Patent Publication Number: US-2023143475-A1

Title: Method And Apparatus For Enhancements On Paging Early Indication (PEI) Design

Description:
CROSS REFERENCE TO RELATED PATENT APPLICATION(S) 
     The present disclosure claims the priority benefit of U.S. Provisional Patent Application No. 63/275,977, filed on 5 Nov. 2021. The contents of aforementioned application are herein incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure is generally related to mobile communications and, more particularly, to enhancements on paging early indication (PEI) design. 
     BACKGROUND 
     Unless otherwise indicated herein, approaches described in this section are not prior art to the claims listed below and are not admitted as prior art by inclusion in this section. 
     Paging is a procedure a wireless network uses to find out the location of a UE, before the actual connection establishment. For example, paging may be used to alert the UE of an incoming session (call). In most cases, the paging process happens while the UE is in a radio resource control (RRC) idle mode. This means that UE has to monitor whether the network is sending any paging message to it and it has to spend some energy to run this “monitoring” process. In the RRC idle mode, the UE may enter or stay in a sleep mode defined in discontinuous reception (DRX) cycle. The UE may periodically wake up and monitor physical downlink control channel (PDCCH) to check for the presence of a paging message. If the PDCCH indicates that a paging message is transmitted in a subframe, then the UE may demodulate the paging channel to see if the paging message is directed to it. 
     In the current 5G new radio (NR) framework, LOOP operations (including automatic gain control (AGC), frequency tracking loop (FTL), and time tracking loop (TTL)) and measurements (MEAS) can only be performed in certain occasions, due to the synchronization signal block (SSB) transmission scheme in 5G NR. As a result, the gap between the SSBs for LOOP/MEAS and paging occasion (PO) is longer, and the UE may enter light sleep mode in the gap. If there is an indication before paging and the UE can monitor PO only if paging is indicated, then the UE can save power consumption not only for paging reception, but also for the light sleep between the SSBs and PO. However, there are some remaining issues regarding monitoring such indication. For example, when a PEI is delivered via a specific downlink control information (DCI) on PDCCH, size conflicts between the specific DCI and other DCIs may be caused. Therefore, a solution is sought to allow the UE to correctly decode the specific DCI and interpret the PEI therein. 
     SUMMARY 
     The following summary is illustrative only and is not intended to be limiting in any way. That is, the following summary is provided to introduce concepts, highlights, benefits and advantages of the novel and non-obvious techniques described herein. Select implementations are further described below in the detailed description. Thus, the following summary is not intended to identify essential features of the claimed subject matter, nor is it intended for use in determining the scope of the claimed subject matter. 
     An objective of the present disclosure is to propose solutions or schemes that address the aforementioned issues pertaining to enhancements on paging early indication (PEI) design. 
     In one aspect, a method may involve an apparatus receiving a PEI from a network node of a wireless network, wherein the PEI is included in a downlink control information (DCI) with a cyclic redundancy check (CRC) scrambled by a paging early indication-radio network temporary identifier (PEI-RNTI). The method may also involve the apparatus monitoring a paging occasion (PO) associated with the apparatus in a case that the PEI indicates there being a paging for a subgroup to which the apparatus belongs. 
     In one aspect, an apparatus may comprise a transceiver which, during operation, wirelessly communicates with a network node of a wireless network. The apparatus may also comprise a processor communicatively coupled to the transceiver. The processor, during operation, may perform operations comprising receiving, via the transceiver, a PEI from the network node of the wireless network, wherein the PEI is included in a DCI with a CRC scrambled by a PEI-RNTI. The processor may also perform operations comprising monitoring, via the transceiver, a PO associated with the apparatus in a case that the PEI indicates there being a paging for a subgroup to which the apparatus belongs. 
     It is noteworthy that, although description provided herein may be in the context of certain radio access technologies, networks and network topologies such as Long-Term Evolution (LTE), LTE-Advanced, LTE-Advanced Pro, 5th Generation (5G), New Radio (NR), Internet-of-Things (IoT) and Narrow Band Internet of Things (NB-IoT), Industrial Internet of Things (IIoT), and 6th Generation (6G), the proposed concepts, schemes and any variation(s)/derivative(s) thereof may be implemented in, for and by other types of radio access technologies, networks and network topologies. Thus, the scope of the present disclosure is not limited to the examples described herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of the present disclosure. The drawings illustrate implementations of the disclosure and, together with the description, serve to explain the principles of the disclosure. It is appreciable that the drawings are not necessarily in scale as some components may be shown to be out of proportion than the size in actual implementation in order to clearly illustrate the concept of the present disclosure. 
