REPORTING RADIO-RELATED FAILURES WITH RLM/BLD RELAXATION INFORMATION

TECHNICAL FIELD

The present disclosure relates generally to wireless networks, and more specifically to techniques for improving the capability of a radio access network (RAN) to diagnose causes of radio-related failures reported by user equipment (UEs).

BACKGROUND

Currently the fifth generation (5G) of cellular systems is being standardized within the Third-Generation Partnership Project (3GPP). 5G is developed for maximum flexibility to support multiple and substantially different use cases. These include enhanced mobile broadband (eMBB), machine type communications (MTC), ultra-reliable low latency communications (URLLC), side-link device-to-device (D2D), and several other use cases.

Figure 1 illustrates a high-level view of an exemplary 5G network architecture, consisting of a Next Generation Radio Access Network (NG-RAN, 199) and a 5G Core (5GC, 198). The NG-RAN can include one or more gNodeB’s (gNBs) connected to the 5GC via one or more NG interfaces, such as gNBs (100, 150) connected via respective interfaces (102, 152). More specifically, the gNBs can be connected to one or more Access and Mobility Management Functions (AMFs) in the 5GC via respective NG-C interfaces and to one or more User Plane Functions (UPFs) in 5GC via respective NG-U interfaces. Various other network functions (NFs) can be included in the 5GC, as described in more detail below.

In addition, the gNBs can be connected to each other via one or more Xn interfaces, such as Xn interface (140) between gNBs (100, 150). The radio technology for the NG-RAN is often referred to as “New Radio” (NR). With respect to the NR interface to UEs, each of the gNBs can support frequency division duplexing (FDD), time division duplexing (TDD), or a combination thereof. Each of the gNBs can serve a geographic coverage area including one or more cells and, in some cases, can also use various directional beams to provide coverage in the respective cells. In general, a DL “beam” is a coverage area of a network-transmitted reference signal (RS) that may be measured or monitored by a UE.

The NG-RAN is layered into a Radio Network Layer (RNL) and a Transport Network Layer (TNL). The NG-RAN architecture, /.< ., the NG-RAN logical nodes and interfaces between them, is defined as part of the RNL. For each NG-RAN interface (NG, Xn, Fl) the related TNL protocol and the functionality are specified. The TNL provides services for user plane transport and signaling transport. The NG RAN logical nodes shown in Figure 1 include a Central Unit (CU or gNB-CU, e.g., 110) and one or more Distributed Units (DU or gNB-DU, e.g., 120, 130). CUs are logical nodes that host higher-layer protocols and perform various gNB functions such controlling the operation of DUs. DUs are decentralized logical nodes that host lower layer protocols and can include, depending on the functional split option, various subsets of the gNB functions.

A gNB-CU connects to one or more gNB-DUs over respective Fl logical interfaces (e.g., 122 and 132 shown in Figure 1). However, a gNB-DU can be connected to only a single gNB- CU. The gNB-CU and its connected gNB-DU(s) are only visible to other gNBs and the 5GC as a gNB. In other words, the Fl interface is not visible beyond gNB-CU.

Self-Organizing Networks (SON) is an automation technology used to improve the planning, configuration, management, optimization, and healing of mobile RANs. SON functionality can broadly be categorized as either self-optimization or self-configuration. Selfoptimization employs UE and network measurements to auto-tune the RAN. This occurs when RAN nodes are in an operational state, after the node’s RF transmitter interface is switched on. Self-configuration operations include optimization and adaptation, which are generally performed before the RAN nodes are in operational state.

Self-configuration and self-optimization features for NR networks are described in 3GPP TS 38.300 (vl6.5.0) and for fourth generation Long-Term Evolution (LTE) networks in 3GPP TS 36.300 (vl6.5.0). These features include dynamic configuration, automatic neighbor relations (ANR), mobility load balancing (MLB), mobility robustness optimization (MRO), random access channel (RACH) optimization, capacity and coverage optimization (CCO), and mobility settings change.

Seamless mobility is a key feature of 3GPP radio access technologies (RATs). In general, a RAN (e.g., NG-RAN) configures a UE to perform and report radio resource management (RRM) measurements to assist network-controlled mobility decisions, such as for handover from a serving cell to a neighbor cell. Seamless handovers ensure that the UE moves around in the coverage area of different cells without excessive interruption to data transmission. However, there will be scenarios when the network fails to handover the UE to the “correct” neighbor cell in time, which can cause the UE to declare radio link failure (RLF) or handover failure (HOF). This can occur before the UE sends a measurement report in a source cell, before the UE receives a handover command to a target cell, shortly after the UE executes a successful handover to the target cell, or upon a HOF to the target cell (e.g., upon expiry of timer T304, started when the UE starts synchronization with the target cell).

An RLF reporting procedure was introduced as part of the mobility robustness optimization (MRO) in LTE Rel-9. In this procedure, a UE logs relevant information at the time of RLF and later reports such information to the network via a target cell to which the UE ultimately connects (e.g., after reestablishment). The reported information can include RRM measurements of various neighbor cells prior to the mobility operation (e.g., handover).

When connected to the NG-RAN (e.g., in RRC_CONNECTED state), UEs are required to conduct radio link monitoring (RLM) and beam failure detection (BFD) measurements to monitor radio link quality. For RLM/BFD in NR, UEs can be configured to measure synchronization signal/PBCH blocks (SSB) and/or channel state information (CSI) reference signals (CSI-RS). For BFD, a UE declares beam failure when a quantity of beam failure indications from LI (PHY) reaches a configured threshold before a configured timer expires. The UE then initiates a random access (RA) procedure on the primary cell (PCell) of the cell group in which the beam failure was detected and selects a suitable beam to perform beam failure recovery (BFR). If the serving RAN node provides dedicated RA resources for certain beams, the UE will prioritize those.

3GPP TS 38.331 (vl7.1.0) specifies that a UE can be configured to relax its RLM/BFD procedures for the sake of reducing UE energy consumption (also referred to as “energy saving”), with the measurement relaxation parameters specified in 3GPP TS 38.133 (vl7.6.0). In particular, the UE can perform relaxed RLM/BFD measurements only when the UE meets certain relaxation criteria (e.g., low mobility state and/or good serving cell quality) configured by the network. For example, the RLM/BFD relaxation parameters used by the network can be configured using SON functionality, e.g., with self-optimization and/or self-configuration.

SUMMARY

However, improper configuration of RLM/BDF relaxation parameters by SON functionality can negatively impact UE performance. For example, a UE may experience bad radio coverage but does not declare RLF early enough due to relaxed RLM/BFD measurements. Because the UE operates in bad coverage conditions for a longer duration, the UEs quality of service (QoS) will be degraded, as will the end user’s quality of experience (QoE) for applications/ services running on the UE.

Similarly, the UE may not perform BFR early enough due to relaxed RLM/BFD measurements, which can lead to declaring RLF. Put differently, a timely BFR could prevent the UE from experiencing a subsequent RLF, but the relaxed RLM/BFD measurements removes this possibility.

An object of embodiments of the present disclosure is to improve configuration and use of relaxed RLM/BFD measurements for UEs in a RAN, such as by providing, enabling, and/or facilitating solutions to overcome exemplary problems summarized above and described in more detail below. Embodiments include methods e.g., procedures) for UE configured for operation in a radio access network (RAN, e.g., E-UTRAN, NG-RAN).

These exemplary methods can include performing RLM and/or BFD in a serving cell provided by a first RAN node. These exemplary methods can also include detecting a radiorelated failure in the serving cell based on performing RLM and/or BFD. These exemplary methods can also include sending, to the first RAN node or to a second RAN node, a failure report including RLM/BFD relaxation information pertaining to the RLM and/or the BFD being performed when the radio-related failure was detected.

In some embodiments, these exemplary methods can also include, before performing RLM and BFD in the serving cell, receiving from the first RAN node an RLM/BFD relaxation configuration that includes one or more of the following: one or more first conditions that must be met to perform RLM according to a relaxed RLM measurement configuration, and one or more second conditions that must be met to perform BFD according to a relaxed BFD measurement configuration.

In some of these embodiments, performing RLM in the serving cell can include the following operations:

• determining whether the one or more first conditions are met;

• performing RLM in the serving cell according to the relaxed RLM measurement configuration when it is determined that the one or more first conditions are met;

• performing RLM in the serving cell according to a normal or non-relaxed RLM measurement configuration when it is determined that the one or more first conditions are not met;

In some of these embodiments, performing BFD in the serving cell can include the following operations:

• determining whether the one or more second conditions are met;

• performing BFD in the serving cell according to the relaxed BFD measurement configuration when it is determined that the one or more second conditions are met; and

• performing BFD in the serving cell according to a normal or non-relaxed BFD measurement configuration when it is determined that the one or more second conditions are not met.

In some of these embodiments, the RLM/BFD relaxation information in the failure report includes one or more the following:

• a first indication of whether the UE was performing the RLM in the serving cell according to the relaxed RLM measurement configuration, when the radio-related failure was detected; • at least a portion of the first conditions;

• a duration that the UE had been performing RLM in the serving cell according to the relaxed RLM measurement configuration, when the radio-related failure was detected;

• a second indication of whether the UE was performing the BFD in the serving cell according to the relaxed BFD measurement configuration, when the radio-related failure was detected;

• at least a portion of the second conditions; and

• a duration that the UE had been performing the BFD in the serving cell according to the relaxed BFD measurement configuration, when the radio-related failure was detected.

In some of these embodiments, the one or more first conditions include one or more first good serving cell evaluation criteria and one or more first low mobility evaluation criteria, while the one or more second conditions include one or more second good serving cell evaluation criteria and one or more second low mobility evaluation criteria.

In some variants of these embodiments, the RLM/BFD relaxation information in the failure report can include the following:

• a first indication of whether the UE was performing the RLM in the serving cell according to the relaxed RLM measurement configuration, when the radio-related failure was detected; and

• when the first indication indicates that the UE was performing the RLM in the serving cell according to the relaxed RLM measurement configuration, a further indication of whether performing the RLM according to the relaxed RLM measurement configuration was based on meeting the first good serving cell criteria or based on meeting the first low mobility evaluation criteria.

In some variants of these embodiments, the RLM/BFD relaxation information in the failure report can include the following:

• a second indication of whether the UE was performing the BFD in the serving cell according to the relaxed BFD measurement configuration, when the radio-related failure was detected; and

• when the second indication indicates that the UE was performing the BFD in the serving cell according to the relaxed BFD measurement configuration, a further indication of whether performing the BFD according to the relaxed BFD measurement configuration was based on meeting the second good serving cell criteria or based on meeting the second low mobility evaluation criteria.

In some embodiments, the UE is configured first and second cell groups, with the serving cell being in the first cell group. The RLM/BFD relaxation configuration includes a first RLM relaxation configuration for the first cell group and/or a first BFD relaxation configuration for the first cell group. Additionally, the RLM/BFD relaxation configuration includes a second RLM relaxation configuration for the second cell group and/or a second BFD relaxation configuration for the second cell group.

In some of these embodiments, the RLM/BFD relaxation information in the failure report includes only the first RLM/BFD relaxation information for the first cell group, in which the radiorelated failure was detected. In other of these embodiments, the RLM/BFD relaxation information in the failure report includes both first RLM/BFD relaxation information for the first cell group and second RLM/BFD relaxation information for the second cell group. In some variants of these embodiments, the second RLM/BFD relaxation information for the second cell group includes one or more of the following:

• an indication of whether the UE was performing RLM in the second cell group according to the second RLM relaxation configuration, when the radio-related failure was detected in the serving cell of the first cell group;

• at least a portion of the second RLM relaxation configuration;

• a duration that the UE had been performing RLM in the second cell group according to the second RLM relaxation configuration, when the radio-related failure was detected in the serving cell of the first cell group;

• an indication of one or more conditions that triggered the UE to perform RLM in the second cell group according to the second RLM relaxation configuration;

• an indication of whether the UE was performing BFD in the second cell group according to the second BFD relaxation configuration, when the radio-related failure was detected in the serving cell of the first cell group;

• at least a portion of the second BFD relaxation configuration;

• a duration that the UE had been performing BFD in the second cell group according to the second BFD relaxation configuration, when the radio-related failure was detected in the serving cell of the first cell group; and

• an indication of one or more conditions that triggered the UE to perform BFD in the second cell group according to the second BFD relaxation configuration.

