UL Spatial Relationship Switching for PUCCH, PUSCH, and SRS

Abstract

Methods and apparatuses are provided for a UE to determine a UL spatial relation for UL transmission in response to a handover of an unknown UL spatial relation. The UE may determine whether the UL spatial relation is based on SRS transmission in UL, CSI-RS in DL, or SSB in DL. If the UL spatial relation is based on SRS transmission, the UE may select a UL spatial relation for the UL transmission corresponding to the Tx beam of the SRS transmission; if the UL spatial relation is based on the CSI-RS or the SSB, the UE may select a UL spatial relation for the UL transmission based on whether the handover of the unknown UL spatial relation is due to the corresponding resources for beam training not being configured by the communication network or the corresponding beam information having expired.

Description

Technical Field

[0001] This patent application generally relates to wireless communication systems and, more particularly, to uplink beam management. Background Art

[0002] Wireless mobile communication technologies use various standards and protocols to transfer data between a base station and wireless mobile devices. Wireless communication system standards and protocols can include the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE); the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard, which is commonly referred to by industry organizations as Worldwide Interoperability for Microwave Access (WiMAX); and the IEEE 802.11 standard for wireless local area networks (WLAN), which is commonly referred to by industry organizations as Wi-Fi. In the 3GPP radio access network (RAN) of an LTE system, a base station can include RAN nodes such as evolved universal terrestrial radio access network (E-UTRAN) Node B (also commonly denoted as evolved Node B, enhanced Node B, eNodeB, or eNB) and / or radio network controller (RNC) in E-UTRAN, and the base station communicates with wireless communication devices known as user equipment (UE). In a fifth-generation (5G) wireless RAN, the RAN nodes can include 5G nodes, new radio (NR) nodes, or gNodeB (gNB). As used herein, such base stations or nodes may also be referred to as transmission and reception points (TRP).

[0003] The RAN uses radio access technology (RAT) to communicate between RAN nodes and UEs. The RAN can include Global System for Mobile Communications (GSM), Enhanced Data Rate for GSM Evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), and / or E-UTRAN, which provide access to communication services through a core network. Each RAN in the RAN operates according to a specific 3GPP RAT. For example, GERAN implements GSM and / or EDGE RAT, UTRAN implements Universal Mobile Telecommunications System (UMTS) RAT or other 3GPP RAT, and E-UTRAN implements LTE RAT. Brief Description of the Drawings

[0004] To easily identify the discussion of any particular element or action, one or more of the most significant digits in the reference numerals refer to the drawing number in which the element was first introduced.

[0005] Figure 1 An example UL spatial relationship according to one embodiment is shown.

[0006] Figure 2 A method according to one embodiment is shown.

[0007] Figure 3 shows an example service-based architecture according to certain embodiments.

[0008] Figure 4 shows a UE according to one embodiment.

[0009] Figure 5 shows a network node according to one embodiment. DETAILED DESCRIPTION

[0010] NR is designed to support frequency bands from below 6 gigahertz (GHz) up to 100 gigahertz millimeter wave (mmWave) bands. Radio propagation in the mmWave band can experience higher attenuation than that experienced by lower frequency bands and can be more affected by blockages due to obstacles and foliage. To counteract these effects, NR uses beamforming to concentrate RF energy in the direction of the UE. Due to mobility and time-varying environments, the UE uses beam management procedures and beam recovery procedures to continuously search for new beams and dynamically change beams. The beam management procedure includes beam determination, beam measurement, beam reporting, and beam scanning. The beam recovery procedure may include beam failure detection, new beam identification, and beam recovery request.

[0011] Generally, downlink (DL) beam management includes initial coarse beam acquisition based on Synchronization Signal Block (SSB) or Channel State Indicator Reference Signal (CSI-RS) beams, DL transmission (Tx) beam refinement using narrower CSI beams, and DL reception (Rx) beam refinement at the UE. The TRP (e.g., gNB) may transmit the same CSI-RS beam to all UEs on multiple transmission occasions to refine their Rx beams. The SSB may be referred to as the Synchronization Signal (SS) Physical Broadcast Channel (PBCH) beam (SS / PBCH).

[0012] When the UE is transmitting the Uplink Control Channel (PUCCH), it may use the spatial relation information configured and activated by the network to determine the UL Tx beam. When the UE is transmitting the Uplink Data Channel (PUSCH), and for codebook-based transmission, the SRS resource indicator and precoding information given by DCI format 0_1 may determine the PUSCH transmission precoder. When the UE is transmitting the Uplink Data Channel (PUSCH), and for non-codebook-based transmission, the SRS resource indicator given by DCI format 0_1 may determine the PUSCH transmission precoder. When the UE is transmitting the Uplink Data Channel (PUSCH) scheduled by DCI format 0_0, the UE may use the same spatial relation as the PUCCH resource that has the lowest ID within the active UL BWP of the cell.

[0013] Figure 1 FIG. 100 shows an example UL spatial relationship for a TRP 102 and a UE 104 according to some embodiments. For UL beam management, the UE 104 is shown to be capable of configuring multiple Tx beams 106, and the TRP 102 (e.g., eNB) is shown to be capable of configuring multiple Rx beams 108. Similar to DL channel reception, UL channel or signal transmission from the UE 104 also requires a Tx beam 110 corresponding to the Rx beam 112 of the TRP 102 (i.e., UL spatial relationship) to reply. UL channels / signals include but are not limited to SRS (Sounding Reference Signal), PUCCH, and PUSCH.

[0014] For example, the UL spatial relationship for SRS can come from SSB or CSI-RS (downlink) or another SRS (uplink). The UL spatial relationship for PUCCH can come from SSB or CSI-RS (downlink) or another SRS (uplink). The UL spatial relationship for PUSCH can come from: a dedicated PUCCH with the lowest ID if the UL spatial relationship is scheduled by format 0_0 (uplink); or an SRS indicated by an SRI (SRS Resource Indicator) if the UL spatial relationship is scheduled by format 0_1 (uplink).

[0015] If the UL spatial relationship is unknown for those above-mentioned uplink signals or channels, UE-specific implementations can be designed. The UL spatial relationship can be unknown because no resources have been previously configured for the UE to train beams (e.g., the SRS spatial relationship is associated with a DL CSI-RS resource, but the network does not configure the CSI-RS resource before configuring the UE to use the spatial relationship for UL). The UL spatial relationship can also be unknown because the beam information has expired (e.g., the SRS spatial relationship is associated with a DL CSI-RS resource, but the UE made beam measurements for the CSI-RS a long time ago, and the beam information stored at the UE may have expired due to UE movement / rotation).

[0016] Therefore, solutions need to be designed to determine how to present the UL spatial relationship for SRS transmission for unknown spatial relationship handovers, where the SRS spatial relationship is called another SRS or the SRS spatial relationship is called CSI-RS or SSB. There is also a need to present the UL spatial relationship for PUCCH transmission for unknown spatial relationship handovers, where the PUCCH spatial relationship is called SRS or the PUCCH spatial relationship is called CSI-RS or SSB. In some embodiments, PUSCH may always refer to PUCCH or SRS, so there may be no unknown cases for PUSCH.