         FIG.  1    is a diagram depicting an example scenario under schemes in accordance with implementations of the present disclosure. 
         FIG.  2    is a diagram depicting an example scenario under schemes in accordance with implementations of the present disclosure. 
         FIG.  3    is a diagram depicting an example scenario under schemes in accordance with implementations of the present disclosure. 
         FIG.  4    is a block diagram of an example communication system in accordance with an implementation of the present disclosure. 
         FIG.  5    is a flowchart of an example process in accordance with an implementation of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED IMPLEMENTATIONS 
     Detailed embodiments and implementations of the claimed subject matters are disclosed herein. However, it shall be understood that the disclosed embodiments and implementations are merely illustrative of the claimed subject matters which may be embodied in various forms. The present disclosure may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments and implementations set forth herein. Rather, these exemplary embodiments and implementations are provided so that description of the present disclosure is thorough and complete and will fully convey the scope of the present disclosure to those skilled in the art. In the description below, details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the presented embodiments and implementations. 
     Overview 
     Implementations in accordance with the present disclosure relate to various techniques, methods, schemes and/or solutions pertaining to enhancements on paging early indication (PEI) design. According to the present disclosure, a number of possible solutions may be implemented separately or jointly. That is, although these possible solutions may be described below separately, two or more of these possible solutions may be implemented in one combination or another. 
     In 3 rd  Generation Partnership Project (3GPP), a radio access network (e.g., 5G NR access network) may include a plurality of base stations (e.g., Next Generation Node-Bs (gNBs)) to communicate with a plurality of mobile stations referred as user equipment (UEs). Paging is a procedure the wireless network uses to find out the location of a UE, before the actual connection establishment. For example, paging is used to alert the UE of an incoming session (e.g., a call). In most cases, the paging process happens while UE is in radio resource control (RRC) idle mode. This means that UE has to monitor whether the network is sending any paging message to it and it has to spend some energy to run this “monitoring” process. In RRC idle mode, a UE gets into and stays in a sleep mode defined in discontinuous reception (DRX) cycle. UE periodically wakes up and monitors physical downlink control channel (PDCCH) to check for the presence of a paging message. If the PDCCH indicates that a paging message is transmitted in a subframe, then the UE demodulates the signal received on the paging channel to see if the paging message is directed to it. 
     In 5G new radio (NR), an indication before paging, e.g., paging early indicator (PEI), is introduced to provide enhanced power saving for paging reception.  FIG.  1    illustrates an example scenario  100  under schemes in accordance with implementations of the present disclosure. As shown in scenario  100 , top diagram  110  depicts a paging reception procedure without PEI, while bottom diagram  120  depicts a paging reception procedure with PEI. Note that a subgroup of UEs may be associated with the same PO. During a conventional paging reception procedure in diagram  110 , a UE may periodically wake up and perform paging PDCCH decoding (denoted as  111  in  FIG.  1   ). If no UE in the UE subgroup is paged, then the UE may stop paging PDCCH decoding and enter the light sleep mode. Otherwise, if a UE in the UE subgroup is paged, the UE may perform paging physical downlink shared channel (PDSCH) decoding (denoted as  112  in  FIG.  1   ). If the UE itself is not paged, then the UE may stop paging PDSCH decoding and enter the deep sleep mode. Otherwise, the UE may perform connection establishment (denoted as  113  in  FIG.  1   ). During a novel paging reception procedure in diagram  120 , a UE may periodically wake up and check for PEI first (denoted as  121  in  FIG.  1   ). If no UE in the UE subgroup is paged, then the UE may stop PEI monitoring and enter the deep sleep mode. Otherwise, if a UE in the UE subgroup is paged, the UE may perform paging PDCCH decoding (denoted as  122  in  FIG.  1   ) as well as paging PDSCH decoding (denoted as  123  in  FIG.  1   ). If the UE itself is not paged, then the UE may stop paging PDSCH decoding and enter the deep sleep mode. Otherwise, if the UE itself is paged, the UE may perform connection establishment (denoted as  124  in  FIG.  1   ). 