In some embodiments, these exemplary methods can also include receiving, from the first RAN node or a second RAN node, an updated RLM/BFD relaxation configuration after sending the failure report. In some embodiments, the radio-related failure is one of the following: a radio link failure (RLF), a handover failure (HOF), a master cell group (MCG) failure, or a secondary cell group (SCG) failure. In some embodiments, the failure report is one of the following messages: RLFReport, MCGFailur eInformation, or SCGFailur eInformation. Other embodiments include exemplary methods (e.g., procedures) for a RAN node configured to provide a serving cell to UEs. In general, these exemplary methods can be complementary to the exemplary methods for a UE summarized above.

These exemplary methods can include receiving, from a UE, a failure report about a radiorelated failure detected by the UE in the serving cell. The failure report includes RLM/BFD relaxation information pertaining to RLM and/or BFD being performed by the UE when the radio-related failure was detected. These exemplary methods can also include, based on the failure report, adjusting one or more parameters of an RLM/BFD relaxation configuration applicable in the serving cell.

In some embodiments, these exemplary methods can also include, before receiving the failure report, sending to the UE an RLM/BFD relaxation configuration that includes one or more of the following: one or more first conditions that must be met for the UE to perform RLM according to a relaxed RLM measurement configuration, and one or more second conditions that must be met for the UE to perform RLM according to a relaxed RLM measurement configuration. In some of these embodiments, the one or more parameters adjusted based on the failure report include the one or more first conditions and/or the one or more second conditions.

In some these embodiments, the one or more first conditions include one or more first good serving cell evaluation criteria and one or more first low mobility evaluation criteria, while the one or more second conditions include one or more second good serving cell evaluation criteria and one or more second low mobility evaluation criteria.

In general, the RLM/BFD relaxation information included in the received failure report can include any of the RLM/BFD relaxation information in the failure report sent by the UE (including all variants), as summarized above in relation to UE embodiments.

In some embodiments, these exemplary methods can also include sending to the UE an updated RLM/BFD relaxation configuration that includes the adjusted one or more parameters. In some embodiments, the radio-related failure is one of the following: RLF, HOF, MCG failure, or SCG failure. In some embodiments, the failure report is one of the following messages: RLF Report, MCGFailur eInformation, or SCGFailur eInfor mation.

In some embodiments, receiving the failure report and adjusting the one or more parameters is performed by a central unit (CU) of the RAN node, and these exemplary methods can also include the CU sending, to a distributed unit (DU) of the RAN node, an updated RLM/BFD relaxation configuration that includes the adjusted one or more parameters.

In other embodiments, receiving the failure report is performed by a CU of the RAN node and these exemplary methods can also include the CU forwarding the failure report to a DU of the RAN node. In such embodiments, adjusting the one or more parameters is performed by the DU of the RAN node.

Other embodiments include UEs (e.g., wireless devices) and RAN nodes (e.g., base stations, eNBs, gNBs, ng-eNBs, etc.) configured to perform operations corresponding to any of the exemplary methods described herein. Other embodiments include non-transitory, computer- readable media storing program instructions that, when executed by processing circuitry, configure such UEs and RAN nodes to perform operations corresponding to any of the exemplary methods described herein.

These and other embodiments described herein can provide various advantages, benefits, and/or solutions to problems. For example, receiving a UE failure report that includes RLM/BFD relaxation information enables a RAN node (or 0AM system) to determine whether BFD relaxation and/or RLM relaxation degraded the UE’s ability to detect the radio-related failure that triggered the failure report. Based on this determination, the RAN (or 0AM system) can optimize and/or adjust RLM/BFD relaxation parameters used for UEs, which can improve QoS/QoE experienced by users without sacrificing UE energy consumption improvements provided by RLM/BFD relaxation.

These and other objects, features, and advantages of embodiments of the present disclosure will become apparent upon reading the following Detailed Description in view of the Drawings briefly described below.

BRIEF DESCRIPTION OF THE DRAWINGS

Figures 1-2 illustrate two high-level views of an exemplary 5G/NR network architecture.

Figure 3 shows an exemplary configuration of NR user plane (UP) and control plane (CP) protocol stacks.

Figure 4 is a block diagram illustrating self-organization network (SON) functionality.

Figures 5-6 show signaling diagrams for procedures between a UE and a RAN node, according to various embodiments of the present disclosure.

Figure 7 (which includes Figures 7A-B) shows an exemplary ASN. l data structure for an RLF-Report-rl6 message or information element (IE) sent by a UE, according to various embodiments of the present disclosure.

Figures 8-9 show signaling diagrams for procedures between a UE and a RAN node, according to various embodiments of the present disclosure.

Figure 10 shows a flow diagram of an exemplary method for a UE (e.g., wireless device), according to various embodiments of the present disclosure.

Figure 11 shows a flow diagram of an exemplary method for a RAN node (e.g., base station, eNB, gNB, ng-eNB, etc.), according to various embodiments of the present disclosure. Figure 12 shows a communication system according to various embodiments of the present disclosure.

Figure 13 shows a UE according to various embodiments of the present disclosure.

Figure 14 shows a network node according to various embodiments of the present disclosure.

Figure 15 shows a host computing system according to various embodiments of the present disclosure.

Figure 16 is a block diagram of a virtualization environment in which functions implemented by some embodiments of the present disclosure may be virtualized.

Figure 17 illustrates communication between a host computing system, a network node, and a UE via multiple connections, at least one of which is wireless, according to various embodiments of the present disclosure.

DETAILED DESCRIPTION

Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein, the disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided as examples to convey the scope of the subject matter to those skilled in the art.

In general, all terms used herein are to be interpreted according to their ordinary meaning to a person of ordinary skill in the relevant technical field, unless a different meaning is expressly defined and/or implied from the context of use. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise or clearly implied from the context of use. The operations of any methods and/or procedures disclosed herein do not have to be performed in the exact order disclosed, unless an operation is explicitly described as following or preceding another operation and/or where it is implicit that an operation must follow or precede another operation. Any feature of any embodiment disclosed herein can apply to any other disclosed embodiment, as appropriate. Likewise, any advantage of any embodiment described herein can apply to any other disclosed embodiment, as appropriate.

Furthermore, the following terms are used throughout the description given below:

• Radio Access Node: As used herein, a “radio access node” (or equivalently “radio network node,” “radio access network node,” or “RAN node”) can be any node in a radio access network (RAN) that operates to wirelessly transmit and/or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., gNB in a 3 GPP 5G/NR network or an enhanced or eNB in a 3GPP LTE network), base station distributed components (e.g., CU and DU), a high-power or macro base station, a low-power base station (e.g., micro, pico, femto, or home base station, or the like), an integrated access backhaul (IAB) node, a transmission point (TP), a transmission reception point (TRP), a remote radio unit (RRU or RRH), and a relay node.

• Core Network Node: As used herein, a “core network node” is any type of node in a core network. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a serving gateway (SGW), a PDN Gateway (P-GW), a Policy and Charging Rules Function (PCRF), an access and mobility management function (AMF), a session management function (SMF), a user plane function (UPF), a Charging Function (CHF), a Policy Control Function (PCF), an Authentication Server Function (AUSF), a location management function (LMF), or the like.

• Wireless Device: As used herein, a “wireless device” (or “WD” for short) is any type of device that is capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other wireless devices. Communicating wirelessly can involve transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information through air. Unless otherwise noted, the term “wireless device” is used interchangeably herein with the term “user equipment” (or “UE” for short), with both of these terms having a different meaning than the term “network node”.

• Radio Node: As used herein, a “radio node” can be either a “radio access node” (or equivalent term) or a “wireless device.”

• Network Node: As used herein, a “network node” is any node that is either part of the radio access network (e.g., a radio access node or equivalent term) or of the core network (e.g., a core network node discussed above) of a cellular communications network. Functionally, a network node is equipment capable, configured, arranged, and/or operable to communicate directly or indirectly with a wireless device and/or with other network nodes or equipment in the cellular communications network, to enable and/or provide wireless access to the wireless device, and/or to perform other functions (e.g., administration) in the cellular communications network.

• Node: As used herein, the term “node” (without prefix) can be any type of node that can in or with a wireless network (including RAN and/or core network), including a radio access node (or equivalent term), core network node, or wireless device. However, the term “node” may be limited to a particular type (e.g., radio access node, IAB node) based on its specific characteristics in any given context. The above definitions are not meant to be exclusive. In other words, various ones of the above terms may be explained and/or described elsewhere in the present disclosure using the same or similar terminology. Nevertheless, to the extent that such other explanations and/or descriptions conflict with the above definitions, the above definitions should control.

Note that the description herein focuses on a 3 GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is generally used. However, the concepts disclosed herein are not limited to a 3GPP system. Other wireless systems, including without limitation Wide Band Code Division Multiple Access (WCDMA), Worldwide Interoperability for Microwave Access (WiMax), Ultra Mobile Broadband (UMB) and Global System for Mobile Communications (GSM), may also benefit from the concepts, principles, and/or embodiments described herein. Furthermore, although the term “cell” is used herein, it should be understood that (particularly with respect to 5G NR.) beams may be used instead of cells and, as such, concepts described herein apply equally to both cells and beams.

Figure 2 shows a high-level view of an exemplary 5G network architecture, including an NG-RAN (299) and a 5GC (298). As shown in the figure, the NG-RAN can include gNBs e.g., 210a, b) and ng-eNBs (e.g., 220a, b) that are interconnected via respective Xn interfaces. The gNBs and ng-eNBs are also connected via NG interfaces to the 5GC, more specifically to Access and Mobility Management Functions (AMFs, e.g., 230a, b) via respective NG-C interfaces and to User Plane Functions (UPFs, e.g., 240a, b) via respective NG-U interfaces. Moreover, the AMFs can communicate with one or more policy control functions (PCFs, e.g., 250a, b) and network exposure functions (NEFs, e.g., 260a, b).

Each gNB can support the NR radio interface including frequency division duplexing (FDD), time division duplexing (TDD), or a combination thereof. Each ng-eNB can support the LTE radio interface but unlike conventional LTE eNBs, ng-eNBs connect to the 5GC via the NG interface. Each of the gNBs and ng-eNBs can serve a geographic coverage area including one or more cells (e.g., 21 la-b and 221a-b). Depending on the cell in which it is located, a UE (205) can communicate with the gNB or ng-eNB serving that cell via the NR or LTE radio interface, respectively. Although Figure 2 shows gNBs and ng-eNBs separately, it is also possible that a single NG-RAN node provides both types of functionality.

5G/NR technology shares many similarities with LTE. For example, NR uses CP-OFDM (Cyclic Prefix Orthogonal Frequency Division Multiplexing) in the DL and both CP-OFDM and DFT-spread OFDM (DFT-S-OFDM) in the UL. As another example, in the time domain, NR DL and UL physical resources are organized into equal-sized 1-ms subframes. A subframe is further divided into multiple slots of equal duration, with each slot including multiple OFDM-based symbols. However, time-frequency resources can be configured much more flexibly for an NR cell than for an LTE cell. For example, rather than a fixed 15-kHz OFDM sub-carrier spacing (SCS) as in LTE, NR SCS can range from 15 to 240 kHz, with even greater SCS considered for future NR releases.

As briefly mentioned above, NR networks also provide coverage via “beams.” In general, a downlink (DL) “beam” is a coverage area of a network-transmitted RS that may be measured or monitored by a UE. In NR, for example, RS can include any of the following: synchronization signal/PBCH block (SSB), channel state information RS (CSLRS), tertiary reference signals (or any other sync signal), positioning RS (PRS), demodulation RS (DMRS), phase-tracking reference signals (PTRS), etc. In general, SSB is available to all UEs regardless of the state of their connection with the network, while other RS (e.g., CSLRS, DM-RS, PTRS) are associated with specific UEs that have a network connection.