[0017] Exemplary implementation for SRS spatial relationship when the network does not configure resources for UE beam training 。

[0018] In one embodiment, if the SRS spatial relation is referred to as another SRS, the UE is configured to utilize the Tx beam from the other SRS in all cases. Otherwise, if the SRS spatial relation is referred to as CSI-RS or SSB, and if the UL spatial relation is unknown because the network has not configured resources for the UE to train the beam, the UE can be configured according to various alternative embodiments.

[0019] In a first alternative embodiment, the UE can utilize an Rx beam (or an active TCI (transmission configuration indicator)) for path loss RS reception to derive the corresponding Tx beam for the SRS. In this embodiment, the path loss RS (PL-RS) can be the on-use active path loss RS used by the UE for UL power control.

[0020] In a second alternative embodiment, the UE can utilize an Rx beam (or an active TCI (transmission configuration indicator)) for CORESET reception to derive the corresponding Tx beam for the SRS. In some such embodiments, if applicable, the CORESET is CORESET 0, otherwise it is the CORESET with the lowest ID. In other embodiments, the CORESET is the CORESET with the lowest ID. In still other embodiments, the CORESET is the most recent CORESET received by the UE before the UL spatial relation switch.

[0021] In a third alternative embodiment, the UE can utilize an Rx beam (or an active TCI (transmission configuration indicator)) for the most recent PL-RS and CORESET reception to derive the corresponding Tx beam for the SRS. In some such embodiments, the most recent PL-RS and CORESET reception is the most recent RL-RS reception or CORESET reception in the time domain before the UL spatial relation switch. Additionally, or in other embodiments, if applicable, the CORESET is CORESET 0, otherwise it is the CORESET with the lowest ID. In other embodiments, the CORESET is the CORESET with the lowest ID. In still other embodiments, the CORESET is the most recent CORESET received by the UE before the UL spatial relation switch.

[0022] In a fourth alternative embodiment, the UE can utilize the Tx beam of the RACH for the SRS. In some such embodiments, the Tx beam of the RACH can be derived from the DL RS (e.g., SSB or BFR-RS). In other embodiments, the Tx beam of the RACH can be derived from the last RACH transmission before the UL spatial relation switch.

[0023] In a fifth alternative embodiment, the UE may indicate or request the network to configure available resources for UL spatial relation switching. In some such embodiments, the indication or request may be carried on RRC signaling, or MAC PDUs, or L1 indications (e.g., UCI), or on the RACH.

[0024] In a sixth alternative embodiment, the UE may use any Tx beam to transmit the SRS.

[0025] In a seventh alternative embodiment, the UE may use the Rx beam for the best SSB (strongest) to derive the corresponding Tx beam for the SRS.

[0026] Exemplary implementation for PUCCH spatial relationship when the network does not configure resources for UE beam training 。

[0027] In one embodiment, if the SRS spatial relation is referred to as SRS, the UE may use the Tx beam from the SRS in all cases. Otherwise, if the PUCCH spatial relation is referred to as CSI-RS or SSB, and if the UL spatial relation is unknown because the network has not configured resources for the UE to train the beam, the UE may be configured according to various alternative embodiments.

[0028] In a first alternative embodiment, the UE may use the Rx beam (or the active TCI (transmission configuration indicator)) for path loss RS reception to derive the corresponding Tx beam for the PUCCH. In some such embodiments, the path loss RS (PL-RS) may be the active path loss RS in use by the UE for UL power control.

[0029] In a second alternative embodiment, the UE may use the Rx beam (or the active TCI (transmission configuration indicator)) for CORESET reception to derive the corresponding Tx beam for the PUCCH. In some such embodiments, if applicable, the CORESET is CORESET 0, otherwise it is the CORESET with the lowest ID. In other embodiments, the CORESET is the CORESET with the lowest ID. In still some other embodiments, the CORESET is the most recent CORESET received by the UE before UL spatial relation switching.

[0030] In a third alternative embodiment, the UE may use an Rx beam (or an active TCI (transmission configuration indicator)) for the nearest PL-RS and CORESET reception to derive the corresponding Tx beam for the PUCCH. In some such embodiments, the nearest PL-RS and CORESET reception includes the nearest RL-RS reception or CORESET reception in the time domain before the UL spatial relation switch. In some such embodiments, if applicable, the CORESET is CORESET 0, otherwise it is the CORESET with the lowest ID. In other embodiments, the CORESET is the CORESET with the lowest ID. In still some other embodiments, the CORESET is the nearest CORESET received by the UE before the UL spatial relation switch.

[0031] In a fourth alternative embodiment, the UE may use the Tx beam of the RACH for the PUCCH. In some such embodiments, the Tx beam of the RACH may be derived from a DL RS (e.g., SSB or BFR-RS). In other embodiments, the Tx beam of the RACH may be derived from the last RACH transmission before the UL spatial relation switch.

[0032] In a fifth alternative embodiment, the UE may indicate or request the network to configure the available resources for the UL spatial relation switch. In some such embodiments, the indication or request may be carried on the RRC signaling or MAC PDU or L1 indication (e.g., UCI) or RACH. Additionally, or in other embodiments, the UE may not transmit the PUCCH until the network configures the resources for the UE to obtain the UL spatial relation.

[0033] In a sixth alternative embodiment, the UE may use the Rx beam for the best SSB (strongest) to derive the corresponding Tx beam for the PUCCH.

[0034] In a seventh alternative embodiment, the UE may use the Rx beam of the active TCI for the latest PDSCH before the PUCCH.

[0035] In an eighth alternative embodiment, the UE may use the Tx beam for the PUSCH before the PUCCH. In some such embodiments, the PUSCH may be the last PUSCH before the PUCCH.

[0036] Exemplary implementation for SRS spatial relationship when beam information expires 。

[0037] In one embodiment, if the SRS spatial relation is referred to as another SRS, the UE may utilize the Tx beam from the other SRS in all cases. Otherwise, if the SRS spatial relation is referred to as CSI-RS or SSB, and if the UL spatial relation is unknown because the beam information has expired, the UE may be configured according to various alternative embodiments.

[0038] In a first alternative embodiment, the UE may utilize the Rx beam (or the active TCI (transmission configuration indicator)) for path loss RS reception to derive the corresponding Tx beam for the SRS. In this embodiment, the path loss RS (PL-RS) may be the active path loss RS in use by the UE for UL power control.

[0039] In a second alternative embodiment, the UE may utilize the Rx beam (or the active TCI (transmission configuration indicator)) for CORESET reception to derive the corresponding Tx beam for the SRS. In some such embodiments, if applicable, the CORESET is CORESET 0, otherwise it is the CORESET with the lowest ID. In other embodiments, the CORESET is the CORESET with the lowest ID. In still other embodiments, the CORESET is the most recent CORESET received by the UE before the UL spatial relation switch.

[0040] In a third alternative embodiment, the UE may utilize the Rx beam (or the active TCI (transmission configuration indicator)) for the most recent PL-RS and CORESET reception to derive the corresponding Tx beam for the SRS. In some such embodiments, the most recent PL-RS and CORESET reception is the most recent RL-RS reception or CORESET reception in the time domain before the UL spatial relation switch. Additionally or in other embodiments, if applicable, the CORESET is CORESET 0, otherwise it is the CORESET with the lowest ID. In other embodiments, the CORESET is the CORESET with the lowest ID. In still other embodiments, the CORESET is the most recent CORESET received by the UE before the UL spatial relation switch.