     Under the novel paging reception procedure in diagram  120 , the UE can skip PO monitoring if the detected PEI indicates no paging (i.e., there is no paging for the UE&#39;s subgroup). The UE&#39;s main receiver is turned on in every paging cycle, for LOOP operations, measurements (MEAS), and PEI reception. If PEI indicates no paging, then after performing required measurements, the UE may turn off its main receiver and enter the deep sleep mode, e.g., until the next PEI. 
       FIG.  2    illustrates an example scenario  200  under schemes in accordance with implementations of the present disclosure. Scenario  200  illustrates the concept of providing PEI for additional power saving during paging reception. Diagram  210  depicts the synchronization signal block (SSB) transmission scheme in the paging reception procedure without PEI, where LOOP operations (including automatic gain control (AGC), frequency tracking loop (FTL), and time tracking loop (TTL)) and MEAS can only be performed in certain occasions, e.g., during SSB/TRS bursts. The UE wakes up for SSBs/TRSs, e.g., every 20 ms (every 2 radio frames). The UE may enter the light sleep mode in the gap between the SSBs/TRSs for LOOP/MEAS and the PO. 
     PEIs expected to be transmitted may be located near SSB bursts, thus aiming at power saving not only PO monitoring but also light sleep(s) and state transitions, when no UE is paged. A UE may need extra time for PEI monitoring in addition to SSB. In diagram  220 , a PEI is detected next to the SSB burst  221 . If the PEI indicates that there is no paging for the UE&#39;s subgroup (i.e., no paging), then the UE may enter deep sleep in  222 , e.g., entering the deep sleep mode in the gap from the reception of the PEI to the end of the corresponding PF. That is, with the PEI indicating no paging, the UE does not need to enter the light sleep mode and constantly wake up to receive the SSBs/TRSs in the gap between the PEI and the corresponding PF. Note that the UE may be required to perform intra-frequency or inter-frequency measurements when signal quality of the serving cell is below certain threshold. Usually, the UE performs the required measurements when it wakes up for paging monitoring (i.e., every paging cycle), then the UE may stay in the deep sleep mode, e.g., until next PEI. Since PEIs expected to be transmitted are located near SSB bursts, power saving can be achieved not only for PO monitoring but also for light sleep between the last SSB/PEI and the PO and state transitions (e.g., the power mode transition from/to normal mode to/from light sleep mode), when no UE in the UE group is paged. Note that Low-signal-to-interference-plus-noise ratio (Low-SINR) UEs need to wake up earlier, i.e., monitor more SSB bursts (larger N SSB ) before being able to decode a paging message. High-SINR UEs may wake up later before PO monitoring. Therefore, if there is only one PEI for each PO, PEI needs to be relatively early in order to cover a wide range of SINR values since a PEI serves many UEs. 
     It should be appreciated that, with the support of PEI, the UE&#39;s power saving may be enhanced. However, there are some remaining issues regarding PEI monitoring. For example, when a PEI is delivered via a specific downlink control information (DCI) on PDCCH, size conflicts between the specific DCI and other DCIs may be caused. Therefore, a solution is sought to allow the UE to correctly decode the specific DCI and interpret the PEI therein. 
     In view of the above, the present disclosure proposes a number of schemes pertaining to enhancements on PEI design. According to some schemes of the present disclosure, a new RNTI, called PEI-RNTI, is introduced and for a UE, the DCI including a PEI is provided with a CRC scrambled by the PEI-RNTI. By applying the schemes of the present disclosure, a UE may be able to correctly decode the DCI and interpret the PEI therein. In some implementations, the DCI including a PEI may be a DCI format 2_7. 
     According to some schemes of the present disclosure, the number of POs per PEI may be constant or variable in the wireless network.  FIG.  3    illustrates an example scenario  300  under schemes in accordance with implementations of the present disclosure. Scenario  300  illustrates examples of mapping between PEI and POs in a PF. As shown in scenario  300 , top diagram  310  depicts a constant PO number per PEI, while bottom diagram  320  depicts a variable PO number per PEI. In the current 5G NR framework, there may be one, two, or four POs in a PF. In diagram  310 , both the PEIs for UE-1 and UE-2 are mapped to (or associated with) two POs. In diagram  320 , the PEI for UE-1 is mapped to (or associated with) one PO, while the PEI for UE-2 is mapped to (or associated with) three POs. 
     According to some schemes of the present disclosure, the POs associated with a PEI may be located in one or more PFs. In some implementations, the one or more PFs may be adjacent or consecutive. That is, one PEI mapped to multiple POs across multiple consecutive PFs is supported. In some implementations, the total paging indication field size may still be up to 32 bits. 
