Method for hierarchical radio resource management and mobility management in mobile communications

Abstract

Various hierarchical radio resource management (RRM) and mobility management solutions are described. A device may receive a first reference signal (RS) from a coverage area. The first reference signal may include identification information of the coverage area. The apparatus may receive respective second reference signals from a plurality of network nodes within the coverage area, respectively. Each second reference signal may include identification information for a respective node of the plurality of network nodes. The apparatus may then perform a first measurement based on the first reference signal to determine whether to switch the traffic link from one coverage area to another coverage area; and performing a second measurement based on a second reference signal to select one or more network nodes from a network node set to form a service link, the network node set at least comprising the plurality of network nodes.

Description

[0001] Cross Reference to Related Applications

[0002] This application incorporates by reference in its entirety the contents of U.S. Patent Application 63 / 582,554 filed September 14, 2023 and U.S. Patent Application 63 / 582,552 filed September 14, 2023, from which this application claims priority as a non-provisional application. The contents of the above applications are incorporated by reference in their entirety. TECHNICAL FIELD

[0003] The present disclosure relates generally to mobile communications, and more specifically to hierarchical radio resource management (RRM) and mobility management for user equipment (UE) and network nodes in mobile communications. BACKGROUND

[0004] The methods described in this section are not prior art to the claims below merely by virtue of their inclusion in this section. Unless otherwise indicated herein, the methods described in this section are not prior art to the claims below merely by virtue of their inclusion in the section.

[0005] For current network implementations, one base station (BS) can consist of one or more cells to form a wireless access network to provide wireless coverage for a certain geographical area. The base station can support the operation of one or more cells, and each cell can serve at least one UE within its wireless coverage. To reduce inter-cell interference, the fifth generation (5 th Generation, 5G) New Radio (NR) supports multi-transmission reception point (TRP) architecture, which enables joint scheduling and transmission by allowing dynamic coordination among multiple TRPs. Thus, for example, a UE located at the edge of a cell can be served by multiple TRPs to improve its signal transmission and reception, thereby improving throughput.

[0006] However, there are some problems with the existing framework of radio resource management (RRM) and mobility management in 5G NR. For example, the current synchronization signal block (SSB) design is node-aware and beam-aware, where each TRP transmits its own SSB in a beam-swept manner, and the UE needs to perform beam sweeping to monitor the SSB from each TRP. Such SSB design not only causes increased UE power consumption (e.g., due to beamforming operations), but also causes inefficient radio resource utilization (e.g., due to different SSBs having essentially the same content except for the physical broadcast channel (PBCH) part). Moreover, such SSB design can cause resource contention between layer-1 (L1) measurements and layer 3 (L3) measurements, as L1 measurements and L3 measurements can need to monitor different SSBs on different beams at the same time.

[0007] Therefore, how to improve the framework of RRM and mobility management becomes an important issue for modern wireless communication systems. Thus, it is necessary to provide appropriate solutions to solve the above problems. SUMMARY

[0008] 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 some of the novel and non-obvious aspects of the technology described herein. The detailed description below further describes implementations of the technology described herein. Thus, the following summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in determining the scope of the claimed subject matter.

[0009] It is an object of the present application to propose solutions, concepts, designs, systems, methods, and apparatuses related to hierarchical RRM and mobility management. It is believed that by implementing one or more solutions described herein, the above problems can be avoided or mitigated.

[0010] In one aspect, a method can include a device (e.g., a UE) receiving a first reference signal (RS) (e.g., a single frequency network (SFN) SSB) from a coverage area (e.g., a SFN area), where the first RS contains identification information of the coverage area, and the coverage area contains at least one of: one or more cells, and one or more network nodes controlled by a distributed unit (DU). The method can further include the device receiving respective second RSs from a plurality of network nodes (e.g., TRPs) within the coverage area, where each second RS contains identification information of a respective node of the plurality of network nodes. The method can further include the device performing a first measurement based on the first RS to determine whether to switch a traffic link from the coverage area to another coverage area, and performing a second measurement based on the second RSs to select one or more network nodes from a set of network nodes to form the traffic link, where the set of network nodes contains at least the plurality of network nodes.

[0011] In one aspect, a method can include a network node (e.g., a TRP) within a coverage area transmitting a first RS (e.g., a SFN SSB) to a device (e.g., a UE), where the first RS contains identification information of the coverage area. The method can further include the network node transmitting a second RS (e.g., a TRP RS) to the device, where the second RS contains identification information of the network node. The method can further include the network node receiving, from the device, a first measurement value based on the first RS and a second measurement value based on the second RS, where the first measurement value is used to determine whether to switch a traffic link from the coverage area to another coverage area, and the second measurement value is used to select one or more network nodes from a set of network nodes to form the traffic link, where the set of network nodes contains the plurality of network nodes. The method can further include the network node performing mobility management for the device based on the first measurement value, the second measurement value, or a third measurement value of an uplink (UL) signal from the device.

