UE-initiated switch of pdcch link in single-DCI scenario

Abstract

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

Description

UE-INITIATED SWITCH OF PDCCH LINK IN SINGLE-DCI SCENARIOTECHNICAL FIELD

[0001] The example and non-limiting embodiments relate generally to the link used for PDCCH transmission in a multi-TRP configuration and, more particularly, to switching of that PDCCH link.BACKGROUND

[0002] It is known, in cellular communication, to use transmission configuration indication states to configuration a UE with gNB transmission information.SUMMARY

[0003] The following summary is merely intended to be illustrative. The summary is not intended to limit the scope of the claims.

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

[0005] In accordance with one aspect, a method comprising: determining, with a user equipment, a 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; determining a qualityof a second link with a second transmission point of the network node; determining to switch the physical downlink control channel from the first link to the second link; and transmitting, to the network node, a request to switch the physical downlink control channel from the first link to the second link.

[0006] In accordance with one aspect, an apparatus comprising means for: determining a 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; determining a quality of a second link with a second transmission point of the network node; determining to switch the physical downlink control channel from the first link to the second link; and transmitting, to the network node, a request to switch the physical downlink control channel from the first link to the second link.

[0007] In accordance with one aspect, a non-transitory computer-readable medium comprising program instructions stored thereon for performing at least the following: determining a 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; determining a quality of a second link with a second transmission point of the network node; determining to switch the physical downlink control channel from the first link to the second link; and causing transmitting, to the network node, of a request to switch the physical downlink control channel from the first link to the second link.

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

[0009] In accordance with one aspect, a method comprising: receiving, with a network node 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, wherein the second link is provided via a second transmission point; and transmitting, to theuser equipment, an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

[0010] In accordance with one aspect, an apparatus comprising means 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, wherein the second link is provided via a second transmission point; and transmitting, to the user equipment, an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

[0011] In accordance with one aspect, a non-transitory computer-readable medium comprising program instructions stored thereon for performing at least the following: causing receiving, from a user equipment, of 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, wherein the second link is provided via a second transmission point; and causing transmitting, to the user equipment, of an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

[0012] According to some aspects, there is provided the subject matter of the independent claims. Some further aspects are defined in the dependent claims.BRIEF DESCRIPTION OF THE DRAWINGS

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

[0014] FIG. 1 is a block diagram of one possible and non-limiting example system in which the example embodiments may be practiced;

[0015] FIG. 2 is a diagram illustrating features as described herein;

[0016] FIG. 3 is a diagram illustrating features as described herein;

[0017] FIG. 4 is a diagram illustrating features as described herein;

[0018] FIG. 5 is a diagram illustrating features as described herein;

[0019] FIG. 6 is a diagram illustrating features as described herein;

[0020] FIG. 7 is a diagram illustrating features as described herein;

[0021] FIG. 8 is a diagram illustrating features as described herein;

[0022] FIG. 9 is a diagram illustrating features as described herein;

[0023] FIG. 10 is a flowchart illustrating steps as described herein; and

[0024] FIG. 11 is a flowchart illustrating steps as described herein.DETAILED DESCRIPTION OF EMBODIMENTS

[0025] The following abbreviations that may be found in the specification and / or the drawing figures are defined as follows:3GPP third generation partnership project5G fifth generation5GC 5G core networkACK acknowledgementAMF access and mobility management functionAoA angle of arrivalAoD angle of departureBFD beam failure detectionBFD-RS beam failure detection reference signalBM-RS beam management reference signalCBD candidate beam detectionCE control elementCORESET control resource set cRAN cloud radio access networkCSI channel state informationCSLRS channel state information reference signalCSLRSRP channel state information reference signal -based reference signal received powerCU central unitDCI downlink control informationDM-RS (or DMRS) demodulation reference signalDU distributed unit eNB (or eNodeB) evolved Node B (e.g., an LTE base station)EN-DC E-UTRA-NR dual connectivity en-gNB or En-gNB node providing NR user plane and control plane protocol terminations towards the UE, and acting as secondary node in EN-DCE-UTRA evolved universal terrestrial radio access, i.e., the LTE radio access technologyFRS frequency range 2 gNB (or gNodeB) base station for 5G / NR, i.e., a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GCHARQ hybrid automatic repeat requestI / F interfaceLI layer 1LTE long term evolutionMAC medium access controlMAC-CE medium access control control elementMIMO multiple input multiple outputMME mobility management entityM-TRP multiple transmit / receive point ng or NG new generation ng-eNB or NG-eNB new generation eNBNR new radioN / W or NW networkNZP CSI-RS non zero power channel state information reference signalO-RAN open radio access networkPBCH physical broadcast channelPCID primary cell IDPDCCH physical downlink control channelPDCP packet data convergence protocolPDSCH physical downlink shared channelPHY physical layerPUCCH physical uplink control channelPUSCH physical uplink shared channelQCL quasi co-locationRAN radio access networkRF radio frequencyRLC radio link controlRLM radio link monitoringRRC radio resource controlRRH remote radio headRRM radio resource managementRS reference signalRU radio unitRx receiverSDAP service data adaptation protocol sDCI (or s-DCI) single downlink control informationSFN single frequency networkSGW serving gatewaySMF session management functionSR scheduling requestSRS sounding reference signalSS synchronization signalSSB synchronization signal blockTCI transmission configuration indicatorTRP transmission-reception pointTRS tracking reference signalTx transmitterUE user equipment (e.g., a wireless, typically mobile device)UPF user plane functionVNR virtualized network functionWI work item

[0026] Turning to FIG. 1, this figure shows a block diagram of one possible and nonlimiting example in which the examples may be practiced. A user equipment (UE) 110, radio access network (RAN) node 170, and network element(s) 190 are illustrated. In the example of FIG. 1, the user equipment (UE) 110 is in wireless communication with a wireless network 100. A UE is a wireless device that can access the wireless network 100. The UE 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected through 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 address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, and the like. A “circuit” may include dedicated hardware or hardware in association with software executable 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. The UE 110 includes a module 140, comprising one of or both parts 140- 1 and / or 140-2, which may be implemented in a number of ways. The module 140 may be implemented in hardware as module 140-1, such as being implemented as part of the one or more processors 120. The module 140-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the module 140 may be implemented as module 140-2, which is implemented as computer program code 123 and is executed by the one or more processors 120. For instance, the one or more memories 125 and the computer program code 123 may be configured to, with the one or more processors 120, cause the user equipment 110 to perform one or more of the operations as described herein. The UE 110 communicates with RAN node 170 via a wireless link 111.

[0027] The RAN node 170 in this example is a base station that provides access by wireless devices such as the UE 110 to the wireless network 100. The RAN node 170 may be, for example, a base station for 5G, also called New Radio (NR). In 5G, the RAN node 170 may be a NG-RAN node, which is defined as either a gNB or a ng-eNB. A gNB is a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface to a 5GC (such as, for example, the network element(s) 190).The ng-eNB is a node providing E-UTRA user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC. The NG-RAN node may include multiple gNBs, which may also include a central unit (CU) (gNB-CU) 196 and distributed unit(s) (DUs) (gNB-DUs), of which DU 195 is shown. Note that the DU may include or be coupled to and control a radio unit (RU). The gNB-CU is a logical node hosting RRC, SDAP and PDCP protocols of the gNB or RRC and PDCP protocols of the en-gNB that controls the operation of one or more gNB-DUs. The gNB-CU terminates the Fl interface connected with the gNB-DU. The Fl interface is illustrated as reference 198, although reference 198 also illustrates a link between remote elements of the RAN node 170 and centralized elements of the RAN node 170, such as between the gNB-CU 196 and the gNB- DU 195. The gNB-DU is a logical node hosting RLC, MAC and PHY layers of the gNB or en-gNB, and its operation is partly controlled by gNB-CU. One gNB-CU supports one or multiple cells. One cell is supported by only one gNB-DU. The gNB-DU terminates the Fl interface 198 connected with the gNB-CU. Note that the DU 195 is considered to include the transceiver 160, e.g., as part of a RU, but some examples of this may have the transceiver 160 as part of a separate RU, e.g., under control of and connected to the DU 195. The RAN node 170 may also be an eNB (evolved NodeB) base station, for ETE (long term evolution), or any other suitable base station, access point, access node, or node.

