PATENT DOCUMENT

Publication Number: US-12052085-B2
Application Number: US-202017438202-A
Country: US
Kind Code: B2

Title: Systems and methods for beam failure recovery for multi-DCI mode

Abstract:
Beam failure recovery (BFR) in a multiple Downlink Control Information (mDCI) mode may include receiving, by a user equipment (UE), a Downlink Reference Signal (DL RS) set from a next generation Node B (gNB). The DL RS set may be associated with a link between the UE and the gNB and indicate beam failure detection (BFD) is to be performed for the link. The BFR may further include performing, by the UE, a beam failure detection (BFD) for the link using the DL RS set, and performing, by the UE, a candidate beam detection (CBD) for the link, the CBD determining a candidate beam for the link by determining a beam having a reference signal receiving power (RSRP) that is larger than an RSRP threshold. The BFR may further include transmitting, by the UE, a beam failure recovery request (BFRQ) indicating the link to the gNB.

Claims:
What is claimed is: 
     
       1. A non-transitory computer-readable storage medium for a user equipment (UE) to perform beam failure recovery (BFR) in a multiple Downlink Control Information (mDCI) mode, the non-transitory computer-readable storage medium including instructions that when executed by a computer, cause the computer to:
 receive, by the UE, a Downlink Reference Signal (DL RS) set from a next generation Node B (gNB), the DL RS set associated with a link between the UE and the gNB and indicating beam failure detection (BFD) is to be performed for the link, the DL RS set received periodically by the UE from the gNB, wherein the DL RS set corresponds to one or more CORESETs having a same CORESET-poolIndex value; 
 perform, by the UE, a beam failure detection (BFD) for the link using the DL RS set, the BFD determining a beam failure for the link by determining that a block error ratio (BLER) for the link is larger than a BLER threshold; 
 perform, by the UE, a candidate beam detection (CBD) for the link, the CBD determining a candidate beam for the link by determining a beam having a reference signal receiving power (RSRP) that is larger than an RSRP threshold; and 
 transmit, by the UE, a beam failure recovery request (BFRQ) indicating the link to the gNB. 
 
     
     
       2. The non-transitory computer readable storage medium of  claim 1 , wherein the DL RS set includes a DL RS that is a Channel State Information Reference Signal (CSI-RS) or a synchronization signal block (SSB) indicating BFD is to be performed for the link. 
     
     
       3. The non-transitory computer readable storage medium of  claim 2 , wherein the DL RS is configured by radio resource control (RRC) signaling. 
     
     
       4. The non-transitory computer readable storage medium of  claim 1 , wherein the non-transitory computer-readable storage medium includes instructions that cause the computer to:
 receive, by the UE, an additional DL RS set from the gNB, the additional DL RS set associated with the link and configuring the UE for the CBD, the additional DL RS set received periodically by the UE from the gNB. 
 
     
     
       5. The non-transitory computer readable storage medium of  claim 4 , wherein the additional DL RS set corresponds to one or more CORESETs having the same CORESET-poolIndex value. 
     
     
       6. The non-transitory computer readable storage medium of  claim 4 , wherein the additional DL RS set includes a DL RS that is a CSI-RS or a SSB indicating CBD is to be performed for the link. 
     
     
       7. The non-transitory computer readable storage medium of  claim 6 , wherein the non-transitory computer-readable storage medium includes instructions that cause the computer to:
 determine, by the UE, that the DL RS of the additional DL RS set is not configured by a gNB; and 
 use, by the UE, a default DL RS, wherein the default DL RS is an SSB from an initial bandwidth part or a current bandwidth part and indicates CBD for the link. 
 
     
     
       8. The non-transitory computer readable storage medium of  claim 1 , wherein the BFRQ is transmitted via a Media Access Control Control Element (MAC CE) that includes a failed CORESET-poolIndex or DL RS set index corresponding to the link. 
     
     
       9. The non-transitory computer readable storage medium of  claim 1 , wherein the BFRQ is transmitted using a physical random access channel (PRACH), wherein the UE is configured with a PRACH resource associated with a DL RS for the CBD of the link, the PRACH resource belonging to a group of resources for the same CORESET-poolIndex value. 
     
     
       10. The non-transitory computer readable storage medium of  claim 1 , wherein the BFRQ is transmitted using multi-bit PUCCH resources, wherein each PUCCH resource of the PUCCH resources is associated with the same CORESET-poolIndex value, and wherein each PUCCH resource includes a failed CORESET-poolIndex or DL RS set index corresponding to the link. 
     
     
       11. The non-transitory computer readable storage medium of  claim 1 , wherein the non-transitory computer-readable storage medium includes instructions that cause the computer to:
 receive, by the UE, a response regarding the BFRQ from the gNB; and 
 apply, by the UE, the candidate beam to one or more CORESETs corresponding to a failed CORESET-poolIndex or DL RS set index corresponding to the link. 
 
     
     
       12. The non-transitory computer readable storage medium of  claim 1 , wherein the BFD and the CBD are performed sequentially. 
     
     
       13. The non-transitory computer readable storage medium of  claim 1 , wherein the BFD and the CBD are performed simultaneously. 
     
     
       14. The non-transitory computer readable storage medium of  claim 1 , wherein the non-transitory computer-readable storage medium includes instructions that cause the computer to:
 receive, at the UE, control signaling from the gNB that enables multi-DCI BFR. 
 
     
     
       15. The non-transitory computer readable storage medium of  claim 14 , wherein the control signaling is RRC signaling. 
     
     
       16. The non-transitory computer readable storage medium of  claim 14 , wherein the control signaling includes a plurality of DL RS sets configured for BFR and wherein the non-transitory computer-readable storage medium includes instructions that cause the computer to:
 determine multi-DCI BFR is enabled due to the presence of the plurality of DL RS sets configured for BFR. 
 
     
     
       17. A method for beam failure recovery (BFR) in a multiple Downlink Control Information (mDCI) mode, the method comprising:
 receiving, by a UE, a Downlink Reference Signal (DL RS) set from a next generation Node B (gNB), the DL RS set associated with a link between the UE and the gNB and indicating beam failure detection (BFD) is to be performed for the link, the DL RS set received periodically by the UE from the gNB, wherein the DL RS set corresponds to one or more CORESETs having a same CORESET-poolIndex value; 
 performing, by the UE, a beam failure detection (BFD) for the link using the DL RS set, the BFD determining a beam failure for the link by determining that a block error ratio (BLER) for the link is larger than a BLER threshold; 
 performing, by the UE, a candidate beam detection (CBD) for the link, the CBD determining a candidate beam for the link by determining a beam having a reference signal receiving power (RSRP) that is larger than an RSRP threshold; and 
 transmitting, by the UE, a beam failure recovery request (BFRQ) indicating the link to the gNB. 
 
     
     
       18. An apparatus for a user equipment (UE) to perform beam failure recovery (BFR) in a multiple Downlink Control Information (mDCI) mode, the apparatus comprising:
 a processor; and 
 a memory storing instructions that, when executed by the processor, configure the apparatus to: 
 receive, by the UE, a Downlink Reference Signal (DL RS) set from a next generation Node B (gNB), the DL RS set associated with a link between the UE and the gNB and indicating beam failure detection (BFD) is to be performed for the link, the DL RS set received periodically by the UE from the gNB, wherein the DL RS set corresponds to one or more CORESETs having a same CORESET-poolIndex value; 
 perform, by the UE, a beam failure detection (BFD) for the link using the DL RS set, the BFD determining a beam failure for the link by determining that a block error ratio (BLER) for the link is larger than a BLER threshold; 
 perform, by the UE, a candidate beam detection (CBD) for the link, the CBD determining a candidate beam for the link by determining a beam having a reference signal receiving power (RSRP) that is larger than an RSRP threshold; and 
 transmit, by the UE, a beam failure recovery request (BFRQ) indicating the link to the gNB.