[0012] It is worth noting that although the description provided by the present application can be based on certain wireless access technologies, networks, and network topologies, such as Long-Term Evolution (LTE), LTE-Advanced, LTE-Advanced Pro, 5G, NR, Internet-of-Things (IoT), Narrow Band Internet of Things (NB-IoT), Industrial Internet of Things (IIoT), beyond 5G (B5G), and 6 th Generation, 6G, the proposed concepts, solutions, and any variants / derivatives thereof can be applied to other types of wireless access technologies, networks, and network topologies. Therefore, the scope of the present application is not limited to the examples described in the present application. BRIEF DESCRIPTION OF DRAWINGS

[0013] The accompanying drawings are included to provide a further understanding of the present application, and are incorporated in and constitute a part of the present application. The drawings illustrate embodiments of the present application and, together with the description, serve to explain the principles of the present application. It is noted that the drawings may not be to scale as certain components can be shown disproportionately from size in order to clearly illustrate the concepts of the present application.

[0014] Figure 1 is a schematic diagram depicting an example scenario of existing RRM and mobility management framework in 5G NR.

[0015] Figure 2 is a schematic diagram depicting an example scenario of hierarchical RRM and mobility management framework according to an embodiment of the present application.

[0016] Figure 3 is a schematic diagram depicting an example scenario of mobility management based on hierarchical RRM framework according to an embodiment of the present application.

[0017] FIG. 4 is a schematic diagram depicting an example scenario of hierarchical RRM for idle mode or power saving mode UE mobility according to an embodiment of the present application.

[0018] FIG. 5 is a schematic diagram depicting an example scenario of hierarchical RRM for UE mobility in connected mode according to an embodiment of the present application.

[0019] FIG. 6 is a block diagram of an example communication system according to an embodiment of the present application.

[0020] FIG. 7 is a flowchart of an example process according to an embodiment of the present application.

[0021] FIG. 8 is a flowchart of an example process in accordance with an embodiment of the application. DETAILED DESCRIPTION

[0022] Detailed embodiments and implementations of the claimed subject matter are disclosed. It should be understood, however, that the disclosed embodiments and implementations are merely illustrative of the claimed subject matter that can be embodied in various forms. The application, however, can 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 this disclosure will be thorough and complete, and fully convey the scope of the application to those skilled in the art. In the following description, details of well-known features and techniques can be omitted to avoid unnecessarily obscuring the presented embodiments and implementations.

[0023] SUMMARY

[0024] Embodiments of the application relate to various techniques, methods, schemes, and / or solutions related to hierarchical RRM and mobility management. According to the application, many possible solutions can be implemented individually or jointly. That is, although these possible solutions will be described below separately, two or more of the possible solutions can be implemented in some combination.

[0025] In 5G NR, the existing RRM and mobility management framework is based on node and beam-aware SSB design. FIG. 1 illustrates one example scenario 100 of the existing RRM and mobility management framework in 5G NR. Part (A) of FIG. 1 depicts multiple TRPs 121-127 within a cell 120, where each TRP 121-127 transmits a respective SSB (denoted as SSB 1 through SSB 7, respectively) in a beam sweeping manner. Part (B) of FIG. 1 depicts the time and frequency resource allocation of the SSB transmissions of all TRPs within the cell 120. The SSBs of different TRPs are transmitted using different time domain resources within an SSB period. Part (C) of FIG. 1 depicts the SSB structure including primary synchronization signal (PSS) and secondary synchronization signal (SSS) for synchronization purposes, and PBCH containing demodulation reference signal (DMRS) and data. For example, the PSS and / or SSS can carry a cell identifier (ID) of the cell 120, and the PBCH can carry master information block (MIB) information and SSB index. For a user equipment (not shown in the figure) within the cell coverage, it can detect the following information from one or more SSBs: (i) cell ID to identify the cell 120; (ii) SSB index to identify a TRP; (iii) PBCH content other than SSB index information, which has been repeatedly transmitted multiple times and cannot be saved from transmission due to the beam sweeping architecture in frequency range 2 (FR2); and (iv) L1 / L3 measurement RS combined into one SSB. However, as mentioned previously, such SSB design not only causes UE power consumption increase (e.g., due to beamforming operation), but also causes low radio resource utilization (e.g., due to different SSBs having almost identical content except for the PBCH part). Furthermore, such SSB design can cause resource contention between L1 measurement and L3 measurement, as L1 measurement and L3 measurement can need to monitor different SSBs on different beams at the same time.

[0026] In view of the above, the present application proposes a series of solutions related to hierarchical RRM and mobility management, aiming to solve the above problems. According to the solutions of the present application, a hierarchical RRM and mobility management framework is provided to enhance the overall system performance of the UE and the NW in various operation modes, such as radio resource control (RRC) idle mode, power saving mode and RRC connected mode.