Figure 3 shows an exemplary configuration of NR user plane (UP) and control plane (CP) protocol stacks between a UE (310), a gNB (320), and an AMF (330), such as those shown in Figures 1-2. The Physical (PHY), Medium Access Control (MAC), Radio Link Control (RLC), and Packet Data Convergence Protocol (PDCP) layers between the UE and the gNB are common to UP and CP. The PDCP layer provides ciphering/deciphering, integrity protection, sequence numbering, reordering, and duplicate detection for both CP and UP. In addition, PDCP provides header compression and retransmission for UP data.

On the UP side, Internet protocol (IP) packets arrive to the PDCP layer as service data units (SDUs), and PDCP creates protocol data units (PDUs) to deliver to RLC. The Service Data Adaptation Protocol (SDAP) layer handles quality-of-service (QoS) including mapping between QoS flows and Data Radio Bearers (DRBs) and marking QoS flow identifiers (QFI) in UL and DL packets. The RLC layer transfers PDCP PDUs to the MAC through logical channels (LCH). RLC provides error detection/correction, concatenation, segmentation/reassembly, sequence numbering, reordering of data transferred to/from the upper layers. The MAC layer provides mapping between LCHs and PHY transport channels, LCH prioritization, multiplexing into or demultiplexing from transport blocks (TBs), hybrid ARQ (HARQ) error correction, and dynamic scheduling (on gNB side). The PHY layer provides transport channel services to the MAC layer and handles transfer over the NR radio interface, e.g., via modulation, coding, antenna mapping, and beam forming.

On CP side, the non-access stratum (NAS) layer is between UE and AMF and handles UE/gNB authentication, mobility management, and security control. The RRC layer sits below NAS in the UE but terminates in the gNB rather than the AMF. RRC controls communications between UE and gNB at the radio interface as well as the mobility of a UE between cells in the NG-RAN. RRC also broadcasts system information (SI) and performs establishment, configuration, maintenance, and release of DRBs and Signaling Radio Bearers (SRBs) and used by UEs. Additionally, RRC controls addition, modification, and release of carrier aggregation (CA) and dual -connectivity (DC) configurations for UEs. RRC also performs various security functions such as key management.

After a UE is powered ON it will be in the RRC IDLE state until an RRC connection is established with the network, at which time the UE will transition to RRC_CONNECTED state (e.g, where data transfer can occur). The UE returns to RRC IDLE after the connection with the network is released. In RRC IDLE state, the UE’s radio is active on a discontinuous reception (DRX) schedule configured by upper layers. During DRX active periods (also referred to as “DRX On durations'’), an RRC IDLE, UE receives SI broadcast in the cell where the UE is camping, performs measurements of neighbor cells to support cell reselection, and monitors a paging channel on PDCCH for pages from 5GC via gNB. An NR UE in RRC IDLE state is not known to the gNB serving the cell where the UE is camping. However, NR RRC includes an RRC_INACTIVE state in which a UE is known (e.g., via UE context) by the serving gNB. RRC INACTIVE has some properties similar to a “suspended” condition used in LTE.

3 GPP Rel-12 introduced LTE dual connectivity (DC) in which a UE can be connected to two network nodes simultaneously, thereby improving connection robustness and/or capacity. In LTE DC, these two network nodes are referred to as “Master eNB” (MeNB) and “Secondary eNB” (SeNB), or more generally as master node (MN) and secondary node (SN). More specifically, a UE is configured with a Master Cell Group (MCG) associated with the MN and a Secondary Cell Group (SCG) associated with the SN. 3GPP TR 38.804 (vl4.0.0) describes various exemplary DC scenarios or configurations in which the MN and SN can apply NR, LTE, or both.

Each of these groups of serving cells include one MAC entity, a set of logical channels with associated RLC entities, a primary cell (PCell or PSCell), and optionally one or more secondary cells (SCells). The term “Special Cell” (or “SpCell” for short) refers to the PCell of the MCG or the PSCell of the SCG depending on whether the UE’s MAC entity is associated with the MCG or the SCG, respectively. In non-DC operation (e.g., carrier aggregation), SpCell refers to the PCell. An SpCell is always activated and supports physical uplink control channel (PUCCH) transmission and contention-based random access by UEs.

Seamless mobility is a key feature of 3GPP radio access technologies (RATs). In general, a RAN (e.g., NG-RAN) configures a UE in RRC_CONNECTED state to perform and report radio resource management (RRM) measurements to assist network-controlled mobility decisions, such as for handover from a serving cell to a neighbor cell. Seamless handovers ensure that the UE moves around in the coverage area of different cells without excessive interruption to data transmission. However, there will be scenarios when the network fails to handover the UE to the “correct” neighbor cell in time, which can cause the UE will declare radio link failure (RLF) or handover failure (HOF).

A UE typically triggers an internal RLF procedure when something unexpected happens in any of these mobility-related procedures. The RLF procedure involves interactions between RRC and lower layer protocols such as PHY (or LI), MAC, RLC, etc. including radio link monitoring (RLM) on LI.

The principle of RLM is similar in LTE and NR. In general, the UE monitors link quality of the UE’s serving cell and uses that information to decide whether the UE is in-sync (IS) or out- of-sync (OOS) with respect to that serving cell. If RLM (i.e., by Ll/PHY) indicates number of consecutive OOS conditions to the RRC layer, then RRC starts an RLF procedure and declares RLF after expiry of a timer (e.g., T310). The LI RLM procedure is carried out by comparing the estimated measurements to some targets Qout and Qin, which correspond to block error rates (BLERs) of hypothetical transmissions from the serving cell. Exemplary values of Qout and Qin are 10% and 2%, respectively. In NR, the network can define RS type (e.g., CSLRS and/or SSB), exact resources to be monitored, and the BLER target for IS and OOS indications.

In case of handover failure (HOF) and RLF, the UE may take autonomous actions such as selecting a cell and initiating reestablishment to remain reachable by the network. In general, a UE declares RLF only when the UE realizes that there is no reliable radio link available between itself and the network, which can result in poor user experience. Also, reestablishing the connection requires signaling with a newly selected cell (e.g., random access procedure, exchanging various RRC messages, etc.), which introduces latency until the UE can again reliably transmit and/or receive user data with the network. Potential causes for RLF include:

1) Radio link problem indicated by PHY (e.g., expiry of RLM-related timer T310);

2) Random access problem indicated by MAC entity;

3) Expiry of a measurement reporting timer (e.g., T312), due to not receiving a HO command from the network while the timer is running despite sending a measurement report;

4) Reaching a maximum number of RLC retransmissions;

5) Consistent LBT failures while operating in unlicensed spectrum; and

6) Failing a beam failure recovery (BFR) procedure.

On the other hand, HOF is caused by expiry of T304 timer while performing the handover to the target cell.

Since RLF leads to reestablishment in a new cell and degradation of UE/network performance and end-user experience, it is in the interest of the network to understand the reasons for UE RLF and to optimize mobility-related parameters (e.g., trigger conditions of measurement reports) to reduce, minimize, and/or avoid subsequent RLFs. Before Rel-9 mobility robustness optimizations (MRO), only the UE was aware of radio quality at the time of RLF, the actual reason for declaring RLF, etc.

An RLF reporting procedure was introduced as part of mobility robustness optimization (MRO) in LTE Rel-9. In this procedure, a UE logs relevant information at the time of RLF and later reports such information to the network via a target cell to which the UE ultimately connects (e.g., after reestablishment). The reported information can include RRM measurements of various neighbor cells prior to the mobility operation (e.g., handover). A corresponding RLF reporting procedure was introduced as part of MRO for NR Rel-16.

In this procedure, a UE logs relevant information at the time of RLF and later reports such information to the network via a target cell to which the UE ultimately connects (e.g., after reestablishment). The UE can store the RLF report in a UE variable call varRLF-Report and retains it in memory for up to 48 hours, after which it may discard the information.

When sending certain RRC messages such as RRCReconfigurationComplete, RRCReestablishmentComplete, RRCSetup-Complete, and RRCResumeComplete, the UE can indicate it has a stored RLF report by setting a rlf-InfoAvailable field to “true.” If the gNB serving the target cell wants to receive the RLF report, it sends the UE a UEInformationRequest message with a flag “rlf-ReportReq-rl6”. In response, the UE sends the gNB a UEInformationResponse message that includes the RLF report.

In general, UE-reported RLF information can include any of the following:

• Measurement quantities (RSRP, RSRQ) of the last serving cell (PCell).

• Measurement quantities of the neighbor cells in different frequencies of different RATs (e.g., EUTRA, UTRA, GERAN, CDMA2000).

• Measurement quantity (RS SI) associated to WLAN APs.

• Measurement quantity (RS SI) associated to Bluetooth beacons.

• Location information, if available (including location coordinates and velocity)

• Globally unique identity of the last serving cell, if available, otherwise the PCI and the carrier frequency of the last serving cell.

• Tracking area code of the PCell.

• Time elapsed since the last reception of the ‘Handover command’ message.

• C-RNTI used in the previous serving cell.

• Whether or not the UE was configured with a DRB having QCI = 1.

Based on a UE RLF report and knowledge of the cell in which the UE reestablished its connection, the RAN node serving the UE’s original source cell can deduce whether the RLF was due to a coverage hole or handover-related parameter configurations. If the latter case, the RAN node serving the UE’s original source cell can also classify the handover-related failure as too- early, too-late, or wrong-cell. These classes are described in more detail below.

The RAN node can classify a handover failure as “too late handover” when the original source cell fails to send the UE a command to handover to a particular target cell and if the UE ultimately reestablishes itself in this same target cell (i.e., post RLF). An example corrective action by the RAN node serving the UE’s original source cell is to initiate handovers towards this target cell slightly earlier, such as by decreasing the cell individual offset (CIO) towards the target cell. Note that CIO controls when the UE sends the RAN node an event-triggered measurement report that causes the RAN node to make a handover decision.

The RAN node can classify a handover failure as ‘too early handover’ when the original source cell successfully sends the UE a command to handover to a particular target cell but the UE fails to perform RA towards this target cell. An example corrective action by the RAN node serving the UE’s original source cell is to initiate handovers towards this target cell slightly later, such as by increasing CIO to cause the UE to send the event-triggered measurement report slightly later.

The RAN node can classify a handover failure as “wrong cell handover” when the original serving cell intends to perform the handover for this UE towards a particular target cell but the UE instead declares RLF and reestablishes its connection in a different cell. Example corrective actions by the RAN node serving the UE’s original source cell include initiating the UE measurement reporting procedure that leads to handover towards the target cell slightly later (e.g., by decreasing CIO for that cell) or initiating the handover towards the other cell in which the UE reestablished its connection slightly earlier (e.g., by increasing CIO for that cell).

NR Rel-15 introduced beam failure detection (BFD) and beam failure recovery (BFR). The serving RAN node configures a UE with BFD reference signals (e.g., SSB or CSLRS) to be monitored, and the UE declares beam failure when a quantity of beam failure indications from LI reaches a configured threshold before a configured timer expires. After BFD, the UE initiates a RA procedure in the serving cell and selects a suitable beam to perform BFR. In a multi-beam serving cell, RLF occurs when the UE is unable to find any suitable beam within the serving cell to recover the UE’s failed connection. In contrast, RLF is prevented by the UE’s successful BFR to another beam in the same cell.

3GPP TS 38.331 (vl7.1.0) specifies that a UE can be configured to relax its RLM/BFD procedures for the purpose of reducing UE energy consumption (also referred to as “energy saving”), with the measurement relaxation parameters specified in 3GPP TS 38.133 (vl7.6.0). In particular, the UE can perform relaxed RLM/BFD measurements only when the UE meets certain relaxation criteria (e.g., low mobility state and/or good serving cell quality) configured by the network.

