UE-initiated handover of PDCCH links in single DCI scenarios

Abstract

An apparatus configured to: determine a quality of a first link with a first transmission point of a network node, where the first link is configured to carry a PDCCH; determining a quality of a second link with a second transmission point of the network node; determining to switch the PDCCH from the first link to a second link; and sending, to the network node, a request to switch the PDCCH from the first link to the second link. An apparatus configured to: receive, from a user equipment (UE), a request to switch a PDCCH from a first link to a second link, where the first link is provided via a first transmission point, where the second link is provided via a second transmission point; and sending, to the user equipment, an acknowledgement of a request to switch the PDCCH from the first link to the second link.

Description

Technical Field

[0001] The example and non-limiting embodiments generally relate to links used for PDCCH transmission in a multi-TRP configuration, and more specifically to the switching of PDCCH links. Background Technology

[0002] In cellular communications, it is known to use the transmission configuration indication state to configure gNB transmission information for the UE. Summary of the Invention

[0003] The following overview is intended to be illustrative only. The content of this invention is not intended to limit the scope of the claims.

[0004] According to one aspect, an apparatus includes: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: determine the quality of a first link with a first transmission point to a network node, wherein the first link is configured to carry a physical downlink control channel; determine the quality of a second link with a second transmission point to the network node; determine to switch the physical downlink control channel from the first link to the second link; and send a request to the network node via the first link to switch the physical downlink control channel from the first link to the second link.

[0005] According to one aspect, a method includes: using a user equipment to determine the quality of a first link with a first transmission point to a network node, wherein the first link is configured to carry a physical downlink control channel; determining the quality of a second link with a second transmission point to the network node; determining to switch the physical downlink control channel from the first link to the second link; and sending a request to the network node to switch the physical downlink control channel from the first link to the second link.

[0006] According to one aspect, an apparatus includes components for: determining the quality of a first link with a first transmission point to a network node, wherein the first link is configured to carry a physical downlink control channel; determining the quality of a second link with a second transmission point to the network node; determining to switch the physical downlink control channel from the first link to the second link; and sending a request to the network node to switch the physical downlink control channel from the first link to the second link.

[0007] According to one aspect, a non-transitory computer-readable medium includes program instructions stored thereon for performing at least the following operations: determining the quality of a first link with a first transmission point to a network node, wherein the first link is configured to carry a physical downlink control channel; determining the quality of a second link with a second transmission point to the network node; determining to switch the physical downlink control channel from the first link to the second link; and causing a request to be sent to the network node to switch the physical downlink control channel from the first link to the second link.

[0008] According to one aspect, an apparatus includes: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: receive from a user equipment a request to switch a physical downlink control channel from a first link to a second link, wherein the first link is provided via a first transmission point and the second link is provided via a second transmission point; and send to the user equipment an acknowledgment of the request to switch the physical downlink control channel from the first link to the second link.

[0009] According to one aspect, a method includes: using a network node, receiving from a user equipment a request to switch a physical downlink control channel from a first link to a second link, wherein the first link is provided via a first transmission point and the second link is provided via a second transmission point; and sending an acknowledgment to the user equipment of the request to switch the physical downlink control channel from the first link to the second link.

[0010] According to one aspect, an apparatus includes components for: receiving from a user equipment a request to switch a physical downlink control channel from a first link to a second link, wherein the first link is provided via a first transmission point and the second link is provided via a second transmission point; and sending to the user equipment an acknowledgment of the request to switch the physical downlink control channel from the first link to the second link.

[0011] According to one aspect, a non-transitory computer-readable medium includes program instructions stored thereon for performing at least the following operations: causing a user equipment to receive a request to switch a physical downlink control channel from a first link to a second link, wherein the first link is provided via a first transmission point and the second link is provided via a second transmission point; and causing an acknowledgment to be sent to the user equipment of the request to switch the physical downlink control channel from the first link to the second link.

[0012] The independent claims provide the subject matter for several aspects. Additional aspects are defined in the dependent claims. Attached Figure Description

[0013] The foregoing aspects and other features are explained in the following description taken in conjunction with the accompanying drawings, wherein:

[0014] Figure 1 This is a block diagram of one possible and non-limiting example system in which exemplary embodiments can be practiced;

[0015] Figure 2 This is a schematic diagram illustrating the features described herein;

[0016] Figure 3 This is a schematic diagram illustrating the features described herein;

[0017] Figure 4 This is a schematic diagram illustrating the features described herein;

[0018] Figure 5 This is a schematic diagram illustrating the features described herein;

[0019] Figure 6 This is a schematic diagram illustrating the features described herein;

[0020] Figure 7 This is a schematic diagram illustrating the features described herein;

[0021] Figure 8 This is a schematic diagram illustrating the features described herein;

[0022] Figure 9 This is a schematic diagram illustrating the features described herein;

[0023] Figure 10 It is a flowchart illustrating the steps described herein; and

[0024] Figure 11 This is a flowchart illustrating the steps described in this article. Detailed Implementation

[0025] The following abbreviations, which may be found in the specification and / or drawings, are defined as follows: 3GPP Third Generation Partnership Project 5G (Fifth Generation) 5GC 5G Core Network ACK confirmation AMF Access and Mobility Management Functions AoA Angle of Arrival AoD Departure Angle BFD Beam Fault Detection BFD-RS Beam Fault Detection Reference Signal BM-RS Beam Management Reference Signal CBD Candidate Beam Detection CE control elements CORESET Control Resource Set cRAN Cloud Wireless Access Network CSI Channel State Information CSI-RS Channel State Information Reference Signal CSI-RSRP Channel State Information Reference Signal - Received Power Based on Reference Signal CU Central Unit DCI Downlink Control Information DM-RS (or DMRS) demodulation reference signal DU Distributed Unit eNB (or eNodeB) Evolved Node B (e.g., LTE base station) EN-DC E-UTRA-NR Dual Connectivity The en-gNB or En-gNB is a node that provides NR user plane and control plane protocol termination to the UE and acts as an auxiliary node in the EN-DC. E-UTRA, or Evolved Universal Terrestrial Radio Access, is also known as LTE radio access technology. FRS Frequency Range 2 gNB (or gNodeB) is a base station used for 5G / NR, specifically a node that provides NR user plane and control plane protocol termination to the UE and is connected to the 5GC via the NG interface. HARQ Hybrid Automatic Repeat Request I / F interface L1 Floor 1 LTE Long Term Evolution MAC Media Access Control MAC-CE Media Access Control Element MIMO (Multiple Input Multiple Output) MME (Mobility Management Entity) M-TRP Multiple Sender and Receiver Point ng or NG, next generation ng-eNB or NG-eNB, the next generation of eNB NR New Wireless N / W or NW network NZP CSI-RS Non-zero Power Channel State Information Reference Signal O-RAN Open Radio Access Network PBCH (Physical Broadcast Channel) PCID Main Cell ID PDCCH (Physical Downlink Control Channel) PDCP (Packet Data Convergence Protocol) PDSCH (Physical Downlink Shared Channel) PHY physical layer PUCCH (Physical Uplink Control Channel) PUSCH Physical Uplink Shared Channel QCL Quasi-co-located RAN (Radio Access Network) RF (Radio Frequency) RLC Wireless Link Control RLM Wireless Link Monitoring RRC (Radio Resource Control) RRH Remote Wireless Head RRM Wireless Resource Management RS reference signal RU wireless unit Rx receiver SDAP Service Data Adaptation Protocol sDCI (or s-DCI) Single downlink control information SFN single-frequency network SGW Service Gateway SMF Session Management Function SR scheduling request SRS Detection Reference Signal SS synchronization signal SSB Synchronization Signal Block TCI Transport Configuration Indicator TRP Transmitter / Receiver Point TRS Tracking Reference Signal Tx transmitter UE (User Equipment) (e.g., wireless equipment, typically mobile equipment) UPF User Plane Functions VNR Virtualization Network Functions WI work items

[0026] Go to Figure 1 The figure illustrates a block diagram of one possible, non-limiting example in which practical examples can be implemented. It shows a user equipment (UE) 110, a radio access network (RAN) node 170, and (multiple) network elements 190. Figure 1In the example, User Equipment (UE) 110 wirelessly communicates with Wireless Network 100. The UE is a wireless device that can access Wireless Network 100. UE 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected via one or more buses 127. Each of the one or more transceivers 130 includes a receiver Rx 132 and a transmitter Tx 133. The one or more buses 127 may be an address bus, a data bus, or a control bus, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optic cable, or other optical communication device. "Circuit" may include dedicated hardware or hardware associated with software that can be executed thereon. The one or more transceivers 130 are connected to one or more antennas 128. The one or more memories 125 include computer program code 123. UE 110 includes a module 140, which includes one or both of portions 140-1 and / or 140-2, and may be implemented in many ways. Module 140 may be implemented in hardware as module 140-1, such as as part of one or more processors 120. Module 140-1 may also be implemented as an integrated circuit or via other hardware, such as a programmable gate array. In another example, module 140 may be implemented as module 140-2, which is implemented as computer program code 123 and executed by one or more processors 120. For example, one or more memories 125 and computer program code 123 may be configured to utilize one or more processors 120 to cause user equipment 110 to perform one or more operations as described herein. UE 110 communicates with RAN node 170 via radio link 111.

