Triggering beam fault recovery during secondary cell group activation

Abstract

A method is disclosed that includes triggering a beam failure recovery procedure for at least one cell of the secondary cell group in response to activating the secondary cell group if one or more predefined conditions are met.

Description

Technical Field

[0001] The following exemplary embodiments relate to wireless communication.

Background Art

[0002] Since resources are limited, it is desirable to optimize the use of network resources. Cells within a cellular communication network can be utilized so that better services can be provided to one or more terminal devices. Therefore, by optimizing the use of one or more cells, better use of resources becomes possible, and the user experience for users of terminal devices can be improved.

Summary of the Invention

[0003] The scope of protection sought for various exemplary embodiments is defined by the independent claims. Exemplary embodiments and features described herein that do not fall within the scope of the independent claims, if any, should be construed as examples useful for understanding the various exemplary embodiments.

[0004] According to one aspect, there is provided an apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to cause the apparatus, using the at least one processor, to execute, in response to activating a secondary cell group when one or more predefined conditions are satisfied, to trigger a beam failure recovery procedure for at least one cell of the secondary cell group.

[0005] According to another aspect, there is provided an apparatus comprising means for triggering a beam failure recovery procedure for at least one cell of a secondary cell group in response to activating the secondary cell group when one or more predefined conditions are satisfied.

[0006] In another embodiment, a method is provided which, in response to activating a secondary cell group, triggers a beam fault recovery procedure for at least one cell in a secondary cell group if one or more predefined conditions are met.

[0007] In another embodiment, a computer program is provided which includes instructions that cause the device to activate the secondary cell group in response to the activation of the secondary cell group, if at least one or more predefined conditions are met, by triggering a beam fault recovery procedure for at least one cell in the secondary cell group.

[0008] In another embodiment, a computer program product is provided which includes program instructions, when executed on a computing device, causes the computing device to activate a secondary cell group in response to the activation of the secondary cell group, if at least one or more predefined conditions are met, by triggering a beam fault recovery procedure for at least one cell of the secondary cell group.

[0009] In another embodiment, a computer-readable medium is provided which includes program instructions, causing the device to activate the secondary cell group in response to the activation of the secondary cell group, if at least one or more predefined conditions are met, by triggering a beam fault recovery procedure for at least one cell in the secondary cell group.

[0010] In another embodiment, a non-temporary computer-readable medium is provided which includes program instructions, causing the device to activate the secondary cell group in response to the activation of the secondary cell group, if at least one or more predefined conditions are met, by triggering a beam fault recovery procedure for at least one cell in the secondary cell group.

[0011] In another embodiment, an apparatus is provided comprising at least one processor and at least one memory containing computer program code, wherein the at least one memory and the computer program code are configured to use at least one processor to cause the apparatus to send a message to a terminal device indicating a configuration for beam fault recovery associated with a secondary cell group, the configuration indicating that, if one or more predefined conditions are met, the secondary cell group will be activated and a beam fault recovery procedure will be triggered for at least one cell of the secondary cell group.

[0012] In another embodiment, an apparatus is provided comprising means for sending a message to a terminal device indicating a configuration for beam fault recovery associated with a secondary cell group, the configuration indicating that, if one or more predefined conditions are met, a beam fault recovery procedure is triggered for at least one cell of the secondary cell group in response to activating the secondary cell group.

[0013] In another embodiment, a method is provided which includes sending a message to a terminal device indicating a configuration for beam fault recovery associated with a secondary cell group, the configuration indicating that, if one or more predefined conditions are met, a beam fault recovery procedure is triggered for at least one cell of the secondary cell group in response to activating the secondary cell group.

[0014] In another embodiment, a computer program is provided which includes instructions causing the device to send a message to a terminal device indicating a configuration for beam fault recovery associated with a secondary cell group, the configuration indicating that, if one or more predefined conditions are met, the secondary cell group will be activated, triggering a beam fault recovery procedure for at least one cell of the secondary cell group.

[0015] In another embodiment, a computer program product is provided which, when executed on a computing device, causes the computing device to send a message to a terminal device indicating a configuration for beam fault recovery associated with a secondary cell group, the configuration indicating that, if one or more predefined conditions are met, the secondary cell group will be activated, triggering a beam fault recovery procedure for at least one cell of the secondary cell group.

[0016] In another embodiment, a computer-readable medium is provided which includes program instructions, causing the device to send a message to a terminal device indicating a configuration for beam fault recovery associated with a secondary cell group, the configuration indicating that, if one or more predefined conditions are met, the secondary cell group will be activated, triggering a beam fault recovery procedure for at least one cell of the secondary cell group.

[0017] In another embodiment, a non-temporary computer-readable medium is provided which includes program instructions, causing the device to send a message to a terminal device indicating a configuration for beam fault recovery associated with a secondary cell group, the configuration indicating that, if one or more predefined conditions are met, the secondary cell group will be activated, triggering a beam fault recovery procedure for at least one cell of the secondary cell group.

[0018] In another embodiment, a system is provided comprising at least a terminal device and a network element of a wireless communication network. The network element is configured to send a message to the terminal device indicating a configuration for beam fault recovery associated with a secondary cell group, the configuration indicating that, if one or more predefined conditions are met, a beam fault recovery procedure is triggered for at least one cell of the secondary cell group in response to activating the secondary cell group. The terminal device is configured to receive a message indicating the configuration from the network element and, if one or more predefined conditions are met, trigger a beam fault recovery procedure for at least one cell of the secondary cell group in response to activating the secondary cell group.

[0019] In another embodiment, a system is provided comprising at least a terminal device and a network element of a wireless communication network. The network element includes means for sending a message to the terminal device indicating a configuration for beam fault recovery associated with a secondary cell group, the configuration indicating that, if one or more predefined conditions are met, a beam fault recovery procedure is triggered for at least one cell of the secondary cell group in response to activating the secondary cell group. The terminal device includes means for receiving a message indicating the configuration from the network element, and means for triggering a beam fault recovery procedure for at least one cell of the secondary cell group in response to activating the secondary cell group, if one or more predefined conditions are met.

[0020] Various exemplary embodiments will be described in more detail below with reference to the attached drawings. [Brief explanation of the drawing]

[0021] [Figure 1] This figure shows an exemplary embodiment of a cellular communication network. [Figure 2] This figure shows an example of a wireless communication system to which several exemplary embodiments may be applied. [Figure 3] This is a signaling diagram showing several exemplary embodiments. [Figure 4] This is a signaling diagram showing several exemplary embodiments. [Figure 5] This is a flowchart illustrating several exemplary embodiments. [Figure 6] This is a flowchart illustrating several exemplary embodiments. [Figure 7] This is a flowchart illustrating several exemplary embodiments. [Figure 8]A flowchart according to some exemplary embodiments. [Figure 9] A flowchart according to some exemplary embodiments. [Figure 10] A flowchart according to some exemplary embodiments. [Figure 11] A flowchart according to some exemplary embodiments. [Figure 12] A diagram showing an apparatus according to some exemplary embodiments. [Figure 13] A diagram showing an apparatus according to some exemplary embodiments

Mode for Carrying Out the Invention

[0022] The following embodiments are exemplary. This specification may refer to "an", "one", or "some" embodiments (plural possible) at several places in the text, but this does not necessarily mean that each reference refers to the same embodiment (plural possible), or that a particular feature applies only to a single embodiment. It is also possible to combine the single features of different embodiments to provide other embodiments.

[0023] In the following, different exemplary embodiments are described using radio access architectures based on Long-Term Evolution Advanced (LTE Advanced, LTE-A) or New Radio (NR, 5G) as examples of access architectures to which exemplary embodiments may be applied, but the exemplary embodiments are not limited to such architectures. It will also be apparent to those skilled in the art that exemplary embodiments may be applied to other types of communication networks having suitable means by suitably adjusting the parameters and procedures. Some examples of other options for a suitable system include Universal Mobile Communications System (UMTS) Radio Access Network (UTRAN or E-UTRAN), Long-Term Evolution (LTE, substantially the same as E-UTRAN), Wireless Local Area Network (WLAN or Wi-Fi), Worldwide Interoperability for Microwave Access (WiMAX), Bluetooth®, Personal Communication Services (PCS), ZigBee®, Wideband Code Division Multi-Access (WCDMA), systems using ultra-wideband (UWB) technology, sensor networks, mobile ad hoc networks (MANET), and Internet Protocol Multimedia Subsystem (IMS), or any combination thereof.

[0024] Figure 1 shows a simplified example of a system architecture, illustrating several elements and functional entities. These elements and functional entities are all logical units, and their embodiments may differ from those illustrated. The connections shown in Figure 1 are logical connections; actual physical connections may differ. It will be apparent to those skilled in the art that the system may also have functions and structures other than those shown in Figure 1.

