First network node, second network node, third network node, device and methods performed thereby, for handling mobility

Abstract

A method performed by a first network node (111). The method is for handling mobility. The first network node (111) operates in a communications network (100). The first network node (111) sends (205) a first message to a second network node (112) operating in the communications network (100). The first message comprises a first indication indicating one or more L1 / L2-Triggered Mobility (LTM) procedures for a device (130) operating in the communications network (100). The first message indicates one or more target cells or beams.

Description

[0001] FIRST NETWORK NODE, SECOND NETWORK NODE, THIRD NETWORK NODE, DEVICE AND METHODS PERFORMED THEREBY, FOR HANDLING MOBILITY

[0002] TECHNICAL FIELD

[0003] The present disclosure relates generally to a first network node and methods performed thereby for handling mobility. The present disclosure also relates generally to a second network node and methods performed thereby for handling mobility. The present disclosure further relates generally to a third network node and methods performed thereby for handling mobility. The present disclosure also relates generally to a device and methods performed thereby for handling mobility. The present disclosure also relates generally to a computer program and computer-readable storage medium, having stored thereon the computer program to carry out this method.

[0004] BACKGROUND

[0005] Wireless devices within a wireless communications network may be e.g., User Equipments (UEs), stations (STAs), mobile terminals, wireless terminals, terminals, and / or Mobile Stations (MS). Wireless devices are enabled to communicate wirelessly in a cellular communications network or wireless communication network, sometimes also referred to as a cellular radio system, cellular system, or cellular network. The communication may be performed e.g., between two wireless devices, between a wireless device and a regular telephone and / or between a wireless device and a server via a Radio Access Network (RAN) and possibly one or more core networks, comprised within the wireless communications network. Wireless devices may further be referred to as mobile telephones, cellular telephones, laptops, or tablets with wireless capability, just to mention some further examples. The wireless devices in the present context may be, for example, portable, pocket-storable, hand-held, computer-comprised, or vehicle-mounted mobile devices, enabled to communicate voice and / or data, via the RAN, with another entity, such as another terminal or a server.

[0006] The wireless communications network covers a geographical area which may be divided into cell areas, each cell area being served by a network node, which may be an access node such as a radio network node, radio node or a base station, e.g., a Radio Base Station (RBS), which sometimes may be referred to as e.g., gNB, evolved Node B (“eNB”), “eNodeB”, “NodeB”, “B node”, Transmission Point (TP), or Base Transceiver Station (BTS), depending on the technology and terminology used. The base stations may be of different classes such as e.g., Wide Area Base Stations, Medium Range Base Stations, Local Area Base Stations, Home Base Stations, pico base stations, etc... , based on transmission power and thereby also cell size. A cell is the geographical area where radio coverage is provided by the base station or radio node at a base station site, or radio node site, respectively. One base station, situated on the base station site, may serve one or several cells. Further, each base station may support one or several communication technologies. The base stations communicate over the air interface operating on radio frequencies with the terminals within range of the base stations. The network nodes may serve receiving nodes, such as wireless devices, with serving beams. In some of such scenarios, the wireless communications network may be a non-cellular system. In 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE), base stations, which may be referred to as eNodeBs or even eNBs, may be directly connected to one or more core networks. In the context of this disclosure, the expression Downlink (DL) may be used for the transmission path from the base station to the wireless device. The expression Uplink (UL) may be used for the transmission path in the opposite direction i.e., from the wireless device to the base station.

[0007] The standardization organization 3GPP is currently in the process of specifying a New Radio Interface called NR or 5G-UTRA, as well as a Fifth Generation (5G) Packet Core Network (CN), which may be referred to as Next Generation (NG) Core Network, abbreviated as NG-CN, NGC, 5G CN or 5G Core (5GC). NG may be understood to refer to the interface / reference point between the Radio Access Network (RAN) and the CN in 5G / NR. In a 5G System (5GS), a radio base station in NR may be referred to as a gNB or 5G Node B. An NR UE may be referred to as an nUE.

[0008] Layer 1 (L1) / Layer 2 (L2) based inter-cell mobility in Rel-18

[0009] In 3GPP Release 18, a work item known as Further NR mobility enhancements has been agreed. This work item includes a technical area entitled L1 / L2 based inter-cell mobility. According to the Work Item Description (WID) [1], when a UE moves from the coverage area of one cell to another cell, at some point, a serving cell change may need to be performed. Currently, serving cell change may be triggered by L3 measurements and may be done by Radio Resource Control (RRC) signalling triggered Reconfiguration with Synchronisation for change of Primary Cell (PCell) and PSCell, that is, Primary Secondary Cell, in LTE, or Primary Secondary Cell Group (SCG) Cell, in NR, as well as release of Secondary Cells (SCells) when applicable. All cases may involve complete L2, and L1 , resets, leading to longer latency, larger overhead and longer interruption time than beam switch mobility. The goal of L1 / L2 based inter-cell mobility may be understood to be to enable a serving cell change via L1 / L2 signalling, in order to reduce the latency, overhead and interruption time.

[0010] In this work item, according to the WID [1], to specify mechanism and procedures of L1 / L2 based inter-cell mobility for mobility latency reduction may be included as one objective of the work. This may include configuration and maintenance for multiple candidate cells to allow fast application of configurations for candidate cells, a dynamic switch mechanism among candidate serving cells, including Special Cell (SpCell), the primary cell of a master or secondary cell group, and SCell, for the potential applicable scenarios based on L1 / L2 signalling, L1 enhancements for inter-cell beam management, including L1 measurement and reporting, and beam indication, Timing Advance management and Central Unit (CU)- Distributed Unit (DU) interface signalling to support L1 / L2 mobility, if needed. Frequency 2 (FR2) specific enhancements were not precluded, if any.

[0011] The procedure of L1 / L2 based inter-cell mobility may be applicable to the following scenarios: Standalone, Carrier Aggregation (CA) and NR-Dual Connectivity (DC) case with serving cell change within one Cell Group (CG), intra-Distributed Unit (DU) case and intra- Central Unit (CU) inter-DU case, applicable for Standalone and CA: no new RAN interfaces are expected, both intra-frequency and inter-frequency, and both Frequency 1 (FR1) and FR2. Source and target cells may be synchronized or non-synchronized

[0012] The overall procedures for L1 / L2-Triggered Mobility (LTM) in Rel-18 may be as described in 3GPP TS 38.300 [3], subclause 9.2.3.5, and for the gNB-CU / gNB-DU Architecture in 3GPP TS 38.401 [4], subclauses 8.2.1.4-8.2.1.6.

[0013] A basic principle with L1 / L2 triggered mobility (LTM) may be understood to be that a UE may be pre-configured, by the network, with an LTM configuration which may include information such as measurement configuration and an RRC configuration per LTM candidate cell, sometimes also known as an LTM candidate cell configuration. Such an LTM candidate cell configuration may be an RRCReconfiguration message or one or more Information Elements (IEs) / fields / parameters such as CellGroupConfig. The UE may perform measurements on LTM candidate cells and beams in those cells, according to the measurement configuration included in the LTM configuration received by the network. The UE may transmit L1 measurement reports for LTM including L1 -Reference Signal Received Power (RSRP) measurements for up to four LTM candidate cells and up to four beams in in each cell. When the network, e.g., a gNB or a gNB-DU, receives the L1 measurement report for LTM, it may use the content of this report to trigger an LTM cell switch towards one of the LTM candidate cells.

[0014] With the introduction of LTM, a functionality may be added where the UE may perform early synchronization to cells different from the current serving cell as a way to reduce the interruption and latency during the actual mobility procedure, also known as an LTM cell switch procedure in case of using it for L1 / L2-Triggered Mobility. The procedure for early DL sync, also known as early Transmission Configuration Indication (TCI) state activation, may be triggered by the network by transmitting an early TCI state activation Medium Access Control (MAC) Control Element (CE) to the UE. The UE may then activate the indicated TCI state(s) for the neighbor cell. When the UE has performed early downlink (DL) sync for a cell prior to the mobility procedure, the delay caused by UE establishing DL sync towards that cell during the actual execution of the mobility procedure may be avoided. One procedure for early UL sync, also known as early Timing Advance (TA) acquisition, may be triggered by the network transmitting a Physical Downlink Control Channel (PDCCH) order to the UE. The UE may then transmit a random access preamble in the indicated neighbor cell and the target node controlling the neighbor cell may calculate a TA which may then be provided to the UE via the source node during the mobility procedure, such as LTM cell switch. As the UE may have a valid TA for that cell, the use of random access towards that cell during the actual mobility procedure may be avoided.

[0015] The network may trigger the execution of an LTM cell switch procedure in the UE to one of these LTM candidate cells by transmitting an LTM cell switch command MAC Control Element (MAC CE), to the UE. The LTM cell switch command may include information, such as a reference to an LTM candidate cell configuration and an indication of a target beam in the LTM candidate cell. The UE may then connect to the beam and switch to the LTM candidate cell configuration.

[0016] L3 measurements triggered LTM

[0017] Based on the question from RAN2, RAN4 agreed the Liaison Statement (LS) in R4- 2410303. For whether intra-frequency and inter-frequency L1 measurements and reporting are prerequisites to support intra-frequency and inter-frequency LTM, RAN4 analysed RAN4 requirements and achieved the following agreements. For FR1, RAN4 Rel-18 related LTM requirements may be applicable to the case without L1 measurement and reporting of LTM candidate cells. For FR2, RAN4 Rel-18 related LTM requirements may be not applicable if L1 measurements for LTM candidate cells are not supported by the UE, or not configured by the network. Furthermore, RAN2 sent an LS to RAN3 in R2-2407606. As the overall description, in the late phase of Rel-18 LTM definition, it was decided that LTM may be triggered based on Layer 3 measurements by the UE. Consequently, Layer 3 measurements may be delivered via RRC to the CU and the CU may need to request the DU to send MAC CE to trigger LTM execution. During RAN2 discussion, it was recognised, that there is no message over F1 which would be sent from CU to DU requesting to trigger MAC CE for the case that the LTM mobility is based on L3 measurements. It was also recognised that such a message would be needed from Release 18 onwards. In terms of actions, RAN2 asked RAN3 to introduce F1 support for the case where the CU may need to request the DU to send MAC CE to trigger LTM execution based on UE Layer 3 measurements. Based on that, RAN3 may consider the signalling change to support the above.

[0018] SUMMARY

[0019] It is an object of embodiments herein to improve the handling of mobility in a communications network.

[0020] According to a first aspect of embodiments herein, the object is achieved by a computer- implemented method, performed by a first network node. The method is for handling mobility. The first network node operates in a communications network. The first network node sends a first message to a second network node operating in the communications network. The first message comprises a first indication. The first indication indicates one or more LTM procedures for a device operating in the communications network. The first message indicates one or more target cells or beams.

[0021] According to a second aspect of embodiments herein, the object is achieved by a computer-implemented method, performed by the second network node. The method is for handling mobility. The second network node operates in the communications network. The second network node receives the first message from the first network node operating in the communications network. The first message comprises the first indication. The first indication indicates the one or more LTM procedures for the device operating in the communications network. The first message indicates the one or more target cells or beams.

[0022] According to a third aspect of embodiments herein, the object is achieved by a computer- implemented method, performed by a third network node. The method is for handling mobility. The third network node operates in the communications network. The third network node receives the second indication from the first network node operating in the communications network. The second indication requests whether or not the one or more LTM procedures are possible. The third network node also sends the third indication to the first network node. The sending is responsive to the received second indication. The third indication indicates whether or not the one or more LTM procedures are possible.

[0023] According to a fourth aspect of embodiments herein, the object is achieved by a computer-implemented method, performed by a device. The method is for handling mobility. The 130 operates in the communications network. The device sends the previous message. The sending is to the first network node operating in the communications network. The previous message indicates the one or more L3 measurements. The device receives the another indication from the second network node managed by the first network node. The another indication instructs the device to perform the one or more LTM procedures. The receiving of the another indication is based on the sent previous message.

[0024] According to a fifth aspect of embodiments herein, the object is achieved by the first network node. The first network node is for handling mobility. The first network node is configured to operate in the communications network. The first network node is configured to send the first message to the second network node configured to operate in the communications network. The first message is configured to comprise the first indication configured to indicate the one or more LTM procedures for the device configured to operate in the communications network. The first message is configured to indicate the one or more target cells or beams.

[0025] According to a sixth aspect of embodiments herein, the object is achieved by the second network node. The second network node is for handling the mobility. The second network node is configured to operate in the communications network. The second network node is configured to receive the first message from the first network node configured to operate in the communications network. The first message is configured to comprise the first indication configured to indicate the one or more LTM procedures for the device configured to operate in the communications network. The first message is configured to indicate the one or more target cells or beams.

[0026] According to a seventh aspect of embodiments herein, the object is achieved by the third network node. The third network node is for handling mobility. The third network node is configured to operate in the communications network. The third network node is configured to receive the second indication from the first network node configured to operate in the communications network. The second indication is configured to request whether or not the one or more LTM procedures are possible. The third network node is also configured to send, responsive to the second indication configured to be received, the third indication to the first network node. The third indication is configured to indicate whether or not the one or more LTM procedures are possible.

[0027] According to an eighth aspect of embodiments herein, the object is achieved by the device. The device is for handling mobility. The device is configured to operate via the communications network. The device is configured to send the previous message to the first network node configured to operate in the communications network. The previous message is configured to indicate the one or more L3 measurements. The device is configured to receive the another indication from the second network node configured to be managed by the first network node. The another indication is configured to instruct the device to perform the one or more LTM procedures. The receiving of the another indication is configured to be based on the previous message configured to be sent.

[0028] By sending the first message to the second network node, the first message comprising the first indication indicating the one or more LTM procedures for the device, and the one or more target cells or beams, the first network node may enable the second network node to trigger the one or more LTM procedures, e.g., by sending the another indication to the device. This may avoid that the device may perform some measurements on candidate cells, and report those measurements to the network, which may decrease implementation complexity in the device, and the first network node and may also decrease power consumption at the device.

[0029] By the third network node receiving the second indication from the first network node, the second indication being configured to request whether or not the one or more LTM procedures are possible, the third network node .

[0030] BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Examples of embodiments herein are described in more detail with reference to the accompanying drawings, according to the following description.

[0032] Figure 1 is a schematic diagram depicting an example of a communications network, according to embodiments herein.

[0033] Figure 2 is a flowchart depicting a method in a first network node, according to embodiments herein.

[0034] Figure 3 is a flowchart depicting a method in a second network node, according to embodiments herein.

[0035] Figure 4 is a flowchart depicting a method in a third network node, according to embodiments herein.

[0036] Figure 5 is a flowchart depicting a method in a device, according to embodiments herein.

[0037] Figure 6 is a flowchart depicting a non-limiting example of signalling in a communications network, according to embodiments herein.

[0038] Figure 7 is a flowchart depicting another non-limiting example of signalling in a communications network, according to embodiments herein.

[0039] Figure 8 is a flowchart depicting yet another non-limiting example of signalling in a communications network, according to embodiments herein.

[0040] Figure 9 is a flowchart depicting a non-limiting example of a method performed by a first network node, according to embodiments herein.

[0041] Figure 10 is a flowchart depicting a non-limiting example of a method performed by a second network node, according to embodiments herein.

[0042] Figure 11 is a flowchart depicting a non-limiting example of signalling in a communications network, according to embodiments herein.

[0043] Figure 12 is a flowchart depicting another non-limiting example of signalling in a communications network, according to embodiments herein.

[0044] Figure 13 is a schematic block diagram illustrating an embodiment of a first network node, according to embodiments herein.

[0045] Figure 14 is a schematic block diagram illustrating an embodiments of a second network node, according to embodiments herein.

[0046] Figure 15 is a schematic block diagram illustrating an embodiments of a third network node, according to embodiments herein.

[0047] Figure 16 is a schematic block diagram illustrating an embodiments of a device, according to embodiments herein. Figure 17 is a flowchart depicting a method in a first network node, according to embodiments herein.

[0048] Figure 18 is a flowchart depicting a method in a second network node, according to embodiments herein.

[0049] Figure 19 is a flowchart depicting a method in a third network node, according to embodiments herein.

[0050] Figure 20 is a flowchart depicting a method in a device, according to embodiments herein. Figure 21 is a schematic block diagram illustrating an example of a communication system 2100 in accordance with some embodiments.

[0051] Figure 22 is a schematic block diagram illustrating an example of a UE 2200 in accordance with some embodiments.

[0052] Figure 23 is a schematic block diagram illustrating an example of a network node 2300 in accordance with some embodiments.

[0053] Figure 24 is a block diagram illustrating an example of a virtualization environment 2400 in which functions implemented by some embodiments may be virtualized.

[0054] DETAILED DESCRIPTION

[0055] As part of the development of embodiments herein, one or more challenges with the existing technology will first be identified and discussed.

[0056] Currently, in case LTM procedures are triggered based on L3 measurements, since the source gNB-Dll may be understood to not be aware of any L3 measurements which may be typically sent by the UE to the gNB-CU, the source gNB-DU has no means to trigger any procedure related to LTM, e.g., LTM cell switch or early synchronization procedures, and this may be understood to mean that LTM will not work at all.

[0057] Certain aspects of the present disclosure and their embodiments may provide solutions to these or other challenges. Embodiments herein may be generally understood relate to network signalling to perform LTM procedures based on L3 measurements.

[0058] In some examples of embodiments herein, in the case of LTM procedures triggered based on L3 measurements, the source gNB may be informed about what LTM procedure may need to trigger. This basically may be done according to two main options. According to one option, the source gNB-CU, upon receiving an L3 measurement report from the UE, may forward the received L3 measurement report to the source gNB-DU. In this case, the source gNB-DU may analyze the received L3 measurement report and decide itself whether to trigger one or more procedures related to LTM. According to another option, the source gNB-CU, upon receiving an L3 measurement report from the UE, may send an indication to the source gNB-DU about one or more procedures related to LTM to be triggered.

[0059] The gNB-DU may indicate to the gNB-CU the supporting of L3 measurement triggering by gNB-CU. It may provide feedback when the LTM may be triggered by gNB-CU.

[0060] Some of the embodiments contemplated will now be described more fully hereinafter with reference to the accompanying drawings, in which examples are shown. In this section, the embodiments herein will be illustrated in more detail by a number of exemplary embodiments. Other embodiments, however, are contained within the scope of the subject matter disclosed herein. The disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art. It should be noted that the exemplary embodiments herein are not mutually exclusive. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments.

[0061] Figure 1 depicts a non-limiting example of a communications network 100. The communications network 100 may be sometimes also referred to as a wireless communications network, wireless communications system, cellular radio system, or cellular network, in which embodiments herein may be implemented. The communications network 100 may be a 5G system, 5G network, or Next Gen System. In other examples, the communications network 100 may be a newer system, e.g., 6G, with similar functionality. The communications network 100 may, e.g., in addition, support other technologies such as, for example, Long-Term Evolution (LTE), e.g. LTE-M, LTE Frequency Division Duplex (FDD), LTE Time Division Duplex (TDD), LTE Half-Duplex Frequency Division Duplex (HD-FDD), LTE operating in an unlicensed band, such as LTE Licensed-Assisted Access (LAA), enhanced eLAA (eLAA), further enhanced LAA (feLAA) and / or MulteFire. Yet in other examples, the communications network 100 may further support other technologies such as, for example Wideband Code Division Multiple Access (WCDMA), Universal Terrestrial Radio Access (UTRA) TDD, Global System for Mobile communications (GSM) network, GSM / Enhanced Data Rates for GSM Evolution (EDGE) Radio Access Network (GERAN) network, Ultra-Mobile Broadband (UMB), EDGE network, network comprising any combination of Radio Access Technologies (RATs) such as e.g. Multi-Standard Radio (MSR) base stations, multi-RAT base stations etc., any 3rd Generation Partnership Project (3GPP) cellular network, WiFi networks, Worldwide Interoperability for Microwave Access (WiMax), or any cellular network or system. The communications network 100 may support Machine Type Communication (MTC), eMTC, Internet of Things (loT) and / or NarrowBand Internet of Things (NB-loT). Thus, although terminology from 5G / NR and LTE may be used in this disclosure to exemplify embodiments herein, this should not be seen as limiting the scope of the embodiments herein to only the aforementioned system.

[0062] The communications network 100 may comprise a plurality of network nodes, whereof a first network node 111 , a second first network node 111, a third network node 113, and a fourth network node 114 comprised in the communications network 100 are depicted in the non-limiting example of Figure 1 . Any of the first network node 111 , the second network node 112, the third network node 113, and the fourth network node 114 may be a radio network node. That is, a transmission point such as a radio base station, for example a gNB, or any other network node with similar features capable of serving a user equipment, such as a wireless device or a machine type communication device, in the communications network 100. In some examples, not depicted in Figure 1 , any of the first network node 111 , the second network node 112, the third network node 113, and the fourth network node 114 may be a distributed node, and may partially perform its functions in collaboration with a virtual node in a cloud 115. Any of the first network node 111 , the second network node 112, the third network node 113, and the fourth network node 114 may be directly connected to one or more core networks. In the non-limiting example of Figure 1 b), the first network node 111 , and the third network node 113 are depicted as network nodes in the cloud 115.