[0041] In a fourth alternative embodiment, the UE may utilize the Tx beam of the RACH for the SRS. In some such embodiments, the Tx beam of the RACH may be derived from the DL RS (e.g., SSB or BFR-RS). In other embodiments, the Tx beam of the RACH may be derived from the last RACH transmission before the UL spatial relation switch.

[0042] In a fifth alternative embodiment, the UE may not perform SRS transmission until it refines its Rx beam based on CSI-RS or SSB. In some such embodiments, additional Rx beam refinement delays may be expected during this process. In other embodiments, the UE may use the refined Rx beam to derive the corresponding Tx beam for this SRS transmission.

[0043] In a sixth alternative embodiment, the UE may perform SRS transmission using an outdated Tx beam. In some such embodiments, the network may determine whether the reception of this SRS from the UE is good. If the SRS reception at the network is not good, the network may reconfigure the UE to perform Rx / Tx beam refinement, or configure a new UL spatial relation RS for the UE. If the SRS reception at the network is good, the network may do nothing.

[0044] In a seventh alternative embodiment, the UE may trigger a RACH or a scheduling request to the network using error information to request a beam change. In some such embodiments, the network may reconfigure the UE to perform Rx / Tx beam refinement, or configure a new UL spatial relation RS to the UE.

[0045] In an eighth alternative embodiment, the UE may use the Rx beam for the best SSB (strongest) to derive the corresponding Tx beam for the SRS.

[0046] In a ninth alternative embodiment, the UE may indicate or request the network to reconfigure the available resources for UL spatial relation switching. In some such embodiments, this indication or request may be carried on RRC signaling or MAC PDU or L1 indication (e.g., UCI) or RACH.

[0047] In a tenth alternative embodiment, the UE may use any Tx beam to transmit the SRS.

[0048] In an eleventh alternative embodiment, the UE may use the Rx beam for the best SSB (strongest) to derive the corresponding Tx beam for the SRS.

[0049] Exemplary implementation for PUCCH spatial relationship when beam information expires 。

[0050] In one embodiment, if the PUCCH spatial relation is referred to as another SRS, the UE may use the Tx beam from the other SRS in all cases. Otherwise, if the PUCCH spatial relation is referred to as CSI-RS or SSB, and if the unknown UL spatial relation is due to expired beam information, the UE may be configured according to various alternative embodiments.

[0051] In a first alternative embodiment, the UE may use an Rx beam (or active TCI (transmission configuration indicator)) for path loss RS reception to derive a corresponding Tx beam for PUCCH. In some such embodiments, the path loss RS (PL-RS) may be the active path loss RS in use by the UE for UL power control.

[0052] In a second alternative embodiment, the UE may use an Rx beam (or active TCI (transmission configuration indicator)) for CORESET reception to derive a corresponding Tx beam for PUCCH. In some such embodiments, if applicable, the CORESET is CORESET 0, otherwise it is the CORESET with the lowest ID. In other embodiments, the CORESET is the CORESET with the lowest ID. In still other embodiments, the CORESET is the most recent CORESET received by the UE before the UL spatial relation switch.

[0053] In a third alternative embodiment, the UE may use an Rx beam (or active TCI (transmission configuration indicator)) for the most recent PL-RS and CORESET reception to derive a corresponding Tx beam for PUCCH. In some such embodiments, the most recent PL-RS and CORESET reception includes the most recent RL-RS reception or CORESET reception in the time domain before the UL spatial relation switch. In some such embodiments, if applicable, the CORESET is CORESET 0, otherwise it is the CORESET with the lowest ID. In other embodiments, the CORESET is the CORESET with the lowest ID. In still other embodiments, the CORESET is the most recent CORESET received by the UE before the UL spatial relation switch.

[0054] In a fourth alternative embodiment, the UE may use the Tx beam of the RACH for PUCCH. In some such embodiments, the Tx beam of the RACH may be derived from the DL RS (e.g., SSB or BFR-RS). In other embodiments, the Tx beam of the RACH may be derived from the last RACH transmission before the UL spatial relation switch.

[0055] In a fifth alternative embodiment, the UE may not perform PUCCH transmission until it refines its Rx beam based on CSI-RS or SSB. In some such embodiments, additional Rx beam refinement delay may be expected during this process. Additionally, or in other embodiments, the UE may use the refined Rx beam to derive a corresponding Tx beam for this PUCCH transmission.

[0056] In a sixth alternative embodiment, the UE may trigger a random access channel (RACH) or a scheduling request to the network using error information to request a beam change. In some such embodiments, the network may reconfigure the UE to perform Rx / Tx beam refinement, or configure a new UL spatial relation reference signal (RS) for the UE.

[0057] In a seventh alternative embodiment, the UE may use the Rx beam for the best SSB (strongest) to derive the corresponding Tx beam for the physical uplink control channel (PUCCH).

[0058] In an eighth alternative embodiment, the UE may indicate or request the network to reconfigure the available resources for UL spatial relation switching. In some such embodiments, the indication or request may be carried on radio resource control (RRC) signaling, a medium access control (MAC) protocol data unit (PDU), a layer 1 indication (e.g., uplink control information (UCI)), or a random access channel (RACH). Additionally, or in other embodiments, the UE may not transmit the PUCCH until the network reconfigures the resources for the UE to obtain the UL spatial relation.

[0059] In a ninth alternative embodiment, the UE may use the Rx beam of the transport channel state information (TCI) in use for the latest physical downlink shared channel (PDSCH) before the PUCCH.

[0060] In a tenth alternative embodiment, the UE may use the Tx beam for the physical uplink shared channel (PUSCH) before the PUCCH. In some such embodiments, the PUSCH may be the last PUSCH before the PUCCH.

[0061] Figure 2 is a flowchart illustrating a method for a UE to determine a UL spatial relation for UL transmission in response to an unknown UL spatial relation switch according to one embodiment. In block 202, method 200 determines whether the UL spatial relation is based on a sounding reference signal (SRS) transmission in the UL, a channel state indicator reference signal (CSI-RS) in the downlink (DL), or a synchronization signal block (SSB) in the DL. In block 204, if the UL spatial relation is based on an SRS transmission, method 200 selects the UL spatial relation for UL transmission corresponding to the transmission (Tx) beam of the SRS transmission. In block 206, if the UL spatial relation is based on a CSI-RS or an SSB, method 200 selects the UL spatial relation for UL transmission based on whether the unknown UL spatial relation switch is due to the corresponding resources for beam training not being configured by the communication network or the corresponding beam information having expired. In some such embodiments, the UL transmission may be an SRS or a PUCCH. Thus, the UE may be able to autonomously determine the SRS, PUCCH, or other UL signals or channels.