[0027] Figure 2 An example scenario 200 of the hierarchical RRM and mobility management framework according to an embodiment of the present application is shown. Figure 2 Part (A) of FIG. 2 shows an example scenario 200 of the hierarchical RRM and mobility management framework. FIG. 2 depicts a communication environment in which a UE 210 communicates wirelessly with one or more TRPs (e.g., radio units (RUs)) 221-227 within an SFN region 220, which provides the UE 210 with a first-layer RS, i.e., an SFN SSB. That is, all TRPs 221-227 transmit the same first-layer RS, whether or not beamforming is performed, as long as the beamforming is transparent to the UE. Specifically, the SFN SSB contains identification information of the SFN region 220. In addition to the SFN SSB, each TRP 221-227 also transmits a respective second-layer RS, i.e., a TRP RS. Specifically, the TRP RS contains identification information of the corresponding TRP (e.g., TRP ID). That is, the TRP-specific signal can identify the TRP but not the TRPs between different SFN regions. Figure 2Part (B) describes the time and frequency resource allocation for SFN SSB and TRP RS transmissions of all TRPs within SFN area 220, where SFN SSB and TRP RS are transmitted in different time-domain resources (e.g., TRP RS is transmitted after SFN SSB) to avoid resource contention between L1 and L3 measurements. UE 210 can perform (and report) L3 measurements based on SFN SSB to determine whether to switch a service link from SFN area 220 to another SFN area; it can also perform L1 measurements based on TRP RS to select one or more TRPs to form a service link, wherein the selected TRPs come from a set of TRPs containing at least TRPs 221-227. Therefore, the SFN control node (e.g., the DU that provides scheduling and / or radio resource coordination capabilities) can perform mobility management (e.g., inter-SFN mobility or intra-SFN TRP mobility) on the UE 210 based on L3 measurements, L1 measurements, or UL signal measurements (e.g., sounding reference signal (SRS) or physical random access channel (PRACH) signals) from the UE 210.

[0028] In some implementations, the SFN SSB may occupy a narrow bandwidth. For example, similar to the concepts of synchronization signal and PBCH in a 5G NR system, the SFN SSB may include the synchronization signal (or DU-specific RS) (e.g., both PSS and SSS are included, or only one of PSS and SSS) and the PBCH.

[0029] In some implementations, SFN SSB can be transmitted periodically. For example, SFN SSB can be transmitted periodically or semi-periodically.

[0030] In some implementations, the TRP RS may occupy narrow or wide bandwidth. For example, similar to the concept of synchronization signals in 5G NR systems, the TRP RS may include synchronization signals (e.g., SSS). The TRP RS may be a multi-port RS used for spatial domain parameter estimation / acquisition. The TRP RS PRS can be configured via, for example, broadcast information (or system information), such as in the form of a channel state information-reference signal (CSI-RS), thereby making the TRP RS's mode, resource element occupancy, and bandwidth more flexible. Furthermore, or alternatively, the TRP RS may be associated with multiple timings for each TRP, each timing corresponding to different spatial domain attributes.

[0031] Figure 3 illustrates an example scenario 300 of mobility management based on a hierarchical RRM framework according to an embodiment of the present invention. Scenario 300 describes two mobility types for the UE in the proposed hierarchical RRM and mobility management framework, including inter-SFN mobility and intra-SFN TRP mobility. Figure 3 As shown, UE 1 is moving between SFNs from SFN region 1 to SFN region 2, more specifically, from TRP 2 in SFN region 1 to TRP 3 in SFN region 2. Furthermore, UE 2 is moving between TRPs within SFN region 1 (i.e., from TRP 6 in SFN region 1 to TRP 2 in SFN region 1), while UE 3 is moving between TRPs within SFN region 2 (i.e., from TRP 6 in SFN region 2 to TRP 6 in SFN region 2).

[0032] In some implementations, SFN-to-SFN mobility of the UE in idle or power-saving mode can be based on the UE's measurement of the first-layer signal (i.e., SFN SSB). Alternatively, for connected mode, SFN-to-SFN mobility of the UE can be based on the UE's measurement of the first-layer signal (i.e., SFN SSB) and optionally on the measurement of the second-layer signal (i.e., TRP RS).

[0033] In some implementations, inter-TRP mobility within an SFN can be based on the UE's measurement of Layer 2 signals (i.e., TRP RS) or the network's measurement of the UE's uplink signals (e.g., SRS / PRACH signals). For intra-frequency scenarios, inter-TRP mobility within an SFN can be based on TRP RS (downlink-based) or SRS / PRACH (uplink-based). For inter-frequency scenarios, inter-TRP mobility within an SFN can be based on TRP RS (DL-based, requiring measurement gaps) (e.g., based on one port of the TRP RS if it's a multi-port signal) or PRACH (UL-based).

[0034] Figure 4 illustrates an example scenario 400 of a hierarchical RRM for UE mobility in idle mode or power-saving mode according to an embodiment of the present invention. Part (A) of Figure 4 depicts UE 410 wirelessly communicating with SFN control node 420 (e.g., DU or cell), where UE 410 is in idle mode or power-saving mode and moving within SFN area 421. It is noteworthy that TRPs within SFN area 421 are not shown in the figure because these TRPs are invisible or transparent to UE 410. This is because UE 410 only needs to monitor the SFN SSB in idle mode or power-saving mode, and all TRPs within SFN area 421 transmit the same SFN SSB containing information used to identify the cell, not the TRP. Part (B) of Figure 4 depicts the monitoring operation of UE 410, which focuses only on the SFN SSB, thereby reducing UE power consumption. An SFN SSB may include: (i) a DU-RS consisting of a PSS and / or an SSS, which is generated as a small number of sequences due to the assumption of wide cell coverage; and (ii) a PBCH containing minimal system information (SI). For example, an SFN SSB may be transmitted in a beamless manner in a high-frequency band (e.g., FR2 or FR3) and array gain may be compensated by long DU-RS+PBCH transmission. When operating in idle mode or power-saving mode, UE 410 may perform the following operations: (L3) SFN SSB measurement, initial access to a TRP using a common PRACH pool (the TRP may wake up during initial access), receiving a key SIB pointed to by the PBCH, or paging monitoring based on the common paging configuration in SFN area 421.