     According to some schemes of the present disclosure, the DCI including a PEI (e.g., DCI format 2_7) may further include a tracking reference signal (TRS) availability indication which is in the same design as that for a paging DCI (e.g., DCI format 1_0). That is, the TRS availability indication may be transmitted by means of a DCI format 1_0 with a CRC scrambled by a paging-radio network temporary identifier (P-RNTI), or by means of a DCI format 2_7 with a CRC scrambled by a PEI-RNTI. The length of the TRS availability indication may be 1, 2, 3, 4, 5, or 6 bits, where the number of bits is equal to one plus the highest value of all the indBitID(s) provided by the TRS-ResourceSetConfig if configured (e.g., in a system information block (SIB)), or 0 bit otherwise. 
     Illustrative Implementations 
       FIG.  4    illustrates an example communication system  400  having an example communication apparatus  410  and an example network apparatus  420  in accordance with an implementation of the present disclosure. Each of communication apparatus  410  and network apparatus  420  may perform various functions to implement schemes, techniques, processes and methods described herein pertaining to enhancements on PEI design, including scenarios/schemes described above as well as process  500  described below. 
     Communication apparatus  410  may be a part of an electronic apparatus, which may be a UE such as a portable or mobile apparatus, a wearable apparatus, a wireless communication apparatus or a computing apparatus. For instance, communication apparatus  410  may be implemented in a smartphone, a smartwatch, a personal digital assistant, a digital camera, or a computing equipment such as a tablet computer, a laptop computer or a notebook computer. Communication apparatus  410  may also be a part of a machine type apparatus, which may be an IoT, NB-IoT, or IIoT apparatus such as an immobile or a stationary apparatus, a home apparatus, a wire communication apparatus or a computing apparatus. For instance, communication apparatus  410  may be implemented in a smart thermostat, a smart fridge, a smart door lock, a wireless speaker or a home control center. Alternatively, communication apparatus  410  may be implemented in the form of one or more integrated-circuit (IC) chips such as, for example and without limitation, one or more single-core processors, one or more multi-core processors, one or more reduced-instruction set computing (RISC) processors, or one or more complex-instruction-set-computing (CISC) processors. Communication apparatus  310  may include at least some of those components shown in  FIG.  4    such as a processor  412 , for example. Communication apparatus  410  may further include one or more other components not pertinent to the proposed scheme of the present disclosure (e.g., internal power supply, display device and/or user interface device), and, thus, such component(s) of communication apparatus  410  are neither shown in  FIG.  4    nor described below in the interest of simplicity and brevity. 
     Network apparatus  420  may be a part of an electronic apparatus, which may be a network node such as a base station, a small cell, a router or a gateway. For instance, network apparatus  420  may be implemented in an eNodeB in an LTE, LTE-Advanced or LTE-Advanced Pro network or in a gNB in a 5G, NR, IT, NB-IoT or IIoT network. Alternatively, network apparatus  420  may be implemented in the form of one or more IC chips such as, for example and without limitation, one or more single-core processors, one or more multi-core processors, or one or more RISC or CISC processors. Network apparatus  420  may include at least some of those components shown in  FIG.  4    such as a processor  422 , for example. Network apparatus  420  may further include one or more other components not pertinent to the proposed scheme of the present disclosure (e.g., internal power supply, display device and/or user interface device), and, thus, such component(s) of network apparatus  420  are neither shown in  FIG.  4    nor described below in the interest of simplicity and brevity. 
     In one aspect, each of processor  412  and processor  422  may be implemented in the form of one or more single-core processors, one or more multi-core processors, or one or more CISC processors. That is, even though a singular term “a processor” is used herein to refer to processor  412  and processor  422 , each of processor  412  and processor  422  may include multiple processors in some implementations and a single processor in other implementations in accordance with the present disclosure. In another aspect, each of processor  412  and processor  422  may be implemented in the form of hardware (and, optionally, firmware) with electronic components including, for example and without limitation, one or more transistors, one or more diodes, one or more capacitors, one or more resistors, one or more inductors, one or more memristors and/or one or more varactors that are configured and arranged to achieve specific purposes in accordance with the present disclosure. In other words, in at least some implementations, each of processor  412  and processor  422  is a special-purpose machine specifically designed, arranged and configured to perform specific tasks including autonomous reliability enhancements in a device (e.g., as represented by communication apparatus  410 ) and a network (e.g., as represented by network apparatus  420 ) in accordance with various implementations of the present disclosure. 