[0028] The RAN node 170 includes one or more processors 152, one or more memories 155, one or more network interfaces (N / W I / F(s)) 161, and one or more transceivers 160 interconnected through 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. The CU 196 may include the processor(s) 152, memories 155, and network interfaces 161. Note that the DU 195 may also contain its own memory / memories and processor(s), and / or other hardware, but these are not shown.

[0029] The RAN node 170 includes a module 150, comprising one of or both parts 150- 1 and / or 150-2, which may be implemented in a number of ways. The module 150 may be implemented in hardware as module 150-1, such as being implemented as part of the one or more processors 152. The module 150-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the module150 may be implemented as module 150-2, which is implemented as computer program code 153 and is executed by the one or more processors 152. For instance, the one or more memories 155 and the computer program code 153 are configured to, with the one or more processors 152, cause the RAN node 170 to perform one or more of the operations as described herein. Note that the functionality of the module 150 may be distributed, such as being distributed between the DU 195 and the CU 196, or be implemented solely in the DU 195.

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

[0031] The one or more buses 157 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, wireless channels, and the like. For example, the one or more transceivers 160 may be implemented as a remote radio head (RRH) 195 for LTE or a distributed unit (DU) 195 for gNB implementation for 5G, with the other elements of the RAN node 170 possibly being physically in a different location from the RRH / DU, and the one or more buses 157 could be implemented in part as, for example, fiber optic cable or other suitable network connection to connect the other elements (e.g., a central unit (CU), gNB-CU) of the RAN node 170 to the RRH / DU 195. Reference 198 also indicates those suitable network link(s).

[0032] It is noted that description herein indicates that “cells” perform functions, but it should be clear that equipment which forms the cell will perform the functions. The cell makes up part of a base station. That is, there can be multiple cells per base station. For example, there could be three cells for a single carrier frequency and associated bandwidth, each cell covering one-third of a 360 degree area so that the single base station’s coverage area covers an approximate oval or circle. Furthermore, each cell can correspond to a single carrier and a base station may use multiple carriers. So if there are three 120 degree cells per carrier and two carriers, then the base station has a total of 6 cells.

[0033] The wireless network 100 may include a network element or elements 190 that may include core network functionality, and which provides connectivity via a link or links181 with a further network, such as a telephone network and / or a data communications network (e.g., the Internet). Such core network functionality for 5G may include access and mobility management function(s) (AMF(s)) and / or user plane functions (UPF(s)) and / or session management function(s) (SMF(s)). Such core network functionality for LTE may include MME (Mobility Management Entity) / SGW (Serving Gateway) functionality. These are merely illustrative functions that may be supported by the network element(s) 190, and note that both 5G and LTE functions might be supported. The RAN node 170 is coupled via a link 131 to a network element 190. The link 131 may be implemented as, e.g., an NG interface for 5G, or an SI interface for LTE, or other suitable interface for other standards. The network element 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces (N / W I / F(s)) 180, interconnected through one or more buses 185. 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, with the one or more processors 175, cause the network element 190 to perform one or more operations.

[0034] The wireless network 100 may implement network virtualization, which is the process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Network virtualization involves platform virtualization, often combined with resource virtualization. Network virtualization is categorized as either external, combining many networks, or parts of networks, into a virtual unit, or internal, providing network-like functionality to software containers on a single system. For example, a network may be deployed in a tele cloud, with virtualized network functions (VNF) running on, for example, data center servers. For example, network core functions and / or radio access network(s) (e.g. CloudRAN, O-RAN, edge cloud) may be virtualized. Note that the virtualized entities that result from the network virtualization are still implemented, at some level, using hardware such as processors 152 or 175 and memories 155 and 171, and also such virtualized entities create technical effects.

[0035] It may also be noted that operations of example embodiments of the present disclosure may be carried out by a plurality of cooperating devices (e.g. cRAN).

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

[0037] In general, the various example embodiments of the user equipment 110 can include, but are not limited to, cellular telephones such as smart phones, tablets, personal digital assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, Internet appliances permitting wireless Internet access and browsing, tablets with wireless communication capabilities, as well as portable units or terminals that incorporate combinations of such functions.

[0038] Having thus introduced one suitable but non-limiting technical context for the practice of the example embodiments of the present disclosure, example embodiments will now be described with greater specificity.

[0039] Features as described herein may generally relate to use of multiple transmit / receive points (M-TRP). An NR cell may comprise one or multiple TRPs. TRPs of the same cell have a common synchronization (SS) and / or physical broadcast channel (PBCH) block which is cell specific. In multiple transmit / receive point (multi-TRP) operation, a serving cell can schedule the UE from two TRPs, providing better coverage, reliability and / or data rates for 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 different operation modes to schedule multi-TRP PDSCH transmissions: single-DCI (sDCI) and multi-DCI. For both modes, control of uplink anddownlink operation can be done by the physical layer and the MAC layer within the configuration provided by the radio resource control (RRC) layer. In single-DCI mode, only one TRP is responsible for the transmission of control data (i.e. PDCCH) to the UE. As a result, the UE is scheduled by the same PDCCH containing a DCI for both TRPs. In contrast, in multi-DCI mode, two TRPs are responsible for the transmission of control data to the UE. As a result, the UE is scheduled by independent DCIs from each TRP.

[0041] Features as described herein may generally relate to beam management. 3GPP- defined 5G NR Frequency Range 2 bands have huge bandwidths which can cater to 5G NR use cases requiring higher data rates. However, these bands are also subject to challenging radio propagation conditions such as high path loss, absorption from the environment, and penetration losses, to name a few. To overcome these, beam management procedures have been defined in 3GPP.

[0042] Beam Management is a set of procedures to assist UE to set its receive (Rx) and transmit (Tx) beams for downlink and uplink transmissions, respectively. NR supports a hierarchical beam-based approach with the synchronization signal block (SSB) beam being the root beam, as illustrated in FIG. 2. In the beam hierarchy example of Level 1 : SS / PBCH block “beams” (210), SSB #1, SSB #m, and SSB #n partially overlap with each other. In the beam hierarchy example of Level 2-n: CSLRS “beams” (220), SSB #m, and SSB #n partially overlap with each other, and SSB #n comprises CSLRS #0 (associated to SSB #n), CSI-RS #1 (associated to SSB #n), CSI-RS #2 (associated to SSB #n), and CSI-RS #3 (associated to SSB #n).

[0043] Features as described herein may generally relate to transmission configuration indicator (TCI) states. A quasi co-location (QCL) framework is used for beam indication. The gNB provided beam indication information is used to configure the UE with information about which gNB transmit (Tx) beam is to be used for downlink (DL) (i.e. so that the UE can select proper spatial Receive Rx settings), and which Rx beam is to be used for uplink (UL) (i.e. so that the UE’s Tx is directed towards correct RX beam at gNB).

