Enhanced uplink handover for multi-receiver user equipment upon beam failure

Abstract

A method is provided that includes monitoring radio link quality at a user equipment connected to both a first transmit receive point (TRP) and a second TRP of a network. The user equipment has a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but has an uplink (UL) connection with the second TRP instead of the UL connection with the first TRP, and the monitored radio link quality is the radio link quality of the second DL connection with the second TRP. The method comprises identifying a condition for switching the UL connection based at least on a radio link quality of the second DL connection, and switching the UL connection from the second TRP to the first TRP based on the determination.

Description

Technical Field

[0001] The present disclosure relates generally to telecommunications, and in particular to preventing or responding to uplink beam failure for multi-receiver user equipment in a telecommunications system. Background Art

[0002] A telecommunication system may be viewed as a facility for enabling communication sessions between two or more entities (such as user terminals, base stations, and / or other nodes) by providing carrier waves between the various entities involved in the communication path. For example, a telecommunication system may be provided by a communication network and one or more compatible communication devices. A communication session may include, for example, data communications for bearer communications, such as voice, video, electronic mail (email), text messaging, multimedia, and / or content data, etc. Non-limiting examples of the services provided include two-way or multi-way calls, data communications or multimedia services, and access to data network systems (such as the Internet).

[0003] In a wireless telecommunications system, at least a portion of a communication session between at least two stations takes place over a wireless link. Examples of wireless systems include public land mobile networks (PLMNs), satellite-based communication systems, and different wireless local area networks, such as wireless local area networks (WLANs). Some wireless systems may be divided into cells, and are therefore often referred to as cellular systems.

[0004] A user can access the telecommunication system through an appropriate communication device or terminal. The user's communication device may be referred to as a user equipment (UE) or user device. The communication device is equipped with appropriate signal receiving and sending means for implementing communications, such as implementing access to a communication network or communicating directly with other users. The communication device can access a carrier provided by a station (e.g., a base station of a cell) and send and / or receive communications on the carrier.

[0005] Telecommunication systems and related equipment typically operate according to a given standard or specification, which specifies what the various entities associated with the system are allowed to do and how it should be achieved. Communication protocols and / or parameters for the connection are also typically defined. An example of a telecommunication system is the Universal Mobile Telecommunications System (UMTS). Other examples of telecommunication systems are Long Term Evolution (LTE), Advanced LTE, and so-called 5G or New Radio (NR) networks. NR is being standardized by the Third Generation Partnership Project (3GPP). Summary of the invention

[0006] Example implementations of the present disclosure are directed to telecommunications and, in particular, to preventing or responding to uplink beam failures of multi-receiver user equipment in telecommunications systems.In this regard, the present disclosure includes, but is not limited to, the following example implementations.

[0007] Some example implementations provide a method comprising: monitoring radio link quality at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP respectively, but having an uplink (UL) connection with the second TRP and not having a UL connection with the first TRP, the monitored radio link quality being the radio link quality of the second DL connection with the second TRP; identifying a condition for switching the UL connection based at least on the radio link quality of the second DL connection; and switching the UL connection from the second TRP to the first TRP based on the determination.

[0008] Some example implementations provide a method comprising: collecting operational information at a network including a first transmission reception point (TRP) and a second TRP, the operational information including information related to one or more of the first TRP, the second TRP, or a user device connected to both the first TRP and the second TRP, the user device having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but having an uplink (UL) connection with the second TRP and not having a UL connection with the first TRP; performing an evaluation of the operational information of a potential UL failure at either the first TRP or the second TRP; and making a determination at the network based on the evaluation whether to switch the UL connection from the second TRP to the first TRP.

[0009] Some example implementations provide a method comprising: detecting a beam failure at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but having a UL connection with the second TRP and not having a UL connection with the first TRP, the beam failure being a beam failure of the second DL connection with the second TRP; performing an evaluation of a UL condition of the first TRP; making a determination based on the evaluation to switch the UL connection from the second TRP to the first TRP or a third TRP; and switching the UL connection from the second TRP to the first TRP or the third TRP based on the determination.

[0010] Some example implementations provide a method comprising: detecting a beam failure at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP respectively, but having a UL connection with the second TRP and not having a UL connection with the first TRP, the beam failure being a beam failure of the first DL connection with the first TRP; evaluating a propagation delay difference between the first TRP and the second TRP; making a determination based on the propagation delay difference whether to perform a beam recovery process to recover the first DL connection using the first TRP or through the UL connection with the second TRP; and performing a beam recovery process based on the determination.

[0011] These and other features, aspects and advantages of the present disclosure will become apparent by reading the following detailed description and the accompanying drawings, which will be briefly described below. The present disclosure includes any combination of two, three, four or more features or elements set forth in the present disclosure, regardless of whether such features or elements are explicitly combined or otherwise referenced in the specific example implementations described herein. The present disclosure is intended to be read as a whole, so that any separable features or elements of the present disclosure should be considered combinable in any aspect and example implementation thereof, unless the context of the present disclosure clearly provides otherwise.

[0012] Therefore, it should be understood that the present disclosure is provided only to summarize some example implementations in order to provide a basic understanding of some aspects of the present disclosure. Therefore, it should be understood that the above-mentioned example implementations are merely examples and should not be interpreted as narrowing the scope or spirit of the present disclosure in any way. Other example implementations, aspects and advantages will become clear through the following detailed description in conjunction with the accompanying drawings, which illustrate the principles of some of the described example implementations by way of example. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Having generally described example implementations of the present disclosure, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and in which:

[0014] Figure 1 A telecommunications system including one or more public land mobile networks (PLMNs) coupled to one or more external data networks is illustrated according to some example implementations of the present disclosure;

[0015] Figure 2 illustrates deployment of a PLMN according to some example implementations;

[0016] Figure 3 illustrates an example of multi-TRP (Transmission Reception Point) communications according to some example implementations;

[0017] Figure 4illustrates a high speed train (HST) scenario according to some example implementations, in which the possibility of beam failure can be addressed;

[0018] Figure 5 illustrates a graph of reference signal received power (RSRP) versus distance along an HST track to illustrate potential locations where link failures exist, which may be addressed by some example implementations;

[0019] Figure 6 is a signaling diagram for preventing uplink (UL) outage according to some example implementations;

[0020] Figure 7 is a signaling diagram for preventing UL outage according to some example implementations, which uses experience-based information from the network side to predict the potential need for UL switching;

[0021] Fig. 8A and Figure 8B is a signaling diagram for responding to beam failure by autonomously adjusting UL transmit timing according to some example implementations;

[0022] Fig. 9 is a signaling diagram for recovering a downlink (DL) connection with one TRP using a UL connection with another TRP according to some example implementations;

[0023] Fig. 10A and Fig. 10B is a flow chart illustrating various steps in a method according to various example implementations;

[0024] Fig.11A and Fig. 11B is a flow chart illustrating various steps in another method according to various example implementations;

[0025] Fig. 12A , Fig. 12B , Fig. 12C , Fig.12D and Fig.12E is a flow chart illustrating various steps in another method according to various example implementations;

[0026] Fig.13A and Fig. 13B is a flowchart illustrating various steps in another method according to various example implementations; and

[0027] Fig.14 Apparatus according to some example implementations are illustrated. DETAILED DESCRIPTION

[0028] Some implementations of the present disclosure will now be described more fully below with reference to the accompanying drawings, in which some but not all implementations of the present disclosure are shown. In fact, various implementations of the present disclosure may be embodied in many different forms and should not be construed as being limited to the implementations described herein; rather, these example implementations are provided to make the present disclosure thorough and complete and will fully convey the scope of the present disclosure to those skilled in the art. The same reference numerals refer to the same elements throughout.

[0029] Unless otherwise specified or clear from the context, references to first, second, etc. should not be construed as implying a particular order. A feature described as being above another feature (unless otherwise specified or clear from the context) may be located below the other feature, and vice versa; and similarly, a feature described as being to the left of another feature may instead be to the right, and vice versa. Furthermore, although reference may be made herein to quantitative measurements, values, geometric relationships, and the like, any one or more (if not all) of these may be absolute or approximate, unless otherwise specified, to take into account acceptable variations that may occur, such as variations due to engineering tolerances, and the like.

[0030] As used herein, unless otherwise specified or clear from the context, an "or" of a set of operands is an "inclusive or," and thus is true only when one or more of the operands are true, whereas an "exclusive or" is false when all operands are true. Thus, for example, "[A] or [B]" is true if [A] is true, or if [B] is true, or if both [A] and [B] are true. In addition, the articles "a" and "an" mean "one or more," unless otherwise specified or the context clearly directs to the singular. Furthermore, it should be understood that the terms "data," "content," "digital content," and "information," and similar terms, are sometimes used interchangeably unless otherwise specified. The term "network" may refer to a group of interconnected computers, including clients and servers; within a network, these computers may be interconnected directly or indirectly in a variety of ways, including via one or more switches, routers, gateways, access points, and the like.

[0031] Reference may be made herein to specific systems, architectures, etc., but it should be understood that example implementations of the present disclosure are equally applicable to any of a plurality of systems, architectures, etc. For example, reference may be made to 3GPP technologies such as Global System for Mobile Communications (GSM), UMTS, LTE, LTE-Advanced, and 5G NR; however, it should be understood that example implementations of the present disclosure may be equally applicable to non-3GPP technologies such as IEEE 802, Bluetooth, and Bluetooth Low Energy.

[0032] In addition, as used in this application, the term "circuitry" may refer to one or more or all of the following: (a) a pure hardware circuit implementation (e.g., an implementation solely in analog and / or digital circuitry); (b) a combination of hardware circuitry and software, such as (as applicable): (i) a combination of (multiple) analog and / or digital hardware circuits with software / firmware, and (ii) any portion of (multiple) hardware processors (including (multiple) digital signal processors), software, and (multiple) memories with software that work together to enable a device such as a mobile phone or server to perform various functions); or (c) (multiple) hardware circuits and / or (multiple) processors, such as (multiple) microprocessors or portions of (multiple) microprocessors, which require software (e.g., firmware) to run, but the software may not be present when it is not required to run.

[0033] The above definition of circuitry applies to all uses of the term in this application, including in any claims. As another example, as used in this application, the term circuitry also covers an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its accompanying software and / or firmware. For example, if applicable to a particular claim element, the term circuitry also covers 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.

[0034] Figure 1 A telecommunications system 100 implemented according to various examples of the present disclosure is illustrated. A telecommunications system typically includes one or more telecommunications networks. As shown, for example, the system includes one or more public land mobile networks (PLMNs) 102, which are coupled to one or more other external data networks 104, particularly including a wide area network (WAN), such as the Internet. Each of the PLMNs includes a core network (CN) 106 backbone, such as the Evolved Packet Core (EPC) of LTE, a 5G Core Network (5GC), etc.; and each of the core network and the Internet is coupled to one or more radio access networks (RAN) 108, air interfaces, etc. that implement one or more radio access technologies (RATs). As used herein, "network equipment" refers to any suitable equipment on the network side of a telecommunications network. Examples of suitable network equipment will be described in more detail below.

[0035] In addition, the system includes one or more radio units, which may be variously referred to as user equipment (UE) 110, terminal equipment (device), terminal equipment (equipment), mobile station, etc. UE is generally a device configured to communicate with a network device or another UE in a telecommunications network. UE can be a portable computer (e.g., laptop, notebook, tablet), a mobile phone (e.g., mobile phone, smart phone), a wearable computer (e.g., smart watch), etc. In other examples, UE can be customer premises equipment (CPE). In other examples, UE can be an Internet of Things (IoT) device, an Industrial Internet of Things (IIoT device), a vehicle equipped with vehicle-to-everything (V2X) communication technology, etc.

[0036] In operation, the UE 110 may be configured to connect to one or more RANs 108 according to its specific radio access technology, thereby accessing a specific CN 106 of the PLMN 102, or accessing one or more external data networks 104 (e.g., the Internet). The external data network may be configured to provide Internet access, operator services, third-party services, etc. For example, the International Telecommunication Union (ITU) classifies 5G mobile network services into three categories: enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine type communications (mMTC) or massive Internet of Things (MIoT).