[0025] However, the exemplary embodiments are not limited to the systems given as examples, and those skilled in the art can apply this solution to other communication systems provided with the necessary characteristics.

[0026] The example in Figure 1 shows a portion of an exemplary wireless access network.

[0027] Figure 1 shows user devices 100 and 102 configured to wirelessly connect to an access node (e.g., NodeB) 104 providing the cell over one or more communication channels within the cell. The physical links from the user devices to NodeB may be called uplinks or reverse links, and the physical links from NodeB to the user devices may be called downlinks or forward links. It should be understood that NodeB or its functionality may be implemented using any entity such as a node, host, server, or access point suitable for such use.

[0028] The communication system may comprise two or more (e.g.) NodeBs, in which case (e.g.) NodeBs may also be configured to communicate with each other via wired or wireless links designed for that purpose. These links may be used for signaling purposes. (e.g.) A NodeB may be a computing device configured to control the wireless resources of the communication system to which it is coupled. (e.g.) A NodeB may also be called a base station, access point, or any other type of interface device, including a relay station capable of operating in a wireless environment. (e.g.) A NodeB may include or be coupled to a transceiver. (e.g.) A connection may be provided from the transceiver of a NodeB to an antenna unit that establishes a bidirectional wireless link to a user device. The antenna unit may comprise multiple antennas or antenna elements. (e.g.) A NodeB may further be connected to a core network 110 (CN or next-generation core NGC). Depending on the system, the counterpart on the CN side may be a serving gateway (S-GW, which routes and forwards user data packets), a packet data network gateway (P-GW) that provides connectivity for user devices (UEs) to the external packet data network, or a mobile management entity (MME).

[0029] A user device (also called a UE, user equipment, user terminal, terminal device, etc.) represents one type of device to which resources of an air interface can be allocated and assigned, and therefore any feature described herein with respect to a user device can be implemented by a corresponding device such as a relay node. An example of such a relay node may be a Layer 3 relay to a base station (self-backhaul relay). A self-backhaul relay node may also be called an integrated access and backhaul (IAB) node. An IAB node may have two logical parts: a mobile termination (MT) portion that deals with backhaul links (multiple) (i.e., links (multiple) between the IAB node and donor nodes, also known as parent nodes) and a distributed unit (DU) portion that deals with access links (multiple), i.e., child links (multiple) between the IAB node and UE(multiple) and / or between the IAB node and other IAB nodes (multi-hop scenarios).

[0030] A user device can refer to a portable computing device, including a wireless mobile communication device that operates with or without a subscriber identification module (SIM), and this includes, but is not limited to, the following types of devices: mobile stations (cell phones), smartphones, personal digital assistants (PDAs), handsets, devices using wireless modems (such as alarm or measuring devices), laptops and / or touchscreen computers, tablets, game consoles, notebooks, and multimedia devices. It should also be understood that a user device may be a device that is almost exclusively uplink-based, one example being a camera or camcorder that loads images or video clips onto a network. A user device may also be a device with capabilities that operate on an Internet of Things (IoT) network, a scenario in which an object may be provided with the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction. User devices may also utilize the cloud. In some applications, a user device may comprise a small portable device with wireless components (e.g., a watch, earphones, or glasses), with computing performed in the cloud. A user device (or, in some exemplary embodiments, a Layer 3 relay node) may be configured to perform one or more of the user device functions. User devices may also be called subscriber units, mobile stations, remote terminals, access terminals, user terminals, terminal devices, or user equipment (UE), to name just a few examples of the types of devices that can be used.

[0031] The various technologies described herein can also be applied to cyber-physical systems (CPS) (systems that coordinate computational elements to control physical entities). CPS can enable the implementation and utilization of a large number of interconnected ICT devices (sensors, actuators, processors, microcontrollers, etc.) embedded in physical objects in various locations. Mobile cyber-physical systems, in which the physical system in question may have inherent mobility, are a subcategory of cyber-physical systems. Examples of mobile-physical systems include mobile robots and electronic devices carried by humans or animals.

[0032] Furthermore, although these devices are shown as a single entity, various units, processors, and / or memory units (not all of which are shown in Figure 1) may be implemented.

[0033] 5G will enable even more base stations or nodes than LTE (the so-called small cell concept) by using multi-input multi-output (MIMO) antennas, including macrosites that work in conjunction with smaller stations and employ various radio technologies depending on service needs, use cases, and / or available spectrum. 5G mobile communications can support a wide range of use cases and related applications, such as video streaming, augmented reality, various data sharing methods, and various forms of machine-type applications, such as (large-scale) machine-type communications (mMTC), such as vehicle safety, various sensors, and real-time control. 5G is expected to have multiple radio interfaces, such as sub-6GHz, cm wave, and mm wave, and can be integrated with existing legacy radio access technologies such as LTE. Integration with LTE can be implemented, at least in its initial stages, as a system where macro coverage can be provided by LTE, and 5G radio interface access can be obtained from small cells through aggregation to LTE. In other words, 5G can support both RAT-to-RAT operability (e.g., LTE-5G) and RI-to-RI operability (radio interface-to-radio interface operability, e.g., sub-6GHz-cm wave, sub-6GHz-cm wave-mm wave). One concept that is likely to be used in 5G networks may be network slicing, where multiple independent, dedicated virtual subnetworks (network instances) can be created within substantially the same infrastructure to run services with different requirements regarding latency, reliability, throughput, and mobility.

[0034] The current architecture of LTE networks can be fully distributed wirelessly and fully centralized in the core network. Low-latency applications and services of 5G may need to bring content closer to wireless, which leads to local breakout and multi-access edge computing (MEC). 5G may enable analysis and knowledge generation that occurs at the data source. This approach may need to leverage resources that may not be continuously connected to the network, such as laptops, smartphones, tablets, and sensors. MEC can provide a distributed computing environment for hosting applications and services. It may also have the ability to store and process content near the cellular subscriber to reduce response times. Edge computing can cover a wide range of technologies, such as wireless sensor networks, mobile data acquisition, mobile signature analysis, collaborative distributed peer-to-peer ad-hoc networking and processing (which can also be classified as local cloud / due computing and grid / mesh computing), fog computing, mobile edge computing, cloudlets, distributed data storage and acquisition, autonomous self-healing networks, remote cloud services, augmented and virtual reality, data caching, the Internet of Things (large-scale connectivity and / or latency-critical), and critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, healthcare applications).

[0035] A communication system may also be able to communicate with other networks, such as the public switched telephone network or the Internet 112, and utilize services provided by them. A communication network may also be able to support the use of cloud services, for example, at least part of the core network operation may be run as a cloud service (indicated by “cloud” 114 in Figure 1). A communication system may also include a central control entity that provides facilities for different operators’ networks to cooperate, for example, in spectrum sharing.

[0036] By utilizing network function virtualization (NFV) and software-defined networking (SDN), edge clouds can be integrated into radio access networks (RANs). The use of edge clouds may mean that access node operations are performed at least partially in base stations equipped with servers, hosts, or nodes, or radio components, that are operablely coupled to remote radio heads (RRHs) or radio units (RUs). Node operations may also be distributed across multiple servers, nodes, or hosts. Performing RAN real-time functions on the RAN side (in the distributed unit DU104) and non-real-time functions in a centralized manner (in the central unit CU108) can be achieved, for example, by applying a cloud RAN architecture.

[0037] Furthermore, it should be understood that the workload distribution between core network operations and base station operations may differ from, or even be nonexistent, in the case of LTE. Other possible technological advancements include big data and all-IP, which could change how networks are built and managed. 5G (or New Radio NR) networks may be designed to support multiple layers, with MEC servers placed between the core and base stations or nodeBs (gNBs). It should be understood that MEC can also be applied to 4G networks.

[0038] Furthermore, 5G can enhance or complement the coverage of 5G services by utilizing satellite communications, for example, by providing backhaul. Possible use cases include providing service continuity to machine-to-machine (M2M) or Internet of Things (IoT) devices, or to passengers in vehicles, or ensuring service availability for critical communications and future rail / maritime / air communications. Satellite communications can utilize geostationary earth orbit (GEO) satellite systems, but can also utilize low earth orbit (LEO) satellite systems, particularly megaconstellations (systems with hundreds of (nano) satellites). At least one satellite 106 within a megaconstellation may cover several satellite-enabled network entities that create ground cells. Ground cells can be created via ground relay nodes 104, or by gNBs located on the ground or within satellites.

[0039] The illustrated system is only one example of a wireless access system, and it will be apparent to those skilled in the art that in reality, a system may comprise multiple (e.g.) NodeBs, user devices may be able to access multiple wireless cells, and the system may also comprise other devices such as physical layer relay nodes or other network elements. At least one of the (e.g.) NodeBs may be a home (e.g.) NodeB.