For example, the relaxed RLM/BFD measurement criterion for an RRC CONNECTED UE with low mobility is fulfilled when (SS-RSRPRef - SS-RSRP) < SSearchDeltaP-Connected, where SS-RSRPRef is the reference L3 RSRP measurement of SSB (dB) that is set according to 3GPP TS 38.331 (vl7.1.0) section 5.17.3.1; SS-RSRP is the current L3 RSRP measurement of SSB (dB); and SSearchDeltaP-Connected is a parameter set by the RAN in the low mobility relaxation configuration.

As another example, the relaxed RLM measurement criterion for an RRC CONNECTED UE with good serving cell quality is evaluated after receiving a configuration for good serving cell quality and is met when the DL radio quality on the configured RLM-RS resource is better than the threshold Qin+XdB, wherein Qin is specified in 3GPP TS 38.331 (vl7.1.0) section 8.1 and X is the parameter offset set by the RAN in the goodServingCellEvaluationREM portion of the relaxation configuration.

As another example, the relaxed BFD measurement criterion for an RRC CONNECTED UE with good serving cell quality is evaluated after receiving a configuration for good serving cell quality and is met when the DL radio quality on the configured BFD-RS resource is better than the threshold Qin+XdB, wherein Qin is specified in 3GPP TS 38.331 (vl7.1.0) section 8.1 and X is the parameter offset set by the RAN in the goodServingCellEvaluationBFD portion of the relaxation configuration.

A UE reports whether it is in relaxation state for RLM and/or BFD in a UEAssistancelnformation RRC message. UE reporting of relaxation state information is controlled by respective prohibit timers, specifically rlm-RelaxtionReportingProhibitTimer for RLM relaxation state reporting and bfd-RelaxtionReportingProhibitTimer for BFD relaxation state reporting.

The RLM/BFD relaxation parameters used by the network (i.e., provided to UEs) can be determined using Self-Organizing Network (SON) functionality. A primary goal of SON functionality is to make planning, configuration, management, optimization, and healing of RANs simpler and faster. SON functionality and behavior has been defined and specified in by organizations such as 3GPP and NGMN (Next Generation Mobile Networks). Figure 4 is a high- level diagram illustrating 3GPP’s division of SON functionality into a self-configuration process and a self-optimization process.

Self-configuration is a pre-operational process in which newly deployed RAN nodes (e.g., eNBs or gNBs) in a pre-operational state are configured by automatic installation procedures to get the necessary basic configuration for system operation. Pre-operational state generally refers to the time when the node is powered up and has backbone connectivity until the node’s RF transmitter is switched on. Self-configuration operations in pre-operational state include (A) basic setup and (B) initial radio configuration, which include the following sub-operations shown in Figure 4:

• (a-1) Configuration of IP address and detection of operations administration and maintenance (0AM);

• (a-2) Authentication of RAN node;

• (a-3) Associate to access gateway (aGW);

• (a-4) Downloading of RAN node software (SW) and operational parameters;

• (b-1) Neighbor list configuration; and

• (b-2) Coverage/capacity-related parameter configuration.

Self-optimization is a process in which UE and network measurements are used to autotune the network. This occurs when the nodes are in operational state, which generally refers to when a node’s RF transmitter interface is switched on. Self-configuration operations include optimization and adaptation, which includes the following sub-operations shown in Figure 4:

• (c-1) Neighbor list optimization; and

• (c-2) Coverage/capacity control.

Self-configuration and self-optimization features for LTE networks are described in 3 GPP TS 36.300 (vl6.5.0) section 22.2. These include dynamic configuration, automatic neighbor relations (ANR), mobility load balancing (MLB), mobility robustness optimization (MRO), RACH optimization, and support for energy savings.

MLB involves coordination between two or more RAN nodes to optimize the traffic loads of their respective cells, thereby enabling a better use of radio resources available in a geographic area among served UEs. MLB can involve load-based handover of UEs between cells served by different nodes, thereby achieving “load balancing”.

CCO involves coordination between two or more RAN nodes to optimize the coverage and capacity offered by their respective cells. For example, a reduced coverage and/or capacity in a cell served by a first RAN node can be compensated by an increase in the coverage and/or capacity of neighboring cell served by a second RAN node.

Mobility settings change involves two RAN nodes negotiating a mutually agreeable value for a parameter that triggers UE handover (or other mobility operation) between neighbor cells. This parameter effectively defines a “virtual cell border” experienced by UEs based on their measurements and/or assessments, e.g., of quality and/or strength of reference signals received from the respective cells. For example, a setting change for a handover trigger parameter can expand or shrink the UE’s observed coverage area of a serving cell, thereby causing the UE to request a handover to a neighbor cell having a higher measured signal strength and/or quality.

However, improper SON configuration of RLM/BDF relaxation parameters can negatively impact UE performance. For example, a UE may experience bad radio coverage but does not declare RLF early enough due to relaxed RLM/BFD measurements. Because the UE operates in bad coverage conditions for a longer duration, the UE’s network quality of service (QoS) will be degraded, as will the end user’s QoE for applications/ services running on the UE.

Similarly, the UE may not perform BFR early enough due to relaxed RLM/BFD measurements, which can lead to declaring RLF. Put differently, a timely BFR can prevent the UE from experiencing a subsequent RLF, but the relaxed RLM/BFD measurements removes this possibility.

Accordingly, embodiments of the present disclosure provide flexible and efficient techniques whereby a UE that experiences a radio-related failure (e.g., RLF, HOF, MCG failure, SCG failure) in a serving cell logs a failure report (e.g., RLFReport, MCGFailur eInformation, SCGFailur eInformation, etc.) that includes RLM/BFD relaxation information, such as the UE’s current relaxation configuration at time of the failure and whether such configuration was applied at time of the failure. The UE can then send this failure report to a RAN node serving a cell to which the UE successfully connected after the radio-related failure.

Other embodiments include techniques whereby a RAN node receives a failure report including such information, and uses the included information to optimize and/or adjust RLM/BFD relaxation parameters used for UEs being served by the RAN node.

Embodiments of the present disclosure can provide various advantages, benefits, and/or solutions to problems. For example, receiving a UE failure report that includes RLM/BFD relaxation information enables a RAN node (or OAM system) to determine whether BFD relaxation and/or RLM relaxation degraded the UE’s ability to detect the radio-related failure (e.g., RLF, HOF, MCG failure, SCG failure) that triggered the failure report. Based on this determination, the RAN (or OAM system) can optimize and/or adjust RLM/BFD relaxation parameters used for UEs, which can improve QoS/QoE experienced by users without sacrificing UE energy consumption improvements provided by RLM/BFD relaxation.

Figure 5 shows a signaling diagram for a procedure between a UE (520) and a RAN node (510), according to various embodiments of the present disclosure. Initially, the RAN node provides the UE with RLM/BFD relaxation parameters, which may be in the form of RLM/BFD relaxation configuration(s). Subsequently, the UE declares a radio-related failure (e.g., RLF, HOF, etc. as discussed above) and logs a failure report. The failure report can include one or more of the following RLM/BFD relaxation information: • an indication of whether an RLM relaxation configuration was being used (i.e., had been “applied” such that relaxed RLM measurements were being performed) in the cell where the failure was detected, at the time when the failure was detected;

• at least a portion of the RLM relaxation configuration being used, e.g., a configuration for low mobility detection, a configuration for good serving cell evaluation, a configuration for rlm-RelaxtionReportingProhibitTimep

• a duration that the RLM relaxation configuration had been in use (i.e., upon meeting the condition(s) for relaxation) when the radio-related failure was detected;

• an indication of whether a BFD relaxation configuration was being used (i.e., had been “applied” such that relaxed BFD measurements were being performed) in the cell where the failure was detected, at the time when the failure was detected;

• at least a portion of the BFD relaxation configuration being used, e.g., a configuration for low mobility evaluation, a configuration for good serving cell BFD evaluation, a configuration for bfd-RelaxtionReportingProhibitTimep

• a duration that the BFD relaxation configuration had been in use (i.e., upon meeting the condition(s) for relaxation) when the radio-related failure was detected;

• an indication of whether RLM and/or BFD relaxation activation was due to detection of low mobility based on the configuration for low mobility detection;

• an indication of whether RLM and/or BFD relaxation activation was due to detection of good serving cell quality based on the configuration for good serving cell evaluation;

• an indication of whether an RLM relaxation configuration was being used in the PCell of a second cell group (e.g., SCG), at the time when the failure was detected in the PCell of a first cell group (e.g., MCG);

• at least a portion of the RLM relaxation configuration being used in the PCell of the second cell group, e.g., a configuration for low mobility detection, a configuration for good serving cell evaluation, a configuration for rlm-RelaxtionReportingProhibitTimep

• a duration that the RLM relaxation configuration had been in use in the PCell of the second cell group when the radio-related failure was detected in the PCell of the first cell group;

• an indication of whether RLM relaxation activation was due to detection of low mobility based on the configuration for low mobility detection applied in the PCell of the second cell group;

• an indication of whether a BFD relaxation configuration was in use in the PCell of a second cell group (e.g., SCG), at the time when the failure was detected in the PCell of a first cell group (e.g., MCG); • at least a portion of the BFD relaxation configuration being used in the PCell of the second cell group, e.g., a configuration for low mobility detection, a configuration for good serving cell evaluation, a configuration for rlm-RelaxtionReportingProhibitTimer

• a duration that the BFD relaxation configuration had been in use in the PCell of the second cell group when the radio-related failure was detected in the PCell of the first cell group;

• an indication of whether BFD relaxation activation was due to detection of low mobility based on the configuration for low mobility detection applied in the PCell of the second cell group;

• a duration between the UE’s most recent message (e.g., UEAssistancelnformation) indicating whether BFD/RLM relaxation was in use and detecting the radio-related failure;

• a duration between exiting RLM and BFD relaxation in the cell where the failure was detected and detecting the radio-related failure (i.e., when neither RLM nor BFD relaxation was applied when the failure was detected).

After logging this information, the UE can send the failure report to the RAN node. Note that although Figure 5 shows the same RAN node sending the RLM/BFD relaxation parameters and receiving the failure report, it is possible that the UE sends the failure report to a different RAN node. This may be the case, for example, if the UE re-established its connection to the RAN in a target cell served by a different RAN node.

In some embodiments, the logged information can be cell group specific, e.g., for MCG if the failure was detected in the MCG or for SCG if the failure was detected in the SCG. In other embodiments, the logged information can be non-cell group specific, e.g., for both MCG and SCG irrespective of whether the failure was detected in MCG or SCG. In such embodiments, separate information can be provided for the MCG and the SCG (e.g., in different IES).

Upon receiving the failure report from the UE, the RAN node can analyze the included RLM/BFD relaxation information and use it to adjust and/or optimize RLM/BFD relaxation parameters used for UEs being served by the RAN node. In some embodiments, the RAN node may base the adjustments and/or optimizations on failure reports from multiple UEs.

Figure 6 shows a signaling diagram for a procedure between a UE (620) and a RAN node (610), according to various embodiments of the present disclosure. Initially, the UE obtains RLM/BFD relaxation parameters, which may be in the form of RLM/BFD relaxation configuration(s). For example, the UE may obtain these from the RAN node, from another RAN node, from the CN, etc. Subsequently, the UE and RAN node perform DL and UL communication via the serving cell. At some point, the UE determines to apply RLM and/or BFD relaxation based on RLM/BFD relaxation configuration. For example, the UE may detect good serving cell conditions based on good serving cell evaluation criteria included in the RLM/BFD relaxation configuration. Alternately, the UE may detect low mobility conditions based on low mobility detection criteria included in the RLM/BFD relaxation configuration.

While performing RLM/BFD based on the configured relaxation parameters, the UE detects or declares a radio-related failure, such as RLF, HOF, MCG failure, SCG failure, etc. The UE logs a failure report about the radio-related failure and includes therein any of the UE declares a radio-related failure (e.g., RLF, HOF, etc. as discussed above) and logs a failure report. The failure report can include any of the RLM/BFD relaxation information discussed above. The failure report can be in a form and/or message that corresponds to the actual radiorelated failure, e.g., RLFReport, SCGFailur eInformation, MCGFailur eInformation, etc.