[0027] In this example, RAN node 170 is a base station that provides access to wireless network 100 by wireless devices such as UE 110. For example, RAN node 170 can be a base station for 5G, also known as New Radio (NR). In 5G, RAN node 170 can be an NG-RAN node, which is defined as a gNB or ng-eNB. A gNB is a node that provides NR user plane and control plane protocol termination to the UE and is connected to the 5GC (such as, for example, multiple network elements 190) via an NG interface. An ng-eNB is a node that provides E-UTRA user plane and control plane protocol termination to the UE and is connected to the 5GC via an NG interface. An NG-RAN node can include multiple gNBs, which can also include a central unit (CU) (gNB-CU) 196 and one or more distributed units (DUs) (gNB-DU), where DU 195 is shown. Note that a DU can include or be coupled to a radio unit (RU) and control that RU. A gNB-CU is a logical node that hosts the RRC, SDAP, and PDCP protocols of a gNB or controls the RRC and PDCP protocols of an en-gNB for the operation of one or more gNB-DUs. The gNB-CU terminates the F1 interface connected to the gNB-DU. The F1 interface is shown as reference numeral 198, but reference numeral 198 also indicates a link between a remote element of RAN node 170 and a central element of RAN node 170, such as the link between gNB-CU 196 and gNB-DU 195. A gNB-DU is a logical node that hosts the RLC, MAC, and PHY layers of a gNB or en-gNB, and its operation is partially controlled by the gNB-CU. One gNB-CU supports one or more cells. A cell is supported by only one gNB-DU. The gNB-DU terminates the F1 interface 198 connected to the gNB-CU. Please note that DU195 is considered to include transceiver 160, for example as part of an RU, but some examples may have transceiver 160 as part of a separate RU, for example, under the control of DU 195 and connected to DU 195. RAN node 170 may also be an eNB (evolved NodeB) base station for LTE (Long Term Evolution), or any other suitable base station, access point, access node, or node.

[0028] RAN node 170 includes one or more processors 152, one or more memories 155, one or more network interfaces (N / WI / F) 161, and one or more transceivers 160 interconnected via one or more buses 157. Each of the one or more transceivers 160 includes a receiver Rx 162 and a transmitter Tx 163. The one or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153. CU 196 may include one or more processors 152, memories 155, and network interfaces 161. Note that DU 195 may also contain its own memories / multiple memories and processors, and / or other hardware, but these are not shown.

[0029] RAN node 170 includes module 150, which comprises one or both of portions 150-1 and / or 150-2, and can be implemented in a variety of ways. Module 150 can be implemented in hardware as module 150-1, such as being implemented as part of one or more processors 152. Module 150-1 can also be implemented as an integrated circuit or through other hardware such as a programmable gate array. In another example, module 150 can be implemented as module 150-2, which is implemented as computer program code 153 and executed by one or more processors 152. For example, one or more memories 155 and computer program code 153 are configured to utilize one or more processors 152 to cause RAN node 170 to perform one or more of the operations described herein. Note that the functionality of module 150 can be distributed, such as distributed between DU 195 and CU 196, or implemented only in DU 195.

[0030] One or more network interfaces 161 communicate over a network, such as via links 176 and 131. Two or more gNBs 170 may communicate using, for example, link 176. Link 176 may be wired, wireless, or a combination of both, and may implement, for example, an Xn interface for 5G, an X2 interface for LTE, or other suitable interfaces for other standards.

[0031] One or more buses 157 may be address buses, data buses, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, optical fiber or other optical communication equipment, wireless channels, etc. For example, one or more transceivers 160 may be implemented as a Remote Radio Header (RRH) 195 for LTE or a Distributed Unit (DU) 195 for a gNB implementation for 5G, wherein other elements of the RAN node 170 may be physically located in different locations from the RRH / DU, and one or more buses 157 may be partially implemented as, for example, fiber optic cables or other suitable network connections to connect other elements of the RAN node 170 (e.g., Central Unit (CU), gNB-CU) to the RRH / DU 195. Reference numeral 198 also indicates those suitable network links(s).

[0032] It is important to note that the descriptions in this document refer to the functions performed by a "cell," but it should be clear that the equipment forming the cell will perform these functions. A cell constitutes part of a base station. That is, each base station can have multiple cells. For example, for a single carrier frequency and associated bandwidth, there can be three cells, each covering one-third of a 360-degree area, making the coverage area of ​​a single base station approximately elliptical or circular. Furthermore, each cell can correspond to a single carrier, while a base station can use multiple carriers. Therefore, if there are three 120-degree cells per carrier and two carriers per base station, the base station has a total of six cells.

[0033] Wireless network 100 may include one or more network elements 190, which may include core network functions and provide connectivity to another network (such as a telephone network and / or a data communication network (e.g., the Internet)) via one or more links 181. Such core network functions for 5G may include access and mobility management functions (multiple AMFs) and / or user plane functions (multiple UPFs) and / or session management functions (multiple SMFs). Such core network functions for LTE may include MME (Mobility Management Entity) / SGW (Serving Gateway) functions. These are merely illustrative functions that the network elements 190 may support, and it should be noted that both 5G and LTE functions may be supported. RAN node 170 is coupled to network element 190 via link 131. Link 131 may be implemented as, for example, an NG interface for 5G, an S1 interface for LTE, or other suitable interfaces for other standards. Network element 190 includes one or more processors 175 interconnected via one or more buses 185, one or more memories 171, and one or more network interfaces (N / WI / F) 180. The one or more memories 171 include computer program code 173. The one or more memories 171 and the computer program code 173 are configured to cause network element 190 to perform one or more operations using the one or more processors 175.

[0034] Wireless network 100 can implement network virtualization, which is the process of combining hardware and software network resources and network functions into a single software-based management entity (i.e., a virtual network). Network virtualization involves platform virtualization, often combined with resource virtualization. Network virtualization is categorized as either external, which combines multiple networks or parts of networks into virtual units, or internal, which provides network-like functionality to software containers on a single system. For example, a network can be deployed in a telecommunications cloud, where Virtualized Network Functions (VNFs) run on, for example, data center servers. For instance, network core functions and / or (multiple) wireless access networks (e.g., CloudRAN, O-RAN, edge cloud) can be virtualized. Note that the virtualized entities resulting from network virtualization are still implemented to some extent using hardware (such as processors 152 or 175 and memories 155 and 171), and such virtualized entities also produce technical effects.

[0035] It may also be noted that the operation of the example embodiments of this disclosure may be performed by multiple cooperating devices (e.g., cRAN).

[0036] Computer-readable storage devices 125, 155, and 171 can be of any type suitable for the local technical environment and can be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic storage devices and systems, optical storage devices and systems, fixed memory, and removable memory. Computer-readable storage devices 125, 155, and 171 can be components for performing storage functions. Processors 120, 152, and 175 can be of any type suitable for the local technical environment and, as non-limiting examples, can include one or more of general-purpose computers, special-purpose computers, microprocessors, digital signal processors (DSPs), and processors based on multi-core processor architectures. Processors 120, 152, and 175 can be components for performing functions such as controlling UE 110, RAN node 170, and other functions as described herein.

[0037] In general, various example embodiments of user equipment 110 may include, but are not limited to: cellular phones with wireless communication capabilities (such as smartphones, tablets, personal digital assistants (PDAs)), portable computers with wireless communication capabilities, image capture devices with wireless communication capabilities (such as digital cameras), gaming devices with wireless communication capabilities, music storage and playback devices with wireless communication capabilities, internet devices that allow wireless internet access and browsing, tablets with wireless communication capabilities, and portable units or terminals that include a combination of such functions.

[0038] A suitable, but not limiting, technical context has thus been introduced for the exemplary embodiments of this disclosure, and the exemplary embodiments will now be described in more detail.

[0039] The features described herein typically involve the use of multiple transmit / receive points (M-TRPs). An NR cell may include one or more TRPs. TRPs within the same cell have cell-specific common synchronization (SS) and / or physical broadcast channel (PBCH) blocks. In multiple transmit / receive point (multiple TRP) operation, the serving cell can schedule UEs from two TRPs, thereby providing better coverage, reliability, and / or data rates for the Physical Downlink Shared Channel (PDSCH), Physical Downlink Control Channel (PDCCH), Physical Uplink Shared Channel (PUSCH), and / or Physical Uplink Control Channel (PUCCH).

[0040] There are two distinct operating modes for scheduling multi-TRP PDSCH transmissions: single DCI (sDCI) and multi-DCI. For both modes, uplink and downlink operations can be controlled by the physical and MAC layers within a configuration provided by the Radio Resource Control (RRC) layer. In single-DCI mode, only one TRP is responsible for transmitting control data (i.e., PDCCH) to the UE. Therefore, the UE is scheduled by the same PDCCH containing DCIs for both TRPs. In contrast, in multi-DCI mode, two TRPs are responsible for transmitting control data to the UE. Therefore, the UE is scheduled by independent DCIs from each TRP.

[0041] The features described in this article often involve beam management. The 5G NR frequency range 2 bands defined by 3GPP have enormous bandwidth, sufficient for 5G NR usage scenarios requiring higher data rates. However, these bands also experience challenging radio propagation conditions, such as high path loss, absorption and penetration loss from the environment, etc. To overcome these challenges, beam management procedures have been defined in 3GPP.

[0042] Beam management is a set of procedures used to help a UE configure its receive (Rx) and transmit (Tx) beams for downlink and uplink transmissions, respectively. NR supports a hierarchical beam-based approach, where the synchronization signal block (SSB) beam is the root beam, such as... Figure 2 As shown in the example of the level 1 beam hierarchy: SS / PBCH block “beam” (210), SSB #1, SSB #m, and SSB #n partially overlap each other. In the example of the level 2-n beam hierarchy: CSI-RS “beam” (220), SSB #m, and SSB #n partially overlap each other, and SSB #n includes CSI-RS #0 (associated with SSB #n), CSI-RS #1 (associated with SSB #n), CSI-RS #2 (associated with SSB #n), and CSI-RS #3 (associated with SSB #n).