[0063] In particular examples, any of the first network node 111 , the second network node 112, the third network node 113, and the fourth network node 114 may be a gNB.

[0064] In some examples, any of the first network node 111 , the second network node 112, the third network node 113, and the fourth network node 114 may be co-localized or be the same node. In typical examples, the first network node 111 and the second network node 112 may be comprised in a same node and the third network node 113, and the fourth network node 114 may be comprised in another same node.

[0065] In some examples, each of second network node 112, and the fourth network node 114 may be a base station such as e.g. gNB, or, e.g. in case of a distributed CU / Dll RAN architecture, a distributed unit, sometimes known as either gNB-Dll or DU. Hence the second network node 112 may correspond to a source DU, S-DU, sometimes also known as serving DU, and the fourth network node 114 may correspond to a target DU. The target DU may be sometimes called neighbour DU or candidate DU, C-DU.

[0066] The second network node 112, and the fourth network node 114 may be both connected to a first network node 111 , sometimes also referred to as serving network node. In some scenarios, the second network node 112 and the fourth network node 114 may be connected to different first network nodes 111.

[0067] The second network node 112, and the fourth network node 114 may be both connected to a third network node 113, sometimes also referred to as serving network node. In some scenarios the second network node 112 and the fourth network node 114 may be connected to different third network nodes 113.

[0068] The first network node 111 and the third network node 113 may in some examples be the same network node.

[0069] Further, either or both of the first network node 111 and the third network node 113 may, e.g. in case of a distributed CU / DU RAN architecture, be a central unit, CU, sometimes referred to as the serving CU, known as either a gNB-Cll, CU, gNB-CU-CP or gNB-CU-UP, or a core network node such as a User Plane Function (UPF) or an Access and Mobility management Function (AMF).

[0070] Any of the first network node 111 , the second network node 112, the third network node 113, and the fourth network node 114 may cover a geographical area, which in some embodiments may be divided into cell areas, wherein each cell area may be served by a radio network node, although, one radio network node may serve one or several cells. In the example of Figure 1 , the second network node 112 serves a first cell 121 , and the fourth network nodes 114 serves one or more second cells 122. It will be understood that more cells may be comprised in the communications network 100.

[0071] In the context of a mobility procedure, such as an LTM procedure, such as an LTM cell switch procedure, for a UE such as the device 130 described below, the second network node

[0072] 112, sometimes also referred to as the serving network node, may control a source cell such as the first cell 121 , sometimes called serving cell or Special Cell (SpCell). The fourth network node 114 may control a target cell such as one of the one or more second cells 122, sometimes called target cell, neighbour cell, candidate cell or LTM candidate cell. The second network node 112 and the fourth network node 114 may be the same network node.

[0073] Any of the first network node 111 , the second network node 112, the third network node

[0074] 113, and the fourth network node 114 may be of different classes, such as, e.g., macro base station, home base station or pico base station, based on transmission power and thereby also cell size. In some examples, any of the first network node 111 , the second network node 112, the third network node 113, and the fourth network node 114 may serve receiving nodes with serving beams. The communications network 100 may support one or several communication technologies, and the name of any of the first network node 111 , the second network node 112, the third network node 113, and the fourth network node 114 may depend on the technology and terminology used.

[0075] A plurality of devices may be located in any of the communications network 100, whereof a device 130 is depicted in the non-limiting examples of Figure 1. The device 130 comprised in the communications network 100 may be a wireless communication device such as a User Equipment (UE), e.g., 5G UE or nUE, which may also be known as e.g., mobile terminal, wireless device, wireless terminal and / or mobile station, a mobile telephone, cellular telephone, cellular smartphone or laptop with wireless capability, just to mention some further examples. The device 130 may be, for example, portable, pocket-storable, hand-held, computer- comprised, or a vehicle-mounted mobile device, enabled to communicate voice and / or data, via the RAN, with another entity, such as a server, a laptop, a Personal Digital Assistant (PDA), or a tablet, Machine-to-Machine (M2M) device, a headset, goggles, a sensor, loT device, NB-loT device, device equipped with a wireless interface, such as a printer or a file storage device, modem, or any other radio network unit capable of communicating over a radio link in a communications system. The device 130 comprised in the communications network 100 may be enabled to communicate wirelessly in the communications network 100. The communication may be performed e.g., via a RAN, and possibly the one or more core networks, which may be comprised within the communications network 100.

[0076] The first network node 111 may be configured to communicate within the communications network 100 with the second network node 112 over a first link 141 , e.g., a radio link or a wired link. The device 130 may be configured to communicate within the communications network 100 with the second network node 112 over a second link 142, e.g., a radio link. The third network node 113 may be configured to communicate within the communications network 100 with the fourth network node 114 over a third link 143, e.g., a radio link or a wired link. The device 130 may be configured to communicate within the wireless communications network 100 with the fourth network node 114 over a fourth link 144, e.g., a radio link. The first network node 111 may be configured to communicate within the communications network 100 with the fourth network node 114 over a fifth link 145, e.g., a radio link or a wired link. The third network node 113 may be configured to communicate within the communications network 100 with the second network node 112 over a sixth link 146, e.g., a radio link or a wired link.

[0077] The thick arrow in Figure 1 indicates a mobility of the device 130 from the first cell 121 to one of the one or more second cells 122.

[0078] Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and / or is implied from the context in which it is used. All references to a / an / the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and / or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following description.

[0079] In general, the usage of “first”, “second”, “third”, “fourth”, “fifth” and / or “sixth” herein may be understood to be an arbitrary way to denote different elements or entities, and may be understood to not confer a cumulative or chronological character to the nouns they modify, unless otherwise noted, based on context.

[0080] Several embodiments are comprised herein. It should be noted that the examples herein are not mutually exclusive. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments.

[0081] More specifically, the following are embodiments related to a first network node, such as the first network node 111 , e.g., a gNB, a second network node, such as the second network node 112, e.g., a gNB, a third network node, such as the third source network node 113, e.g., a gNB, and a device, such as the device 130.

[0082] The terms source and target may be understood within the context of a mobility procedure.

[0083] Some embodiments herein will now be further described with some non-limiting examples, which may be combined with the embodiments just described. Any of the features described in the text below may be individually combined with any of the embodiments just described.

[0084] In the following description, any reference to a / the UE, or simply “UE” may be understood to equally refer the device 130; any reference to a / the first network node, a / the CU, a / the gNB CU, a / the serving gNB-Cll, a / the controlling gNB-Cll, a / the serving gNB-CU-CP, a / the CLI-CP may be understood to equally refer to the first network node 111; any reference to a / the second network node, a / the DU, a / the gNB DU, a / the serving gNB-DU, a / the source DU, a / the CU-UP may be understood to equally refer to any of the second network node 112; any reference to a / the target CU, a / the target gNB CU, a / the serving gNB-CU-UP, a / the CU-UP, a / the candidate CU may be understood to equally refer to the third network node 113; any reference to a / the target DU, a / the target gNB DU, a / the candidate DU may be understood to equally refer to the fourth network node 114.

[0085] Initial description

[0086] The present disclosure refers to the term “L1 / L2 based inter-cell mobility” as used in the Work Item Description in 3GPP, though it may interchangeably also use the terms L1 / L2 mobility, L1-mobility, L1 based mobility, L1 / L2-centric inter-cell mobility, L1 / L2 inter-cell mobility L1 / L2-Triggered Mobility, Lower-layer triggered Mobility or LTM. The basic principle may be understood to be that the UE may normally receive a lower layer signalling from the network indicating to the UE a change, or switch or activation, of its serving cell, e.g., change of PCell, from a source to a target PCell, wherein a lower layer signalling may be understood to be a message / signalling of a lower layer protocol, which sometimes may be referred to as an L1 / L2 inter-cell mobility execution command or LTM cell switch command. The change of serving cell, e.g., change of PCell, may also lead to a change in Scell(s) for the same cell group e.g., in case the command may trigger the UE to change to another cell group configuration of the same type, e.g., another Master Cell Group (MCG) configuration. Before the UE receives the LTM cell switch command, the UE may be configured by the network with one or more LTM candidate cell configurations, e.g., reception of an RRC Reconfiguration message, with at least one LTM candidate cell configuration. An LTM candidate cell configuration may include parameters in the IE CellGroupConfig for an LTM candidate cell and / or an embedded RRC Reconfiguration for an LTM candidate cell.

[0087] The term LTM cell switch procedure may be understood to refer to the process of a UE switching, or changing, its cell from a source cell to a target cell, which may be called here an LTM candidate cell or a neighbour cell, using L1 / L2-triggered mobility (LTM). In the context of L1 / L2-triggered mobility (LTM), an LTM cell switch procedure may sometimes also be known as L1 / L2 based inter-cell mobility execution, LTM execution, dynamic switch, LTM switch, (LTM) cell switch, (LTM) serving cell change or (LTM) cell change. In the context of embodiments herein, switching to the LTM candidate cell configuration may comprise the UE considering that an LTM candidate cell becomes its new special cell (SpCell) e.g., PCell in case of LTM being configured for an MCG and / or PSCell in case of LTM being configured for a Secondary Cell Group (SCG); or, changing its SpCell from the current PCell to an LTM candidate cell.

[0088] Even if the term switch or change of cells is used, that may comprise a switch or change of a whole cell group configuration, which may include a change in the SpCell, e.g., change of PCell, or change of PSCell, and a change in SCells of the cell group, e.g., addition, modification and / or release of one or more SCells.

[0089] An LTM cell switch procedure may be triggered in the UE by reception of an LTM cell switch command, or alternatively, triggered by some other event, such as a condition, e.g., a triggering condition used for conditional configuration, such as conditional handover, being fulfilled, as a result of recovery from radio link failure or handover failure.

[0090] The current disclosure may refer to an LTM candidate cell, which may be a cell the UE may be configured with when configured with L1 / L2-triggered mobility. That is, a cell the UE may move to in an LTM cell switch procedure. Such cells may also be called candidate cell(s), candidates, mobility candidates, non-serving cells, additional cells, target candidate cell, target candidate, etc. An LTM candidate cell may be understood to be a cell the UE may perform measurements on, e.g., Channel State Information (CSI) measurements, so that the UE may report these measurements and the network may take an educated decision on which beam, e.g., TCI state, and / or cell the UE may have to be switched to. An LTM candidate cell may be a candidate to be a target PCell or PSCell, or an SCell of a cell group, e.g., MCG SCell or an SCG SCell.

[0091] The disclosure herein may refer to at least one LTM candidate cell configuration and that the UE may have received at least one LTM candidate cell configuration. This may also sometimes be referred to as a configuration of a LTM candidate cell, which may be an RRC configuration, such as encapsulated in an RRC Reconfiguration message, that the UE may receive when being configured with L1 / L2-Triggered Mobility. An LTM candidate cell configuration may comprise the configuration which the UE may need to start to operate accordingly when it may perform an LTM cell switch procedure to that LTM candidate cell e.g., upon reception of the LTM cell switch command indicating the UE to perform an LTM cell switch procedure to that LTM candidate cell, which may become the target cell and the current (new) SpCell, or an SCell in a serving frequency. The LTM candidate cell configuration may comprise parameters of a serving cell, or multiple serving cells, such as a cell group, comprising one or more of the groups of parameters, such as an RRCReconfiguration message an IE CellGroupConfig or an IE SpCellConfig, or the IE SCellConfig, in the case of a Secondary Cell. An LTM candidate cell configuration may in one example comprise one or more of: i) the PCell configuration and one or more SCell configuration(s) of a Master Cell Group (MCG); i) the PSCell configuration and one or more SCell configuration(s) of a secondary Cell Group (SCG). The terms (LTM) candidate configuration, LTM configuration, (LTM) candidate target cell configuration, (LTM) target candidate (cell) configuration may be used interchangeably when referring to LTM candidate cell configuration. An LTM candidate cell configuration may be associated with an identifier which may be used in the signalling when referring to a certain LTM candidate cell configuration, such as when the UE may receive the LTM candidate cell configuration and when the UE may receive an LTM cell switch command indicating the UE to perform an LTM cell switch procedure to that LTM candidate cell. This identifier may sometimes be known as the LTM candidate cell configuration identity or LTM candidate configuration index or similar.

[0092] The actual LTM candidate cell configuration and its exact content and / or structure of this IE and / or embedded message may be called an RRC model for the candidate configuration, or simply RRC model. An LTM candidate cell configuration may comprise the configuration which the UE may need to operate accordingly when it may perform, or execute, L1 / L2 based intercell mobility execution to a LTM candidate cell, upon reception of the lower layer signalling, e.g., MAC Control Element (MAC CE) indicating an L1 / L2 based inter-cell mobility to a LTM candidate cell, which may become the target cell and the current (new) PCell, or an SCell in a serving frequency, or upon reception of the lower layer signalling, e.g., MAC CE, indicating an L1 / L2 based inter-cell mobility to an LTM candidate cell configuration indicated with a candidate configuration index, sometimes also denoted candidate configuration Identity or Identifier (ID). The UE may be configured with multiple LTM candidate cell configurations, so a Candidate DU may generate and send to the CU multiple configuration(s). The actual LTM candidate cell configuration the UE may receive during the LTM configuration may be a delta signalling to be applied on top of a reference configuration, so that the actual configuration the UE may have to use in the candidate cell upon LTM cell switch may be the combination of the LTM candidate cell configuration and the reference configuration, e.g., separately signalled by the network to the UE.

[0093] The disclosure herein may refer to “LTM related procedure” or “LTM procedure” and this term may be used to identify all the procedure that may be executed within the context of LTM, such as an LTM configuration procedure, that is, the UE may be configured for LTM including for example LTM candidate cell configurations, an LTM cell switch procedure, an early UL synchronization procedure, or an early DL synchronization procedure.

[0094] Embodiments of a method, performed by a first network node, such as the first network node 111 , will now be described with reference to the flowchart depicted in Figure 2. The method is for handling mobility. The first network node 111 operates in a communications network, such as the communications network 100.

[0095] The method may be understood to be computer-implemented.

[0096] The mobility may be L1 / L2 Triggered Mobility (LTM) for the device 130, e.g., a UE.

[0097] In some embodiments, the communications network 100 may support, or operate in, New Radio (NR).

[0098] Several embodiments are comprised herein. The method may comprise one or more of the following actions. In particular examples, the method may comprise Action 205. In some embodiments, all the actions may be performed. One or more embodiments may be combined, where applicable. It should be noted that the examples herein are not mutually exclusive. One or more embodiments may be combined, where applicable. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments. All possible combinations are not described to simplify the description. A non-limiting example of the method performed by the first network node 111 is depicted in Figure 2. In Figure 2 optional actions in some embodiments may be represented with dashed lines. In some embodiments, the actions may be performed in a different order than that depicted Figure 2.

[0099] Action 201

[0100] In this Action 201 , the first network node 111 may receive a message, which may be referred to herein as a previous message.

[0101] The receiving in this Action 201 may be from the device 130. The first network node 111 may be, e.g, a serving gNB-CU, a serving gNB-CU-CP.

[0102] The previous message may indicate one or more L3 measurements.

[0103] The previous message may be, e.g., a report, e.g., an L3 measurements report.

[0104] Action 202

[0105] In this Action 202, the first network node 111 may determine whether or not to initiate one or more LTM procedures. That is, whether or not to initiate the LTM.

[0106] Determining may be understood as calculating, deriving, dividing or similar.

[0107] The determining in this Action 202 may be based on the received previous message. In some examples, the determining in this Action 202 may be based on one or more of the following options. According to one option, the determining in this Action 202 may be based on failing to receive L1 measurements.

[0108] According to another option, the determining in this Action 202 may be based on a frequency of a carrier used.

[0109] According to yet another option, the determining in this Action 202 may be based on one or more conditions.

[0110] According to another option, the determining in this Action 202 may be based on at least one property of the L3 measurements fulfilling a first condition. For instance, the first network node 111 may determine to send a notification, or first indication, initiate one or more LTM procedures only if at least one property of the L3 measurements fulfil a condition, such as the RSRP, or the Reference Signal Received Quality (RSRQ), or the Signal to Interference plus Noise Ratio (SINR) of a cell reported in the L3 measurements, e.g., the best cell, is above a certain threshold, or below a certain threshold, or within two thresholds, or the RSRP, or the RSRP, or the SINR, of a reference signal reported in the L3 measurements, e.g., the best SSB, is above a certain threshold, or below a certain threshold, or within two thresholds. In another case, the condition may be relate to the availability, or absence, or aging, or accuracy, of specific L1 measurements, e.g., the notification to initiate LTM cell switch based on L3 measurements may be sent if L1-SINR measurement is not available, or is considered too old.

[0111] According to yet another option, the determining in this Action 202 may be based on availability of specific L1 measurements.

[0112] According to another option, the determining in this Action 202 may be based on availability of the specific L1 measurements for one cell. The condition may relate to the availability, or absence, or absence, or accuracy, of certain L1 measurements for cell, or for reference signals.

[0113] The first network node 111 may, according to this Action 202, decide to trigger an LTM cell switch procedure for the device 130 towards an LTM candidate cell. The first network node 111 may at this point perform LTM configuration of the device 130, such as configuring the indicated neighboring cell as an LTM candidate cell for the device 130.

[0114] In one example, the first network node 111 may determine whether trigger of LTM cell switch from the second network node 112 based on L3 measurements is applicable or not, based on information previously received from the second network node 112 and / or candidate cells for LTM execution, e.g., according to at least one of the UL Freqinfo and / or UL Freqinfo and / or NR Freq Info lEs of the Served Cell Information IE contained in the Served Cells To Add Item IE within a GNB-DU CONFIGURATION UPDATE F1AP or an F1 SETUP REQUEST message. In one example, if the serving cell controlled by the second network node 112 is operating at a carrier frequency in FR2, then LTM cell switch from the second network node 112 based on L3 measurements may not be applicable. In another example, if the candidate cell towards which the second network node 112 would trigger LTM cell switch execution is operating in FR2, then LTM cell switch from the second network node 112 based on L3 measurements may not be applicable. In yet another example, if both the source cell served by the second network node 112 and the candidate cell towards which the second network node 112 would trigger LTM cell switch execution is operating in FR2, then LTM cell switch from the second network node 112 based on L3 measurements may not be applicable.

[0115] Action 203

[0116] In this Action 203, the first network node 111 may send a second indication.

[0117] The sending in this Action 203 may be to the third network node 113 operating in the communications network 100. The third network node 113 may be a serving gNB-CU-UP.

[0118] The second indication may request whether or not the one or more LTM procedures, e.g., LTM cell switch to one or more second cells 122, may be possible e.g., based on at least one of L1 and L3 measurements. The one or more second cells 122 may be served by the fourth network node 114 managed by the third network node 113.

[0119] In one example, the first network node 111 , e.g., the serving gNB-CU, may request the third network node 113, e.g., a candidate gNB-CU, that is, a gNB-CU controlling at least one candidate LTM cell, to provide, e.g., as part of LTM configuration, an indication, referred to herein as third indication, indicating whether LTM cell switch execution towards any, or all, or a certain LTM candidate cell served by the third network node 113, or the fourth network node 114, may be performed according to one of the following criteria: only based on L1 measurements, only based on L3 measurements, based on either L1 measurement or L3 measurements, based on L1 and L3 measurements. For example, the request may be sent in a new IE, e.g., an “LTM cell switch execution measurement type" IE or alike, in an HANDOVER REQUEST XnAP message.

[0120] In one example, the first network node 111 may send a message to a fourth network node 114 or a third network node 113, e.g., a HANDOVER REQUEST or a LTM CONFIGURATION REQUEST message, the message comprising the second indication, e.g., a flag, to indicate the fourth network node 114, or the third network node 113, that LTM cell switch execution towards a candidate cell can, or shall, or should, or may, be initiated based on L3 measurements. In one option, the second indication may be per source cell, or per LTM cell ID. In another option, the second indication may be per gNB-DU. In another option, the second indication may be per LTM configuration ID.

[0121] The second indication may be e.g., a Bearer Context Modification Request. The first network node 111 may, according to this Action 203, transmit an E1AP message, e.g., BEARER CONTEXT MODIFICATION REQUEST, to indicate to the third network node 113 that an LTM procedure needs to be triggered to the source DU.

[0122] Action 204

[0123] In this Action 204, the first network node 111 may receive a third indication.

[0124] The receiving in this Action 204 may be from the third network node 113.

[0125] The receiving in this Action 204 may be responsive to the sent second indication.

[0126] The third indication may indicate whether or not (the) one or more LTM procedures, e.g., LTM cell switch to one or more second cells 122, may be possible, e.g., based on at least one of L1 and L3 measurements.