In some embodiments, when the radio-related failure (e.g., RLF) occurs in the MCG and the UE is configured to perform fast MCG failure recovery by transmitting the MCGFailur eInformation message via SN, the UE can include indications of its RLM/BFD relaxation status and configurations for the PSCell. This would aid the network in understanding whether MCG failure recovery took a long time, failed because of the RLM/BFD relaxation configuration on the PSCell, or failed for other reason(s).

In some embodiments, a UE in DC may have separate RLM/BFD relaxation configurations for its PCell and its PSCell. In some of these embodiments, the UE may include in the failure report separate RLM/BFD relaxation information for the PCell and the PSCell. In different variants, the UE may include in the failure report the same or different types of RLM/BFD relaxation information (e.g., as listed above) for the PCell and the PSCell. The inclusion of separate RLM/BFD relaxation information for PCell (or MCG) and PSCell (or SCG) may be independent of the cell group in which the failure was detected.

In other of these embodiments, the UE only includes in the failure report the RLM/BFD relaxation information pertaining to the cell group in which the radio-related failure was detected. For example, if the failure was detected in the MCG, the UE includes RLM/BFD relaxation information pertaining to the MCG but does not include RLM/BFD relaxation information pertaining to the SCG.

Some embodiments can be realized as messages in protocols described in 3GPP specifications. For example, Figures 7A-B show an exemplary ASN. l data structure for an RRC RLF-Report-rl6 message or information element (IE) sent by a UE, according to some embodiments of the present disclosure. This message or IE includes the following parameters or fields that relate to various embodiments described above:

• BFD-relaxation-rl8, which is an optional field. Presence indicates that BFD relaxation was applied in the cell where the failure was detected, at the time when the failure was detected, while absence indicates opposite. • BFD-relaxationConfiguration-r 18, which is an optional field. If present, it includes a GoodServingCellEvaluation-rl8 data structure that provides the configuration for good serving cell evaluation used by the UE for determining whether to apply BFD relaxation.

• time-since-BFD-relaxation-rl8, which indicates an elapsed time between the UE applying the BFD relaxation configuration and detecting the radio-related failure

• RLM-relaxation-rl8, which is an optional field. Its presence indicates that RLM relaxation was applied in the cell where the failure was detected, at the time when the failure was detected, while absence indicates opposite.

• RLM-relaxationConfiguration-rl8, which is an optional field. If present, it includes a GoodServingCellEvaluation-rl8 data structure (further defined in Figure 7B) that provides the configuration for good serving cell evaluation used by the UE for determining whether to apply RLM relaxation.

• time-since-RLM-relaxation-rl8, which indicates an elapsed time between the UE applying the RLM relaxation configuration and detecting the radio-related failure.

• lowMobility-relaxation-rl8, which is optional. Presence indicates that the RLM/BFD relaxation was applied by the UE at the time when the failure was detected, based on UE detection of low mobility according to the configuration for low mobility detection. Absence indicates opposite.

• lowMobility-relaxationConfiguration-rl8, which is an optional field. If present, it indicates the configuration for low mobility detection used by the UE, i.e., for entering low-mobility RLM/BFD relaxation.

Upon receiving the failure report from the UE, the RAN node can analyze the included RLM/BFD relaxation information and use it to adjust and/or optimize RLM/BFD relaxation parameters for UEs being served by the RAN node. In some embodiments, the RAN node may base the adjustments and/or optimizations on failure reports from multiple UEs.

Figure 8 shows a signaling diagram for a procedure between a UE (820) and a RAN node (810), according to various embodiments of the present disclosure. In particular, the RAN node includes a CU (811) and a DU (812) such as described above in relation to Figure 1. The UE sends a failure report including RLM/BFD relaxation information (e.g., any of the above-listed items) to the RAN node CU, e.g., as an RRC message. Upon receiving the failure report from the UE, the RAN node CU analyzes the included RLM/BFD relaxation information and uses it to adjust and/or optimize RLM/BFD relaxation parameters. The RAN node CU sends these RLM/BFD relaxation parameters to the RAN node DU, which applies them to UEs that it serves in one or more cells. Figure 9 shows a signaling diagram for a procedure between a UE (920) and a RAN node (910), according to various embodiments of the present disclosure. In particular, the RAN node includes a CU (911) and a DU (912) such as described above in relation to Figure 1. The UE sends a failure report including RLM/BFD relaxation information (e.g., any of the above-listed items) to the RAN node CU, e.g., as an RRC message. Upon receiving the failure report from the UE, the RAN node CU forwards it to the RAN node DU, which analyzes the included RLM/BFD relaxation information and uses it to adjust and/or optimize RLM/BFD relaxation parameters. The RAN node DU then applies these RLM/BFD relaxation parameters to UEs that it serves in one or more cells.

As one example, if the failure report indicates that RLM/BFD relaxation was applied due to UE detection of low mobility based on corresponding criteria in the RLM/BFD relaxation configuration, then the RAN node CU (or DU) may adjust the low mobility detection criteria to reduce the likelihood of RLM/BFD relaxation being applied when the UE detects a radio-related failure.

As another example, if the failure report indicates that RLM/BFD relaxation was applied due to UE detection of good cell conditions based on corresponding criteria in the RLM/BFD relaxation configuration (e.g., GoodServingCellEvaluation), then the RAN node CU (or DU) may adjust the GoodServingCellEvaluation configurations to reduce the likelihood of RLM/BFD relaxation being applied when the UE detects a radio-related failure.

Various features of the embodiments described above correspond to various operations illustrated in Figures 10-11, which show exemplary methods (e.g., procedures) for a UE and a RAN node, respectively. In other words, various features of the operations described below correspond to various embodiments described above. Furthermore, the exemplary methods shown in Figures 10-11 can be used cooperatively to provide various benefits, advantages, and/or solutions to problems described herein. Although Figures 10-11 show specific blocks in particular orders, the operations of the exemplary methods can be performed in different orders than shown and can be combined and/or divided into blocks having different functionality than shown. Optional blocks or operations are indicated by dashed lines.

In particular, Figure 10 shows an exemplary method (e.g., procedure) for a UE configured for operation in a RAN, according to various embodiments of the present disclosure. The exemplary method can be performed by a UE (e.g., wireless device) such as described elsewhere herein.

The exemplary method can include the operations of block 1020, where the UE can perform RLM and/or BFD in a serving cell provided by a first RAN node. The exemplary method can also include the operations of block 1030, where the UE can detect a radio-related failure in the serving cell based on performing RLM and/or BFD (e.g., in block 1020). The exemplary method can also include the operations of block 1040, where the UE can send, to the first RAN node or to a second RAN node, a failure report including RLM/BFD relaxation information pertaining to the RLM and/or the BFD being performed when the radio-related failure was detected.

In some embodiments, the exemplary method can also include the operations of block 1010, where before performing RLM and BFD in the serving cell, the UE can receive from the first RAN node an RLM/BFD relaxation configuration that includes one or more of the following: one or more first conditions that must be met to perform RLM according to a relaxed RLM measurement configuration, and one or more second conditions that must be met to perform BFD according to a relaxed BFD measurement configuration.

In some of these embodiments, performing RLM in the serving cell in block 1020 can include the following operations, labelled with corresponding sub-block numbers:

• (1021) determining whether the one or more first conditions are met;

• (1022) performing RLM in the serving cell according to the relaxed RLM measurement configuration when it is determined that the one or more first conditions are met;

• (1023) performing RLM in the serving cell according to a normal or non-relaxed RLM measurement configuration when it is determined that the one or more first conditions are not met;

In some of these embodiments, performing BFD in the serving cell in block 1020 can include the following operations, labelled with corresponding sub-block numbers:

• (1024) determining whether the one or more second conditions are met;

• (1025) performing BFD in the serving cell according to the relaxed BFD measurement configuration when it is determined that the one or more second conditions are met; and

• (1026) performing BFD in the serving cell according to a normal or non-relaxed BFD measurement configuration when it is determined that the one or more second conditions are not met.

In some of these embodiments, the RLM/BFD relaxation information in the failure report includes one or more the following:

• a first indication of whether the UE was performing the RLM in the serving cell according to the relaxed RLM measurement configuration, when the radio-related failure was detected;

• at least a portion of the first conditions;

• a duration that the UE had been performing RLM in the serving cell according to the relaxed RLM measurement configuration, when the radio-related failure was detected; • a second indication of whether the UE was performing the BFD in the serving cell according to the relaxed BFD measurement configuration, when the radio-related failure was detected;

• at least a portion of the second conditions; and

• a duration that the UE had been performing the BFD in the serving cell according to the relaxed BFD measurement configuration, when the radio-related failure was detected.

In some of these embodiments, the one or more first conditions include one or more first good serving cell evaluation criteria and one or more first low mobility evaluation criteria, while the one or more second conditions include one or more second good serving cell evaluation criteria and one or more second low mobility evaluation criteria. Examples of these criteria were discussed above in relation to Figure 7.

In some variants of these embodiments, the RLM/BFD relaxation information in the failure report can include the following:

• a first indication of whether the UE was performing the RLM in the serving cell according to the relaxed RLM measurement configuration, when the radio-related failure was detected; and

• when the first indication indicates that the UE was performing the RLM in the serving cell according to the relaxed RLM measurement configuration, a further indication of whether performing the RLM according to the relaxed RLM measurement configuration was based on meeting the first good serving cell criteria or based on meeting the first low mobility evaluation criteria.

In some variants of these embodiments, the RLM/BFD relaxation information in the failure report can include the following:

• a second indication of whether the UE was performing the BFD in the serving cell according to the relaxed BFD measurement configuration, when the radio-related failure was detected; and

• when the second indication indicates that the UE was performing the BFD in the serving cell according to the relaxed BFD measurement configuration, a further indication of whether performing the BFD according to the relaxed BFD measurement configuration was based on meeting the second good serving cell criteria or based on meeting the second low mobility evaluation criteria.

In some embodiments, the UE is configured first and second cell groups, with the serving cell being in the first cell group. The RLM/BFD relaxation configuration includes a first RLM relaxation configuration for the first cell group and/or a first BFD relaxation configuration for the first cell group. Additionally, the RLM/BFD relaxation configuration includes a second RLM relaxation configuration for the second cell group and/or a second BFD relaxation configuration for the second cell group.

In some of these embodiments, the RLM/BFD relaxation information in the failure report includes only the first RLM/BFD relaxation information for the first cell group, in which the radiorelated failure was detected. In other of these embodiments, the RLM/BFD relaxation information in the failure report includes both first RLM/BFD relaxation information for the first cell group and second RLM/BFD relaxation information for the second cell group. In some variants of these embodiments, the second RLM/BFD relaxation information for the second cell group includes one or more of the following:

• an indication of whether the UE was performing RLM in the second cell group according to the second RLM relaxation configuration, when the radio-related failure was detected in the serving cell of the first cell group;

• at least a portion of the second RLM relaxation configuration;

• a duration that the UE had been performing RLM in the second cell group according to the second RLM relaxation configuration, when the radio-related failure was detected in the serving cell of the first cell group;

• an indication of one or more conditions that triggered the UE to perform RLM in the second cell group according to the second RLM relaxation configuration;

• an indication of whether the UE was performing BFD in the second cell group according to the second BFD relaxation configuration, when the radio-related failure was detected in the serving cell of the first cell group;

• at least a portion of the second BFD relaxation configuration;

• a duration that the UE had been performing BFD in the second cell group according to the second BFD relaxation configuration, when the radio-related failure was detected in the serving cell of the first cell group; and

• an indication of one or more conditions that triggered the UE to perform BFD in the second cell group according to the second BFD relaxation configuration.

In some embodiments, the exemplary method can also include the operations of block 1050, where the UE can receive, from the first RAN node or a second RAN node, an updated RLM/BFD relaxation configuration after sending the failure report.

In some embodiments, the radio-related failure is one of the following: a radio link failure (REF), a handover failure (HOF), a master cell group (MCG) failure, or a secondary cell group (SCG) failure. In some embodiments, the failure report is one of the following messages: RLE Report, MCGFailur eInformation, or SCGFailur eInfor mation.