[0062] Exemplary system architecture

[0063] In some embodiments, the 5G system architecture supports data connectivity and services such that it enables the deployment to use technologies such as network function virtualization and software defined networks. The 5G system architecture may utilize service-based interactions between control plane network functions. Separating the user plane functions from the control plane functions allows for independent scalability, evolution, and flexible deployment (e.g., centralized location or distributed (remote) location). The modular function design allows for function reuse and enables flexible and efficient network slicing. Network functions and their network function services can interact directly or indirectly via a service communication proxy with another NF and its network function services. Another intermediate function may assist in routing control plane messages. The architecture minimizes the dependencies between the AN and the CN. The architecture may include an aggregated core network with a common AN-CN interface integrating different access types (e.g., 3GPP access and non-3GPP access). The architecture may also support a unified authentication framework, stateless NFs with decoupled computing resources and storage resources, capability exposure, concurrent access to local and centralized services (to support low-latency services and access to local data networks, where user plane functions may be deployed near the AN) and / or roaming with both home routed traffic and local breakout traffic in the visited PLMN.

[0064] The 5G architecture can be defined as service-based, and the interactions between network functions may include service-based representations, where network functions (e.g., AMF) within the control plane enable other authorized network functions to access their services. The service-based representation may also include point-to-point reference points. The reference point representation can also be used to show the interactions between NF services in network functions described by point-to-point reference points (e.g., N11) between any two network functions (e.g., AMF and SMF).

[0065] Figure 3 A service-based architecture 300 in 5GS according to one embodiment is shown. As described in 3GPP TS 23.501, the service-based architecture 300 includes NFs such as NSSF 302, NEF 304, NRF 306, PCF 308, UDM 310, AUSF 312, AMF 314, and SMF 316 for communicating with UE 320, (R)AN 322, UPF 324, and DN 326. The NFs and NF services can communicate directly (referred to as direct communication) or indirectly via SCP 318 (referred to as indirect communication). Figure 3 The corresponding service-based interfaces including Nutm, Naf, Nudm, Npcf, Nsmf, Nnrf, Namf, Nnef, Nnssf, and Nausf as well as reference points N1, N2, N3, N4, and N6 are also shown. Some example functions provided by the NFs shown in Figure 3 are described below.

[0066] The NSSF 302 supports functions such as: selecting a set of network slice instances for serving the UE; determining the allowed NSSAI and, if needed, determining the mapping to the subscribed S-NSSAI; determining the configured NSSAI and, if needed, determining the mapping to the subscribed S-NSSAI; and / or determining the set of AMFs to be used for serving the UE or, based on the configuration, possibly determining a list of candidate AMFs by querying the NRF.

[0067] The NEF 304 supports the exposure of capabilities and events. NF capabilities and events can be securely exposed by the NEF 304 (e.g., for third parties, application functions, and / or edge computing). The NEF 304 can use the standardized interface to the UDR (Nudr) to store / retrieve information as structured data. The NEF 304 can also securely provide information from external applications to the 3GPP network and can provide application functions to securely provide information to the 3GPP network (e.g., expected UE behavior, 5GLAN group information, and service-specific information), where the NEF 304 can authenticate and authorize and help restrict the application functions. The NEF 304 can provide the transformation of internal-external information by transforming between the information exchanged with the AF and the information exchanged with the internal network functions. For example, the NEF 304 transforms between the AF service identifier and the internal 5G core information (such as DNN and S-NSSAI). The NEF 304 can handle the masking of network and user-sensitive information for external AFs according to the network policy. The NEF 304 can receive information from other network functions (based on the exposure capabilities of other network functions) and store the received information as structured data using the standardized interface to the UDR. Then, the stored information can be accessed by the NEF 304 and re-exposed to other network functions and application functions and used for other purposes such as analysis. For the external exposure of services related to a specific UE, the NEF 304 can reside in the HPLMN. According to the operator agreement, the NEF 304 in the HPLMN can have an interface with the NFs in the VPLMN. When the UE is capable of switching between the EPC and the 5GC, the SCEF+NEF can be used for service exposure.

[0068] The NRF 306 supports the service discovery function by receiving NF discovery requests from NF instances or SCPs and providing the information of the discovered NF instances to NF instances or SCPs. The NRF 306 can also support P-CSCF discovery (a special case of SMF discovering AF), maintain the NF profiles of the available NF instances and the services they support, and / or notify subscribed NF service consumers or SCPs of newly registered / updated / deregistered NF instances along with their NF services. In the context of network slicing, multiple NRFs can be deployed at different levels based on the network implementation, such as at the PLMN level (the NRF is configured with information of the entire PLMN), the shared slice level (the NRF is configured with information belonging to a set of network slices), and / or the slice-specific level (the NRF is configured with information belonging to an S-NSSAI). In the context of roaming, multiple NRFs can be deployed in different networks, where the NRF in the visited PLMN (referred to as vNRF) is configured with information of the visited PLMN, and the NRF in the home PLMN (referred to as hNRF) is configured with information of the home PLMN, and the vNRF refers to the hNRF via the N27 interface.

[0069] The PCF 308 supports a unified policy framework to control network behavior. The PCF 308 provides policy rules for control plane functions to enforce them. The PCF 308 accesses subscription information related to policy decisions in the unified data repository (UDR). The PCF 308 can access the UDR located in the same PLMN as the PCF.

[0070] The UDM 310 supports generating 3GPP AKA authentication credentials, user identification processing (e.g., storage and management of the SUPI for each subscriber in the 5G system), unhiding of the privacy-protected subscription identifier (SUCI), access authorization based on subscription data (e.g., roaming restrictions), service NF registration management for the UE (e.g., storing the serving AMF for the UE, storing the serving SMF for the PDU session of the UE), service / session continuity (e.g., by maintaining the SMF / DNN allocation of the ongoing session), MT-SMS delivery, lawful interception function (especially in the case of outbound roaming where the UDM is the only contact point for LI), subscription management, SMS management, 5GLAN group management processing, and / or external parameter configuration (expected UE behavior parameters or network configuration parameters). To provide such functions, the UDM 310 uses subscription data (including authentication data) that can be stored in the UDR. In this case, the UDM implements the application logic and may not require an internal user data storage, and several different UDMs can serve the same user in different transactions. The UDM 310 can be located in the HPLMN of the subscriber it serves and can access the information of the UDR located in the same PLMN.

[0071] AF 328 interacts with the core network to provide services such as supporting the following: the impact of applications on traffic routing; accessing the NEF 304; interacting with the policy framework for policy control; and / or the interaction between IMS and 5GC. Based on the operator's deployment, application functions considered to be operator-trusted may be allowed to directly interact with relevant network functions. Application functions that the operator does not allow to directly access network functions can interact with relevant network functions via the NEF 304 using the external exposure framework.

[0072] The AUSF 312 supports authentication for 3GPP access and untrusted non-3GPP access. The AUSF 312 can also provide support for network slice-specific verification and authorization.

[0073] The AMF 314 supports the termination of the RAN CP interface (N2), the termination of the NAS (N1) for NAS encryption and integrity protection, registration management, connection management, reachability management, mobility management, lawful interception (for AMF events and the interface to the LI system), the transmission of SM messages between the UE and the SMF, transparent proxy for routing SM messages, access authentication, access authorization, the transmission of SMS messages between the UE and the SMSF, SEAF, location service management for regulatory services, the transmission of location service messages between the UE and the LMF and between the RAN and the LMF, EPS bearer ID allocation for EPS interworking, UE mobility event notification, control plane CIoT 5GS optimization, user plane CIoT 5GS optimization, configuring external parameters (expected UE behavior parameters or network configuration parameters) and / or network slice-specific verification and authorization. Some or all of the AMF functions may be supported in a single instance of the AMF 314. Regardless of the number of network functions, in some embodiments, there is only one instance of the NAS interface terminated at one of the network functions that implement at least NAS security and mobility management for each access network between the UE and the CN. The AMF 314 may also include policy-related functions.