[0044] Each TCI state contains parameters for configuring a quasi-co-location relationship between one or two downlink reference signals (RS) and the demodulationreference signal (DM-RS) port(s) of the PDSCH, the DM-RS port(s) of the PDCCH, or the channel state information reference signal (CSI-RS) port(s) of a CSI-RS resource.

[0045] The quasi-co-location types corresponding to each DL RS are given by the higher layer parameter qcl-Type in QCL-Info and may take one of the following values:QCL types A: Doppler shift, Doppler spread, average delay, delay spreadQCL types B : Doppler shift, Doppler spreadQCL types C: average delay, Doppler shiftQCL types D: Spatial Rx

[0046] The main tool for beam indication for downlink is a TCI framework. In Rel-15 / 16, TCI states were defined only for downlink, whereas uplink spatial relation was used for uplink. In Rel-17, a unified TCI state framework was introduced to cover both downlink and uplink. In the following, we describe these approaches in more detail.

[0047] Rel-15 / 16 TCI framework

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

[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, where the SSB can be associated with a serving cell primary cell ID (PCID) or with a PCID different from the serving cell PCID.

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

[0051] Referring now to FIG. 3, illustrated is an example of QCL and TCI chain(s).

[0052] The signaling related to DL TCI states is the following:- Up to 128 TCI states are configured to the UE with RRC.- For PDCCH: 1 TCI state is indicated by DL MAC CE- For PDSCH: Up to 8 TCI states can be activated in codepoint (active TCI state list) with DL MAC CE. Out of these, 1 TCI state is indicated for PDSCH with DO.

[0053] For Rel-15 / 16 TCI state activation / indication, RAN4 has defined delay requirements for:- MAC CE based TCI state switch, meaning MAC CE indication of a TCI state for PDCCH- DCI based TCI state switch, meaning DCI indication of a TCI state for PDSCH- RRC based TCI state switch, meaning switching to a TCI state through RRC reconfiguration.- Active TCI state list update, meaning activation / addition of PDSCH TCI state(s) to the active TCI state list

[0054] In the multi-TRP single-DCI scenario, a single TCI state is indicated for PDCCH for the link that carries PDCCH. For PDSCH, single TCI states or TCI state pairs can be activated into the active TCI state list, and one of these TCI states or TCI state pairs can be indicated with DCI. RAN4 is currently working on delay requirements for the multi-TRP scenarios using the Rel-15 / 16 TCI states as the baseline.

[0055] Unified TCI state framework

[0056] The unified TCI state framework was specified by 3GPP in Rel-17. In Rel-15 / 16, TCI states were only configured for downlink, while uplink spatial relation covered the beam indication for uplink. With the unified TCI state concept, TCI states are configured for both downlink and uplink. The configuration is either joint, where same TCI state covers both UL and DL, or separate, where there are separate TCI states configured for DL and UL.

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

[0058] Assigning the unified TCI states is done with the following steps:- RRC-based configuration of up to 128 TCI states.- MAC-CE-based activation of up to 16 TCI states into 8 codepoints.- DCI-based indication of a single joint TCI state or TCI state pair of DL and UL TCI states.

[0059] RAN4 has defined delay requirements for: MAC CE based DL and UL TCI state switch; DCI based DL and UL TCI state switch; and active DL and UL TCI state list update. RAN4 agreed to use Rel-15 / 16 TCI states for the multi-Rx feature, but in the future releases, unified TCI states are also expected to be covered. The principle used in single-DCI scenario can be expected to be similar to Rel-15 / 16 TCI states management principles.

[0060] Features as described herein may generally relate to link quality monitoring in the single-DCI mode. Radio link monitoring (RLM) is done on PDCCH. Only one of the links in s-DCI mode has PDCCH configured; in other words, RLM in single-DCI reception only applies for the link with PDCCH. Out-of-sync indication, in-sync indication, and radio link failure is based on RLM-RS received on this anchor link (i.e. implicitly based on the RS indicated by the TCI state for PDCCH). There is no RLM on the other link, which only has PDSCH.

[0061] Beam failure detection (BFD) and candidate beam detection (CBD) is done on PDCCH. Only one of the links in s-DCI mode has PDCCH configured; in other words, BFD / CBD in single-DCI reception only applies for the link with PDCCH and therefore, this is similar to the single-TRP scenario. There is no BFD / CBD on the link which only has PDSCH (i.e. the RS associated with PDSCH reception is not monitored for beam failure detection). Referring now to FIG. 4, illustrated is an example of how RLM and BFD / CBD in single-DCI reception only applies for the link with PDCCH. In the example, TRP 1 (410) provides PDSCH (420) and PDCCH (430) to the UE (450), while TRP 2 (460) provides PDSCH (470) to the UE (450).

[0062] It may be noted that R4-2307348 provides discussion on RLM and BFD / CBD for NR FR2 multi-Rx chain DL reception. It may be noted that R4-2304133 provides discussion on RLM and BFD / CBD for NR FR2 multi-Rx chain DL reception. It may be noted that R4- 2305190 describes UE initiated TCI state switch. Referring now to FIG. 5, illustrated is an example of a UE-initiated TCI state switch, described as follows:. .UE-initiated beam selection / activation could be one alternative to reduce the beam activation latency. Based on beam measurements, UE can select one (i.e., beam selection) or more (i.e., beam activation) TCI states as active and report it / them to network. Since the TCI state(s) is(are) selected / activated by UE, UE is responsible to remember the QCL properties of DL RS(s) associated with the selected TCI state(s). Thus, the measurement in reporting is not needed anymore. Once network response on the report is received by UE, the selected / activated TCI states can be immediately used for DL reception. Since UE-initiated beam activation / deactivation merges beam report and beam activation into one step, the latency can be greatly reduced. . .”

[0063] In the single-DCI scenario, the network may configure PDCCH to be transmitted from any of the two TRPs. Ideally, PDCCH may be considered to be transmitted from the TRP that has better radio link conditions.

[0064] The network may use the available information in deciding on which of the links PDCCH is configured. It is not specified how the network selects the PDCCH link. The UE has additional information on its side, such as out-of-sync / in-sync indications and beam failure indications, about which the network has no visibility.

[0065] In the single-DCI scenario, because radio link monitoring and beam failure detection applies only to the link with PDCCH configured, the network has limited knowledge of the radio link conditions on the link with only PDSCH configured. It may happen that the link with PDCCH experiences worse radio link conditions than the link with PDSCH only, but this is not visible to the network through RLM and BFD procedures.

[0066] A technical effect of example embodiments of the present disclosure may be to, in a multi-TRP scenario using sDCI DL scheduling mode, ensure that the PDCCH is timely scheduled on the best TRP link when radio conditions are changing with FR2 UE mobility.

[0067] In a single-DCI multi-TRP scenario, the UE may be scheduled for PDSCH on both links, but PDCCH may only be scheduled on one of the TRP links. The UE may evaluate / determine that the downlink radio link conditions on the link with only PDSCH are more optimal for scheduling PDCCH than the conditions on the link where PDCCH is currently scheduled. However, this condition may not be instantaneously known to the network.Example embodiments of the present disclosure may provide signaling and / or a reporting mechanism in such a scenario. A technical effect of example embodiments of the present disclosure may be to mitigate such a scenario. A technical effect of example embodiments of the present disclosure may be to enable the visibility of the scenario described above to the network and to allow optimized PDCCH scheduling between the two TRPs.