In addition, Figure 11 shows an exemplary method (e.g., procedure) for a RAN node configured to provide a serving cell for UEs, according to various embodiments of the present disclosure. The exemplary method can be performed by a RAN node (e.g., base station, eNB, gNB, ng-eNB, etc.) such as described elsewhere herein.

The exemplary method can include the operations of block 1120, where the RAN node can receive, from a UE, a failure report about a radio-related failure detected by the UE in the serving cell. The failure report includes RLM/BFD relaxation information pertaining to RLM and/or BFD being performed by the UE when the radio-related failure was detected. The exemplary method can also include the operations of block 1140, where based on the failure report, the RAN node can adjust one or more parameters of an RLM/BFD relaxation applicable in the serving cell.

In some embodiments, the exemplary method can also include the operations of block 1110, where before receiving the failure report (e.g., in block 1120), the RAN node can send to the UE an RLM/BFD relaxation configuration that includes one or more of the following: one or more first conditions that must be met for the UE to perform RLM according to a relaxed RLM measurement configuration, and one or more second conditions that must be met for the UE to perform RLM according to a relaxed RLM measurement configuration. In some of these embodiments, the one or more parameters adjusted in block 1140 based on the failure report include the one or more first conditions and/or the one or more second conditions.

In general, the RLM/BFD relaxation information included in the failure report received in block 1120 can include any of the RLM/BFD relaxation information in the failure report sent by the UE (including all variants), as discussed above in relation to UE embodiments.

In some embodiments, the exemplary method can also include the operations of block 1150, where the RAN node can send to the UE an updated RLM/BFD relaxation configuration that includes the adjusted one or more parameters.

In some embodiments, the radio-related failure is one of the following: RLF, HOF, MCG failure, or SCG failure. In some embodiments, the failure report is one of the following messages: RLF Report, MCGFailur eInformation, or SCGFailur eInfor mation.

In some embodiments, receiving the failure report in block 1120 and adjusting the one or more parameters in block 1140 is performed by a central unit (CU) of the RAN node, and the exemplary method can also include the operations of block 1160, where the RAN node CU can send, to a distributed unit (DU) of the RAN node, an updated RLM/BFD relaxation configuration that includes the adjusted one or more parameters. Figure 8 shows an example of these embodiments.

In other embodiments, receiving the failure report in block 1120 is performed by a CU of the RAN node and the exemplary method can also include the operations of block 1130, where the CU can forward the failure report to a DU of the RAN node. In such embodiments, adjusting the one or more parameters in block 1140 is performed by the DU of the RAN node.

Although various embodiments are described above in terms of methods, techniques, and/or procedures, the person of ordinary skill will readily comprehend that such methods, techniques, and/or procedures can be embodied by various combinations of hardware and software in various systems, communication devices, computing devices, control devices, apparatuses, non-transitory computer-readable media, computer program products, etc.

Figure 12 shows an example of a communication system 1200 in accordance with some embodiments. In this example, communication system 1200 includes a telecommunication network 1202 that includes an access network 1204 (e.g., RAN) and a core network 1206, which includes one or more core network nodes 1208. Access network 1204 includes one or more access network nodes, such as network nodes 1210a-b (one or more of which may be generally referred to as network nodes 1210), or any other similar 3 GPP access node or non-3GPP access point. Network nodes 1210 facilitate direct or indirect connection of UEs, such as by connecting UEs 1212a-d (one or more of which may be generally referred to as UEs 1212) to core network 1206 over one or more wireless connections.

Example wireless communications over a wireless connection include transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, communication system 1200 may include any number of wired or wireless networks, network nodes, UEs, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections. Communication system 1200 may include and/or interface with any type of communication, telecommunication, data, cellular, radio network, and/or other similar type of system.

UEs 1212 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and/or operable to communicate wirelessly with network nodes 1210 and other communication devices. Similarly, network nodes 1210 are arranged, capable, configured, and/or operable to communicate directly or indirectly with UEs 1212 and/or with other network nodes or equipment in telecommunication network 1202 to enable and/or provide network access, such as wireless network access, and/or to perform other functions, such as administration in telecommunication network 1202.

In the depicted example, core network 1206 connects network nodes 1210 to one or more hosts, such as host 1216. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. Core network 1206 includes one or more core network nodes (e.g., 1208) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and/or hosts, such that the descriptions thereof are generally applicable to the corresponding components of core network node 1208. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and/or a User Plane Function (UPF).

Host 1216 may be under the ownership or control of a service provider other than an operator or provider of access network 1204 and/or telecommunication network 1202, and may be operated by the service provider or on behalf of the service provider. Host 1216 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio/video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

As a whole, communication system 1200 of Figure 12 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and/or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and/or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

In some examples, telecommunication network 1202 is a cellular network that implements 3 GPP standardized features. Accordingly, telecommunication network 1202 may support network slicing to provide different logical networks to different devices that are connected to telecommunication network 1202. For example, telecommunication network 1202 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and/or Massive Machine Type Communication (mMTC)/Massive loT services to yet further UEs.

In some examples, UEs 1212 are configured to transmit and/or receive information without direct human interaction. For instance, a UE may be designed to transmit information to access network 1204 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from access network 1204. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e., being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

In the example, hub 1214 communicates with access network 1204 to facilitate indirect communication between one or more UEs (e.g., UE 1212c and/or 1212d) and network nodes (e.g., network node 1210b). In some examples, hub 1214 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, hub 1214 may be a broadband router enabling access to core network 1206 for the UEs. As another example, hub 1214 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 1210, or by executable code, script, process, or other instructions in hub 1214. As another example, hub 1214 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, hub 1214 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, hub 1214 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which hub 1214 then provides to the UE either directly, after performing local processing, and/or after adding additional local content. In still another example, hub 1214 acts as a proxy server or orchestrator for the UEs, in particular in if one or more of the UEs are low energy loT devices.

Hub 1214 may have a constant/persistent or intermittent connection to network node 1210b. Hub 1214 may also allow for a different communication scheme and/or schedule between hub 1214 and UEs (e.g., UE 1212c and/or 1212d), and between hub 1214 and core network 1206. In other examples, hub 1214 is connected to core network 1206 and/or one or more UEs via a wired connection. Moreover, hub 1214 may be configured to connect to an M2M service provider over access network 1204 and/or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with network nodes 1210 while still connected via hub 1214 via a wired or wireless connection. In some embodiments, hub 1214 may be a dedicated hub - that is, a hub whose primary function is to route communications to/from the UEs from/to network node 1210b. In other embodiments, hub 1214 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 1210b, but which also can be a communication start and/or end point for certain data channels.

Figure 13 shows a UE 1300 in accordance with some embodiments. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customer-premise equipment (CPE), vehicle-mounted or vehicle embedded/integrated wireless device, etc. Other examples include any UE identified by 3 GPP, including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE.

A UE may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and/or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

UE 1300 includes processing circuitry 1302 that is operatively coupled via bus 1304 to input/output interface 1306, power source 1308, memory 1310, communication interface 1312, and/or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 13. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

Processing circuitry 1302 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in memory 1310. Processing circuitry 1302 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field- programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general -purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, processing circuitry 1302 may include multiple central processing units (CPUs).

In the example, input/output interface 1306 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and/or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into UE 1300. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

In some embodiments, power source 1308 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. Power source 1308 may further include power circuitry for delivering power from power source 1308 itself, and/or an external power source, to the various parts of UE 1300 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging power source 1308. Power circuitry may perform any formatting, converting, or other modification to the power from power source 1308 to make the power suitable for the respective components of UE 1300 to which power is supplied.

Memory 1310 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, memory 1310 includes one or more application programs 1314, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 1316. Memory 1310 may store, for use by UE 1300, any of a variety of various operating systems or combinations of operating systems.

Memory 1310 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and/or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ Memory 1310 may allow UE 1300 to access instructions, application programs and the like, stored on transitory or non- transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in memory 1310, which may be or comprise a device-readable storage medium.

Processing circuitry 1302 may be configured to communicate with an access network or other network using communication interface 1312. Communication interface 1312 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 1322. Communication interface 1312 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include transmitter 1318 and/or receiver 1320 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, transmitter 1318 and receiver 1320 may be coupled to one or more antennas (e.g., 1322) and may share circuit components, software or firmware, or alternatively be implemented separately.

In the illustrated embodiment, communication functions of communication interface 1312 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and/or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol/internet protocol (TCP/IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 1312, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., an alert is sent when moisture is detected), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door/window sensor, a flood/moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or Virtual Reality (VR), a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and/or software in dependence of the intended application of the loT device in addition to other components as described in relation to UE 1300 shown in Figure 13.

As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another UE and/or a network node. The UE may in this case be an M2M device, which may in a 3 GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation.

In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g., by controlling an actuator) to increase or decrease the drone’s speed. The first and/or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

Figure 14 shows a network node 1400 in accordance with some embodiments. Examples of network nodes include, but are not limited to, access points (e.g., radio access points) and base stations (e.g., radio base stations, Node Bs, eNBs, and gNBs).

Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units and/or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell/multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and/or Minimization of Drive Tests (MDTs).

Network node 1400 includes processing circuitry 1402, memory 1404, communication interface 1406, and power source 1408. Network node 1400 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which network node 1400 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, network node 1400 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 1404 for different RATs) and some components may be reused (e.g., a same antenna 1410 may be shared by different RATs). Network node 1400 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1400, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 1400.

Processing circuitry 1402 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in conjunction with other network node 1400 components, such as memory 1404, to provide network node 1400 functionality.

In some embodiments, processing circuitry 1402 includes a system on a chip (SOC). In some embodiments, processing circuitry 1402 includes one or more of radio frequency (RF) transceiver circuitry 1412 and baseband processing circuitry 1414. In some embodiments, RF transceiver circuitry 1412 and baseband processing circuitry 1414 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 1412 and baseband processing circuitry 1414 may be on the same chip or set of chips, boards, or units.

Memory 1404 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device-readable and/or computer-executable memory devices that store information, data, and/or instructions that may be used by processing circuitry 1402. Memory 1404 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and/or other instructions (collectively denoted computer program 1404a, which may be in the form of a computer program product) capable of being executed by processing circuitry 1402 and utilized by network node 1400. Memory 1404 may be used to store any calculations made by processing circuitry 1402 and/or any data received via communication interface 1406. In some embodiments, processing circuitry 1402 and memory 1404 is integrated. Communication interface 1406 is used in wired or wireless communication of signaling and/or data between a network node, access network, and/or UE. As illustrated, communication interface 1406 comprises port(s)/terminal(s) 1416 to send and receive data, for example to and from a network over a wired connection. Communication interface 1406 also includes radio frontend circuitry 1418 that may be coupled to, or in certain embodiments a part of, antenna 1410. Radio front-end circuitry 1418 comprises filters 1420 and amplifiers 1422. Radio front-end circuitry 1418 may be connected to antenna 1410 and processing circuitry 1402. The radio frontend circuitry may be configured to condition signals communicated between antenna 1410 and processing circuitry 1402. Radio front-end circuitry 1418 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. Radio front-end circuitry 1418 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1420 and/or amplifiers 1422. The radio signal may then be transmitted via antenna 1410. Similarly, when receiving data, antenna 1410 may collect radio signals which are then converted into digital data by radio front-end circuitry 1418. The digital data may be passed to processing circuitry 1402. In other embodiments, the communication interface may comprise different components and/or different combinations of components.

In certain alternative embodiments, network node 1400 does not include separate radio front-end circuitry 1418, instead, processing circuitry 1402 includes radio front-end circuitry and is connected to antenna 1410. Similarly, in some embodiments, all or some of RF transceiver circuitry 1412 is part of communication interface 1406. In still other embodiments, communication interface 1406 includes one or more ports or terminals 1416, radio front-end circuitry 1418, and RF transceiver circuitry 1412, as part of a radio unit (not shown), and communication interface 1406 communicates with baseband processing circuitry 1414, which is part of a digital unit (not shown).