[0043] The features described herein typically involve Transport Configuration Indicator (TCI) status. Quasi-Co-location (QCL) frameworks are used for beam indication. The beam indication information provided by the gNB is used to configure the UE regarding which gNB transmit (Tx) beam should be used for the downlink (DL) (i.e., allowing the UE to select the appropriate spatial receive (Rx) setting) and which Rx beam should be used for the uplink (UL) (i.e., ensuring the UE's Tx points to the correct RX beam at the gNB).

[0044] Each TCI state contains parameters for configuring quasi-co-location relationships between one or two downlink reference signals (RS) and multiple demodulation reference signal (DM-RS) ports of the PDSCH, multiple DM-RS ports of the PDCCH, or multiple channel state information reference signal (CSI-RS) ports of the CSI-RS resources.

[0045] The quasi-co-address type corresponding to each DL RS is given by the higher-level parameter qcl-Type in QCL-Info, and can take one of the following values: QCL Type A: Doppler frequency shift, Doppler spread, average delay, delay spread QCL Type B: Doppler frequency shift, Doppler spread QCL Type C: Average Delay, Doppler Shift QCL type D: Space Rx

[0046] The primary tool for downlink beam indication is the TCI framework. In Rel-15 / 16, TCI states were defined only for the downlink, while uplink spatial relationships were used for the uplink. Rel-17 introduced a unified TCI state framework to cover both downlink and uplink. These methods will be described in more detail below.

[0047] Rel-15 / 16 TCI Framework

[0048] In Rel-15 / 16, a UE can be configured to have up to 128 TCI states. The gNB configures the TCI states for the UE via RRC signaling, where each TCI state can have one or two source reference signals (RS), which provide QCL parameters for the target RS; each TCI state can only have one RS providing QCL type D.

[0049] A DL TCI chain consists of an SSB and one or more CSI-RS resources, and the TCI state of each reference signal includes another reference signal in the same TCI chain, wherein the SSB may be associated with the serving cell primary cell ID (PCID) or with a PCID different from the serving cell PCID.

[0050] The DMRS of PDCCH or PDSCH is quasi-co-located with the reference signal in its active TCI state and with any other reference signal quasi-co-located with the reference signal in its active TCI state based on the criteria used for DL ​​TCI chains.

[0051] Now for reference Figure 3 Examples of (multiple) QCL and TCI chains are shown.

[0052] The signaling related to the DL TCI status is as follows: - Utilize RRC to configure up to 128 TCI states for the UE. - For PDCCH: 1 TCI state is indicated by DL MAC CE. - For PDSCH: Up to 8 TCI states can be activated in the code point (active TCI state list) using DL MAC CE. Among these, 1 TCI state is indicated for PDSCH using DCI.

[0053] For Rel-15 / 16 TCI status activation / indication, RAN4 has defined the following delay requirements: - TCI state switching based on MAC CE means that the MAC CE indication used for the TCI state of PDCCH - DCI-based TCI state switching means that the DCI indication used for the TCI state of PDSCH - RRC-based TCI state switching means switching to the TCI state via RRC reconfiguration. - An update to the active TCI status list means the activation / addition of (multiple) PDSCH TCI statuses to the active TCI status list.

[0054] In a multi-TRP single-DCI scenario, a TCI state is indicated for the PDCCH of the link carrying the PDCCH. For PDSCH, a single TCI state or TCI state pair can be activated to the active TCI state list, and one of these TCI states or TCI state pairs can utilize the DCI indication. RAN4 is currently using Rel-15 / 16 TCI states as a benchmark to study latency requirements for multi-TRP scenarios.

[0055] Unified TCI State Framework

[0056] The unified TCI state framework is defined by 3GPP in Rel-17. In Rel-15 / 16, TCI states were configured only for the downlink, while uplink spatial relationships encompassed beam indication for the uplink. Using the unified TCI state concept, TCI states are configured for both downlink and uplink. The configuration is either joint, where the same TCI state covers both UL and DL; or separate, where separate TCI states exist for DL ​​and UL.

[0057] The unified TCI state framework uses the concept of a common TCI state, where only one common TCI / indicating TCI state at a time provides spatial assumptions for the signal set and channels (e.g., PDCCH, PDSCH, PUCCH, PUSCH, CSI-RS, SRS).

[0058] Assigning a unified TCI status is done using the following steps: - RRC-based configuration with up to 128 TCI states. - MAC-CE-based activation in up to 16 TCI states to 8 code points. - A single combined TCI status or a pair of TCI statuses based on DCI, representing DL and UL TCI statuses.

[0059] RAN4 has defined latency requirements for the following: DL and UL TCI state transitions based on MAC CE; DL and UL TCI state transitions based on DCI; and updates to the active DL and UL TCI state lists. RAN4 agrees to use Rel-15 / 16 TCI states for multiple Rx features, but future releases are also expected to cover unified TCI states. The principles used in single DCI scenarios can be expected to be similar to the Rel-15 / 16 TCI state management principles.

[0060] The features described herein typically relate to link quality monitoring in single DCI mode. Radio link monitoring (RLM) is performed on the PDCCH. In s-DCI mode, only one link has a configured PDCCH; in other words, RLM in single DCI reception applies only to the link with the PDCCH. Asynchrony indication, synchronization indication, and radio link failure are all based on the RLM-RS received on this anchor link (i.e., implicitly based on the RS with TCI status indication for the PDCCH). There is no RLM on the other link that only has a PDSCH.

[0061] Beam Failure Detection (BFD) and Candidate Beam Detection (CBD) are performed on the PDCCH. In s-DCI mode, only one link has a configured PDCCH; in other words, BFD / CBD in single DCI reception only applies to links with a PDCCH, and therefore, this is similar to a single TRP scenario. There is no BFD / CBD on links with only a PDSCH (i.e., the RS associated with PDSCH reception is not monitored for beam failure detection). Now refer to... Figure 4This example illustrates how RLM and BFD / CBD in a single DCI reception are only applicable to links with PDCCH. In this example, TRP1 (410) provides PDSCH (420) and PDCCH (430) to UE (450), while TRP2 (460) provides PDSCH (470) to UE (450).

[0062] Please note that R4-2307348 provides a discussion of RLM and BFD / CBD for NR FR2 multi-Rx chain DL reception. Please note that R4-2304133 provides a discussion of RLM and BFD / CBD for NR FR2 multi-Rx chain DL reception. Please note that R4-2305190 describes UE-initiated TCI state handover. Refer to [link / reference] now. Figure 5 An example of a TCI state transition initiated by a UE is shown, which is described as follows: "...UE-initiated beam selection / activation is an alternative to reducing beam activation latency. Based on beam measurements, the UE can select one (i.e., beam selection) or more (i.e., beam activation) TCI states as active and report them to the network. Since the (multiple) TCI states are selected / activated by the UE, the UE is responsible for remembering the QCL attributes of the (multiple) DL RSs associated with the selected (multiple) TCI states. Therefore, measurements in the report are no longer needed. Once the UE receives the network's response to the report, DL reception can be performed immediately using the selected / activated TCI states. Because UE-initiated beam activation / deactivation combines beam reporting and beam activation into one step, latency can be significantly reduced..."

[0063] In a single DCI scenario, the network can configure the PDCCH to be sent from either of the two TRPs. Ideally, the PDCCH can be assumed to be sent from the TRP with the better radio link conditions.

[0064] The network can use available information to determine on which link to configure the PDCCH. No specific method is specified for how the network selects the PDCCH link. The UE possesses additional information on its side, such as asynchronous / synchronous indications and beam fault indications, which the network cannot access.

[0065] In a single DCI scenario, since radio link monitoring and beam fault detection only apply to links configured with PDCCH, the network has limited knowledge of the radio link conditions of links configured with only PDSCH. It is possible that the radio link conditions of a link with PDCCH may be worse than those of a link with only PDSCH, but the network cannot perceive this through RLM and BFD procedures.

[0066] The technical effect of the example embodiments of this disclosure is that, in a multi-TRP scenario using the sDCI DL scheduling mode, it ensures that the PDCCH is scheduled on the optimal TRP link in a timely manner when radio conditions are changing with the mobility of the FR2 UE.

[0067] In a single-DCI, multi-TRP scenario, the UE may be scheduled for PDSCH on two links, but PDCCH may only be scheduled on one of the TRP links. The UE can assess / determine that the downlink radio conditions on the link with only PDSCH are better for scheduling PDCCH than the conditions on the link currently scheduling PDCCH. However, the network may not be immediately aware of this condition. Example embodiments of this disclosure can provide signaling and / or reporting mechanisms in such scenarios. The technical effect of example embodiments of this disclosure can be to mitigate such scenarios. The technical effect of example embodiments of this disclosure can be to enable the network to gain insight into the above-described scenario and allow optimized PDCCH scheduling between the two TRPs.

[0068] In an example embodiment, the UE can trigger a newly defined PDCCH link switching signal, which can have the technical effect of enabling the network to respond quickly to the degradation of radio conditions on the primary TRP link that schedules the PDCCH.

[0069] In an example embodiment, a new PDCCH link switching signaling from the UE can notify the network that the UE preferably switches the PDCCH from the TRP link that currently schedules it to another TRP link that only schedules the PDSCH, for example, when certain thresholds / conditions (e.g., radio link and beam quality assessments or L1 or L3 measurements determined by the UE) are exceeded / met.

[0070] In an example embodiment, if the network accepts the UE's request for PDCCH link handover, the network can (via new signaling, such as DCI) indicate to the UE its confirmation of the PDCCH link handover. In an example embodiment, a PDCCH handover delay can be defined, which can have the technical effect of providing the NW with information about when to send a newly requested PDCCH to the UE.