Description:
TECHNICAL FIELD 
     This application relates generally to wireless communication systems. 
     BACKGROUND 
     Wireless mobile communication technology uses various standards and protocols to transmit data between a base station and a wireless mobile device. Wireless communication system standards and protocols can include the 3rd Generation Partnership Project (3GPP) long term evolution (LTE) (e.g., 4G) or new radio (NR) (e.g., 5G); the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard, which is commonly known to industry groups as worldwide interoperability for microwave access (WiMAX); and the IEEE 802.11 standard for wireless local area networks (WLAN), which is commonly known to industry groups as Wi-Fi. In 3GPP radio access networks (RANs) in LTE systems, the base station can include a RAN Node such as a Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (also commonly denoted as evolved Node B, enhanced Node B, eNodeB, or eNB) and/or Radio Network Controller (RNC) in an E-UTRAN, which communicate with a wireless communication device, known as user equipment (UE). In fifth generation (5G) wireless RANs, RAN Nodes can include a 5G Node, NR node (also referred to as a next generation Node B or g Node B (gNB)). 
     RANs use a radio access technology (RAT) to communicate between the RAN Node and UE. RANs can include global system for mobile communications (GSM), enhanced data rates for GSM evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), and/or E-UTRAN, which provide access to communication services through a core network. Each of the RANs operates according to a specific 3GPP RAT. For example, the GERAN implements GSM and/or EDGE RAT, the UTRAN implements universal mobile telecommunication system (UMTS) RAT or other 3GPP RAT, the E-UTRAN implements LTE RAT, and NG-RAN implements 5G RAT. In certain deployments, the E-UTRAN may also implement 5G RAT. 
     Frequency bands for 5G NR may be separated into two different frequency ranges. Frequency Range 1 (FR1) includes sub-6 GHz frequency bands, some of which are bands that may be used by previous standards, but may potentially be extended to cover potential new spectrum offerings from 410 MHz to 7125 MHz. Frequency Range 2 (FR2) includes frequency bands from 24.25 GHz to 52.6 GHz. Bands in the millimeter wave (mmWave) range of FR2 have shorter range but higher available bandwidth than bands in the FR1. Skilled persons will recognize these frequency ranges, which are provided by way of example, may change from time to time or from region to region. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced. 
         FIG.  1    illustrates a system in accordance with some embodiments. 
         FIG.  2    illustrates a process in accordance with some embodiments. 
         FIG.  3    illustrates a diagram in accordance with some embodiments. 
         FIG.  4    illustrates a diagram in accordance with some embodiments. 
         FIG.  5    illustrates a system in accordance with some embodiments. 
         FIG.  6    illustrates a device in accordance with some embodiments. 
         FIG.  7    illustrates example interfaces in accordance with some embodiments. 
         FIG.  8    illustrates components in accordance with some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     In 3GPP Rel-16, operation using multiple Downlink Control Information (mDCI) mode based multiple transmission and reception points (multi-TRP) has been supported. Here, a UE can receive signals from multiple TRPs simultaneously, which are scheduled by multiple Physical Downlink Control Channels (PDCCHs). PDCCHs from different TRPs can be transmitted from different Control Resource Sets (CORESETs) with different CORESET-poolIndex values. The network may be deployed with an ideal-backhaul or non-ideal-backhaul. 
     In 3GPP Rel-15/Rel-16, the beam failure recovery (BFR) operation has been supported. A UE can report to a next generation NodeB (gNB) that the beams for all the CORESETs in a serving cell failed, and further report a new candidate beam to the gNB. The UE can determine a hypothetical block error ratio (BLER) for a downlink reference signal, e.g. a Channel State Information Reference Signal (CSI-RS), which is quasi-co-located (QCLed) with a CORESET to determine whether the beam for the CORESET fails or not. If the detected BLER is larger than a threshold, the UE can determine a beam failure instance for a CORESET. After detecting X number of consecutive beam failure instances for all CORESETs, the UE can declare beam failure. The new candidate beam can be the beam having a reference signal receiving power (RSRP) that is larger than a threshold. 
     For mDCI mode, gNB(s) can be deployed in non-ideal-backhaul mode. However, 3GPP Rel-15/Rel-16 behavior may not recover beam failure between one gNB to a UE. This is because the UE reports beam failure and a potential new candidate beam only after beam failure happens for all CORESETs. Thus, determining how to perform beam failure recovery (BFR) between a gNB and UE may be an issue. More specifically, issues may include how to detect the beam failure between a gNB and UE, how to detect the new candidate beam (e.g., candidate beam detection, CBD) between a gNB and UE, and how to report the beam failure event (beam failure recovery request, BFRQ) when beam failure is declared. Some embodiments of the present disclosure may address one or more of such issues. 
     Solution—Procedure 
     In some embodiments, a beam failure recovery (BFR) procedure may be performed per link. Each link may be a link between a gNB and a UE. In some embodiments, the UE performs beam failure detection (BFD) and CBD simultaneously. In other embodiments, the UE performs BFD first and after it declares beam failure, the UE performs CBD. 
     Solution—Beam Failure Detection 
     In some embodiments, in multi-DCI mode, a UE can detect BFD based on N number, e.g. N=2, sets of downlink reference signals (DL RSs). In some embodiments, each set of DL RS may correspond to CORESETs with the same CORESET-poolIndex. In some embodiments, the DL RS could be a CSI-RS and/or a synchronization signal block (SSB). In some embodiments, the DL RS can be configured by radio resource control (RRC) signaling. In some embodiments, if the DL RS is not configured (e.g., not configured by RRC signaling), the DL RS configured for a transmission configuration indicator (TCI) state for a CORESET could be used for beam failure detection. Here, for example, if there are two DL RS configured in a TCI state, the one configured with QCL-typeD (e.g., spatial receiver (Rx) parameters) can be used. In some embodiments, the DLRS can be QCLed with a CORESET. In some embodiments, the BLER threshold and other BFD related parameters, e.g. BFD counter/timer, could be the same or different for each set. 
     Solution—Candidate Beam Detection 
     In some embodiments, in multi-DCI mode, a UE can be configured with N number, e.g. N=2, sets of downlink reference signals for candidate beam detection. In some embodiments, each set of DL RS may correspond to BFR for CORESETs with the same CORESET-poolIndex. In some embodiments, the DL RS could be CSI-RS and/or SSB. In some embodiments, the DL RS can be configured by RRC signaling. Here, for example, the gNB may configure at least one DL RS for a set. In some embodiments, if a DL RS is not configured for a set, a default DL RS set can be used, e.g. the SSB from initial bandwidth part. In some embodiments, the N sets of DL RS for candidate beam detection may be orthogonal. In some embodiments, the RSRP threshold could be the same or different for each sets. 
     Solution—Beam Failure Recovery Request 
     In some embodiments, after a UE declares that beam failure happens for a set of DL RS for BFD, the UE can report a beam failure recovery request (BFRQ) e.g., to a gNB. In some embodiments, the BFRQ can be reported by a medium access control (MAC) control element (CE) (Option 1). In some embodiments, the BFRQ can be reported by a physical random access channel (PRACH) (Option 2). In some embodiments, the BFRQ can be reported by physical uplink control channel (PUCCH) (Option 3). In some embodiments, for each option, after K number (e.g., K=28) of symbols after the UE receives a response from the gNB, the UE can apply the new beam to all the CORESETs corresponding to the failed CORESET-poolIndex or the UE can apply the new beam to all the PUCCH resources corresponding to the failed CORESET-poolIndex if no BFRQ related signal is transmitted from the PUCCH resource. 
     Solution—Option 1 
     In some embodiments, the MAC CE can carry the BFRQ and can include one of, a subset of, or all of the following information: failed serving cell index; failed CORESET-poolIndex or DL RS set index for BFD; a flag to indicate whether a new beam is detected; a new beam index selected from corresponding DL RS set for CBD. In some embodiments, one MAC CE can be used to indicate beam failure for one or multiple serving cells. In another example, one MAC CE can be used to indicate beam failure for one or multiple CORESET-poolIndex in one serving cell. In another example, one MAC CE can be used to indicate beam failure for one CORESET-poolIndex in one serving cell. In some embodiments, regarding the priority of MAC CE multiplexing, the priority of the MAC CE could be the same as the priority of MAC CE for BFR in 3GPP Rel-16. In another example, the priority of the MAC CE could be lower or higher than MAC CE for BFR in 3GPP Rel-16. In some embodiments, the MAC CE may be triggered by a dedicated scheduling request which may be configured by higher layer signaling. In some embodiments, a response for the MAC CE could be a DCI to schedule a new transmission with the same hybrid automatic repeat request (HARM) process ID as the physical uplink shared channel (PUSCH) used to carry the MAC CE. 
     Solution—Option 2 
     In some embodiments, a UE can be configured with multiple PRACH resources, with each PRACH resource associated with a DL RS for CBD. In some embodiments, the PRACH resources could be divided into N number of groups. For example, each group can be used for BFRQ for a CORESET-poolIndex. In some embodiments, the response for the PRACH could be a PDCCH transmitted in a dedicated search space (SS) or CORESET. In some embodiments, the dedicated SS or CORESET could be configured by higher layer signaling, e.g. RRC signaling. 
     Solution—Option 3 
     In some embodiments, a UE can be configured by single-bit PUCCH resources, where each PUCCH resource is associated with a DL RS for CBD. In some embodiments, the PUCCH resources could be divided into N number of groups. For example, each group could be used for BFRQ for a CORESET-poolIndex. 
     In some embodiments, a UE can be configured by multi-bit PUCCH resources, where each PUCCH resource is associated with a CORESET-poolIndex. In some embodiments, the PUCCH can be used to carry one of, a subset of, or all of the following information: failed serving cell index; failed CORESET-poolIndex or DL RS set index for BFD; a flag to indicate whether a new beam is detected; a new beam index selected from corresponding DL RS set for CBD. In some embodiments, the response for the PUCCH could be a PDCCH transmitted in a dedicated search space (SS) or CORESET. In some embodiments, the dedicated SS or CORESET could be configured by higher layer signaling, e.g. RRC signaling. 
     Solution—Control signaling to enable multi-DCI BFR 
     In some embodiments, the multi-DCI BFR can be enabled by explicit RRC signaling. 
     In some embodiments, the multi-DCI BFR can be enabled by number of DL RS sets for BFD. In some embodiments, if more than one sets are configured, multi-DCI based BFR can be enabled. In some embodiments, if only one set is configured, 3GPP Rel-15/Rel-16 based BFR can be enabled. In some embodiments, if no set is configured, BFR can be disabled. 
     In some embodiments, to determine whether a set is configured, the UE can detect whether beamFailureDetectionCounter is configured or not. For example, if beamFailureDetectionCounter is configured, the UE can determine that the set is configured. 