[0040] Furthermore, (e / g) a nodeB or base station may also be divided into a radio unit (RU) comprising a radio transceiver (TRX), i.e., a transmitter (TX) and a receiver (RX); one or more distributed units (DUs) that can be used for so-called Layer 1 (L1) processing and real-time Layer 2 (L2) processing; and a central unit (CU) or centralized unit that can be used for non-real-time L2 and Layer 3 (L3) processing. The CU may be connected to one or more DUs, for example, using an F1 interface. Such a division may allow for the centralization of CUs relative to cell sites and DUs, while DUs may be more distributed or even remain at cell sites. The CU and DU together may also be called a baseband or baseband unit (BBU). The CU and DU may also both be included in a radio access point (RAP).

[0041] A CU may be defined as a logical node that hosts higher-layer protocols, such as radio resource control (RRC), service data adaptation protocol (SDAP), and / or packet data convergence protocol (PDCP), for (e.g.) nodeB or base station. A DU may be defined as a logical node that hosts the radio link control (RLC) layer, media access control (MAC) layer, and / or physical (PHY) layer, for (e.g.) nodeB or base station. The operation of the DU may be controlled at least partially by the CU. A CU may comprise a control plane (CU-CP), which may be defined as a logical node that hosts the RRC and the control plane portion of the CU's PDCP protocol, for (e.g.) nodeB or base station. A CU may further comprise a user plane (CU-UP), which may be defined as a logical node that hosts the user plane portions of the CU's PDCP and SDAP protocols, for (e.g.) nodeB or base station.

[0042] Cloud computing platforms may also be used to operate CUs and / or DUs. A CU may operate on a cloud computing platform, which may be called a virtualized CU (vCU). In addition to vCUs, virtualized DUs (vDUs) that operate on cloud computing platforms may also exist. Furthermore, there may be combinations in which the DU uses so-called bare-metal solutions, such as application-specific integrated circuits (ASICs) or customer-specific standard product (CSSP) system-on-chip (SoC) solutions. It should also be understood that the distribution of work between the aforementioned base station units, or between different core network operations and base station operations, may differ.

[0043] Furthermore, the geographical area of ​​a wireless communication system may be provided with multiple different types of radio cells, as well as multiple radio cells. Radio cells can be macrocells (or umbrella cells), which are large cells with diameters up to tens of kilometers, or smaller cells such as microcells, femtocells, or picocells. (e.g.) NodeB in Figure 1 can provide any type of these cells. A cellular wireless system can be implemented as a multilayer network containing several types of cells. In a multilayer network, one access node may provide one or more cells of one type, so multiple (e.g.) NodeBs may be required to provide such a network structure.

[0044] To meet the needs for deploying and improving the performance of communication systems, the "plug-and-play" (e.g.) NodeB concept may be introduced. Networks that may use "plug-and-play" (e.g.) NodeB may include a home (e.g.) NodeB (H(e.g.)nodeB), as well as a home nodeB gateway or HNB-GW (not shown in Figure 1). An HNB gateway (HNB-GW), which may be installed within the operator's network, can aggregate traffic from multiple HNBs and return it to the core network.

[0045] Figure 2 shows an example of a wireless communication system 200 to which several exemplary embodiments may be applied. At least a portion of the wireless communication system 200 may be configured to implement carrier aggregation with dual connectivity (DC). Dual connectivity allows the UE 203 to connect to two cell groups simultaneously: a master cell group (MCG) 210 and a secondary cell group (SCG) 220. Dual connectivity may be combined with carrier aggregation, and multiple cells (e.g., one for each aggregated carrier) may exist within a given cell group. The two cell groups may be associated with different RAN nodes 201, 202 (i.e., base stations). The two cell groups may be based on different radio access technologies (e.g., LTE and 5G) or on the same radio access technology.

[0046] MCG210 is a group of serving cells associated with the master node 201 (i.e., the RAN node that provides control plane connectivity to the core network). MCG210 includes a primary cell (PCell) 211, i.e., a special cell (SpCell) of MCG210, and optionally one or more secondary cells (SCell) 212. PCell 211 is a cell that operates on a primary frequency which may be used for initial access under MCG210. SCells are cells that operate on secondary frequencies which may be configured once RRC connectivity is established and may be used to provide additional radio resources. A given serving cell may be associated with physical resources which may be from one or more actual transmission and reception points (TRPs), and UE203 may also be configured to utilize one or more TRPs. In such cases, UE203 may use resources from two or more cells per aggregated carrier or frequency.

[0047] SCG220 is a group of serving cells associated with secondary node 202 (i.e., a RAN node that provides additional resources to the UE). SCG220 comprises primary secondary cell (PSCell) 221, i.e., the SpCell of SCG, and optionally one or more SCells 222. PSCell 221 is a cell that may be used for initial access under SCG220.

[0048] An SCG may be deactivated based on factors such as the expected data rate of the UE on the uplink and / or downlink, and / or the SCG activation latency, and / or the UE's power consumption, and / or the radio bearers that have data to be transmitted by the UE or base station. In an SCG deactivated state, the PSCell and all SCells of the SCG may be deactivated. For example, if the UE's expected data rate is low (e.g., below a threshold), but the network wants to be able to use the SCG immediately when the data rate increases, the SCG may be deactivated because no additional radio resources of the SCG are needed at the moment. As another example, if the UE's expected data rate is concentrated on the signaling / data radio bearers associated with the MCG (e.g., there is no data, or only a small amount of data, on the radio bearers associated with the SCG), the SCG may be deactivated because no additional radio resources of the SCG are needed at the moment. Deactivating an SCG may mean deactivating data transmission between the UE and the SCG. The UE may remain in RRC connection mode with the SCG when the SCG is inactive. In the SCG inactive state, the PSCell may continue to perform measurement monitoring and / or beam tracking at cycles that may differ compared to the activated state, for example, but physical uplink control / shared channel (PUCCH / PUSCH) transmission and physical downlink control / shared channel (PDCCH / PDSCH) reception with the UE may be disabled. When the SCG is activated, at least the PSCell is activated (i.e., data transmission between the UE and the PSCell is enabled), but the SCell of the SCG may remain inactive. Alternatively, some or all of the SCell of the SCG may be activated.Activation and / or deactivation of the SCG may be performed via explicit activation / deactivation commands from the network, or implicitly, autonomously by the UE based on one or more internal triggers such as a timer or a data rate threshold, or by data occurrence on one or more radio bearers associated with the SCG.

[0049] Beamforming is a signal processing technology used in 5G communications and other applications. It allows base stations to transmit targeted, directional radio signals (beams) to the UE (Union Engine), thereby reducing interference, improving spectral efficiency, and enabling more efficient use of the frequency spectrum.

[0050] When an UE is moving or indoors, the radio link between the UE and the base station is susceptible to interference and degradation of the radio signal, which can cause the communication link to suddenly break and beam failures to occur. To detect beam failures in an appropriate time, the UE may perform beam failure detection (BFD) procedures to measure such sudden and rapid changes in the communication link. For example, if the physical layer (i.e., L1) detects that the reference signal received power (RSRP), measured on the serving beam's reference signal, has fallen below a threshold, a beam failure instance (BFI) may be triggered and sent to the MAC layer. As another example, if the physical layer (i.e., L1) detects that the target block error rate (BLER), measured on the serving beam's physical downlink control channel (PDCCH), has exceeded a threshold, a beam failure instance (BFI) may be triggered and sent to the MAC layer. When the MAC layer receives a BFI, it starts a timer (beamFailureDetectionTimer) and continuously increments the BFI counter (BFI_COUNTER) by 1 for each BFI. When a certain threshold for BFIs (beamFailureInstanceMaxCount) is reached, the MAC layer triggers a beam failure and initiates the beam failure recovery (BFR) procedure.

[0051] The Beam Freeze (BFR) procedure allows the UE to recover from a beam failure and continue service. When a beam failure occurs, the UE loses a link from one beam, but during the BFR procedure, it may be possible to establish a link to another beam. BFR for SpCells can be performed via a Random Access (RA) procedure, while BFR for SCells can use MAC control element (MAC CE) based reporting. The UE may identify a new candidate beam, which can then be communicated to the base station via the RA procedure (SpCell) or MAC CE (SCell).

[0052] During an RA procedure, a UE may send a random access preamble to a SpCell via a physical random access channel (PRACH) to obtain uplink synchronization and to indicate a candidate beam. There are at least two types of RA procedures: contention-based random access (CBRA) and contention-free random access (CFRA). CFRA may also be called contention-free random access. In CFRA, the UE has a dedicated random access preamble assigned by the network, whereas in CBRA, the UE randomly selects a preamble from a pool of preambles shared with other UEs in the cell. In CBRA, contention (or collision) can occur if two or more UEs attempt to perform a random access procedure using the same random access procedure on the same resource. In response to the random access preamble received from the UE, the network may send a random access response to the UE. The random access response (RAR or Msg2) may include timing advance (TA) information defined by the network based on the random access preamble (Msg1) received from the UE.