[0068] In an example embodiment, a UE may trigger a newly defined PDCCH link switch signal, which may have the technical effect of enabling the network to react fast to deteriorating radio conditions on the main TRP link which schedules PDCCH.

[0069] In an example embodiment, the new PDCCH link switch signaling from the UE may inform the network that the UE prefers to switch the PDCCH from the current TRP link on which it is scheduled to the other TRP link where only PDSCH is scheduled, for example when certain (UE determined e.g., radio link and beam quality evaluation or LI or L3 measurement) thresholds / conditions are exceeded / met.

[0070] In an example embodiment, if the network accepts the UE request of the PDCCH link switch, the network may indicate (via new signaling, e.g. DCI) its acknowledgement of a PDCCH link switch to the UE. In an example embodiment, a PDCCH switching delay may be defined, which may have the technical effect of providing the NW with information as to when to transmit, with the new requested PDCCH, to the UE.

[0071] Alternatively, in an example embodiment an explicit TCI state switch command / acceptance of switch from the network may not be needed. The PDCCH may be switched to the other TCI state used by UE in DL unconditionally, for example based on the UE request. In other words, acceptance of the switch may only be implied. In an example embodiment, a PDCCH switching delay may be defined, which may have the technical effect of providing the NW with information as to when to transmit, with the new requested PDCCH, to the UE.

[0072] In the present disclosure, a “PDCCH+PDSCH link” may refer to the link between the UE and TRP1, where PDSCH and PDCCH are configured. In the present disclosure, a “PDSCH-only link” may refer to the link between the UE and TRP2, where only PDSCH is configured.

[0073] In an example embodiment, the UE may indicate the UE-initiated switch of PDCCH link.

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

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

[0076] In an example embodiment, the UE may be configured to indicate link switch when it determines that the current PDCCH+PDSCH link has a quality below a threshold value, which may be a threshold value based on the UE.

[0077] In an example embodiment, the UE may receive a network indication to switch the PDCCH link. In an example embodiment, when the UE has been configured with a link switch, it may receive a network indication that commands the link switch.

[0078] In an example embodiment, upon detecting the link switch command by the NW, the UE may be expected / configured to monitor the PDCCH on the TCI state previously indicated for PDSCH reception on the PDSCH-only link (i.e. the UE may assume that the previous PDSCH TCI state is to be used as the indicated TCI state for PDCCH).

[0079] In an example embodiment, upon detecting the link switch command by the NW, the UE may be expected / configured to monitor the PDSCH on the TCI state previouslyindicated for PDCCH reception on the PDCCH-PDSCH link (i.e. the UE may assume that the previous PDCCH TCI state is to be used as the indicated TCI state for PDSCH).

[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 indicates to the UE to monitor PDCCH and receive PDSCH on the indicated TCI state, and the second indicated TCI state may be for PDSCH reception.

[0081] Referring now to FIG. 6, illustrated is an example of TCI states at PDCCH link switch. In the example of FIG. 6, it is assumed that, on the PDCCH-PDSCH link, the same TCI state is used with TRP 1 (610) for PDCCH (620) and PDSCH (630), TCI#0. This may mean use of a unified TCI state, in which case one common TCI state is used for PDSCH and PDCCH, or Rel-15 / 16 TCI states, where PDCCH and PDSCH TCI states are indicated separately, but the same actual TCI state may be used for both. For TRP 2 (640), TCI#1 (650) may be used for PDSCH. After the switch (660), for TRP 1 (610), TCI#0 may be used for PDSCH (670), while for TRP 2 (640), TCI#1 may be used for PDCCH (680) and for PDSCH (690). This may mean that TCI#1 is used as a unified TCI state.

[0082] In an example embodiment, upon providing the indication to the network, the UE may expect the NW to respond using, for example, a new DCI based indication that indicates the link switch procedure. The DCI indication may be included in a current DCI format or a new format. The indication may be, for example, a 1 bit (ACK) indication. In an example embodiment, upon providing the indication to the network, the UE may expect the NW to respond using, for example, a MAC CE triggering the link switch.

[0083] In an example embodiment, the link switch indication configuration may be provided using an RRC configuration. In an example embodiment, the RRC configuration may indicate whether the UE is expected to do the PDDCH link switching due to the link quality degradation. In an example embodiment, the link switch indication may be dynamically configured.

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

[0085] Referring now to FIG. 7, illustrated is UE and network signaling to achieve PDCCH link switch according to an example embodiment of the present disclosure. In the example of FIG. 7, TRP1 and TRP2 may belong to a same network node. In the example of FIG. 7, it is assumed that, in addition to PDCCH, uplink is also configured on TRP1, which is why all the UE signaling towards the network is going to TRP1.

[0086] At 705, the UE may be in a single-DCI multi-TRP mode. The UE may be scheduled with PDCCH and PDSCH from TRP1. The UE may be scheduled with PDSCH from TRP2. At 710, the UE may receive PDSCH from TRP2. At 715, the UE may signal the capability to support UE initiated PDCCH link switch indication. The UE capabilities may be included in pdcch-Switching-in-sDCI. At 720, the network may enable the UE initiated indication of PDCCH link switch. The indication to enable the PDCCH link switch may be transmitted to the UE from TRP1 via an RRCReconfiguration message. The message may comprise OtherConfig-v 1800 and / or pdcch-Switching-in-sDCI=enabled. At 725, the UE may evaluate the link quality of the two links, for example based on L1 / L3 RSRP, and conclude that the quality of the PDSCH-only link from TRP2 would be better for PDCCH reception than the current PDCCH+PDSCH link from TRP1.

[0087] At 735 / 745, the UE may indicate to the network that it would prefer PDCCH to be switched to the other link. In the example of FIG. 7, Option A (730) and Option B (740) are alternative options to each other. In Option A (730), at 735, the indication may be sent in UE assistance information. The UE assistance information may comprise pdcch-Switching- in-sDCI (request to switch PDCCH to TRP2). In Option B (740), at 745, the indication may be included in an LI measurement report. The LI measurement report may comprise pdcch- Switching-in-sDCI (request to switch PDCCH to TRP2).

[0088] At 750, the network may accept the UE request to switch the PDCCH to the other link (i.e. from TRP1 to TRP2). At 760 / 770 / 780, the network may explicitly acknowledge the PDCCH link switch to the UE. In the example of FIG. 7, Option 1 (755), Option 2 (765), and Option 3 (775) are alternative options to each other. In Option 1 (755), at 760, the PDCCH link switch may be indicated by DL MAC-CE containing an indication field to acknowledge link switch. The DL MAC-CE may comprise an indication to switch PDCCH to TRP2. In Option 2 (765), at 770, the PDCCH link switch may be indicated by DO containing anindication field to acknowledge switch. The DCI may comprise an indication to switch PDCCH to TRP2. In Option 3 (775) at 780, the PDCCH link switch may be indicated by RRC reconfiguration. The RRCReconfiguration message may comprise an indication to switch PDCCH to TRP2.

[0089] At 785, the PDCCH link switch from TRP1 to TRP2 may be performed, including the TCI state switch related steps disclosed above. At 790, the UE may be scheduled with PDSCH from TRP1. At 795, the UE may be scheduled with PDCCH and PDSCH from TRP2. Accordingly, the PDCCH link has been switched.