[0037] Examples of radio access technologies include 3GPP radio access technologies, such as GSM, UMTS, LTE, Advanced LTE, and 5G NR. Other examples of radio access technologies include IEEE 802 technologies, such as IEEE 802.11 (Wi-Fi), IEEE802.15 (including 802.15.1 (WPAN / Bluetooth), 802.15.4 (Zigbee), and 802.15.6 (WBAN)), Bluetooth, Bluetooth Low Energy (BLE), Ultra-Wideband (UWB), etc. In general, radio access technology may refer to any 2G, 3G, 4G, 5G or higher generation mobile communication technology and different versions thereof, as well as any other radio access technology that may be interconnected with such mobile communication technology to provide access to a mobile network operator (MNO) core network.

[0038] In various examples, the RAN 108 may be configured as one or more macro cells, micro cells, pico cells, femto cells, etc. The RAN may generally include one or more radio access nodes configured to interact with the UE 110. In various examples, the radio access node may be referred to as a base station (BS), an access point (AP), a base transceiver station (BTS), a node B (NB), an evolved NB (eNB), a macro BS, a NB (MNB) or an eNB (MeNB), a home BS, a NB or an eNB (HeNB), a next generation NB (gNB), a next generation eNB (ng-eNB), etc. A network control / management entity of some type responsible for controlling the radio access node. The network control / management entity and the radio access node may be separate or integrated into a single device. The network control / management entity may include a processing circuit system configured to perform various management functions, etc. The processing circuit system may be associated with a computer-readable storage medium or a database to maintain information required in the management function.

[0039] The RAN 108 may be centralized or distributed. In various examples, the components of the RAN may be interconnected via Ethernet, Gigabit Ethernet, Asynchronous Transfer Mode (ATM), optical fiber, dark fiber, passive wavelength division multiplexing (WDM), WDM passive optical network (WDM-PON), optical transport network (OTN), time sensitive network (TSN), and / or any other data link layer network (possibly including radio links). The RAN may be connected to the CN 106 via one or more gateways, network functions, etc.

[0040] As will be appreciated, the PLMN 102 may be deployed in a variety of different ways. Figure 2 A deployment 200 of a PLMN is illustrated according to some example implementations, such as a 4G LTE or 5G deployment. As shown, the deployment includes a CN 106 and a RAN 108 having one or more radio access nodes 202 configured to interact with a UE 110. In a 4G LTE deployment, the EPC is the CN and the Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) is the RAN; and the E-UTRAN includes one or more eNBs (radio access nodes) configured to connect the UE to the E-UTRAN, thereby accessing the EPC. Similarly, in a 5G deployment, the 5GC is the CN 106 and the Next Generation (NG) Radio Access Network (NG-RAN) is the RAN 108; and the NG-RAN includes one or more gNBs (radio access nodes 202) configured to connect the UE 110 to the NG-RAN, thereby accessing the 5GC. The term "gNB" in 5G may correspond to the eNB in ​​4G LTE.

[0041] Some deployments of 4G LTE and 5G are considered standalone (SA) deployments. Other deployments combine 4G LTE and 5G technologies and are called non-standalone (NSA) deployments. In some deployments, the E-UTRAN includes one or more ng-eNBs that are configured to communicate with the 5GC and may also be configured to communicate with one or more gNBs. Similarly, in another deployment, the NG-RAN may include one or more en-gNBs that are configured to communicate with the EPC and may also be configured to communicate with one or more eNBs. In various cases, a single UE 110, a dual-mode or multi-mode UE may support multiple (two or more) RANs and thereby be configured to connect to multiple RANs, such as 4G LTE and 5G.

[0042] In some deployments, the operation of the radio access node 202 may be distributed or functionally split into components, including one or more remote radio heads (RRHs) or radio units (RUs) and baseband units (BBUs); in some architectures, the BBU may be split into distributed units (DUs) and central / centralized units (CUs), such as servers, hosts, or nodes. In some architectures, the RRH / RUs and DUs may be collocated. Node operations may also be distributed between multiple servers, hosts, or nodes.

[0043] It should also be understood that the allocation of work between CN 106 operations and radio access node 202 operations may vary from implementation to implementation. Therefore, the 5G network architecture may be based on a so-called CU-DU split. One gNB-CU (central node) may control one or more gNB-DUs. The gNB-CU may control multiple spatially separated gNB-DUs that act at least as transmit / receive (Tx / Rx) nodes. However, in some example implementations, the gNB-DU (also referred to as DU) may include, for example, a radio link control (RLC), a media access control (MAC) layer, and a physical (PHY) layer, while the gNB-CU (also referred to as CU) may include layers above the RLC layer, such as a packet data convergence protocol (PDCP) layer, a radio resource control (RRC), and an Internet Protocol (IP) layer. Other functional splits are also possible. It is assumed that those skilled in the art are familiar with the OSI model and the functions within each layer.

[0044] In some example implementations, a server or CU may generate a virtual network through which the server communicates with the radio node. In general, a virtual network may involve the process of combining hardware and software network resources and network functions into a single software-based management entity (virtual network). Such a virtual network may provide a flexible distribution of operations between the server and the radio head / node. In practice, any digital signal processing task may be performed in the CU or DU, and the boundaries of responsibility transfer between the CU and DU may be selected based on the implementation.

[0045] In various cases, the UE 110 can be configured to operate using multiple antenna panels or beams, such as via multiple-input multiple-output (MIMO) technology, which can allow the UE to significantly increase its data rate capabilities. A feature related to this capability is called multiple TRPs (transmission reception points). This feature enables the network to communicate with the UE using multiple TRPs. In this regard, a TRP can be a set of geographically collocated antennas that support transmission point (TP) and / or reception point (RP) functionality. In various examples, the TRP can include a radio access node 202, a radio access node antenna, an RRH, a RH, a remote antenna of a radio access node, etc.

[0046] Related to multi-TRP communications, radio link monitoring and link recovery procedures have been defined to handle the case where beam failure (BF) occurs between the UE and a TRP. These procedures include TRP-specific link recovery to cover the case where the UE is able to receive from two TRPs simultaneously. TRP-specific link recovery can be more specific for multi-DCI scenarios, where on the downlink (DL), the Physical Downlink Control Channel (PDCCH) is configured to transmit from two TRPs and the Physical Downlink Shared Channel (PDSCH) is scheduled with separate downlink control information (DCI) on each link. But not all UEs support two simultaneous uplink connections, which limits the UE to a single uplink (UL) transmission to a single TRP. A UE configured with multi-DCI (mDCI) can connect to two TRPs in the DL.

[0047] Figure 3 An example of multi-TRP communication 300 according to some example implementations is illustrated. More specifically, Figure 3A UE 110 is illustrated connected to a first TRP (TRP1) 302A and a second TRP (TRP2) 302B, which may be a radio access node 202 or TRPs of a radio access node. As shown, TRP2 (the "anchor" TRP) may have both UL and DL connections to the UE 110, while TRP1 (the "secondary" TRP) has only a DL connection. In the example shown, the DL connection is shown to include PDCCH and PDSCH, and the UL connection is shown to include a physical uplink control channel (PUCCH) and a physical uplink shared channel (PUSCH). The UL and DL connections between the UE and TRP2 include PDCCH2 (with coresetpoolindex0), PDSCH2, PUSCH, PUCCH; and the DL connection between the UE and TRP1 includes PDCCH1 (with coresetpoolindex1) and PDSCH1.

[0048] Although this example illustrates two TRPs, it should be understood that some examples may involve more than two TRPs and more than one UL connection. For example, a UE may be connected to three TRPs in the DL and only to two of the three TRPs in the UL. It should also be understood that although the TRPs may belong to the same cell, in some examples the TRPs may be from different cells.

[0049] In TRP-specific beam failure and recovery, if the beam recovery procedure is triggered for any of the TRPs, a UE 110 equipped with a PUCCH transmission configuration with a link recovery request (LRR) resource may send a scheduling request (SR) for UL resources followed by a MAC control element (CE) that provides a beam index for the corresponding TRP that experienced the beam failure. This MAC CE may sometimes be referred to as a beam failure recovery (BFR) MAC CE. For a UE that is not equipped with a PUCCH transmission configuration with LRR resources, the UE may send a random access (RA) preamble for UL shared channel (SCH) resource application followed by a MAC CE that provides a beam index for the corresponding TRP that experienced the failure.

[0050] In certain contexts, TRP-specific beam failure and recovery may be complex, such as when the UE 110 is moving at high speed relative to the TRP 302A, 302B. For example, in high-speed train (HST) deployments employing mmWave frequencies, such as in frequency range 2 (FR2), some unique situations may be encountered. In this regard, in order to maintain line-of-sight (LoS) conditions, power class 6 (PC6) UEs (designed specifically for HST FR2 deployments) may be mounted on the roof of the train. Due to the high path loss at higher carrier frequencies and due to the need to achieve long inter-site distances (ISD) along the railway track, beamforming may be used on both the TRP side and the UE side. Therefore, beam management including beam failure detection (BFD) and BFR may be particularly useful in this case as well as in other high-speed mobility situations.

[0051] To simplify high-speed mobility, it can be assumed in HST FR2 deployment that a cell can be composed of multiple non-colocated TRPs, and multiple non-colocated TRPs can have the same physical cell identifier (PCI). The mobility of UE 110 between TRPs can be performed by beam changes (e.g., transmission configuration indicator (TCI) state switching for DL ​​and spatial relationship switching for UL). Handover (HO) of the UE can be used to switch from one cell to another. The typical distance between non-colocated TRPs can be about 700 meters.

[0052] While work on HST deployments continues, the UE 110 may still support only a single UL connection. Thus, the UE may have two antenna panels to connect to TRP1 302A and TRP2 302B on the DL side, and only one antenna panel may be used to connect to TRP2 on the UL side. In some HST deployments, such as those where railroad tracks pass through tunnels, the TRPs may be very close to the tracks, which presents greater challenges to the environment. The issue of supporting UL switching with large propagation delay differences in the event of beam failures in multi-TRP scenarios has come into focus. While UL switching implemented according to the examples of the present disclosure may provide improved performance in many cases, the challenges associated with high-speed mobility may be particularly beneficial.

[0053] In view of the above, it can be appreciated that timely switching of the UL from TRP2 302B to TRP1 302A may help maintain a continuous UL connection for the UE 110. However, in rapidly changing radio conditions, such as in FR2 or particularly HST FR2 scenarios, conventional UE measurements, reports, and spatial relationship / UL or joint TCI status / UL beam switching indications generated by processes performed by the network (e.g., the radio access node 202 of the RAN 108) may be too slow to allow continuity. For example, the UE may have observed degradation in channel conditions on one of the TRP-specific links, or internally compared two TRP links, and selected a preferred one for UL transmission, but it may still take a considerable amount of time before the network provides an indication to change the UL link from TRP2 to TRP1.

[0054] Thereafter, if a beam failure occurs, there is no guarantee that a recovery beam will be found in the set of BFD / BFR resources that would normally be provided to the UE 110 for TRP2 302B that experienced the failure. On the other hand, TRP1 302A may still have a reliable connection and may be used for both UL and DL before a new TRP is identified for recovery. Furthermore, if beam recovery assumes SR transmission in the LRR resources provided to the UE (without the RA preamble), there is no guarantee that the network or TRP1 will be able to receive the SR, as the UE's UL transmit timing may not be adjusted for TRP1. This situation may delay link / beam recovery associated with the three possible failure modes.

[0055] In a failure scenario, both TRP1 302A and TRP2 302B may fail. In this failure scenario, current requirements specify that UE 110 trigger beam failure recovery by initiating a RA procedure on the cell. The UE may obtain the UL Transmit Timing Adjustment (TA) value in the Random Access Response (RAR).

[0056] A second failure scenario may include a failure on TRP1 302A. In the event of a failure, two problems may arise. If the UE 110 is configured with LRR according to TRP1 and TRP2 302B, and a new beam is discovered in TRP1, the UE may attempt to send an SR to TRP1 (for BFR MAC CE transmission), but the UL transmit timing corresponds to TRP2 (where the UL is currently configured). If the propagation delay difference between TRP1 and TRP2 is higher than the length of the guard period (e.g., cyclic prefix CP) between data units (symbols) sent by the TRPs, TRP1 may not be able to receive the transmission. A second possible problem is that the UE may not be able to find or recover the new beam on TRP1. In this case, the UE may not be able to send an SR and a BFR MAC CE to TRP1; and therefore, the network may not have beam failure information on the TRP1 link until the BFR ends.