Antenna 1410 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. Antenna 1410 may be coupled to radio front-end circuitry 1418 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In certain embodiments, antenna 1410 is separate from network node 1400 and connectable to network node 1400 through an interface or port.

Antenna 1410, communication interface 1406, and/or processing circuitry 1402 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by the network node. Any information, data and/or signals may be received from a UE, another network node and/or any other network equipment. Similarly, antenna 1410, communication interface 1406, and/or processing circuitry 1402 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and/or signals may be transmitted to a UE, another network node and/or any other network equipment.

Power source 1408 provides power to the various components of network node 1400 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). Power source 1408 may further comprise, or be coupled to, power management circuitry to supply the components of network node 1400 with power for performing the functionality described herein. For example, network node 1400 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of power source 1408. As a further example, power source 1408 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

Embodiments of network node 1400 may include additional components beyond those shown in Figure 14 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and/or any functionality necessary to support the subject matter described herein. For example, network node 1400 may include user interface equipment to allow input of information into network node 1400 and to allow output of information from network node 1400. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for network node 1400.

Figure 15 is a block diagram of a host 1500, which may be an embodiment of host 1216 of Figure 12, in accordance with various aspects described herein. As used herein, host 1500 may be or comprise various combinations hardware and/or software, including a standalone server, a blade server, a cloud-implemented server, a distributed server, a virtual machine, container, or processing resources in a server farm. Host 1500 may provide one or more services to one or more UEs.

Host 1500 includes processing circuitry 1502 that is operatively coupled via bus 1504 to input/ output interface 1506, network interface 1508, power source 1510, and memory 1512. Other components may be included in other embodiments. Features of these components may be substantially similar to those described with respect to the devices of previous figures, such as Figures 13 and 14, such that the descriptions thereof are generally applicable to the corresponding components of host 1500.

Memory 1512 may include one or more computer programs including one or more host application programs 1514 and data 1516, which may include user data, e.g., data generated by a UE for host 1500 or data generated by host 1500 for a UE. Embodiments of host 1500 may utilize only a subset or all of the components shown. Host application programs 1514 may be implemented in a container-based architecture and may provide support for video codecs (e.g., Versatile Video Coding (VVC), High Efficiency Video Coding (HEVC), Advanced Video Coding (AVC), MPEG, VP9) and audio codecs (e.g., FLAC, Advanced Audio Coding (AAC), MPEG, G.711), including transcoding for multiple different classes, types, or implementations of UEs (e.g., handsets, desktop computers, wearable display systems, heads-up display systems). Host application programs 1514 may also provide for user authentication and licensing checks and may periodically report health, routes, and content availability to a central node, such as a device in or on the edge of a core network. Accordingly, host 1500 may select and/or indicate a different host for over-the-top services for a UE. Host application programs 1514 may support various protocols, such as the HTTP Live Streaming (HLS) protocol, Real-Time Messaging Protocol (RTMP), Real- Time Streaming Protocol (RTSP), Dynamic Adaptive Streaming over HTTP (MPEG-DASH), etc.

Figure 16 is a block diagram illustrating a virtualization environment 1600 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 1600 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized.

Applications 1602 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in virtualization environment 1600 to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein.

Hardware 1604 includes processing circuitry, memory that stores software and/or instructions (collectively denoted computer program 1604a, which may be in the form of a computer program product) executable by hardware processing circuitry, and/or other hardware devices as described herein, such as a network interface, input/output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 1606 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 1608a-b (one or more of which may be generally referred to as VMs 1608), and/or perform any of the functions, features and/or benefits described in relation with some embodiments described herein. Virtualization layer 1606 may present a virtual operating platform that appears like networking hardware to the VMs 1608.

VMs 1608 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1606. Different embodiments of the instance of a virtual appliance 1602 may be implemented on one or more of VMs 1608, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

In the context of NFV, each VM 1608 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each VM 1608, and that part of hardware 1604 that executes that VM, be it hardware dedicated to that VM and/or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 1608 on top of the hardware 1604 and corresponds to application 1602.

Hardware 1604 may be implemented in a standalone network node with generic or specific components. Hardware 1604 may implement some functions via virtualization. Alternatively, hardware 1604 may be part of a larger cluster of hardware (e.g., such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 1610, which, among others, oversees lifecycle management of applications 1602. In some embodiments, hardware 1604 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 1612 which may alternatively be used for communication between hardware nodes and radio units.

Figure 17 shows a communication diagram of host 1702 communicating via network node 1704 with UE 1706 over a partially wireless connection in accordance with some embodiments. Example implementations, in accordance with various embodiments, of the UE (such as a UE 1212a of Figure 12 and/or UE 1300 of Figure 13), network node (such as network node 1210a of Figure 12 and/or network node 1400 of Figure 14), and host (such as host 1216 of Figure 12 and/or host 1500 of Figure 15) discussed in the preceding paragraphs will now be described with reference to Figure 17.

Like host 1500, embodiments of host 1702 include hardware, such as a communication interface, processing circuitry, and memory. Host 1702 also includes software, which is stored in or accessible by host 1702 and executable by the processing circuitry. The software includes a host application that may be operable to provide a service to a remote user, such as UE 1706 connecting via an over-the-top (OTT) connection 1750 extending between UE 1706 and host 1702. In providing the service to the remote user, a host application may provide user data which is transmitted using OTT connection 1750.

Network node 1704 includes hardware enabling it to communicate with host 1702 and UE 1706. Connection 1760 may be direct or pass through a core network (like core network 1206 of Figure 12) and/or one or more other intermediate networks, such as one or more public, private, or hosted networks. For example, an intermediate network may be a backbone network or the Internet.

UE 1706 includes hardware and software, which is stored in or accessible by UE 1706 and executable by the UE’s processing circuitry. The software includes a client application, such as a web browser or operator-specific “app” that may be operable to provide a service to a human or non-human user via UE 1706 with the support of host 1702. In host 1702, an executing host application may communicate with the executing client application via OTT connection 1750 terminating at UE 1706 and host 1702. In providing the service to the user, the UE's client application may receive request data from the host's host application and provide user data in response to the request data. OTT connection 1750 may transfer both the request data and the user data. The UE's client application may interact with the user to generate the user data that it provides to the host application through OTT connection 1750.

OTT connection 1750 may extend via a connection 1760 between host 1702 and network node 1704 and via a wireless connection 1770 between network node 1704 and UE 1706 to provide the connection between host 1702 and UE 1706. Connection 1760 and wireless connection 1770, over which OTT connection 1750 may be provided, have been drawn abstractly to illustrate the communication between host 1702 and UE 1706 via network node 1704, without explicit reference to any intermediary devices and the precise routing of messages via these devices.

As an example of transmitting data via OTT connection 1750, in step 1708, host 1702 provides user data, which may be performed by executing a host application. In some embodiments, the user data is associated with a particular human user interacting with UE 1706. In other embodiments, the user data is associated with a UE 1706 that shares data with host 1702 without explicit human interaction. In step 1710, host 1702 initiates a transmission carrying the user data towards UE 1706. Host 1702 may initiate the transmission responsive to a request transmitted by UE 1706. The request may be caused by human interaction with UE 1706 or by operation of the client application executing on UE 1706. The transmission may pass via network node 1704, in accordance with the teachings of the embodiments described throughout this disclosure. Accordingly, in step 1712, network node 1704 transmits to UE 1706 the user data that was carried in the transmission that host 1702 initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1714, UE 1706 receives the user data carried in the transmission, which may be performed by a client application executed on UE 1706 associated with the host application executed by host 1702.

In some examples, UE 1706 executes a client application which provides user data to host 1702. The user data may be provided in reaction or response to the data received from host 1702. Accordingly, in step 1716, UE 1706 may provide user data, which may be performed by executing the client application. In providing the user data, the client application may further consider user input received from the user via an input/output interface of UE 1706. Regardless of the specific manner in which the user data was provided, UE 1706 initiates, in step 1718, transmission of the user data towards host 1702 via network node 1704. In step 1720, in accordance with the teachings of the embodiments described throughout this disclosure, network node 1704 receives user data from UE 1706 and initiates transmission of the received user data towards host 1702. In step 1722, host 1702 receives the user data carried in the transmission initiated by UE 1706.

One or more of the various embodiments improve the performance of OTT services provided to UE 1706 using OTT connection 1750, in which wireless connection 1770 forms the last segment. More precisely, receiving a UE failure report that includes RLM/BFD relaxation information enables a RAN node (or an 0AM system) to determine whether BFD relaxation and/or RLM relaxation degraded the UE’s ability to detect the radio-related failure that triggered the failure report. Based on this determination, the RAN (or 0AM system) can optimize and/or adjust RLM/BFD relaxation parameters used for UEs, which can improve QoS/QoE experienced by users without sacrificing UE energy consumption improvements provided by RLM/BFD relaxation. Accordingly, when used in this manner to improve UEs and RANs that deliver OTT services to end users, embodiments increase the value of such OTT services to both end users and service providers.

In an example scenario, factory status information may be collected and analyzed by host 1702. As another example, host 1702 may process audio and video data which may have been retrieved from a UE for use in creating maps. As another example, host 1702 may collect and analyze real-time data to assist in controlling vehicle congestion (e.g., controlling traffic lights). As another example, host 1702 may store surveillance video uploaded by a UE. As another example, host 1702 may store or control access to media content such as video, audio, VR or AR which it can broadcast, multicast or unicast to UEs. As other examples, host 1702 may be used for energy pricing, remote control of non-time critical electrical load to balance power generation needs, location services, presentation services (such as compiling diagrams etc. from data collected from remote devices), or any other function of collecting, retrieving, storing, analyzing and/or transmitting data.

In some examples, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring OTT connection 1750 between host 1702 and UE 1706, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection may be implemented in software and hardware of host 1702 and/or UE 1706. In some embodiments, sensors (not shown) may be deployed in or in association with other devices through which OTT connection 1750 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software may compute or estimate the monitored quantities. The reconfiguring of OTT connection 1750 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not directly alter the operation of network node 1704. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling that facilitates measurements of throughput, propagation times, latency and the like, by host 1702. The measurements may be implemented in that software causes messages to be transmitted, in particular empty or ‘dummy’ messages, using OTT connection 1750 while monitoring propagation times, errors, etc.

The foregoing merely illustrates the principles of the disclosure. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements, and procedures that, although not explicitly shown or described herein, embody the principles of the disclosure and can be thus within the spirit and scope of the disclosure. Various embodiments can be used together with one another, as well as interchangeably therewith, as should be understood by those having ordinary skill in the art.

The term unit, as used herein, can have conventional meaning in the field of electronics, electrical devices and/or electronic devices and can include, for example, electrical and/or electronic circuitry, devices, modules, processors, memories, logic solid state and/or discrete devices, computer programs or instructions for carrying out respective tasks, procedures, computations, outputs, and/or displaying functions, and so on, as such as those that are described herein.

Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processor (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according to one or more embodiments of the present disclosure.

As described herein, device and/or apparatus can be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of a device or apparatus, instead of being hardware implemented, be implemented as a software module such as a computer program or a computer program product comprising executable software code portions for execution or being run on a processor. Furthermore, functionality of a device or apparatus can be implemented by any combination of hardware and software. A device or apparatus can also be regarded as an assembly of multiple devices and/or apparatuses, whether functionally in cooperation with or independently of each other. Moreover, devices and apparatuses can be implemented in a distributed fashion throughout a system, so long as the functionality of the device or apparatus is preserved. Such and similar principles are considered as known to a skilled person.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

In addition, certain terms used in the present disclosure, including the specification and drawings, can be used synonymously in certain instances (e.g., “data” and “information”). It should be understood, that although these terms (and/or other terms that can be synonymous to one another) can be used synonymously herein, there can be instances when such words can be intended to not be used synonymously.

Embodiments of the techniques and apparatus described herein also include, but are not limited to, the following enumerated examples:

Al . A method for a user equipment (UE) configured for radio link monitoring (RLM) and beam failure detection (BFD) in a radio access network (RAN), the method comprising: performing RLM and BFD in a serving cell provided by a first RAN node; detecting a radio-related failure in the serving cell based on performing RLM and BFD; and sending, to the first RAN node or to a second RAN node, a failure report including RLM/BFD relaxation information pertaining to the RLM and the BFD being performed when the radio-related failure was detected.