     In some implementations, communication apparatus  410  may also include a transceiver  416  coupled to processor  412  and capable of wirelessly transmitting and receiving data. In some implementations, communication apparatus  410  may further include a memory  414  coupled to processor  412  and capable of being accessed by processor  412  and storing data therein. In some implementations, network apparatus  420  may also include a transceiver  426  coupled to processor  422  and capable of wirelessly transmitting and receiving data. In some implementations, network apparatus  420  may further include a memory  424  coupled to processor  422  and capable of being accessed by processor  422  and storing data therein. Accordingly, communication apparatus  410  and network apparatus  420  may wirelessly communicate with each other via transceiver  416  and transceiver  426 , respectively. To aid better understanding, the following description of the operations, functionalities and capabilities of each of communication apparatus  410  and network apparatus  420  is provided in the context of a mobile communication environment in which communication apparatus  410  is implemented in or as a communication apparatus or a UE and network apparatus  420  is implemented in or as a network node of a communication network. 
     In some implementations, processor  412  may receive, via transceiver  416 , a PEI from the network apparatus  420 , wherein the PEI is included in a DCI with a CRC scrambled by a PEI-RNTI. Then, processor  412  may monitor, via transceiver  416 , a PO associated with the communication apparatus  410  in a case that the PEI indicates there being a paging for a subgroup to which the communication apparatus  410  belongs. 
     Illustrative Processes 
       FIG.  5    illustrates an example process  500  in accordance with an implementation of the present disclosure. Process  500  may be an example implementation of above scenarios/schemes, whether partially or completely, with respect to enhancements on PEI design. Process  500  may represent an aspect of implementation of features of communication apparatus  410 . Process  500  may include one or more operations, actions, or functions as illustrated by one or more of blocks  510  to  520 . Although illustrated as discrete blocks, various blocks of process  500  may be divided into additional blocks, combined into fewer blocks, or eliminated, depending on the desired implementation. Moreover, the blocks of process  500  may be executed in the order shown in  FIG.  5    or, alternatively, in a different order. Process  500  may be implemented by communication apparatus  410  or any suitable UE or machine type devices. Solely for illustrative purposes and without limitation, process  500  is described below in the context of communication apparatus  410 . Process  500  may begin at block  510 . 
     At  510 , process  500  may involve a processor (e.g., processor  412 ) of an apparatus (e.g., communication apparatus  410 ) receiving, via a processor (e.g., processor  412 ) of an apparatus (e.g., communication apparatus  410 ), a PEI from a network node (e.g., network apparatus  420 ), wherein the PEI is included in a DCI with a CRC scrambled by a PEI-RNTI. Process  500  may proceed from  510  to  520 . 
     At  520 , process  500  may involve the processor monitoring, via the transceiver, a PO associated with the apparatus in a case that the PEI indicates there being a paging for a subgroup to which the apparatus belongs. 
     In some implementations, the DCI may comprise a DCI format 2_7. 
     In some implementations, the PEI is associated with one or more POs in one or more PFs. 
     In some implementations, the number of the one or more POs may be constant per PEI in the wireless network. 
     In some implementations, the one or more PFs may be consecutive PFs. 
     In some implementations, the DCI may further comprise a TRS availability indication which is in the same design as that for a paging DCI. 
     In some implementations, the paging DCI may comprise a DCI format 1_0. 
     In some implementations, process  500  may further involve the processor performing, via the transceiver, at least one of a frequency tracking and a time tracking based on a TRS indicated by the DCI. 
     Additional Notes 
     The herein-described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected”, or “operably coupled”, to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being “operably couplable”, to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting components and/or wirelessly interactable and/or wirelessly interacting components and/or logically interacting and/or logically interactable components. 
     Further, with respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity. 
     Moreover, it will be understood by those skilled in the art that, in general, terms used herein, and especially in the appended claims, e.g., bodies of the appended claims, are generally intended as “open” terms, e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc. It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to implementations containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an,” e.g., “a” and/or “an” should be interpreted to mean “at least one” or “one or more;” the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number, e.g., the bare recitation of “two recitations,” without other modifiers, means at least two recitations, or two or more recitations. Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention, e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc. In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention, e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc. It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” 
     From the foregoing, it will be appreciated that various implementations of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various implementations disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.