[0053] According to the legacy specification, for a given serving cell configured for BFD, if a BFI indication is received from a lower layer, the MAC entity may start or restart a timer called beamFailureDetectionTimer and increment a beam failure instance (BFI) counter called BFI_COUNTER by 1. In other words, BFI_COUNTER counts the number of BFIs. If BFI_COUNTER is greater than or equal to a threshold called beamFailureInstanceMaxCount, a beam failure may be considered detected, and if the serving cell is a SCell, a BFR may be triggered for this serving cell. If the serving cell is not a SCell, a random access procedure may be initiated for the SpCell.

[0054] The timer beamFailureDetectionTimer and the threshold beamFailureInstanceMaxCount can be defined, for example, as follows: beamFailureInstanceMaxCount ENUMERATED {n1, n2, n3, n4, n5, n6, n8, n10} OPTIONAL, -- Need R beamFailureDetectionTimer ENUMERATED {pbfd1, pbfd2, pbfd3, pbfd4, pbfd5, pbfd6, pbfd8, pbfd10} OPTIONAL, -- Need R

[0055] The beamFailureDetectionTimer is a timer for BFD. The timer value is several Q values ​​of the beam fault detection reference signal. out,LR This is the number of reporting periods. For example, the value pbfd1 is one Q of the beam fault detection reference signal. out,LR Corresponding to the reporting period, the value pbfd2 is the two Q values ​​of the beam fault detection reference signal. out,LR The same applies to the reporting period below.

[0056] The BFI threshold value, beamFailureInstanceMaxCount, defines how many beam failure instances occur before the UE triggers a BFI. For example, value n1 corresponds to one BFI, value n2 to two BFIs, and so on.

[0057] The BFD and BFR procedures can be used, for example, in frequency range 2 (FR2) operation, frequency range 1 (FR1) operation, or any other current or future frequency range. FR1 is 450 MHz to 6 GHz. FR2 is 24.25 GHz to 52.6 GHz.

[0058] NR Rel-17 may provide support for performing BFD while the SCG is deactivated. If the Time Alignment Timer (TAT) is maintained or still operating after SCG deactivation and no beam fault is detected, the random access procedure may not be necessary during SCG activation (i.e., the UE may activate the PSCell without random access in this case). Otherwise, the random access procedure may be performed. The TAT may be used to control the length of time during which the UE is considered to be performing uplink time adjustment. The UE may start or restart the TAT when it receives a timing advance command from the network.

[0059] If BFD is performed while the SCG is deactivated, it may be beneficial to allow the BFR procedure to run to notify the network about the failed beam. However, if there is no data activity requiring SCG activation, it may not be necessary to run BFR immediately upon detecting a beam failure, because this could cause the network to interpret BFR as SCG activation, thereby unnecessarily increasing UE power consumption and network resource consumption.

[0060] Some exemplary embodiments provide a mechanism to prevent a beam failure failure (BFR) from being triggered if BFI_COUNTER is greater than or equal to the BFI threshold (beamFailureInstanceMaxCount) while the SCG is deactivated. A BFR may be triggered by the UE if BFI_COUNTER is greater than or equal to the BFI threshold (beamFailureInstanceMaxCount) when the SCG is activated, or if the beamFailureDetectionTimer is still running when the SCG is activated (for example, if a beam failure was detected while the SCG was deactivated).

[0061] Figure 3 shows a signaling diagram according to an exemplary embodiment, in which the BFR is not triggered during SCG activation if one or more predefined conditions are not met. The signaling shown in Figure 3 may be implemented, for example, in the wireless communication system shown in Figure 2.

[0062] Referring to Figure 3, the UE is configured for dual connectivity with the MCG and SCG (301). The MCG is hosted by the master node, and the SCG is hosted by the secondary node. The master node may also be called the first base station, and the secondary node may also be called the second base station. The UE can transmit data (uplink and / or downlink) to and from the MCG. The UE can also transmit data (uplink and / or downlink) to and from the SCG (i.e., the SCG may be in an active state initially).

[0063] The master node sends an SCG deactivation command to the UE via the MCG (302). Alternatively, a secondary node may send an SCG deactivation command to the UE via the SCG (302). The SCG deactivation command indicates a request from the UE to switch from an SCG activated state to an SCG deactivated state. The decision to deactivate the SCG may be made by the master node or a secondary node and may be based on a comparison of data volume or a comparison of expected traffic rates. For example, the master node or a secondary node may decide to deactivate the SCG if the data volume is below a first threshold and / or the traffic rate is below a second threshold and / or if the network wants to allow low latency for SCG activation. The term “data volume” may refer to the amount of data transferred between or to be transferred between the UE and the SCG. Similarly, the term “traffic rate” may refer to the rate of data traffic transferred between or to be transferred between the UE and the SCG. Similarly, the term "low latency" may refer to the network being aware of the UE functionality that deactivates the SCG. The master node may also send an SCG deactivation request to a secondary node, which may deactivate the UE context in the SCG in response to the received request. An SCG deactivation request may also be called a secondary node (SN) change request.

[0064] In response to receiving the SCG deactivate command 302, the UE enters the SCG deactivate state (303), and data transmission to and from the SCG (on the uplink and downlink) is deactivated. Data transmission to the MCG may continue even in the SCG deactivate state.

[0065] The UE performs a BFD on the serving cell of the SCG while the SCG is in an inactive state (304). The UE does not initiate a BFR even if it determines that BFI_COUNTER is greater than or equal to the BFI threshold (beamFailureInstanceMaxCount) while the SCG is in an inactive state (305). In other words, if BFI_COUNTER reaches the threshold while the SCG is in an inactive state, a BFR is not triggered. If beamFailureDetectionTimer expires before SCG activation, the UE may reset BFI_COUNTER to 0 (306).

[0066] The master node sends an SCG activation command to the UE via the MCG (307) if the master node or secondary node determines that the current data volume is greater than the first threshold, and / or the traffic rate is greater than the second threshold, and / or the network wants to enable better scheduling diversity by allowing UEs to be scheduled from multiple serving cells, and / or the network determines that data is available. Alternatively, the UE may request SCG activation from the master node, and the master node may respond to that request by sending an SCG activation command to the UE. The SCG activation command indicates a request for the UE to switch from an SCG non-activated state to an SCG activated state. Upon receiving the SCG activation command, the UE may switch to an SCG activated state. Alternatively, the UE may initiate SCG activation based on internal triggers within the UE, for example, if it determines that the amount of data exceeds a configured threshold, or if data becomes available on a specific wireless bearer(s).

[0067] When the UE receives an SCG activation command (or enters the SCG activated state), if it determines that the TAT is still running (i.e., the TAT has not expired) and the BFI_COUNTER is below the BFI threshold (beamFailureInstanceMaxCount), 308 the UE sends an SCG activation message to the secondary node without executing the random access procedure to the SCG's PSCell (i.e., without BFR) (309). The SCG activation message indicates a switch to the SCG activated state. For example, a scheduling request may be used as the SCG activation message 309.

[0068] The secondary node may activate the UE context in the SCG in response to receiving an SCG activation message from the UE. The secondary node sends a response to the UE to acknowledge receipt of the UE activation message and, consequently, to acknowledge the switch to the SCG activated state (310). In the SCG activated state, data transmission to and from the SCG becomes possible (i.e., the UE can transfer data to, for example, the SCG's PSCell).

[0069] Figure 4 shows a signaling diagram according to an exemplary embodiment, in which a BFR is triggered upon SCG activation if one or more predefined conditions are met. The signaling shown in Figure 4 may be implemented, for example, in the wireless communication system shown in Figure 2.

[0070] Referring to Figure 4, the UE is configured for dual connectivity with the MCG and SCG (401). The MCG is hosted by the master node, and the SCG is hosted by the secondary node. The master node may also be called the first base station, and the secondary node may also be called the second base station. The UE can transmit data (uplink and / or downlink) to and from the MCG. The UE can also transmit data (uplink and / or downlink) to and from the SCG (i.e., the SCG may be in an active state initially).

[0071] The master node sends an SCG deactivation command (402) to the UE via the MCG. Alternatively, a secondary node may send an SCG deactivation command (402) to the UE. The decision to deactivate the SCG may be made at either the master node or the secondary node. The master node may also send an SCG deactivation request to the secondary node, which may deactivate the UE's context in the SCG in response to the received request.

[0072] In response to receiving the SCG deactivation command 402, the UE enters the SCG deactivation state 403, and data transmission (uplink and downlink) to and from the SCG is deactivated. Data transmission related to the MCG may continue even in the SCG deactivation state.