[0057] The third failure scenario is related to a failure on TRP2 302B. In this case, the UL connection towards TRP2 is disconnected along with the DL. If another beam is found at TRP2, recovery can proceed according to existing procedures. However, if the link to TRP2 can no longer be used, the UE 110 may need to do a full BFR to the new TRP. During beam recovery, the UL may be interrupted, while the link to TRP1 302A may remain reliable enough and can also be used for the UL. Another potential problem may be that the UL transmit timing towards TRP1 and TRP2 is very different. If the UE 110 transmits to TRP1 with the same UL transmit timing advance (TA) as TRP2, TRP1 may not receive the transmission when TRP1 actually has different timing.

[0058] In view of the above failure scenarios, it can be understood that the UE 110 is currently unable to indicate the need to switch the UL with TRP2 302B to TRP1 302A or another serving TRP before a beam failure may occur. In addition, after a beam failure occurs, due to potential differences in UL transmit timing, it cannot always be ensured that the SR of a subsequent BFR MAC CE transmission can be delivered to the new TRP. The example implementations of the present disclosure address these and possible other issues. In some examples, the first problem can be solved by enabling the UE to identify situations where a beam failure may occur and preemptively switch TRPs. In some examples, the second problem can be solved by the UE autonomously adjusting the UL transmit timing to ensure that if a beam failure does occur, the correct timing can be used to achieve UL transmission towards the second (non-faulty) TRP.

[0059] Before describing the above potential countermeasures in more detail, it is worth noting that the example implementations of the present disclosure are not limited to the specific HST FR2 scenario of simultaneous dual-panel reception. However, the example implementations may be particularly suitable for addressing situations such as the tunnel scenario described above, where beam failure may occur due to a sharp drop in the beamforming signal next to the TRP.

[0060] Figure 4 A deployment scenario 400 is illustrated in which an HST FR2 UE 402 is expected to experience the beam failure condition described in the third failure condition above. The UE has two antenna panels facing opposite directions on an HST moving in the direction indicated by arrow 404. The two antenna panels are generating a first beam 406A and a second beam 406B. Figure 4 At the time shown, the first beam is directed to the first TRP 408A (TRP1) and the beam 410 generated by TRP1. At the same time, the second beam is directed to the second TRP 408B (TRP2) and the beam 412 generated by TRP2. Since the UE is much closer to TRP2 than to TRP1, the signal strength from TRP2 can be higher, and the UE expects to use the link to / from TRP2 for both DL and UL. At the same time, the UE can relatively quickly pass to the point where the fourth TRP 408D (TRP 4) is expected to be the best connection source.

[0061] As the HST advances to a point where the UE 402 is placed at the potential failure point 414, the beam coverage from the TRP 408B may be dramatically reduced. Figure 5 A graph 500 is shown showing the relationship between reference signal received power (RSRP) and distance along the HST track. Line 502 shows the relationship between RSRP and distance along the HST track. Figure 4 At the potential failure point, the RSRP from TRP2 is higher than the RSRP of TRP4 408D shown in line 504. The RSRP of TRP4 at line 504 remains relatively stable and is actually much higher than the RSRP of line 502 after the potential failure point. This change is very drastic and may happen so quickly that the UE may not have enough time to switch the DL (and UL) link from TRP2 (the source TRP) to TRP4 (the best target TRP).

[0062] In previous versions associated with multiple TRP scenarios, and in scenarios where high mobility situations are not considered, it is assumed by default that there is no significant propagation delay difference (i.e., the delay difference is less than the CP length) between TRP1 408A, TRP2 408B, and TRP4 408D. Therefore, example implementations of the present disclosure are intended to provide support for situations where the propagation delay difference (such as the maximum receive timing difference (MRTD)) is greater than the length of the CP or other protection period.

[0063] Back to Figure 3 , some example implementations may provide a method for preventing UL outages due to UL failures as well as DL failures toward TRP2302B. To achieve this, UE 110 may be provided with the ability to identify TRP link degradation, where the UL is used more dynamically, for example, before any actual beam failure occurs. Thus, the UE may signal the network of degradation of the TRP link by providing a TRP link degradation indication. In various examples, the indication may be provided by a dedicated signal, or extend / adopt another signal, such as a UL SR, measurement report, etc., to include information indicating the degradation.

[0064] In some examples, UE 110 may be configured (or otherwise include a component configured) to compare link qualities on TRP1 302A and TRP2 302B, and provide a timely indication to the network (e.g., radio access node 202) regarding the need to switch the UL from TRP2 to TRP1. As described above, the indication may be provided to the network by modifying an existing signal (such as an SR or measurement report) or by a dedicated signal (generally referred to as providing UE assistance information (associated with indicating link degradation)). Based on the link degradation indication, the network may accept the switch of the UL (e.g., UL spatial relationship or UL TCI state) more quickly and may send a confirmation, for example, in a DCI message, rather than via MAC CE or RRC signaling.

[0065] In some cases, this approach may be slightly modified. For example, in some scenarios (e.g., in HST FR2 tunnels), when certain UE conditions occur based on experience, the network (e.g., radio access node 108, CN 106) may have information about potential link failures. The information that the network can use for this purpose may include various parameters related to the mobility of UE 110, such as the direction and / or speed of movement, receiver configuration, etc. Therefore, the network can avoid using one of the TRP links that is more prone to BF for the UL, or exclude switching to a link that the UE reports as better based on having a higher RSRP value.

[0066] As described above, some example implementations may effectively prevent UL interruptions. Some example implementations may also facilitate recovery from beam failures. In some examples, where the UE 110 is connected to TRP1 302A and TRP2 302B in the DL, and only one of these links / beams fails, it may be beneficial for the UE 110 to start using another link in the UL as quickly as possible. Since the UE is already using a non-faulty link in the DL and the non-faulty link may be stable, the UE may not need to wait for the BFR on the faulty TRP to complete, during which the UL connection may be interrupted. Using such a sufficiently reliable non-faulty link may allow the UE to maintain connection with the serving cell in both the UL and DL. This may also provide more time for the UE and the network to perform measurements and find a good new beam for the same or another TRP so as to start serving the UE again from multiple TRPs.

[0067] As described above, some example implementations may respond effectively to beam failures, and may be implemented by providing the UE 110 with a new capability to autonomously adjust UL transmit timing in the event of a beam failure to enable UL transmissions to TRP1 302A. The UE may also decide between various options after a beam failure. These options may include checking whether autonomous UL timing adjustment is required and performing a SR and subsequent BFR MAC CE on a non-faulty link / beam, switching to another link by issuing a RA preamble, or initiating link recovery to a new TRP. For example, this may occur when no new candidate beams are available for TRP2 302B and switching the UL to TRP1 302A is not preferred. In this case, the UE may indicate a UL switch from TRP2 to TRP1 using a BFR MAC CE (or a new MAC CE) even before a new recovery beam for TRP2 or another TRP is identified. In one option, in case of beam failure, the UE may indicate the need for UL beam switching from TRP2 to TRP1 by issuing a SR on the LRR, i.e. without a subsequent BFR MAC CE.

[0068] Some example implementations may also handle failures on links not used for UL (i.e., on TRP1 302A). Following conventional practice, if LRR is configured, the UE 110 should issue a UL SR to TRP1 to indicate a new beam. However, this operation may not be successful if the UL transmit timing difference toward TRP1 is very different (e.g., higher than the CP) from the transmit timing difference of TRP2 302B on which the UL is currently configured. As a solution, the UE may be provided with the ability to indicate BF on one TRP to another TRP via UL, rather than issuing a UL SR and BFR MAC to TRP1. The UE may also evaluate the extent to which the propagation delays between TRP1 and TRP2 are different. If the UL transmit timing between TRP1 and TRP2 is very different (e.g., higher than a threshold difference), the UE may notify the network and receive a new candidate beam on TRP1 via the PUCCH on TRP2. The network either switches the DL beam on TRP1 to the beam indicated by the UE in the BFR MAC CE, or just confirms the beam switch (e.g., via DCI from TRP2).

[0069] Thus, some example implementations of the present disclosure may provide a UE 110 connected to both TRP1 302A and TRP2 302B. The UE has a first DL connection and a second DL connection with TRP1 and TRP2, respectively, but has only a UL connection with TRP2. The UE 110 may signal the network (via TRP2) UE capabilities (the UE capabilities including the ability to switch between TRPs), and RRC control signaling from the network to implement the capabilities at the UE.

[0070] UE 110 may be configured to monitor a radio link quality of a second DL connection with TRP2 302B, and identify a condition for switching the UL connection based at least on the radio link quality of the second DL connection. In some examples, the condition may be degradation of the second DL connection, which may be identified by comparison with the first DL connection. In this regard, the UE may monitor the first radio link quality of TRP1 302A and the second radio link quality of TRP2, and identify degradation of the second DL connection based on (comparison of) the first radio link quality and the second radio link quality. In some examples, the condition may be a condition of either or both of a UL control channel (PUCCH) or a UL shared channel (PUSCH) for switching the UL connection.

[0071] UE 110 may be configured to switch the UL connection from TRP2 302B to TRP1 302A based on the determination. Specifically, for example, the UE may signal the network (TRP2 302B) to request switching the UL connection to TRP1.

[0072] Figure 6 is a signaling diagram 600 for preventing UL interruption according to some example implementations. In this regard, Figure 6 A scenario is shown when UE 110 indicates a need to switch from TRP2 302B to TRP1 302A. In this example, the UE may have more, more dynamic, and up-to-date information about the status of the links toward TRP1 and TRP2 than the network. Even if a beam failure occurs on TRP2 later, the UE's UL connection is not interrupted. In addition, the UL switch between the two links already used for DL ​​may be arranged with less latency and less signaling overhead. For example, a more dynamic DCI signaling may be used to confirm the change of UL from TRP2 to TRP1.

[0073] refer to Figure 6 , steps 601-614 are shown and described. Notably, step 601 includes an example of an existing message from UE 110 to TRP2 302B for indicating UE capabilities. However, the existing message is further modified to include a switching indication (e.g., an inter-TRP switching indication for UL) through the example implementation as described above. Step 602 also adds an indication from the network (via TRP2) to the existing RRC signaling message to implement inter-TRP switching for UL when necessary. Steps 603, 604, 605, 606, and 607 describe UE measurements based on SSB / CSI-RS sent from the TRP, as well as data exchange on PDSCH / PUSCH and control information exchange on PUCCH / PDCCH, and may be as currently specified by various 3GPP standards. At step 608, the UE identifies the need to switch the UL from TRP2 to TRP1 302A. The switching request at step 609 may use dedicated signaling or modifications to existing signaling (e.g., SR, measurement report). The network's indication of UL switching at step 610 may also be implemented using existing signaling (e.g., spatial relationship switching MAC CE) or using new signaling (e.g., DCI confirmation of inter-TCI UL switching). Steps 611, 612, 613, and 614 may continue the process of switching UL from TRP2 to TRP1.

[0074] Some other example implementations described above provide a network node, such as a radio access node 202, or other network node or RAN 108 or CN 106. In some of these other example implementations, the network node may be configured to collect operational information, which includes information related to one or more of TRP1 302A, TRP2 302B, or UE 110. The operational information may additionally or alternatively include, for example, information related to other neighboring TRPs or cells. The network node may be configured to perform an evaluation of the operational information of a potential UL failure at TRP1 or TRP2, and make a determination based on the evaluation whether to switch the UL connection from TRP2 to TRP1. As described above, in some examples, the operational information includes one or more of the following: beam failure information of at least one of TRP1 302A or TRP2 302B. The operational information may also include the signal strength of at least one of TRP1 or TRP2, the location of UE 110, the speed of the UE, the direction of travel of the UE, or interference in the environment of at least one of TRP1, TRP2, or UE.

[0075] In some examples, when the evaluation indicates a potential UL failure at TRP1 302A, the network node can make a determination not to switch the UL connection. In some other examples, when the evaluation indicates a potential UL failure at TRP2 302B, the network node can make a determination to switch the UL connection. In some of these examples, the network node 202 is further configured to switch the UL connection from TRP2 to TRP1 based on the determination.

[0076] To further illustrate some of the above example implementations, Figure 7 is a signaling diagram for using experience-based information from the network side to predict a potential need for UL switching to prevent UL interruption according to some example implementations. Figure 6 , Figure 7 The signaling in the UE 302A is more focused on the network side. In step 701, the network collects additional information that enables a decision to be made on the need for UL switching between TRP1 302A and TRP2 302B. In one example, the network can collect statistics of BFs in the area in combination with other additional information (e.g., signal strength of TRP, UE location, speed, interference, etc.).