[0035] In some implementations, the layered RRM in scenario 400 can also be applied to enhanced mobile broadband (eMBB) idle mode UEs, reduced capability (ReCap) UEs, or NB IoT UEs.

[0036] In some implementations, the SFN SSB can employ beamforming methods transparent to the UE for transmission (e.g., using a small vertical subarray per TXRU, as in the low FR1 band, or using TRP-specific beamforming with TRP coverage in the FR2 or FR3 bands). For example, the subarray size can be chosen large enough that the angular coverage provided by directly applying a discrete Fourier transform (DFT) beamformer is too small. To utilize the transmit power of the power amplifiers connected to all antenna elements in the subarray, one embodiment designs one or more beamformers specifically for the subarray with cell-level angular coverage. This achieves cell-wide angular coverage and fully utilizes the transmit power capabilities of the subarray antenna element power amplifiers.

[0037] In some implementations, SFN-specific SIs (e.g., MIBs and necessary SIBs) can be provided for initial access, for example, through UE transparent beamforming via a TRP with cell-wide coverage. Optionally, multiple ports (e.g., 2 ports) can be used to implement, for example, a space frequency block code (SFBC) to increase diversity gain. To compensate for base station-side array gain, the transmission length of the SI (e.g., PBCH / MIB) may be longer than the symbol length of the connection-mode data channel. TRP RS configuration and / or RACH configuration can be predefined or provided in SFN-specific (broadcast) information.

[0038] In some implementations, the paging configuration for an SFN area can be public. For example, each TRP can transmit the same paging configuration via a cell-specific beam.

[0039] Figure 5 illustrates an example scenario 500 of a hierarchical RRM for connected-mode UE mobility according to the present invention. Part (A) of Figure 5 depicts a UE 510 wirelessly communicating with multiple TRSs (labeled TRPs 1-7), which are controlled by an SFN control node 520 (e.g., DU). The UE 510 operates in connected mode and moves between TRPs within an SFN region 521. Notably, TRPs within the SFN region 521 are shown in the figure because these TRPs are visible to the UE 510. The UE 510 needs to simultaneously monitor both the SFN SSB and the TRP RS in connected mode, and the TRP RS contains information for identifying the TRP. Figure 5 (B) depicts the monitoring operation of the UE 510, which primarily focuses on the SFN SSB and TRP RS. The specific ID of the TRP can be determined based on sequence detection. Specifically, the TRP RS and SFN SSB are time-division multiplexed (TDM), meaning the SFN SSB and TRP RS do not overlap in the time domain, thus avoiding resource contention between L1 and L3 measurements. Code-division multiplexed (CDM) is performed between TRP RSs of different TRPs. In connected mode, the UE 510 can perform the following operations: (L1) measurements of the TRP RS (e.g., multi-port TRP-RS for initial spatial domain parameter acquisition), TRP-RS-based mobility and TRP set selection (e.g., for supporting distributed multiple-input multiple-output (MIMO) operation), and beam acquisition / optimization during RACH.

[0040] In some implementations, the hierarchical RRM in scenario 500 can also be applied to eMBB connected mode UEs. For connected mode UEs, in order to maintain an independent service link with the selected TRP, it is necessary to continuously perform downlink (DL) and uplink (UL) synchronization using TRP-reference signals (TRP-RS) sent by each TRP. However, the propagation delay between different TRPs and the UE is different, and there may also be clock errors between different TRPs. Therefore, we need to designate a TRP as the primary reference point, which we call the primary TRP. Both the UE and the network need to know the primary TRP. The UE 510 can refer to the primary TRP to determine its own transmit power and transmission timing. Data sent to the UE 510 can be transmitted simultaneously by a set of TRPs within SFN area 521. The UE 510 can select this set of TRPs and the network will confirm the selection.

[0041] Exemplary Implementation

[0042] Figure 6 illustrates an example communication system 600 according to an embodiment of the present invention, which includes an example communication device 610 and an example network device 620. Both the communication device 610 and the network device 620 can perform various functions to implement the schemes, techniques, processes, and methods related to hierarchical RRM and mobility management described in this invention, including the scenarios / schemes described above and processes 700 and 800 described below.

[0043] The communication device 610 may be part of an electronic device, which may be a UE (e.g., eMBBUE), such as a portable or mobile device, a wearable device, a wireless communication device, or a computing device. For example, the communication device 610 may be integrated into a smartphone, smartwatch, personal digital assistant, vehicle electronic control unit (ECU), digital camera or tablet, laptop, or other computing device. The communication device 610 may also be part of a machine-type device, such as a ReCap UE, IoT, NB-IoT, eMTC, or IIoT user device, such as a fixed device, home device, roadside unit (RSU), wired communication device, or computing device. For example, the communication device 610 may be integrated into a smart thermostat, smart refrigerator, smart door lock, wireless speaker, or home control center. Alternatively, the communication device 610 may be implemented as one or more integrated circuit (IC) chips, such as, but not limited to, 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. The communication device 610 may include at least some of the components shown in FIG. 6, such as processor 612. The communication device 610 may also include one or more other components unrelated to the present invention (e.g., internal power supply, display device, and / or user interface device); therefore, for the sake of brevity, these components of the communication device 610 are not shown in FIG. 6 and are not described below.