[0127] In one example, the first network node 111 , e.g., the serving gNB-CU, may receive from the third network node 113, e.g., the candidate gNB-CU, that is, a gNB-CU controlling at least one candidate LTM cell, the third indication, indicating that for all, or a certain LTM candidate cell served by the third network node 113, or the fourth network node 114, LTM cell switch execution may be performed according to one of the following criteria: only based on L1 measurements, only based on L3 measurements, based on either L1 measurement or L3 measurements, based on L1 and L3 measurements. For example, the third indication may be received in a new IE, e.g., an “LTM cell switch execution measurement type" IE or alike, in an HANDOVER REQUEST ACKNOWLEDGE XnAP message.

[0128] The third indication may be e.g., a Bearer Context Modification Response. The third network node 113 according to Action 402, may send a BEARER CONTEXT MODIFICATION RESPONSE to acknowledge that it may receive the request message.

[0129] Action 205

[0130] In this Action 205, the first network node 111 sends, e.g., transmits, a first message. The message may include an indication about an LTM procedure.

[0131] Sending is to the second network node 112 operating in the communications network 100. The first message comprises a first indication, e.g., a first indicator. The first indication indicates the one or more LTM procedures, e.g., an L1 / L2-Triggered Mobility (LTM), for the device 130 operating in the communications network 100. The first message indicates one or more target cells or beams. The first indication may be a request to initiate an LTM procedure.

[0132] The LTM procedure may be an LTM cell switch procedure. In one example, the first message may include an indicated LTM candidate cell. The first message may in one example include a measurement received from the UE.

[0133] The LTM procedure may be an early synchronization procedure, such as an early DL sync procedure, candidate TCI state activation procedure, early UL sync procedure or an TA acquisition procedure. That the first message indicates the one or more target cells or beams may be understood to mean that the first message may indicate one or more target cells, one or more target beams, or that the first message may indicate one or more target cells and target beams. The one or more target cells may be e.g., the one of the one or more second cells 122.

[0134] The sending in Action 205 of the first message may be based on a result of the determination in Action 202.

[0135] In some examples, one or more of the following may apply: a) the first network node 111 may serve the device 130, b) the second network node 112 may serve the device 130, c) the first network node 111 may be a Central Unit (CU), the second network node 112 may be a Distributed Unit (DU), d) the LTM may comprise one or more LTM procedures, e) the one or more LTM procedures may comprise one or more of: i) an LTM cell switch procedure from the first cell 121 to the second cell 122, ii) an early synchronization procedure, iii) a candidate Transmission Configuration Indication (TCI) procedure, iv) an early uplink synchronization procedure, and v) a Timing Advance (TA) acquisition procedure, f) the first message may be an F1AP message, g) the first message may be Class 1 UE associated signalling or a Class 2 UE associated signalling, h) the first message may indicate one or more Layer 3 (L3) measurements performed by the device 130, i) the first message may request one or more Layer 1 (L1) measurements performed by the device 130, j) the first message may indicate a change in a triggering LTM cell switch decision for one or more candidate cells, k) the first indication may be one of implicit and explicit, and I) the first indication may be per candidate cell or for all candidate cells.

[0136] In some examples, one of the following may apply: a) the first message may indicate whether or not the one or more LTM procedures may be possible, b) the first message may indicate a request to initiate the one or more LTM procedures, c) the first message may indicate a preference to initiate the one or more LTM procedures, d) the first message may indicate a preference to initiate the one or more LTM procedures based on L3 measurements, e) the first message may indicate a preference to initiate the one or more LTM procedures based on L1 measurements, f) the first message may be a MEASUREMENT NOTIFICATION, g) the first message may be a UE CONTEXT SETUP REQUEST, h) the first message may be a UE CONTEXT MODIFICATION REQUEST, i) the first message may be a CU-DU Cell Switch Notification, and j) the first message may be a MEASUREMENT TRANSFER message.

[0137] The sending in Action 205 of the first message may be based on the received previous message. The first network node 111 may decide to trigger an LTM procedure based on the received L3 measurements from the device 130 and may send the first message to the second network node 112, e.g., in one F1AP message, by indicating whether the second network node 112 may have to trigger an LTM procedure to the device 130. Various options are presented below, and it may be understood that combinations of multiple options are not precluded.

[0138] In one option, the indicator, that is, the first indication, may be an enumerated value, corresponding to “0” or “1” or “trigger LTM procedure” or “not trigger LTM procedure” for each LTM candidate cell configured by the second network node 112, e.g., a gNB-Dll.

[0139] In another option, the indicator, that is, the first indication, may be lower layer measurements.

[0140] In another option, the first indication for the second network node 112 to initiate LTM procedure may be determined based on the message being received. That is, the first indication may be in this option, an implicit indication.

[0141] As stated earlier, the first message may be an F1AP message. The first message may be a UE CONTEXT MODIFICATION REQUEST. In one option, the F1AP message may be a Class 1 UE associated signalling, e.g., UE CONTEXT MODIFICATION REQUEST. An example of such a first message as implementation in the 3GPP F1AP specification, TS 38.473 v18.2.0, may be as follows.

[0142] Example A

[0143] 9.2.2.7 UE CONTEXT MODIFICATION REQUEST

[0144] This message may be sent by the first network node 111 , e.g., the gNB-Cll, to provide UE Context information changes to the second network node 112, e.g., the gNB-Dll.

[0145] Direction: gNB-Cll gNB-Dll

[0146] In the following example, the UE CONTEXT SETUP REQUEST F1AP message may be extended to inform the second network node 112, e.g., the gNB-DU, whether LTM cell switch command to the device 130, e.g., the UE, may be based on L3 measurements.

[0147] Example B 9.2.2.7 UE CONTEXT MODIFICATION REQUEST

[0148] This message may be sent by the first network node 111 , e.g., the gNB-Cll to provide UE Context information changes to the second network node 112, e.g., the gNB-Dll.

[0149] Direction: gNB-Cll gNB-Dll

[0150] Example C

[0151] 8.3.4 UE Context Modification (gNB-CU initiated)

[0152] 8.3.4.1 General

[0153] The purpose of the UE Context Modification procedure may be understood to be to modify the established UE Context, e.g., establishing, modifying and releasing radio resources or sidelink resources. This procedure may also be used to command the second network node 112, e.g., the gNB-DU, to stop data transmission for the UE for mobility, see TS 38.401 [4], The procedure may use UE-associated signalling.

[0154] 8.3.4.2 Successful Operation

[0155] The UE CONTEXT MODIFICATION REQUEST message may be initiated by the first network node 111, e.g., a gNB-CU.

[0156] Text omitted.

[0157] If the Measurement Information IE is included in the Measurement Notification List IE in the UE CONTEXT MODIFICATION REQUEST message and set to true, the second network node 112, e.g., the gNB-DU, may have to, if supported, indicate in the UE CONTEXT MODIFICATION RESPONSE the cell indicated by the included Cell ID IE towards which it will initiate a cell switch command. As stated earlier, the first message may be a Class 2 UE associated signalling. In another option, the F1AP message may be a Class 2 UE associated signalling, e.g., CU-DU Cell Switch Notification. The first message may be a CU-DU Cell Switch Notification.

[0158] As stated earlier, the first message may request one or more L1 measurements performed by the device 130. In one option the first network node 111 , e.g., the CU, may signal to the second network node 112, e.g., the DU, to ask for L1 measurements, e.g., if the CU is not certain what to do based on the L3 measurements.

[0159] As stated above, the first message may indicate a preference to initiate the one or more LTM procedures based on L3 measurements. In one option the first network node 111, e.g., the CU, may notify the second network node 112, e.g., the DU, a preference for a L3 Handover based on the received measurements.

[0160] In another option, the F1AP message may be a new Class 2 UE associated signalling.

[0161] In another option based on measurements, the first network node 111 , e.g., the CU, may decide to immediately trigger an L3 Handover (HO) to another DU and at the same time may notify the second network node 112, e.g., the serving DU. In one option, the F1AP message to the serving DU may be Class 1 UE associated signaling, e.g., UE CONTEXT MODIFICATION REQUEST.

[0162] In another example the first network node 111, e.g., the CU, may indicate one target cell to which the LTM procedure may have to be triggered by the second network node 112, e.g., the DU. In one example, the first indication of one cell may be a cell identifier. In another example, the first indication of one cell may be an indication of an LTM candidate cell configuration.

[0163] In another example, the first network node 111 , e.g., the CU, may indicate a beam in a target cell to which the LTM procedure may have to be triggered by the second network node 112, e.g., the DU. In one example, the first indication of a beam may be an indication of a TCI state. In another example, the first indication of a beam may be associated with L1 or L3 measurements, e.g., a measurement value for a specific beam, e.g., associated with a certain Synchronization Signal Block (SSB) or CSI-Reference Signal (RS) based beam.

[0164] In another example, the first network node 111 , e.g., the CU, may indicate a TA to be used by the device 130 in a target cell, e.g., to perform an LTM cell switch without random access.

[0165] In another example, the first network node 111 , e.g., the CU, may indicate more than one cell that may be the best candidates for the second network node 112, e.g., the DU, and let the second network node 112, e.g., the DU, decide towards which one to trigger LTM cell switch based on L1 measurements.

[0166] In another option, the first indication may not be a 1 -bit indicator but it may include more information about whether one or more LTM procedures may have to be executed. For instance, the first indication may include one or more of the following: i) an indication of whether an early DL synchronization procedure, also called TCI state activation procedure, may have to be triggered, ii) an indication of whether an early UL synchronization procedure, also called TA acquisition procedure, may have to be triggered, iii) an indication of whether an LTM cell switch procedure may have to be triggered, iv) one or more LTM candidate identifiers to which the early DL synchronization, and / or the early UL synchronization, and / or LTM cell switch procedure may have to be executed.

[0167] As stated earlier, the first message may indicate one or more L3 measurements performed by the device 130. In some examples, the first network node 111 may decide that an LTM procedure based on the received L3 measurements from the device 130, e.g., the UE, may have to be triggered but, instead of indicating to the second network node 112 to trigger one or more LTM procedure, it may simply send the received L3 measurements, e.g., in one F1AP message, to the second network node 112. Various options are presented below, and it should be understood that combinations of multiple options are not precluded. As stated earlier, the first message may indicate a request to initiate the one or more LTM procedures. The first indication may be per candidate cell or for all candidate cells. In one option, together with the L3 measurements there may also be an indicator, where the value may correspond to “0” or “1” or “trigger LTM procedure” or “not trigger LTM procedure” for each LTM candidate cell configured by the second network node 112, e.g., the gNB-DU. In another option, the sending of the L3 measurements may also be an indication for the second network node 112 to initiate LTM procedure. In one option, the F1AP message may be a Class 1 UE associated signalling, e.g., UE CONTEXT MODIFICATION REQUEST. In another option, the F1AP message may be a Class 2 UE associated signalling, e.g., CU-DU Cell Switch Notification. In one option, the first network node 111, e.g., the CU, may signal to the second network node 112, e.g., the DU, to ask for L1 measurements, e.g., if the first network node 111 , e.g., the CU, is not certain what to do based on the L3 measurements. As stated earlier, the first message may indicate a preference to initiate the one or more LTM procedures. In one option, the first network node 111 , e.g., the CU, may notify the second network node 112, e.g., the DU, a preference for an L3 Handover based on the received measurements. In another option, the F1AP message may be a new Class 2 UE associated signalling. In another option, based on measurements the first network node 111, e.g., the CU, may decide to immediately trigger an L3 HO to another DU and at the same time may notify the second network node 112, e.g., the serving DU. In one option, the F1AP message to the second network node 112, e.g., the serving DU, may be Class 1 UE associated signalling, e.g., UE CONTEXT MODIFICATION REQUEST. In another option, the first indication may not be a 1-bit indicator, but it may include more information about whether one or more LTM procedures may have to be executed. For instance, the first indication may include one or more of the following: i) an indication of whether an early DL synchronization procedure, also called TCI state activation procedure, may have to be triggered; ii) an indication of whether an early UL synchronization procedure, also called TA acquisition procedure, may have to be triggered; iii) an indication of whether an LTM cell switch procedure may have to be triggered; iv) one or more LTM candidate identifiers to which the early DL synchronization, and / or the early UL synchronization, and / or LTM cell switch procedure may have to be executed.

[0168] In one example, the first network node 111 may send a notification, or first indication, to the second network node 112, which may result in the second network node 112 initiating an LTM cell switch based on L3 measurements. The L3 measurements may have been received solely by the first network node 111 , or in another option may be included in the notification. In one option, the first network node 111 first may receive the L3 measurements and may send the notification immediately. In another option, the first network node 111 may receive L3 and L1 measurements and may determine to send the notification. In yet another option, the first network node 111 may determine that the notification is to be sent due to not receiving also L1 measurements. In yet another option, the first network node 111 may determine to send the notification depending on the carrier frequency, or carrier frequency range to which L3 measurements, or L1 measurements, may refer to.

[0169] In yet another option, the first network node 111 may first receive the L3 measurements and send the notification based on conditions. As stated earlier, the determining in Action 202 may be based on one or more conditions. According to an option, the determining in Action 202 may be based on at least one property of the L3 measurements fulfilling a first condition. For instance, the notification may be sent only if at least one property of the L3 measurements fulfil a condition, such as the RSRP, or the Reference Signal Received Quality (RSRQ), or the Signal to Interference plus Noise Ratio (SINR) of a cell reported in the L3 measurements, e.g., the best cell, is above a certain threshold, or below a certain threshold, or within two thresholds, or the RSRP, or the RSRP, or the SINR, of a reference signal reported in the L3 measurements, e.g., the best SSB, is above a certain threshold, or below a certain threshold, or within two thresholds. In another case, the condition may be relate to the availability, or absence, or aging, or accuracy, of specific L1 measurements, e.g., the notification to initiate LTM cell switch based on L3 measurements may be sent if L1-SINR measurement is not available, or is considered too old. In another case, the condition may relate to the availability, or absence, or absence, or accuracy, of certain L1 measurements for cell, or for reference signals. The notification, or first indication, may include one or more of the following information: the source cell identity, the identity of the candidate LTM cell towards which the LTM execution may have to be initiated, an UE associated identity, an LTM Cell ID, an LTM Configuration ID.

[0170] As stated earlier, the first message may be a UE CONTEXT SETUP REQUEST. In some examples, the first message may indicate whether or not the one or more LTM procedures may be possible. In one example, the first network node 111 may send a message, that is, the first message, to the second network node 112, e.g., a UE CONTEXT SETUP REQUEST or a UE CONTEXT MODIFICATION REQUEST message, the first message comprising the first indication, e.g., a flag, to indicate to the second network node 112 that LTM cell switch execution can, or shall, or should, or may, be initiated based on L3 measurements. In one option, the first indication may be per source cell, or per LTM cell ID. In another option, the first indication may be per gNB-DU. In another option, the first indication may be per LTM configuration ID.

[0171] In one example, the first network node 111 may send the first message to the second network node 112, e.g., a UE CONTEXT SETUP REQUEST or a UE CONTEXT MODIFICATION REQUEST message, the first message comprising the first indication, e.g., a flag, to indicate to the second network node 112 a preference of the first network node 111 that LTM cell switch is initiated based on L3 measurements. As stated earlier, the first message may indicate a preference to initiate the one or more LTM procedures based on L1 measurements. In one variant, the first indication may indicate a preference of the first network node to initiate LTM cell switch based on L1 measurements.

[0172] As stated earlier, the first message may be a MEASUREMENT TRANSFER message. In one example, if the first network node 111 may send the first message to the second network node 112, e.g., a new MEASUREMENT TRANSFER message, the message comprising L3 measurements as assistance information for the second network node 112, the second network node 112 may determine that LTM cell switch execution can, or shall, or should, or may, be initiated based on L3 measurements. As stated earlier, the first message may indicate a change in a triggering LTM cell switch decision for one or more candidate cells. In another example before the LTM execution, if there is any change in the triggering LTM cell switch decision for some of the candidate cells, the first network node 111 may send an F1 AP message to the second network node 112 informing about the changes. In one example this first message may be a UE Context Modification Request message. In another example, the first network node 111 , as will be described in Action 206, may receive from the second network node 112, e.g., the serving gNB-DU, an indication, e.g., in a second message, that an LTM cell switch command has been sent to the device 130, e.g., a UE. As stated earlier, the first indication may be one of implicit and explicit. In another example, wherein LTM cell switch execution may be applicable based on either L1 measurements or L3 measurements, the first network node 111, e.g., the gNB-CU, may request the second network node 112, e.g., the serving gNB-DU, to provide to the first network node 111 , e.g., the gNB-CU, upon execution of an LTM cell switch command towards the device 130, e.g., the UE, an indication indicating whether LTM cell switch was executed based on L1 measurements or L3 measurements. The request may be explicit, e.g., in an UE CONTEXT MODIFICATION REQUEST F1AP message, or implicit or specified, e.g., in a procedural text of a technical specification. For instance, if the first network node 111, e.g., the gNB-Cll has provided the second network node 112, e.g., the gNB-Dll with L3 measurements, the receiver (gNB-Dll) may have to, if supported, use the L3 measurements for triggering LTM execution, and, according to Action 206, inform the first network node 111, e.g., the gNB-Cll that this was the case. Or, if the first network node 111, e.g., the gNB-Cll has provided the second network node 112, e.g., the gNB-Dll with L3 measurements, the receiver (gNB-Dll) may have to, if supported, according to Action 206, inform the first network node 111 , e.g., the gNB-Cll, whether the LTM cell switch execution was based on L1 measurements or L3 measurements. In another example, the first network node 111 may request, or indicate, to the first / second network node 112, e.g., as part of F1 SETUP RESPONSE or GNB-DU CONFIGURATION UPDATE ACKNOWLEDGE F1AP message, whether L3 measurements will / may be used for LTM cell switch execution. In some examples, the first indication may be a generic indication from the first network node 111 , e.g., the CU to the second network node 112, e.g., the DU, for all LTM candidate cells. In one example, the first network node 111 may send the first indication to the second network node 112, indicating whether LTM cell switch may be executed based solely on L1 measurements, or solely based on L3 measurements, or based on either L1 or L3 measurements, or based on L1 and L3 measurements. In some examples, the first indication may be a per-LTM candidate cell indication, from the first network node 111 , e.g., the CU to the second network node 112, e.g., the DU, on whether LTM execution towards a certain candidate cell may be based on L1 and / or L3 measurements. In one example, the first network node 111 may send a per-LTM candidate cell indication to the second network node 112, indicating whether LTM cell switch towards a specific LTM candidate cell may be executed based solely on L1 measurements, or solely based on L3 measurements, or based on either L1 or L3 measurements, or based on L1 and L3 measurements.

[0173] Further Examples:

[0174] Below implementation in the 3GPP F1AP specification, TS 38.473 v18.2.0, is illustrated for different examples of embodiments herein, particularly for the first message.

[0175] Example D

[0176] 8.3.x Measurement Notification

[0177] 8.3.X.1 General

[0178] The purpose of the Measurement Notification procedure may be understood to be to enable the first network node 111, e.g., the gNB-CU, to inform the second network node 112, e.g., the gNB-DU, about the L3 measurements and enable to trigger the cell switch command to the device 130, e.g., the UE. The procedure may use UE-associated signalling. 8.3.X.2 Successful Operation

[0179] The first network node 111, e.g., the gNB-CU, may initiate the procedure by sending a MEASUREMENT NOTIFICATION message.

[0180] Upon reception of the MEASUREMENT NOTIFICATION message, the second network node 112, e.g., the gNB-DU, may have to, if supported, consider that the first network node 111, e.g., the gNB-CU, has received L3 measurements. A cell switch command may have been sent to the device 130, e.g., the UE, where the target cell may be indicated by the included Cell ID IE.

[0181] If the Measurement Information IE is included in the MEASUREMENT NOTIFICATION message and is set to true, the second network node 112, e.g., the gNB-DU, may have to, if supported, initiate a cell switch command to the target cell indicated by the included Cell ID IE.

[0182] 8.3.X.3 Unsuccessful Operation

[0183] Not applicable.

[0184] 8.3.X.4 Abnormal Conditions

[0185] Not applicable.

[0186] 9.2.2.x MEASUREMENT NOTIFICATION

[0187] This message may be sent by the first network node 111 , e.g., the gNB-CU, to inform the gNB- about the L3 measurements and enable to trigger the cell switch command to the UE. Direction: gNB-CU gNB-DU

[0188] Action 206

[0189] In this Action 206, the first network node 111 may receive a second message.

[0190] The receiving in this Action 206 may be from the second network node 112.

[0191] The receiving in this Action 206 may be responsive to the sent first message.

[0192] The second message may indicate one of: i) whether or not the LTM, e.g., one or more LTM procedures, may have been initiated, e.g., that another indication has been sent to the device 130 instructing the device 130 to perform the LTM, e.g., LTM cell switch, ii) that the LTM, e.g., LTM cell switch, is not allowed, and iii) whether or not L3 measurements are allowed to be used for execution of the LTM, e.g., LTM cell switch.