[0090] Referring now to FIG. 8, illustrated is UE and network signaling to achieve PDCCH link switch according to an alternative example embodiment of the present disclosure. In the example of FIG. 8, TRP1 and TRP2 may belong to a same network node.

[0091] At 805, the UE may be in a single-DCI multi-TRP mode. The UE may be scheduled with PDCCH and PDSCH from TRP1. At 810, the UE may be scheduled with PDSCH from TRP2. At 815, the UE may signal the capability to support the UE initiated PDCCH link switch indication. The UE capabilities may be signaled to TRP1 via pdcch- Switching-in-sDCI. At 820, the network may enable the UE initiated indication of PDCCH link switch. This may be indicated via RRCReconfiguration message, which may comprise OtherConfig-v 1800 and / or pdcch-Switching-in-sDCI=enabled. At 825, the UE may evaluate the link quality of the two links based on, for example, L1 / L3 RSRP, and conclude that the quality of PDSCH-only link from TRP2 would be better for PDCCH reception than the current PDCCH+PDSCH link from TRP1.

[0092] At 835 / 845, the UE may indicate to the network that it would prefer PDCCH to be switched to the other link. In the example of FIG. 8, Option A (830) and Option B (840) are alternative options to each other. In Option A (830), at 835, the indication may be sent in UE assistance information. The UE assistance information may comprise pdcch-Switching- in-sDCI (request to switch PDCCH to TRP2). In Option B (840), at 845, the indication may be included in an LI measurement report. The LI measurement report may comprise pdcch- Switching-in-sDCI (request to switch PDCCH to TRP2).

[0093] At 850, the UE may receive a Ll-HARQ acknowledgement for messages in Option A (830) or Option B (840). This may be an implicit indication of the network having acknowledged the PDCCH link switch. At 855, the PDCCH link switch from TRP1 to TRP2 may be performed, including the TCI state switch related steps disclosed above. At 860, the UE may be scheduled with PDSCH from TRP1. At 865, the UE may be scheduled with PDCCH and PDSCH from TRP2. Accordingly, the PDCCH link has been switched.

[0094] In an example embodiment, a predefined delay requirement may be defined for the UE initiated PDCCH switch. The definition of the delay may be different depending on which type of message is used to indicate the switch (e.g. HARQ ACK, DO, MAC-CE, RRC, etc.). The delay may be, for example, the time from the moment the UE receives / decodes the message indicating the switch until the time the UE is able to receive PDCCH from the target TRP. The delay may be defined either in RAN 1 or RAN4 specification.

[0095] For example, TCI state switching delays are currently defined in TS 38.133:“...8.10.3 MAC-CE based TCI state switch delayIf the target TCI state is known, upon receiving PDSCH carrying MAC-CE activation command in slot n, UE shall be able to receive PDCCH with target TCI state of the serving cell on which TCI state switch occurs at the first slot that is after slot n+t-ssB + TssB-proc) / NR slot length. The UE shall be able to receive PDCCH with the old TCI state until slot n-i- THARQ + 3N^frame,,i. Where THARQ is the timing between DL data transmission and acknowledgement as specified in TS 38.213 [3];Tfirst-SSB is time to first SSB transmission after MAC CE command is decoded by the UE; The SSB shall be the QCL-TypeA or QCL-TypeC to target TCI stateTssB-proc — 2 ms;TOk = 1 if target TCI state is not in the active TCI state list for PDSCH, 0 otherwise.8.10.4 DCI based TCI state switch delayIf the target TCI state is known, when a UE is configured with the higher layer parameter tci-PresentlnDCI which is set as 'enabled' for the CORESET scheduling PDSCH at slot n, UE shall be able to receive PDSCH with target TCI state of the serving cell on which TCI state switch occurs at the first slot that is after slot n+timeDurationForQCL, where, timeDurationForQCL is the time required by the UE to perform PDCCH reception and applying spatial QCL information received in DCI for PDSCH processing as described in TS 38.214

[0026] , the value of timeDurationForQCL is defined in TS 38.331 [2].The known condition for TCI state defined in clause 8.10.2 is applied.8.15.4 DCI based downlink TCI state switch delayWhen a UE is configured with the higher layer parameter with DLorJointTCIState or UL-TCIState, activated with TCI states for downlink transmission by MAC CE indication of more than one codepoints, and receives DCI format 1_1 / 1_2 with or without DL assignment providing indicated TCI-State or TCI state pair in the active TCI list for a CC, the UE transmits a PUCCH with HARQ-ACK information corresponding to the DCI carrying the TCI-State indication. . .”

[0096] Hence, we can conclude that, in legacy requirements, for MAC CE based PDCCH switch, assuming that target TCI state is known (already used for DL reception of PDSCH from TRP2), the UE shall be able to receive PDCCH with target TCI state of the serving cell on which TCI state switch occurs at the first slot that is after slot n-i- THARQ + 2N^ob rame,ti. We can also conclude that, in legacy requirements, DCLbased PDCCH switch is defined only for unified TCI framework, and no delay is defined, when UE shall be able to receive PDCCH with the new / target TCI state.

[0097] Depending on the implementation of the new PDCCH switch requested by the UE (e.g. FIG. 7, 8), the following requirements on UE PDCCH switching may be foreseen.

[0098] For example, a new DCI command from the NW to the UE may be used to accept the UE-requested switch of PDCCH from TRP1 to TRP2. The UE may receive PDCCH with PDCCH state switch acknowledgment / indication in slot n. In one option, the UE may be able to receive PDCCH with the target TCI state of the serving cell on which the TCI state switch occurs at the first slot, that is, after slot n+X ms, where, X ms may be the time required by the UE to perform PDCCH reception and switching PDCCH to the new TCI state (e.g. to the new TRP, UE panel, etc.). In another option, the UE may send an HARQ-ACK information corresponding to the DCI (e.g. if DCI format 1_1 / 1_2 is used) carrying the requested PDCCH state switch acknowledgment / indication. In this case, no specific switching delay may be defined because the UE is assumed to be ready to receive over the new PDCCH at the moment of HARQ-ACK transmission or its expected reception at the NW side.

[0099] For example, an explicit NW indication / acknowledgment of PDCCH switch may not be used (i.e. PDCCH switch may take place based on UE indication only, for example because the TCI state is already used for PDSCH). Accordingly, the following UE requirement(s) may be introduced. For example, after the PDCCH switch request is received from the UE, the NW may send HARQ-ACK in response. The UE may receive HARQ-ACK to the PDCCH switch request in slot n. The UE may be able to receive PDCCH with the target TCI state of the serving cell on which TCI state switch occurs at the first slot, that is, after slot n+Y ms, where Y ms may be the time required by the UE to perform PDCCH / HARQ-ACK reception and switching PDCCH to the new TCI state (e.g. to the new TRP, UE panel, etc.)

[0100] Example embodiments of the present disclosure may involve new signaling aspects, which may be covered in RAN2 specifications. When considering RAN2 aspects, the specification may include support for the gNB indicating, for the UE, that it may send an indication of UE capabilities of the UE initiated PDCCH link switching. Referring now to FIG. 9, illustrated is an example of a new parameter to signal UE capability for PDCCH link switching in the sDCI scenario. At 910, pdcch-Switching-in-sDCI element may optionally be included in the UECapabilitylnformation. This element may signal the UE capability for PDCCH link switching in the sDCI scenario.