[0071] Alternatively, in the example implementation, an explicit TCI state switching command / acceptance of a handover from the network may not be required. The PDCCH can be unconditionally switched to another TCI state used by the UE in the DL, for example, based on a UE request. In other words, acceptance of the handover may only be implied. In the example implementation, a PDCCH handover delay can be defined, which can have the technical effect of providing the NW with information about when to send a newly requested PDCCH to the UE.

[0072] In this disclosure, a "PDCCH+PDSCH link" can refer to a link between the UE and TRP1, in which both PDSCH and PDCCH are configured. In this disclosure, a "PDSCH-only link" can refer to a link between the UE and TRP2, in which only PDSCH is configured.

[0073] In an example embodiment, the UE may instruct the UE to initiate a handover of the PDCCH link.

[0074] In an example embodiment, a UE PDCCH link handover indicator can be defined. In an example embodiment, the UE can be configured with a new link handover indicator for sDCI mTRP operation configuration. The UE can be configured to provide the network with an indication that it prefers to switch the current PDCCH from a PDCCH+PDSCH link to a PDSCH-only link (or vice versa). In an example embodiment, the UE can provide this indication in L1 signaling, such as a scheduling request (SR) configured for such an indication. In an example embodiment, the UE can include this indication as part of an L1-RSRP report. In an example embodiment, the UE can also / alternatively include this indication in another message, such as UE auxiliary information.

[0075] In an example embodiment, the UE can be configured to indicate a link switch when it determines that a PDSCH-only link will provide better / more robust channel conditions for control of reception than a PDCCH+PDSCH link. This can be determined based on one or more conditions, thresholds, or metrics. As an example, the UE can be configured with RSRP-based conditions, which are based on L1 / L3 measurements on each link.

[0076] In an example embodiment, the UE can be configured to indicate link switching when it determines that the quality of the current PDCCH+PDSCH link is below a threshold, which can be a UE-based threshold.

[0077] In the example embodiment, the UE can receive a network indication for switching PDCCH links. In the example embodiment, when the UE has been configured to perform link switching, it can receive a network indication that commands link switching.

[0078] In the example embodiment, when a link switching command is detected by the NW, the UE can expect / be configured to monitor the PDCCH on the PDSCH-only link on the TCI state previously indicated for PDSCH reception (i.e., the UE can assume that the previous PDSCH TCI state is to be used as the TCI state for the indication of PDCCH).

[0079] In the example embodiment, when a link switching command is detected by the NW, the UE can expect / be configured to monitor the PDSCH on the PDCCH-PDSCH link on the TCI state previously indicated for PDCCH reception (i.e., the UE can assume that the previous PDCCH TCI state is to be used as the TCI state for PDSCH indication).

[0080] In an example embodiment, in an sDCI-specific implementation, the UE may assume that the second indicated TCI state is now configured as the first indicated TCI state, and vice versa. For example, the first indicated TCI state may be the TCI state that instructs the UE to monitor the PDCCH and receive the PDSCH on that indicated TCI state, while the second indicated TCI state may be used for PDSCH reception.

[0081] Now for reference Figure 6 This shows an example of the TCI state at the PDCCH link switch. Figure 6 In the example, assuming on the PDCCH-PDSCH link, for TRP1 (610), the same TCI state is used for both PDCCH (620) and PDSCH (630), i.e., TCI#0. This could mean utilizing: a unified TCI state, in which case a common TCI state is used for both PDSCH and PDCCH; or a Rel-15 / 16 TCI state, where the TCI states for PDCCH and PDSCH are indicated separately, but the same actual TCI state can be used for both. For TRP2 (640), TCI#1 (650) can be used for PDSCH. After the switch (660), for TRP1 (610), TCI#0 can be used for PDSCH (670); while for TRP2 (640), TCI#1 can be used for both PDCCH (680) and PDSCH (690). This could mean that TCI#1 is used as the unified TCI state.

[0082] In an example embodiment, after providing an indication to the network, the UE may expect the NW to respond using a new DCI-based indication, such as one indicating a link handover procedure. The DCI indication may be included in the current DCI format or a new format. For example, the indication could be a 1-bit (ACK) indication. In an example embodiment, after providing this indication to the network, the UE may expect the NW to trigger a link handover using, for example, a MAC CE.

[0083] In the example embodiment, the link handover indication configuration can be provided using RRC configuration. In the example embodiment, the RRC configuration can indicate whether a PDDCH link handover is expected for the UE due to link quality degradation. In the example embodiment, the link handover indication can be dynamically configured.

[0084] In an example embodiment, the link switching indication may be an explicit indication of link switching based on the MAC-CE indication that triggered the link switching.

[0085] Now for reference Figure 7 This illustrates a UE and network signaling for implementing PDCCH link handover according to an example embodiment of this disclosure. Figure 7 In the example, TRP1 and TRP2 can belong to the same network node. Figure 7 In the example, it is assumed that in addition to the PDCCH, the uplink is also configured on TRP1, so all UE signaling toward the network will travel to TRP1.

[0086] At 705, the UE can be in a single DCI multi-TRP mode. The UE can be scheduled with PDCCH and PDSCH from TRP1. The UE can also be scheduled with PDSCH from TRP2. At 710, the UE can receive PDSCH from TRP2. At 715, the UE can signal its ability to initiate PDCCH link handover indications. This UE capability can be included in pdcch-Switching-in-sDCI. At 720, the network can enable UE-initiated PDCCH link handover indications. The PDCCH link handover indication can be sent to the UE from TRP1 via an RRCReconfiguration message. This message can include OtherConfig-v1800 and / or pdcch-Switching-in-sDCI=enabled. At 725, the UE can, for example, evaluate the link quality of the two links based on the L1 / L3 RSRP and conclude that, for PDCCH reception, the quality of the PDSCH-only link from TRP2 will be better than the current PDCCH+PDSCH link from TRP1.

[0087] At points 735 / 745, the UE can indicate to the network that it will preferably switch the PDCCH to another link. Figure 7 In the example, options A (730) and B (740) are alternatives to each other. In option A (730), at 735, the indication can be sent in the UE assistance information. The UE assistance information may include pdcch-Switching-in-sDCI (a request to switch the PDCCH to TRP2). In option B (740), at 745, the indication can be included in the L1 measurement report. The L1 measurement report may include pdcch-Switching-in-sDCI (a request to switch the PDCCH to TRP2).

[0088] At position 750, the network can accept a UE's request to switch the PDCCH to another link (i.e., from TRP1 to TRP2). At positions 760 / 770 / 780, the network can explicitly acknowledge the PDCCH link switch to the UE. Figure 7 In the example, options 1 (755), 2 (765), and 3 (775) are alternatives to each other. In option 1 (755), at 760, the PDCCH link switch can be indicated by a DL MAC-CE containing an indication field confirming the link switch. The DL MAC-CE can include an indication to switch the PDCCH to TRP2. In option 2 (765), at 770, the PDCCH link switch can be indicated by a DCI containing an indication field confirming the switch. The DCI can include an indication to switch the PDCCH to TRP2. In option 3 (775), at 780, the PDCCH link switch can be indicated by an RRC reconfiguration. The RRC reconfiguration can include an indication to switch the PDCCH to TRP2.

[0089] At point 785, a handover of the PDCCH link from TRP1 to TRP2 can be performed, including the TCI state handover steps disclosed above. At point 790, the UE can be scheduled with PDSCH from TRP1. At point 795, the UE can be scheduled with both PDCCH and PDSCH from TRP2. Therefore, the PDCCH link has been switched.

[0090] Now for reference Figure 8 This illustrates a UE and network signaling for implementing PDCCH link handover according to an alternative example embodiment of this disclosure. Figure 8 In the example, TRP1 and TRP2 can belong to the same network node.

[0091] At 805, the UE can be in a single DCI multi-TRP mode. The UE can be scheduled with PDCCH and PDSCH from TRP1. At 810, the UE can be scheduled with PDSCH from TRP2. At 815, the UE can signal its ability to initiate a PDCCH link handover indication. The UE capability can be sent to TRP1 via the pdcch-Switching-in-sDCI signal. At 820, the network can enable the UE-initiated PDCCH link handover indication. This can be indicated via an RRCReconfiguration message, which may include OtherConfig-v1800 and / or pdcch-Switching-in-sDCI=enabled. At 825, the UE can evaluate the link quality of the two links based on, for example, L1 / L3 RSRP, and conclude that for PDCCH reception, the PDSCH-only link from TRP2 will be better than the current PDCCH+PDSCH link from TRP1.

[0092] At points 835 / 845, the UE can indicate to the network that it will preferably switch the PDCCH to another link. Figure 8 In the example, options A (830) and B (840) are alternatives to each other. In option A (830), at 835, the indication can be sent in the UE assistance information. The UE assistance information may include pdcch-Switching-in-sDCI (a request to switch the PDCCH to TRP2). In option B (840), at 845, the indication can be included in the L1 measurement report. The L1 measurement report may include pdcch-Switching-in-sDCI (a request to switch the PDCCH to TRP2).

[0093] At 850, the UE can receive an L1-HARQ acknowledgment for the message in option A (830) or option B (840). This could be an implicit indication that the network has acknowledged the PDCCH link switch. At 855, the PDCCH link switch from TRP1 to TRP2 can be performed, including the TCI state switch-related steps disclosed above. At 860, the UE can be scheduled with PDSCH from TRP1. At 865, the UE can be scheduled with both PDCCH and PDSCH from TRP2. Therefore, the PDCCH link has been switched.