[0193] In one example, the fourth network node 114, or the third network node 113, may send the second message to the first network node 111 , e.g., a HANDOVER ACKNOWLEDGE or a LTM CONFIGURATION RESPONSE message, the second message comprising an indication, e.g., a flag, to indicate that use of L3 measurements for initiating LTM cell switch is not allowed, or is allowed. In one option, the indication may be per source cell, or per LTM cell ID. In another option, the indication may be per gNB-DU. In another option, the indication is per LTM configuration ID.

[0194] The second message may be, e.g., a UE Context Modification Response.

[0195] The another indication may be, e.g., a MAC CE command.

[0196] An example of the second message as implementation in the 3GPP F1AP specification, TS 38.473 v18.2.0, may be as follows.

[0197] Example E

[0198] In the following example, the DU-CU CELL SWITCH NOTIFICATION F1AP message may be extended to inform the first network node 111 , e.g., the gNB-CU whether LTM cell switch command to the device 130, e.g., the UE was sent based on L1 or L3 measurements.

[0199] 9.2.2.15 DU-CU CELL SWITCH NOTIFICATION

[0200] This message may be sent by the second network node 112, e.g., the gNB-DU, to inform the first network node 111 , e.g., the gNB-CU about the initiation of the cell switch command to the device 130, e.g., the UE.

[0201] Direction: gNB-Dll gNB-Cll

[0202] Example F

[0203] In the following example, the HANDOVER REQUEST ACKNOWLEDGE XnAP message may be extended to indicate which Measurement Type(s) (L1 and / or L3) may be used to trigger LTM Cell Switch towards a certain candidate LTM cell. (Note that, according to RAN4 requirements, for cells operating in FR1, Rel-18 related LTM requirements may be applicable to the case without L1 measurement and reporting of LTM candidate cells, while for cells operating in FR2, Rel-18 related LTM requirements may not be applicable ifL1 measurements for LTM candidate cells are not supported by the UE, or not configured by the network.)

[0204] 9.1.1.2 HANDOVER REQUEST ACKNOWLEDGE

[0205] This message may be sent by the the second network node 112, e.g., the target NG-RAN node, to inform the source first network node 111 , e.g., the NG-RAN node, about the prepared resources at the target. Direction: target NG-RAN node source NG-RAN node.

[0206] In the following example, the HANDOVER REQUEST ACKNOWLEDGE XnAP message may be extended to indicate whether LTM cell switch execution towards a certain LTM candidate cell may be based on L3 measurements or not. 9.1.1.2 HANDOVER REQUEST ACKNOWLEDGE

[0207] This message may be sent by the second network node 112, e.g., the target NG-RAN node, to inform the first network node 111 , e.g., the source NG-RAN node, about the prepared resources at the target.

[0208] Direction: target NG-RAN node source NG-RAN node.

[0209] Embodiments of a computer-implemented method, performed by a second network node, such as the second network node 112, will now be described with reference to the flowchart depicted in Figure 3. The method is for handling mobility. The second network node 112 operates in a communications network, such as the communications network 100. The methods may be for the second network node 112, such as a serving gNB-Dll, to handle LTM for the device 130, e.g., a UE. Several embodiments are comprised herein. The method may comprise one or more of the following actions. In a particular non-limiting example, Action 301 may be performed. In some embodiments, all the actions may be performed. It should be noted that the examples herein are not mutually exclusive. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments. One or more embodiments may be combined, where applicable. All possible combinations are not described to simplify the description. A non-limiting example of the method performed by the second network node 112 is depicted in Figure 3. In Figure 3, optional actions in some embodiments may be represented with dashed lines.

[0210] The detailed description of some of the following corresponds to the same references provided above, in relation to the actions described for the first network node 111 and will thus not be repeated here to simplify the description. For example, the communications network 100 may support, or operate in, New Radio (NR).

[0211] Action 301

[0212] In this Action 301, the second network node 112 receives the first message.

[0213] The receiving in this Action 301 is from the first network node 111 operating in the communications network 100.

[0214] The first message comprises the first indication, e.g., a first indicator. The first indication indicates the one or more LTM procedures, for the device 130 operating in the communications network 100. This Action 301 may comprise receiving, from the first network node 111 , a message with an indication about an LTM procedure for the UE.

[0215] The first message indicates the one or more target cells or beams.

[0216] The first indication may indicate the LTM. The LTM may comprise the one or more LTM procedures.

[0217] In some examples, one or more of the following may apply: a) the first network node 111 may serve the device 130, b) the second network node 112 may serve the device 130, c) the first network node 111 may be a Central Unit, d) the second network node 112 may be a Distributed Unit, e) the one or more LTM procedures may comprise one or more of: i) the LTM cell switch procedure from the first cell 121 to the second cell 122, ii) the early synchronization procedure, iii) the candidate TCI procedure, e.g., a candidate cell or beam TCI procedure, iv) the early uplink synchronization procedure, and v) the TA acquisition procedure, f) the first message may be the F1AP message, g) the first message may be Class 1 UE associated signalling or the Class 2 UE associated signalling, h) the first message may indicate the one or more L3 measurements performed by the device 130, i) the first message may request the one or more L1 measurements performed by the device 130, e.g., received from the device 130, e.g., the UE; j) the first message may indicate the change in the triggering LTM cell switch decision for the one or more candidate cells, k) the first indication may be one of implicit and explicit, and I) the first indication may be per candidate cell or for all candidate cells.

[0218] In an example, the indication received by the first network node 111 may include an explicit indication to trigger an LTM procedure.

[0219] In some examples, one of the following may apply: a) the first message may indicate whether or not the one or more LTM procedures may be possible, b) the first message may indicate the request to initiate the one or more LTM procedures, c) the first message may indicate the preference to initiate the one or more LTM procedures, d) the first message may indicate the preference to initiate the one or more LTM procedures based on L3 measurements, e) the first message may indicate the preference to initiate the one or more LTM procedures based on L1 measurements, f) the first message may be the MEASUREMENT NOTIFICATION, g) the first message may be the UE CONTEXT SETUP REQUEST, h) the first message may be the UE CONTEXT MODIFICATION REQUEST, i) the first message may be the CU-DU Cell Switch Notification, and j) the first message may be the MEASUREMENT TRANSFER message.

[0220] In some embodiments, the method may further, or alternatively, comprise one or more one of the following actions.

[0221] Action 302

[0222] In this Action 302, the second network node 112 may receive a fourth indication.

[0223] The receiving in this Action 302 may be from the third network node 113 or the fourth network node 114 operating in the communications network 100.

[0224] The fourth indication may indicate whether or not the LTM, e.g., LTM cell switch, may be possible.

[0225] The fourth indication may be, e.g, an F1-U message, for example, a DL USER DATA frame.

[0226] In another example, the second network node 112 may receive the indicator, that is, the fourth indication, from the third network node 113 to indicate that an LTM cell switch may be triggered to the UE, via an F1-U message, for example, DL USER DATA frame.

[0227] Action 303

[0228] In this Action 303, the second network node 112 may determine whether or not to initiate the LTM, e.g., whether or not to send another indication, e.g., to the device 130.

[0229] The determining in this Action 303 may be based on at least one of the received first message and the received fourth indication.

[0230] In an example, the second network node 112 may decide to trigger an LTM procedure based on the first indication received from the first network node 111. In one option, the second network node 112 may determine whether an early DL synchronization procedure, also called TCI state activation procedure, may have to be triggered. In one option, the second network node 112 may determine whether an early UL synchronization procedure, also called TA acquisition procedure, may have to be triggered.

[0231] In one option, the second network node 112 may determine whether an LTM cell switch procedure may have to be triggered

[0232] The another indication may instruct the device 130 to perform the one or more LTM procedures, e.g., LTM cell switch.

[0233] Action 304

[0234] In this Action 304, the second network node 112 may initiate the LTM, e.g., the one or more LTM procedures, e.g., LTM cell switch procedure. Initiating may be understood as starting or triggering itself or, enabling or facilitating, that another entity may start or trigger. The second network node 111 may initiate an LTM procedure for the device 130, e.g., the UE. The second network node 112 may, according to this Action 304, transmit a lower layer signal, such as an LTM cell switch command MAC CE, to the device 130, indicating an LTM procedure to be executed by the device 130.

[0235] Prior to sending the lower layer signal, the second network node 112 may have performed selection of a beam in a target cell, e.g., a target beam in the LTM candidate cell indicated in an LTM cell switch command MAC CE transmitted to the device 130.

[0236] In some examples, the LTM procedure may be an early synchronization procedure, such as an early DL sync procedure, candidate TCI state activation procedure, early UL sync procedure or an TA acquisition procedure.

[0237] The initiating in this Action 304 may be responsive to the received first message.

[0238] The initiating in this Action 304 may comprise sending the another indication to the device 130. The second network 112 may send an indication, the another indication, to the device 130, e.g., the UE, to trigger an LTM procedure based on the first indication received from the first network node 111. In one option, the second network node 112 may send the another indication to the device 130, e.g., the UE, whether an early DL synchronization procedure, also called TCI state activation procedure, may have to be triggered. In one option, the second network node 112 may send an indication to the device 130, e.g., the UE, whether an early UL synchronization procedure, also called TA acquisition procedure, may have to be triggered;

[0239] In one option, the second network node 112 may send the another indication to the device 130, e.g., the UE whether a LTM cell switch procedure may have to be triggered.

[0240] In one example, the second network node 112 may send a command, e.g., MAC CE, to the device 130, e.g., the UE to trigger LTM cell switch. In another example, the second network node 112 may initiate early synchronization procedure(s) for the device 130, e.g., the UE. In one example, the initiation of early synchronization may include transmission of a lower layer signal, e.g. PDCCH order, to the device 130, e.g., the UE to trigger random access preamble transmission by the device 130, e.g., the UE to a neighbor. Cell, e.g., a target cell, using a certain preamble index, sometimes known as early UL sync. In another example, the initiation of early synchronization may include transmission of a lower layer signal, e.g., a MAC CE, to the UE to trigger activation of a TCI state in a neighbor cell, e.g., a target cell, sometimes known as candidate cell TCI state activation or early DL sync. In one example, the second network node 112 may receive information related to the early synchronization procedure, such as indication or a target cell or beam, or a preamble index. In another example, the second network node 112 may select a beam for the LTM procedure, for example, the beam in a target cell used for an LTM cell switch procedure or for the downlink sync procedure.

[0241] In one example, the beam may be selected based on a received indication from the first network node 111 , such as measurement information, e.g., an L1 or L3 measurement value, such as an RSRP or RSRQ value, for a specific beam, e.g., associated with a certain SSB or CSI-RS based beam, or an indication of a beam, e.g. indication of a TCI state.

[0242] The initiating in this Action 304 may comprise sending the a sixth indication to the third network node 113, as will be described later. The second network node 112, e.g., a source DU may, according to Action 304, reply to the third network node 113, e.g., a CU-UP a data frame, e.g., UL User Data frame, to indicate whether it accepts or rejects triggering LTM procedure. The advantage of this approach may be understood to be early data forwarding may be in place when the LTM may occur.

[0243] Action 305

[0244] In this Action 305, the second network node 112 may send the second message. The sending in this Action 305 may be responsive to the received first message. The sending in this Action 305 may be to the first network node 111.

[0245] The second message, e.g., a UE CONTEXT MODIFICATION RESPONSE, may indicate one of: i) whether or not the LTM, e.g., the one or more LTM procedures, may have been initiated, e.g., that the another indication has been sent to the device 130 instructing the device 130 to perform the LTM, e.g., LTM cell switch, ii) that the LTM, e.g., LTM cell switch, is not allowed, and iii) whether or not L3 measurements are allowed to be used for execution of the LTM, e.g., LTM cell switch.

[0246] The second network node 112, according to this Action 305, may confirm that the received request has been accepted in an UE CONTEXT MODIFICATION RESPONSE message sent to the first network node 111. In one example, the second network node 112 may receive the indicator, that is, the first indication, from the first network nodel 11 to indicate that an LTM cell switch may have to be triggered to the device 130, e.g., the UE, via an F1AP or XnAP message. The second network node 112 may transmit an acknowledge to the first network node 111 to indicate that it has successfully received the indicator about L3 measurements triggered LTM cell switch, via an F1AP message, for example, UE CONTEXT MODIFICATION RESPONSE message.

[0247] In one option, the second network node 112, e.g., the DU may indicate to the first network node 111, e.g., the CU if it will trigger LTM cell switch or not.

[0248] In one option, the second network node 112, e.g., the DU may indicate to the first network node 111, e.g., the CU if it will trigger LTM cell switch or not based on L3 measurements.

[0249] In one option, the second network node 112, e.g., the DU may respond which target DU to trigger cell switch if more than one were indicated by the first network node 111, e.g., the CU.

[0250] In one example, the second network node 112 may send a message to the first network node 111 , e.g., a UE CONTEXT SETUP RESPONSE or a UE CONTEXT MODIFICATION RESPONSE message, the message comprising an indication, e.g., a flag, to indicate that use of L3 measurements for initiating LTM cell switch is not allowed, or is allowed. In one option, a cause value may be included to indicate the reason for not initiating LTM cell switch based on L3 measurements, e.g., “L3 measurements not supported”.

[0251] In another example, the second network node 112 may send an indication to the first network node 111 , e.g., as part of F1 SETUP REQUEST or GNB-DU CONFIGURATION UPDATE F1AP message, indicating whether L3 measurements may be used for LTM cell switch execution.

[0252] In another example, wherein LTM cell switch execution is allowed / applicable based on either L1 measurements or L3 measurements, the second network node 112, e.g., the serving gNB-DU, upon execution of an LTM cell switch command towards the device 130, e.g., the UE, may send an indication to the controlling gNB-CU, to indicate whether LTM cell switch was executed based on L1 measurements or L3 measurements.

[0253] Both embodiments and / or examples described in relation to Figure 2 and Figure 3 may be implemented with the user plan solution, e.g. updating the F1-U user plane protocol. The first network node 111, e.g., the gNB-CU may send the request / measurement to the second network node 112, e.g., the gNB-DU in the DL data frame. The second network node 112, e.g., the gNB-DU may send the response / feedback to the first network node 111 , e.g., the gNB-CU in the UL data frame.

[0254] Embodiments of a computer-implemented method, performed by a third network node, such as the third network node 113, will now be described with reference to the flowchart depicted in Figure 4. The method is for handling mobility. The third network node 113 operates in a communications network, such as the communications network 100.

[0255] The third network node 113 may be, e.g., a serving gNB-CU-UP.

[0256] Several embodiments are comprised herein. The method may comprise one or more of the following actions. In a particular non-limiting example, Action 401 may be performed. In another particular non-limiting example, Action 401 and Action 402 may be performed. In some embodiments, all the actions may be performed. It should be noted that the examples herein are not mutually exclusive. One or more embodiments may be combined, where applicable. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments. All possible combinations are not described to simplify the description. A non-limiting example of the method performed by the third network node 113 is depicted in Figure 4. In Figure 4, optional actions in some embodiments may be represented with dashed lines.

[0257] The detailed description of some of the following corresponds to the same references provided above, in relation to the actions described for the first network node 111 and will thus not be repeated here to simplify the description. For example, the communications network 100 may support, or operate in, New Radio (NR).

[0258] Action 401

[0259] In this Action 401 , the third network node 113 receives the second indication.

[0260] The receiving in this Action 401 of the second indication is from the first network node 111 operating in the communications network 100.

[0261] The second indication requests whether or not the one or more LTM procedures are possible e.g., based on at least one of L1 and L3 measurements.

[0262] The one or more LTM procedures may be, e.g., an LTM cell switch to the one or more second cells 122 for the device 130 operating in the communications network 100. The one or more second cells 122 may be served by the fourth network node 114 managed by the third network node 113.

[0263] In one example, the third network node 113 may receive the indicator, that is, the second indication, from the first network node 111 to indicate that an LTM cell switch may be triggered to the device 130, e.g., the UE based on L3 measurements, via an E1AP message. In one option, the indicator, that is, the second indication, may be an enumerated value, corresponding to “0” or “1” or “trigger LTM cell switch” or “not trigger LTM cell switch” for each LTM candidate cell configured by the gNB-DU. In one option, the E1AP message may be a Class 1 UE associated signaling, e.g., BEARER CONTEXT MODIFICATION REQUEST. In one option the first network node 111 , e.g., the CLI-CP may signal to the third network node 113, e.g., the CU-LIP that it may have to start early data forwarding to another CU-LIP if a change of CU-LIP is foreseen.

[0264] In one option, the E1AP message may be a Class 1 UE associated signaling, e.g., BEARER CONTEXT MODIFICATION REQUEST

[0265] Action 402

[0266] In this Action 402, the third network node 113 sends the third indication.

[0267] The sending in this Action 402 is to the first network node 111.

[0268] The sending in this Action 402 is responsive to the received second indication.

[0269] The third indication indicates whether or not the one or more LTM procedures are possible.

[0270] The third indication may indicate whether or not the one or more LTM procedures, e.g., the LTM cell switch to one or more second cells 122, may be possible, e.g., based on at least one of L1 and L3 measurements.

[0271] In another example, the third network node 113 may transmit an acknowledge to the first network node 111 to indicate that it may send the cell switch command to the device 130, e.g., the UE to trigger LTM execution, via an F1AP message, for example, UE CONTEXT MODIFICATION RESPONSE message. In one example, the third network node 113 may send a command, e.g., MAC CE, to the UE to trigger LTM cell switch.

[0272] In some embodiments, the method may further, or alternatively, comprise one or more of the following actions.

[0273] Action 403

[0274] In this Action 403, the third network node 113 may send the fourth indication.

[0275] The sending in this Action 403 may be to the second network node 112.

[0276] The fourth indication may indicate whether or not the LTM, e.g., the one or more LTM procedures, e.g., LTM cell switch, are possible.

[0277] The third network node 113 may, according to this Action 403, transmit a data frame, e.g., DL User Data frame, to the fourth network node 114 with one indicator to indicate that an LTM procedure may be going to be triggered. The indication may be a request to perform an LTM cell switch procedure. In one example the message may include an indicated LTM candidate cell. The message may in one example include a measurement received from the device 130.

[0278] Action 404

[0279] In this Action 404, the third network node 113 may send the fifth indication.

[0280] The sending in this Action 404 may be to the device 130.

[0281] The sending in this Action 404 may be based on the received second indication.

[0282] The fifth indication may trigger the one or more LTM procedures. The fifth indication may be, e.g., a MAC CE.

[0283] In some examples, one or more of the following may apply: a) the first network node 111 may serve the device 130, b) the third network node 113 may be a candidate to serve the device 130, c) the first network node 111 may be a Central Unit, d) the third network node 113 may be another CU, e) the one or more LTM procedures may comprise one or more of: i) the LTM cell switch procedure from the first cell 121 to the second cell 122, ii) the early synchronization procedure, iii) the candidate TCI procedure, e.g., a candidate cell or beam TCI procedure, iv) the early uplink synchronization procedure, and v) the TA acquisition procedure.

[0284] Embodiments of a computer-implemented method, performed by a device, such as the device 130, will now be described with reference to the flowchart depicted in Figure 5. The method is for handling mobility. The device 130 operates in a communications network, such as the communications network 100.

[0285] Several embodiments are comprised herein. The method may comprise one or more of the following actions. In a particular non-limiting example, Action 501 may be performed. In another particular non-limiting example, Action 501 and Action 502 may be performed. In some embodiments, all the actions may be performed. It should be noted that the examples herein are not mutually exclusive. One or more embodiments may be combined, where applicable. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments. All possible combinations are not described to simplify the description. A non-limiting example of the method performed by the device 130 is depicted in Figure 5. In Figure 5, optional actions in some embodiments may be represented with dashed lines.

[0286] The detailed description of some of the following corresponds to the same references provided above, in relation to the actions described for the first network node 111 and will thus not be repeated here to simplify the description. For example, the communications network 100 may support, or operate in, New Radio (NR).

[0287] Action 501

[0288] The device 130 may be configured to perform L3 measurements for neighbor cells. Optionally, the device 130 may be also configured for LTM, including LTM candidate cells, such as an LTM candidate cell configuration for at least one target cell. The device 130 may perform measurements on neighboring cells, including LTM candidate cells.

[0289] In this Action 501, the device 130 sends the previous message.

[0290] The sending in this Action 501 is to the first network node 111 operating in the communications network 100. The previous message indicates the one or more L3 measurements.

[0291] In some examples, one or more of the following may apply: a) the first network node 111 may serve the device 130, b) the second network node 112 may serve the device 130, c) the first network node 111 may be a Central Unit, d) the second network node 112 may be a Distributed Unit, e) the one or more LTM procedures may comprise one or more of: i) the LTM cell switch procedure from the first cell 121 to the second cell 122, ii) the early synchronization procedure, iii) the candidate TCI procedure, e.g., a candidate cell or beam TCI procedure, iv) the early uplink synchronization procedure, and v) the TA acquisition procedure.