[0073] The UE performs a BFD on the serving cells of the SCG (e.g., SpCell / PSCell) while the SCG is in an inactive state (404). The UE does not initiate a BFR even if it determines that the BFI_COUNTER is greater than or equal to the BFI threshold (beamFailureInstanceMaxCount) while the SCG is in an inactive state (405). In other words, if the BFI_COUNTER reaches the threshold (i.e., a beam failure is detected) while the SCG is inactive, a BFR is not triggered.

[0074] If a beam fault is detected while the SCG is still in a deactivated state, the UE may trigger, cause to expire, or consider the TAT to expire. In this specification, triggering the TAT to expire may, for example, mean configuring the TAT value to zero. Alternatively, the UE may wait until the SCG is activated before triggering, causing to expire, or considering the TAT to expire. This allows the UE to recover the beam (if possible) while the SCG is deactivated, and if this occurs during TAT operation, the UE can still access the PSCell (i.e., the SCG's SpCell) without executing a random access procedure. However, if the beam is still faulty when the SCG is activated, the TAT expiration forces the UE to execute a random access procedure and perform a BFR on the PSCell. Whether the TAT is triggered to expire when the SCG is inactive, or whether this happens later when the SCG is activated, may be configured by the network, or this may be a pre-configured UE feature.

[0075] The master node sends an SCG activation command (406) to the UE via the MCG. Upon receiving the SCG activation command, the UE may switch to the SCG activated state. In response to receiving the SCG activation command (or when entering the SCG activation state), the UE decides to trigger (407) or perform a BFR procedure for the serving cell (e.g., SpCell) of the SCG if one or more of the following predefined conditions are met: 1) BFI_COUNTER is greater than or equal to the BFI threshold (e.g., beamFailureInstanceMaxCount) for SCG activation; 2) the UE has previously detected a beam fault in step 405 and the beam fault detection timer (e.g., beamFailureDetectionTimer) is still running at the time of SCG activation; 3) the UE triggers a TAT expiration at SCG activation due to a beam fault previously detected in step 405; and / or 4) the TAT has expired at the time of SCG activation (e.g., this may have expired previously in step 405).

[0076] The UE sends an SCG activation message to the secondary node, 408, and executes a random access procedure to the SCG's PSCell (i.e., SCG activation with BFR). For example, CBRA can be used as the random access procedure for BFR. Alternatively, if a CFRA BFR resource, such as a dedicated preamble, is configured in the UE, CFRA can be used as the random access procedure for BFR.

[0077] The secondary node may activate the UE context in the SCG in response to receiving an SCG activation message from the UE. The UE receives a response from the secondary node confirming receipt of the SCG activation message and switching to the SCG activated state (409). In the SCG activated state, data transmission to and from the SCG becomes possible, i.e., the UE can transfer data uplink and downlink to, for example, the SCG's PSCell. Response 409 may include a random access response, which may include timing advance commands applied by the UE for uplink synchronization with the PSCell.

[0078] Figure 5 shows a flowchart according to an exemplary embodiment. The functions shown in Figure 5 may be performed by a device such as a terminal device (e.g., UE203 in Figure 2), or a device included in a terminal device. This device may be configured for dual connection with MCG and SCG. Referring to Figure 5, if one or more predefined conditions are met, a beam fault recovery procedure is triggered (501) or initiated for at least one cell of the SCG in response to activating the SCG. The SCG may be activated in response to receiving an SCG activation command or indication from the network, or by autonomously triggering SCG activation by the UE itself based on an internal trigger. At least one cell may include at least one serving cell of the SCG. In other words, at least one cell may include at least one of the PSCell, SpCell, and / or SCell of the SCG. During the beam fault recovery procedure, the instrument may (if the SpCell / PSCell is a serving cell) send a random access preamble to the SCG's SpCell / PSCell to establish a link to a beam different from the beam in which the beam fault was detected.

[0079] For example, one or more predefined conditions may include at least one of a first predefined condition and / or a second predefined condition.

[0080] The first predefined condition is met when, at the time of activating the SCG, the beam failure instance counter (BFI_counter) associated with at least one cell is greater than or equal to the beam failure instance threshold. The beam failure instance threshold may also be called beamFailureInstanceMaxCount.

[0081] A second predefined condition may be met if, when activating the SCG, a beam failure detection timer associated with at least one cell is operating. The beam failure detection timer may also be called a beamFailureDetectionTimer.

[0082] Alternatively, the second predefined condition may be met if a beam fault is detected in at least one cell while the SCG is deactivated, and the beam fault detection timer is running when the SCG is activated.

[0083] Figure 6 shows a flowchart according to an exemplary embodiment, in which the TAT is triggered to expire when a beam fault is detected while the SCG is in an inactive state. Therefore, since the TAT is considered expired when the SCG is activated, the UE may be forced to perform a random access procedure with the serving cells of the SCG when the SCG is activated. The functionality shown in Figure 6 may be performed by an apparatus such as a terminal device (e.g., UE203 in Figure 2) or an apparatus contained within a terminal device. Referring to Figure 6, a beam fault is detected in at least one cell of the SCG while the SCG is inactive (601). A beam fault may be detected if BFI_counter is greater than or equal to beamFailureInstanceMaxCount. When a beam fault is detected while the SCG is inactive, the time alignment timer (TAT) associated with at least one cell is triggered to expire (602), or is made to expire. In other words, if a beam fault is detected while the SCG is not activated, without waiting for SCG activation, the TAT will expire.

[0084] Figure 7 shows a flowchart according to an exemplary embodiment, in which the UE waits for SCG activation after detecting a beam fault in the SCG deactivated state, before triggering the TAT to expire. Therefore, since the TAT is considered expired at the time of SCG activation, the UE may be forced to perform a random access procedure with the serving cells of the SCG at the time of SCG activation. The function shown in Figure 7 may be performed by an apparatus such as a terminal device (e.g., UE203 in Figure 2), or an apparatus contained within a terminal device. Referring to Figure 7, a beam fault is detected in at least one cell of the SCG while the SCG is deactivated (701). For example, a beam fault may be detected if BFI_counter is greater than or equal to beamFailureInstanceMaxCount. This apparatus waits until the SCG is activated (702). In response to SCG activation, the time alignment timer (TAT) associated with at least one cell is triggered to expire (703), or is made to expire, or is considered expired.

[0085] Figure 8 shows a flowchart of another exemplary embodiment. The functions shown in Figure 8 may be performed by a device such as a terminal device (e.g., UE203 in Figure 2) or a device included in a terminal device. Referring to Figure 8, the UE stops running BFD on at least one cell of the SCG when the TAT expires (801). This is because, since the TAT has expired, a random access procedure must be performed on the SpCell during SCG activation anyway. Stopping the execution of BFD may depend on whether a CFRA BFD resource is configured in the UE. In other words, if a CFRA resource such as a dedicated preamble is not configured, the UE may be allowed to stop running BFD when the TAT expires. If a CFRA resource is configured, the UE may be allowed to continue running BFD even after the TAT expires.

[0086] Figure 9 shows a flowchart of another exemplary embodiment. The functions shown in Figure 9 may be performed by a device such as a terminal device (e.g., UE203 in Figure 2) or a device included in a terminal device. Referring to Figure 9, a beam fault detected in at least one cell of an inactivated SCG is indicated via the MCG or master node (901). In other words, in this exemplary embodiment, when a beam fault is detected in a serving cell (e.g., SpCell) of an inactivated SCG, the UE may trigger a BFR procedure via the master node. For example, the UE may indicate the occurrence of a beam fault and a candidate beam in the serving cell (e.g., SpCell) of the SCG via the master node / MCG. Such indication may utilize RRC signaling or lower-layer signaling (e.g., downlink control information DCI, or MAC CE) directed to the master node / MCG. For example, an RRC message may be tunneled through the master node to a secondary node, which can interpret the UE's RRC message. For example, a secondary node may decide to respond to the UE via the master node / MCG by using RRC signaling. The UE may send an indication when it detects a beam fault in a serving cell of an inactivated SCG (e.g., a SpCell) or when it activates the SCG (i.e., when it receives an SCG activation command or when the UE itself triggers SCG activation).

[0087] Figure 10 shows a flowchart according to an exemplary embodiment, in which the network configures how the UE behaves with respect to BFR and / or TAT expiration. In other words, the network can configure the UE to perform the UE action(s) described above with reference to any of Figures 3 to 9. The functions shown in Figure 10 may be performed by devices such as network elements, such as base stations (e.g., master node 201 or secondary node 202 in Figure 2), or devices contained therein. Referring to Figure 10, a message is sent to the terminal device (UE) indicating a configuration for beam fault recovery associated with the SCG (1001). This configuration indicates to the UE to trigger a beam fault recovery procedure for at least one cell of the SCG in response to the activation of the SCG, if one or more predefined conditions are met. One or more predefined conditions may include, for example, at least one of a first predefined condition and / or a second predefined condition, as described above with reference to Figure 5.