[0044] Network device 620 may be part of an electronic device, and may be a network node in a wireless network, such as a TRP, RU, small cell, router, or gateway. For example, network device 620 may be implemented in a TRP / RU in a 4G / 5G / 6G, IoT, NB-IoT, or IIoT network. Alternatively, network device 620 may be implemented as one or more integrated circuit chips, such as, but not limited to, one or more single-core processors, one or more multi-core processors, or one or more RISC or CISC processors. Network device 620 may include at least some of the components shown in FIG. 6, such as processor 622. Network device 620 may also include one or more other components unrelated to the proposed embodiments of the present invention (e.g., internal power supply, display device, and / or user interface device), and therefore, for the sake of brevity, these components of network device 620 are not shown in FIG. 6 and are not described below.

[0045] On the one hand, both processor 612 and processor 622 can be implemented as one or more single-core processors, one or more multi-core processors, or one or more CISC processors. That is, although the present invention uses the singular term "processor" to refer to processor 612 and processor 622, according to the present invention, in some implementations, processor 612 and processor 622 may include multiple processors, while in other implementations, processor 612 and processor 622 may include a single processor. On the other hand, both processor 612 and processor 622 can be implemented in hardware (and optionally firmware), whose electronic components include, but are not limited to, 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 varactor diodes, which are configured and arranged according to the present invention to achieve a specific purpose. In other words, at least in some embodiments, processors 612 and 622 are both dedicated machines designed, arranged and configured to perform specific tasks, including hierarchical RRM and mobility management, in devices (e.g., communication device 610) and network nodes (e.g., network device 620) according to various embodiments of the invention.

[0046] In some embodiments, the communication device 610 may further include a transceiver 616 coupled to the processor 612, which is capable of wirelessly transmitting and receiving data. In some embodiments, the transceiver 616 may wirelessly communicate with different types of UEs and / or wireless networks with different radio access technologies (RATs) (e.g., 4G / 5G / B5G / 6G). In some embodiments, the transceiver 616 may be equipped with multiple antenna ports (not shown), such as four antenna ports. That is, the transceiver 616 may be equipped with multiple transmit antennas and multiple receive antennas for MIMO wireless communication. In some embodiments, the network device 620 may further include a transceiver 626 coupled to the processor 622. The transceiver 626 may include a transceiver capable of wirelessly transmitting and receiving data. In some embodiments, the transceiver 626 may wirelessly communicate with different types of UEs with different RATs. In some embodiments, the transceiver 626 may be equipped with multiple antenna ports (not shown), such as four antenna ports. In other words, transceiver 626 can be equipped with multiple transmit antennas and multiple receive antennas for MIMO wireless communication.

[0047] In some embodiments, the communication device 610 may further include a memory 614 coupled to the processor 612, which can be accessed by the processor 612 and stores data therein. In some embodiments, the network device 620 may further include a memory 624 coupled to the processor 622, which can be accessed by the processor 622 and stores data. Both memory 614 and memory 624 may include a random-access memory (RAM), such as dynamic random-access memory (DRAM), static random-access memory (SRAM), thyristor RAM (T-RAM), and / or zero-capacitor RAM (Z-RAM). Alternatively, both memory 614 and memory 624 may include a read-only memory (ROM), such as a mask ROM, a programmable ROM (PROM), an erasable programmable ROM (EPROM), and / or an electrically erasable programmable ROM (EEPROM). Alternatively, both memory 614 and memory 624 may include a non-volatile random-access memory (NVRAM), such as flash memory, solid-state memory, ferroelectric RAM (FeRAM), magnetoresistive RAM (MRAM), and / or phase-change memory.

[0048] Both communication device 610 and network device 620 can function as communication entities and are capable of communicating with each other using various proposed schemes according to the present invention. For ease of explanation, but not limited thereto, the functions of communication device 610 (as a UE) and network device 620 (as a network node (e.g., TRP or RU)) are described below through processes 700 and 800.

[0049] Exemplary process

[0050] Figure 7 illustrates an example process 700 according to an embodiment of the present invention. Process 700 may be an example implementation of the above-described scenario / scheme involving hierarchical RRM and mobility management, whether partially or fully implemented. Process 700 may represent one aspect of the functional implementation of communication device 610. Process 700 may include one or more operations, actions, or functions, as shown by one or more modules 710 to 740 in the figure. Although the modules shown in the figure are discrete, the individual modules of process 700 may be further subdivided, merged, or deleted according to the desired implementation. Furthermore, the individual modules of process 700 may be executed in the order shown in Figure 7 or in a different order. Process 700 may be implemented by communication device 610 or any suitable UE or machine type device. For ease of illustration and without limitation, process 700 is described below in the context of communication device 610. Process 700 may begin with step 710.

[0051] In step 710, process 700 may include the processor 612 of communication device 610 receiving a first RS (e.g., SFN SSB) from the coverage area via transceiver 616, wherein the first RS contains identification information of the coverage area. Process 700 may proceed from step 710 to step 720.

[0052] In step 720, process 700 may include processor 612 receiving a corresponding second RS (e.g., TRP RS) from each of a plurality of network nodes (e.g., TRPs) within the coverage area via transceiver 616, wherein each second RS contains identification information of each of the plurality of network nodes. Process 700 may proceed from 720 to 730.