     Otherwise, for example, if beamFailureDetectionCounter is not configured, the UE can determine that the set is not configured. 
       FIG.  1    shows a system  100  in accordance with some embodiments. In the embodiment shown, system  100  includes a gNB  102 , a gNB  104 , and a UE  106 . UE  106  and one or both of gNB  102  and gNB  104  may communicate with other using signals  108 , signals  112 , signals  116 , and signals  120 . For example, gNB  102  and/or gNB  104  are transmission and reception points (TRPs) in system  100 , and UE  106  supports multi-TRP operation. In some embodiments, gNB  102  transmits a signal  110  of signals  108  to UE  106  and UE  106  transmits a signal  114  of signals  112  to gNB  102 . In some embodiments, gNB  104  transmits a signal  122  of signals  120  to UE  106  and UE  106  transmits a signal  118  of signals  116  to gNB  104 . 
     In 3GPP Rel-16, multiple Downlink Control Information (mDCI) mode based multiple transmission and reception points (multi-TRP) operation has been supported. For example, UE  106  receives signals (e.g., signal  110  and signal  122  from multiple TRPs (e.g., gNB  102  and gNB  104 ) simultaneously, where the signal  110  and signal  122  are scheduled by multiple Physical Downlink Control channels (PDCCHs). PDCCHs from different TRPs (e.g., gNB  102 , gNB  104 ) can be transmitted from different Control Resource Sets (CORESETs) for each of the TRPs having different CORESET-poolIndex values. In some embodiments, signal  110  and/or signal  114  for communication between UE  106  and gNB  102  use a PDCCH from CORESET  1  having a CORESET-poolIndex value of zero. In some embodiments, signal  118  and/or signal  122  for communication between UE  106  and gNB  104  use a PDCCH from CORESET  2  having a CORESET-poolIndex value of one. In some embodiments, the network of system  100  (e.g., gNB  102  and gNB  104 ) having an mDCI mode may be deployed with an ideal-backhaul or non-ideal-backhaul. For example, a system with ideal-backhaul may have a latency less than at or about 2.5 microseconds and a throughput of up to at or about 10 Gbps. A system with non-ideal-backhaul may have a latency and throughout outside the ranges provided for ideal-backhaul. 
     In 3GPP Rel-15/Rel-16, beam failure recovery (BFR) operation has been supported. A UE (e.g., UE  106 ) may report the beams (or signals) for all the CORESETs in a serving cell failed, and report a new candidate beam to a next generation NodeB (gNB). UE  106  determines a hypothetical block error ratio (BLER) for a downlink reference signal, (e.g. Channel State Information Reference Signal (CSI-RS)), which is quasi-co-located (QCLed) with a CORESET to determine whether the beam for the CORESET fails or not. If the detected BLER is larger than a threshold, UE  106  can consider beam failure instance for a CORESET. After detecting X number of consecutive beam failure instances for all CORESETs, UE  106  can declare beam failure. The new candidate beam can be the beam having a reference signal receiving power (RSRP) that is larger than a threshold. 
     In some embodiments, BFR operation is performed using an alternative method. Here, determining that beams for all CORESETs in a serving cell failed is not required. Instead, a beam failure instance can be determined by a UE (e.g., UE  106 ) by determining that a beam for only a single CORESET for a gNB (e.g., gNB  102 , gNB  104 ) failed. Such BFR operation may allow improved link recovery that would otherwise be blocked if determining all beams for all CORESETs in a serving cell failed were required. 
       FIG.  2    shows a beam failure recovery (BFR) process  200  in accordance with some embodiments. In the embodiment shown, BFR process  200  is performed on a per link basis between a UE  202  (e.g., UE  106  in  FIG.  1   ) and a gNB  204  (e.g., gNB  102 , gNB  104  in  FIG.  1   ). It should be noted that the order of items shown in process  200  may be different to that shown in  FIG.  2    and item(s) may be combined and/or removed where suitable. 
     At item  206 , UE  202  receives control signaling for BFR from gNB  204 . In some embodiments, the control signaling is control signaling to enable multi-DCI BFR. In some embodiments, the control signaling can be explicit RRC signaling that enables multi-DCI BFR (e.g., link specific BFD and/or CBD is enabled). In some embodiments, the control signaling can be signaling by a number of downlink reference signals (DL RS) sets for BFD (or, e.g., CBD) that enable multi-DCI BFR. Here, if more than one (e.g., two or more) DL RS sets are configured by gNB  204  for BFD, UE  202  determines that multi-DCI based BFR (e.g., including BFD and/or CBD) is enabled per link (e.g., per link associated with each DL RS set). If only one set is configured, UE  202  determines that 3GPP Rel-15/Rel-16 based BFR is enabled. If no set is configured, UE  202  determines that BFR is disabled. In some embodiments, to determine whether a set (e.g., DL RS set) is configured, UE  202  detects whether beamFailureDetectionCounter is configured or not. For example, if beamFailureDetectionCounter is configured, UE  202  determines that the set (e.g., DL RS set) is configured. Otherwise, for example, if beamFailureDetectionCounter is not configured, UE  202  determines that the set (e.g., DL RS set) is not configured. 
     If multi-DCI BFR is configured, process  200  continues to item  208 . At item  208 , UE  202  receives from gNB  204  DL RS for beam failure detection (BFD) and/or candidate beam detection (CBD) for one or more links between UE  202  and gNB  204 . In some embodiments, one or more DL RS sets each containing one or more DL RS are received by UE  202  from gNB  204  per link between UE  202  and gNB  204 , where each DL RS set corresponds to a link between UE  202  and gNB  204 , and each DL RS within each DL RS set is for a particular beam within the link. In some embodiments, the transmission at item  208  is periodically sent by gNB  204  to UE  202  and periodically received by UE  202 . Process  200  then continues to item  210 , where BFD and/or CBD is performed on a per link basis by UE  202  depending on the DL RS of the link. Thus, one or multiple instances of BFD and/or CBD may be performed at item  210  depending on the number of link(s) that are present. 
     In some embodiments, the DL RS of item  208  is for BFD. In some embodiments, in multi-DCI mode, UE  202  detects BFD based on N number (e.g. N=2) of sets of DL RSs. UE  202  determines, for example, that N sets of DL RS have been configured (e.g., by gNB  204 ) for BFD and therefore indicate BFD is to be performed. In some embodiments, each set of DL RS may correspond to one or more CORESETs with the same CORESET-poolIndex. In some embodiments, a DL RS (e.g., of the DL RS set) could be a CSI-RS and/or a synchronization signal block (SSB) that indicates BFD is to be performed for a link. In some embodiments, a DL RS can be configured by radio resource control (RRC) signaling (e.g., by gNB  204 ). In some embodiments, if a DL RS is not configured (e.g., not configured by RRC signaling or configured as a CSI-RS or SSB), a DL RS configured for a transmission configuration indicator (TCI) state for a CORESET (e.g., for each CORESET having the same CORESET-poolIndex) could be used for beam failure detection. Here, for example, if there are two DL RS configured in a TCI state, the one configured with QCL-typeD (e.g., spatial receiver (Rx) parameters) can be used. In some embodiments, the DLRS can be QCLed with a CORESET. In some embodiments, the BLER threshold and other BFD related parameters, e.g. BFD counter/timer, could be the same or different for each set. In item  210 , BFD is performed for UE  202  since the DL RS of the link is for BFD. UE  202  can determine a BLER for a DL RS, which may be quasi-co-located (QCLed) with a CORESET, to determine whether the beam for the CORESET of a particular link fails or not. If the detected BLER is larger than a threshold, UE  202  can determine beam failure instance for a CORESET for the link. 
       FIG.  3    shows an exemplary diagram  300  illustrating the relation between DL RS and CORSET-poolIndex for BFD according to some embodiments. DL RS set  302  corresponds to CORESETS having a CORESET-poolIndex equal to zero for BFD, where DL RS set  302  includes a DL RS in a CSI-RS  304  and a DL RS in a CSI-RS  306 . DL RS set  308  corresponds to CORESETS having a CORESET-poolIndex equal to one for BFD, where DL RS set  308  includes a DL RS in a CSI-RS  310  and a DL RS in a CSI-RS  312 . 
     Back to  FIG.  2   , in some embodiments, DL RS of item  208  is for CBD. Here, in multi-DCI mode, UE  202  is configured with N number, e.g. N=2, sets of DL RS for CBD. UE  202  is thereby configured for CBD. In some embodiments, each set of DL RS is configured for CBD (e.g., by gNB  204 ). In some embodiments, each set of DL RS may correspond to one or more CORESETs with the same CORESET-poolIndex, for BFR. In some embodiments, a DL RS (e.g., of the DL RS set) could be a CSI-RS and/or SSB indicating CBD is to be performed for the link. In some embodiments, the DL RS can be configured by RRC signaling. Here, for example, the gNB may configure at least one DL RS for a set. In some embodiments, if UE  202  determines that a DL RS is not configured for a set (or that a DL RS set is not configured), a default DL RS or DL RS set can be used which, for example, may indicate CBD is to be performed for a link. The default DL RS or DL RS set can be, for example, an SSB from an initial bandwidth part (e.g., initial bandwidth used by UE  202  to access gNB  204 ) or SSB from the current bandwidth part (e.g., current bandwidth used by UE  202  to access gNB  204 ). In some embodiments, the N sets of DL RS for CBD may be orthogonal. In some embodiments, the RSRP threshold are the same or different for each sets. In item  210 , is CBD is performed by UE  202  since the DL RS of the link is for CBD and UE  202  is configured for CBD. The new candidate beam determined by CBD can be a beam having a reference signal receiving power (RSRP) that is larger than the RSRP threshold. 
       FIG.  4    shows an exemplary diagram  400  illustrating the relation between DLRS and CORSET-poolIndex for CBD according to some embodiments. DL RS set  402  corresponds to CORESETS having a CORESET-poolIndex equal to zero for CBD, where DL RS set  402  includes a DL RS in a CSI-RS  404 , a DL RS set in an SSB  406 , and a DL RS in other format(s)  408 . DL RS set  410  corresponds to CORESETS having a CORESET-poolIndex equal to one for CBD, where DL RS set  410  includes a DL RS in an SSB  412 , a DL RS in an SSB  414 , and a DL RS in other format(s)  416 . 
     Back to  FIG.  2   , at item  212 , UE  202  receives from gNB  204  DL RS (e.g., DL RS set; e.g., on a per link basis). In some embodiments, the DL RS set is for BFD. In some embodiments, the DL RS set is for CBD. In some embodiments, the DL RS set is for the other of BFD or CBD for each link which was not received at item  208 , by UE  202 . In some embodiments, the transmission at item  212  is periodically sent by gNB  204  to UE  202  and periodically received by UE  202 . Description regarding item  212  is the same or substantially the same as the description for item  208  and is therefore not repeated for brevity. At item  214 , BFD or CBD, depending on the DL RS transmitted at item  212 , is performed by UE  202  on a per link basis. Thus, one or multiple instances of BFD and/or CBD may be performed at item  210  depending on the number of link(s) that are present. For each link, if the DL RS of item  212  is for BFD, then BFD is performed by UE  202  at item  214 , and if the DL RS of item  212  is for CBD, then CBD is performed by UE  202  at item  214 . 
     It should be noted that in some embodiments, UE  202  performs BFD and CBD simultaneously for one or more links at item  210  and/or item  214  where item  208  and/or item  212  for the one or more links includes DL RS for BFD and CBD. 