[0088] Figure 11 shows a flowchart according to another exemplary embodiment, where BFD-related parameters such as beamFailureInstanceMaxCount and beamFailureDetectionTimer may be configured separately for an inactive SCG compared to an activated SCG. The BFD-related parameters may include one or more reference signals used for BFD. For example, if the period of the BFD reference signal differs in the inactive SCG state compared to the activated SCG state, the network may configure smaller values ​​for beamFailureInstanceMaxCount and beamFailureDetectionTimer in the inactive SCG state compared to the activated SCG state. The functions shown in Figure 11 may be performed by devices such as network elements, such as base stations (e.g., master node 201 or secondary node 202 in Figure 2), or devices included therein. Referring to Figure 11, while the SCG is activated, a first set of parameters for performing beam fault detection for at least one cell of the SCG is sent to the UE (1101). In other words, the first set of parameters is used by the UE while the SCG is in an activated state. The first set of parameters includes at least a first beam fault detection timer and a first beam fault instance threshold for the activated SCG. While the SCG is deactivated, a second set of parameters is sent to the UE for performing beam fault detection for at least one cell of the SCG (1102). In other words, the second set of parameters is used by the UE while the SCG is in an inactivated state. The second set of parameters includes at least a second beam fault detection timer and a second beam fault instance threshold for the inactivated SCG. The first set of parameters and the second set of parameters may be sent simultaneously or separately.

[0089] The functions and / or blocks described above using Figures 3 to 11 are not in absolute chronological order; some of them may be executed simultaneously, or in an order different from the one described. Other functions and / or blocks may also be executed between or within them.

[0090] In an exemplary embodiment, for a given serving cell configured with BFD, if a BFI indication is received from a lower layer, the MAC entity may start or restart a timer called beamFailureDetectionTimer and increment BFI_COUNTER by 1. If BFI_COUNTER is greater than or equal to beamFailureInstanceMaxCount, and the cell group associated with this MAC entity is not deactivated, or a reconfiguration is received to activate the cell group associated with this MAC entity, a BFR may be triggered on the serving cell if the serving cell is a SCell. If the serving cell is not a SCell, a random access procedure may be initiated on the SpCell.

[0091] In other exemplary embodiments, for a given serving cell configured with BFD, if a BFI indication is received from a lower layer, the MAC entity may start or restart a timer called beamFailureDetectionTimer. If a reconfiguration is received to activate the cell group associated with this MAC entity, and a beam failure is detected on a SpCell while the cell group associated with this MAC entity was deactivated, a random access procedure may be started on the SpCell. Otherwise, BFI_COUNTER is incremented by 1. If the incremented BFI_COUNTER is greater than or equal to beamFailureInstanceMaxCount, a beam failure is considered to have been detected on this serving cell. If BFI_COUNTER is greater than or equal to beamFailureInstanceMaxCount and the cell group associated with this MAC entity is not deactivated, a BFR may be triggered on this serving cell if the serving cell is a SCell. Otherwise, if the serving cell is a SpCell and the cell group associated with this MAC entity is not deactivated, a random access procedure may be started on the SpCell.

[0092] The technical advantages provided by some exemplary embodiments include the potential to reduce the UE's power consumption and network resource consumption by preventing the UE from executing random access procedures for BFR during SCG activation when such procedures are not required. If a beam failure is detected while the SCG is deactivated, the previously serving beam may already be recovered by the UE (for example, the beamFailureDetectionTimer may have expired). If the TAT is still operating and one or more beams have been recovered after the beam failure, unnecessary random access procedures can be avoided during SCG activation.

[0093] Figure 12 shows an exemplary embodiment of apparatus 1200, which may be an apparatus such as a terminal device or an apparatus included in a terminal device. A terminal device may also be referred to herein as a UE or user equipment. Apparatus 1200 comprises a processor 1210. The processor 1210 interprets computer program instructions and processes data. The processor 1210 may comprise one or more programmable processors. The processor 1210 may comprise programmable hardware having embedded firmware, and alternatively or additionally, one or more application-specific integrated circuits (ASICs).

[0094] The processor 1210 is coupled to the memory 1220. The processor is configured to read and write data to the memory 1220. The memory 1220 may comprise one or more memory units. The memory units may be volatile or non-volatile. Note that in some exemplary embodiments, there may be one or more units of non-volatile memory and one or more units of volatile memory, or one or more units of non-volatile memory, or one or more units of volatile memory. Volatile memory may be, for example, random access memory (RAM), dynamic random access memory (DRAM), or synchronous dynamic random access memory (SDRAM). Non-volatile memory may be, for example, read-only memory (ROM), programmable read-only memory (PROM), electronically erasable programmable read-only memory (EEPROM), flash memory, optical storage, or magnetic storage. In general, memory may be referred to as a non-temporary computer-readable medium. The memory 1220 stores computer-readable instructions executed by the processor 1210. For example, non-volatile memory stores computer-readable instructions, and processor 1210 uses volatile memory for temporary storage of data and / or instructions to execute the instructions.

[0095] Computer-readable instructions may be pre-stored in memory 1220, or alternatively or additionally, received by the device via electromagnetic carrier signals and / or copied from a physical entity such as a computer program product. When a computer-readable instruction is executed, the device 1200 performs one or more of the functions described above.

[0096] In the context of this document, “memory” or “computer-readable medium” or “computer-readable medium” can be any non-temporary medium or multiple mediums or means that can contain, store, communicate, propagate or transport instructions used by an instruction execution system, apparatus, or device, such as a computer, or instructions used in connection therewith.

[0097] The device 1200 may further comprise, or be connected to, an input unit 1230. The input unit 1230 may comprise one or more interfaces for receiving input. One or more interfaces may comprise, for example, one or more temperature sensors, motion sensors and / or orientation sensors, one or more cameras, one or more accelerometers, one or more microphones, one or more buttons, and / or one or more touch detection units. Furthermore, the input unit 1230 may comprise an interface to which an external device can be connected.

[0098] The device 1200 may include an output unit 1240. The output unit may include, or be connected to, one or more displays capable of rendering visual content, such as light-emitting diode (LED) displays, liquid crystal displays (LCDs), and / or liquid crystal on silicon (LCoS) displays. The output unit 1240 may further include one or more audio outputs. One or more audio outputs may be, for example, loudspeakers.

[0099] The device 1200 further comprises a connection unit 1250. The connection unit 1250 enables wireless connectivity to one or more external devices. The connection unit 1250 comprises at least one transmitter and at least one receiver, which may be integrated into or to which the device 1200 can be connected. The at least one transmitter comprises at least one transmitting antenna, and the at least one receiver comprises at least one receiving antenna. The connection unit 1250 may comprise an integrated circuit or set of integrated circuits that provide wireless communication functionality to the device 1200. Alternatively, the wireless connectivity may be a hardwired application-specific integrated circuit (ASIC). The connection unit 1250 may comprise one or more components, such as a power amplifier, a digital front-end (DFE), an analog-to-digital converter (ADC), a digital-to-analog converter (DAC), a frequency converter, a modulator / demodulator, and / or an encoder / decoder circuit, which are controlled by a corresponding control unit.

[0100] It should be noted that the device 1200 may further comprise various components not shown in Figure 12. These various components may be hardware components and / or software components.

[0101] The device 1300 in Figure 13 shows an exemplary embodiment of a device such as a base station, or a device included in a base station. A base station may be called, for example, a network element, RAN node, master node, secondary node, NodeB, LTE evolved NodeB (eNB), gNB, NR base station, 5G base station, access node, access point (AP), distributed unit (DU), central unit (CU), baseband unit (BBU), radio unit (RU), radio head, remote radio head (RRH), or transmit / receive point (TRP). The device may comprise, for example, a circuit or chipset applicable to a base station to implement some of the exemplary embodiments described. The device 1300 may be an electronic device comprising one or more electronic circuits. The device 1300 may comprise a communication control circuit 1310, such as at least one processor, and at least one memory 1320 containing computer program code (software) 1322, the at least one memory and the computer program code (software) 1322 configured to cause the device 1300 to execute some of the exemplary embodiments described above using at least one processor.

[0102] The processor is coupled to memory 1320. The processor is configured to read and write data to memory 1320. Memory 1320 may comprise one or more memory units. Memory units may be volatile or non-volatile. Note that in some exemplary embodiments, there may be one or more units of non-volatile memory and one or more units of volatile memory, or one or more units of non-volatile memory, or one or more units of volatile memory. Volatile memory may be, for example, random access memory (RAM), dynamic random access memory (DRAM), or synchronous dynamic random access memory (SDRAM). Non-volatile memory may be, for example, read-only memory (ROM), programmable read-only memory (PROM), electronically erasable programmable read-only memory (EEPROM), flash memory, optical storage, or magnetic storage. Generally, memory may be referred to as non-temporary computer-readable medium. Memory 1320 stores computer-readable instructions that are executed using the processor. For example, non-volatile memory stores computer-readable instructions, and the processor uses volatile memory for temporary storage of data and / or instructions to execute the instructions.