[0077] Steps 702, 703, and 704 represent typical signaling where the DL of the UE 110 is connected to both TRP1 302A and TRP2 302B, but the UL is only connected to TRP1. Repeated execution of routine signaling between TRP1 and TRP2 is shown at 705, which includes steps 706 and 707, and a measurement report is provided by the UE to the network via TRP1 at step 708. If, at step 709, TRP2 appears to offer better connection potential than TRP1, then at step 710, based on the collected data, the network can predict the likelihood of BF. In response, the network can also instruct to keep the UL at TRP1 even if the link quality to TRP2 becomes better than the link quality to TRP1 if the network has a higher probability of BF in TRP2 than in TRP1.

[0078] In some examples, such as Figure 4 In an HST FR2 tunnel deployment in step 701, the network may collect information about the UE's direction of movement, such as what the UE's previous TRP was or what the sign of the frequency offset was. This experience-based information may enable the network to conclude in step 710 whether the UE is heading towards TRP1 302A or TRP2 302B. In this example, if TRP2 is determined to be more prone to BF, the network may decide to keep the UL at TRP1 even if the signal strength from TRP2 is found to be better at step 709. In step 710, the network may also obtain additional information about the UE and / or network configuration. For example, if discontinuous reception (DRX) is implemented and the TRP is located in a tunnel, TRP2 may be avoided for the UL.

[0079] Briefly return to Figure 3 In yet another example implementation, the UE 110 may be configured to detect a beam failure of a second DL connection with TRP2 302B. The UE may perform an evaluation of the UL condition of TRP1 and make a determination to switch the UL connection from TRP2 to TRP1 302A or a third TRP based on the evaluation. The UE may then be configured to switch the UL connection from TRP2 to TRP1 or a third TRP based on the determination, such as by signaling to the network to request a switch of the UL.

[0080] In some examples, where a determination is made to switch the UL connection from TRP2 302B to TRP1 302A, the UE 110 may make a second determination whether the UE is able to determine a timing adjustment for TRP1 302A, and switch the UL connection from TRP2 to TRP1 based on the second determination. If the second determination is that the UE is able to determine the timing adjustment, the UE may determine the timing adjustment; and using the timing adjustment, the UE may signal the network via TRP1 to request switching the UL connection to TRP1. If the second determination is that the UE is unable to determine the timing adjustment, the UE may signal the network via a random access channel of TRP1 to obtain the timing adjustment; and using the timing adjustment, the UE may signal the network to request switching the UL connection to TRP1.

[0081] In some examples, where a determination is made to switch the UL connection from TRP2 302B to a third TRP, the UE 110 may signal the network via a preamble transmission to the third TRP to obtain a timing adjustment for the third TRP. And using the timing adjustment, the UE may signal the network via the third TRP to request switching the UL connection to the third TRP.

[0082] Fig. 8A and Figure 8B 8 is a signaling diagram for responding to beam failure by autonomously adjusting UL transmit timing according to some example implementations. As shown in steps 801, 802, 803 and 804, UE 110 can signal the network via TRP2 302B UE capabilities, which include the ability to autonomously adjust UL timing TRP1 302A and TRP2 in the case of BF, and the network can implement the capability. The network can also signal the UE BFD / BFR configuration, such as periodic reference signal resources ( and ), two configurations for PUCCH transmission with LRR, used for TRP1 and TRP2 (schedulingRequestID-BFR), etc.

[0083] Steps 805-810 describe sending out reference signals and sending out UL and DL data / control information, similar to steps 603-607, and may be as currently specified by various 3GPP standards.

[0084] At step 811, the UE may detect beam failure on the UL connection in conjunction with TRP2 302B; and at step 812, the UE may evaluate the UL conditions of TRP1, such as the conditions of the PUCCH on TRP1, and based on the evaluation, make a determination to switch the UL connection from TRP2 to TRP1 302A or a third TRP (TRPx).

[0085] As a first option at 813, the UE 110 determines that the UE is able to transmit to TRP1 302A in the UL. This is possible, for example, if the propagation delay difference between TRP1 and TRP2 302B is less than a threshold difference (e.g., less than the length of the CP), or if the UE can reliably estimate the timing difference between TRP1 302A and TRP2 302B. At step 814, the UE evaluates whether an UL transmit timing adjustment is required, and performs an UL transmit timing adjustment if required.

[0086] At steps 815, 816 and 817, the UE issues a UL SR and BFR MAC CE to the network via TRP1, and receives DCI to schedule PUSCH. Through this signaling, the UE can inform the network of the beam failure on TRP2 and request to switch the UL to TRP1. The signaling towards TRP1 indicates that the UL should be switched from TRP2 to TRP1 even if the UE has not indicated a new beam for recovery (in the BFR MAC CE, the AC field can be 0). Note that by default, the UE may not use the TRP1 beam for recovery because the DL beam for TRP1 has not failed yet. At step 818, the network switches the UL from TRP2 to TRP1 via TRP2.

[0087] As also shown, steps 819 - 824 may be as currently specified by various 3GPP standards.

[0088] As Figure 8B In the second option at 813 shown, the UE 110 determines that the UE cannot transmit to TRP1 302A in the UL. That is, the UE concludes that the UE cannot perform a single / autonomous timing adjustment to transmit to TRP1, which may be because the DL synchronization with TRP2 has been lost or outdated. In this case, even if the LLR resources are configured, the network may not expect to obtain an SR via TRP1. Therefore, the UE may initiate a RA preamble transmission to TRP1 at step 826 and receive a new timing adjustment value and an UL grant for a BFR MAC CE at step 827. The UE may then issue a BFR MAC CE to the network (via TRP1) at step 828, which the network may interpret as a need to switch the UL to TRP1 instead of the final BFR. At step 829, the network switches the UL from TRP2 to TRP1 via TRP2.

[0089] As also shown, at steps 830-834, the DL from TRP1 may be switched to a third TRPx.

[0090] In a third option, at 835 and through steps 836-842, the UE may decide to recover from the beam failure and then directly recover to the third TRPx. This may occur, for example, if no candidate beams are detected for TRP2 302B and implementing UL on TRP1 302A has similar overhead (e.g., autonomous UL timing adjustment cannot be performed and RACH is also required).

[0091] Return again Figure 3 In yet another example implementation, UE 110 may be configured to detect a beam failure of a first DL connection with TRP1 302A. In some of these examples, the UE is configured to evaluate a propagation delay difference between TRP1 and TRP2. The UE may make a determination based on the propagation delay difference whether to perform a beam recovery procedure to recover the first DL connection using TRP1 or through a UL connection with TRP2. The UE may then perform a beam recovery procedure based on the determination.

[0092] In particular, for example, the UE may make this determination based on a propagation delay difference and a threshold difference, such as the length of a guard period (e.g., CP) between data units sent by TRP1 302A and TRP2 302B. If the propagation delay difference is less than (or not greater than) the threshold difference, the UE may determine to perform a beam recovery procedure using TRP1 302A. The beam recovery procedure may be the same or similar to that specified in the 3GPP specification.

[0093] If the propagation delay difference is greater than the threshold difference, the beam recovery procedure may be performed instead via the UL connection with TRP2 302B. In this regard, the UE 110 may signal the network (via the UL connection with TRP2) to indicate a candidate DL beam of TRP1 302A for recovery of the first DL connection. The UE may then receive a message from the network indicating that the UE switched to the candidate DL beam, or confirming the switch to the candidate DL beam.

[0094] Fig. 9 302B to resume a first DL connection with TRP1 302A using a UL connection with TRP2 302B according to some example implementations. As shown in steps 901 and 902, UE 110 may signal UE capabilities to the network via TRP2 302B, including an indication of BF over another TRP, and the network may provide RRC signaling to implement the capabilities. The network may also signal BFD and BFR resources for TRP1 and TRP2, and LLRs are configured for both TRP1 and TRP2.

[0095] Steps 903-907 describe sending out reference signals and sending out UL and DL data / control information, and may be as specified by various current 3GPP standards.

[0096] At steps 908 and 909, the UE 110 indicates BF on TRP1 302A and restores the beam on TRP1. At step 910, the UE evaluates the propagation delay difference between TRP1 and TRP2 302B. As a first option, at 911, the UE determines that the time difference is within the CP, and at step 912, the UE performs a conventional BFR procedure using TRP1. The beam restoration procedure may be the same or similar to that specified in the 3GPP specification.

[0097] As a second option, at 913, the UE determines that the time difference is greater than the CP, and the UE performs a BFR procedure using the UL connection with TRP2 302B. The UE issues a candidate beam for TRP1 to the network via the UL connection with TRP2 (such as by PUSH in the BFR MAC CE) at step 914. At step 915, TRP2 notifies TRP1 of the beam indicated by the UE. At step 916, the network issues a beam switching command for TR1 via TRP2 or a confirmation of the UE-indicated recovery beam. In this regard, a beam switching command (such as a TCI state switching command) may specifically indicate that the beam is switched for TRP1 302A, even if the command comes from TRP2. Alternatively, the network may issue a confirmation of the switch to the beam (indicated by the UE in the BFR MAC CE at TRP1), such as in a new DCI message.

[0098] Fig. 10A and Fig. 10B 1 is a flow chart illustrating various steps in method 1000 according to various example implementations. Fig. 10A As shown in box 1002, the method includes monitoring the radio link quality at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of the network. The user equipment has a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but has an uplink (UL) connection with the second TRP and does not have a UL connection with the first TRP; and the monitored radio link quality is the radio link quality of the second DL connection with the second TRP. As shown in box 1004, the method includes identifying a condition for switching the UL connection based on at least the radio link quality of the second DL connection. And as shown in box 1006, the method includes switching the UL connection from the second TRP to the first TRP based on the determination.

[0099] In some examples, such as Fig. 10BAs shown in block 1008 of , method 1000 also includes signaling, from the user equipment via the second TRP, to the network the user equipment capabilities, the user equipment capabilities including the ability to switch between TRPs. In some of these examples, as shown in block 1010, the method also includes receiving, at the user equipment, radio resource control signaling from the network via the second TRP to implement the capabilities at the user equipment.

[0100] In some examples, monitoring the radio link quality at block 1002 includes monitoring a first radio link quality of the first TRP and a second radio link quality of the second TRP. In some of these examples, the condition is degradation of the second DL connection, and the condition is identified at block 1004 based on the first radio link quality and the second radio link quality.

[0101] In some examples, the condition identified at block 1004 is a condition for switching at least one of a UL control channel or a UL shared channel of the UL connection. In some of these examples, switching the UL connection at block 1006 includes switching at least one of the UL control channel or the UL shared channel.

[0102] In some examples, switching the UL connection at block 1006 includes signaling from the user equipment to the network via the second TRP to request switching the UL connection to the first TRP.

[0103] Fig.11A and Fig. 11B 1 is a flow chart illustrating various steps in method 1100 according to various example implementations. Fig.11A As shown in box 1102, the method includes: collecting operational information at a network including a first transmission reception point (TRP) and a second TRP. The operational information is related to one or more of the first TRP, the second TRP, or a user equipment connected to both the first TRP and the second TRP. The user equipment has a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but has an uplink (UL) connection with the second TRP and does not have a UL connection with the first TRP. As shown in box 1104, the method includes performing an evaluation of the operational information of a potential UL failure at either the first TRP or the second TRP. And as shown in box 1106, the method includes making a determination at the network based on the evaluation whether to switch the UL connection from the second TRP to the first TRP.

[0104] In some examples, the operational information includes beam failure information for at least one of the first TRP or the second TRP.

[0105] In some examples, the operational information also includes one or more of: signal strength of at least one of the first TRP or the second TRP, the location of the user device, the speed of the user device, the direction of travel of the user device, or interference in the environment of at least one of the first TRP, the second TRP, or the user device.

[0106] In some examples, a determination is made at block 1106 not to switch the UL connection when the evaluation indicates a potential UL failure at the first TRP.

[0107] In some examples, when the evaluation indicates a potential UL failure at the second TRP, a determination is made at block 1106 to switch the UL connection. In some of these examples, such as Fig. 11B As shown in box 1108, method 1100 also includes switching the UL connection from the second TRP to the first TRP based on the determination.

