred” determination (s) is not applied, where the existing cell status “barred” determination is due to the system information (or necessary information for accessing the cell) not being able to be acquired. Incidentally, the necessary information for accessing the cell is a part of the system information that is enough to access the cell. The predetermined condition can be, for example, the non-anchor cell is in a predetermined frequency, or the PCID (physical cell ID) of the non-anchor cell is a predetermined PCID.

The indication can be indicated by one of the neighbor cells of the non-anchor. Alternatively, the indication can be indicated by the non-anchor in MIB or via the pattern of SSB. For example, when the UE’s RRC connection is released from the non-anchor cell, the indication can be indicated. Incidentally, the MIB and/or SIBs of the non-anchor can be stored by the UE.

A third implementation of the second embodiment is described as follows.

A non-anchor cell that satisfies a predetermined condition can be indicated as SIB-less cell. The predetermined condition can be, for example, the non-anchor cell is in a predetermined frequency, or the PCID (physical cell ID) of the non-anchor cell is a predetermined PCID.

When the UE searches a cell to be selected or reselected, if the MIB or SIBs of the non-anchor cell that satisfies the predetermined condition cannot be acquired, the UE will treat the non-anchor cell that satisfies the predetermined condition as not being barred due to being unable of acquiring the SIB1 (which means that the UE ignores the legacy principle that the cell is treated as being “barred” if the SIB (e.g., SIB1) of the cell is unable to be acquired) .

A fourth implementation of the second embodiment is described as follows.

When the UE searches a cell to be selected or reselected, if the MIB or SIBs of the non-anchor cell that satisfies the predetermined condition cannot be acquired, the UE will treat the non-anchor cell as not being barred.

After the system information of the non-anchor cell is acquired, the UE determines whether the non-anchor cell is barred based on the acquired system information.

A third embodiment relates to anchor cell change (i.e., cell reselection) .

Figure 4 illustrates a scenario, in which UE moves within the coverage of cell 2 that is a SIB-less cell. The UE obtains the system information of cell 2 from cell 1 that is the anchor cell, e.g., when the UE is located in the left edge of cell 2. Afterwards, the UE moves from the left edge of cell 2 to the right edge of cell 2. The UE cannot obtain the system information from cell 1 when it is located on the right edge of cell 2. When the UE is located on the right edge of cell 2, it can acquire the system information of cell 2 from cell 3 that is also an anchor cell.

According to a first implementation of the third embodiment, the UE reselects an anchor cell if the cell quality of the current anchor cell is lower than a threshold_out. Although the the cell quality of the current cell is lower than the threshold_out, the cell quality of the current cell is still considered good.

If the cell quality of the current anchor cell is lower than the threshold_out, the UE searches a cell meeting the following criteria: (1) the cell quality of the cell is higher than a threshold_in, and (2) the cell can provide the system information of the previous non-anchor cell (s) , where a previous non-anchor cell means that the system information of the previous non-anchor cell is received by the UE) . The UE reselects the cell meeting the criteria (1) and (2) .

It can be seen from the first implementation of the third embodiment that two new thresholds (i.e., threshold_out and threshold_in) are newly added, compared with legacy cell reselection procedure. The value of the thresholds (i.e., threshold_out and threshold_in) can be higher or lower than or equal to related legacy thresholds.

According to a second implementation of the third embodiment, the legacy cell reselection procedure is enhanced.

The UE, when camping on an anchor cell that can provide the system information (e.g., SSB and/or SIBs) of a previous non-anchor cell, performs legacy cell reselection by reselecting another anchor cell. According to the second implementation, the other anchor cell to be reselected is determined by the following manner:

(1) The cell can provide the system information (e.g., SSB and/or SIBs) of the previous non-anchor cell. If there are multiple previous non-anchor cells, the cell that can provide the system information of all previous non-anchor cells is better that the cell that can provide the system information of part of previous non-anchor cells; or the cell that can provide the system information of the UE-concerned non-anchor cell (s) is prioritized.