[0094] In the example implementation, predefined delay requirements can be defined for UE-initiated PDCCH handovers. The definition of the delay may vary depending on the type of message used to indicate the handover (e.g., HARQ ACK, DCI, MAC-CE, RRC, etc.). For example, the delay can be the time from when the UE receives / decodes the handover indication message until the UE is able to receive the PDCCH from the target TRP. The delay can be defined in the RAN1 or RAN4 specifications.

[0095] For example, TCI state transition latency is currently defined in TS 38.133: "...8.10.3 TCI State Switching Delay Based on MAC-CE" If the target TCI state is known, then after receiving the PDSCH carrying the MAC-CE activation command in time slot n, the UE will be able to... The PDCCH with the target TCI state of the serving cell on which the TCI state handover occurred is received in the first time slot after the time slot length. The UE will be able to receive PDCCH with the old TCI state until the time slot ends. Up to that point. Among them, T HARQ This refers to the timing between DL data transmission and confirmation as specified in TS 38.213[3]; -T first-SSB This refers to the time between the MAC CE command being decoded by the UE and the first SSB transmission; the SSB will be either QCL-Type A or QCL-Type C to achieve the target TCI state. -T SSB-proc =2ms; - If the target TCI state is not in the list of active TCI states used for PDSCH, then TO k =1, otherwise 0. ... 8.10.4 DCI-based TCI state transition delay If the target TCI state is known, when the UE is configured with higher-layer parameters tci-PresentInDCI When the CORESET scheduling PDSCH is set to "enabled" at time slot n, the UE will be able to... n+timeDurationForQCL In the first time slot thereafter, a PDSCH containing the target TCI state of the serving cell on which a TCI state handover has occurred is received, wherein, timeDurationForQCL This is the time required for the UE to perform PDCCH reception and apply the spatial QCL information received in the DCI to the PDSCH processing, as described in TS 38.214

[26] . timeDurationForQCL The value is defined in TS38.331 [2]. The known conditions of the TCI status as defined in Clause 8.10.2 apply. ... 8.15.4 Downlink TCI State Switching Delay Based on DCI When the UE is configured with DLorJointTCIState or UL-TCIState When the higher-layer parameters (which activate the TCI state for downlink transmission via MAC CE indication of more than one code point) are received and a DCI format 1_1 / 1_2 with or without DL assignment (which provides the indicated TCI state or TCI state pair in the active TCI list for CC) is received, the UE transmits a PUCCH with HARQ-ACK information corresponding to the DCI carrying the TCI state indication…”

[0096] Therefore, we can conclude that, under traditional requirements, for PDCCH handover based on MAC CE, assuming the target TCI state is known (already used for DL ​​reception of PDSCH from TRP2), the UE will be able to... The PDCCH with the target TCI state of the serving cell on which the TCI state handover occurred is received in the first time slot thereafter. We can also conclude that, in conventional requirements, DCI-based PDCCH handover is defined only for the unified TCI framework, and no delay is defined when the UE will be able to receive PDCCH with the new / target TCI state.

[0097] According to the implementation of the new PDCCH handover requested by the UE (e.g.) Figure 7 , Figure 8 The following requirements for UE PDCCH handover can be foreseen.

[0098] For example, a new DCI command from the NW to the UE can be used to accept a UE-requested PDCCH handover from TRP1 to TRP2. The UE can receive a PDCCH with a PDCCH state handover acknowledgment / indication in time slot n. In one option, the UE can receive the PDCCH of the target TCI state of the serving cell on which the TCI state handover occurs at the first time slot (i.e., after time slot n+X ms), where X ms can be the time required for the UE to perform PDCCH reception and switch the PDCCH to the new TCI state (e.g., switch to a new TRP, UE panel, etc.). In another option, the UE can send HARQ-ACK information corresponding to the DCI carrying the requested PDCCH state handover acknowledgment / indication (e.g., if DCI format 1_1 / 1_2 is used). In this case, a specific handover delay can be not defined because it is assumed that the UE is ready to receive the new PDCCH at the time of HARQ-ACK transmission or at its expected reception on the NW side.

[0099] For example, explicit NW indication / acknowledgment for PDCCH handover can be omitted (i.e., PDCCH handover can be based solely on UE indication, e.g., because the TCI state has already been used for PDSCH). Therefore, the following UE requirements can be introduced. For example, after receiving a PDCCH handover request from the UE, the NW can send a HARQ-ACK in response. The UE can receive the HARQ-ACK for the PDCCH handover request in time slot n. The UE can be able to receive the PDCCH with the target TCI state of the serving cell on which the TCI state handover occurred at the first time slot (i.e., after time slot n + Y ms), where Y ms can be the time required for the UE to perform PDCCH / HARQ-ACK reception and handover the PDCCH to the new TCI state (e.g., handover to a new TRP, UE panel, etc.).

[0100] The exemplary embodiments of this disclosure may relate to new signaling aspects that may be covered in the RAN2 specification. When considering RAN2 aspects, this specification may include support for a gNB that indicates to the UE its ability to transmit UE-initiated PDCCH link handovers. Reference now... Figure 9 This section illustrates an example of new parameters for UE capabilities used for PDCCH link handover in sDCI scenarios. At 910, the pdcch-Switching-in-sDCI element can optionally be included in the UECapabilityInformation. This element can signal the UE's capabilities for PDCCH link handover in sDCI scenarios.

[0101] The technical effect of the exemplary embodiments of this disclosure is that when the PDCCH link quality is deteriorating but the link to other TRPs remains good, it enables early and rapid PDCCH (TRP) link handover between TCI states already monitored by the network. The technical effect of the exemplary embodiments of this disclosure is that it improves beam quality monitoring in s-DCI scenarios. The technical effect of the exemplary embodiments of this disclosure is that it avoids beam failures, which can save the overhead of (multiple) radio link failure procedures and / or (multiple) beam failure recovery procedures.

[0102] Figure 10 The potential steps of example method 1000 are illustrated. Example method 1000 may include: determining the quality of a first link with a first transmission point of a network node, wherein the first link is configured to carry a physical downlink control channel, 1010; determining the quality of a second link with a second transmission point of the network node, 1020; determining to switch the physical downlink control channel from the first link to the second link, 1030; and sending a request to the network node to switch the physical downlink control channel from the first link to the second link, 1040. For example, example method 1000 may be performed using a UE.

[0103] Figure 11 The potential steps of example method 1100 are illustrated. Example method 1100 may include: receiving from a user equipment a request to switch the physical downlink control channel from a first link to a second link, wherein the first link is provided via a first transmission point and the second link is provided via a second transmission point, 1110; and sending to the user equipment an acknowledgment of the request to switch the physical downlink control channel from the first link to the second link, 1120. Example method 1100 may be performed, for example, using a network node, base station, eNB, gNB, etc.

[0104] According to one example embodiment, an apparatus may include: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: determine the quality of a first link with a first transmission point to a network node, wherein the first link may be configured to carry a physical downlink control channel; determine the quality of a second link with a second transmission point to the network node; determine to switch the physical downlink control channel from the first link to the second link; and send a request to the network node to switch the physical downlink control channel from the first link to the second link.

[0105] The first transmission point of a network node may include the first transmission and reception point of the network node, and the second transmission point of a network node may include the second transmission and reception point of the network node.

[0106] The first and second links can be configured to carry a physical downlink shared channel.

[0107] The example device can also be configured to: send an indication to a network node that supports physical downlink control channel link switching capability; and receive a configuration from a network node that enables physical downlink control channel link switching.

[0108] The example device can also be configured to monitor a second link for the physical downlink control channel.

[0109] Determining to switch the physical downlink control channel from the first link to the second link may include the example apparatus being further configured to: determine that the link quality of the second link exceeds a threshold; and in response to the link quality of the second link exceeding the threshold, determine to switch the physical downlink control channel from the first link to the second link.

[0110] Determining to switch the physical downlink control channel from the first link to the second link may include the example apparatus being further configured to: determine that the quality of the second link is higher than the quality of the first link; and in response to the quality of the second link being higher than the quality of the first link, determine to switch the physical downlink control channel from the first link to the second link.

[0111] Determining to switch the physical downlink control channel from the first link to the second link may include the example apparatus being further configured to: determine that the link quality of the first link is below a threshold; and in response to the link quality of the first link being below the threshold, determine to switch the physical downlink control channel from the first link to the second link.

[0112] A request to switch the physical downlink control channel from the first link to the second link can be sent via one of the following: user equipment auxiliary information, scheduling request, L1 reference signal received power report, L1 measurement report, or channel state information.

[0113] The example device can also be configured to receive, via a first link, an acknowledgment from a network node of a request to switch the physical downlink control channel from the first link to the second link.

[0114] The confirmation may include an indication to switch the physical downlink control channel from the first link to the second link, wherein the confirmation may be received via one of the following: a media access control element, a downlink control information indication, or a radio resource control reconfiguration message.

[0115] The example device can also be configured to determine, at least in part, the delay for switching the physical downlink control channel from the first link to the second link based on the acknowledgment.

[0116] The acknowledgment can be received via downlink control information indication, and the example device can also be configured to: send a hybrid automatic repeat request acknowledgment to a network node in response to a downlink control information indication; and prepare to receive the physical downlink control channel via a second link at either the time of transmission of the hybrid automatic repeat request acknowledgment or the expected time of reception of the hybrid automatic repeat request acknowledgment by the network node.

[0117] This confirmation may include a hybrid automatic repeat request confirmation.

[0118] The determined delay can be based at least in part on: the time of receiving acknowledgments and the time of switching the physical downlink control channel.

[0119] According to one aspect, an example method may be provided, the example method comprising: using a user equipment to determine the quality of a first link with a first transmission point to a network node, wherein the first link may be configured to carry a physical downlink control channel; determining the quality of a second link with a second transmission point to the network node; determining to switch the physical downlink control channel from the first link to the second link; and sending a request to the network node to switch the physical downlink control channel from the first link to the second link.