[0292] The device 130 may be a UE which may be configured with a serving cell for LTM.

[0293] The device 130 may, according to this Action 501, transmit an L3 measurement report, e.g., triggered by an A3 or A5 type of event, indicating a neighbor cell and a measurement value, such as RSRP, RSRQ, for the neighbor cell and optionally a beam in that cell.

[0294] In some embodiments, the method may further, or alternatively, comprise the following action.

[0295] Action 502

[0296] In this Action 502, the device 130 receives the another indication.

[0297] The receiving in this Action 502 is from the second network node 112 managed by the first network node 111.

[0298] The another indication instructs the device 130 to perform the one or more LTM procedures, e.g., LTM cell switch. The receiving in this Action 502 of the another indication is based on the sent previous message.

[0299] In one example, the device 130 may receive an indication, that is, the another indication, from the first network node 111, and / or the second network node 112 to trigger an LTM procedure to the second network node 112.

[0300] The another indication to trigger an LTM procedure may be one or more of the following: i) an indication whether an early DL synchronization procedure, also called TCI state activation procedure, may have to be triggered, ii) an indication whether an early UL synchronization procedure, also called TA acquisition procedure, may have to be triggered, iii) an indication whether a LTM cell switch procedure may have to be triggered, and / or iv) one or more LTM candidate identifiers to which the early DL synchronization, and / or the early UL synchronization, and / or LTM cell switch procedure may have to be executed.

[0301] The device 130 may perform e.g., an LTM cell switch procedure towards an LTM candidate cell indicated in the command.

[0302] In some embodiments, the method may further, or alternatively, comprise the following action. Action 503

[0303] In this Action 503, the device 130 may receive the fifth indication.

[0304] The receiving in this Action 503 may be based on the sent previous message.

[0305] The receiving in this Action 503 may be from the third network node 113 operating in the communications network 100.

[0306] The fifth indication may trigger the one or more LTM procedures.

[0307] The fifth indication to trigger an LTM procedure may be one or more of the following: i) an indication whether an early DL synchronization procedure, also called TCI state activation procedure, may have to be triggered, ii) an indication whether an early UL synchronization procedure, also called TA acquisition procedure, may have to be triggered, iii) an indication whether a LTM cell switch procedure may have to be triggered, and / or iv) one or more LTM candidate identifiers to which the early DL synchronization, and / or the early UL synchronization, and / or LTM cell switch procedure may have to be executed.

[0308] Figure 6 illustrates a message sequence chart in one example of embodiments herein. In this example, an existing F1AP procedure may be reused to trigger LTM from the CU based on L3 measurements. In this example, the first network node 111 is a CU, the second network node 112 is a source DU, the fourth network node 114 is a candidate CU and the device 130 is a UE. The main steps in this example may be as follows. Step 1) The UE may be configured to perform L3 measurements for neighbor cells. Optionally, the UE may be also configured for LTM, including LTM candidate cells, such as an LTM candidate cell configuration for at least one target cell. The LTM configuration may also be performed after step 2. Step 2) The UE may perform measurements on neighboring cells, including LTM candidate cells. The UE may, according to Action 501 , transmit an L3 measurement report, e.g. triggered by an A3 or A5 type of event, indicating a neighbor cell and a measurement value, such as RSRP, RSRQ, for the neighbor cell and optionally a beam in that cell. Step 3) The CU may, according to Action 202, decide to trigger an LTM cell switch procedure for the UE towards an LTM candidate cell. The CU may at this point perform LTM configuration of the UE, such as configuring the indicated neighboring cell as an LTM candidate cell for the UE. Step 4) The CU, according to Action 205, may transmit a UE CONTEXT MODIFICATION REQUEST message to the source DU. The message may include an indication about an LTM procedure. In this example, the indication may be a request to perform an LTM cell switch procedure. In one example the message may include an indicated LTM candidate cell. The message may in one example include a measurement received from the UE. Step 5) The source DU may, according to Action 304, transmit a lower layer signal, such as an LTM cell switch command MAC CE, to the UE, indicating an LTM procedure to be executed by the UE. The UE may perform in this example an LTM cell switch procedure towards an LTM candidate cell indicated in the command. Prior to sending the lower layer signal, the DU may have performed selection of a beam in a target cell, e.g., a target beam in the LTM candidate cell indicated in an LTM cell switch command MAC CE transmitted to the UE. Step 6) The DU, according to Action 305, may confirm that the received request has been accepted in an UE CONTEXT MODIFICATION RESPONSE message sent to the CU.

[0309] Figure 7 illustrates a message sequence chart in one example of embodiments herein. In this example, the first network node 111 is a CU, the second network node 112 is a source DU, the fourth network node 114 is a candidate CU and the device 130 is a UE. In this example, a new class-2 F1AP procedure is introduced to trigger LTM from the CU based on L3 measurements. The main steps in this example may be as follows. Steps 1-3 may be understood to be the same as the corresponding steps in Figure 6. Step 4) The CU, according to Action 205, may transmit a new F1AP message, such as an LTM cell switch command F1AP message to the source DU. The message may include an indication about an LTM procedure. In this example, the indication is a request to perform an LTM cell switch procedure. In one example, the message may include an indicated LTM candidate cell. The message may in one example include a measurement received from the UE. Step 5 may be understood to be the same as the corresponding step in Figure 6.

[0310] Figure 8 illustrates a message sequence chart in one example of embodiments herein. In this example, the first network node 111 is a CU-CP, the second network node 112 is a source DU, the third network node 113 is a candidate DU, the fourth network node 114 is a CU-UP and the device 130 is a UE. In this example, the user plane handling is illustrated during LTM triggered from the CU based on L3 measurements. The main steps in this example may be as follows. Steps 1-3 may be understood to be the same as the corresponding steps in Figure 6. Step 4-5) The CU-CP may, according to Action 203, transmit an E1AP message, e.g., BEARER CONTEXT MODIFICATION REQUEST, to indicate to the CU-UP that an LTM procedure needs to be triggered to the source DU. The CU-UP according to Action 402, may send a BEARER CONTEXT MODIFICATION RESPONSE to acknowledge that it may receive the request message. Step 6) The CU-UP may, according to Action 403, transmit a data frame, e.g., DL User Data frame, to the source DU with one indicator to indicate that an LTM procedure will be triggered. In this example, the indication may be a request to perform an LTM cell switch procedure. In one example the message may include an indicated LTM candidate cell. The message may in one example include a measurement received from the UE. Step 7) may be understood to be the same as step 5 in Figure 6. Step 8) The source DU may, according to Action 304, reply to the CU-UP a data frame, e.g., UL User Data frame, to indicate whether it accepts or rejects triggering LTM procedure. The advantage of this approach may be understood to be early data forwarding may be in place when the LTM may occur.

[0311] Figure 9 illustrates a flowchart for the steps performed by first network node 111 in one example of embodiments herein. The main steps performed by the first network node in this example may be as follows. Step 5001) The first network node 111 , according to Action 201, may receive, from the device 130 an L3 measurement report. Step 5002) The first network node 111 , according to Action 205, may decide to trigger an LTM procedure, such as an LTM cell switch procedure, for the device 130 and may transmit a request to the second network node 112 including a request to initiate an LTM procedure.

[0312] Figure 10 illustrates a flowchart for the steps performed by the second network node 112 in one example of embodiments herein. The main steps performed by the second network node in this example may be as follows. Step 6001) The second network node 112, according to Action 301 , may receive a message from the first network node 111 including a request to initiate an LTM procedure. Step 6002) The second network node 112, according to Action 304, may initiate an LTM procedure for the device 130, such as an LTM cell switch procedure.

[0313] Figure 11 is a schematic diagram illustrating Figure 8.3.x.2-1 Measurement Notification procedure. Successful operation according to Example D above. This may be understood to be an example of Action 205 and Action 301.

[0314] Figure 12 is a schematic diagram illustrating Figure 8.3.4.2-1 : UE Context Modification procedure. Successful operation according to Example C above. The sending of the UE context modification request may be understood to be an example of Action 205 and Action 301. The receiving of the UE context modification response may be understood to be an example of Action 206 and Action 305.

[0315] Certain embodiments disclosed herein may provide one or more of the following technical advantage(s), which may be summarized as follows.

[0316] The proposed approach may be understood to be to enable the second network node 112, e.g., a gNB-DU, to trigger one or more LTM procedures if the network decides to use exclusively the L3 measurements for LTM. This may avoid that the UE may perform L1 measurements on candidate cells, and report those measurements to the network, which may decrease implementation complexity in the device 130, e.g., the UE, and the network and may also decrease power consumption at the device 130, e.g., UE power consumption. Figure 13 depicts an example of the arrangement that the first network node 111 may comprise to perform the method actions described above in relation to Figure 2 and / or any of Figures 6-9 and / or Figures 11-12. The first network node 111 is for handling mobility. The first network node 111 is configured to operate in the communications network 100.

[0317] Several embodiments are comprised herein. It should be noted that the examples herein are not mutually exclusive. One or more embodiments may be combined, where applicable. All possible combinations are not described to simplify the description. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments. The detailed description of some of the following corresponds to the same references provided above, in relation to the actions described for the first network node 111 and will thus not be repeated here. For example, the communications network 100 may be a 5G network.

[0318] The first network node 111 is configured and / or operable to perform the sending in Action 205, e.g. by means of a processing circuitry 1301 within the first network node 111 configured to, send the first message to the second network node 112 configured to operate in the communications network 100. The first message is configured to comprise the first indication configured to indicate the one or more LTM procedures for the device 130 configured to operate in the communications network 100. The first message is configured to indicate the one or more target cells or beams.

[0319] That the first message is configured to indicate the one or more target cells or beams may be understood to mean that the first message may be configured to indicate one or more target cells, one or more target beams, or that the first message may be configured to indicate one or more target cells and target beams. The one or more target cells may be configured to be e.g., the one of the one or more second cells 122.

[0320] In some embodiments, one or more of the following may apply: a) the first network node 111 may be configured to serve the device 130, b) the second network node 112 may be configured to serve the device 130, c) the first network node 111 may be configured to be a CU, d) the second network node 112 may be configured to be a DU, e) the one or more LTM procedures may be configured to comprise one or more of: i) the LTM cell switch procedure from the first cell 121 to the second cell 122, ii) the early synchronization procedure, iii) the candidate TCI procedure, e.g., a candidate cell or beam TCI procedure, iv) the early uplink synchronization procedure, and v) the TA acquisition procedure, f) the first message may be configured to be the F1AP message, g) the first message may be configured to be Class 1 UE associated signalling or a Class 2 UE associated signalling, h) the first message may be configured to indicate the one or more L3 measurements performed by the device 130, i) the first message may be configured to request the one or more L1 measurements performed by the device 130, j) the first message may be configured to indicate the change in a triggering LTM cell switch decision for one or more candidate cells, k) the first indication may be configured to be one of implicit and explicit, and I) the first indication may be configured to be per candidate cell or for all candidate cells.

[0321] In some embodiments, the first network node 111 may be further configured with one or more of the following three configurations:

[0322] The first network node 111 may be configured and / or operable to perform the receiving in this Action 201, e.g. by means of the processing circuitry 1301 within the first network node 111 configured to, receive the previous message from the device 130. The previous message may be configured to indicate the one or more L3 measurements. The sending of the first message may be configured to be based on the previous message configured to be received.

[0323] The first network node 111 may be configured and / or operable to perform the determining in Action 202, e.g. by means of the processing circuitry 1301 within the first network node 111 configured to, determine, based on the previous message configured to be received, whether or not to initiate the one or more LTM procedures. The sending of the first message may be configured to be based on the result of the determination.

[0324] The first network node 111 may be configured and / or operable to perform the receiving in Action 206, e.g. by means of the processing circuitry 1301 within the first network node 111 configured to, receive, responsive to the first message configured to be sent, the second message from the second network node 112. The second message may be configured to indicate one of: i) whether or not the one or more LTM procedures have been initiated, ii) that the LTM is not allowed, and iii) whether or not L3 measurements are allowed to be used for execution of the LTM.

[0325] In some embodiments, the first network node 111 may be further configured with the following two configurations:

[0326] The first network node 111 may be configured and / or operable to perform the sending in Action 203, e.g. by means of the processing circuitry 1301 within the first network node 111 configured to, send the second indication to the third network node 113 configured to operate in the communications network 100. The second indication may be configured to request whether or not the one or more LTM procedures are possible.

[0327] The first network node 111 may be configured and / or operable to perform the receiving in Action 204, e.g. by means of the processing circuitry 1301 within the first network node 111 configured to, receive, responsive to the second indication configured to be sent, the third indication from the third network node 113. The third indication may be configured to indicate whether or not one or more LTM procedures are possible. In some embodiments, the determining may be configured to be based on one or more of: failing to receive L1 measurements, the frequency of the carrier used, the one or more conditions, the at least one property of the L3 measurements fulfilling the first condition, the availability of specific L1 measurements, and the availability of the specific L1 measurements for one cell.

[0328] In some embodiments, one of the following may apply: a) the first message may be configured to indicate whether or not the one or more LTM procedures are possible, b) the first message may be configured to indicate the request to initiate the one or more LTM procedures, c) the first message may be configured to indicate the preference to initiate the one or more LTM procedures, d) the first message may be configured to indicate the preference to initiate the one or more LTM procedures based on L3 measurements, e) the first message may be configured to indicate the preference to initiate the one or more LTM procedures based on L1 measurements, f) the first message may be configured to be the MEASUREMENT NOTIFICATION, g) the first message may be configured to be the UE CONTEXT SETUP REQUEST, h) the first message may be configured to be the UE CONTEXT MODIFICATION REQUEST, i) the first message may be configured to be the CU-DU Cell Switch Notification, and j) the first message may be configured to be the MEASUREMENT TRANSFER message.

[0329] The embodiments herein in the first network node 111 may be implemented through one or more processors, such as a processing circuitry 1301 in the first network node 111 depicted in Figure 13a, together with computer program code for performing the functions and actions of the embodiments herein. A processor, as used herein, may be understood to be a hardware component. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the embodiments herein when being loaded into the first network node 111. One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may furthermore be provided as pure program code on a server and downloaded to the first network node 111.

[0330] The processing circuitry 1301 may be configured to, or operable to, perform the method actions according to Figure 2 and / or any of Figures 6-9 and / or Figures 11-12.

[0331] The first network node 111 may further comprise a memory 1302 comprising one or more memory units. The memory 1302 is arranged to be used to store obtained information, store data, configurations, schedulings, and applications etc. to perform the methods herein when being executed in the first network node 111.

[0332] In some embodiments, the first network node 111 may receive information from, e.g., the second network node 112, the third network node 113, the fourth network node 114, the device 130, and / or another structure in the communications network 100, through a receiving port 1303. In some embodiments, the receiving port 1303 may be, for example, connected to one or more antennas in first network node 111. In other embodiments, the first network node 111 may receive information from another structure in the communications network 100 through the receiving port 1303. Since the receiving port 1303 may be in communication with the processing circuitry 1301, the receiving port 1303 may then send the received information to the processing circuitry 1301. The receiving port 1303 may also be configured to receive other information.

[0333] The processing circuitry 1301 in the first network node 111 may be further configured to transmit or send information to e.g., the second network node 112, the third network node 113, the fourth network node 114, the device 130, and / or another structure in the communications network 100, through a sending port 1304, which may be in communication with the processing circuitry 1301 , and the memory 1302.

[0334] Those skilled in the art will also appreciate that the processing circuitry 1301 described above may comprise a combination of analog and digital modules, and / or one or more processors configured with software and / or firmware, e.g., stored in memory, that, when executed by the one or more processors such as the processing circuitry 1301, perform as described above. One or more of these processors, as well as the other digital hardware, may be included in a single Application-Specific Integrated Circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a System-on-a-Chip (SoC).

[0335] Also, in some embodiments, the first network node 111 may be configured to perform the actions of Figure 2 and / or any of Figures 6-9 and / or Figures 11-12 with respective units that may be implemented as one or more applications running on one or more processors such as the processing circuitry 1301.

[0336] The first network node 111 may be configured to perform any of the Actions described in relation to Figure 2 and / or any of Figures 6-9 and / or Figures 11-12, e.g., by means of the processing circuitry 1301 within the first node 111 , configured to perform any of such actions.

[0337] Thus, the methods according to the embodiments described herein for the first network node 111 may be respectively implemented by means of a computer program 1305 product, comprising instructions, i.e., software code portions, which, when executed on at least one processing circuitry 1301 , cause the at least one processing circuitry 1301 to carry out the actions described herein, as performed by the first network node 111. The computer program 1305 product may be stored on a computer-readable storage medium 1306. The computer- readable storage medium 1306, having stored there on the computer program 1305, may comprise instructions which, when executed on at least one processing circuitry 1301, cause the at least one processing circuitry 1301 to carry out the actions described herein, as performed by the first network node 111. In some embodiments, the computer-readable storage medium 1306 may be a non-transitory computer-readable storage medium, such as a CD ROM disc, or a memory stick. In other embodiments, the computer program 1305 product may be stored on a carrier containing the computer program 1305 just described, wherein the carrier is one of an electronic signal, optical signal, radio signal, or the computer-readable storage medium 1306, as described above.

[0338] The first network node 111 may comprise a communication interface configured to facilitate communications between the first network node 111 and other nodes or devices, e.g., the second network node 112, the third network node 113, the fourth network node 114, the device 130, and / or another structure in the communications network 100. The interface may, for example, include a transceiver configured to transmit and receive radio signals over an air interface in accordance with a suitable standard.

[0339] In other embodiments, the first network node 111 may also comprise a radio circuitry 1307, which may comprise e.g., the second network node 112, the third network node 113, the fourth network node 114, the device 130, and / or another structure in the communications network 100. Circuitry may be understood herein as a hardware component.

[0340] Hence, embodiments herein also relate to the first network node 111 comprising the processing circuitry 1301 and the memory 1302, said memory 1302 containing instructions executable by said processing circuitry 1301 , whereby the first network node 111 is operative to perform the actions described herein in relation to the first network node 111 , e.g., in Figure 2 and / or any of Figures 6-9 and / or Figures 11-12.

[0341] Figure 14 depicts an example of the arrangement that the second network node 112 may comprise to perform the method actions described above in relation to Figure 3, and / or any of Figures 6-8 and / or Figures 10-12. The second network node 112 is for handling the mobility. The second network node 112 is configured to operate in the communications network 100.

[0342] Several embodiments are comprised herein. It should be noted that the examples herein are not mutually exclusive. One or more embodiments may be combined, where applicable. All possible combinations are not described to simplify the description. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments. The detailed description of some of the following corresponds to the same references provided above, in relation to the actions described for the second network node 112 and will thus not be repeated here. For example, the communications network 100 may be a 5G network.

[0343] The second network node 112 is configured and / or operable to perform the receiving in Action 301, e.g. by means of a processing circuitry 1401 within the second network node 112 configured to, receive the first message from the first network node 111 configured to operate in the communications network 100. The first message is configured to comprise the first indication configured to indicate the one or more LTM procedures, for the device 130 configured to operate in the communications network 100. The first message is configured to indicate the one or more target cells or beams.

[0344] In some embodiments, one or more of the following may apply: a) the first network node 111 may be configured to serve the device 130, b) the second network node 112 may be configured to serve the device 130, c) the first network node 111 may be configured to be a CU, d) the second network node 112 may be configured to be a DU, e) the one or more LTM procedures may be configured to comprise one or more of: i) the LTM cell switch procedure from the first cell 121 to the second cell 122, ii) the early synchronization procedure, iii) the candidate TCI procedure, e.g., a candidate cell or beam TCI procedure, iv) the early uplink synchronization procedure, and v) the TA acquisition procedure, f) the first message may be configured to be the F1AP message, g) the first message may be configured to be Class 1 UE associated signalling or a Class 2 UE associated signalling, h) the first message may be configured to indicate the one or more L3 measurements performed by the device 130, i) the first message may be configured to request the one or more L1 measurements performed by the device 130, j) the first message may be configured to indicate the change in the triggering LTM cell switch decision for one or more candidate cells, k) the first indication may be configured to be one of implicit and explicit, and I) the first indication may be configured to be per candidate cell or for all candidate cells.

[0345] In some embodiments, one of the following may apply: a) the first message may be configured to indicate whether or not the one or more LTM procedures are possible, b) the first message may be configured to indicate the request to initiate the one or more LTM procedures, c) the first message may be configured to indicate the preference to initiate the one or more LTM procedures, d) the first message may be configured to indicate the preference to initiate the one or more LTM procedures based on L3 measurements, e) the first message may be configured to indicate the preference to initiate the one or more LTM procedures based on L1 measurements, f) the first message may be configured to be the MEASUREMENT NOTIFICATION, g) the first message may be configured to be the UE CONTEXT SETUP REQUEST, h) the first message may be configured to be the UE CONTEXT MODIFICATION REQUEST, i) the first message may be configured to be the CU-DU Cell Switch Notification, and j) the first message may be configured to be the MEASUREMENT TRANSFER message.