     In some embodiments, UE  202  performs BFD and CBD sequentially. In some embodiments, BFD at item  210 , where item  208  includes DL RS for BFD. Process  200  then continues to item  216  to declare beam failure (if such failure is determined). Process  200  thereafter continues to perform CBD, receiving DL RS for CBD after item  216  or at some other time before performing CBD. 
     At item  216 , beam failure is declared using the detection of beam failure at item  210  or item  216 . 
     At item  218 , UE  202  transmits signaling to gNB  204 . In some embodiments, after UE  202  declares that beam failure occurs for a set of DL RS for BFD, UE  202  reports a beam failure recovery request (BFRQ) in the signaling to gNB  204 . 
     In some embodiments, the BFRQ is reported by UE  202  by a medium access control (MAC) control element (CE) (Option 1). Here, the MAC CE carries the BFRQ and can include one of, a subset of, or all of the following information: failed serving cell index; failed CORESET-poolIndex or DL RS set index for BFD; a flag to indicate whether a new beam is detected; a new beam index selected from corresponding DL RS set for CBD. In some embodiments, one MAC CE can be used to indicate beam failure for one or multiple serving cells. In some embodiments, one MAC CE can be used to indicate beam failure for one or multiple CORESET-poolIndex in one serving cell. In some embodiments, one MAC CE can be used to indicate beam failure for 1 CORESET-poolIndex in one serving cell. 
     Regarding the priority of MAC CE multiplexing, in some embodiments the priority of the MAC CE is the same as the priority of MAC CE for BFR in 3GPP Rel-16. In some embodiments, the priority of the MAC CE is lower or higher than MAC CE for BFR in 3GPP Rel-16. In some embodiments, the MAC CE is triggered by a dedicated scheduling request which is configured by higher layer signaling. In some embodiments, the response for the MAC CE could be a DCI to schedule a new transmission with the same hybrid automatic repeat request (HARM) process ID as the physical uplink shared channel (PUSCH) used to carry the MAC CE. 
     In some embodiments, the BFRQ is reported by UE  202  by a physical random access channel (PRACH) (Option 2). For example, UE  202  can be configured with multiple PRACH resources, with each PRACH resource associated with a DL RS for CBD. In some embodiments, the PRACH resources could be divided into N number of groups. For example, each group can be used for BFRQ for a CORESET-poolIndex. In some embodiments, a PRACH resource may belong to a group of PRACH resources for the same CORESET-poolIndex. In some embodiments, the response for the PRACH could be a PDCCH transmitted in a dedicated search space (SS) or CORESET. In some embodiments, the dedicated SS or CORESET could be configured by higher layer signaling, e.g. RRC signaling. 
     In some embodiments, the BFRQ is reported by UE  202  by physical uplink control channel (PUCCH) (Option 3). For example, UE  202  can be configured by single-bit PUCCH resources, where each PUCCH resource is associated with a DL RS for CBD. In some embodiments, the PUCCH resources could be divided into N number of groups. For example, each group could be used for BFRQ for a CORESET-poolIndex. 
     In some embodiments, UE  202  can be configured by multi-bit PUCCH resources, where each PUCCH resource is associated with a CORESET-poolIndex (e.g., the same index for the same set). In some embodiments, the PUCCH can be used to carry one of, a subset of, or all of the following information: failed serving cell index; failed CORESET-poolIndex or DL RS set index for BFD; a flag to indicate whether a new beam is detected; a new beam index selected from corresponding DL RS set for CBD. In some embodiments, the response for the PUCCH could be a PDCCH transmitted in a dedicated search space (SS) or CORESET. In some embodiments, the dedicated SS or CORESET could be configured by higher layer signaling, e.g. RRC signaling. 
     At item  220 , UE  202  receives a response to the reported BFRQ of item  218  from gNB  204 . In some embodiments, the response is an acknowledgement from gNB  204  (e.g., “ACK”) regarding the BFRQ. In some embodiments, for each of options  1 ,  2 , and  3 , after K number (e.g., K=28) of symbols after UE  202  receives the response at item  220  from gNB  204 , UE  202  can apply the new beam to all the CORESETs corresponding to the failed CORESET-poolIndex or UE  202  can apply the new beam to all the PUCCH resources corresponding to the failed CORESET-poolIndex if no BFRQ related signal is transmitted from the PUCCH resource. 
       FIG.  5    illustrates an example architecture of a system  500  of a network, in accordance with various embodiments. The following description is provided for an example system  500  that operates in conjunction with the LTE system standards and 5G or NR system standards as provided by 3GPP technical specifications. However, the example embodiments are not limited in this regard and the described embodiments may apply to other networks that benefit from the principles described herein, such as future 3GPP systems (e.g., Sixth Generation (6G)) systems, IEEE 802.16 protocols (e.g., WMAN, WiMAX, etc.), or the like. 
     As shown by  FIG.  5   , the system  500  includes UE  502  and UE  504 . In this example, the UE  502  and the UE  504  are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks), but may also comprise any mobile or non-mobile computing device, such as consumer electronics devices, cellular phones, smartphones, feature phones, tablet computers, wearable computer devices, personal digital assistants (PDAs), pagers, wireless handsets, desktop computers, laptop computers, in-vehicle infotainment (IVI), in-car entertainment (ICE) devices, an Instrument Cluster (IC), head-up display (HUD) devices, onboard diagnostic (OBD) devices, dashtop mobile equipment (DME), mobile data terminals (MDTs), Electronic Engine Management System (EEMS), electronic/engine control units (ECUs), electronic/engine control modules (ECMs), embedded systems, microcontrollers, control modules, engine management systems (EMS), networked or “smart” appliances, MTC devices, M2M, IoT devices, and/or the like. 
     In some embodiments, the UE  502  and/or the UE  504  may be IoT UEs, which may comprise a network access layer designed for low power IoT applications utilizing short-lived UE connections. An IoT UE can utilize technologies such as M2M or MTC for exchanging data with an MTC server or device via a PLMN, ProSe or D2D communication, sensor networks, or IoT networks. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An IoT network describes interconnecting IoT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. The IoT UEs may execute background applications (e.g., keep-alive messages, status updates, etc.) to facilitate the connections of the IoT network. 
     The UE  502  and UE  504  may be configured to connect, for example, communicatively couple, with an access node or radio access node (shown as (R)AN  516 ). In embodiments, the (R)AN  516  may be an NG RAN or a SG RAN, an E-UTRAN, or a legacy RAN, such as a UTRAN or GERAN. As used herein, the term “NG RAN” or the like may refer to a (R)AN  516  that operates in an NR or SG system, and the term “E-UTRAN” or the like may refer to a (R)AN  516  that operates in an LTE or 4G system. The UE  502  and UE  504  utilize connections (or channels) (shown as connection  506  and connection  508 , respectively), each of which comprises a physical communications interface or layer (discussed in further detail below). 
     In this example, the connection  506  and connection  508  are air interfaces to enable communicative coupling, and can be consistent with cellular communications protocols, such as a GSM protocol, a CDMA network protocol, a PTT protocol, a POC protocol, a UMTS protocol, a 3GPP LTE protocol, a SG protocol, a NR protocol, and/or any of the other communications protocols discussed herein. In embodiments, the UE  502  and UE  504  may directly exchange communication data via a ProSe interface  510 . The ProSe interface  510  may alternatively be referred to as a sidelink (SL) interface and may comprise one or more logical channels, including but not limited to a PSCCH, a PSSCH, a PSDCH, and a PSBCH. 
     The UE  504  is shown to be configured to access an AP  512  (also referred to as “WLAN node,” “WLAN,” “WLAN Termination,” “WT” or the like) via connection  514 . The connection  514  can comprise a local wireless connection, such as a connection consistent with any IEEE 802.11 protocol, wherein the AP  512  would comprise a wireless fidelity (Wi-Fi®) router. In this example, the AP  512  may be connected to the Internet without connecting to the core network of the wireless system (described in further detail below). In various embodiments, the UE  504 , (R)AN  516 , and AP  512  may be configured to utilize LWA operation and/or LWIP operation. The LWA operation may involve the UE  504  in RRC CONNECTED being configured by the RAN node  518  or the RAN node  520  to utilize radio resources of LTE and WLAN. LWIP operation may involve the UE  504  using WLAN radio resources (e.g., connection  514 ) via IPsec protocol tunneling to authenticate and encrypt packets (e.g., IP packets) sent over the connection  514 . IPsec tunneling may include encapsulating the entirety of original IP packets and adding a new packet header, thereby protecting the original header of the IP packets. 
     The (R)AN  516  can include one or more AN nodes, such as RAN node  518  and RAN node  520 , that enable the connection  506  and connection  508 . As used herein, the terms “access node,” “access point,” or the like may describe equipment that provides the radio baseband functions for data and/or voice connectivity between a network and one or more users. These access nodes can be referred to as BS, gNBs, RAN nodes, eNBs, NodeBs, RSUs TRxPs or TRPs, and so forth, and can comprise ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area (e.g., a cell). As used herein, the term “NG RAN node” or the like may refer to a RAN node that operates in an NR or SG system (for example, a gNB), and the term “E-UTRAN node” or the like may refer to a RAN node that operates in an LTE or 4G system  500  (e.g., an eNB). According to various embodiments, the RAN node  518  or RAN node  520  may be implemented as one or more of a dedicated physical device such as a macrocell base station, and/or a low power (LP) base station for providing femtocells, picocells or other like cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells. 
     In some embodiments, all or parts of the RAN node  518  or RAN node  520  may be implemented as one or more software entities running on server computers as part of a virtual network, which may be referred to as a CRAN and/or a virtual baseband unit pool (vBBUP). In these embodiments, the CRAN or vBBUP may implement a RAN function split, such as a PDCP split wherein RRC and PDCP layers are operated by the CRAN/vBBUP and other L2 protocol entities are operated by individual RAN nodes (e.g., RAN node  518  or RAN node  520 ); a MAC/PHY split wherein RRC, PDCP, RLC, and MAC layers are operated by the CRAN/vBBUP and the PHY layer is operated by individual RAN nodes (e.g., RAN node  518  or RAN node  520 ); or a “lower PHY” split wherein RRC, PDCP, RLC, MAC layers and upper portions of the PHY layer are operated by the CRAN/vBBUP and lower portions of the PHY layer are operated by individual RAN nodes. This virtualized framework allows the freed-up processor cores of the RAN node  518  or RAN node  520  to perform other virtualized applications. In some implementations, an individual RAN node may represent individual gNB-DUs that are connected to a gNB-CU via individual F1 interfaces (not shown by  FIG.  5   ). In these implementations, the gNB-DUs may include one or more remote radio heads or RFEMs, and the gNB-CU may be operated by a server that is located in the (R)AN  516  (not shown) or by a server pool in a similar manner as the CRAN/vBBUP. Additionally, or alternatively, one or more of the RAN node  518  or RAN node  520  may be next generation eNBs (ng-eNBs), which are RAN nodes that provide E-UTRA user plane and control plane protocol terminations toward the UE  502  and UE  504 , and are connected to an SGC via an NG interface (discussed infra). In V2X scenarios one or more of the RAN node  518  or RAN node  520  may be or act as RSUs. 