[0074] In addition to the above functions, the AMF 314 may further include the following functions to support non-3GPP access networks: support for the N2 interface with N3IWF / TNGF, on which some information (e.g., 3GPP cell identifier) and procedures (e.g., handover-related) defined on 3GPP access may not be applicable, and non-3GPP access-specific information not applicable to 3GPP access may be applied; support for NAS signaling with the UE via N3IWF / TNGF, where some procedures supported by NAS signaling via 3GPP access may not be applicable to non-trusted non-3GPP (e.g., paging) access; support for the authentication of the UE connected via N3IWF / TNGF; management of the mobility, authentication, and separate security context states of the UE connected via non-3GPP access or simultaneously via 3GPP access or non-3GPP access; support for the coordinated RM management context valid on 3GPP access and non-3GPP access; and / or support for the dedicated CM management context for the UE to connect via non-3GPP access. It may not be necessary to support all of the above functions in the instance of a network slice.

[0075] The SMF 316 supports session management (e.g., session establishment, modification, and release, including tunnel maintenance between the UPF and the AN node), UE IP address allocation and management (including optional authorization) (where the UE IP address can be received from the UPF or from an external data network), DHCPv4 (server and client) and DHCPv6 (server and client) functions, functions for responding to Address Resolution Protocol requirements and / or IPv6 Neighbor Solicitation requests based on Ethernet PDU local cache information (e.g., the SMF responds to ARP and / or IPv6 Neighbor Solicitation requests by providing the MAC address corresponding to the IP address sent in the request), selection and control of the user plane function (including controlling the UPF to proxy ARP or IPv6 Neighbor Discovery or forwarding all ARP / IPv6 Neighbor Solicitation traffic to the SMF for the Ethernet PDU session), traffic steering configuration at the UPF to route traffic to the appropriate destination, 5G VN group management (e.g., maintaining the topology of the PSA UPFs involved, establishing and distributing N19 tunnels between the PSA UPFs, configuring traffic forwarding at the UPF to apply local handover, and / or forwarding based on N6 or N19), terminating the interface towards the Policy Control Function, lawful interception (for SM events and the interface to the LI system), charging for data collection and supporting the charging interface, controlling and coordinating the charging data collection at the UPF, terminating the SM part of the NAS message, downlink data notification, initiator of AN-specific SM information sent to the AN via the AMF over N2, determination of the SSC mode of the session, control plane CIoT 5GS optimization, header compression, acting as the I-SMF in a deployable / removable / repositionable I-SMF deployment, configuring external parameters (expected UE behavior parameters or network configuration parameters), P-CSCF discovery for IMS services, roaming functions (e.g., handling local enforcement to apply QoS SLA (VPLMN), charging data collection and charging interface (VPLMN), and / or lawful interception (in the VPLMN for SM events and the interface to the LI system), interacting with the external DN to transmit signaling for PDU session authentication / authorization by the external DN and / or indicating the UPF and the NG-RAN to perform redundant transmission on the N3 / N9 interface. Some or all of the SMF functions may be supported in a single instance of the SMF. However, in some embodiments, not all functions need to be supported in an instance of the network slice. In addition to the functions, the SMF 316 may include policy-related functions.

[0076] SCP 318 includes one or more of the following functions: indirect communication; delegated discovery; message forwarding and routing to destination NF / NF services; communication security (e.g., authorization for an NF service consumer to access an NF service manufacturer API), load balancing, monitoring, overload control, etc.; and / or optionally interact with the UDR to resolve the UDM group ID / UDR group ID / AUSF group ID / PCF group ID / CHF group ID / HSS group ID based on the UE identity (e.g., SUPI or IMPI / IMPU). Some or all of the SCP functions may be supported in a single instance of the SCP. In some embodiments, SCP 318 may be deployed in a distributed manner and / or more than one SCP may be present in the communication path between NF services. The SCP may be deployed at the PLMN level, shared slice level, and slice-specific level. The operator deployment may be left to ensure that the SCP can communicate with the relevant NRF.

[0077] UE 320 may include a device with radio communication capabilities. For example, UE 320 may include a smart phone (e.g., a handheld touchscreen mobile computing device that can connect to one or more cellular networks). UE 320 may also include any mobile or non-mobile computing device, such as a personal data assistant (PDA), pager, laptop computer, desktop computer, wireless handheld device, or any computing device including a wireless communication interface. The UE is also referred to as a client, mobile phone, mobile device, mobile terminal, user terminal, mobile unit, mobile station, mobile user, subscriber, user, remote station, access agent, user agent, receiver, radio equipment, reconfigurable radio equipment, or reconfigurable mobile device. UE 320 may include an IoT UE, which may include a network access layer for low-power IoT applications designed to utilize short-term UE connections. The IoT UE may exchange data with an MTC server or device via a PLMN, other UEs using ProSe or D2D communication, a sensor network, or an IoT network using technologies (e.g., M2M, MTC, or mMTC technologies). The M2M or MTC data exchange may be machine-initiated data exchange. The IoT network describes interconnected IoT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure). The IoT UE may execute background applications (e.g., keep-alive messages, status updates, etc.) to facilitate the connection to the IoT network.

[0078] The UE 320 may be configured to connect to or communicate with the (R)AN 322 via a radio interface 330, which may be a physical communication interface or layer configured to operate with cellular communication protocols such as GSM protocol, CDMA network protocol, Push-to-Talk (PTT) protocol, Cellular PTT (POC) protocol, UMTS protocol, 3GPP LTE protocol, 5G protocol, NR protocol, etc. For example, the UE 320 and the (R)AN 322 may use the Uu interface (e.g., the LTE-Uu interface) to exchange control plane data via a protocol stack including a PHY layer, a MAC layer, an RLC layer, a PDCP layer, and an RRC layer. DL transmissions may be from the (R)AN 322 to the UE 320, and UL transmissions may be from the UE 320 to the (R)AN 322. The UE 320 may also use a sidelink to directly communicate with another UE (not shown) for D2D, P2P, and / or ProSe communications. For example, the ProSe interface may include one or more logical channels, which include but are not limited to a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Discovery Channel (PSDCH), and a Physical Sidelink Broadcast Channel (PSBCH).

[0079] (R)AN 322 may include one or more access nodes, which may be referred to as base stations (BSs), Node Bs, evolved Node Bs (eNBs), next-generation Node Bs (gNBs), RAN nodes, controllers, transmission reception points (TRPs), etc., and may include a terrestrial station (e.g., a terrestrial access point) or a satellite station, which provides coverage within a geographical area (e.g., a cell). (R)AN322 may include one or more RAN nodes for providing macrocells, picocells, femtocells, or other types of cells. A macrocell may cover a relatively large geographical area (e.g., with a radius of several kilometers) and may allow unrestricted access by UEs with a service subscription. A picocell may cover a relatively small geographical area and may allow unrestricted access by UEs with a service subscription. A femtocell may cover a relatively small geographical area (e.g., a home) and may allow restricted access by UEs associated with the femtocell (e.g., UEs in a Closed Subscriber Group (CSG), UEs of users in a home, etc.).