[0346] In some embodiments, the second network node 112 may be further configured with one or more of the following four configurations.

[0347] The second network node 112 may be configured and / or operable to perform the receiving in Action 302, e.g. by means of the processing circuitry 1401 within the second network node 112 configured to, receive, from the third network node 113 or the fourth network node 114 configured to operate in the communications network 100, the fourth indication configured to indicate whether or not the LTM is possible.

[0348] The second network node 112 may be configured and / or operable to perform the determining in Action 303, e.g. by means of the processing circuitry 1401 within the second network node 112 configured to, determine, based on at least one of the first message and the received fourth indication configured to be received, whether or not to initiate the LTM.

[0349] The second network node 112 may be configured and / or operable to perform the initiating in Action 304, e.g. by means of the processing circuitry 1401 within the second network node 112 configured to, initiate, responsive to the first message configured to be received, the one or more LTM procedures.

[0350] The second network node 112 may be configured and / or operable to perform the sending in Action 305, e.g. by means of the processing circuitry 1401 within the second network node 112 configured to, send, responsive to the first message configured to be received, the second message to the first network node 111. The second message may be configured to indicate one of: i) whether or not the one or more LTM procedures have been initiated, ii) that the LTM is not allowed, and iii) whether or not L3 measurements are allowed to be used for execution of the LTM.

[0351] The embodiments herein in the second network node 112 may be implemented through one or more processors, such as a processing circuitry 1401 in the second network node 112 depicted in Figure 14a, together with computer program code for performing the functions and actions of the embodiments herein. A processor, as used herein, may be understood to be a hardware component. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the embodiments herein when being loaded into the second network node 112. One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may furthermore be provided as pure program code on a server and downloaded to the second network node 112.

[0352] The processing circuitry 1401 may be configured to, or operable to, perform the method actions according to Figure 3, and / or any of Figures 6-8 and / or Figures 10-12.

[0353] The second network node 112 may further comprise a memory 1402 comprising one or more memory units. The memory 1402 is arranged to be used to store obtained information, store data, configurations, schedulings, and applications etc. to perform the methods herein when being executed in the second network node 112.

[0354] In some embodiments, the second network node 112 may receive information from, e.g., the first network node 111 , the third network node 113, the fourth network node 114, the device 130, and / or another structure in the communications network 100, through a receiving port 1403. In some embodiments, the receiving port 1403 may be, for example, connected to one or more antennas in second network node 112. In other embodiments, the second network node 112 may receive information from another structure in the communications network 100 through the receiving port 1403. Since the receiving port 1403 may be in communication with the processing circuitry 1401 , the receiving port 1403 may then send the received information to the processing circuitry 1401. The receiving port 1403 may also be configured to receive other information.

[0355] The processing circuitry 1401 in the second network node 112 may be further configured to transmit or send information to e.g., the first network node 111, the third network node 113, the fourth network node 114, the device 130, and / or another structure in the communications network 100, through a sending port 1404, which may be in communication with the processing circuitry 1401 , and the memory 1402.

[0356] Those skilled in the art will also appreciate that the processing circuitry 1401 described above may comprise a combination of analog and digital modules, and / or one or more processors configured with software and / or firmware, e.g., stored in memory, that, when executed by the one or more processors such as the processing circuitry 1401, perform as described above. One or more of these processors, as well as the other digital hardware, may be included in a single Application-Specific Integrated Circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a System-on-a-Chip (SoC).

[0357] Also, in some embodiments, the second network node 112 may be configured to perform the actions of Figure 3, and / or any of Figures 6-8 and / or Figures 10-12 with respective units that may be implemented as one or more applications running on one or more processors such as the processing circuitry 1401.

[0358] Also, in some embodiments, the first network node 111 may be configured to perform the actions of Figure 3, and / or any of Figures 6-8 and / or Figures 10-12 with respective units that may be implemented as one or more applications running on one or more processors such as the processing circuitry 1301.

[0359] Thus, the methods according to the embodiments described herein for the second network node 112 may be respectively implemented by means of a computer program 1405 product, comprising instructions, i.e., software code portions, which, when executed on at least one processing circuitry 1401 , cause the at least one processing circuitry 1401 to carry out the actions described herein, as performed by the second network node 112. The computer program 1405 product may be stored on a computer-readable storage medium 1406. The computer-readable storage medium 1406, having stored thereon the computer program 1405, may comprise instructions which, when executed on at least one processing circuitry 1401 , cause the at least one processing circuitry 1401 to carry out the actions described herein, as performed by the second network node 112. In some embodiments, the computer-readable storage medium 1406 may be a non-transitory computer-readable storage medium, such as a CD ROM disc, or a memory stick. In other embodiments, the computer program 1405 product may be stored on a carrier containing the computer program 1405 just described, wherein the carrier is one of an electronic signal, optical signal, radio signal, or the computer-readable storage medium 1406, as described above.

[0360] The second network node 112 may comprise a communication interface configured to facilitate communications between the second network node 112 and other nodes or devices, e.g., the first network node 111 , the third network node 113, the fourth network node 114, the device 130, and / or another structure in the communications network 100. The interface may, for example, include a transceiver configured to transmit and receive radio signals over an air interface in accordance with a suitable standard.

[0361] In other embodiments, the second network node 112 may also comprise a radio circuitry 1407, which may comprise e.g., the receiving port 1403 and the sending port 1404. The radio circuitry 1407 may be configured to set up and maintain at least a wireless connection with the first network node 111 , the third network node 113, the fourth network node 114, the device 130, and / or another structure in the communications network 100. Circuitry may be understood herein as a hardware component.

[0362] Hence, embodiments herein also relate to the second network node 112 comprising the processing circuitry 1401 and the memory 1402, said memory 1402 containing instructions executable by said processing circuitry 1401 , whereby the second network node 112 is operative to perform the actions described herein in relation to the second network node 112, e.g., in Figure 3, and / or any of Figures 6-8 and / or Figures 10-12.

[0363] Figure 15 depicts an example of the arrangement that the third network node 113 may comprise to perform the method actions described above in relation to Figure 4, and / or any of Figures 6-8. The third network node 113 is for handling mobility. The third network node 113 is configured to operate in the communications network 100.

[0364] Several embodiments are comprised herein. It should be noted that the examples herein are not mutually exclusive. One or more embodiments may be combined, where applicable. All possible combinations are not described to simplify the description. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments. The detailed description of some of the following corresponds to the same references provided above, in relation to the actions described for the third network node 113 and will thus not be repeated here. For example, the communications network 100 may be a 5G network. The third network node 113 is configured and / or operable to perform the receiving in Action 401, e.g. by means of a processing circuitry 1501 within the third network node 113 configured to, receive the second indication from the first network node 111 configured to operate in the communications network 100. The second indication is configured to request whether or not the one or more LTM procedures are possible.

[0365] The third network node 113 is also configured and / or operable to perform the sending in Action 402, e.g. by means of the processing circuitry 1501 within the third network node 113 configured to, send, responsive to the second indication configured to be received, the third indication to the first network node 111. The third indication is configured to indicate whether or not the one or more LTM procedures are possible.

[0366] In some embodiments, the third network node 113 may be further configured with one or more of the following two configurations.

[0367] The third network node 113 may be configured and / or operable to perform the sending in Action 403, e.g. by means of the processing circuitry 1501 within the third network node 113 configured to, send, to the second network node 112 configured to operate in the communications network 100, the fourth indication configured to indicate whether or not the one or more LTM procedures are possible.

[0368] The third network node 113 may be configured and / or operable to perform the sending in Action 404, e.g. by means of the processing circuitry 1501 within the third network node 113 configured to, send, based on the second indication configured to be received, the fifth indication to the device 130. The fifth indication may be configured to trigger the one or more LTM procedures.

[0369] In some embodiments, one or more of the following may apply: a) the first network node 111 may be configured to serve the device 130, b) the third network node 113 may be configured to be the candidate to serve the device 130, c) the first network node 111 may be configured to be the CU, d) the third network node 113 may be configured to be another CU, and e) the one or more LTM procedures may be configured to comprise one or more of: i) the LTM cell switch procedure from the first cell 121 to the second cell 122, ii) the early synchronization procedure, iii) the candidate TCI procedure, e.g., a candidate cell or beam TCI procedure, iv) the early uplink synchronization procedure, and v) the TA acquisition procedure.

[0370] The embodiments herein in the third network node 113 may be implemented through one or more processors, such as a processing circuitry 1501 in the third network node 113 depicted in Figure 15a, together with computer program code for performing the functions and actions of the embodiments herein. A processor, as used herein, may be understood to be a hardware component. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the embodiments herein when being loaded into the third network node 113. One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may furthermore be provided as pure program code on a server and downloaded to the third network node 113.

[0371] The processing circuitry 1501 may be configured to, or operable to, perform the method actions according to Figure 4, and / or any of Figures 6-8.

[0372] The third network node 113 may further comprise a memory 1502 comprising one or more memory units. The memory 1502 is arranged to be used to store obtained information, store data, configurations, schedulings, and applications etc. to perform the methods herein when being executed in the third network node 113.

[0373] In some embodiments, the third network node 113 may receive information from, e.g., the first network node 111 , the second network node 112, the fourth network node 114, the device 130, and / or another structure in the communications network 100, through a receiving port 1503. In some embodiments, the receiving port 1503 may be, for example, connected to one or more antennas in third network node 113. In other embodiments, the third network node 113 may receive information from another structure in the communications network 100 through the receiving port 1503. Since the receiving port 1503 may be in communication with the processing circuitry 1501 , the receiving port 1503 may then send the received information to the processing circuitry 1501. The receiving port 1503 may also be configured to receive other information.

[0374] The processing circuitry 1501 in the third network node 113 may be further configured to transmit or send information to e.g., the first network node 111 , the second network node 112, the fourth network node 114, the device 130, and / or another structure in the communications network 100, through a sending port 1504, which may be in communication with the processing circuitry 1501, and the memory 1502.

[0375] Those skilled in the art will also appreciate that the processing circuitry 1501 described above may comprise a combination of analog and digital modules, and / or one or more processors configured with software and / or firmware, e.g., stored in memory, that, when executed by the one or more processors such as the processing circuitry 1501, perform as described above. One or more of these processors, as well as the other digital hardware, may be included in a single Application-Specific Integrated Circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a System-on-a-Chip (SoC).

[0376] Also, in some embodiments, the third network node 113 may be configured to perform the actions of Figure 4, and / or any of Figures 6-8 with respective units that may be implemented as one or more applications running on one or more processors such as the processing circuitry 1501.

[0377] Also, in some embodiments, the first network node 111 may be configured to perform the actions of Figure 4, and / or any of Figures 6-8 with respective units that may be implemented as one or more applications running on one or more processors such as the processing circuitry 1301.

[0378] Thus, the methods according to the embodiments described herein for the third network node 113 may be respectively implemented by means of a computer program 1505 product, comprising instructions, i.e., software code portions, which, when executed on at least one processing circuitry 1501 , cause the at least one processing circuitry 1501 to carry out the actions described herein, as performed by the third network node 113. The computer program 1505 product may be stored on a computer-readable storage medium 1506. The computer- readable storage medium 1506, having stored thereon the computer program 1505, may comprise instructions which, when executed on at least one processing circuitry 1501 , cause the at least one processing circuitry 1501 to carry out the actions described herein, as performed by the third network node 113. In some embodiments, the computer-readable storage medium 1506 may be a non-transitory computer-readable storage medium, such as a CD ROM disc, or a memory stick. In other embodiments, the computer program 1505 product may be stored on a carrier containing the computer program 1505 just described, wherein the carrier is one of an electronic signal, optical signal, radio signal, or the computer-readable storage medium 1506, as described above.

[0379] The third network node 113 may comprise a communication interface configured to facilitate communications between the third network node 113 and other nodes or devices, e.g., the first network node 111 , the second network node 112, the fourth network node 114, the device 130, and / or another structure in the communications network 100. The interface may, for example, include a transceiver configured to transmit and receive radio signals over an air interface in accordance with a suitable standard.

[0380] In other embodiments, the third network node 113 may also comprise a radio circuitry 1507, which may comprise e.g., the receiving port 1503 and the sending port 1504. The radio circuitry 1507 may be configured to set up and maintain at least a wireless connection with the first network node 111 , the second network node 112, the fourth network node 114, the device 130, and / or another structure in the communications network 100. Circuitry may be understood herein as a hardware component.

[0381] Hence, embodiments herein also relate to the third network node 113 comprising the processing circuitry 1501 and the memory 1502, said memory 1502 containing instructions executable by said processing circuitry 1501, whereby the third network node 113 is operative to perform the actions described herein in relation to the third network node 113, e.g., in Figure 4, and / or any of Figures 6-8.

[0382] Figure 16 depicts an example of the arrangement that the device 130 may comprise to perform the method actions described above in relation to Figure 5, and / or any of Figures 6-8 and / or Figure 10. The device 130 is for handling the first wireless device 131. The device 130 is configured to operate via the communications network 100.

[0383] Several embodiments are comprised herein. It should be noted that the examples herein are not mutually exclusive. One or more embodiments may be combined, where applicable. All possible combinations are not described to simplify the description. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments. The detailed description of some of the following corresponds to the same references provided above, in relation to the actions described for the device 130 and will thus not be repeated here. For example, the communications network 100 may be a 5G network.

[0384] The device 130 may be configured and / or operable to perform the sending in Action 501 , e.g. by means of a processing circuitry 1601 within the device 130 configured to, send the previous message to the first network node 111 configured to operate in the communications network 100. The previous message is configured to indicate the one or more L3 measurements.

[0385] The device 130 may be configured and / or operable to perform the receiving in Action 502, e.g. by means of the processing circuitry 1601 within the device 130 configured to, receive the another indication, from the second network node 112 configured to be managed by the first network node 111. The another indication is configured to instruct the device 130 to perform the one or more LTM procedures. The receiving of the another indication is configured to be based on the previous message configured to be sent.

[0386] The device 130 may be configured and / or operable to perform the receiving in Action 503, e.g. by means of the processing circuitry 1601 within the device 130 configured to, receive, based on the previous message configured to be sent, the fifth indication from the third network node 113 configured to operate in the communications network 100. The fifth indication may be configured to trigger the one or more LTM procedures.

[0387] In some embodiments, one or more of the following may apply: a) the first network node 111 may be configured to serve the device 130, b) the second network node 112 may be configured to serve the device 130, c) the first network node 111 may be configured to be the CU, d) the second network node 112 may be configured to be a DU, and e) the one or more LTM procedures may be configured to comprise one or more of: i) the LTM cell switch procedure from the first cell 121 to the second cell 122, ii) the early synchronization procedure, iii) the candidate TCI procedure, e.g., a candidate cell or beam TCI procedure, iv) the early uplink synchronization procedure, and v) the TA acquisition procedure.

[0388] The embodiments herein in the device 130 may be implemented through one or more processors, such as a processing circuitry 1601 in the device 130 depicted in Figure 16a, together with computer program code for performing the functions and actions of the embodiments herein. A processor, as used herein, may be understood to be a hardware component. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the embodiments herein when being loaded into the device 130. One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may furthermore be provided as pure program code on a server and downloaded to the device 130.

[0389] The processing circuitry 1601 may be configured to, or operable to, perform the method actions according to Figure 5, and / or any of Figures 6-8 and / or Figure 10.

[0390] The device 130 may further comprise a memory 1602 comprising one or more memory units. The memory 1602 is arranged to be used to store obtained information, store data, configurations, schedulings, and applications etc. to perform the methods herein when being executed in the device 130.

[0391] In some embodiments, the device 130 may receive information from, e.g., the first network node 111 , the second network node 112, the third network node 113, the fourth network node 114, and / or another structure in the communications network 100, through a receiving port 1603. In some embodiments, the receiving port 1603 may be, for example, connected to one or more antennas in device 130. In other embodiments, the device 130 may receive information from another structure in the communications network 100 through the receiving port 1603. Since the receiving port 1603 may be in communication with the processing circuitry 1601 , the receiving port 1603 may then send the received information to the processing circuitry 1601. The receiving port 1603 may also be configured to receive other information.

[0392] The processing circuitry 1601 in the device 130 may be further configured to transmit or send information to e.g., the first network node 111 , the second network node 112, the third network node 113, the fourth network node 114, and / or another structure in the communications network 100, through a sending port 1604, which may be in communication with the processing circuitry 1601, and the memory 1602.

[0393] Those skilled in the art will also appreciate that the processing circuitry 1601 described above may comprise a combination of analog and digital modules, and / or one or more processors configured with software and / or firmware, e.g., stored in memory, that, when executed by the one or more processors such as the processing circuitry 1601, perform as described above. One or more of these processors, as well as the other digital hardware, may be included in a single Application-Specific Integrated Circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a System-on-a-Chip (SoC).

[0394] Also, in some embodiments, the device 130 may be configured to perform the actions of Figure 5, and / or any of Figures 6-8 and / or Figure 10 with respective units that may be implemented as one or more applications running on one or more processors such as the processing circuitry 1601.

[0395] Also, in some embodiments, the first network node 111 may be configured to perform the actions of Figure 5, and / or any of Figures 6-8 and / or Figure 10 with respective units that may be implemented as one or more applications running on one or more processors such as the processing circuitry 1301.

[0396] Thus, the methods according to the embodiments described herein for the device 130 may be respectively implemented by means of a computer program 1605 product, comprising instructions, i.e. , software code portions, which, when executed on at least one processing circuitry 1601 , cause the at least one processing circuitry 1601 to carry out the actions described herein, as performed by the device 130. The computer program 1605 product may be stored on a computer-readable storage medium 1606. The computer-readable storage medium 1606, having stored thereon the computer program 1605, may comprise instructions which, when executed on at least one processing circuitry 1601, cause the at least one processing circuitry 1601 to carry out the actions described herein, as performed by the device 130. In some embodiments, the computer-readable storage medium 1606 may be a non- transitory computer-readable storage medium, such as a CD ROM disc, or a memory stick. In other embodiments, the computer program 1605 product may be stored on a carrier containing the computer program 1605 just described, wherein the carrier is one of an electronic signal, optical signal, radio signal, or the computer-readable storage medium 1606, as described above.

[0397] The device 130 may comprise a communication interface configured to facilitate communications between the device 130 and other nodes or devices, e.g., the first network node 111 , the second network node 112, the third network node 113, the fourth network node 114, and / or another structure in the communications network 100. The interface may, for example, include a transceiver configured to transmit and receive radio signals over an air interface in accordance with a suitable standard.

[0398] In other embodiments, the device 130 may also comprise a radio circuitry 1607, which may comprise e.g., the receiving port 1603 and the sending port 1604. The radio circuitry 1607 may be configured to set up and maintain at least a wireless connection with the first network node 111 , the second network node 112, the third network node 113, the fourth network node 114, and / or another structure in the communications network 100. Circuitry may be understood herein as a hardware component.

[0399] Hence, embodiments herein also relate to the device 130 comprising the processing circuitry 1601 and the memory 1602, said memory 1602 containing instructions executable by said processing circuitry 1601 , whereby the device 130 is operative to perform the actions described herein in relation to the device 130, e.g., in Figure 5, and / or any of Figures 6-8 and / or Figure 10.

[0400] Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and / or is implied from the context in which it is used. All references to a / an / the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and / or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following description.

[0401] As used herein, the expression “at least one of:” followed by a list of alternatives separated by commas, and wherein the last alternative is preceded by the “and” term, may be understood to mean that only one of the list of alternatives may apply, more than one of the list of alternatives may apply or all of the list of alternatives may apply. This expression may be understood to be equivalent to the expression “at least one of:” followed by a list of alternatives separated by commas, and wherein the last alternative is preceded by the “or” term.

[0402] EXAMPLES related to embodiments herein

[0403] The following are examples related to embodiments herein. Any of the features described in relation to Figures 17-20 may be combined with the actions of the examples related to embodiments herein, described in relation to 1-16.

[0404] The first network node 111 embodiments relate to Figure 17, Figures 6-9, Figures 11-13 and Figures 21-24.

[0405] A method, performed by a first network node, such as the first network node 111 is described herein. The method may be understood to be for handling mobility. The first network node 111 may be operating in a communications network, such as the communications network 100.

[0406] In some embodiments, the communications network 100 may support, or operate in, New Radio (NR).

[0407] The method may comprise one or more of the following actions. In particular examples, the method may comprise Action 205. In some embodiments, all the actions may be performed. One or more embodiments may be combined, where applicable. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments. All possible combinations are not described to simplify the description. A non-limiting example of the method performed by the first network node 111 is depicted in Figure 17. In Figure 17 optional actions in some embodiments may be represented with dashed lines. In some embodiments, the actions may be performed in a different order than that depicted Figure 17. o Sending 205 a first message. The first network node 111 may be configured and / or operable to perform the sending in this Action 205.