[0103] Computer-readable instructions may be pre-stored in memory 1320, or alternatively or additionally, received by the device via electromagnetic carrier signals and / or copied from a physical entity such as a computer program product. When a computer-readable instruction is executed, the device 1300 performs one or more of the functions described above.

[0104] The memory 1320 can be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and / or removable memory. The memory may include a configuration database for storing configuration data. For example, the configuration database may store the current list of adjacent cells and, in some exemplary embodiments, the structure of the frames used by the detected adjacent cells.

[0105] The device 1300 may further include a communication interface 1330 having hardware and / or software for realizing a communication connection according to one or more communication protocols. The communication interface 1330 includes at least one transmitter (TX) and at least one receiver (RX) which can be integrated into or to which the device 1300 can be connected. The communication interface 1330 provides the device with wireless communication capabilities for communication in a cellular communication system. The communication interface may, for example, provide a wireless interface to a terminal device. The device 1300 may further include other interfaces to a core network, such as a network coordinator device, and / or access nodes of a cellular communication system. The device 1300 may further include a scheduler 1340 configured to allocate resources.

[0106] The following describes some examples of this solution.

[0107] Example 1: An apparatus comprising at least one processor and at least one memory containing computer program code, wherein the at least one memory and the computer program code are configured to cause the apparatus to use the at least one processor to perform a beam fault recovery procedure for at least one cell of a secondary cell group in response to activating the secondary cell group when one or more predefined conditions are met.

[0108] Example 2: The apparatus according to Example 1, wherein the one or more predefined conditions include at least one of a first predefined condition and a second predefined condition, the first predefined condition is satisfied when the secondary cell group is activated if the beam fault instance counter associated with the at least one cell is greater than or equal to the beam fault instance threshold, and the second predefined condition is satisfied when the secondary cell group is activated if the beam fault detection timer associated with the at least one cell is operating.

[0109] Example 3: The apparatus according to Example 2, wherein the second predefined condition is met when a beam fault is detected in at least one cell while the secondary cell group is deactivated, and the beam fault detection timer is operating when the secondary cell group is activated.

[0110] Example 4: The apparatus according to Prior Example 2 or 3, wherein the apparatus is further configured to determine that the beam fault instance counter is greater than or equal to the beam fault instance threshold while the secondary cell group is deactivated, and to wait until the secondary cell group is activated before triggering the beam fault recovery procedure.

[0111] Example 5: The apparatus according to any of the prior examples 1 to 4, wherein the apparatus is further capable of detecting a beam fault in at least one cell while the secondary cell group is deactivated, and, when the beam fault is detected while the secondary cell group is deactivated, triggering a time alignment timer associated with the at least one cell to expire.

[0112] Example 6: The apparatus according to any one of Examples 1 to 4, wherein the apparatus can be made to detect a beam fault in at least one cell while the secondary cell group is deactivated, and to trigger a time alignment timer associated with at least one cell to expire in response to activating the secondary cell group.

[0113] Example 7: The apparatus according to Example 5 or 6, wherein the apparatus can be made to stop performing beam fault detection in at least one cell when the time alignment timer expires.

[0114] Example 8: The apparatus according to Example 7, wherein beam fault detection is stopped when the time alignment timer expires if no contention-free random access resources are configured.

[0115] Example 9: The apparatus according to any of the prior examples 1 to 8, wherein the apparatus can be further made to indicate beam faults detected in at least one cell of the secondary cell group via the master cell group.

[0116] Example 10: The apparatus according to any of the prior examples 1 to 9, wherein the apparatus can be made to activate the secondary cell group in response to an indication received from a network element of a wireless communication network or in response to an internal trigger.

[0117] Example 11: An apparatus comprising at least one processor and at least one memory containing computer program code, wherein the at least one memory and the computer program code are configured to use the at least one processor to cause the apparatus to send a message to a terminal device indicating a configuration for beam fault recovery associated with a secondary cell group, the configuration indicating that, if one or more predefined conditions are met, the secondary cell group will be activated, triggering a beam fault recovery procedure for at least one cell of the secondary cell group.

[0118] Example 12: The apparatus according to Example 11, wherein the one or more predefined conditions include at least one of a first predefined condition and a second predefined condition, the first predefined condition is satisfied when the secondary cell group is activated if the beam fault instance counter associated with the at least one cell is greater than or equal to a first beam fault instance threshold, and the second predefined condition is satisfied when the secondary cell group is activated if the first beam fault detection timer associated with the at least one cell is operating.

[0119] Example 13: The apparatus according to Example 12, wherein the second predefined condition is met when a beam fault is detected in at least one cell while the secondary cell group is deactivated, and the first beam fault detection timer is operating when the secondary cell group is activated.

[0120] Example 14: The apparatus according to any one of Examples 11 to 13, wherein the configuration further indicates that if a beam fault is detected in at least one cell while the secondary cell group is deactivated, the time alignment timer should be expired.

[0121] Example 15: The apparatus according to any one of Examples 11 to 13, wherein the configuration further indicates that if a beam fault is detected in at least one cell while the secondary cell group is deactivated, the time alignment timer should be allowed to expire when activating the secondary cell group.

[0122] Example 16: The apparatus according to any one of Examples 11 to 15, wherein the apparatus is further configured to transmit to the terminal device a first set of parameters for performing beam fault detection on at least one cell while the secondary cell group is activated, the first set of parameters comprising at least a first beam fault detection timer and a first beam fault instance threshold, and transmit to the terminal device a second set of parameters for performing beam fault detection on at least one cell while the secondary cell group is deactivated, the second set of parameters comprising at least a second beam fault detection timer and a second beam fault instance threshold.

[0123] Example 17: The apparatus according to any of the prior examples 11 to 16, wherein the at least one cell includes at least one special cell, a primary secondary cell, and a secondary cell.

[0124] Example 18: A method comprising triggering a beam fault recovery procedure for at least one cell in a secondary cell group in response to activating a secondary cell group when one or more predefined conditions are met.

[0125] Example 19: A method comprising sending a message to a terminal device indicating a configuration for beam fault recovery associated with a secondary cell group, wherein the configuration indicates that, if one or more predefined conditions are met, a beam fault recovery procedure will be triggered for at least one cell of the secondary cell group in response to activating the secondary cell group.

[0126] Example 20: A computer program comprising instructions, wherein the instructions cause a device to activate a secondary cell group if at least one or more predefined conditions are met, and in response, trigger a beam fault recovery procedure for at least one cell in the secondary cell group.

[0127] Example 21: A computer program comprising instructions, the instructions causing a device to send a message to a terminal device indicating a configuration for beam fault recovery associated with a secondary cell group, the configuration indicating that, if one or more predefined conditions are met, the secondary cell group will be activated, triggering a beam fault recovery procedure for at least one cell of the secondary cell group.

[0128] Example 22: A system comprising at least a terminal device and a network element of a wireless communication network, wherein the network element is configured to send a message to the terminal device indicating a configuration for beam fault recovery associated with a secondary cell group, the configuration indicating that, if one or more predefined conditions are met, a beam fault recovery procedure is triggered for at least one cell of the secondary cell group in response to activating the secondary cell group, and the terminal device is configured to receive the message indicating the configuration from the network element and, if one or more predefined conditions are met, trigger the beam fault recovery procedure for at least one cell of the secondary cell group in response to activating the secondary cell group.

[0129] As used in this application, the term "circuit" may refer to one, more, or all of the following: (a) Hardware-only circuit embodiments (analog and / or digital circuit-only embodiments). (b) A combination of hardware circuitry and software, for example (if applicable) (i) A combination of analog and / or digital hardware circuitry(s) and software / firmware. (ii) Any part of a software-based hardware processor(s) (including digital signal processors(s)), software, and memory(s) that works in conjunction to enable a device such as a mobile phone to perform various functions. (c) Hardware circuits and / or processors, such as microprocessors or parts of microprocessors, that require software (e.g., firmware) for operation but may not have software when not required for operation.

[0130] This definition of “circuit” applies to all use of the term in this application, including in all claims. Further examples include, as used in this application, a mere hardware circuit or processor (or more processors), or a portion of a hardware circuit or processor, as well as an embodiment of the software and / or firmware associated therewith. The term “circuit” also includes, for example, a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or network device, where applicable to the elements of a particular claim.