[0101] A technical effect of example embodiments of the present disclosure may be to enable an early, quick PDCCH (TRP) link switch to be made between the already monitoredTCI state(s) by the network when the PDCCH link quality is deteriorating, but the link to the other TRP is still good. A technical effect of example embodiments of the present disclosure may be to improve the beam quality monitoring in the s-DCI scenario. A technical effect of example embodiments of the present disclosure may be to avoid beam failure, which may save on the overhead of radio link failure procedure(s) and / or beam failure recovery procedure(s).

[0102] FIG. 10 illustrates the potential steps of an example method 1000. The example method 1000 may include: determining a 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 a 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 transmitting, to the network node, a request to switch the physical downlink control channel from the first link to the second link, 1040. The example method 1000 may be performed, for example, with a UE.

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

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

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

[0106] The first link and the second link may be configured to carry a physical downlink shared channel.

[0107] The example apparatus may be further configured to: transmit, to the network node, an indication of a capability to support physical downlink control channel link switching; and receive, from the network node, a configuration to enable the physical downlink control channel link switching.

[0108] The example apparatus may be further configured to: monitor the 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 comprise the example apparatus being further configured to: determine that a link quality of the second link exceeds a threshold; and determine to switch the physical downlink control channel from the first link to the second link in response to the link quality of the second link exceeding the threshold.

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

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

[0112] The request to switch the physical downlink control channel from the first link to the second link may be transmitted via one of: user equipment assistance information, ascheduling request, an LI reference signal received power report, an LI measurement report, or channel state information.

[0113] The example apparatus may be further configured to: receive, from the network node via the first link, an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

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

[0115] The example apparatus may be further configured to: determine a delay for the switch of the physical downlink control channel from the first link to the second link based, at least partially, on the acknowledgement.

[0116] The acknowledgement may be received via the downlink control information indication, and the example apparatus may be further configured to: transmit, to the network node, a hybrid automatic repeat request acknowledgment in response to the downlink control information indication; and prepare to receive the physical downlink control channel via the second link at one of: a time of transmission of the hybrid automatic repeat request acknowledgment, or an expected time of reception of the hybrid automatic repeat request acknowledgment by the network node.

[0117] The acknowledgement may comprise a hybrid automatic repeat request acknowledgement.

[0118] The determined delay may be based, at least partially, on a time to receive the acknowledgment and a time to switch the physical downlink control channel.

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

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

[0121] The first link and the second link may be configured to carry a physical downlink shared channel.

[0122] The example method may further comprise: transmitting, to the network node, an indication of a capability to support physical downlink control channel link switching; and receiving, from the network node, a configuration to enable the physical downlink control channel link switching.

[0123] The example method may further comprise: monitoring the second link for the physical downlink control channel.

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

[0125] The determining to switch the physical downlink control channel from the first link to the second link may comprise: determining that a quality of the second link is higher than a quality of the first link; and determining to switch the physical downlink control channel from the first link to the second link in response to the quality of the second link being higher than the quality of the first link.

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

[0127] The request to switch the physical downlink control channel from the first link to the second link may be transmitted via one of: user equipment assistance information, a scheduling request, an LI reference signal received power report, an LI measurement report, or channel state information.

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

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

[0130] The example method may further comprise: determining a delay for the switch of the physical downlink control channel from the first link to the second link based, at least partially, on the acknowledgement.

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

[0132] The acknowledgement may comprise a hybrid automatic repeat request acknowledgement.

[0133] The determined delay may be based, at least partially, on a time to receive the acknowledgment and a time to switch the physical downlink control channel.

[0134] In accordance with one example embodiment, an apparatus may comprise: circuitry configured to perform: determining a quality of a first link with a first transmission point of a network node, wherein the first link may be configured to carry a physical downlink control channel; determining a quality of a second link with a second transmission point of thenetwork node; determining to switch the physical downlink control channel from the first link to the second link; and transmitting, to the network node, a request to switch the physical downlink control channel from the first link to the second link.

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

[0136] As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.” This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

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

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

[0139] The first link and the second link may be configured to carry a physical downlink shared channel.

[0140] The means may be further configured for: transmitting, to the network node, an indication of a capability to support physical downlink control channel link switching; and receiving, from the network node, a configuration to enable the physical downlink control channel link switching.

[0141] The means may be further configured for: monitoring the second link for the physical downlink control channel.

[0142] The means configured for determining to switch the physical downlink control channel from the first link to the second link may comprise means configured for: determining that a link quality of the second link exceeds a threshold; and determining to switch the physical downlink control channel from the first link to the second link in response to the link quality of the second link exceeding the threshold.

[0143] The means configured for determining to switch the physical downlink control channel from the first link to the second link may comprise means configured for: determining that a quality of the second link is higher than a quality of the first link; and determining to switch the physical downlink control channel from the first link to the second link in response to the quality of the second link being higher than the quality of the first link.

[0144] The means configured for determining to switch the physical downlink control channel from the first link to the second link may comprise means configured for: determining that a link quality of the first link is below a threshold; and determining to switch the physical downlink control channel from the first link to the second link in response to the link quality of the first link being below the threshold.

[0145] The request to switch the physical downlink control channel from the first link to the second link may be transmitted via one of: user equipment assistance information, a scheduling request, an LI reference signal received power report, an LI measurement report, or channel state information.

[0146] The means may be further configured for: receiving, from the network node via the first link, an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

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

[0148] The means may be further configured for: determining a delay for the switch of the physical downlink control channel from the first link to the second link based, at least partially, on the acknowledgement.

[0149] The acknowledgement may be received via the downlink control information indication, wherein the means may be further configured for: transmitting, to the network node, a hybrid automatic repeat request acknowledgment in response to the downlink control information indication; and preparing to receive the physical downlink control channel via the second link at one of: a time of transmission of the hybrid automatic repeat request acknowledgment, or an expected time of reception of the hybrid automatic repeat request acknowledgment by the network node.

[0150] The acknowledgement may comprise a hybrid automatic repeat request acknowledgement.

[0151] The determined delay may be based, at least partially, on a time to receive the acknowledgment and a time to switch the physical downlink control channel.

[0152] A processor, memory, and / or example algorithms (which may be encoded as instructions, program, or code) may be provided as example means for providing or causing performance of operation.

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

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

[0155] In accordance with another example embodiment, a non-transitory program storage device readable by a machine may be provided, tangibly embodying instructions executable by the machine for performing operations, the operations comprising: determining a quality of a first link with a first transmission point of a network node, wherein the first link may be configured to carry a physical downlink control channel; determining a quality of a second link with a second transmission point of the network node; determining to switch the physical downlink control channel from the first link to the second link; and causing transmitting, to the network node, of a request to switch the physical downlink control channel from the first link to the second link.

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

[0157] A computer implemented system comprising: 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 at least to perform: determining a quality of a first link with a first transmission point of a network node, wherein the first link may be configured to carry a physical downlink control channel; determining a quality of a second link with a second transmission point of the network node; determining to switch the physical downlink control channel from the first link to the second link; and causing transmitting, to the network node, of a request to switch the physical downlink control channel from the first link to the second link.

[0158] A computer implemented system comprising: means for determining a quality of a first link with a first transmission point of a network node, wherein the first link may be configured to carry a physical downlink control channel; means for determining a quality of a second link with a second transmission point of the network node; means for determining to switch the physical downlink control channel from the first link to the second link; and means for causing transmitting, to the network node, of a request to switch the physical downlink control channel from the first link to the second link.

[0159] In accordance with one example embodiment, an apparatus may comprise: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least 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, wherein the second link may be provided via a second transmission point; and transmit, to the user equipment, an acknowledgement ofthe request to switch the physical downlink control channel from the first link to the second link.