[0408] Sending may be to the second network node 112 operating in the communications network 100.

[0409] The first message may comprise a first indication, e.g., a first indicator. The first indication may indicate an L1 / L2-Triggered Mobility (LTM), e.g., one or more LTM procedures, for the device 130 operating in the communications network 100.

[0410] In some examples, one or more of the following may apply:

[0411] - the first network node 111 may serve the device 130,

[0412] - the second network node 112 may serve the device 130,

[0413] - the first network node 111 may be a Central Unit,

[0414] - the second network node 112 may be a Distributed Unit,

[0415] - the LTM may comprise one or more LTM procedures,

[0416] - the one or more LTM procedures may comprise one or more of: i. an LTM cell switch procedure from a first cell 121 to a second cell 122, ii. an early synchronization procedure, iii. a candidate Transmission Configuration Indication, TCI, procedure, iv. an early uplink synchronization procedure, and v. a Timing Advance (TA) acquisition procedure,

[0417] - the first message may be an F1AP message,

[0418] - the first message may be Class 1 UE associated signalling or a Class 2 UE associated signalling,

[0419] - the first message may indicate one or more target cells or beams,

[0420] - the first message may indicate one or more Layer 3 (L3) measurements performed by the device 130,

[0421] - the first message may request one or more Layer 1 (L1) measurements performed by the device 130,

[0422] - the first message may indicate a change in a triggering LTM cell switch decision for one or more candidate cells, - the first indication may be one of implicit and explicit,

[0423] - the first indication may be per candidate cell or for all candidate cells.

[0424] In some examples, one of the following may apply:

[0425] - the first message may indicate whether or not the one or more LTM procedures may be possible,

[0426] - the first message may indicate a request to initiate the one or more LTM procedures,

[0427] - the first message may indicate a preference to initiate the one or more LTM procedures,

[0428] - the first message may indicate a preference to initiate the one or more LTM procedures based on L3 measurements,

[0429] - the first message may indicate a preference to initiate the one or more LTM procedures based on L1 measurements,

[0430] - the first message may be a MEASUREMENT NOTIFICATION,

[0431] - the first message may be a UE CONTEXT SETUP REQUEST,

[0432] - the first message may be a UE CONTEXT MODIFICATION REQUEST,

[0433] - the first message may be a CU-DU Cell Switch Notification, and

[0434] - the first message may be a MEASUREMENT TRANSFER message.

[0435] In some embodiments, the method may further comprise one or more of the following actions: o Receiving 201 a previous message. The first network node 111 may be configured and / or operable to perform the receiving in this Action 201.

[0436] The receiving in this Action 201 may be from the device 130.

[0437] The previous message may indicate one or more L3 measurements. The sending in Action 205 of the first message may be based on the received previous message.

[0438] The previous message may be, e.g., a report, e.g., an L3 measurements report. o Determining 202 whether or not to initiate the LTM, e.g., the one or more

[0439] LTM procedures. The first network node 111 may be configured and / or operable to perform the determining in this Action 202.

[0440] Determining may be understood as calculating, deriving, dividing or similar.

[0441] The determining in this Action 202 may be based on the received previous message.

[0442] The sending in Action 205 of the first message may be based on a result of the determination.

[0443] In some examples, the determining in this Action 202 may be based on one or more of:

[0444] - failing to receive L1 measurements,

[0445] - a frequency of a carrier used,

[0446] - one or more conditions, - at least one property of the L3 measurements fulfilling a first condition,

[0447] - availability of specific L1 measurements, and

[0448] - availability of the specific L1 measurements for one cell. o Receiving 206 a second message. The first network node 111 may be configured and / or operable to perform the receiving in this Action 206.

[0449] The receiving in this Action 206 may be from the second network node 112.

[0450] The receiving in this Action 206 may be responsive to the sent first message.

[0451] The second message may indicate one of: i. whether or not the LTM, e.g., one or more LTM procedures, may have been initiated, e.g., that another indication has been sent to the device 130 instructing the device 130 to perform the LTM, e.g., LTM cell switch, and ii. that the LTM, e.g., LTM cell switch, is not allowed, and iii. whether or not L3 measurements are allowed to be used for execution of the LTM, e.g., LTM cell switch.

[0452] The second message may be, e.g., a UE Context Modification Response.

[0453] The another indication may be, e.g., a MAC CE command.

[0454] In some embodiments, the method may further comprise one or more of the following actions: o Sending 203 a second indication. The first network node 111 may be configured and / or operable to perform the sending in this Action 203.

[0455] The sending in this Action 203 may be to the third network node 113 operating in the communications network 100.

[0456] The second indication may request whether or not the one or more LTM procedures, e.g., LTM cell switch to one or more second cells 122, may be possible e.g., based on at least one of L1 and L3 measurements. The one or more second cells 122 may be served by the fourth network node 114 managed by the third network node 113.

[0457] The second indication may be e.g., a Bearer Context Modification Request. o Receiving 204 a third indication. The first network node 111 may be configured and / or operable to perform the receiving in this Action 204.

[0458] The receiving in this Action 204 may be from the third network node 113.

[0459] The receiving in this Action 204 may be responsive to the sent second indication.

[0460] The third indication may indicate whether or not (the) one or more LTM procedures, e.g., LTM cell switch to one or more second cells 122, may be possible, e.g., based on at least one of L1 and L3 measurements.

[0461] The third indication may be e.g., a Bearer Context Modification Response.

[0462] In Figure 17, optional units are indicated with dashed boxes. The first network node 111 may comprise an arrangement as shown in Figure 13 or in Figure 23.

[0463] The second network node 112 embodiments relate to Figure 18, Figures 6-8, Figures 10-12, Figure 14 and Figures 21-24.

[0464] A method, performed by a second network node, such as the second network node 112 is described herein. The method may be understood to be for handling mobility. The second network node 112 may be operating in a communications network, such as the communications network 100.

[0465] The method may comprise one or more of the following actions. In a particular nonlimiting example, Action 301 may be performed. In some embodiments, all the actions may be performed. One or more embodiments may be combined, where applicable. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments. All possible combinations are not described to simplify the description. A non-limiting example of the method performed by the second network node 112 is depicted in Figure 18. In Figure 18, optional actions in some embodiments may be represented with dashed lines.

[0466] The detailed description of some of the following corresponds to the same references provided above, in relation to the actions described for the first network node 111 and will thus not be repeated here to simplify the description. For example, the communications network 100 may support, or operate in, New Radio (NR). o Receiving 301 the first message. The second network node 112 may be configured and / or operable to perform the receiving in this Action 301.

[0467] The receiving in this Action 301 may be from the first network node 111 operating in the communications network 100.

[0468] The first message may comprise the first indication, e.g., a first indicator. The first indication may indicate the L1 / L2-Triggered Mobility (LTM), e.g., the one or more LTM procedures, for the device 130 operating in the communications network 100.

[0469] In some examples, one or more of the following may apply:

[0470] - the first network node 111 may serve the device 130,

[0471] - the second network node 112 may serve the device 130,

[0472] - the first network node 111 may be a Central Unit,

[0473] - the second network node 112 may be a Distributed Unit,

[0474] - the LTM may comprise the one or more LTM procedures,

[0475] - the one or more LTM procedures may comprise one or more of: i. the LTM cell switch procedure from the first cell 121 to the second cell 122, ii. the early synchronization procedure, iii. the candidate Transmission Configuration Indication, TCI, procedure, iv. the early uplink synchronization procedure, and v. the Timing Advance (TA) acquisition procedure,

[0476] - the first message may be the F1AP message,

[0477] - the first message may be Class 1 UE associated signalling or the Class 2 UE associated signalling,

[0478] - the first message may indicate the one or more target cells or beams,

[0479] - the first message may indicate the one or more Layer 3 (L3) measurements performed by the device 130,

[0480] - the first message may request the one or more Layer 1 (L1) measurements performed by the device 130,

[0481] - the first message may indicate the change in the triggering LTM cell switch decision for the one or more candidate cells,

[0482] - the first indication may be one of implicit and explicit,

[0483] - the first indication may be per candidate cell or for all candidate cells.

[0484] In some examples, one of the following may apply:

[0485] - the first message may indicate whether or not the one or more LTM procedures may be possible,

[0486] - the first message may indicate the request to initiate the one or more LTM procedures,

[0487] - the first message may indicate the preference to initiate the one or more LTM procedures,

[0488] - the first message may indicate the preference to initiate the one or more LTM procedures based on L3 measurements,

[0489] - the first message may indicate the preference to initiate the one or more LTM procedures based on L1 measurements,

[0490] - the first message may be the MEASUREMENT NOTIFICATION,

[0491] - the first message may be the UE CONTEXT SETUP REQUEST,

[0492] - the first message may be the UE CONTEXT MODIFICATION REQUEST,

[0493] - the first message may be the CU-DU Cell Switch Notification, and

[0494] - the first message may be the MEASUREMENT TRANSFER message.

[0495] In some embodiments, the method may further, or alternatively, comprise the following actions: o Receiving 302 a fourth indication. The second network node 112 may be configured and / or operable to perform the receiving in this Action 302.

[0496] The receiving in this Action 302 may be from the third network node 113 or the fourth network node 114 operating in the communications network 100.

[0497] The fourth indication may indicate whether or not the LTM, e.g., LTM cell switch, may be possible.

[0498] The fourth indication may be, e.g, an F1-LI message, for example, a DL USER DATA frame. o Determining 303 whether or not to initiate the LTM, e.g., whether or not to send another indication, e.g., to the device 130. The second network node 112 may be configured and / or operable to perform the determining in this Action 303.

[0499] The determining in this Action 303 may be based on at least one of the received first message and the received fourth indication.

[0500] The another indication may instruct the device 130 to perform the one or more LTM procedures, e.g., LTM cell switch. o Initiating 304 the LTM, e.g., the one or more LTM procedures, e.g., LTM cell switch. The second network node 112 may be configured and / or operable to perform the initiating in this Action 304.

[0501] Initiating may be understood as starting or triggering itself or, enabling or facilitating, that another entity may start or trigger.

[0502] The initiating in this Action 304 may be responsive to the received first message.

[0503] The initiating in this Action 304 may comprise sending the another indication to the device 130.

[0504] The initiating in this Action 304 may comprise sending the a sixth indication to the third network node 113, as will be described later. o Sending 305 the second message. The second network node 112 may be configured and / or operable to perform the sending in this Action 305.

[0505] The sending in this Action 305 may be responsive to the received first message.

[0506] The sending in this Action 305 may be to the first network node 111.

[0507] The second message, e.g., a UE CONTEXT MODIFICATION RESPONSE, may indicate one of: i. whether or not the LTM, e.g., the one or more LTM procedures, may have been initiated, e.g., that the another indication has been sent to the device 130 instructing the device 130 to perform the LTM, e.g., LTM cell switch, and ii. that the LTM, e.g., LTM cell switch, is not allowed, and iii. whether or not L3 measurements are allowed to be used for execution of the LTM, e.g., LTM cell switch.

[0508] In Figure 18, optional units are indicated with dashed boxes.

[0509] The second network node 112 may comprise an arrangement as shown in Figure 14 or in Figure 23.

[0510] The first source first network node 111 embodiments relate to Figure 19, Figures 6-8, Figure 15 and Figures 21-24.

[0511] A method, performed by a third network node, such as the third network node 113 is described herein. The method may be understood to be for handling mobility. The third network node 113 may be operating in a communications network, such as the communications network 100.

[0512] The method may comprise one or more of the following actions. In a particular nonlimiting example, Action 401 may be performed. In another particular non-limiting example, Action 401 and Action 402 may be performed. In some embodiments, all the actions may be performed. One or more embodiments may be combined, where applicable. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments. All possible combinations are not described to simplify the description. A non-limiting example of the method performed by the third network node 113 is depicted in Figure 19. In Figure 19, optional actions in some embodiments may be represented with dashed lines.

[0513] The detailed description of some of the following corresponds to the same references provided above, in relation to the actions described for the first network node 111 and will thus not be repeated here to simplify the description. For example, the communications network 100 may support, or operate in, New Radio (NR). o Receiving 401 the second indication. The third network node 113 may be configured and / or operable to perform the receiving in this Action 401.

[0514] The receiving in this Action 401 of the second indication may be from the first network node 111 operating in the communications network 100.

[0515] The second indication may request whether or not the one or more LTM procedures, e.g., LTM cell switch to the one or more second cells 122 for the device 130 operating in the communications network 100, may be possible e.g., based on at least one of L1 and L3 measurements. The one or more second cells 122 may be served by the fourth network node 114 managed by the third network node 113. o Sending 402 the third indication. The third network node 113 may be configured and / or operable to perform the sending in this Action 402. The sending in this Action 402 may be to the first network node 111.

[0516] The sending in this Action 402 may be responsive to the received second indication.

[0517] The third indication may indicate whether or not (the) one or more LTM procedures, e.g., LTM cell switch to one or more second cells 122, may be possible, e.g., based on at least one of L1 and L3 measurements.

[0518] The third indication may indicate whether or not the one or more LTM procedures, e.g., the LTM cell switch to one or more second cells 122, may be possible, e.g., based on at least one of L1 and L3 measurements.

[0519] In some embodiments, the method may further, or alternatively, comprise the following actions: o Sending 403 the fourth indication. The third network node 113 may be configured and / or operable to perform the sending in this Action 403.

[0520] The sending in this Action 403 may be to the second network node 112.

[0521] The fourth indication may indicate whether or not the LTM, e.g., the one or more LTM procedures, e.g., LTM cell switch, is possible. o Sending 404 a fifth indication. The third network node 113 may be configured and / or operable to perform the sending in this Action 404.

[0522] The sending in this Action 404 may be to the device 130.

[0523] The sending in this Action 404 may be based on the received second indication.

[0524] The fifth indication may trigger the one or more LTM procedures.

[0525] The fifth indication may be, e.g., a MAC CE.

[0526] In some examples, one or more of the following may apply:

[0527] - the first network node 111 may serve the device 130,

[0528] - the third network node 113 may be a candidate to serve the device 130,

[0529] - the first network node 111 may be a Central Unit,

[0530] - the third network node 113 may be another CU,

[0531] - the one or more LTM procedures may comprise one or more of: i. the LTM cell switch procedure from the first cell 121 to the second cell 122, ii. the early synchronization procedure, iii. the candidate Transmission Configuration Indication, TCI, procedure, iv. the early uplink synchronization procedure, and v. the Timing Advance (TA) acquisition procedure,

[0532] In Figure 19, optional units are indicated with dashed boxes.

[0533] The third network node 113 may comprise an arrangement as shown in Figure 15 or in Figure 23. The device 130 embodiments relate to Figure 20, Figures 6-8, Figure 10, Figure 16 and Figures 21-24.

[0534] A method, performed by a second network node, such as the device 130 is described herein. The method may be understood to be for handling mobility. The device 130 may be operating in a communications network, such as the communications network 100.

[0535] The method may comprise one or more of the following actions. In a particular nonlimiting example, Action 501 may be performed. In another particular non-limiting example, Action 501 and Action 502 may be performed. In some embodiments, all the actions may be performed. One or more embodiments may be combined, where applicable. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments. All possible combinations are not described to simplify the description. A non-limiting example of the method performed by the device 130 is depicted in Figure 20. In Figure 20, optional actions in some embodiments may be represented with dashed lines.

[0536] The detailed description of some of the following corresponds to the same references provided above, in relation to the actions described for the first network node 111 and will thus not be repeated here to simplify the description. For example, the communications network 100 may support, or operate in, New Radio (NR). o Sending 501 the previous message. The device 130 may be configured and / or operable to perform the sending in this Action 501.

[0537] The sending in this Action 501 may be to the first network node 111 operating in the communications network 100.

[0538] The previous message may indicate the one or more L3 measurements.

[0539] In some examples, one or more of the following may apply:

[0540] - the first network node 111 may serve the device 130,

[0541] - the second network node 112 may serve the device 130,

[0542] - the first network node 111 may be a Central Unit,

[0543] - the second network node 112 may be a Distributed Unit,

[0544] - the one or more LTM procedures may comprise one or more of: i. the LTM cell switch procedure from the first cell 121 to the second cell 122, ii. the early synchronization procedure, iii. the candidate Transmission Configuration Indication, TCI, procedure, iv. the early uplink synchronization procedure, and v. the Timing Advance (TA) acquisition procedure. In some embodiments, the method may further, or alternatively, comprise the following action: o Receiving 502 the another indication. The device 130 may be configured and / or operable to perform the receiving in this Action 502.

[0545] The receiving in this Action 502 may be from the second network node 112 managed by the first network node 111.

[0546] The another indication may instruct the device 130 to perform the one or more LTM procedures, e.g., LTM cell switch. The receiving in this Action 502 of the another indication may be based on the sent previous message.

[0547] In some embodiments, the method may further, or alternatively, comprise the following action: o Receiving 503 the fifth indication. The device 130 may be configured and / or operable to perform the receiving in this Action 503.

[0548] The receiving in this Action 503 may be based on the sent previous message.

[0549] The receiving in this Action 503 may be from the third network node 113 operating in the communications network 100.

[0550] The fifth indication may trigger the one or more LTM procedures.

[0551] In Figure 20, optional units are indicated with dashed boxes.

[0552] The device 130 may comprise an arrangement as shown in Figure 16 or in Figure 22.

[0553] Selected examples of embodiments herein may be as follows.

[0554] EXAMPLE 1. A method performed by a first network node (111), the method being for handling mobility, the first network node (111) operating in a communications network (100), and the method comprising:

[0555] - sending (205) a first message to a second network node (112) operating in the communications network (100), the first message comprising a first indication indicating an L1 / L2-Triggered Mobility, LTM, e.g., one or more LTM procedures, for a device (130) operating in the communications network (100).

[0556] EXAMPLE 2. The method according to example 1, wherein one or more of:

[0557] - the first network node (111) serves the device (130),

[0558] - the second network node (112) serves the device (130),

[0559] - the first network node (111) is a Central Unit,

[0560] - the second network node (112) is a Distributed Unit,

[0561] - the LTM comprises one or more LTM procedures,

[0562] - the one or more LTM procedures comprise one or more of: i. an LTM cell switch procedure from a first cell (121) to a second cell (122), ii. an early synchronization procedure, iii. a candidate Transmission Configuration Indication, TCI, procedure, iv. an early uplink synchronization procedure, and v. a Timing Advance, TA, acquisition procedure,

[0563] - the first message is an F1AP message,

[0564] - the first message is Class 1 UE associated signalling or a Class 2 UE associated signalling,

[0565] - the first message indicates one or more target cells or beams,

[0566] - the first message indicates one or more Layer 3, L3, measurements performed by the device (130),

[0567] - the first message requests one or more Layer 1 , L1 , measurements performed by the device (130),

[0568] - the first message indicates a change in a triggering LTM cell switch decision for one or more candidate cells,

[0569] - the first indication is one of implicit and explicit,

[0570] - the first indication is per candidate cell or for all candidate cells.

[0571] EXAMPLE 3. The method according to any of examples 1-2, further comprising one or more of:

[0572] - receiving (201) a previous message from the device (130), the previous message indicating one or more L3 measurements, wherein the sending (205) of the first message is based on the received previous message,

[0573] - determining (202), based on the received previous message, whether or not to initiate the LTM, and wherein the sending (205) of the first message is based on a result of the determination, and

[0574] - receiving (206), responsive to the sent first message, a second message from the second network node (112), the second message indicating one of: i. whether or not the LTM, e.g., one or more LTM procedures, has been initiated, e.g., that another indication has been sent to the device (130) instructing the device (130) to perform the LTM, e.g., LTM cell switch, and ii. that the LTM, e.g., LTM cell switch, is not allowed, and iii. whether or not L3 measurements are allowed to be used for execution of the LTM, e.g., LTM cell switch.

[0575] EXAMPLE 4. The method according to examples 2 and 3, further comprising:

[0576] - sending (203) a second indication to a third network node (113) operating in the communications network (100), the second indication requesting whether or not the one or more LTM procedures, e.g., LTM cell switch to one or more second cells (122), are possible e.g., based on at least one of L1 and L3 measurements, the one or more second cells (122) being served by a fourth network node (114) managed by the third network node (113),

[0577] - receiving (204), responsive to the sent second indication, a third indication from the third network node (113), the third indication indicating whether or not one or more LTM procedures, e.g., LTM cell switch to one or more second cells (122), are possible, e.g., based on at least one of L1 and L3 measurements.

[0578] EXAMPLE 5. The method according to any of examples 3-4, wherein the determining (202) is based on one or more of:

[0579] - failing to receive Layer 1 , L1, measurements,

[0580] - a frequency of a carrier used,

[0581] - one or more conditions,

[0582] - at least one property of the L3 measurements fulfilling a first condition,

[0583] - availability of specific L1 measurements, and

[0584] - availability of the specific L1 measurements for one cell.