(2) The cell can provide the system information of the previous non-anchor cell, and the cell further satisfies the cell reselection criteria.

(3) If multiple cells meet the above criterion (1) or (2) , the cell that has the highest ranked among the multiple cells is prioritized.

(4) If multiple cells meet the above criterion (1) or (2) , in the condition that the highest-priority frequency is an NR frequency, the cell that has the highest ranked among the multiple cells on the highest priority frequency (ies) is prioritized.

(5) If no cell meets any of criterion (1) or (2) (which implies no cell meeting any of criterion (3) or (4) either) , the cell that satisfies the cell reselection criteria is determined.

The UE reselects (e.g., camps on) the determined cell.

Incidentally, if the reselected cell is determined according to (5) (which implies that the reselected cell does not provide the system information of the previous non-anchor cell (s) ) , the UE can use the system information (or necessary information for accessing the cell) of the previous non-anchor cells stored in the UE (if stored) .

Figure 5 is a schematic flow chart diagram illustrating an embodiment of a method 500 according to the present application. In some embodiments, the method 500 is performed by an apparatus, such as a remote unit (UE) . In certain embodiments, the method 500 may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

The method 500 may be performed by a UE that supports network energy saving (NES) , the method comprises 502 searching a cell to be selected or reselected; and 504 determining the cell to be selected or reselected in consideration of system information of the cell.

In some embodiment, the cell is an anchor cell, and the system information of the cell includes an indication to indicate at least one non-anchor cell, wherein, the system information of each of the at least one non-anchor cell can be requested from the anchor cell. The method may further comprise making a request for the system information of any concerned non-anchor cell. The request can be made before or after the cell is selected or reselected. In some embodiment, each non-anchor cell is identified by a starting index of Random Access Preamble (s) or by a cell ID. In some embodiment, the anchor cell is determined as the cell to be selected or reselected in consideration of the cell quality of the at least one non-anchor cell.

In some embodiment, the cell is a SIB-less cell, the method further comprises searching and determining an anchor cell that provides the system information of the SIB-less cell. The method may further comprise determining that the SIB-less cell is not barred due to being unable to acquire the SIB1 according to one of: (1) the system information of the SIB-less cell can be received; (2) the SIB-less cell is indicated as not being barred; and (3) the SIB-less cell is in a predetermined frequency or a PCID of the SIB-less cell is a predetermined PCID.

In some embodiment, the method comprises searching the cell to be selected or reselected if the cell quality of the current anchor cell is good and lower than a threshold.

Figure 6 is a schematic flow chart diagram illustrating a further embodiment of a method 600 according to the present application. In some embodiments, the method 600 is performed by an apparatus, such as a base unit or a network device. In certain embodiments, the method 600 may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

The method 600 may be performed by a network device, wherein, 602 the network device manages an anchor cell, and the method comprises 604 transmitting, to a UE, an indication that indicates at least one non-anchor cell, wherein, the system information of each of the at least one non-anchor cell can be requested from the anchor cell.

Referring to Figure 7, the UE (i.e., remote unit, or terminal device) includes a processor, a memory, and a transceiver. The processor implements a function, a process, and/or a method which are proposed in Figure 5.

The UE comprises a processor; and a transceiver coupled to the processor, wherein, the UE supports network energy saving (NES) , and the processor is configured to search a cell to be selected or reselected; and determine the cell to be selected or reselected in consideration of system information of the cell.

Referring to Figure 7, the gNB (i.e., base unit or network device) includes a processor, a memory, and a transceiver. The processor implements a function, a process, and/or a method which are proposed in Figure 6.

The network device comprises a processor; and a transceiver coupled to the processor, wherein, the network device manages an anchor cell, and the processor is configured to transmit, via the transceiver, to a UE, an indication that indicates at least one non-anchor cell, wherein, the system information of each of the at least one non-anchor cell can be requested from the anchor cell.