[0108] Figure 12A-12E 1 is a flow chart illustrating various steps in method 1200 according to various example implementations. Fig. 12A As shown in box 1202. The method includes detecting a beam failure at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network. The user equipment has a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but has a UL connection with the second TRP and does not have a UL connection with the first TRP; and the beam failure is a beam failure of the second DL connection with the second TRP. As shown in box 1204, the method includes performing an evaluation of the UL condition of the first TRP. As shown in box 1206, the method includes making a determination to switch the UL connection from the second TRP to the first TRP or the third TRP based on the evaluation. And as shown in box 1208, the method includes switching the UL connection from the second TRP to the first TRP or the third TRP based on the determination.

[0109] In some examples, when a determination is made at block 1206 to switch the UL connection from the second TRP to the first TRP, as Fig. 12B As shown in block 1210 of , the method further includes making a second determination whether the user equipment is able to determine the timing adjustment of the first TRP. In some of these examples, as shown in block 1212, switching the UL connection at block 1208 includes switching the UL connection from the second TRP to the first TRP based on the second determination.

[0110] In some examples, when the user equipment is able to determine a second determination of a timing adjustment for the first TRP is made at block 1210, such as Fig. 12CAs shown in block 1214 of the method, the method also includes determining a timing adjustment for the first TRP. And using the timing adjustment, as shown in block 1216, switching the UL connection from the second TRP to the first TRP at block 1212 includes signaling from the user equipment via the first TRP to the network to request switching the UL connection to the first TRP.

[0111] In some examples, when the user equipment is unable to determine a second determination of a timing adjustment is made at block 1210, such as Fig.12D As shown in block 1218 of the method, at block 1212, switching the UL connection from the second TRP to the first TRP includes signaling from the user equipment to the network via a preamble transmission to the first TRP to obtain a timing adjustment. And using the timing adjustment, as shown in block 1220, the method includes signaling from the user equipment to the network via the first TRP to request switching the UL connection to the first TRP.

[0112] In some examples, when a determination is made at block 1206 to switch the UL connection from the second TRP to the third TRP, Fig.12E As shown in block 1222 of the method, the method further includes signaling from the user equipment to the network via a preamble transmission to the third TRP to obtain a timing adjustment for the third TRP. And using the timing adjustment, as shown in block 1224, the method includes signaling from the user equipment to the network via the third TRP to request a switch of the UL connection to the third TRP.

[0113] Fig.13A and Fig. 13B 1 is a flow chart illustrating various steps in method 1300 according to various example implementations. Fig.13A As shown in box 1110 of , the method includes detecting a beam failure at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network. The user equipment has a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but has an UL connection with the second TRP and does not have an UL connection with the first TRP; and the beam failure is a beam failure of the first DL connection with the first TRP. As shown in box 1302, the method includes evaluating a propagation delay difference between the first TRP and the second TRP. As shown in box 1306, the method includes making a determination based on the propagation delay difference whether to utilize the first TRP or to perform a beam recovery process to recover the first DL connection through a UL connection with the second TRP. And as shown in box 1308, the method includes performing a beam recovery process based on the determination.

[0114] In some examples, the determination is made at block 1306 based on a propagation delay difference and a threshold difference, and the threshold difference is the length of a guard period between data units sent by the first TRP and the second TRP.

[0115] In some examples, when the propagation delay difference is less than a threshold difference, a determination is made at box 1306 to perform a beam recovery process using the first TRP.

[0116] In some examples, when the propagation delay difference is greater than a threshold difference, a determination is made at box 1306 to perform a beam recovery process via a UL connection with a second TRP.

[0117] Further in some examples, such as Fig. 13B As shown in block 1310 of the embodiment, performing the beam recovery process at block 1308 via the UL connection with the second TRP includes signaling from the user equipment to the network via the UL connection with the second TRP to indicate a candidate DL beam of the first TRP for recovering the first DL connection. In some of these examples, as shown in block 1312, the method includes receiving a message at the user equipment from the network via the UL connection with the second TRP to indicate that the user equipment switched to the candidate DL beam, or confirming the switch to the candidate DL beam.

[0118] According to example implementations of the present disclosure, telecommunication system 100 or PLMN 102 and components thereof (such as CN 106, RAN 108, UE 110, UE 402, radio access node 202, first TRP 302A and / or second TRP 302B) may be implemented in various ways. Components for implementing the system and its components may include hardware, alone or under the guidance of one or more computer programs from a computer-readable storage medium (such as a computer memory (or more simply referred to as "memory"). In some examples, one or more devices may be configured to act as or otherwise implement the systems and components thereof shown and described herein. In examples involving more than one device, the respective devices may be connected to each other or otherwise communicate with each other in a variety of different ways, such as directly or indirectly via a wired or wireless network, etc.

[0119] Fig.14An apparatus 1400 according to some example implementations of the present disclosure is illustrated. In general, an apparatus of an exemplary implementation of the present disclosure may comprise, include, or be embodied in one or more fixed or portable electronic devices. Examples of suitable electronic devices include wearable computers, mobile phones, portable computers, desktop computers, workstation computers, servers (server computers), etc. The apparatus may include one or more of each of a plurality of components, such as, for example, a processing circuit system 1402 connected to a computer-readable storage medium 1404.

[0120] Processing circuitry 1402 may be comprised of one or more processors, alone or in combination with one or more computer-readable storage media. Processing circuitry is generally any computer hardware capable of processing information (such as, for example, data, computer programs, and / or other suitable electronic information). Processing circuitry is comprised of a set of electronic circuits, some of which may be packaged as an integrated circuit or multiple interconnected integrated circuits (integrated circuits are sometimes more commonly referred to as "chips"). Processing circuitry may be configured to execute a computer program, which may be stored on the processing circuitry or otherwise stored in a computer-readable storage medium 1404 (of the same or another device).

[0121] Depending on the specific implementation, the processing circuit system 1402 can be a plurality of processors, a multi-core processor, or some other type of processor. In addition, the processing circuit system can be implemented using a plurality of heterogeneous processor systems, in which a main processor and one or more auxiliary processors are present on a single chip. As another illustrative example, the processing circuit system can be a symmetric multi-processor system containing multiple processors of the same type. In yet another example, the processing circuit system can be embodied as or otherwise include one or more ASICs, FPGAs, etc. Therefore, although the processing circuit system is capable of executing a computer program to perform one or more functions, the processing circuit systems of various examples are capable of performing one or more functions without the help of a computer program. In either case, the processing circuit system can be appropriately programmed to perform functions or operations implemented according to the examples of the present disclosure.

[0122] Computer-readable storage media 1404 is generally any computer hardware capable of temporarily and / or permanently storing information, such as, for example, data, computer programs (e.g., computer-readable program code 1406), and / or other suitable information. Computer-readable storage media may include volatile and / or non-volatile memory, and may be fixed or removable. Examples of suitable memory include random access memory (RAM), read-only memory (ROM), hard drive, flash memory, thumb drive, removable computer disk, optical disk, or some combination thereof. Computer-readable storage media are non-transient devices capable of storing information, and are different from computer-readable transmission media (such as electronic transient signals) that can carry information from one location to another. The term "non-transient" as used herein is a limitation on the medium itself (i.e., tangible, rather than a signal), rather than a limitation on the persistence of data storage (e.g., RAM vs. ROM). Computer-readable media as described herein may generally refer to computer-readable storage media or computer-readable transmission media.

[0123] In addition to computer-readable storage media 1404, processing circuit system 1402 may also be connected to one or more interfaces for displaying, sending and / or receiving information. The interface may include a communication interface 1408 and / or one or more user interfaces. The communication interface may be configured to send information to (multiple) other devices, (multiple) networks, etc. and / or receive information therefrom. The communication interface may be configured to send and / or receive information via a physical (wired) and / or wireless communication link. Examples of suitable communication interfaces include a network interface controller (NIC), a wireless NIC (WNIC), etc.

[0124] The user interface may include a display 1410 and / or one or more user input interfaces 1412. The display may be configured to present or otherwise display information to a user, suitable examples of which include a liquid crystal display (LCD), a light emitting diode (LED) display, an organic LED (OLED) display, an active matrix OLED (AMOLED), etc. The user input interface may be wired or wireless, and may be configured to receive information from a user into the device, such as for processing, storage, and / or display. Suitable examples of user input interfaces include a microphone, an image or video capture device, a keyboard or keypad, a joystick, a touch-sensitive surface (separate from or integrated into a touch screen), a biometric sensor, etc. The user interface may also include one or more interfaces for communicating with peripheral devices (such as a printer, a scanner, etc.).

[0125] As described above, program code instructions can be stored in a computer-readable storage medium and executed by the processing circuit system programmed thereby to implement the functions of the systems, subsystems, tools and their corresponding elements described herein. As will be appreciated, any suitable program code instructions can be loaded from a computer-readable storage medium onto a computer or other programmable device to produce a specific machine so that the specific machine becomes a component for implementing the functions described herein. These program code instructions can also be stored in a computer-readable storage medium, which can instruct a computer, a processing circuit system or other programmable device to operate in a particular manner, thereby generating a specific machine or a specific product. Instructions stored in a computer-readable storage medium can produce products, wherein the products become means for implementing the functions described herein. Program code instructions can be retrieved from a computer-readable storage medium and loaded into a computer, a processing circuit system or other programmable device to configure a computer, a processing circuit system or other programmable device to perform operations performed on or by a computer, a processing circuit system or other programmable device.

[0126] The retrieval, loading, and execution of program code instructions may be performed sequentially, such that one instruction is retrieved, loaded, and executed at a time. In some example implementations, the retrieval, loading, and / or execution may be performed in parallel, such that multiple instructions may be retrieved, loaded, or executed together. The execution of program code instructions may produce a computer-implemented process such that the instructions executed by a computer, processing circuitry, or other programmable device provide operations for implementing the functions described herein.

[0127] The execution of the instructions by the processing circuit system, or the storage of the instructions in the computer-readable storage medium, supports a combination of operations for performing the specified functions. In this manner, the apparatus 1400 may include a processing circuit system 1402 and a computer-readable storage medium 1404 coupled to the processing circuit system, wherein the processing circuit system is configured to execute a computer-readable program code 1406 stored in the computer-readable storage medium. It will also be understood that one or more functions and combinations of functions may be implemented by a dedicated hardware-based computer system and / or processing circuit system that performs the specified functions, or by a combination of dedicated hardware and program code instructions.

[0128] As stated above and reiterated below, the present disclosure includes, but is not limited to, the following example implementations, and those presented hereafter in the appended claims.

[0129] Clause 1. A device comprising: at least one memory configured to store computer-readable program code; and at least one processing circuit system configured to access the at least one memory and execute the computer-readable program code so that the device at least: monitors the radio link quality at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection respectively with the first TRP and the second TRP, but having an uplink (UL) connection with the second TRP and not having a UL connection with the first TRP, the monitored radio link quality being the radio link quality of the second DL connection with the second TRP; identifies conditions for switching the UL connection based at least on the radio link quality of the second DL connection; and switches the UL connection from the second TRP to the first TRP based on the determination.

[0130] Clause 2. An apparatus according to clause 1, wherein the at least one processing circuit system is configured to execute the computer-readable program code so that the apparatus further at least: signals the network via the second TRP from the user equipment to notify the user equipment of user equipment capabilities, wherein the user equipment capabilities include the ability to switch between TRPs; and receives radio resource control signaling from the network via the second TRP at the user equipment to implement the capabilities at the user equipment.

[0131] Clause 3. An apparatus according to clause 1 or 2, wherein the apparatus configured to monitor the radio link quality comprises the apparatus configured to monitor a first radio link quality of the first TRP and a second radio link quality of the second TRP, and wherein the condition is degradation of the second DL connection, and the condition is identified based on the first radio link quality and the second radio link quality.

[0132] Clause 4. An apparatus according to any one of clauses 1 to 3, wherein the identified condition is a condition for switching at least one of a UL control channel or a UL shared channel of the UL connection, and the apparatus caused to switch the UL connection includes the apparatus caused to switch at least one of the UL control channel or the UL shared channel.

[0133] Clause 5. An apparatus according to any one of clauses 1 to 4, wherein the apparatus that is caused to switch the UL connection includes the apparatus that is caused to signal the network from the user equipment via the second TRP to request switching the UL connection to the first TRP.