A2. The method of embodiment Al, further comprising, before performing RLM and BFD in the serving cell, receiving from the first RAN node an RLM/BFD relaxation configuration that includes the following: one or more first conditions that must be met to perform RLM according to a relaxed RLM measurement configuration, and one or more second conditions that must be met to perform RLM according to a relaxed RLM measurement configuration.

A3. The method of embodiment A2, wherein performing RLM and BFD in the serving cell comprises: determining whether the one or more first conditions are met and whether the one or more second conditions are met; performing RLM in the serving cell according to the relaxed RLM measurement configuration when it is determined that the one or more first conditions are met; performing RLM in the serving cell according to a normal or non-relaxed RLM measurement configuration when it is determined that the one or more first conditions are not met; performing BFD in the serving cell according to the relaxed BFD measurement configuration when it is determined that the one or more second conditions are met; and performing BFD in the serving cell according to a normal or non-relaxed BFD measurement configuration when it is determined that the one or more second conditions are not met.

A4. The method of any of embodiments A2-A3, wherein the RLM/BFD relaxation information in the failure report includes one or more the following: a first indication of whether an RLM relaxation configuration was being used in the serving cell when the failure was detected; at least a portion of the first conditions; a duration that the RLM relaxation configuration had been in use when the radio-related failure was detected; a second indication of whether a BFD relaxation configuration was being used in the serving cell when the failure was detected. at least a portion of the second conditions; and a duration that the RLM relaxation configuration had been in use when the radio-related failure was detected.

A5. The method of any of embodiments A2-A4, wherein: the one or more first conditions include the following: one or more first good serving cell evaluation criteria, and one or more first low mobility evaluation criteria; and the one or more second conditions include the following: one or more second good serving cell evaluation criteria, and one or more second low mobility evaluation criteria.

A6. The method of embodiment A5, wherein the RLM/BFD relaxation information in the failure report includes the following: a first indication of whether an RLM relaxation configuration was being used in the serving cell when the failure was detected; and when the first indication indicates that the RLM relaxation configuration was being used, a further indication of whether the use is based on meeting the first good serving cell criteria or based on meeting the first low mobility evaluation criteria.

A7. The method of any of embodiments A5-A6, wherein the RLM/BFD relaxation information in the failure report includes the following: a second indication of whether a BFD relaxation configuration was being used in the serving cell when the failure was detected; and when the second indication indicates that the BFD relaxation configuration was being used, a further indication of whether the use is based on meeting the second good serving cell criteria or based on meeting the second low mobility evaluation criteria.

A8. The method of any of embodiments A2-A7, wherein: the UE is configured first and second cell groups, with the serving cell being in the first cell group; and the RLM/BFD relaxation configuration includes a first RLM relaxation configuration for the first cell group, a first BFD relaxation configuration for the first cell group, a second RLM relaxation configuration for the second cell group, and a second BFD relaxation configuration for the second cell group.

A9. The method of embodiment A8, wherein the RLM/BFD relaxation information in the failure report includes one of the following: both first RLM/BFD relaxation information for the first cell group and second RLM/BFD relaxation information for the second cell group; or only the first RLM/BFD relaxation information for the first cell group, in which the radiorelated failure was detected.

A10. The method of embodiment A9, wherein the second RLM/BFD relaxation information includes one or more of the following: an indication of whether the second RLM relaxation configuration was being used in the second cell group when the radio-related failure was detected in the serving cell of the first cell group; at least a portion of the second RLM relaxation configuration; a duration that the second RLM relaxation configuration had been in use in the second cell group when the radio-related failure was detected in the serving cell of the first cell group; an indication of one or more conditions that triggered use of the second RLM relaxation configuration in the second cell group; an indication of whether the second BFD relaxation configuration was being used in the second cell group when the radio-related failure was detected in the serving cell of the first cell group; at least a portion of the second BFD relaxation configuration; a duration that the second BFD relaxation configuration had been in use in the second cell group when the radio-related failure was detected in the serving cell of the first cell group; and an indication of one or more conditions that triggered use of the second BFD relaxation configuration in the second cell group.

Al l. The method of any of embodiments A2-A10, further comprising receiving, from the first RAN node or a second RAN node, an updated RLM/BFD relaxation configuration after sending the failure report.

A12. The method of any of embodiments Al-Al l, wherein the radio-related failure is one of the following: a radio link failure (RLF), a handover failure (HOF), a master cell group (MCG) failure, or a secondary cell group (SCG) failure.

A13. The method of any of embodiments A1-A12, wherein the failure report is one of the following messages: RLFReport, MCGFailur eInformation, or SCGFailur eInformation.

Bl. A method for a radio access network (RAN) node configured to support radio link monitoring (RLM) and beam failure detection (BFD) by user equipment (UEs), the method comprising: receiving, from a UE, a failure report about a radio-related failure detected by the UE in a serving cell provided by the RAN node, wherein the failure report includes RLM/BFD relaxation information pertaining to RLM and BFD being performed by the UE when the radio-related failure was detected; and based on the failure report, adjusting one or more parameters of an RLM/BFD relaxation configuration being used in the serving cell.

B2. The method of embodiment Bl, further comprising before receiving the failure report, sending to the UE an RLM/BFD relaxation configuration that includes the following: one or more first conditions that must be met to perform RLM according to a relaxed RLM measurement configuration, and one or more second conditions that must be met to perform RLM according to a relaxed RLM measurement configuration.

B3. The method of embodiment B2, wherein the one or more parameters adjusted based on the failure report include the one or more first conditions and/or the one or more second conditions.

B4. The method of any of embodiments B2-B3, wherein the RLM/BFD relaxation information in the failure report includes one or more the following: a first indication of whether an RLM relaxation configuration was being used in the serving cell when the failure was detected; at least a portion of the first conditions; a duration that the RLM relaxation configuration had been in use when the radio-related failure was detected; a second indication of whether a BFD relaxation configuration was being used in the serving cell when the failure was detected. at least a portion of the second conditions; and a duration that the RLM relaxation configuration had been in use when the radio-related failure was detected.

B5. The method of any of embodiments B2-B4, wherein: the one or more first conditions include the following: one or more first good serving cell evaluation criteria, and one or more first low mobility evaluation criteria; and the one or more second conditions include the following: one or more second good serving cell evaluation criteria, and one or more second low mobility evaluation criteria.

B6. The method of embodiment B5, wherein the RLM/BFD relaxation information in the failure report includes the following: a first indication of whether an RLM relaxation configuration was being used in the serving cell when the failure was detected; and when the first indication indicates that the RLM relaxation configuration was being used, a further indication of whether the use is based on meeting the first good serving cell criteria or based on meeting the first low mobility evaluation criteria.

B7. The method of any of embodiments B5-B6, wherein the RLM/BFD relaxation information in the failure report includes the following: a second indication of whether a BFD relaxation configuration was being used in the serving cell when the failure was detected; and when the second indication indicates that the BFD relaxation configuration was being used, a further indication of whether the use is based on meeting the second good serving cell criteria or based on meeting the second low mobility evaluation criteria.

B8. The method of any of embodiments B2-B7, wherein: the UE is configured first and second cell groups, with the serving cell being in the first cell group; and the RLM/BFD relaxation configuration includes a first RLM relaxation configuration for the first cell group, a first BFD relaxation configuration for the first cell group, a second RLM relaxation configuration for the second cell group, and a second BFD relaxation configuration for the second cell group.

B9. The method of embodiment B8, wherein the RLM/BFD relaxation information in the failure report includes one of the following: both first RLM/BFD relaxation information for the first cell group and second RLM/BFD relaxation information for the second cell group; or only the first RLM/BFD relaxation information for the first cell group, in which the radiorelated failure was detected.

BIO. The method of embodiment B9, wherein when the second RLM/BFD relaxation information includes one or more of the following: an indication of whether the second RLM relaxation configuration was being used in the second cell group when the radio-related failure was detected in the serving cell of the first cell group; at least a portion of the second RLM relaxation configuration; a duration that the second RLM relaxation configuration had been in use in the second cell group when the radio-related failure was detected in the serving cell of the first cell group; an indication of one or more conditions that triggered use of the second RLM relaxation configuration in the second cell group; an indication of whether the second BFD relaxation configuration was being used in the second cell group when the radio-related failure was detected in the serving cell of the first cell group; at least a portion of the second BFD relaxation configuration; a duration that the second BFD relaxation configuration had been in use in the second cell group when the radio-related failure was detected in the serving cell of the first cell group; and an indication of one or more conditions that triggered use of the second BFD relaxation configuration in the second cell group.

Bl 1. The method of any of embodiments Bl -BIO, further comprising sending to the UE an updated RLM/BFD relaxation configuration that includes the adjusted one or more parameters.

B12. The method of any of embodiments Bl-Bl 1, wherein the radio-related failure is one of the following: a radio link failure (RLF), a handover failure (HOF), a master cell group (MCG) failure, or a secondary cell group (SCG) failure.

B13. The method of any of embodiments B1-B12, wherein the failure report is one of the following messages: RLFReport, MCGFailur eInformation, or SCGFailur eInformation.

B14. The method of any of embodiments B1-B13, wherein: receiving the failure report and adjusting the one or more parameters is performed by a central unit (CU) of the RAN node; and the method further comprises the CU sending, to a distributed unit (DU) of the RAN node, an updated RLM/BFD relaxation configuration that includes the adjusted one or more parameters.

B15. The method of any of embodiments B1-B13, wherein: receiving the failure report is performed by a central unit (CU) of the RAN node; the method further comprises forwarding the failure report to a distributed unit (DU) of the RAN node; and adjusting the one or more parameters is performed by the DU of the RAN node.

Cl . A user equipment (UE) configured for radio link monitoring (RLM) and beam failure detection (BFD) in a radio access network (RAN), the UE comprising: communication interface circuitry configured to communicate with at least one RAN node; and processing circuitry operatively coupled to the communication interface circuitry, whereby the processing circuitry and the communication interface circuitry are configured to perform operations corresponding to the methods of any of embodiments Al -Al 3.

C2. A user equipment (UE) configured for radio link monitoring (RLM) and beam failure detection (BFD) in a radio access network (RAN), the UE being further arranged to perform operations corresponding to the methods of any of embodiments Al -Al 3.

C3. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a user equipment (UE) configured for radio link monitoring (RLM) and beam failure detection (BFD) in a radio access network (RAN), configure the UE to perform operations corresponding to the methods of any of embodiments A1-A13.

C4. A computer program product comprising computer-executable instructions that, when executed by processing circuitry of a user equipment (UE) configured for radio link monitoring (RLM) and beam failure detection (BFD) in a radio access network (RAN), configure the UE to perform operations corresponding to the methods of any of embodiments Al -Al 3.

DI . A radio access network (RAN) node configured to support radio link monitoring (RLM) and beam failure detection (BFD) by user equipment (UEs), the RAN node comprising: communication interface circuitry configured to communicate with UEs; and processing circuitry operatively coupled to the communication interface circuitry, whereby the processing circuitry and the communication interface circuitry are configured to perform operations corresponding to the methods of any of embodiments B 1 -B 15.

D2. A radio access network (RAN) node configured to support radio link monitoring (RLM) and beam failure detection (BFD) by user equipment (UEs), the RAN node being further arranged to perform operations corresponding to the methods of any of embodiments B1-B15.

D3. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a radio access network (RAN) node configured to support radio link monitoring (RLM) and beam failure detection (BFD) by user equipment (UEs), configure the RAN node to perform operations corresponding to the methods of any of embodiments B 1 -B 15. D4. A computer program product comprising computer-executable instructions that, when executed by processing circuitry of a radio access network (RAN) node configured to support radio link monitoring (RLM) and beam failure detection (BFD) by user equipment (UEs), configure the RAN node to perform operations corresponding to the methods of any of embodiments B 1 -B 15.