[0120] The first transmission point of a network node may include the first transmission and reception point of the network node, and the second transmission point of a network node may include the second transmission and reception point of the network node.

[0121] The first and second links can be configured to carry a physical downlink shared channel.

[0122] The example method may also include: sending an indication to a network node that supports the capability of physical downlink control channel link switching; and receiving a configuration from the network node that enables physical downlink control channel link switching.

[0123] This example method may also include: monitoring a second link for the physical downlink control channel.

[0124] Determining to switch the physical downlink control channel from the first link to the second link may include: determining that the link quality of the second link exceeds a threshold; and in response to the link quality of the second link exceeding the threshold, determining to switch the physical downlink control channel from the first link to the second link.

[0125] Determining to switch the physical downlink control channel from the first link to the second link may include: determining that the quality of the second link is higher than that of the first link; and in response to the fact that the quality of the second link is higher than that of the first link, determining to switch the physical downlink control channel from the first link to the second link.

[0126] Determining to switch the physical downlink control channel from the first link to the second link may include: determining that the link quality of the first link is below a threshold; and in response to the link quality of the first link being below the threshold, determining to switch the physical downlink control channel from the first link to the second link.

[0127] A request to switch the physical downlink control channel from the first link to the second link can be sent via one of the following: user equipment auxiliary information, scheduling request, L1 reference signal received power report, L1 measurement report, or channel state information.

[0128] The example method may also include: receiving, via the first link, an acknowledgment from a network node of a request to switch the physical downlink control channel from the first link to the second link.

[0129] The confirmation may include an indication to switch the physical downlink control channel from the first link to the second link, wherein the confirmation may be received via one of the following: a media access control element, a downlink control information indication, or a radio resource control reconfiguration message.

[0130] Example methods may also include: determining, at least in part, the delay for switching the physical downlink control channel from the first link to the second link based on the acknowledgment.

[0131] The acknowledgment may be received via a downlink control information indication and also includes: sending a hybrid automatic repeat request acknowledgment to a network node in response to the downlink control information indication; and preparing to receive the physical downlink control channel via a second link at one of the following times: the time of transmission of the hybrid automatic repeat request acknowledgment, or the expected time of reception of the hybrid automatic repeat request acknowledgment by the network node.

[0132] This confirmation may include a hybrid automatic repeat request confirmation.

[0133] The determined delay can be based at least in part on: the time of receiving acknowledgments and the time of switching the physical downlink control channel.

[0134] According to one example embodiment, an apparatus may include: a circuit system configured to perform the following operations: determining the quality of a first link with a first transmission point to a network node, wherein the first link may be configured to carry a physical downlink control channel; determining the quality of a second link with a second transmission point to the network node; determining to switch the physical downlink control channel from the first link to the second link; and sending a request to the network node to switch the physical downlink control channel from the first link to the second link.

[0135] According to one example embodiment, an apparatus may include: a processing circuitry system; and a memory circuitry system including computer program code, the memory circuitry system and the computer program code being configured to utilize the processing circuitry system to enable the apparatus to: determine the quality of a first link with a first transmission point to a network node, wherein the first link may be configured to carry a physical downlink control channel; determine the quality of a second link with a second transmission point to the network node; determine to switch the physical downlink control channel from the first link to the second link; and send a request to the network node to switch the physical downlink control channel from the first link to the second link.

[0136] As used herein, the term "circuit system" may refer to one or more or all of the following: (a) a hardware circuit implementation only (such as an implementation of an analog and / or digital circuit system only); (b) a combination of hardware circuitry and software, such as (where applicable): (i) a combination of (multiple) analog and / or digital hardware circuitry and software / firmware, and (ii) any portion of (multiple) hardware processors (including (multiple) digital signal processors), software, and (multiple) memories having software, which together operate to enable a device (such as a mobile phone or a server) to perform various functions; and (c) (multiple) hardware circuitry and / or (multiple) processors (such as (multiple) microprocessors or portions thereof) that require software (e.g., firmware) to function, but may be absent if not required to function. This definition of circuit system applies to the term in this application and in all uses thereof, including in any claim. As another example, as used herein, the term circuit system also encompasses a hardware circuitry or processor (or multiple processors) or a portion thereof and its accompanying software and / or firmware implementation. For example, and if applicable to a particular claim element, the term circuit system also covers baseband integrated circuits or processor integrated circuits in mobile devices, or similar integrated circuits in servers, cellular network devices, or other computing or network devices.

[0137] According to one example embodiment, an apparatus may include components for: determining the quality of a first link with a first transmission point to a network node, wherein the first link may be configured to carry a physical downlink control channel; determining the quality of a second link with a second transmission point to the network node; determining to switch the physical downlink control channel from the first link to the second link; and sending a request to the network node to switch the physical downlink control channel from the first link to the second link.

[0138] The first transmission point of a network node may include the first transmission and reception point of the network node, and the second transmission point of a network node may include the second transmission and reception point of the network node.

[0139] The first and second links can be configured to carry a physical downlink shared channel.

[0140] This component can also be configured to: send an indication to a network node that supports the capability of physical downlink control channel link switching; and receive a configuration from a network node that enables physical downlink control channel link switching.

[0141] This component can also be configured to: monitor the second link for the physical downlink control channel.

[0142] The components used to determine whether to switch the physical downlink control channel from the first link to the second link may include components configured to: determine that the link quality of the second link exceeds a threshold; and, in response to the link quality of the second link exceeding the threshold, determine whether to switch the physical downlink control channel from the first link to the second link.

[0143] The components used to determine whether to switch the physical downlink control channel from the first link to the second link may include components configured to: determine that the quality of the second link is higher than that of the first link; and determine whether to switch the physical downlink control channel from the first link to the second link in response to the fact that the quality of the second link is higher than that of the first link.

[0144] The components used to determine whether to switch the physical downlink control channel from the first link to the second link may include components configured to: determine that the link quality of the first link is below a threshold; and, in response to the link quality of the first link being below the threshold, determine whether to switch the physical downlink control channel from the first link to the second link.

[0145] A request to switch the physical downlink control channel from the first link to the second link can be sent via one of the following: user equipment auxiliary information, scheduling request, L1 reference signal received power report, L1 measurement report, or channel state information.

[0146] This component can also be configured to: receive, via a first link, confirmation from a network node of a request to switch the physical downlink control channel from the first link to the second link.

[0147] The confirmation may include an indication to switch the physical downlink control channel from the first link to the second link, wherein the confirmation may be received via one of the following: a media access control element, a downlink control information indication, or a radio resource control reconfiguration message.

[0148] The component can also be configured to: determine, at least in part, the delay for switching the physical downlink control channel from the first link to the second link based on the acknowledgment.

[0149] The acknowledgment can be received via a downlink control information indication, wherein the component can also be configured to: send a hybrid automatic repeat request acknowledgment to the network node in response to the downlink control information indication; and prepare to receive the physical downlink control channel via the second link at one of the following times: the transmission time of the hybrid automatic repeat request acknowledgment, or the expected time for the network node to receive the hybrid automatic repeat request acknowledgment.

[0150] This confirmation may include a hybrid automatic repeat request confirmation.

[0151] The determined delay can be based at least in part on: the time of receiving acknowledgments and the time of switching the physical downlink control channel.

[0152] A processor, memory, and / or an example algorithm (which may be encoded as instructions, a program, or code) may be provided as an example component for providing or causing the execution of an operation.

[0153] According to one example embodiment, a non-transitory computer-readable medium includes instructions stored thereon that, when executed using at least one processor, cause the at least one processor to: determine the quality of a first link with a first transmission point to a network node, wherein the first link may be configured to carry a physical downlink control channel; determine the quality of a second link with a second transmission point to the network node; determine to switch the physical downlink control channel from the first link to the second link; and send a request to the network node to switch the physical downlink control channel from the first link to the second link.

[0154] According to one example embodiment, a non-transitory computer-readable medium includes program instructions stored thereon for performing the following operations: determining the quality of a first link with a first transmission point to a network node, wherein the first link may be configured to carry a physical downlink control channel; determining the quality of a second link with a second transmission point to the network node; determining to switch the physical downlink control channel from the first link to the second link; and sending a request to the network node to switch the physical downlink control channel from the first link to the second link.

[0155] According to another example embodiment, a machine-readable non-transitory program storage device may be provided, which tangibly embodies instructions executable by a machine to perform operations including: determining the quality of a first link with a first transmission point to a network node, wherein the first link may be configured to carry a physical downlink control channel; determining the quality of a second link with a second transmission point to the network node; determining to switch the physical downlink control channel from the first link to the second link; and sending a request to the network node to switch the physical downlink control channel from the first link to the second link.

[0156] According to another example embodiment, a non-transitory computer-readable medium includes instructions that, when executed by a device, cause the device to perform at least the following operations: determining the quality of a first link with a first transmission point to a network node, wherein the first link may be configured to carry a physical downlink control channel; determining the quality of a second link with a second transmission point to the network node; determining to switch the physical downlink control channel from the first link to the second link; and sending a request to the network node to switch the physical downlink control channel from the first link to the second link.

[0157] A computer-implemented system includes: at least one processor and at least one non-transitory memory storing instructions, which, when executed by the at least one processor, cause the system to at least: determine the quality of a first link with a first transmission point to a network node, wherein the first link can be configured to carry a physical downlink control channel; determine the quality of a second link with a second transmission point to the network node; determine to switch the physical downlink control channel from the first link to the second link; and send a request to the network node to switch the physical downlink control channel from the first link to the second link.