[0134] Clause 6. A device comprising: a component for monitoring the radio link quality at a user equipment connected to a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP respectively, but having an uplink (UL) connection with the second TRP and not having a UL connection with the first TRP, the monitored radio link quality being the radio link quality of the second DL connection with the second TRP; a component for identifying conditions for switching the UL connection based at least on the radio link quality of the second DL connection; and a component for switching the UL connection from the second TRP to the first TRP based on the determination.

[0135] Clause 7. An apparatus according to Clause 6, wherein the apparatus further comprises: a component for signaling user equipment capabilities from the user equipment to the network via the second TRP, the user equipment capabilities including the ability to switch between TRPs; and a component for receiving radio resource control signaling from the network at the user equipment via the second TRP to implement the capabilities at the user equipment.

[0136] Clause 8. An apparatus according to clause 6 or 7, wherein the component for monitoring includes monitoring a first radio link quality of the first TRP and a second radio link quality of the second TRP, and wherein the condition is degradation of the second DL connection, and the condition is identified based on the first radio link quality and the second radio link quality.

[0137] Clause 9. An apparatus according to any one of clauses 6 to 8, wherein the identified condition is a condition for switching at least one of a UL control channel or a UL shared channel of the UL connection, and the means for switching includes switching at least one of the UL control channel or the UL shared channel.

[0138] Clause 10. An apparatus according to any one of clauses 6 to 9, wherein the means for switching comprises signaling from the user equipment to the network via the second TRP to request switching of the UL connection to the first TRP.

[0139] Clause 11. A method comprising: monitoring the radio link quality at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP respectively, but having an uplink (UL) connection with the second TRP and not having a UL connection with the first TRP, the monitored radio link quality being the radio link quality of the second DL connection with the second TRP; identifying a condition for switching the UL connection based at least on the radio link quality of the second DL connection; and switching the UL connection from the second TRP to the first TRP based on the determination.

[0140] Clause 12. A method according to Clause 11, wherein the method further comprises: signaling user equipment capabilities from the user equipment to the network via the second TRP, wherein the user equipment capabilities include the ability to switch between TRPs; and receiving radio resource control signaling from the network at the user equipment via the second TRP to implement the capabilities at the user equipment.

[0141] Clause 13. A method according to clause 11 or 12, wherein monitoring the radio link quality includes monitoring a first radio link quality of the first TRP and a second radio link quality of the second TRP, and wherein the condition is degradation of the second DL connection, and the condition is identified based on the first radio link quality and the second radio link quality.

[0142] Clause 14. A method according to any one of clauses 11 to 13, wherein the identified condition is a condition for switching at least one of a UL control channel or a UL shared channel of the UL connection, and switching the UL connection includes switching at least one of the UL control channel or the UL shared channel.

[0143] Clause 15. A method according to any one of clauses 11 to 14, wherein switching the UL connection comprises signaling from the user equipment to the network via the second TRP to request switching the UL connection to the first TRP.

[0144] Clause 16. A non-transitory computer-readable storage medium having computer-readable program code stored therein, which, in response to execution of the computer-readable program code by at least one processing circuit system, causes the device to at least: monitor the radio link quality at a user equipment connected to a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection respectively with the first TRP and the second TRP, but having an uplink (UL) connection with the second TRP and not having a UL connection with the first TRP, the monitored radio link quality being the radio link quality of the second DL connection with the second TRP; identify conditions for switching the UL connection based at least on the radio link quality of the second DL connection; and switch the UL connection from the second TRP to the first TRP based on the determination.

[0145] Clause 17. A computer-readable storage medium according to Clause 16, wherein the computer-readable storage medium has additional computer-readable program code stored therein, and the additional computer-readable program code, in response to execution by the at least one processing circuit system, causes the device to at least: signal the user equipment capabilities to the network via the second TRP from the user equipment, wherein the user equipment capabilities include the ability to switch between TRPs; and receive radio resource control signaling from the network via the second TRP at the user equipment to implement the capabilities at the user equipment.

[0146] Clause 18. A computer-readable storage medium according to clause 16 or 17, wherein the device configured to monitor the radio link quality includes the device configured to monitor a first radio link quality of the first TRP and a second radio link quality of the second TRP, and wherein the condition is a degradation of the second DL connection, and the condition is identified based on the first radio link quality and the second radio link quality.

[0147] Clause 19. A computer-readable storage medium according to any one of clauses 16 to 18, wherein the identified condition is a condition for switching at least one of a UL control channel or a UL shared channel of the UL connection, and the device caused to switch the UL connection includes the device caused to switch at least one of the UL control channel or the UL shared channel.

[0148] Clause 20. A computer-readable storage medium according to any one of clauses 16 to 19, wherein the device caused to switch the UL connection includes the device caused to signal the network via the second TRP from the user equipment to request to switch the UL connection to the first TRP.

[0149] Clause 21. An apparatus comprising means for performing the method according to any one of clauses 11 to 15.

[0150] Clause 22. A computer readable medium comprising computer readable program code which, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any one of clauses 22 to 28.

[0151] Clause 23. A computer readable storage medium comprising computer readable program code which, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any one of clauses 11 to 15.

[0152] Clause 24. A computer program comprising computer readable program code which, in response to execution by at least one processing circuitry, causes an apparatus to perform a method according to any one of clauses 11 to 15.

[0153] Clause 25. A device comprising: at least one memory configured to store computer-readable program code; and at least one processing circuit system configured to access the at least one memory and execute the computer-readable program code so that the device at least: collects operating information at a network including a first transmission reception point (TRP) and a second TRP, the operating information including information related to one or more of the first TRP, the second TRP, or a user device connected to both the first TRP and the second TRP, the user device having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP respectively, but having an uplink (UL) connection with the second TRP, and not having a UL connection with the first TRP; performs an evaluation of the operating information of a potential UL failure at either the first TRP or the second TRP; and makes a determination at the network based on the evaluation whether to switch the UL connection from the second TRP to the first TRP.

[0154] Clause 26. An apparatus according to clause 25, wherein the operational information includes beam failure information of at least one of the first TRP or the second TRP.

[0155] Clause 27. An apparatus according to Clause 26, wherein the operating information also includes one or more of the following: the signal strength of at least one of the first TRP or the second TRP, the location of the user device, the speed of the user device, the direction of travel of the user device, or interference in the environment of at least one of the first TRP, the second TRP or the user device.

[0156] Clause 28. An apparatus as described in any of clauses 25 to 27, wherein when the evaluation indicates the potential UL failure at the first TRP, a determination is made not to switch the UL connection.

[0157] Clause 29. An apparatus according to any one of clauses 25 to 28, wherein when the evaluation indicates the potential UL failure at the second TRP, a determination to switch the UL connection is made, and the at least one processing circuit system is configured to execute the computer-readable program code so that the apparatus also at least: switches the UL connection from the second TRP to the first TRP based on the determination.

[0158] Clause 30. An apparatus comprising: a component for collecting operational information at a network including a first transmission reception point (TRP) and a second TRP, the operational information including information related to one or more of the first TRP, the second TRP, or a user equipment connected to both the first TRP and the second TRP, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but having an uplink (UL) connection with the second TRP and not having a UL connection with the first TRP; a component for performing an evaluation of the operational information for a potential UL failure at either the first TRP or the second TRP; and a component for making a determination at the network based on the evaluation whether to switch the UL connection from the second TRP to the first TRP.

[0159] Clause 31. An apparatus according to clause 30, wherein the operational information includes beam failure information of at least one of the first TRP or the second TRP.

[0160] Clause 32. An apparatus according to clause 31, wherein the operating information also includes one or more of the following: the signal strength of at least one of the first TRP or the second TRP, the location of the user device, the speed of the user device, the direction of travel of the user device, or interference in the environment of at least one of the first TRP, the second TRP or the user device.

[0161] Clause 33. An apparatus as described in any of clauses 30 to 32, wherein when the evaluation indicates the potential UL failure at the first TRP, a determination is made not to switch the UL connection.

[0162] Clause 34. An apparatus according to any one of clauses 30 to 33, wherein when the evaluation indicates the potential UL failure at the second TRP, a determination to switch the UL connection is made, and the apparatus further comprises: a switching component for switching the UL connection from the second TRP to the first TRP based on the determination.

[0163] Clause 35. A method comprising: collecting operational information at a network including a first transmission reception point (TRP) and a second TRP, the operational information including information related to one or more of the first TRP, the second TRP, or a user equipment connected to both the first TRP and the second TRP, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but having an uplink (UL) connection with the second TRP and not having a UL connection with the first TRP; performing an evaluation on the operational information of a potential UL failure at either the first TRP or the second TRP; and making a determination at the network based on the evaluation whether to switch the UL connection from the second TRP to the first TRP.

[0164] Clause 36. A method according to clause 35, wherein the operational information includes beam failure information of at least one of the first TRP or the second TRP.

[0165] Clause 37. A method according to Clause 36, wherein the operational information also includes one or more of the following: the signal strength of at least one of the first TRP or the second TRP, the location of the user device, the speed of the user device, the direction of travel of the user device, or interference in the environment of at least one of the first TRP, the second TRP or the user device.

[0166] Clause 38. A method as described in any of clauses 35 to 37, wherein when the evaluation indicates the potential UL failure at the first TRP, a determination is made not to switch the UL connection.

[0167] Clause 39. A method according to any one of clauses 35 to 38, wherein when the evaluation indicates the potential UL failure at the second TRP, a determination to switch the UL connection is made, and the method further comprises: switching the UL connection from the second TRP to the first TRP based on the determination.

[0168] Item 40. A non-transitory computer-readable storage medium having computer-readable program code stored therein, which, in response to execution of the computer-readable program code by at least one processing circuit system, causes the device to at least: collect operational information at a network including a first transmission reception point (TRP) and a second TRP, the operational information including information related to one or more of the first TRP, the second TRP, or a user device connected to both the first TRP and the second TRP, the user device having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but having an uplink (UL) connection with the second TRP and not having a UL connection with the first TRP; perform an evaluation of the operational information of a potential UL failure at either the first TRP or the second TRP; and make a determination at the network based on the evaluation whether to switch the UL connection from the second TRP to the first TRP.

[0169] Clause 41. A computer-readable storage medium according to clause 40, wherein the operational information includes beam failure information of at least one of the first TRP or the second TRP.

[0170] Clause 42. A computer-readable storage medium according to clause 41, wherein the operational information also includes one or more of the following: the signal strength of at least one of the first TRP or the second TRP, the location of the user device, the speed of the user device, the direction of travel of the user device, or interference in the environment of at least one of the first TRP, the second TRP or the user device.

[0171] Clause 43. The computer-readable storage medium of any one of clauses 40 to 42, wherein a determination is made not to switch the UL connection when the evaluation indicates the potential UL failure at the first TRP.

[0172] Clause 44. A computer-readable storage medium according to any one of clauses 40 to 43, wherein when the evaluation indicates the potential UL failure at the second TRP, a determination to switch the UL connection is made, and the computer-readable storage medium has additional computer-readable program code stored therein, the additional computer-readable program code causing the device to at least: switch the UL connection from the second TRP to the first TRP based on the determination in response to execution by the at least one processing circuit system.

[0173] Clause 45. An apparatus comprising means for performing the method of any one of clauses 35 to 39.

[0174] Clause 46. A computer readable medium comprising computer readable program code which, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 35 to 39.

[0175] Clause 47. A computer readable storage medium comprising computer readable program code which, in response to execution by at least one processing circuit system, causes an apparatus to perform the method of any of clauses 35 to 39.

[0176] Clause 48. A computer program comprising computer readable program code which, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 35 to 39.

[0177] Clause 49. An apparatus comprising: a component for detecting a beam failure at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP respectively, but having a UL connection with the second TRP and not having a UL connection with the first TRP, the beam failure being a beam failure of the second DL connection with the second TRP; a component for performing an evaluation of a UL condition of the first TRP; a component for making a determination based on the evaluation to switch the UL connection from the second TRP to the first TRP or the third TRP; and a component for switching the UL connection from the second TRP to the first TRP or the third TRP based on the determination.

[0178] Clause 50. An apparatus according to clause 49, wherein when the determination to switch the UL connection from the second TRP to the first TRP is made, the apparatus further comprises: a component for making a second determination as to whether the user equipment is capable of determining a timing adjustment of the first TRP; and the component for switching the UL connection comprises a component for switching the UL connection from the second TRP to the first TRP based on the second determination.