[0080] Although not shown, multiple RAN nodes (such as (R)AN 322) may be used, where an Xn interface is defined between two or more nodes. In some specific implementations, the Xn interface may include an Xn user plane (Xn-U) interface and an Xn control plane (Xn-C) interface. The Xn-U may provide non-guaranteed delivery of user plane PDUs and support / provide data forwarding and traffic control functions. The Xn-C may provide management and error handling functions for managing the functions of the Xn-C interface; the mobility support for the UE 320 in the connected mode (e.g., CM-CONNECTED) includes functions for managing the UE mobility in the connected mode between one or more (R)AN nodes. This mobility support may include context transfer from an old (source) serving (R)AN node to a new (target) serving (R)AN node; and control of the user plane tunnel between the old (source) serving (R)AN node and the new (target) serving (R)AN node.

[0081] The UPF 324 may act as an anchor point for mobility within and between RATs, an external PDU session point interconnected with the DN 326, and a branching point for supporting multi-homed PDU sessions. The UPF 324 may also perform packet routing and forwarding, packet inspection, execute the user plane part of the policy rules, legally intercept packets (UP collection); traffic usage reporting, perform QoS processing on the user plane (e.g., packet filtering, gating, UL / DL rate enforcement), perform uplink traffic verification (e.g., SDF to QoS flow mapping), transport level packet marking in the uplink and downlink, and downlink packet buffering and downlink data notification triggering. The UPF 324 may include an uplink classifier for supporting routing traffic flows to the data network. The DN 326 may represent various network operator services, Internet access, or third-party services. The DN 326 may include, for example, an application server.

[0082] Figure 4 is a block diagram of a configurable exemplary UE 400 according to various embodiments of the present disclosure, including by executing instructions corresponding to any of the exemplary methods and / or processes described herein on a computer-readable medium. The UE 400 includes one or more processors 402, a transceiver 404, a memory 406, a user interface 408, and a control interface 410.

[0083] The one or more processors 402 may include, for example, an application processor, an audio digital signal processor, a central processing unit, and / or one or more baseband processors. Each of the one or more processors 402 may include internal memory and / or may include an interface for communicating with external memory (including memory 406). The internal or external memory may store software code, programs, and / or instructions for execution by the one or more processors 402 to configure and / or facilitate the UE 400 to perform various operations, including the operations described herein. For example, the execution of the instructions may configure the UE 400 to communicate using one or more wired or wireless communication protocols (including one or more wireless communication protocols standardized by 3GPP, such as those commonly referred to as 5G / NR, LTE, LTE-A, UMTS, HSPA, GSM, GPRS, EDGE, etc.) or any other current or future protocol that may be used in conjunction with the one or more transceivers 404, user interface 408, and / or control interface 410. As another example, the one or more processors 402 may execute program code stored in memory 406 or other memory corresponding to the MAC, RLC, PDCP, and RRC layer protocols standardized by 3GPP (e.g., for NR and / or LTE). As yet another example, the processor 402 may execute program code stored in memory 406 or other memory that, together with the one or more transceivers 404, implements corresponding PHY layer protocols, such as orthogonal frequency division multiplexing (OFDM), orthogonal frequency division multiple access (OFDMA), and single carrier frequency division multiple access (SC-FDMA).

[0084] Memory 406 may include memory regions for the one or more processors 402 to store variables used in the protocols, configurations, controls, and other functions of the UE 400 (including operations corresponding to or including any of the exemplary methods and / or processes described herein). In addition, memory 406 may include non-volatile memory (e.g., flash memory), volatile memory (e.g., static or dynamic RAM), or a combination thereof. In addition, memory 406 may interact with memory slots through which one or more formats of removable memory cards (e.g., SD cards, memory sticks, compact flash, etc.) may be inserted and removed.

[0085] The one or more transceivers 404 may include radio frequency transmitter and / or receiver circuitry that facilitates communication of the UE 400 with other devices that support similar wireless communication standards and / or protocols. For example, the one or more transceivers 404 may include switches, mixer circuitry, amplifier circuitry, filter circuitry, and synthesizer circuitry. Such RF circuitry may include a receive signal path having circuitry that down-converts an RF signal received from a front-end module (FEM) and provides a baseband signal to a baseband processor of one or more processors 402. The RF circuitry may also include a transmit signal path that may include circuitry for up-converting a baseband signal provided by the baseband processor and providing an RF output signal for transmission to the FEM. The FEM may include a receive signal path that may include circuitry configured to operate on an RF signal received from one or more antennas, amplify the received signal, and provide an amplified version of the received signal to the RF circuitry for further processing. The FEM may also include a transmit signal path that may include circuitry configured to amplify a transmit signal provided by the RF circuitry for transmission by one or more antennas. In various embodiments, amplification through the transmit or receive signal paths may be accomplished only in the RF circuitry, only in the FEM, or in both the RF circuitry and the FEM circuitry. In some embodiments, the FEM circuitry may include a TX / RX switch to switch between transmit mode and receive mode operation.

[0086] In some exemplary embodiments, the one or more transceivers 404 include transmitters and receivers that enable the device 1200 to communicate with various 5G / NR networks according to various protocols and / or methods proposed for standardization by 3GPP and / or other standards bodies. For example, such functionality may operate in cooperation with one or more processors 402 to implement the PHY layer based on OFDM, OFDMA, and / or SC-FDMA techniques, as described herein with reference to other figures.

[0087] The user interface 408 can take various forms according to specific embodiments, or may not exist in the UE 400. In some embodiments, the user interface 408 includes a microphone, a speaker, a slidable button, a pressable button, a display, a touchscreen display, a mechanical or virtual keypad, a mechanical or virtual keyboard, and / or any other user interface features commonly present on a mobile phone. In other embodiments, the UE 400 can include a tablet computing device with a larger touchscreen display. In such embodiments, one or more of the mechanical features of the user interface 408 can be replaced by equivalent or functionally equivalent virtual user interface features (e.g., virtual keypad, virtual buttons, etc.) implemented using the touchscreen display, as is familiar to those of ordinary skill in the art. In other embodiments, the UE 400 can be a digital computing device, such as a laptop computer, a desktop computer, a workstation, etc., that includes a mechanical keyboard that can be integrated, disassembled, or removable according to specific exemplary embodiments. Such digital computing devices can also include a touchscreen display. Many exemplary embodiments of the UE 400 with a touchscreen display are capable of receiving user input, such as input related to the exemplary methods and / or processes described herein or known to those of ordinary skill in the art.

[0088] In some exemplary embodiments of the present disclosure, the UE 400 includes an orientation sensor, which can be used in various ways by the features and functions of the UE 400. For example, the UE 400 can use the output of the orientation sensor to determine when the user has changed the physical orientation of the touchscreen display of the UE 400. The indication signal from the orientation sensor can be used in any application program executed on the UE 400, such that the application program can automatically change the orientation of the screen display (e.g., from portrait to landscape) when the indication signal indicates an approximately 90-degree change in the physical orientation of the device. In this way, the application program can keep the screen display in a user-readable manner regardless of the physical orientation of the device. Additionally, the output of the orientation sensor can be used in combination with various exemplary embodiments of the present disclosure.