[0053] In step 730, process 700 may include processor 612 performing a first measurement based on the first RS to determine whether to switch the service link from one coverage area to another. Process 700 may proceed from 730 to 740.

[0054] In step 740, process 700 may include processor 612 performing a second measurement based on the second RS to select one or more network nodes from a set of network nodes to form a service link, wherein the set of network nodes contains at least a plurality of network nodes.

[0055] In some embodiments, the coverage area may include at least one of the following: one or more cells; and one or more network nodes controlled by the DU.

[0056] In some embodiments, the first RS may include at least one of PBCH and PSS and SSS, or the first RS may not contain identification information of any of the multiple network nodes, or the first RS may be received in a periodic or semi-periodic manner.

[0057] In some embodiments, the bandwidth of the second RS may be less than that of the TRP-RS, or the second RS may be transmitted at one or more times, the one or more times corresponding to different spatial domain attributes.

[0058] In some embodiments, receiving the first RS can be performed when the communication device 610 is in idle mode or power-saving mode, or when the communication device 610 is an eMBB UE, ReCap UE, or NB IoT UE in idle mode. Alternatively, receiving the first RS and receiving the second RS can be performed when the communication device 610 is in connected mode, or when the communication device 610 is an eMBB UE in connected mode.

[0059] In some implementations, process 700 may also include processor 612 that, via transceiver 616, uses a pool of public PRACH resources within the coverage area to make initial access to one of the network nodes.

[0060] In some implementations, the PRACH pool can be predefined or configured via the PBCH of the first RS or the SIB indicated by the PBCH.

[0061] In some implementations, the sub-carrier spacing (SCS) of the first RS can be less than or equal to the sub-carrier spacing of the second RS, or the transmission bandwidth of the first RS can be less than or equal to the transmission bandwidth of the second RS, or the transmission symbol timing of the first RS can be greater than or equal to the transmission symbol timing of the second RS.

[0062] In some implementations, second RSs from different network nodes can be received in the same time-frequency resource, and the second RSs can perform CDM with each other, or the second RSs can be received after the first paging signal, or the second RSs can be predefined or configured via the PBCH of the first RS or via the SIB indicated by the PBCH.

[0063] In some implementations, process 700 may also include processor 612 receiving one or more identical SIBs indicated by the first RS from a network node via transceiver 616. Alternatively, process 700 may also include processor 612 receiving identical paging messages based on a public paging configuration within the coverage area from a network node via transceiver 616.

[0064] In some implementations, the coverage area can correspond to a DU or a cell, and each network node can be a TRP or RU.

[0065] Figure 8 illustrates an example process 800 according to an embodiment of the present invention. Process 800 may be an example implementation of the above-described scenario / scheme involving hierarchical RRM and mobility management, whether partially or fully implemented. Process 800 may represent one aspect of the functional implementation of network device 620. Process 800 may include one or more operations, actions, or functions, as shown by one or more modules 810 to 840 in the figure. Although shown in the form of discrete modules, the individual modules of process 800 may be further divided, merged, or deleted according to the desired implementation. Furthermore, the modules of process 800 may be executed in the order shown in Figure 8, or in a different order. Process 800 may be implemented by network device 620 or any suitable network node. For ease of illustration and without limitation, process 800 is described below in the context of network device 620. Process 800 may begin at step 810.

[0066] In step 810, process 800 may include the processor 622 of network device 620 sending a first RS (e.g., SFN SSB) to communication device 610 via transceiver 626, wherein the first RS contains identification information of the coverage area. Process 800 may proceed from 810 to 820.

[0067] In step 820, process 800 may include processor 622 sending a second RS (e.g., TRP RS) to communication device 610 via transceiver 626, wherein the second RS contains identification information of network device 620. Process 800 may proceed from 820 to 830.

[0068] In step 830, process 800 may include processor 622 receiving, via transceiver 626, a first measurement value based on a first RS and a second measurement value based on a second RS from communication device 610, wherein the first measurement value is used to determine whether to switch a service link from one coverage area to another, and the second measurement value is used to select one or more network nodes from a set of network nodes to form a service link, wherein the set of network nodes contains at least a plurality of network nodes. Process 800 may proceed from 830 to 840.

[0069] In step 840, process 800 may include processor 622 performing mobility management on communication device 610 based on a first measurement, a second measurement, or a third measurement of an uplink signal from communication device 610.

[0070] In some embodiments, the coverage area may include at least one of the following: one or more cells; and one or more network nodes controlled by the DU.

[0071] In some embodiments, the first RS may include at least one of PBCH and PSS and SSS; or the first RS may not contain identification information of any of the multiple network nodes; or the first RS may be received in a periodic or semi-periodic manner; or the first RS may be transmitted in a beamforming manner without beamforming or in a beamforming manner that is transparent to the communication device 610.

[0072] In some embodiments, the bandwidth of the second RS may be less than that of the TRP-RS; or the second RS may be a multi-port RS; or the second RS may be associated with one or more timings corresponding to different spatial domain characteristics.

[0073] In some embodiments, when the communication device 610 is in idle mode or power-saving mode, or when the communication device 610 is an eMBB UE, ReCap UE, or NB IoT UE in idle mode, the communication device 610 may receive the first RS. Alternatively, when the communication device 610 is in connected mode, or when the communication device 610 is an eMBB UE in connected mode, the communication device 610 may receive both the first RS and the second RS.