     The term “Road Side Unit” or “RSU” may refer to any transportation infrastructure entity used for V2X communications. An RSU may be implemented in or by a suitable RAN node or a stationary (or relatively stationary) UE, where an RSU implemented in or by a UE may be referred to as a “UE-type RSU,” an RSU implemented in or by an eNB may be referred to as an “eNB-type RSU,” an RSU implemented in or by a gNB may be referred to as a “gNB-type RSU,” and the like. In one example, an RSU is a computing device coupled with radio frequency circuitry located on a roadside that provides connectivity support to passing vehicle UEs (vUEs). The RSU may also include internal data storage circuitry to store intersection map geometry, traffic statistics, media, as well as applications/software to sense and control ongoing vehicular and pedestrian traffic. The RSU may operate on the 5.9 GHz Direct Short Range Communications (DSRC) band to provide very low latency communications required for high speed events, such as crash avoidance, traffic warnings, and the like. Additionally, or alternatively, the RSU may operate on the cellular V2X band to provide the aforementioned low latency communications, as well as other cellular communications services. Additionally, or alternatively, the RSU may operate as a Wi-Fi hotspot (2.4 GHz band) and/or provide connectivity to one or more cellular networks to provide uplink and downlink communication. The computing device(s) and some or all of the radio frequency circuitry of the RSU may be packaged in a weatherproof enclosure suitable for outdoor installation, and may include a network interface controller to provide a wired connection (e.g., Ethernet) to a traffic signal controller and/or a backhaul network. 
     The RAN node  518  and/or the RAN node  520  can terminate the air interface protocol and can be the first point of contact for the UE  502  and UE  504 . In some embodiments, the RAN node  518  and/or the RAN node  520  can fulfill various logical functions for the (R)AN  516  including, but not limited to, radio network controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management. 
     In embodiments, the UE  502  and UE  504  can be configured to communicate using OFDM communication signals with each other or with the RAN node  518  and/or the RAN node  520  over a multicarrier communication channel in accordance with various communication techniques, such as, but not limited to, an OFDMA communication technique (e.g., for downlink communications) or a SC-FDMA communication technique (e.g., for uplink and ProSe or sidelink communications), although the scope of the embodiments is not limited in this respect. The OFDM signals can comprise a plurality of orthogonal subcarriers. 
     In some embodiments, a downlink resource grid can be used for downlink transmissions from the RAN node  518  and/or the RAN node  520  to the UE  502  and UE  504 , while uplink transmissions can utilize similar techniques. The grid can be a time-frequency grid, called a resource grid or time-frequency resource grid, which is the physical resource in the downlink in each slot. Such a time-frequency plane representation is a common practice for OFDM systems, which makes it intuitive for radio resource allocation. Each column and each row of the resource grid corresponds to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to one slot in a radio frame. The smallest time-frequency unit in a resource grid is denoted as a resource element. Each resource grid comprises a number of resource blocks, which describe the mapping of certain physical channels to resource elements. Each resource block comprises a collection of resource elements; in the frequency domain, this may represent the smallest quantity of resources that currently can be allocated. There are several different physical downlink channels that are conveyed using such resource blocks. 
     According to various embodiments, the UE  502  and UE  504  and the RAN node  518  and/or the RAN node  520  communicate data (for example, transmit and receive) over a licensed medium (also referred to as the “licensed spectrum” and/or the “licensed band”) and an unlicensed shared medium (also referred to as the “unlicensed spectrum” and/or the “unlicensed band”). The licensed spectrum may include channels that operate in the frequency range of approximately 400 MHz to approximately 3.8 GHz, whereas the unlicensed spectrum may include the 5 GHz band. 
     To operate in the unlicensed spectrum, the UE  502  and UE  504  and the RAN node  518  or RAN node  520  may operate using LAA, eLAA, and/or feLAA mechanisms. In these implementations, the UE  502  and UE  504  and the RAN node  518  or RAN node  520  may perform one or more known medium-sensing operations and/or carrier-sensing operations in order to determine whether one or more channels in the unlicensed spectrum is unavailable or otherwise occupied prior to transmitting in the unlicensed spectrum. The medium/carrier sensing operations may be performed according to a listen-before-talk (LBT) protocol. 
     LBT is a mechanism whereby equipment (for example, UE  502  and UE  504 , RAN node  518  or RAN node  520 , etc.) senses a medium (for example, a channel or carrier frequency) and transmits when the medium is sensed to be idle (or when a specific channel in the medium is sensed to be unoccupied). The medium sensing operation may include CCA, which utilizes at least ED to determine the presence or absence of other signals on a channel in order to determine if a channel is occupied or clear. This LBT mechanism allows cellular/LAA networks to coexist with incumbent systems in the unlicensed spectrum and with other LAA networks. ED may include sensing RF energy across an intended transmission band for a period of time and comparing the sensed RF energy to a predefined or configured threshold. 
     Typically, the incumbent systems in the 5 GHz band are WLANs based on IEEE 802.11 technologies. WLAN employs a contention-based channel access mechanism, called CSMA/CA Here, when a WLAN node (e.g., a mobile station (MS) such as UE  502 , AP  512 , or the like) intends to transmit, the WLAN node may first perform CCA before transmission. Additionally, a backoff mechanism is used to avoid collisions in situations where more than one WLAN node senses the channel as idle and transmits at the same time. The backoff mechanism may be a counter that is drawn randomly within the CWS, which is increased exponentially upon the occurrence of collision and reset to a minimum value when the transmission succeeds. The LBT mechanism designed for LAA is somewhat similar to the CSMA/CA of WLAN. In some implementations, the LBT procedure for DL or UL transmission bursts including PDSCH or PUSCH transmissions, respectively, may have an LAA contention window that is variable in length between X and Y ECCA slots, where X and Y are minimum and maximum values for the CWSs for LAA. In one example, the minimum CWS for an LAA transmission may be 9 microseconds (μs); however, the size of the CWS and a MCOT (for example, a transmission burst) may be based on governmental regulatory requirements. 
     The LAA mechanisms are built upon CA technologies of LTE-Advanced systems. In CA, each aggregated carrier is referred to as a CC. A CC may have a bandwidth of 1.4, 3, 5, 10, 15 or 20 MHz and a maximum of five CCs can be aggregated, and therefore, a maximum aggregated bandwidth is 100 MHz. In FDD systems, the number of aggregated carriers can be different for DL and UL, where the number of UL CCs is equal to or lower than the number of DL component carriers. In some cases, individual CCs can have a different bandwidth than other CCs. In TDD systems, the number of CCs as well as the bandwidths of each CC is usually the same for DL and UL. 
     CA also comprises individual serving cells to provide individual CCs. The coverage of the serving cells may differ, for example, because CCs on different frequency bands will experience different pathloss. A primary service cell or PCell may provide a PCC for both UL and DL, and may handle RRC and NAS related activities. The other serving cells are referred to as SCells, and each SCell may provide an individual SCC for both UL and DL. The SCCs may be added and removed as required, while changing the PCC may require the UE  502  to undergo a handover. In LAA, eLAA, and feLAA, some or all of the SCells may operate in the unlicensed spectrum (referred to as “LAA SCells”), and the LAA SCells are assisted by a PCell operating in the licensed spectrum. When a UE is configured with more than one LAA SCell, the UE may receive UL grants on the configured LAA SCells indicating different PUSCH starting positions within a same subframe. 
     The PDSCH carries user data and higher-layer signaling to the UE  502  and UE  504 . The PDCCH carries information about the transport format and resource allocations related to the PDSCH channel, among other things. It may also inform the UE  502  and UE  504  about the transport format, resource allocation, and HARQ information related to the uplink shared channel. Typically, downlink scheduling (assigning control and shared channel resource blocks to the UE  504  within a cell) may be performed at any of the RAN node  518  or RAN node  520  based on channel quality information fed back from any of the UE  502  and UE  504 . The downlink resource assignment information may be sent on the PDCCH used for (e.g., assigned to) each of the UE  502  and UE  504 . 
     The PDCCH uses CCEs to convey the control information. Before being mapped to resource elements, the PDCCH complex-valued symbols may first be organized into quadruplets, which may then be permuted using a sub-block interleaver for rate matching. Each PDCCH may be transmitted using one or more of these CCEs, where each CCE may correspond to nine sets of four physical resource elements known as REGs. Four Quadrature Phase Shift Keying (QPSK) symbols may be mapped to each REG. The PDCCH can be transmitted using one or more CCEs, depending on the size of the DCI and the channel condition. There can be four or more different PDCCH formats defined in LTE with different numbers of CCEs (e.g., aggregation level, L=1, 2, 4, or 8). 
     Some embodiments may use concepts for resource allocation for control channel information that are an extension of the above-described concepts. For example, some embodiments may utilize an EPDCCH that uses PDSCH resources for control information transmission. The EPDCCH may be transmitted using one or more ECCEs. Similar to above, each ECCE may correspond to nine sets of four physical resource elements known as an EREGs. An ECCE may have other numbers of EREGs in some situations. 
     The RAN node  518  or RAN node  520  may be configured to communicate with one another via interface  522 . In embodiments where the system  500  is an LTE system (e.g., when CN  530  is an EPC), the interface  522  may be an X2 interface. The X2 interface may be defined between two or more RAN nodes (e.g., two or more eNBs and the like) that connect to an EPC, and/or between two eNBs connecting to the EPC. In some implementations, the X2 interface may include an X2 user plane interface (X2-U) and an X2 control plane interface (X2-C). The X2-U may provide flow control mechanisms for user data packets transferred over the X2 interface, and may be used to communicate information about the delivery of user data between eNBs. For example, the X2-U may provide specific sequence number information for user data transferred from a MeNB to an SeNB; information about successful in sequence delivery of PDCP PDUs to a UE  502  from an SeNB for user data; information of PDCP PDUs that were not delivered to a UE  502 ; information about a current minimum desired buffer size at the Se NB for transmitting to the UE user data; and the like. The X2-C may provide intra-LTE access mobility functionality, including context transfers from source to target eNBs, user plane transport control, etc.; load management functionality; as well as inter-cell interference coordination functionality. 