[0158] A computer-implemented system includes: components for determining the quality of a first link with a first transmission point to a network node, wherein the first link can be configured to carry a physical downlink control channel; components for determining the quality of a second link with a second transmission point to the network node; components for determining to switch the physical downlink control channel from the first link to the second link; and components for sending a request to the network node to switch the physical downlink control channel from the first link to the second link.

[0159] According to one example embodiment, an apparatus may include: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: receive from a user equipment a request to switch a physical downlink control channel from a first link to a second link, wherein the first link may be provided via a first transmission point, and wherein the second link may be provided via a second transmission point; and send to the user equipment an acknowledgment of the request to switch the physical downlink control channel from the first link to the second link.

[0160] The first transmission point may include a first transmission and receiving point, and the second transmission point may include a second transmission and receiving point.

[0161] The first and second links can be configured to carry a physical downlink shared channel.

[0162] The example device can also be configured to: receive an indication from a user equipment that supports physical downlink control channel link switching capability; and send a configuration to the user equipment to enable physical downlink control channel link switching.

[0163] A request to switch the physical downlink control channel from the first link to the second link can be received via one of the following: user equipment auxiliary information, scheduling request, L1 reference signal received power report, L1 measurement report, or channel state information.

[0164] The acknowledgment may include an indication to switch the physical downlink control channel from the first link to the second link. The acknowledgment may be sent via one of the following: a media access control element, a downlink control information indication, or a radio resource control reconfiguration message.

[0165] The acknowledgment can be sent via downlink control information indication, and the example device can also be configured to receive a hybrid automatic repeat request acknowledgment from the user equipment in response to the downlink control information indication.

[0166] This confirmation may include a hybrid automatic repeat request confirmation.

[0167] According to one aspect, an example method may be provided, comprising: using a network node, receiving from a user equipment a request to switch a physical downlink control channel from a first link to a second link, wherein the first link may be provided via a first transmission point, and wherein the second link may be provided via a second transmission point; and sending an acknowledgment to the user equipment of the request to switch the physical downlink control channel from the first link to the second link.

[0168] The first transmission point may include a first transmission and receiving point, and the second transmission point may include a second transmission and receiving point.

[0169] The first and second links can be configured to carry a physical downlink shared channel.

[0170] Example methods may also include: receiving an indication from the user equipment that supports physical downlink control channel link handover capability; and sending a configuration to the user equipment to enable physical downlink control channel link handover.

[0171] A request to switch the physical downlink control channel from the first link to the second link can be received via one of the following: user equipment auxiliary information, scheduling request, L1 reference signal received power report, L1 measurement report, or channel state information.

[0172] The confirmation may include an indication to switch the physical downlink control channel from the first link to the second link, wherein the confirmation may be sent via one of the following: a media access control element, a downlink control information indication, or a radio resource control reconfiguration message.

[0173] The acknowledgment may be sent via downlink control information indication, and the example method may also include: receiving a hybrid automatic repeat request acknowledgment from the user equipment in response to the downlink control information indication.

[0174] This confirmation may include a hybrid automatic repeat request confirmation.

[0175] According to one example embodiment, an apparatus may include: circuitry configured to perform the following operations: receiving from a user equipment a request to switch a physical downlink control channel from a first link to a second link, wherein the first link may be provided via a first transmission point, and wherein the second link may be provided via a second transmission point; and circuitry configured to perform the following operations: sending to the user equipment an acknowledgment of the request to switch the physical downlink control channel from the first link to the second link.

[0176] According to one example embodiment, an apparatus may include: a processing circuitry system; and a memory circuitry system including computer program code, the memory circuitry system and the computer program code being configured to utilize the processing circuitry system to enable the apparatus to: receive from a user equipment a request to switch a physical downlink control channel from a first link to a second link, wherein the first link may be provided via a first transmission point, and wherein the second link may be provided via a second transmission point; and send an acknowledgment to the user equipment of the request to switch the physical downlink control channel from the first link to the second link.

[0177] According to one example embodiment, an apparatus may include components for: receiving from a user equipment a request to switch a physical downlink control channel from a first link to a second link, wherein the first link may be provided via a first transmission point and the second link may be provided via a second transmission point; and sending to the user equipment an acknowledgment of the request to switch the physical downlink control channel from the first link to the second link.

[0178] The first transmission point may include a first transmission and receiving point, and the second transmission point may include a second transmission and receiving point.

[0179] The first and second links can be configured to carry a physical downlink shared channel.

[0180] This component can also be configured to: receive an indication from the user equipment that supports the physical downlink control channel link handover capability; and send a configuration to the user equipment to enable the physical downlink control channel link handover.

[0181] A request to switch the physical downlink control channel from the first link to the second link can be received via one of the following: user equipment auxiliary information, scheduling request, L1 reference signal received power report, L1 measurement report, or channel state information.

[0182] The confirmation may include an indication to switch the physical downlink control channel from the first link to the second link, wherein the confirmation may be sent via one of the following: a media access control element, a downlink control information indication, or a radio resource control reconfiguration message.

[0183] The acknowledgment can be sent via downlink control information indication, wherein the component can also be configured to: receive hybrid automatic repeat request acknowledgment from user equipment in response to downlink control information indication.

[0184] This confirmation may include a hybrid automatic repeat request confirmation.

[0185] According to one example embodiment, a non-transitory computer-readable medium includes instructions stored thereon that, when executed using at least one processor, cause the at least one processor to: receive from a user equipment a request to switch a physical downlink control channel from a first link to a second link, wherein the first link may be provided via a first transmission point, and wherein the second link may be provided via a second transmission point; and send to the user equipment an acknowledgment of the request to switch the physical downlink control channel from the first link to the second link.

[0186] According to one example embodiment, a non-transitory computer-readable medium includes program instructions stored thereon for performing at least the following operations: causing a user equipment to receive a request to switch a physical downlink control channel from a first link to a second link, wherein the first link may be provided via a first transmission point, and wherein the second link may be provided via a second transmission point; and causing an acknowledgment to be sent to the user equipment of the request to switch the physical downlink control channel from the first link to the second link.

[0187] According to another example embodiment, a machine-readable non-transitory program storage device may be provided, which tangibly embodies instructions executable by a machine to perform the following operations: causing a request to be received from a user equipment to switch a physical downlink control channel from a first link to a second link, wherein the first link may be provided via a first transmission point, and wherein the second link may be provided via a second transmission point; and causing an acknowledgment to be sent to the user equipment of the request to switch the physical downlink control channel from the first link to the second link.

[0188] According to another example embodiment, a non-transitory computer-readable medium may be provided, including instructions that, when executed by a device, cause the device to at least: receive from a user equipment a request to switch a physical downlink control channel from a first link to a second link, wherein the first link may be provided via a first transmission point, and wherein the second link may be provided via a second transmission point; and send to the user equipment an acknowledgment of the request to switch the physical downlink control channel from the first link to the second link.

[0189] A computer-implemented system includes: at least one processor and at least one non-transitory memory storing instructions that, when executed by the at least one processor, cause the system to at least: receive from a user equipment a request to switch a physical downlink control channel from a first link to a second link, wherein the first link may be provided via a first transmission point, and wherein the second link may be provided via a second transmission point; and send to the user equipment an acknowledgment of the request to switch the physical downlink control channel from the first link to the second link.

[0190] A computer-implemented system includes: components for causing a user equipment to receive a request to switch a physical downlink control channel from a first link to a second link, wherein the first link may be provided via a first transmission point, and wherein the second link may be provided via a second transmission point; and components for causing an acknowledgment to be sent to the user equipment of the request to switch the physical downlink control channel from the first link to the second link.

[0191] As used in this article, the term “non-transient” refers to a limitation on the medium itself (i.e., tangible rather than signaling), rather than a limitation on the persistence of data storage (e.g., RAM and ROM).

[0192] It should be understood that the above description is illustrative only. Those skilled in the art can devise various alternatives and modifications. For example, the features recited in the dependent claims can be combined with each other in any suitable combination(s). Furthermore, features from the different embodiments described above can be selectively combined into new embodiments. Therefore, this specification is intended to cover all alternatives, modifications, and variations falling within the scope of the appended claims.

Claims

1. A method comprising: The quality of a first link to a first transmission point of a network node is determined using a user equipment, wherein the first link is configured to carry a physical downlink control channel; Determine the quality of the second link with the second transmission point of the network node; Determine to switch the physical downlink control channel from the first link to the second link; as well as Send a request to the network node to switch the physical downlink control channel from the first link to the second link.

2. The method according to claim 1, wherein the first transmission point of the network node includes a first transmission and reception point of the network node, and wherein the second transmission point of the network node includes a second transmission and reception point of the network node.

3. The method according to claim 1 or 2, wherein the first link and the second link are configured to carry a physical downlink shared channel.

4. The method according to any one of claims 1 to 3, further comprising: Send an indication to the network node that supports the capability of physical downlink control channel link switching; as well as Receive configuration from the network node that enables the switching of the physical downlink control channel link.

5. The method according to any one of claims 1 to 4, further comprising: The second link is monitored for the physical downlink control channel.

6. The method according to any one of claims 1 to 5, wherein determining to switch the physical downlink control channel from the first link to the second link comprises: It was determined that the link quality of the second link exceeded the threshold; as well as In response to the link quality of the second link exceeding the threshold, it is determined to switch the physical downlink control channel from the first link to the second link.

7. The method according to any one of claims 1 to 5, wherein determining to switch the physical downlink control channel from the first link to the second link comprises: It is determined that the quality of the second link is higher than that of the first link; as well as In response to the fact that the quality of the second link is higher than that of the first link, it is determined to switch the physical downlink control channel from the first link to the second link.