[0160] The first transmission point may comprise a first transmission and reception point, and the second transmission point may comprise a second transmission and reception point.

[0161] The first link and the second link may be configured to carry a physical downlink shared channel.

[0162] The example apparatus may be further configured to: receive, from the user equipment, an indication of a capability to support physical downlink control channel link switching; and transmit, to the user equipment, a configuration to enable the physical downlink control channel link switching.

[0163] The request to switch the physical downlink control channel from the first link to the second link may be received via one of: user equipment assistance information, a scheduling request, an LI reference signal received power report, an LI measurement report, or channel state information.

[0164] The acknowledgement may comprise an indication to switch the physical downlink control channel from the first link to the second link, wherein the acknowledgement may be transmitted via one of: a medium access control control element, a downlink control information indication, or a radio resource control reconfiguration message.

[0165] The acknowledgement may be transmitted via the downlink control information indication, and the example apparatus may be further configured to: receive, from the user equipment, a hybrid automatic repeat request acknowledgment in response to the downlink control information indication.

[0166] The acknowledgement may comprise a hybrid automatic repeat request acknowledgement.

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

[0168] The first transmission point may comprise a first transmission and reception point, and the second transmission point may comprise a second transmission and reception point.

[0169] The first link and the second link may be configured to carry a physical downlink shared channel.

[0170] The example method may further comprise: receiving, from the user equipment, an indication of a capability to support physical downlink control channel link switching; and transmitting, to the user equipment, a configuration to enable the physical downlink control channel link switching.

[0171] The request to switch the physical downlink control channel from the first link to the second link may be received via one of: user equipment assistance information, a scheduling request, an LI reference signal received power report, an LI measurement report, or channel state information.

[0172] The acknowledgement may comprise an indication to switch the physical downlink control channel from the first link to the second link, wherein the acknowledgement may be transmitted via one of: a medium access control control element, a downlink control information indication, or a radio resource control reconfiguration message.

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

[0174] The acknowledgement may comprise a hybrid automatic repeat request acknowledgement.

[0175] In accordance with one example embodiment, an apparatus may comprise: circuitry configured to perform: receiving, from a user equipment, a request to switch aphysical downlink control channel from a first link to a second link, wherein the first link may be provided via a first transmission point, wherein the second link may be provided via a second transmission point; and circuitry configured to perform: transmitting, to the user equipment, an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

[0176] In accordance with one example embodiment, an apparatus may comprise: processing circuitry; memory circuitry including computer program code, the memory circuitry and the computer program code configured to, with the processing circuitry, 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, wherein the second link may be provided via a second transmission point; and transmit, to the user equipment, an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

[0177] In accordance with one example embodiment, an apparatus may comprise means 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, wherein the second link may be provided via a second transmission point; and transmitting, to the user equipment, an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

[0178] The first transmission point may comprise a first transmission and reception point, and the second transmission point may comprise a second transmission and reception point.

[0179] The first link and the second link may be configured to carry a physical downlink shared channel.

[0180] The means may be further configured for: receiving, from the user equipment, an indication of a capability to support physical downlink control channel link switching; and transmitting, to the user equipment, a configuration to enable the physical downlink control channel link switching.

[0181] The request to switch the physical downlink control channel from the first link to the second link may be received via one of: user equipment assistance information, ascheduling request, an LI reference signal received power report, an LI measurement report, or channel state information.

[0182] The acknowledgement may comprise an indication to switch the physical downlink control channel from the first link to the second link, wherein the acknowledgement may be transmitted via one of: a medium access control control element, a downlink control information indication, or a radio resource control reconfiguration message.

[0183] The acknowledgement may be transmitted via the downlink control information indication, wherein the means may be further configured for: receiving, from the user equipment, a hybrid automatic repeat request acknowledgment in response to the downlink control information indication.

[0184] The acknowledgement may comprise a hybrid automatic repeat request acknowledgement.

[0185] In accordance with one example embodiment, a non-transitory computer-readable medium comprising instructions stored thereon which, when executed with at least one processor, cause the at least one processor to: cause receiving, from a user equipment, of 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, wherein the second link may be provided via a second transmission point; and cause transmitting, to the user equipment, of an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

[0186] In accordance with one example embodiment, a non-transitory computer-readable medium comprising program instructions stored thereon for performing at least the following: causing receiving, from a user equipment, of 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, wherein the second link may be provided via a second transmission point; and causing transmitting, to the user equipment, of an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

[0187] In accordance with another example embodiment, a non-transitory program storage device readable by a machine may be provided, tangibly embodying instructionsexecutable by the machine for performing operations, the operations comprising: causing receiving, from a user equipment, of 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, wherein the second link may be provided via a second transmission point; and causing transmitting, to the user equipment, of an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

[0188] In accordance with another example embodiment, a non-transitory computer- readable medium comprising instructions that, when executed by an apparatus, cause the apparatus to perform at least the following: causing receiving, from a user equipment, of 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, wherein the second link may be provided via a second transmission point; and causing transmitting, to the user equipment, of an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

[0189] A computer implemented system comprising: 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 at least to perform: causing receiving, from a user equipment, of 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, wherein the second link may be provided via a second transmission point; and causing transmitting, to the user equipment, of an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

[0190] A computer implemented system comprising: means for causing receiving, from a user equipment, of 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, wherein the second link may be provided via a second transmission point; and means for causing transmitting, to the user equipment, of an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

[0191] The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e. tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0192] It should be understood that the foregoing description is only illustrative. Various alternatives and modifications can be devised by those skilled in the art. For example, features recited in the various dependent claims could be combined with each other in any suitable combination(s). In addition, features from different embodiments described above could be selectively combined into a new embodiment. Accordingly, the description is intended to embrace all such alternatives, modification and variances which fall within the scope of the appended claims.

Claims

Claims:

1. A method comprising: determining, with a user equipment, a 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; determining a quality of a second link with a second transmission point of the network node; determining to switch the physical downlink control channel from the first link to the second link; and transmitting, to the network node, a request to switch the physical downlink control channel from the first link to the second link.

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

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

4. The method of any of claims 1 through 3, further comprising: transmitting, to the network node, an indication of a capability to support physical downlink control channel link switching; and receiving, from the network node, a configuration to enable the physical downlink control channel link switching.

5. The method of any of claims 1 through 4, further comprising: monitoring the second link for the physical downlink control channel.

6. The method of any of claims 1 through 5, wherein the determining to switch the physical downlink control channel from the first link to the second link comprises: determining that a link quality of the second link exceeds a threshold; and determining to switch the physical downlink control channel from the first link to the second link in response to the link quality of the second link exceeding the threshold.

7. The method of any of claims 1 through 5, wherein the determining to switch the physical downlink control channel from the first link to the second link comprises: determining that a quality of the second link is higher than a quality of the first link; and determining to switch the physical downlink control channel from the first link to the second link in response to the quality of the second link being higher than the quality of the first link.

8. The method of any of claims 1 through 5, wherein the determining to switch the physical downlink control channel from the first link to the second link comprises: determining that a link quality of the first link is below a threshold; and determining to switch the physical downlink control channel from the first link to the second link in response to the link quality of the first link being below the threshold.

9. The method of any of claims 1 through 8, wherein the request to switch the physical downlink control channel from the first link to the second link is transmitted via one of: user equipment assistance information, a scheduling request, an LI reference signal received power report, an LI measurement report, or channel state information.