     In embodiments where the system  500  is a SG or NR system (e.g., when CN  530  is an SGC), the interface  522  may be an Xn interface. The Xn interface is defined between two or more RAN nodes (e.g., two or more gNBs and the like) that connect to SGC, between a RAN node  518  (e.g., a gNB) connecting to SGC and an eNB, and/or between two eNBs connecting to 5GC (e.g., CN  530 ). In some implementations, the Xn interface may include an Xn user plane (Xn-U) interface and an Xn control plane (Xn-C) interface. The Xn-U may provide non-guaranteed delivery of user plane PDUs and support/provide data forwarding and flow control functionality. The Xn-C may provide management and error handling functionality, functionality to manage the Xn-C interface; mobility support for UE  502  in a connected mode (e.g., CM-CONNECTED) including functionality to manage the UE mobility for connected mode between one or more RAN node  518  or RAN node  520 . The mobility support may include context transfer from an old (source) serving RAN node  518  to new (target) serving RAN node  520 ; and control of user plane tunnels between old (source) serving RAN node  518  to new (target) serving RAN node  520 . A protocol stack of the Xn-U may include a transport network layer built on Internet Protocol (IP) transport layer, and a GTP-U layer on top of a UDP and/or IP layer(s) to carry user plane PDUs. The Xn-C protocol stack may include an application layer signaling protocol (referred to as Xn Application Protocol (Xn-AP)) and a transport network layer that is built on SCTP. The SCTP may be on top of an IP layer, and may provide the guaranteed delivery of application layer messages. In the transport IP layer, point-to-point transmission is used to deliver the signaling PDUs. In other implementations, the Xn-U protocol stack and/or the Xn-C protocol stack may be same or similar to the user plane and/or control plane protocol stack(s) shown and described herein. 
     The (R)AN  516  is shown to be communicatively coupled to a core network-in this embodiment, CN  530 . The CN  530  may comprise one or more network elements  532 , which are configured to offer various data and telecommunications services to customers/subscribers (e.g., users of UE  502  and UE  504 ) who are connected to the CN  530  via the (R)AN  516 . The components of the CN  530  may be implemented in one physical node or separate physical nodes including components to read and execute instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium). In some embodiments, NFV may be utilized to virtualize any or all of the above-described network node functions via executable instructions stored in one or more computer-readable storage mediums (described in further detail below). A logical instantiation of the CN  530  may be referred to as a network slice, and a logical instantiation of a portion of the CN  530  may be referred to as a network sub-slice. NFV architectures and infrastructures may be used to virtualize one or more network functions, alternatively performed by proprietary hardware, onto physical resources comprising a combination of industry-standard server hardware, storage hardware, or switches. In other words, NFV systems can be used to execute virtual or reconfigurable implementations of one or more EPC components/functions. 
     Generally, an application server  534  may be an element offering applications that use IP bearer resources with the core network (e.g., UMTS PS domain, LTE PS data services, etc.). The application server  534  can also be configured to support one or more communication services (e.g., VoIP sessions, PTT sessions, group communication sessions, social networking services, etc.) for the UE  502  and UE  504  via the EPC. The application server  534  may communicate with the CN  530  through an IP communications interface  536 . 
     In embodiments, the CN  530  may be an SGC, and the (R)AN  116  may be connected with the CN  530  via an NG interface  524 . In embodiments, the NG interface  524  may be split into two parts, an NG user plane (NG-U) interface  526 , which carries traffic data between the RAN node  518  or RAN node  520  and a UPF, and the S1 control plane (NG-C) interface  528 , which is a signaling interface between the RAN node  518  or RAN node  520  and AMFs. 
     In embodiments, the CN  530  may be a SG CN, while in other embodiments, the CN  530  may be an EPC). Where CN  530  is an EPC, the (R)AN  116  may be connected with the CN  530  via an S1 interface  524 . In embodiments, the S1 interface  524  may be split into two parts, an S1 user plane (S1-U) interface  526 , which carries traffic data between the RAN node  518  or RAN node  520  and the S-GW, and the S1-MME interface  528 , which is a signaling interface between the RAN node  518  or RAN node  520  and MMEs. 
       FIG.  6    illustrates example components of a device  600  in accordance with some embodiments. In some embodiments, the device  600  may include application circuitry  602 , baseband circuitry  604 , Radio Frequency (RF) circuitry (shown as RF circuitry  620 ), front-end module (FEM) circuitry (shown as FEM circuitry  630 ), one or more antennas  632 , and power management circuitry (PMC) (shown as PMC  634 ) coupled together at least as shown. The components of the illustrated device  600  may be included in a UE or a RAN node. In some embodiments, the device  600  may include fewer elements (e.g., a RAN node may not utilize application circuitry  602 , and instead include a processor/controller to process IP data received from an EPC). In some embodiments, the device  600  may include additional elements such as, for example, memory/storage, display, camera, sensor, or input/output (I/O) interface. In other embodiments, the components described below may be included in more than one device (e.g., said circuitries may be separately included in more than one device for Cloud-RAN (C-RAN) implementations). 
     The application circuitry  602  may include one or more application processors. For example, the application circuitry  602  may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors, application processors, etc.). The processors may be coupled with or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications or operating systems to run on the device  600 . In some embodiments, processors of application circuitry  602  may process IP data packets received from an EPC. 
     The baseband circuitry  604  may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry  604  may include one or more baseband processors or control logic to process baseband signals received from a receive signal path of the RF circuitry  620  and to generate baseband signals for a transmit signal path of the RF circuitry  620 . The baseband circuitry  604  may interface with the application circuitry  602  for generation and processing of the baseband signals and for controlling operations of the RF circuitry  620 . For example, in some embodiments, the baseband circuitry  604  may include a third generation (3G) baseband processor (3G baseband processor  606 ), a fourth generation (4G) baseband processor (4G baseband processor  608 ), a fifth generation (5G) baseband processor (5G baseband processor  610 ), or other baseband processor(s)  612  for other existing generations, generations in development or to be developed in the future (e.g., second generation (2G), sixth generation (6G), etc.). The baseband circuitry  604  (e.g., one or more of baseband processors) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry  620 . In other embodiments, some or all of the functionality of the illustrated baseband processors may be included in modules stored in the memory  618  and executed via a Central Processing Unit (CPU  614 ). The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry  604  may include Fast-Fourier Transform (FFT), precoding, or constellation mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry  604  may include convolution, tail-biting convolution, turbo, Viterbi, or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments. 
     In some embodiments, the baseband circuitry  604  may include a digital signal processor (DSP), such as one or more audio DSP(s)  616 . The one or more audio DSP(s)  616  may include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments. Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry  604  and the application circuitry  602  may be implemented together such as, for example, on a system on a chip (SOC). 
     In some embodiments, the baseband circuitry  604  may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry  604  may support communication with an evolved universal terrestrial radio access network (EUTRAN) or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), or a wireless personal area network (WPAN). Embodiments in which the baseband circuitry  604  is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry. 
     The RF circuitry  620  may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry  620  may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. The RF circuitry  620  may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry  630  and provide baseband signals to the baseband circuitry  604 . The RF circuitry  620  may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry  604  and provide RF output signals to the FEM circuitry  630  for transmission. 
     In some embodiments, the receive signal path of the RF circuitry  620  may include mixer circuitry  622 , amplifier circuitry  624  and filter circuitry  626 . In some embodiments, the transmit signal path of the RF circuitry  620  may include filter circuitry  626  and mixer circuitry  622 . The RF circuitry  620  may also include synthesizer circuitry  628  for synthesizing a frequency for use by the mixer circuitry  622  of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry  622  of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry  630  based on the synthesized frequency provided by synthesizer circuitry  628 . The amplifier circuitry  624  may be configured to amplify the down-converted signals and the filter circuitry  626  may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry  604  for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, the mixer circuitry  622  of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect. 
     In some embodiments, the mixer circuitry  622  of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry  628  to generate RF output signals for the FEM circuitry  630 . The baseband signals may be provided by the baseband circuitry  604  and may be filtered by the filter circuitry  626 . 
     In some embodiments, the mixer circuitry  622  of the receive signal path and the mixer circuitry  622  of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and upconversion, respectively. In some embodiments, the mixer circuitry  622  of the receive signal path and the mixer circuitry  622  of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry  622  of the receive signal path and the mixer circuitry  622  may be arranged for direct downconversion and direct upconversion, respectively. In some embodiments, the mixer circuitry  622  of the receive signal path and the mixer circuitry  622  of the transmit signal path may be configured for super-heterodyne operation. 
     In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these alternate embodiments, the RF circuitry  620  may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry and the baseband circuitry  604  may include a digital baseband interface to communicate with the RF circuitry  620 . 
     In some dual-mode embodiments, a separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect. 
     In some embodiments, the synthesizer circuitry  628  may be a fractional-N synthesizer or a fractional N/N+1 synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry  628  may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider. 
     The synthesizer circuitry  628  may be configured to synthesize an output frequency for use by the mixer circuitry  622  of the RF circuitry  620  based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry  628  may be a fractional N/N+1 synthesizer. 