Layers of a radio interface protocol may be implemented by the processors. The memories are connected with the processors to store various pieces of information for driving the processors. The transceivers are connected with the processors to transmit and/or receive a radio signal. Needless to say, the transceiver may be implemented as a transmitter to transmit the radio signal and a receiver to receive the radio signal.

The memories may be positioned inside or outside the processors and connected with the processors by various well-known means.

In the embodiments described above, the components and the features of the embodiments are combined in a predetermined form. Each component or feature should be considered as an option unless otherwise expressly stated. Each component or feature may be implemented not to be associated with other components or features. Further, the embodiment may be configured by associating some components and/or features. The order of the operations described in the embodiments may be changed. Some components or features of any embodiment may be included in another embodiment or replaced with the component and the feature corresponding to another embodiment. It is apparent that the claims that are not expressly cited in the claims are combined to form an embodiment or be included in a new claim.

The embodiments may be implemented by hardware, firmware, software, or combinations thereof. In the case of implementation by hardware, according to hardware implementation, the exemplary embodiment described herein may be implemented by using one or more application-specific integrated circuits (ASICs) , digital signal processors (DSPs) , digital signal processing devices (DSPDs) , programmable logic devices (PLDs) , field programmable gate arrays (FPGAs) , processors, controllers, micro-controllers, microprocessors, and the like.

Embodiments may be practiced in other specific forms. The described embodiments are to be considered in all respects to be only illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

A user equipment (UE) , the UE comprising:

a processor; and

a transceiver coupled to the processor,

wherein, the UE supports network energy saving (NES) , and

the processor is configured to

search a cell to be selected or reselected; and

determine the cell to be selected or reselected in consideration of system information of the cell.
The UE of claim 1, wherein,

the cell is an anchor cell, and

the system information of the cell includes an indication to indicate at least one non-anchor cell, wherein, the system information of each of the at least one non-anchor cell can be requested from the anchor cell.
The UE of claim 2, wherein,

the processor is further configured to make a request for the system information of any concerned non-anchor cell.
The UE of claim 3, wherein,

the processor is configured to make the request before or after the cell is selected or reselected.
The UE of claim 2, wherein,

each non-anchor cell is identified by a starting index of Random Access Preamble (s) or by a cell ID.
The UE of claim 2, wherein,

the anchor cell is determined as the cell to be selected or reselected in consideration of the cell quality of the at least one non-anchor cell.
The UE of claim 1, wherein,

the cell is a system information block less (SIB-less) cell,

the processor is further configured to search and determine an anchor cell that provides the system information of the SIB-less cell.
The UE of claim 7, wherein,

the processor is further configured to determine that the SIB-less cell is not barred due to being unable to acquire the SIB1 according to one of:

the system information of the SIB-less cell can be received;

the SIB-less cell is indicated as not being barred; and

the SIB-less cell is in a predetermined frequency or a physical cell ID (PCID) of the SIB-less cell is a predetermined PCID.
The UE of claim 1, wherein,

the processor is configured to search the cell to be selected or reselected if the cell quality of the current anchor cell is good and lower than a threshold.
The UE of claim 1, wherein,

the UE camps on a first anchor cell with previous non-anchor cell (s) ,

the cell is a second anchor cell, and

the second anchor cell is determined as the cell to be selected or reselected if the second anchor cell provides the system information of the previous non-anchor cell (s) .
A method performed at a UE, wherein, the UE supports network energy saving (NES) ,

the method comprising:

searching a cell to be selected or reselected; and

determining the cell to be selected or reselected in consideration of system information of the cell.
A network device, comprising:

a processor; and

a transceiver coupled to the processor,

wherein, the network device manages an anchor cell, and

the processor is configured to

transmit, via the transceiver, to a UE, an indication that indicates at least one non-anchor cell, wherein, the system information of each of the at least one non-anchor cell can be requested from the anchor cell.
The network device of claim 12, wherein,

the indication is included in the system information of the anchor cell.