[0179] Clause 51. An apparatus according to clause 50, wherein when the user equipment is able to determine that the second determination of the timing adjustment of the first TRP is made, the apparatus further comprises: a component for determining the timing adjustment of the first TRP; and using the timing adjustment, the component for switching the UL connection from the second TRP to the first TRP comprises a component for signaling from the user equipment via the first TRP to the network to request switching the UL connection to the first TRP.

[0180] Clause 52. An apparatus according to clause 50 or 51, wherein when the user equipment is unable to determine that the second determination of the timing adjustment is made, the component for switching the UL connection from the second TRP to the first TRP includes: a component for signaling from the user equipment to the network via a preamble code transmission to the first TRP to obtain the timing adjustment; and a component for signaling from the user equipment to the network via the first TRP to request switching the UL connection to the first TRP using the timing adjustment.

[0181] Clause 53. An apparatus according to any one of clauses 49 to 52, wherein when the determination to switch the UL connection from the second TRP to the third TRP is made, the apparatus further comprises: a component for signaling from the user equipment to the network via a preamble code transmission to the third TRP to obtain a timing adjustment for the third TRP; and a component for signaling from the user equipment to the network via the third TRP to request switching the UL connection to the third TRP using the timing adjustment.

[0182] Clause 54. A device comprising: at least one memory configured to store computer-readable program code; and at least one processing circuit system configured to access the at least one memory and execute the computer-readable program code so that the device at least: detects a beam failure at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP respectively, but having a UL connection with the second TRP and not having a UL connection with the first TRP, the beam failure being a beam failure of the second DL connection with the second TRP; performs an evaluation of the UL condition of the first TRP; makes a determination based on the evaluation to switch the UL connection from the second TRP to the first TRP or the third TRP; and switches the UL connection from the second TRP to the first TRP or the third TRP based on the determination.

[0183] Clause 55. An apparatus according to clause 54, wherein when the determination to switch the UL connection from the second TRP to the first TRP is made, the at least one processing circuit system is configured to execute the computer-readable program code so that the apparatus also at least: makes a second determination as to whether the user equipment is capable of determining a timing adjustment of the first TRP; and switching the UL connection includes switching the UL connection from the second TRP to the first TRP based on the second determination.

[0184] Clause 56. An apparatus according to clause 55, wherein when the user equipment is capable of determining that the second determination of the timing adjustment of the first TRP is made, the at least one processing circuit system is configured to execute the computer-readable program code so that the apparatus also at least: determines the timing adjustment of the first TRP; and using the timing adjustment, switching the UL connection from the second TRP to the first TRP includes signaling from the user equipment to the network via the first TRP to request switching the UL connection to the first TRP.

[0185] Clause 57. An apparatus according to clause 55 or 56, wherein when the user equipment is unable to determine that the second determination of the timing adjustment has been made, switching the UL connection from the second TRP to the first TRP includes: signaling from the user equipment to the network via a preamble code transmission to the first TRP to obtain the timing adjustment; and using the timing adjustment, signaling from the user equipment to the network via the first TRP to request switching the UL connection to the first TRP.

[0186] Clause 58. An apparatus according to any one of clauses 54 to 57, wherein when the determination to switch the UL connection from the second TRP to the third TRP is made, the at least one processing circuit system is configured to execute the computer-readable program code so that the apparatus further at least: signals the network from the user equipment via a preamble code transmission to the third TRP to obtain a timing adjustment of the third TRP; and uses the timing adjustment to signal the network from the user equipment via the third TRP to request switching the UL connection to the third TRP.

[0187] Clause 59. A method comprising: detecting a beam failure at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP respectively, but having a UL connection with the second TRP and not having a UL connection with the first TRP, the beam failure being a beam failure of the second DL connection with the second TRP; performing an evaluation of the UL condition of the first TRP; making a determination based on the evaluation to switch the UL connection from the second TRP to the first TRP or the third TRP; and switching the UL connection from the second TRP to the first TRP or the third TRP based on the determination.

[0188] Clause 60. A method according to Clause 59, wherein when the determination to switch the UL connection from the second TRP to the first TRP is made, the method further includes: making a second determination whether the user equipment is capable of determining the timing adjustment of the first TRP; and switching the UL connection includes switching the UL connection from the second TRP to the first TRP based on the second determination.

[0189] Clause 61. A method according to clause 60, wherein when the user equipment is able to determine that the second determination of the timing adjustment of the first TRP is made, the method further includes: determining the timing adjustment of the first TRP; and using the timing adjustment, switching the UL connection from the second TRP to the first TRP includes signaling from the user equipment to the network via the first TRP to request switching the UL connection to the first TRP.

[0190] Clause 62. A method according to clause 60 or 61, wherein when the user equipment is unable to determine that the second determination of the timing adjustment has been made, switching the UL connection from the second TRP to the first TRP includes: signaling from the user equipment to the network via a preamble code transmission to the first TRP to obtain the timing adjustment; and using the timing adjustment, signaling from the user equipment to the network via the first TRP to request switching the UL connection to the first TRP.

[0191] Clause 63. A method according to any one of clauses 59 to 62, wherein when the determination to switch the UL connection from the second TRP to the third TRP is made, the method further comprises: signaling from the user equipment to the network via a preamble code transmission to the third TRP to obtain a timing adjustment of the third TRP; and using the timing adjustment, signaling from the user equipment to the network via the third TRP to request switching the UL connection to the third TRP.

[0192] Clause 64. A non-transitory computer-readable storage medium having computer-readable program code stored therein, which, in response to execution of the computer-readable program code by at least one processing circuit system, causes the device to at least: detect a beam failure at a user device connected to both a first transmission reception point (TRP) and a second TRP of a network, the user device having a first downlink (DL) connection and a second DL connection respectively with the first TRP and the second TRP, but having a UL connection with the second TRP and not having a UL connection with the first TRP, the beam failure being a beam failure of the second DL connection with the second TRP; perform an evaluation of the UL condition of the first TRP; make a determination based on the evaluation to switch the UL connection from the second TRP to the first TRP or the third TRP; and switch the UL connection from the second TRP to the first TRP or the third TRP based on the determination.

[0193] Clause 65. A computer-readable storage medium according to clause 64, wherein when the determination to switch the UL connection from the second TRP to the first TRP is made, additional computer-readable program code is stored in the computer-readable storage medium, and the additional computer-readable program code, in response to execution by the at least one processing circuit system, causes the device to at least: make a second determination as to whether the user equipment is capable of determining the timing adjustment of the first TRP; and switching the UL connection includes switching the UL connection from the second TRP to the first TRP based on the second determination.

[0194] Clause 66. A computer-readable storage medium according to clause 65, wherein when the user equipment is capable of determining that the second determination of the timing adjustment of the first TRP is made, the computer-readable storage medium has additional computer-readable program code stored therein, and the additional computer-readable program code, in response to execution by the at least one processing circuit system, causes the device to further at least: determine the timing adjustment of the first TRP; and using the timing adjustment, switching the UL connection from the second TRP to the first TRP includes signaling from the user equipment to the network via the first TRP to request that the UL connection be switched to the first TRP.

[0195] Clause 67. A computer-readable storage medium according to clause 65 or 66, wherein when the user equipment is unable to determine that the second determination of the timing adjustment is made, switching the UL connection from the second TRP to the first TRP includes: signaling from the user equipment to the network via a preamble code transmission to the first TRP to obtain the timing adjustment; and using the timing adjustment, signaling from the user equipment to the network via the first TRP to request switching the UL connection to the first TRP.

[0196] Clause 68. A computer-readable storage medium according to any one of clauses 64 to 67, wherein when the determination to switch the UL connection from the second TRP to the third TRP is made, the computer-readable storage medium has additional computer-readable program code stored therein, and the additional computer-readable program code, in response to execution by the at least one processing circuit system, causes the device to at least: send a signal from the user equipment to the network via a preamble code transmission to the third TRP to obtain a timing adjustment of the third TRP; and use the timing adjustment to send a signal from the user equipment to the network via the third TRP to request switching the UL connection to the third TRP.

[0197] Clause 69. An apparatus comprising means for performing the method of any one of clauses 59 to 63.

[0198] Clause 70. A computer readable medium comprising computer readable program code, the computer readable program code in response to execution by at least one processing circuit system causing an apparatus to perform the method of any of clauses 59 to 63.

[0199] Clause 71. A computer readable storage medium comprising computer readable program code, the computer readable program code in response to execution by at least one processing circuit system causing an apparatus to perform the method of any of clauses 59 to 63.

[0200] Clause 72. A computer program comprising computer readable program code which, in response to execution by at least one processing circuitry, causes an apparatus to perform a method according to any one of clauses 59 to 63.

[0201] Clause 73. A device comprising: at least one memory configured to store computer-readable program code; and at least one processing circuit system configured to access the at least one memory and execute the computer-readable program code so that the device at least: detects a beam failure at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP respectively, but having a UL connection with the second TRP and not having a UL connection with the first TRP, the beam failure being a beam failure of the first DL connection with the first TRP; evaluating the propagation delay difference between the first TRP and the second TRP; making a determination based on the propagation delay difference whether to utilize the first TRP or to perform a beam recovery process to recover the first DL connection through the UL connection with the second TRP; and performing the beam recovery process based on the determination.

[0202] Clause 74. An apparatus according to clause 73, wherein the determination is made based on the propagation delay difference and a threshold difference, and the threshold difference is the length of a protection period between data units sent by the first TRP and the second TRP.

[0203] Clause 75. An apparatus according to clause 73 or 74, wherein the determination to perform the beam recovery process using the first TRP is made when the propagation delay difference is less than a threshold difference.

[0204] Clause 76. An apparatus according to any one of clauses 73 to 75, wherein when the propagation delay difference is greater than a threshold difference, the determination to perform the beam recovery process via the UL connection with the second TRP is made.

[0205] Clause 77. An apparatus according to clause 76, wherein performing the beam recovery process through the UL connection with the second TRP includes: sending a signal from the user equipment to the network via the UL connection with the second TRP to indicate a candidate DL beam of the first TRP for recovering the first DL connection; and receiving a message from the network at the user equipment via the UL connection with the second TRP to indicate that the user equipment switches to the candidate DL beam, or confirms switching to the candidate DL beam.

[0206] Clause 78. An apparatus comprising: a component for detecting a beam failure at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP respectively, but having a UL connection with the second TRP and not having a UL connection with the first TRP, the beam failure being a beam failure of the first DL connection with the first TRP; a component for evaluating a propagation delay difference between the first TRP and the second TRP; a component for making a determination based on the propagation delay difference whether to utilize the first TRP or to perform a beam recovery process to recover the first DL connection through the UL connection with the second TRP; and a component for performing the beam recovery process based on the determination.

[0207] Clause 79. An apparatus according to clause 78, wherein the determination is made based on the propagation delay difference and a threshold difference, and the threshold difference is the length of a protection period between data units sent by the first TRP and the second TRP.

[0208] Clause 80. An apparatus according to clause 78 or 79, wherein the determination to perform the beam recovery process using the first TRP is made when the propagation delay difference is less than a threshold difference.

[0209] Clause 81. An apparatus according to any one of clauses 78 to 80, wherein when the propagation delay difference is greater than a threshold difference, the determination to perform the beam recovery process via the UL connection with the second TRP is made.

[0210] Clause 82. An apparatus according to clause 81, wherein the component for performing the beam recovery process through the UL connection with the second TRP includes: a component for sending a signal from the user equipment to the network via the UL connection with the second TRP to indicate a candidate DL beam of the first TRP for recovering the first DL connection; and a component for receiving a message at the user equipment from the network via the UL connection with the second TRP to indicate that the user equipment switches to the candidate DL beam or confirms switching to the candidate DL beam.

[0211] Clause 83. A method comprising: detecting a beam failure at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP respectively, but having a UL connection with the second TRP and not having a UL connection with the first TRP, the beam failure being a beam failure of the first DL connection with the first TRP; evaluating a propagation delay difference between the first TRP and the second TRP; determining based on the propagation delay difference whether to perform a beam recovery process to recover the first DL connection using the first TRP or through the UL connection with the second TRP; and performing the beam recovery process based on the determination.