[0089] The control interface 410 can take various forms according to specific embodiments. For example, the control interface 410 can include an RS-232 interface, an RS-485 interface, a USB interface, an HDMI interface, a Bluetooth interface, an IEEE (“FireWire”) interface, an I 2 C interface, a PCMCIA interface, etc. In some exemplary embodiments of the present disclosure, the control interface 1260 can include an IEEE 802.3 Ethernet interface, as described above. In some embodiments of the present disclosure, the control interface 410 can include an analog interface circuit that includes, for example, one or more digital-to-analog (D / A) converters and / or analog-to-digital (A / D) converters.

[0090] Those of ordinary skill in the art will recognize that the above list of features, interfaces, and radio communication standards is merely exemplary and not limited to the scope of the present disclosure. In other words, UE 400 may include more functions than Figure 4 shown, including, for example, video and / or still image cameras, microphones, media players, and / or recorders, etc. Additionally, the one or more transceivers 404 may include circuitry for communicating using additional radio communication standards including Bluetooth, GPS, and / or others. Further, the one or more processors 402 may execute software code stored in the memory 406 to control such additional functions. For example, the directional speed and / or position estimates output from a GPS receiver may be used in any application executed on UE 400, including the various exemplary methods and / or computer-readable media according to the various exemplary embodiments of the present disclosure.

[0091] Figure 5 is a block diagram of an exemplary configurable network node 500 according to various embodiments of the present disclosure, including by executing instructions corresponding to any of the exemplary methods and / or processes described herein on a computer-readable medium.

[0092] The network node 500 includes one or more processors 502, a radio network interface 504, a memory 506, a core network interface 508, and other interfaces 510. The network node 500 may include, for example, a base station, eNB, gNB, access node, or components thereof.

[0093] The one or more processors 502 can include any type of processor or processing circuitry and can be configured to execute one of the methods or processes disclosed herein. The memory 506 can store software code, programs, and / or instructions executed by the one or more processors 502 to configure the network node 500 to perform various operations, including the operations described herein. For example, execution of such stored instructions can configure the network node 500 to communicate with one or more other devices using protocols according to various embodiments of the present disclosure, including one or more of the methods and / or processes discussed above. Additionally, execution of such stored instructions can also configure and / or facilitate the network node 500 to communicate with one or more other devices using other protocols or protocol layers, such as one or more of the PHY, MAC, RLC, PDCP, and RRC layer protocols standardized by 3GPP for LTE, LTE-A, and / or NR, or any other higher layer protocol used in conjunction with the radio network interface 504 and the core network interface 508. By way of example and not limitation, the core network interface 508 includes the S1 interface, and the radio network interface 504 can include the Uu interface, as standardized by 3GPP. The memory 506 can also store variables used in the protocols, configurations, controls, and other functions of the network node 500. Thus, the memory 506 can include non-volatile memory (e.g., flash memory, hard disk, etc.), volatile memory (e.g., static or dynamic RAM), network-based (e.g., “cloud”) storage devices, or a combination thereof.

[0094] The radio network interface 504 can include a transmitter, a receiver, a signal processor, an ASIC, antennas, beamforming units, and other circuitry that enables the network node 500 to communicate with other equipment, such as, in some embodiments, a plurality of compatible user equipment (UE). In some embodiments, the network node 500 can include various protocols or protocol layers, such as the PHY, MAC, RLC, PDCP, and RRC layer protocols standardized by 3GPP for LTE, LTE-A, and / or 5G / NR. According to additional embodiments of the present disclosure, the radio network interface 504 can include a PHY layer based on OFDM, OFDMA, and / or SC-FDMA technologies. In some embodiments, the functions of such a PHY layer can be provided collaboratively by the radio network interface 504 and the one or more processors 502.

[0095] The core network interface 508 may include a transmitter, a receiver, and other circuitry that enables the network node 500 to communicate with other equipment in a core network (in some embodiments, such as a circuit-switched (CS) and / or packet-switched core (PS) network). In some embodiments, the core network interface 508 may include an S1 interface standardized by 3GPP. In some embodiments, the core network interface 508 may include one or more interfaces to one or more SGWs, MMEs, SGSNs, GGSNs, and other physical devices, and the one or more interfaces include functions known to those of ordinary skill in the art present in GERAN, UTRAN, E-UTRAN, and CDMA2000 core networks. In some embodiments, these one or more interfaces may be multiplexed together on a single physical interface. In some embodiments, the lower layers of the core network interface 508 may include one or more of asynchronous transfer mode (ATM), Internet protocol over Ethernet (IP), SDH over fiber optic, T1 / E1 / PDH over copper wire, microwave radio, or other wired or wireless transmission technologies known to those of ordinary skill in the art.

[0096] The other interface 510 may include a transmitter, a receiver, and other circuitry that enables the network node 500 to communicate with external networks, computers, databases, etc. for operating, managing, and maintaining the network node 500 or other network devices operatively connected thereto.

[0097] Embodiment

[0098] For one or more embodiments, at least one of the components shown in one or more of the foregoing figures may be configured to perform one or more of the operations, techniques, processes, and / or methods described in the following embodiments. For example, a baseband circuit or other processor or processing circuitry as described herein may be configured to operate in accordance with one or more of the following embodiments. As another example, the circuitry associated with a UE, a base station, a network element, etc. described above in connection with one or more of the foregoing figures may be configured to operate in accordance with one or more of the embodiments set forth below in the embodiments.

[0099] Embodiment 1 may include an apparatus that includes means for performing one or more elements of the methods described herein.

[0100] Embodiment 2 may include one or more non-transitory computer-readable media that include instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of the methods or processes described herein.

[0101] Example 3 may include an apparatus that includes logic components, modules, or circuits for performing one or more elements of the methods or processes described herein.

[0102] Example 4 may include a method, technique, or process according to or related to any one of Examples 1 to 3, or a part or component thereof.

[0103] Embodiment 5 may include an apparatus that includes: one or more processors and one or more computer-readable media, the one or more computer-readable media including instructions that, when executed by the one or more processors, cause the one or more processors to perform a method, technique, or process according to or related to any embodiment herein, or a part thereof.

[0104] Unless otherwise explicitly stated, any one of the above embodiments may be combined with any other embodiment (or combination of embodiments). The foregoing description of one or more specific embodiments provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise forms disclosed. Modifications and variations are possible in light of the above teachings, or may be acquired from practice of various embodiments.

[0105] Embodiments and specific implementations of the systems and methods described herein may include various operations, which may be embodied in machine-executable instructions to be executed by a computer system. The computer system may include one or more general-purpose or special-purpose computers (or other electronic devices). The computer system may include hardware components that include specific logic components for performing the operations, or may include a combination of hardware, software, and / or firmware.