[0131] The techniques and methods described herein can be implemented by various means. For example, these techniques can be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or a combination thereof. In the case of hardware embodiments, the apparatus(s) of the exemplary embodiments may be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), graphics processing units (GPUs), processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof. In the case of firmware or software, implementation can be done via at least one chipset module (e.g., a procedure, a function, etc.) that performs the functions described herein. The software code may be stored in a memory unit and executed using a processor. The memory unit may be implemented within the processor or outside the processor. In the latter case, it may be communicatively coupled to the processor via various means known in the art. Furthermore, the components of the system described herein may be reconfigured and / or supplemented with additional components to facilitate the realization of various embodiments described herein, and are not limited to the exact configuration shown in the provided drawings, as will be understood by those skilled in the art.

[0132] As technology advances, it will be apparent to those skilled in the art that the concepts of the present invention can be realized in various ways. The embodiments are not limited to the exemplary embodiments described above, but can be modified within the scope of the claims. Therefore, all words and expressions should be interpreted broadly and are intended to illustrate, not limit, the exemplary embodiments.

Claims

1. A device comprising at least one processor and at least one memory containing computer program code, wherein the at least one memory and the computer program code are used by the at least one processor to power the device. Upon receiving a secondary cell group activation indication, it is determined whether the value of the beam fault instance counter associated with at least one cell in the secondary cell group is greater than or equal to the beam fault instance threshold, At a minimum, triggering a beam fault recovery procedure for the at least one cell in the secondary cell group based on determining that the value of the beam fault instance counter associated with the at least one cell in the secondary cell group is greater than or equal to the beam fault instance threshold, The apparatus configured to perform the following.

2. The aforementioned device further, Upon receiving the secondary cell group activation indication, and based on the determination that the beam fault detection timer associated with at least one cell of the secondary cell group is operating, the beam fault recovery procedure for at least one cell of the secondary cell group is triggered. The apparatus according to claim 1, which can be made to perform the following actions.

3. The aforementioned device is To trigger the beam fault recovery procedure for the at least one cell of the secondary cell group, upon receiving the secondary cell group activation indication, it is required that the beam fault detection timer associated with the at least one cell of the secondary cell group is operating, and that the value of the beam fault instance counter associated with the at least one cell of the secondary cell group is greater than or equal to the beam fault instance threshold. The apparatus according to claim 1, which can be made to perform the following actions.

4. The aforementioned device further, While the secondary cell group is deactivated, a beam fault is detected in at least one cell of the secondary cell group. If a beam fault is detected while the secondary cell group is deactivated, the time alignment timer associated with at least one cell in the secondary cell group is triggered to expire. The apparatus according to claim 1, which can be made to perform the following actions.

5. The aforementioned device further, While the secondary cell group is deactivated, a beam fault is detected in at least one cell of the secondary cell group. In response to receiving the secondary cell group activation indication, trigger the time alignment timer associated with at least one of the cells to expire. The apparatus according to claim 1, which can be made to perform the following actions.

6. The aforementioned device further, When the time alignment timer expires, stop performing beam fault detection in at least one cell of the secondary cell group. The apparatus according to claim 4 or 5, which can be made to perform the following.

7. The apparatus according to claim 6, wherein the apparatus is configured to stop beam fault detection when the time alignment timer expires if no contention-free random access resources are configured.

8. The aforementioned device further, To indicate a beam fault detected in at least one cell of the secondary cell group via the master cell group, The apparatus according to claim 1, which can be made to perform the following actions.

9. The aforementioned device further, Activating the secondary cell group in response to the secondary cell group activation indication received from a network element of the wireless communication network, or in response to an internal trigger. The apparatus according to claim 1, which can be made to perform the following actions.

10. The apparatus according to claim 1, wherein the apparatus is configured to receive the secondary cell group activation indication from the master node via the master cell group.

11. The apparatus according to claim 1, wherein the apparatus is configured to trigger the beam fault recovery procedure by executing a random access (RA) procedure.

12. The at least one cell includes the primary secondary cell (PSCell) of the secondary cell group, The apparatus according to claim 11, wherein the apparatus is configured to trigger the beam fault recovery procedure by executing the RA procedure on the PSCell.

13. The apparatus according to claim 12, wherein the apparatus is configured to execute the RA procedure by transmitting a random access preamble to the PSCell.

14. A device comprising at least one processor and at least one memory containing computer program code, wherein the at least one memory and the computer program code are used by the at least one processor to power the device. Sending a message to user equipment indicating the configuration for beam fault recovery associated with the secondary cell group. It is configured to execute, The device, upon receiving a secondary cell group activation indication, indicates that it determines whether the value of a beam fault instance counter associated with at least one cell in the secondary cell group is greater than or equal to a beam fault instance threshold, and that it triggers a beam fault recovery procedure for at least one cell in the secondary cell group based on the determination that the value of the beam fault instance counter associated with at least one cell in the secondary cell group is greater than or equal to a beam fault instance threshold.

15. The apparatus according to claim 14, further comprising the configuration indicating that upon receiving the secondary cell group activation indication, the apparatus also determines that a beam fault detection timer associated with the at least one cell of the secondary cell group is operating, and thereby triggers the beam fault recovery procedure for the at least one cell of the secondary cell group.

16. The apparatus according to claim 14, wherein, upon receiving the secondary cell group activation indication, the configuration further indicates that, in order to trigger the beam fault recovery procedure for the at least one cell of the secondary cell group, the beam fault detection timer associated with the at least one cell of the secondary cell group is operating and the value of the beam fault instance counter associated with the at least one cell of the secondary cell group is greater than or equal to a beam fault instance threshold.

17. The apparatus according to any one of claims 14 to 16, further comprising the configuration indicating that if a beam fault is detected in at least one cell while the secondary cell group is deactivated, the time alignment timer should be expired.

18. The apparatus according to any one of claims 14 to 16, further comprising the configuration indicating that if a beam fault is detected in at least one cell while the secondary cell group is deactivated, the time alignment timer should expire to receive the secondary cell group activation indication.

19. Transmitting the secondary cell group activation indication to the user device, The apparatus according to any one of claims 14 to 16, which can be further carried out.

20. The aforementioned device further, While the secondary cell group is activated, transmit to the user equipment a first set of parameters for performing beam fault detection in at least one cell, wherein the first set of parameters includes at least a first beam fault detection timer and a first beam fault instance threshold. The transmission to the user equipment a second set of parameters for performing beam fault detection in at least one cell while the secondary cell group is deactivated, wherein the second set of parameters includes at least a second beam fault detection timer and a second beam fault instance threshold. The apparatus according to any one of claims 14 to 16, which can be made to perform the following.

21. The apparatus according to claim 1 or 14, wherein the at least one cell includes at least one of a special cell, a primary secondary cell, and a secondary cell.

22. It is a method, Upon receiving a secondary cell group activation indication, the user equipment determines whether the value of the beam fault instance counter associated with at least one cell in the secondary cell group is equal to or greater than the beam fault instance threshold, At a minimum, triggering a beam fault recovery procedure for at least one cell in a secondary cell group based on determining that the value of a beam fault instance counter associated with at least one cell in the secondary cell group is greater than or equal to a beam fault instance threshold, The method, including the method described above.

23. It is a method, Sending a message to user equipment via a network element that indicates the configuration for beam fault recovery associated with the secondary cell group. Includes, The method, wherein the configuration indicates, upon receiving a secondary cell group activation indication, that it determines whether the value of a beam fault instance counter associated with at least one cell in the secondary cell group is greater than or equal to a beam fault instance threshold, and that it triggers a beam fault recovery procedure for at least one cell in the secondary cell group based on the determination that the value of a beam fault instance counter associated with at least one cell in the secondary cell group is greater than or equal to a beam fault instance threshold.

24. A computer program including instructions, wherein the instructions provide at least one device Upon receiving a secondary cell group activation indication, it is determined whether the value of the beam fault instance counter associated with at least one cell in the secondary cell group is greater than or equal to the beam fault instance threshold, At a minimum, triggering a beam fault recovery procedure for at least one cell in a secondary cell group based on determining that the value of a beam fault instance counter associated with at least one cell in the secondary cell group is greater than or equal to a beam fault instance threshold, The computer program described above is intended to execute [the specified action].

25. A computer program including instructions, wherein the instructions provide at least one device Sending a message to user equipment indicating the configuration for beam fault recovery associated with the secondary cell group. This is to make it happen. The computer program, upon receiving a secondary cell group activation indication, indicates that it determines whether the value of a beam fault instance counter associated with at least one cell in the secondary cell group is greater than or equal to a beam fault instance threshold, and that it triggers a beam fault recovery procedure for at least one cell in the secondary cell group based on the determination that the value of the beam fault instance counter associated with at least one cell in the secondary cell group is greater than or equal to a beam fault instance threshold.

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