[0074] In some embodiments, process 800 may further include processor 622 receiving initial access from communication device 610 via transceiver 626 using a public PRACH pool within the coverage area.

[0075] In some embodiments, the PRACH pool can be predefined or configured via the PBCH of the first RS or the SIB indicated by the PBCH.

[0076] In some embodiments, the SCS of the first RS may be less than or equal to the SCS of the second RS, or the transmission bandwidth of the first RS may be less than or equal to the transmission bandwidth of the second RS, or the transmission symbol timing of the first RS may be greater than or equal to the transmission symbol timing of the second RS.

[0077] In some implementations, second RSs from different network nodes can be received in the same time-frequency resource, and the second RSs can perform CDM with each other, or the second RSs can be received after the first RS, or the second RSs can be predefined or configured via the PBCH of the first RS or via the SIB indicated by the PBCH.

[0078] In some implementations, process 800 may further include processor 622 sending one or more identical SIBs indicated by the first RS to communication device 610 via transceiver 626, wherein the SIBs may be identical to other SIBs sent by other network nodes within the coverage area. Alternatively, process 800 may further include processor 622 sending the same paging message to communication device 610 via transceiver 626 based on a common paging configuration within the coverage area, wherein the paging message may be identical to paging messages sent by other network nodes within the coverage area.

[0079] In some embodiments, the coverage area may correspond to a DU or a cell, and each network node may be a TRP or a RU.

[0080] Supplementary Explanation

[0081] The subject matter described in this invention sometimes illustrates different components contained within or connected to other components. It should be understood that the depicted architecture is merely an example, and many other architectures that achieve the same functionality can actually be implemented. Conceptually, any arrangement of components achieving the same function is effectively “associated” to achieve the desired function. Therefore, regardless of the architecture or intermediate components, any two components of this invention combined to achieve a specific function can be considered “associated” with each other to achieve the desired function. Similarly, any two such associated components can also be considered “operationally connected” or “operationally coupled” to achieve the desired function, and any two components that can be suchly associated can also be considered “operationally coupled” to achieve the desired function. Specific examples of operationally coupled components include, but are not limited to: physically mating and / or physically interacting components and / or wirelessly interacting components and / or logically interacting and / or logically interactable components.

[0082] Furthermore, regarding the extensive use of any plural and / or singular terms in this invention, those skilled in the art can, depending on the context and / or application, convert from plural to singular and / or from singular to plural. For clarity, various singular / plural interchanges can be explicitly described in this invention.

[0083] Furthermore, those skilled in the art will understand that, generally, the terminology used in this invention, and especially in the appended claims (e.g., the text of the appended claims), generally means "open" terms (e.g., the term "comprising" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "including" should be interpreted as "including but not limited to," etc.). Those skilled in the art will also understand that if a particular number of claims is intentionally enumerated, this intention will be explicitly listed in the claims, and if such enumeration is absent, this intention will not exist. For example, to aid understanding, the appended claims may include the use of the introductory phrases "at least one" and "one or more" that enumerate the claims. However, the use of such phrases should not be interpreted as implying that the introduction of the indefinite article "a" or "an" by a claim list limits any particular claim containing such an introduced claim list to an embodiment containing only one such list, even when the same claim includes the introductory phrase "one or more" or "at least one" and an indefinite article (such as "a" or "an"). (For example, "a" and / or "an" should be interpreted as meaning "at least one" or "one or more"); the same applies to the use of definite articles used to introduce claim lists. Furthermore, even when a specific number of introduced claim lists is explicitly listed, those skilled in the art will recognize that such a list should be interpreted as meaning at least the number listed (e.g., in the absence of other modifiers, an unmodified list of "two lists" means at least two lists, or two or more lists). Furthermore, in cases where the convention of "at least one of A, B, and C" is used, this interpretation generally means, as those skilled in the art will understand, that "a system having at least one of A, B, and C" includes, but is not limited to, systems having A alone, having B alone, having C alone, having A and B together, having A and C together, having B and C together, and / or having A, B, and C together. In cases where the convention of "at least one of A, B, or C" is used, this interpretation generally means, as those skilled in the art will understand, that "a system having at least one of A, B, or C" includes, but is not limited to, systems having A alone, having B alone, having C alone, having A and B together, having A and C together, having B and C together, and / or having A, B, and C together. Those skilled in the art will also understand that any transitional words and / or phrases that actually present two or more alternatives, whether in the specification, claims, or drawings, should be understood to contemplate the possibility of including one, any, or both of these items. For example, the phrase “A or B” would be understood to include the possibility of “A” or “B” or “A and B”.

[0084] Based on the foregoing, it will be understood that various embodiments of the invention have been described for illustrative purposes, and various modifications can be made without departing from the scope and spirit of the invention. Therefore, the various embodiments disclosed herein are not intended to be limiting, and the true scope and spirit are indicated by the appended claims.

Claims

1. A method comprising: The processor of the device receives a first reference signal (RS) from the coverage area, wherein the first reference signal contains identification information of the coverage area; The processor receives a second reference signal from each of a plurality of network nodes within the coverage area, wherein the second reference signal contains identification information of each of the plurality of network nodes; The processor performs a first measurement based on the first reference signal to determine whether to switch the service link from the coverage area to another coverage area; as well as The processor performs a second measurement based on the second reference signal to select one or more network nodes from a set of network nodes to form the service link, wherein the set of network nodes contains at least the plurality of network nodes.