     In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry  604  or the application circuitry  602  (such as an applications processor) depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a look-up table based on a channel indicated by the application circuitry  602 . 
     Synthesizer circuitry  628  of the RF circuitry  620  may include a divider, a delay-locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+1 (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip-flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle. 
     In some embodiments, the synthesizer circuitry  628  may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fLO). In some embodiments, the RF circuitry  620  may include an IQ/polar converter. 
     The FEM circuitry  630  may include a receive signal path which may include circuitry configured to operate on RF signals received from one or more antennas  632 , amplify the received signals and provide the amplified versions of the received signals to the RF circuitry  620  for further processing. The FEM circuitry  630  may also include a transmit signal path which may include circuitry configured to amplify signals for transmission provided by the RF circuitry  620  for transmission by one or more of the one or more antennas  632 . In various embodiments, the amplification through the transmit or receive signal paths may be done solely in the RF circuitry  620 , solely in the FEM circuitry  630 , or in both the RF circuitry  620  and the FEM circuitry  630 . 
     In some embodiments, the FEM circuitry  630  may include a TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry  630  may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry  630  may include an LNA to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry  620 ). The transmit signal path of the FEM circuitry  630  may include a power amplifier (PA) to amplify input RF signals (e.g., provided by the RF circuitry  620 ), and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas  632 ). 
     In some embodiments, the PMC  634  may manage power provided to the baseband circuitry  604 . In particular, the PMC  634  may control power-source selection, voltage scaling, battery charging, or DC-to-DC conversion. The PMC  634  may often be included when the device  600  is capable of being powered by a battery, for example, when the device  600  is included in a UE. The PMC  634  may increase the power conversion efficiency while providing desirable implementation size and heat dissipation characteristics. 
       FIG.  6    shows the PMC  634  coupled only with the baseband circuitry  604 . However, in other embodiments, the PMC  634  may be additionally or alternatively coupled with, and perform similar power management operations for, other components such as, but not limited to, the application circuitry  602 , the RF circuitry  620 , or the FEM circuitry  630 . 
     In some embodiments, the PMC  634  may control, or otherwise be part of, various power saving mechanisms of the device  600 . For example, if the device  600  is in an RRC Connected state, where it is still connected to the RAN node as it expects to receive traffic shortly, then it may enter a state known as Discontinuous Reception Mode (DRX) after a period of inactivity. During this state, the device  600  may power down for brief intervals of time and thus save power. 
     If there is no data traffic activity for an extended period of time, then the device  600  may transition off to an RRC Idle state, where it disconnects from the network and does not perform operations such as channel quality feedback, handover, etc. The device  600  goes into a very low power state and it performs paging where again it periodically wakes up to listen to the network and then powers down again. The device  600  may not receive data in this state, and in order to receive data, it transitions back to an RRC Connected state. 
     An additional power saving mode may allow a device to be unavailable to the network for periods longer than a paging interval (ranging from seconds to a few hours). During this time, the device is totally unreachable to the network and may power down completely. Any data sent during this time incurs a large delay and it is assumed the delay is acceptable. 
     Processors of the application circuitry  602  and processors of the baseband circuitry  604  may be used to execute elements of one or more instances of a protocol stack. For example, processors of the baseband circuitry  604 , alone or in combination, may be used to execute Layer 3, Layer 2, or Layer 1 functionality, while processors of the application circuitry  602  may utilize data (e.g., packet data) received from these layers and further execute Layer 4 functionality (e.g., transmission communication protocol (TCP) and user datagram protocol (UDP) layers). As referred to herein, Layer 3 may comprise a radio resource control (RRC) layer, described in further detail below. As referred to herein, Layer 2 may comprise a medium access control (MAC) layer, a radio link control (RLC) layer, and a packet data convergence protocol (PDCP) layer, described in further detail below. As referred to herein, Layer 1 may comprise a physical (PHY) layer of a UE/RAN node, described in further detail below. 
       FIG.  7    illustrates example interfaces  700  of baseband circuitry in accordance with some embodiments. As discussed above, the baseband circuitry  604  of  FIG.  6    may comprise 3G baseband processor  606 , 4G baseband processor  608 , 5G baseband processor  610 , other baseband processor(s)  612 , CPU  614 , and a memory  618  utilized by said processors. As illustrated, each of the processors may include a respective memory interface  702  to send/receive data to/from the memory  618 . 
     The baseband circuitry  604  may further include one or more interfaces to communicatively couple to other circuitries/devices, such as a memory interface  704  (e.g., an interface to send/receive data to/from memory external to the baseband circuitry  604 ), an application circuitry interface  706  (e.g., an interface to send/receive data to/from the application circuitry  602  of  FIG.  6   ), an RF circuitry interface  708  (e.g., an interface to send/receive data to/from RF circuitry  620  of  FIG.  6   ), a wireless hardware connectivity interface  710  (e.g., an interface to send/receive data to/from Near Field Communication (NFC) components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and other communication components), and a power management interface  712  (e.g., an interface to send/receive power or control signals to/from the PMC  634 . 
       FIG.  8    is a block diagram illustrating components  800 , according to some example embodiments, able to read instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) and perform any one or more of the methodologies discussed herein. Specifically,  FIG.  8    shows a diagrammatic representation of hardware resources  802  including one or more processors  812  (or processor cores), one or more memory/storage devices  818 , and one or more communication resources  820 , each of which may be communicatively coupled via a bus  822 . For embodiments where node virtualization (e.g., NFV) is utilized, a hypervisor  804  may be executed to provide an execution environment for one or more network slices/sub-slices to utilize the hardware resources  802 . 
     The processors  812  (e.g., a central processing unit (CPU), a reduced instruction set computing (RISC) processor, a complex instruction set computing (CISC) processor, a graphics processing unit (GPU), a digital signal processor (DSP) such as a baseband processor, an application specific integrated circuit (ASIC), a radio-frequency integrated circuit (RFIC), another processor, or any suitable combination thereof) may include, for example, a processor  814  and a processor  816 . 
     The memory/storage devices  818  may include main memory, disk storage, or any suitable combination thereof. The memory/storage devices  818  may include, but are not limited to any type of volatile or non-volatile memory such as dynamic random access memory (DRAM), static random-access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), Flash memory, solid-state storage, etc. 
     The communication resources  820  may include interconnection or network interface components or other suitable devices to communicate with one or more peripheral devices  806  or one or more databases  808  via a network  810 . For example, the communication resources  820  may include wired communication components (e.g., for coupling via a Universal Serial Bus (USB)), cellular communication components, NFC components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and other communication components. 
     Instructions  824  may comprise software, a program, an application, an applet, an app, or other executable code for causing at least any of the processors  812  to perform any one or more of the methodologies discussed herein. The instructions  824  may reside, completely or partially, within at least one of the processors  812  (e.g., within the processor&#39;s cache memory), the memory/storage devices  818 , or any suitable combination thereof. Furthermore, any portion of the instructions  824  may be transferred to the hardware resources  802  from any combination of the peripheral devices  806  or the databases  808 . Accordingly, the memory of the processors  812 , the memory/storage devices  818 , the peripheral devices  806 , and the databases  808  are examples of computer-readable and machine-readable media. 
     For one or more embodiments, at least one of the components set forth in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, and/or methods as set forth in the Example Section below. For example, the baseband circuitry as described above in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth below. For another example, circuitry associated with a UE, base station, network element, etc. as described above in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth below in the example section. 
     Example Section 
     The following examples pertain to further embodiments. 
     Example 1 includes a non-transitory computer-readable storage medium for a user equipment (UE) to perform beam failure recovery (BFR) in a multiple Downlink Control Information (mDCI) mode. The computer-readable storage medium includes instructions that when executed by a computer, cause the computer to receive, by the UE, a Downlink Reference Signal (DL RS) set from a next generation Node B (gNB), the DL RS set associated with a link between the UE and the gNB and indicating beam failure detection (BFD) is to be performed for the link, the DL RS set received periodically by the UE from the gNB. The instructions further cause the computer to perform, by the UE, a beam failure detection (BFD) for the link using the DL RS set, the BFD determining a beam failure for the link by determining that a block error ratio (BLER) for the link is larger than a BLER threshold. The instructions further control the computer to perform, by the UE, a candidate beam detection (CBD) for the link, the CBD determining a candidate beam for the link by determining a beam having a reference signal receiving power (RSRP) that is larger than an RSRP threshold. The instructions further control the computer to transmit, by the UE, a beam failure recovery request (BFRQ) indicating the link to the gNB. 
     Example 2 includes the non-transitory computer readable storage medium of example 1, wherein the DL RS set corresponds to one or more CORESETs having a same CORESET-poolIndex value. 
     Example 3 includes the non-transitory computer readable storage medium of example 1, wherein the DL RS set includes a DL RS that is a Channel State Information Reference Signal (CSI-RS) or a synchronization signal block (SSB) indicating BFD is to be performed for the link. 
     Example 4 includes the non-transitory computer readable storage medium of example 3, wherein the DL RS is configured by radio resource control (RRC) signaling. 