10. The method of any of claims 1 through 9, further comprising: receiving, from the network node via the first link, an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

11. The method of claim 10, wherein the acknowledgement comprises an indication to switch the physical downlink control channel from the first link to the second link, wherein the acknowledgement is received via one of: a medium access control control element, a downlink control information indication, or a radio resource control reconfiguration message.

12. The method of claim 11, further comprising: determining a delay for the switch of the physical downlink control channel from the first link to the second link based, at least partially, on the acknowledgement.

13. The method of claim 11 , wherein the acknowledgement is received via the downlink control information indication, further comprising: transmitting, to the network node, a hybrid automatic repeat request acknowledgment in response to the downlink control information indication; and preparing to receive the physical downlink control channel via the second link at one of: a time of transmission of the hybrid automatic repeat request acknowledgment, or an expected time of reception of the hybrid automatic repeat request acknowledgment by the network node.

14. The method claim 12, wherein the acknowledgement comprises a hybrid automatic repeat request acknowledgement.

15. The method of claim 14, wherein the determined delay is based, at least partially, on a time to receive the acknowledgment and a time to switch the physical downlink control channel.

16. An apparatus comprising: at least one processor; and at least one non-transitory memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine a 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 a quality of a second link with a second transmission point of the network node; determine to switch the physical downlink control channel from the first link to the second link; and transmit, to the network node, a request 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 comprises a first transmission and reception point of the network node, and wherein the second transmission point of the network node comprises 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 of any of claims 16 through 18, wherein the at least one non- transitory memory storing instructions that, when executed by the at least one processor, cause the apparatus to: transmit, to the network node, an indication of a capability to support physical downlink control channel link switching; and receive, from the network node, a configuration to enable the physical downlink control channel link switching.

20. The apparatus of any of claims 16 through 19, wherein the at least one non- transitory memory storing instructions that, when executed by the at least one processor, cause the apparatus to: monitor the second link for the physical downlink control channel.

21. The apparatus of any of claims 16 through 20, wherein the determining to switch the physical downlink control channel from the first link to the second link comprises the at least one non-transitory memory storing instructions that, when executed by the at least one processor, cause the apparatus to: determine that a link quality of the second link exceeds a threshold; and determine to switch the physical downlink control channel from the first link to the second link in response to the link quality of the second link exceeding the threshold.

22. The apparatus of any of claims 16 through 20, wherein the determining to switch the physical downlink control channel from the first link to the second link comprises the at least one non-transitory memory storing instructions that, when executed by the at least one processor, cause the apparatus to: determine that a quality of the second link is higher than a quality of the first link; and determine to switch the physical downlink control channel from the first link to the second link in response to the quality of the second link being higher than the quality of the first link.

23. The apparatus of any of claims 16 through 20, wherein the determining to switch the physical downlink control channel from the first link to the second link comprises the at least one non-transitory memory storing instructions that, when executed by the at least one processor, cause the apparatus to: determine that a link quality of the first link is below a threshold; and determine to switch the physical downlink control channel from the first link to the second link in response to the link quality of the first link being below the threshold.

24. The apparatus of any of claims 16 through 23, wherein the request to switch the physical downlink control channel from the first link to the second link is transmitted via one of: user equipment assistance information, a scheduling request, an LI reference signal received power report, an LI measurement report, or channel state information.

25. The apparatus of any of claims 16 through 24, wherein the at least one non- transitory memory storing instructions that, when executed by the at least one processor, cause the apparatus to: receive, from the network node via the first link, an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

26. The apparatus of claim 25, wherein the acknowledgement comprises an indication to switch the physical downlink control channel from the first link to the second link, wherein the acknowledgement is received via one of: a medium access control control element, a downlink control information indication, or a radio resource control reconfiguration message.

27. The apparatus of claim 26, wherein the at least one non-transitory memory storing instructions that, when executed by the at least one processor, cause the apparatus to: determine a delay for the switch of the physical downlink control channel from the first link to the second link based, at least partially, on the acknowledgement.

28. The apparatus of claim 26, wherein the acknowledgement is received via the downlink control information indication, the at least one non-transitory memory storing instructions that, when executed by the at least one processor, cause the apparatus to: transmit, to the network node, a hybrid automatic repeat request acknowledgment in response to the downlink control information indication; and prepare to receive the physical downlink control channel via the second link at one of: a time of transmission of the hybrid automatic repeat request acknowledgment, or an expected time of reception of the hybrid automatic repeat request acknowledgment by the network node.

29. The apparatus claim 27, wherein the acknowledgement comprises a hybrid automatic repeat request acknowledgement.

30. The apparatus of claim 29, wherein the determined delay is based, at least partially, on a time to receive the acknowledgment and a time to switch the physical downlink control channel.

31. A method comprising: receiving, with a network node 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, wherein the second link is provided via a second transmission point; and transmitting, to the user equipment, an acknowledgement 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 comprises a first transmission and reception point, and wherein the second transmission point comprises 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 of any of claims 31 through 33, further comprising: receiving, from the user equipment, an indication of a capability to support physical downlink control channel link switching; and transmitting, to the user equipment, a configuration to enable the physical downlink control channel link switching.

35. The method of any of claims 31 through 34, wherein the request to switch the physical downlink control channel from the first link to the second link is received via one of: user equipment assistance information, a scheduling request, an LI reference signal received power report, an LI measurement report, or channel state information.

36. The method of any of claims 31 through 35, wherein the acknowledgement comprises an indication to switch the physical downlink control channel from the first link to the second link, wherein the acknowledgement is transmitted via one of: a medium access control control element, a downlink control information indication, or a radio resource control reconfiguration message.

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

38. An apparatus comprising: at least one processor; and at least one non-transitory memory storing instructions that, when executed by the at least one processor, cause the apparatus at least 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 is provided via a first transmission point, wherein the second link is provided via a second transmission point; and transmit, to the user equipment, an acknowledgement 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 comprises a first transmission and reception point, and wherein the second transmission point comprises 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 of any of claims 38 through 40, wherein the at least one non- transitory memory storing instructions that, when executed by the at least one processor, cause the apparatus to: receive, from the user equipment, an indication of a capability to support physical downlink control channel link switching; and transmit, to the user equipment, a configuration to enable the physical downlink control channel link switching.

42. The apparatus of any of claims 38 through 41, wherein the request to switch the physical downlink control channel from the first link to the second link is received via one of: user equipment assistance information,a scheduling request, an LI reference signal received power report, an LI measurement report, or channel state information.

43. The apparatus of any of claims 38 through 42, wherein the acknowledgement comprises an indication to switch the physical downlink control channel from the first link to the second link, wherein the acknowledgement is transmitted via one of: a medium access control control element, a downlink control information indication, or a radio resource control reconfiguration message.

44. The apparatus of claim 43, wherein the acknowledgement is transmitted via the downlink control information indication, the at least one non-transitory memory storing instructions that, when executed by the at least one processor, cause the apparatus to: receive, from the user equipment, a hybrid automatic repeat request acknowledgment in response to the downlink control information indication.

45. An apparatus comprising means for: determining a 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; determining a quality of a second link with a second transmission point of the network node; determining to switch the physical downlink control channel from the first link to the second link; and transmitting, to the network node, a request to switch the physical downlink control channel from the first link to the second link.

46. An apparatus comprising means 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, wherein the second link is provided via a second transmission point; and transmitting, to the user equipment, an acknowledgement of the request to switch the physical downlink control channel from the first link to the second link.

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