[0212] Clause 84. A method according to clause 83, wherein the determination is made based on the propagation delay difference and a threshold difference, and the threshold difference is the length of a protection period between data units sent by the first TRP and the second TRP.

[0213] Clause 85. A method according to clause 83 or 84, wherein when the propagation delay difference is less than a threshold difference, the determination to perform the beam recovery process using the first TRP is made.

[0214] Clause 86. A method according to any one of clauses 83 to 85, wherein when the propagation delay difference is greater than a threshold difference, the determination to perform the beam recovery process via the UL connection with the second TRP is made.

[0215] Clause 87. A method according to clause 86, wherein performing the beam recovery process through the UL connection with the second TRP includes: sending a signal from the user equipment to the network via the UL connection with the second TRP to indicate a candidate DL beam of the first TRP for recovering the first DL connection; and receiving a message from the network at the user equipment via the UL connection with the second TRP to indicate that the user equipment switches to the candidate DL beam, or confirms switching to the candidate DL beam.

[0216] Clause 88. A non-transitory computer-readable storage medium having computer-readable program code stored therein, which, in response to execution of the computer-readable program code by at least one processing circuit system, causes the device to at least: detect a beam failure at a user device connected to both a first transmission reception point (TRP) and a second TRP of a network, the user device having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP respectively, but having a UL connection with the second TRP and not having a UL connection with the first TRP, the beam failure being a beam failure of the first DL connection with the first TRP; evaluate the propagation delay difference between the first TRP and the second TRP; make a determination based on the propagation delay difference whether to utilize the first TRP or to perform a beam recovery process to recover the first DL connection through the UL connection with the second TRP; and perform the beam recovery process based on the determination.

[0217] Clause 89. A computer-readable storage medium as described in clause 88, wherein the determination is made based on the propagation delay difference and a threshold difference, and the threshold difference is the length of a protection period between data units sent by the first TRP and the second TRP.

[0218] Clause 90. A computer-readable storage medium according to clause 88 or 89, wherein the determination to perform the beam recovery process using the first TRP is made when the propagation delay difference is less than a threshold difference.

[0219] Clause 91. A computer-readable storage medium as described in any of clauses 88 to 90, wherein when the propagation delay difference is greater than a threshold difference, the determination to perform the beam recovery process via the UL connection with the second TRP is made.

[0220] Clause 92. A computer-readable storage medium according to clause 91, wherein performing the beam recovery process through the UL connection with the second TRP includes: sending a signal from the user equipment to the network via the UL connection with the second TRP to indicate a candidate DL beam of the first TRP for recovering the first DL connection; and receiving a message from the network at the user equipment via the UL connection with the second TRP to indicate that the user equipment switches to the candidate DL beam, or confirms switching to the candidate DL beam.

[0221] Clause 93. An apparatus comprising means for performing the method of any of clauses 83 to 87.

[0222] Clause 94. A computer readable medium comprising computer readable program code, the computer readable program code in response to execution by at least one processing circuit system causing an apparatus to perform the method of any of clauses 83 to 87.

[0223] Clause 95. A computer readable storage medium comprising computer readable program code, the computer readable program code in response to execution by at least one processing circuit system causing an apparatus to perform the method of any of clauses 83 to 87.

[0224] Clause 96. A computer program comprising computer readable program code which, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 83 to 87.

[0225] Benefiting from the teachings presented in the foregoing description and the associated drawings, a person skilled in the art to which the present disclosure belongs will think of many modifications and other implementations of the present disclosure. Therefore, it should be understood that the present disclosure is not limited to the specific implementation disclosed, and modifications and other implementations are intended to be included within the scope of the appended claims. In addition, although the foregoing description and the associated drawings describe example implementations in the context of certain example combinations of elements and / or functions, it should be understood that different combinations of elements and / or functions can be provided by alternative implementations without departing from the scope of the appended claims. In this regard, for example, as described in some of the appended claims, it is also possible to consider elements and functional combinations different from the elements and / or functions explicitly described above. Although specific terms are used herein, they are only used in a general and descriptive sense, not for the purpose of limitation.

Claims

1. A device for communication, comprising: at least one memory configured to store computer readable program code; as well as At least one processing circuit system is configured to access the at least one memory and execute the computer readable program code so that the apparatus performs at least the following: monitoring a radio link quality at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but having an uplink (UL) connection with the second TRP and not having a UL connection with the first TRP, the monitored radio link quality being a radio link quality of the second DL connection with the second TRP; identifying a condition for switching the UL connection based at least on the radio link quality of the second DL connection; as well as Based on the determination, the UL connection is switched from the second TRP to the first TRP.

2. The apparatus according to claim 1, configured to perform: signaling, from the user equipment via the second TRP to the network, user equipment capabilities, the user equipment capabilities including the ability to switch between TRPs; and Radio resource control signaling is received at the user equipment from the network via the second TRP to implement the capability at the user equipment.

3. The apparatus according to claim 1 or 2, wherein monitoring the radio link quality comprises: monitoring a first radio link quality of the first TRP and a second radio link quality of the second TRP, and Wherein the condition is a degradation of the second DL connection, and the condition is identified based on the first radio link quality and the second radio link quality.

4. The apparatus according to claim 1 or 2, wherein the identified condition is a condition for switching at least one of a UL control channel or a UL shared channel of the UL connection, and switching the UL connection comprises: At least one of the UL control channel or the UL shared channel is switched.

5. The apparatus according to claim 1 or 2, wherein switching the UL connection comprises: Signaling is sent from the user equipment to the network via the second TRP to request switching of the UL connection to the first TRP.

6. A device for communication, comprising: at least one memory configured to store computer readable program code; as well as At least one processing circuit system is configured to access the at least one memory and execute the computer readable program code so that the apparatus performs at least the following: collecting operational information at a network including a first transmission reception point (TRP) and a second TRP, the operational information including: information related to one or more of the first TRP, the second TRP, or a user equipment connected to both the first TRP and the second TRP, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but having an uplink (UL) connection with the second TRP and not having a UL connection with the first TRP; performing an evaluation of the operational information for a potential UL failure at either the first TRP or the second TRP; as well as Based on the evaluation, a determination is made at the network whether to switch the UL connection from the second TRP to the first TRP.

7. The apparatus according to claim 6, wherein the operation information comprises: Beam failure information of at least one of the first TRP or the second TRP.

8. The apparatus according to claim 7, wherein the operation information further comprises one or more of the following: The signal strength of at least one of the first TRP or the second TRP, the location of the user equipment, the speed of the user equipment, the direction of travel of the user equipment, or interference in the environment of at least one of the first TRP, the second TRP or the user equipment.

9. An apparatus according to claim 6 or 7, wherein when the evaluation indicates the potential UL failure at the first TRP, a determination is made not to switch the UL connection.

10. The apparatus of claim 6 or 7, wherein when the evaluation indicates the potential UL failure at the second TRP, a determination is made to switch the UL connection, and the method further comprises: Based on the determination, the UL connection is switched from the second TRP to the first TRP.

11. An apparatus for communication, comprising: at least one memory configured to store computer readable program code; as well as At least one processing circuit system is configured to access the at least one memory and execute the computer readable program code so that the apparatus performs at least the following: detecting a beam failure at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but having an UL connection with the second TRP and not having an UL connection with the first TRP, the beam failure being a beam failure of the second DL connection with the second TRP; performing an evaluation of the UL condition of the first TRP; Based on the evaluation, making a determination to switch the UL connection from the second TRP to the first TRP or a third TRP; as well as Based on the determination, the UL connection is switched from the second TRP to the first TRP or the third TRP.

12. The apparatus of claim 11, wherein when the determination to switch the UL connection from the second TRP to the first TRP is made, the apparatus is further configured to perform: making a second determination whether the user equipment is capable of determining a timing adjustment for the first TRP; and Switching the UL connection includes: Based on the second determination, the UL connection is switched from the second TRP to the first TRP.

13. The apparatus of claim 12, wherein when the user equipment is able to determine that the second determination of the timing adjustment of the first TRP is made, the apparatus is further configured to perform: determining the timing adjustment of the first TRP; and using the timing adjustment, Switching the UL connection from the second TRP to the first TRP includes: Signaling is sent from the user equipment to the network via the first TRP to request switching of the UL connection to the first TRP.

14. The apparatus of claim 12 or 13, wherein when the user equipment is unable to determine that the second determination of the timing adjustment is made, switching the UL connection from the second TRP to the first TRP comprises: signaling from the user equipment to the network via a preamble transmission to the first TRP to obtain the timing adjustment; and using the timing adjustment, Signaling is sent from the user equipment to the network via the first TRP to request switching of the UL connection to the first TRP.

15. The apparatus of claim 11 or 12, wherein when the determination to switch the UL connection from the second TRP to the third TRP is made, the apparatus is further configured to perform: signaling from the user equipment to the network via a preamble transmission to the third TRP to obtain a timing adjustment for the third TRP; and using the timing adjustment, Signaling is sent from the user equipment to the network via the third TRP to request switching of the UL connection to the third TRP.

16. An apparatus for communication, comprising: at least one memory configured to store computer readable program code; as well as At least one processing circuit system is configured to access the at least one memory and execute the computer readable program code so that the apparatus performs at least the following: detecting a beam failure at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but having an UL connection with the second TRP and not having an UL connection with the first TRP, the beam failure being a beam failure of the first DL connection with the first TRP; evaluating a propagation delay difference between the first TRP and the second TRP; making a determination, based on the propagation delay difference, whether to perform a beam recovery procedure to recover the first DL connection using the first TRP or through the UL connection with the second TRP; as well as The beam recovery process is performed based on the determination.

17. The apparatus of claim 16, wherein the determination is made based on the propagation delay difference and a threshold difference, and the threshold difference is the length of a protection period between data units sent by the first TRP and the second TRP.

18. An apparatus according to claim 16 or 17, wherein when the propagation delay difference is less than a threshold difference, the determination to perform the beam recovery process using the first TRP is made.

19. An apparatus according to claim 16 or 17, wherein when the propagation delay difference is greater than a threshold difference, the determination to perform the beam recovery process through the UL connection with the second TRP is made.

20. The apparatus of claim 19, wherein performing the beam recovery process through the UL connection with the second TRP comprises: signaling from the user equipment to the network via the UL connection with the second TRP to indicate a candidate DL beam of the first TRP for resuming the first DL connection; and A message is received at the user equipment from the network via the UL connection with the second TRP to indicate that the user equipment switches to the candidate DL beam, or confirms switching to the candidate DL beam.

21. A method for communication, comprising: monitoring a radio link quality at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but having an uplink (UL) connection with the second TRP and not having a UL connection with the first TRP, the monitored radio link quality being a radio link quality of the second DL connection with the second TRP; identifying a condition for switching the UL connection based at least on the radio link quality of the second DL connection; as well as Based on the determination, the UL connection is switched from the second TRP to the first TRP.

22. A method for communication, comprising: collecting operational information at a network including a first transmission reception point (TRP) and a second TRP, the operational information including: information related to one or more of the first TRP, the second TRP, or a user equipment connected to both the first TRP and the second TRP, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but having an uplink (UL) connection with the second TRP and not having a UL connection with the first TRP; performing an evaluation of the operational information for a potential UL failure at either the first TRP or the second TRP; and Based on the evaluation, a determination is made at the network whether to switch the UL connection from the second TRP to the first TRP.

23. A method for communication, comprising: detecting a beam failure at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but having an UL connection with the second TRP and not having an UL connection with the first TRP, the beam failure being a beam failure of the second DL connection with the second TRP; performing an evaluation of the UL condition of the first TRP; Based on the evaluation, making a determination to switch the UL connection from the second TRP to the first TRP or a third TRP; as well as Based on the determination, the UL connection is switched from the second TRP to the first TRP or the third TRP.

24. A method for communication, comprising: detecting a beam failure at a user equipment connected to both a first transmission reception point (TRP) and a second TRP of a network, the user equipment having a first downlink (DL) connection and a second DL connection with the first TRP and the second TRP, respectively, but having an UL connection with the second TRP and not having an UL connection with the first TRP, the beam failure being a beam failure of the first DL connection with the first TRP; evaluating a propagation delay difference between the first TRP and the second TRP; making a determination, based on the propagation delay difference, whether to perform a beam recovery procedure to recover the first DL connection using the first TRP or through the UL connection with the second TRP; as well as The beam recovery process is performed based on the determination.

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