     Example 5 includes the non-transitory computer readable storage medium of example 1, wherein the computer-readable storage medium includes instructions that cause the computer to receive, by the UE, an additional DL RS set from the gNB, the additional DL RS set associated with the link and configuring the UE for the CBD, the additional DL RS set received periodically by the UE from the gNB. 
     Example 6 includes the non-transitory computer readable storage medium of example 5, wherein the additional DL RS set corresponds to one or more CORESETs having the same CORESET-poolIndex. 
     Example 7 includes the non-transitory computer readable storage medium of example 5, wherein the additional DL RS set includes a DL RS that is a CSI-RS or a SSB indicating CBD is to be performed for the link. 
     Example 8 includes the non-transitory computer readable storage medium of example 7, wherein the computer-readable storage medium includes instructions that cause the computer to determine, by the UE, that the DL RS of the additional DL RS set is not configured by a gNB and use, by the UE, a default DL RS, wherein the default DL RS is an SSB from an initial bandwidth part or a current bandwidth part and indicates CBD for the link. 
     Example 9 includes the non-transitory computer readable storage medium of example 1, wherein the BFRQ is transmitted via a Media Access Control Control Element (MAC CE) that includes a failed CORESET-poolIndex or DL RS set index corresponding to the link. 
     Example 10 includes the non-transitory computer readable storage medium of example 1, wherein the BFRQ is transmitted using a physical random access channel (PRACH), wherein the UE is configured with a PRACH resource associated with a DL RS for the CBD of the link, the PRACH resource belonging to a group of resources for the same CORESET-poolIndex. 
     Example 11 includes the non-transitory computer readable storage medium of example 1, wherein the BFRQ is transmitted using multi-bit PUCCH resources, wherein each PUCCH resource of the PUCCH resources is associated with the same CORESET-poolIndex, and wherein each PUCCH resource includes a failed CORESET-poolIndex or DL RS set index corresponding to the link. 
     Example 12 includes the non-transitory computer readable storage medium of example 1, wherein the computer-readable storage medium includes instructions that cause the computer to receive, by the UE, a response regarding the BFRQ from the gNB and apply, by the UE, the candidate beam to one or more CORESETs corresponding to a failed CORESET-poolIndex or DL RS set index corresponding to the link. 
     Example 13 includes the non-transitory computer readable storage medium of example 1, wherein the BFD and the CBD are performed sequentially. 
     Example 14 includes the non-transitory computer readable storage medium of example 1, wherein the BFD and the CBD are performed simultaneously. 
     Example 15 includes the non-transitory computer readable storage medium of example 1, wherein the computer-readable storage medium includes instructions that cause the computer to receive, at the UE, control signaling from the gNB that enables multi-DCI BFR. 
     Example 16 includes the non-transitory computer readable storage medium of example 15, wherein the control signaling is RRC signaling. 
     Example 17 includes the non-transitory computer readable storage medium of example 15, wherein the control signaling includes a plurality of DL RS sets configured for BFR and wherein the computer-readable storage medium includes instructions that cause the computer to determine multi-DCI BFR is enabled due to the presence of the plurality of DL RS sets configured for BFR. 
     Example 18 includes a method for beam failure recovery (BFR) in a multiple Downlink Control Information (mDCI) mode. The method comprises receiving, by a UE, a Downlink Reference Signal (DL RS) set from a next generation Node B (gNB), the DL RS set associated with a link between the UE and the gNB and indicating beam failure detection (BFD) is to be performed for the link, the DL RS set received periodically by the UE from the gNB. The method further comprises performing, by the UE, a beam failure detection (BFD) for the link using the DL RS set, the BFD determining a beam failure for the link by determining that a block error ratio (BLER) for the link is larger than a BLER threshold. The method further comprises performing, by the UE, a candidate beam detection (CBD) for the link, the CBD determining a candidate beam for the link by determining a beam having a reference signal receiving power (RSRP) that is larger than an RSRP threshold. The method further comprises transmitting, by the UE, a beam failure recovery request (BFRQ) indicating the link to the gNB. 
     Example 19 includes an apparatus for a user equipment (UE) to perform beam failure recovery (BFR) in a multiple Downlink Control Information (mDCI) mode. The apparatus comprises a processor and a memory storing instructions that, when executed by the processor, configure the apparatus to receive, by the UE, a Downlink Reference Signal (DL RS) set from a next generation Node B (gNB), the DL RS set associated with a link between the UE and the gNB and indicating beam failure detection (BFD) is to be performed for the link, the DL RS set received periodically by the UE from the gNB. The instructions further configure the apparatus to perform, by the UE, a beam failure detection (BFD) for the link using the DL RS set, the BFD determining a beam failure for the link by determining that a block error ratio (BLER) for the link is larger than a BLER threshold. The instructions further configure the apparatus to perform, by the UE, a candidate beam detection (CBD) for the link, the CBD determining a candidate beam for the link by determining a beam having a reference signal receiving power (RSRP) that is larger than an RSRP threshold. The instructions further configure the apparatus to transmit, by the UE, a beam failure recovery request (BFRQ) indicating the link to the gNB 
     Example 20 includes the apparatus of example 19, wherein the DL RS set corresponds to one or more CORESETs having a same CORESET-poolIndex value. 
     Example 21 may include an apparatus comprising means to perform one or more elements of a method described in or related to any of the above Examples, or any other method or process described herein. 
     Example 22 may include one or more non-transitory computer-readable media comprising instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one or more elements of a method described in or related to any of the above Examples, or any other method or process described herein. 
     Example 23 may include an apparatus comprising logic, modules, or circuitry to perform one or more elements of a method described in or related to any of the above Examples, or any other method or process described herein. 
     Example 24 may include a method, technique, or process as described in or related to any of the above Examples, or portions or parts thereof. 
     Example 25 may include an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform the method, techniques, or process as described in or related to any of the above Examples, or portions thereof. 
     Example 26 may include a signal as described in or related to any of the above 
     Examples, or portions or parts thereof. 
     Example 27 may include a datagram, packet, frame, segment, protocol data unit (PDU), or message as described in or related to any of the above Examples, or portions or parts thereof, or otherwise described in the present disclosure. 
     Example 28 may include a signal encoded with data as described in or related to any of the above Examples, or portions or parts thereof, or otherwise described in the present disclosure. 
     Example 29 may include a signal encoded with a datagram, packet, frame, segment, PDU, or message as described in or related to any of the above Examples, or portions or parts thereof, or otherwise described in the present disclosure. 
     Example 30 may include an electromagnetic signal carrying computer-readable instructions, wherein execution of the computer-readable instructions by one or more processors is to cause the one or more processors to perform the method, techniques, or process as described in or related to any of the above Examples, or portions thereof. 
     Example 31 may include a computer program comprising instructions, wherein execution of the program by a processing element is to cause the processing element to carry out the method, techniques, or process as described in or related to any of the above Examples, or portions thereof. 
     Example 32 may include a signal in a wireless network as shown and described herein. 
     Example 33 may include a method of communicating in a wireless network as shown and described herein. 
     Example 34 may include a system for providing wireless communication as shown and described herein. 
     Example 35 may include a device for providing wireless communication as shown and described herein. 
     Any of the above described examples may be combined with any other example (or combination of examples), unless explicitly stated otherwise. The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of embodiments to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments. 
     Embodiments and implementations of the systems and methods described herein may include various operations, which may be embodied in machine-executable instructions to be executed by a computer system. A computer system may include one or more general-purpose or special-purpose computers (or other electronic devices). The computer system may include hardware components that include specific logic for performing the operations or may include a combination of hardware, software, and/or firmware. 
     It should be recognized that the systems described herein include descriptions of specific embodiments. These embodiments can be combined into single systems, partially combined into other systems, split into multiple systems or divided or combined in other ways. In addition, it is contemplated that parameters, attributes, aspects, etc. of one embodiment can be used in another embodiment. The parameters, attributes, aspects, etc. are merely described in one or more embodiments for clarity, and it is recognized that the parameters, attributes, aspects, etc. can be combined with or substituted for parameters, attributes, aspects, etc. of another embodiment unless specifically disclaimed herein. 
     It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. 
     Although the foregoing has been described in some detail for purposes of clarity, it will be apparent that certain changes and modifications may be made without departing from the principles thereof. It should be noted that there are many alternative ways of implementing both the processes and apparatuses described herein. Accordingly, the present embodiments are to be considered illustrative and not restrictive, and the description is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.

Metadata:
Filing Date: 20200515
Publication Date: 20240730
Grant Date: 20240730
Priority Date: 20200515
Inventors: ZHANG, YUSHU
YAO, CHUNHAI
ZHANG, DAWEI
SUN, HAITONG
HE, HONG
ZENG, WEI
YANG, WEIDONG
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W72/23", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W74/0841", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L1/203", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W76/19", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L5/0053", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04L5/0048", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B7/088", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B7/088", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04B7/0695", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W76/19", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W74/0841", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/23", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L1/203", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B7/088", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 78526286