[0106] It should be recognized that the systems described herein include a description of specific embodiments. These embodiments may be combined into a single system, partially incorporated into other systems, divided into multiple systems, or otherwise partitioned or combined. Additionally, it is contemplated that the parameters / attributes / aspects, etc. of one embodiment may be used in another embodiment. For clarity, these parameters / attributes / aspects, etc. are described in only one or more embodiments, and it should be recognized that unless specifically stated herein, these parameters / attributes / aspects, etc. may be combined with or replace the parameters / attributes, etc. of another embodiment.

[0107] Although the foregoing has been described in considerable detail for purposes of clarity, it will be apparent that certain changes and modifications may be made without departing from the principles of the invention. It should be noted that there are many alternative ways of implementing both the processes and the apparatus described herein. Accordingly, the embodiments of the invention should be regarded as illustrative rather than restrictive, and the specification is not limited to the details given herein but may be modified within the scope and equivalents of the appended claims.

Claims

1. A method for a user equipment (UE) to determine an uplink (UL) spatial relation for UL transmission in response to an unknown UL spatial relation handover, the method comprising: Determine whether the UL spatial relation is based on a sounding reference signal (SRS) transmission in the UL, a channel state indicator reference signal (CSI-RS) in the downlink (DL), or a synchronization signal block (SSB) in the DL; If the UL spatial relation is based on the SRS transmission, select the UL spatial relation for the UL transmission corresponding to the transmission (Tx) beam of the SRS transmission; If the UL spatial relation is based on the CSI-RS or the SSB, select the UL spatial relation for the UL transmission based on whether the unknown UL spatial relation switch is due to the corresponding resources for beam training not being configured by the communication network or the corresponding beam information having expired; And If the UL spatial relation is based on the CSI-RS or the SSB, select the UL spatial relation for the UL transmission corresponding to the Tx beam of the random access channel (RACH).

2. The method according to claim 1, wherein the UL transmission is selected from the group comprising sounding reference signal (SRS) or physical uplink control channel (PUCCH).

3. The method according to claim 1, further comprising: If the UL spatial relation is based on the CSI-RS or the SSB, use the receive (Rx) beam for receiving the path loss reference signal (PL-RS) or the active transmission configuration indicator (TCI) to derive the corresponding Tx beam for the UL transmission.

4. The method according to claim 3, wherein the PL-RS comprises an active path loss reference signal in use by the UE for UL power control.

5. The method according to claim 1, further comprising: If the UL spatial relation is based on the CSI-RS or the SSB, use the receive (Rx) beam for control resource set (CORESET) reception or the active transmission configuration indicator (TCI) to derive the corresponding Tx beam for the UL transmission.

6. The method according to claim 1, further comprising: If the UL spatial relation is based on the CSI-RS or the SSB, use the receive (Rx) beam for the most recent path loss reference signal (PL-RS) or control resource set (CORESET) reception or the active transmission configuration indicator (TCI) to derive the corresponding Tx beam for the UL transmission.

7. The method according to claim 6, wherein the most recent PL-RS or CORESET reception comprises a selected most recent RL-RS reception or CORESET reception in time domain before the unknown UL spatial relation handover.

8. The method according to any one of claims 5 to 7, wherein If applicable, the CORESET includes CORESET 0, otherwise the CORESET includes the selected CORESET with the lowest identifier.

9. The method according to any one of claims 5 to 7, wherein the CORESET comprises a CORESET with the lowest identifier.

10. The method according to any one of claims 5 to 7, wherein the CORESET comprises the most recent CORESET received by the UE in time domain before the unknown UL spatial relation handover.

11. The Tx beam of the RACH is derived from a downlink reference signal (RS) according to the method of claim 1.

12. The method according to claim 11, wherein the DL RS is selected from the group comprising the synchronization signal block (SSB) or beam failure recovery reference signal (BFR-RS).

13. The method according to claim 1, further comprising deriving the Tx beam of the RACH from the last RACH transmission in time domain before the unknown UL spatial relation handover.

14. The method according to claim 1, further comprising: If the UL spatial relation is based on the CSI-RS or the SSB, and if the UL transmission includes an SRS, use any Tx beam to transmit the UL transmission.

15. The method according to claim 1 further comprises: If the UL spatial relation is based on the CSI-RS or the SSB, use the receive (Rx) beam for the best or strongest CSI-RS or SSB to derive the corresponding Tx beam for the UL transmission.

16. The method according to claim 1 further comprises: If the UL spatial relation is based on the CSI-RS or the SSB, generate an indication or request to the communication network to configure or reconfigure the available resources for UL spatial relation switching.

17. The method according to claim 16, wherein the indication or request is carried on one or more of a Radio Resource Control (RRC) signal, a Medium Access Control (MAC) protocol data unit (PDU), uplink control information, or other L1 indication, and a Random Access Channel (RACH).

18. The method according to claim 16, wherein the UL transmission comprises a Physical Uplink Control Channel (PUCCH), and wherein the method further comprises not transmitting the PUCCH until the communication network configures or reconfigures the available resources for the UE to determine the UL spatial relationship.

19. The method according to claim 1 further comprises: If the UL spatial relation is based on the CSI-RS or the SSB, and if the UL transmission includes a physical uplink control channel (PUCCH), use the receive (Rx) beam for the active transmission configuration indicator (TCI) for the most recent physical downlink shared channel (PDSCH) in the time domain to determine the UL spatial relation for transmitting the PUCCH.

20. The method according to claim 1 further comprises: If the UL spatial relation is based on the CSI-RS or the SSB, and if the UL transmission includes a Physical Uplink Control Channel (PUCCH), then the Tx beam for the Physical Uplink Shared Channel (PUSCH) is used to determine the UL spatial relation for transmitting the PUCCH.

21. The method according to claim 20, wherein the PUSCH is the latest PUSCH that is before the PUCCH in the time domain.

22. The method according to claim 1 further comprises: If the UL spatial relation is based on the CSI-RS or the SSB, and if the corresponding beam information has expired, then the UL transmission is not performed until the UE refines the receive (Rx) beam based on the CSI-RS or the SSB.

23. The method according to claim 22 further comprises introducing an additional Rx beam refinement time period.

24. The method according to claim 22 further comprises using the refined Rx beam to derive a corresponding Tx beam for the UL transmission.

25. The method according to claim 1 further comprises: If the UL spatial relation is based on the CSI-RS or the SSB, and if the corresponding beam information has expired, then the expired beam information is used to perform the UL transmission.

26. The method according to claim 25, wherein the communication network determines whether the reception of the UL transmission from the UE is good, and wherein if the SRS reception at the communication network is not good, the communication network reconfigures the UE to perform Rx and Tx beam refinement or configures a new UL spatial relationship reference signal for the UE.

27. The method according to claim 1 further comprises: If the UL spatial relation is based on the CSI-RS or the SSB, and if the corresponding beam information has expired, then an error message is used to trigger a Random Access Channel (RACH) procedure or a scheduling request to the communication network to request a beam change.

28. The method according to claim 27, wherein the communication network reconfigures the UE to perform Rx or Tx beam refinement or configures a new UL spatial relationship reference signal for the UE according to the error information.

29. A device for network communication, the device comprising means for performing the method according to any one of claims 1 to 28.

30. A computer-readable medium, the computer-readable medium comprising instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform the method according to any one of claims 1 to 28.

31. A device for network communication, the device comprising logic components, modules or circuits for performing the method according to any one of claims 1 to 28.

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