2. The method of claim 1, wherein the coverage area comprises at least one of the following: One or more communities; and One or more network nodes controlled by a distributed unit (DU).

3. The method of claim 1, wherein: The first RS includes a physical broadcast channel (PBCH) and a primary synchronization signal (PSS) and / or a secondary synchronization signal (SSS). The first RS does not contain any network node identification information; or The first RS is received in a periodic or semi-periodic manner.

4. The method of claim 1, wherein: The bandwidth of the second RS is less than the bandwidth of the Transmit Receive Point (TRP) RS; The second RS is a multi-port RS; or The second RS is transmitted at one or more times, the one or more times corresponding to different spatial domain characteristics.

5. The method of claim 1, wherein: Receiving the first RS is performed when the device is in idle mode or power-saving mode, or when the device is an enhanced mobile broadband (eMBB) user equipment (UE), a low-capacity (ReCap) UE, or a narrowband (NB) Internet of Things (IoT) UE in idle mode; or Receiving the first RS and the second RS is performed when the device is in connected mode, or when the device is an eMBB UE in connected mode.

6. The method of claim 1, further comprising: The processor performs initial access to one of the network nodes using a pool of public Physical Random Access Channels (PRACH) within the coverage area.

7. The method of claim 5, wherein, The PRACH pool is predefined or configured via the PBCH of the first RS or the System Information Block (SIB) indicated by the BCH of the P.

8. The method of claim 1, wherein: The subcarrier spacing (SCS) of the first RS is less than or equal to the subcarrier spacing of the second RS; The transmission bandwidth of the first RS is less than or equal to the transmission bandwidth of the second RS; or The transmission symbol timing of the first RS is greater than or equal to the transmission symbol timing of the second RS.

9. The method of claim 1, wherein: The second RS from different network nodes is received in the same time-frequency resource, and the second RS performs code division multiplexing (CDM) on each other. The second RS is received after the first RS; or The second RS is predefined or configured via the PBCH of the first RS or via the SIB indicated by the PBCH.

10. The method of claim 1, further comprising: The processor receives one or more identical SIBs indicated by the first RS from the network node; or The processor receives the same paging message from the network node based on the public paging configuration within the coverage area.

11. A method comprising: A first reference signal (RS) is sent to the device by the processor of a network node within the coverage area, wherein the first RS contains identification information of the coverage area; The processor sends a second reference signal (RS) to the device, wherein the second RS contains identification information of the network node; The processor receives a first measurement value based on the first RS and a second measurement value based on the second RS from the device, wherein the first measurement value is used to determine whether to switch a service link from the coverage area to another coverage area, and the second measurement value is used to select one or more network nodes from a set of network nodes to form the service link, the set of network nodes containing multiple network nodes; as well as The processor performs mobility management on the device based on the first measurement, the second measurement, or a third measurement from the uplink (UL) signal of the device.

12. The method of claim 11, wherein the coverage area comprises at least one of the following: One or more communities; and One or more network nodes controlled by a distributed unit (DU).

13. The method of claim 11, wherein: The first RS includes a physical broadcast channel (PBCH) and at least one of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS); The first RS does not contain any of the identification information of the plurality of network nodes; The first RS transmits in a periodic or semi-periodic manner; or The first RS is transmitted in a beamforming-free or beamforming manner that is transparent to the device.

14. The method of claim 11, wherein: The bandwidth of the second RS is less than the bandwidth of the Transmit Receive Point (TRP) RS; The second RS is a multiport RS; or The second RS is transmitted at one or more times, the one or more times corresponding to different spatial domain characteristics.

15. The method of claim 11, wherein: When the device is in idle mode or power-saving mode, or when the device is an enhanced mobile broadband (eMBB) user equipment (UE), low-capacity (ReCap) UE, or narrowband (NB) Internet of Things (IoT) UE in idle mode, the first RS is received; or When the device is in connected mode, or when the device is an eMBB UE in connected mode, the device receives the first RS and the second RS.

16. The method of claim 11, further comprising: The processor receives initial access from the device using a pool of public Physical Random Access Channels (PRACH) within the coverage area.

17. The method of claim 15, wherein, The PRACH pool is predefined or configured to the device via the PBCH of the first RS or the System Information Block (SIB) indicated by the PBCH.

18. The method of claim 11, wherein: The subcarrier spacing (SCS) of the first RS is less than or equal to the subcarrier spacing (SCS) of the second RS; The transmission bandwidth of the first RS is less than or equal to the transmission bandwidth of the second RS; or The transmission symbol timing of the first RS is greater than or equal to the transmission symbol timing of the second RS.

19. The method of claim 11, wherein: The second RS from different network nodes is received in the same time-frequency resource, and the second RS is code-division multiplexed with each other (CDM); The second RS is received after the first RS; or The second RS is predefined or configured via the PBCH of the first RS or the SIB indicated by the PBCH.

20. The method of claim 11, further comprising: The processor sends one or more SIBs indicated by the first RS to the device, wherein the SIBs are the same as other SIBs sent by other network nodes within the coverage area; or The processor sends a paging message to the device based on a common paging configuration within the coverage area, wherein the paging message is the same as other paging messages sent by other network nodes within the coverage area.

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