8. The method according to any one of claims 1 to 5, wherein determining to switch the physical downlink control channel from the first link to the second link comprises: It is determined that the link quality of the first link is below a threshold; as well as In response to the link quality of the first link being lower than the threshold, it is determined to switch the physical downlink control channel from the first link to the second link.

9. The method according to any one of claims 1 to 8, wherein the request to switch the physical downlink control channel from the first link to the second link is sent via one of the following: User equipment auxiliary information, Scheduling request, L1 reference signal received power report L1 measurement report, or Channel state information.

10. The method according to any one of claims 1 to 9, further comprising: The network node receives confirmation of the request to switch the physical downlink control channel from the first link to the second link via the first link.

11. The method of claim 10, wherein the acknowledgment includes an indication to switch the physical downlink control channel from the first link to the second link, wherein the acknowledgment is received via one of the following: Media access control element. Downlink control information indication, or Radio Resource Control reconfiguration message.

12. The method of claim 11, further comprising: Based at least in part on the confirmation, the delay for the handover of the physical downlink control channel from the first link to the second link is determined.

13. The method of claim 11, wherein the acknowledgment is received via the downlink control information, the method further comprising: In response to the downlink control information indication, a hybrid automatic repeat request confirmation is sent to the network node; as well as Prepare to receive the physical downlink control channel via the second link at one of the following times: the time of transmission of the hybrid automatic repeat request acknowledgment, or the expected time of receipt of the hybrid automatic repeat request acknowledgment by the network node.

14. The method of claim 12, wherein the acknowledgment includes a hybrid automatic repeat request acknowledgment.

15. The method of claim 14, wherein the determined delay is based at least in part on the time of receiving the acknowledgment and the time of switching the physical downlink control channel.

16. An apparatus comprising: At least one processor; as well as At least one non-transitory memory, the at least one non-transitory memory storing instructions, the instructions, when executed by the at least one processor, cause the device to at least: Determine the quality of a first link with a first transmission point of a network node, wherein the first link is configured to carry a physical downlink control channel; Determine the quality of the second link with the second transmission point of the network node; Determine to switch the physical downlink control channel from the first link to the second link; as well as Send a request to the network node to switch the physical downlink control channel from the first link to the second link.

17. The apparatus of claim 16, wherein the first transmission point of the network node includes a first transmission and reception point of the network node, and wherein the second transmission point of the network node includes a second transmission and reception point of the network node.

18. The apparatus of claim 16 or 17, wherein the first link and the second link are configured to carry a physical downlink shared channel.

19. The apparatus according to any one of claims 16 to 18, wherein the at least one non-transitory memory stores an instruction, which, when executed by the at least one processor, causes the apparatus to: Send an indication to the network node that supports the capability of physical downlink control channel link switching; and Receive configuration from the network node that enables the switching of the physical downlink control channel link.

20. The apparatus according to any one of claims 16 to 19, wherein the at least one non-transitory memory stores an instruction, which, when executed by the at least one processor, causes the apparatus to: The second link is monitored for the physical downlink control channel.

21. The apparatus of any one of claims 16 to 20, wherein determining to switch the physical downlink control channel from the first link to the second link comprises: The at least one non-transitory memory stores an instruction, which, when executed by the at least one processor, causes the device to: It was determined that the link quality of the second link exceeded the threshold; and In response to the link quality of the second link exceeding the threshold, it is determined to switch the physical downlink control channel from the first link to the second link.

22. The apparatus of any one of claims 16-20, wherein determining to switch the physical downlink control channel from the first link to the second link comprises: The at least one non-transitory memory stores an instruction, which, when executed by the at least one processor, causes the device to: It is determined that the quality of the second link is higher than that of the first link; and In response to the fact that the quality of the second link is higher than that of the first link, it is determined to switch the physical downlink control channel from the first link to the second link.

23. The apparatus of any one of claims 16-20, wherein determining to switch the physical downlink control channel from the first link to the second link comprises: The at least one non-transitory memory stores an instruction, which, when executed by the at least one processor, causes the device to: It is determined that the link quality of the first link is below a threshold; as well as In response to the link quality of the first link being lower than the threshold, it is determined to switch the physical downlink control channel from the first link to the second link.

24. The apparatus of any one of claims 16 to 23, wherein the request to switch the physical downlink control channel from the first link to the second link is sent via one of the following: User equipment auxiliary information, Scheduling request, L1 reference signal received power report L1 measurement report, or Channel state information.

25. The apparatus according to any one of claims 16 to 24, wherein the at least one non-transitory memory stores an instruction, which, when executed by the at least one processor, causes the apparatus to: The network node receives confirmation of the request to switch the physical downlink control channel from the first link to the second link via the first link.

26. The apparatus of claim 25, wherein the acknowledgment includes an indication to switch the physical downlink control channel from the first link to the second link, wherein the acknowledgment is received via one of the following: Media access control element. Downlink control information indication, or Radio Resource Control reconfiguration message.

27. The apparatus of claim 26, wherein the at least one non-transitory memory stores instructions, the instructions, when executed by the at least one processor, cause the apparatus to: Based at least in part on the confirmation, the delay for the handover of the physical downlink control channel from the first link to the second link is determined.

28. The apparatus of claim 26, wherein the confirmation is received via the downlink control information indication, and the at least one non-transitory memory stores an instruction that, when executed by the at least one processor, causes the apparatus to: In response to the downlink control information indication, a Hybrid Automatic Repeat Request acknowledgment is sent to the network node; and Prepare to receive the physical downlink control channel via the second link at one of the following times: the time of transmission of the hybrid automatic repeat request acknowledgment, or the expected time of receipt of the hybrid automatic repeat request acknowledgment by the network node.

29. The apparatus of claim 27, wherein the confirmation includes a hybrid automatic repeat request confirmation.

30. The apparatus of claim 29, wherein the determined delay is based at least in part on the time of receiving the acknowledgment and the time of switching the physical downlink control channel.

31. A method comprising: Using a network node, a request is received from a user equipment to switch the physical downlink control channel from a first link to a second link, wherein the first link is provided via a first transmission point and the second link is provided via a second transmission point; as well as Send an acknowledgment to the user equipment of the request to switch the physical downlink control channel from the first link to the second link.

32. The method of claim 31, wherein the first transmission point includes a first transmission and reception point, and wherein the second transmission point includes a second transmission and reception point.

33. The method of claim 31 or 32, wherein the first link and the second link are configured to carry a physical downlink shared channel.

34. The method according to any one of claims 31 to 33, further comprising: Receive an indication from the user equipment of the capability to support physical downlink control channel link switching; as well as Send a configuration to the user equipment to enable the physical downlink control channel link switching.

35. The method of any one of claims 31 to 34, wherein the request to switch the physical downlink control channel from the first link to the second link is received via one of the following: User equipment auxiliary information, Scheduling request, L1 reference signal received power report L1 measurement report, or Channel state information.

36. The method of any one of claims 31 to 35, wherein the acknowledgment includes an indication to switch the physical downlink control channel from the first link to the second link, wherein the acknowledgment is sent via one of the following: Media access control element. Downlink control information indication, or Radio Resource Control reconfiguration message.

37. The method of claim 36, wherein the acknowledgment is sent via the downlink control information indication, the method further comprising: In response to the downlink control information indication, a hybrid automatic repeat request acknowledgment is received from the user equipment.

38. An apparatus comprising: At least one processor; as well as At least one non-transitory memory, the at least one non-transitory memory storing instructions, the instructions, when executed by the at least one processor, cause the device to at least: Receive a request from the user equipment to switch the physical downlink control channel from the first link to the second link, wherein the first link is provided via a first transmission point and the second link is provided via a second transmission point; as well as Send an acknowledgment to the user equipment of the request to switch the physical downlink control channel from the first link to the second link.

39. The apparatus of claim 38, wherein the first transmission point includes a first transmission and reception point, and wherein the second transmission point includes a second transmission and reception point.

40. The apparatus of claim 38 or 39, wherein the first link and the second link are configured to carry a physical downlink shared channel.

41. The apparatus according to any one of claims 38 to 40, wherein the at least one non-transitory memory stores an instruction, which, when executed by the at least one processor, causes the apparatus to: Receive from the user equipment an indication of the capability to support physical downlink control channel link switching; and Send a configuration to the user equipment to enable the physical downlink control channel link switching.

42. The apparatus of any one of claims 38 to 41, wherein the request to switch the physical downlink control channel from the first link to the second link is received via one of the following: User equipment auxiliary information, Scheduling request, L1 reference signal received power report L1 measurement report, or Channel state information.

43. The apparatus of any one of claims 38 to 42, wherein the acknowledgment includes an indication to switch the physical downlink control channel from the first link to the second link, wherein the acknowledgment is sent via one of the following: Media access control element. Downlink control information indication, or Radio Resource Control reconfiguration message.

44. The apparatus of claim 43, wherein the acknowledgment is sent via the downlink control information indication, and the at least one non-transitory memory stores an instruction that, when executed by the at least one processor, causes the apparatus to: In response to the downlink control information indication, a hybrid automatic repeat request acknowledgment is received from the user equipment.

45. An apparatus comprising components for: Determine the quality of a first link with a first transmission point of a network node, wherein the first link is configured to carry a physical downlink control channel; Determine the quality of the second link with the second transmission point of the network node; Determine to switch the physical downlink control channel from the first link to the second link; as well as Send a request to the network node to switch the physical downlink control channel from the first link to the second link.

46. ​​An apparatus comprising components for: Receive a request from the user equipment to switch the physical downlink control channel from a first link to a second link, wherein the first link is provided via a first transmission point, and wherein the second link is provided via a second transmission point; and Send an acknowledgment to the user equipment of the request to switch the physical downlink control channel from the first link to the second link.

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