[0585] EXAMPLE 6. The method according to any of examples 2-4, wherein one of:

[0586] - the first message indicates whether or not the one or more LTM procedures are possible,

[0587] - the first message indicates a request to initiate the one or more LTM procedures,

[0588] - the first message indicates a preference to initiate the one or more LTM procedures,

[0589] - the first message indicates a preference to initiate the one or more LTM procedures based on L3 measurements,

[0590] - the first message indicates a preference to initiate the one or more LTM procedures based on L1 measurements,

[0591] - the first message is a MEASUREMENT NOTIFICATION,

[0592] - the first message is a UE CONTEXT SETUP REQUEST,

[0593] - the first message is a UE CONTEXT MODIFICATION REQUEST,

[0594] - the first message is a CU-DU Cell Switch Notification, and

[0595] - the first message is a MEASUREMENT TRANSFER message.

[0596] EXAMPLE 7. A method performed by a second network node (112), the method being for handling mobility, the second network node (112) operating in a communications network (100), and the method comprising: - receiving (301) a first message from a first network node (111) operating in the communications network (100), the first message comprising a first indication indicating an L1 / L2-Triggered Mobility, LTM, e.g., one or more LTM procedures, for a device (130) operating in the communications network (100).

[0597] EXAMPLE 8. The method according to example 7, wherein one or more of:

[0598] - the first network node (111) serves the device (130),

[0599] - the second network node (112) serves the device (130),

[0600] - the first network node (111) is a Central Unit,

[0601] - the second network node (112) is a Distributed Unit,

[0602] - the LTM comprises one or more LTM procedures,

[0603] - the one or more LTM procedures comprise one or more of: i. an LTM cell switch procedure from a first cell (121) to a second cell (122), ii. an early synchronization procedure, iii. a candidate Transmission Configuration Indication, TCI, procedure, iv. an early uplink synchronization procedure, and v. a Timing Advance, TA, acquisition procedure,

[0604] - the first message is an F1AP message,

[0605] - the first message is Class 1 UE associated signalling or a Class 2 UE associated signalling,

[0606] - the first message indicates one or more target cells or beams,

[0607] - the first message indicates one or more Layer 3, L3, measurements performed by the device (130),

[0608] - the first message requests one or more Layer 1 , L1 , measurements performed by the device (130),

[0609] - the first message indicates a change in a triggering LTM cell switch decision for one or more candidate cells,

[0610] - the first indication is one of implicit and explicit,

[0611] - the first indication is per candidate cell or for all candidate cells.

[0612] EXAMPLE 9. The method according to any of examples 7-8, wherein one of:

[0613] - the first message indicates whether or not the one or more LTM procedures are possible,

[0614] - the first message indicates a request to initiate the one or more LTM procedures,

[0615] - the first message indicates a preference to initiate the one or more LTM procedures, - the first message indicates a preference to initiate the one or more LTM procedures based on L3 measurements,

[0616] - the first message indicates a preference to initiate the one or more LTM procedures based on L1 measurements,

[0617] - the first message is a MEASUREMENT NOTIFICATION,

[0618] - the first message is a UE CONTEXT SETUP REQUEST,

[0619] - the first message is a UE CONTEXT MODIFICATION REQUEST,

[0620] - the first message is a CU-DU Cell Switch Notification, and

[0621] - the first message is a MEASUREMENT TRANSFER message.

[0622] EXAMPLE 10. The method according to any of examples 8-9, further comprising one or more one of:

[0623] - receiving (302) from a third network node (113) or a fourth network node (114) operating in the communications network (100), a fourth indication indicating whether or not the LTM, e.g., LTM cell switch, is possible.

[0624] - determining (303), based on at least one of the received first message and the received fourth indication, whether or not to initiate the LTM, e.g., whether or not to send another indication to the device (130), the another indication instructing the device (130) to perform the one or more LTM procedures, e.g., LTM cell switch,

[0625] - initiating (304), responsive to the received first message, the LTM, e.g., the one or more LTM procedures, e.g., LTM cell switch, and

[0626] - sending (305), responsive to the received first message, a second message to the first network node (111), the second message, e.g., a UE CONTEXT MODIFICATION RESPONSE, indicating one of: i. whether or not the LTM, e.g., one or more LTM procedures, has been initiated, e.g., that another indication has been sent to the device (130) instructing the device (130) to perform the LTM, e.g., LTM cell switch, and ii. that the LTM, e.g., LTM cell switch, is not allowed, and iii. whether or not L3 measurements are allowed to be used for execution of the LTM, e.g., LTM cell switch.

[0627] EXAMPLE 11. A method performed by a third network node (113), the method being for handling mobility, the third network node (113) operating in a communications network (100), and the method comprising:

[0628] - receiving (401) a second indication from a first network node (111) operating in the communications network (100), the second indication requesting whether or not one or more L1 / L2-Triggered Mobility, LTM, procedures, e.g., LTM cell switch to one or more second cells (122) for a device (130) operating in the communications network (100), are possible, e.g., based on at least one of L1 and L3 measurements, the one or more second cells (122) being served by a fourth network node (114) managed by the third network node (113), and

[0629] - sending (402), responsive to the received second indication, a third indication to the first network node (111), the third indication indicating whether or not the one or more LTM procedures, e.g., the LTM cell switch to one or more second cells (122), are possible, e.g., based on at least one of L1 and L3 measurements.

[0630] EXAMPLE 12. The method according to example 11 , further comprising one or more of:

[0631] - sending (403) to a second network node (112) operating in the communications network (100), a fourth indication indicating whether or not the one or more LTM procedures, e.g., LTM cell switch, is possible, and

[0632] - sending (404), based on the received second indication, a fifth indication to the device (130), the fifth indication triggering the one or more LTM procedures.

[0633] EXAMPLE 13. The method according to any of examples 11-12, wherein one or more of:

[0634] - the first network node (111) serves the device (130),

[0635] - the third network node (113) is a candidate to serve the device (130),

[0636] - the first network node (111) is a Central Unit, CU,

[0637] - the third network node (113) is another CU, and

[0638] - the one or more LTM procedures comprise one or more of: i. an LTM cell switch procedure from a first cell (121) to a second cell (122), ii. an early synchronization procedure, iii. a candidate Transmission Configuration Indication, TCI, procedure, iv. an early uplink synchronization procedure, and v. a Timing Advance, TA, acquisition procedure,

[0639] EXAMPLE 14. A method performed by a device (130), the method being for handling mobility, the device (130) operating in a communications network (100), and the method comprising:

[0640] - sending (501) a previous message to a first network node (111) operating in the communications network (100), the previous message indicating one or more L3 measurements, and

[0641] - receiving (502) another indication, e.g., from a second network node (112) managed by the first network node (111), the another indication instructing the device (130) to perform one or more L1 / L2-Triggered Mobility, LTM, procedures, e.g., LTM cell switch, wherein the receiving (502) of the another indication is based on the sent previous message.

[0642] EXAMPLE 15. The method according to example 14, further comprising:

[0643] - receiving (503), based on the sent previous message, a fifth indication from a third network node (113) operating in the communications network (100), the fifth indication triggering the one or more LTM procedures.

[0644] EXAMPLE 16. The method according to any of examples 14-15, wherein one or more of:

[0645] - the first network node (111) serves the device (130),

[0646] - the second network node (112) serves the device (130),

[0647] - the first network node (111) is a Central Unit,

[0648] - the second network node (112) is a Distributed Unit, and

[0649] - the one or more LTM procedures comprise one or more of: i. an LTM cell switch procedure from a first cell (121) to a second cell (122), ii. an early synchronization procedure, iii. a candidate Transmission Configuration Indication, TCI, procedure, iv. an early uplink synchronization procedure, and v. a Timing Advance, TA, acquisition procedure.

[0650] Further Extensions And Variations

[0651] Figure 21 shows an example of a communication system 2100 in accordance with some embodiments.

[0652] In the example, the communication system 2100, such as the wireless communications network 100, includes a telecommunication network 2102 that includes an access network 2104, such as a radio access network (RAN), and a core network 2106, which includes one or more core network nodes 2108, such as the network node 112, e.g., the second network node 112, in some examples. The access network 2104 includes one or more access network nodes, such as, e.g., the first network node 111 , the second network node 112, the third network node 113 and / or the fourth network node 114, in other examples, such as network nodes 2110a and 2110b (one or more of which may be generally referred to as network nodes 2110), or any other similar 3rdGeneration Partnership Project (3GPP) access nodes or non-3GPP access points. Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunication network 2102 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network 2102 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in the telecommunication network2102, including one or more network nodes 2110 and / or core network nodes 2108.

[0653] Examples of an ORAN network node include an open radio unit (0-Rll), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O-CU-CP) or an O- Cll user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non- real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an A1 , F1 , W1 , E1 , E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an O-2 interface defined by the O- RAN Alliance or comparable technologies. The network nodes 2110 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 2112a, 2112b, 2112c, and 2112d (one or more of which may be generally referred to as UEs 2112) to the core network 2106 over one or more wireless connections. Any of the UEs 2112a, 2112b, 2112c, and 2112d are examples of the device 130.

[0654] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 2100 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. The communication system 2100 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0655] The device 130, exemplified in Figure 21 as the UEs 2112 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with any of the first network node 111 , the second network node 112, the third network node 113 and / or the fourth network node 114, exemplified in Figure 21 as network nodes 2110 and other communication devices. Similarly, the network nodes 2110 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs 2112 and / or with other network nodes or equipment in the telecommunication network 2102 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunication network 2102.

[0656] In the depicted example, the core network 2106 connects the network nodes 2110 to one or more host computing systems, such as host 2116. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 2106 includes one more core network nodes (e.g., core network node 2108) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 2108. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier Deconcealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0657] The host 2116 may be under the ownership or control of a service provider other than an operator or provider of the access network 2104 and / or the telecommunication network 2102. The host 2116 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0658] As a whole, the communication system 2100 of Figure 21 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox. In some examples, the telecommunication network 2102 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 2102 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 2102. For example, the telecommunications network 2102 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC) / Massive loT services to yet further UEs.

[0659] In some examples, the UEs 2112 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 2104 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 2104. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

[0660] In the example, the hub 2114 communicates with the access network 2104 to facilitate indirect communication between one or more UEs (e.g., UE 2112c and / or 2112d) and network nodes (e.g., network node 2110b). In some examples, the hub 2114 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 2114 may be a broadband router enabling access to the core network 2106 for the UEs. As another example, the hub 2114 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 2110, or by executable code, script, process, or other instructions in the hub 2114. As another example, the hub 2114 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 2114 may be a content source. For example, for a UE that is a VR device, display, loudspeaker, or other media delivery device, the hub 2114 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 2114 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 2114 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0661] The hub 2114 may have a constant / persistent or intermittent connection to the network node 2110b. The hub 2114 may also allow for a different communication scheme and / or schedule between the hub 2114 and UEs (e.g., UE 2112c and / or 2112d), and between the hub 2114 and the core network 2106. In other examples, the hub 2114 is connected to the core network 2106 and / or one or more UEs via a wired connection. Moreover, the hub 2114 may be configured to connect to an M2M service provider over the access network 2104 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 2110 while still connected via the hub 2114 via a wired or wireless connection. In some embodiments, the hub 2114 may be a dedicated hub - that is, a hub whose primary function is to route communications to / from the UEs from / to the network node 2110b. In other embodiments, the hub 2114 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 2110b, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0662] Figure 22 shows a UE 2200 in accordance with some embodiments. The UE 2200 presents additional details of some embodiments of the UE 2112 of Figure 1 . As used herein, a UE refers to a device capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage / playback device, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), an Augmented Reality (AR) or Virtual Reality (VR) device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by the 3rd Generation Partnership Project (3GPP), including a narrow band internet of things (NB-loT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0663] A UE may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0664] The UE 2200 includes processing circuitry 2202 that is operatively coupled via a bus 2204 to an input / output interface 2206, a power source 2208, a memory 2210, a communication interface 2212, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 22. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc. The processing circuitry 2202 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 2210. The processing circuitry 2202 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 2202 may include multiple central processing units (CPUs).

[0665] In the example, the input / output interface 2206 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 2200. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0666] In some embodiments, the power source 2208 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 2208 may further include power circuitry for delivering power from the power source 2208 itself, and / or an external power source, to the various parts of the UE 2200 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 2208. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 2208 to make the power suitable for the respective components of the UE 2200 to which power is supplied.

[0667] The memory 2210 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 2210 includes one or more application programs 2214, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 2216. The memory 2210 may store, for use by the UE 2200, any of a variety of various operating systems or combinations of operating systems.

[0668] The memory 2210 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUlCC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ The memory 2210 may allow the UE 2200 to access instructions, application programs and the like, stored on transitory or non- transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in the memory 2210, which may be or comprise a device-readable storage medium.

[0669] The processing circuitry 2202 may be configured to communicate with an access network or other network using the communication interface 2212. The communication interface 2212 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 2222. The communication interface 2212 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 2218 and / or a receiver 2220 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 2218 and receiver 2220 may be coupled to one or more antennas (e.g., antenna 2222) and may share circuit components, software or firmware, or alternatively be implemented separately.

[0670] In the illustrated embodiment, communication functions of the communication interface 2212 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and / or standards, such as IEEE 802.11 , Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / internet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QIIIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0671] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 2212, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0672] As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0673] A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to the UE 2200 shown in Figure 22.

[0674] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements, and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-loT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0675] In practice, any number of UEs may be used together with respect to a single example. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g. by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

[0676] Figure 23 shows a network node 2300 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and / or operable to communicate directly or indirectly with a UE and / or with other network nodes or equipment, in a telecommunication network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)), O-RAN nodes or components of an O-RAN node (e.g., O-RU, O-DU, O-CU).

[0677] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an O-RAN access node) and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0678] Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell / multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0679] The network node 2300 includes a processing circuitry 2302, a memory 2304, a communication interface 2306, and a power source 2308. The network node 2300 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 2300 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 2300 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 2304 for different RATs) and some components may be reused (e.g., a same antenna 2310 may be shared by different RATs). The network node 2300 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 2300, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 2300.

[0680] The processing circuitry 2302 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other network node 2300 components, such as the memory 2304, to provide network node 2300 functionality.

[0681] In some embodiments, the processing circuitry 2302 includes a system on a chip (SOC). In some embodiments, the processing circuitry 2302 includes one or more of radio frequency (RF) transceiver circuitry 2312 and baseband processing circuitry 2314. In some embodiments, the radio frequency (RF) transceiver circuitry 2312 and the baseband processing circuitry 2314 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 2312 and baseband processing circuitry 2314 may be on the same chip or set of chips, boards, or units.

[0682] The memory 2304 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 2302. The memory 2304 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 2302 and utilized by the network node 2300. The memory 2304 may be used to store any calculations made by the processing circuitry 2302 and / or any data received via the communication interface 2306. In some embodiments, the processing circuitry 2302 and memory 2304 is integrated.

[0683] The communication interface 2306 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, the communication interface 2306 comprises port(s) / terminal(s) 2316 to send and receive data, for example to and from a network over a wired connection. The communication interface 2306 also includes radio front-end circuitry 2318 that may be coupled to, or in certain embodiments a part of, the antenna 2310. Radio front-end circuitry 2318 comprises filters 2320 and amplifiers 2322. The radio front-end circuitry 2318 may be connected to an antenna 2310 and processing circuitry 2302. The radio front-end circuitry may be configured to condition signals communicated between antenna 2310 and processing circuitry 2302. The radio front-end circuitry 2318 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 2318 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 2320 and / or amplifiers 2322. The radio signal may then be transmitted via the antenna 2310. Similarly, when receiving data, the antenna 2310 may collect radio signals which are then converted into digital data by the radio front-end circuitry 2318. The digital data may be passed to the processing circuitry 2302. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0684] In certain alternative embodiments, the network node 2300 does not include separate radio front-end circuitry 2318, instead, the processing circuitry 2302 includes radio front-end circuitry and is connected to the antenna 2310. Similarly, in some embodiments, all or some of the RF transceiver circuitry 2312 is part of the communication interface 2306. In still other embodiments, the communication interface 2306 includes one or more ports or terminals 2316, the radio frontend circuitry 2318, and the RF transceiver circuitry 2312, as part of a radio unit (not shown), and the communication interface 2306 communicates with the baseband processing circuitry 2314, which is part of a digital unit (not shown).

[0685] The antenna 2310 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 2310 may be coupled to the radio front-end circuitry 2318 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 2310 is separate from the network node 2300 and connectable to the network node 2300 through an interface or port.

[0686] The antenna 2310, communication interface 2306, and / or the processing circuitry 2302 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node. Any information, data and / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, the antenna 2310, the communication interface 2306, and / or the processing circuitry 2302 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment.

[0687] The power source 2308 provides power to the various components of network node 2300 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 2308 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 2300 with power for performing the functionality described herein. For example, the network node 2300 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 2308. As a further example, the power source 2308 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0688] Embodiments of the network node 2300 may include additional components beyond those shown in Figure 23 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, the network node 2300 may include user interface equipment to allow input of information into the network node 2300 and to allow output of information from the network node 2300. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 2300. In some embodiments providing a core network node, such as core network node 108 of FIG. 21 , some components, such as the radio front-end circuitry 2318 and the RF transceiver circuitry 2312 may be omitted.

[0689] Figure 24 is a block diagram illustrating a virtualization environment 2400 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 2400 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 2400 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an 0-2 interface. Virtualization may facilitate distributed implementations of a network node, UE, core network node, or host.

[0690] Applications 2402 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment Q400 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.

[0691] Hardware 2404 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices as described herein, such as a network interface, input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 2406 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 2408a and 2408b (one or more of which may be generally referred to as VMs 2408), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. The virtualization layer 2406 may present a virtual operating platform that appears like networking hardware to the VMs 2408.

[0692] The VMs 2408 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 2406. Different embodiments of the instance of a virtual appliance 2402 may be implemented on one or more of VMs 2408, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[0693] In the context of NFV, a VM 2408 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs 2408, and that part of hardware 2404 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 2408 on top of the hardware 2404 and corresponds to the application 2402.

[0694] Hardware 2404 may be implemented in a standalone network node with generic or specific components. Hardware 2404 may implement some functions via virtualization. Alternatively, hardware 2404 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 2410, which, among others, oversees lifecycle management of applications 2402. In some embodiments, hardware 2404 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 2412 which may alternatively be used for communication between hardware nodes and radio units.

[0695] Although the computing devices described herein (e.g., UEs, network nodes) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and / or software needed to perform the tasks, features, functions and methods disclosed herein. Determining, calculating, obtaining or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and / or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and / or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

[0696] The first network node 111 embodiments relate to Figure 2, Figures 6-9, Figures 11-13 and Figures 21 , 23-24.

[0697] The first network node 111 may comprise an arrangement as shown in Figure 13 or in Figure 23.

[0698] The second network node 112 embodiments relate to Figure 3, Figures 6-8, Figures IQ- 12, Figure 14 and Figures 21 , 23-24.

[0699] The second network node 112 may comprise an arrangement as shown in Figure 14 or in Figure 23.

[0700] The third network node 113 embodiments relate to Figure 4, Figures 6-8, Figure 15 and Figures 21 , 23-24. The third network node 113 may comprise an arrangement as shown in Figure 15 or in Figure 23.

[0701] The device 130 embodiments relate to Figure 5, Figures 6-8, Figure 10, Figure 16 and Figures 21-22, 24.

[0702] The device 130 may comprise an arrangement as shown in Figure 16 or in Figure 22.

[0703] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer-readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device- readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer-readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole, and / or by end users and a wireless network generally.

[0704] REFERENCES

[0705] 1. RP-233970, 3GPP WID: Further NR mobility enhancements.

[0706] 2. TS 38.473 v18.2.0, 3GPP F1AP specification.

[0707] 3. TS 38.300 v18.2.0, 3GPP NR and NG-RAN Overall Description, stage-2 .

[0708] 4. TS 38.401 v18.2.0, 3GPP NG-RAN; Architecture description, stage-2.

[0709] 5. TS 37.483 v18.2.0, 3GPP E1AP specification.

[0710] 6. TS 38.425 v18.1.0, 3GPP NR User Plane Protocol specification.

Claims

CLAIMS:

1. A method performed by a first network node (111), the method being for handling mobility, the first network node (111) operating in a communications network (100), and the method comprising:- sending (205) a first message to a second network node (112) operating in the communications network (100), the first message comprising a first indication indicating one or more L1 / L2-Triggered Mobility, LTM, procedures for a device (130) operating in the communications network (100), wherein the first message indicates one or more target cells or beams.

2. The method according to claim 1, wherein one or more of:- the first network node (111) serves the device (130),- the second network node (112) serves the device (130),- the first network node (111) is a Central Unit,- the second network node (112) is a Distributed Unit,- the one or more LTM procedures comprise one or more of: i. an LTM cell switch procedure from a first cell (121) to a second cell (122), ii. an early synchronization procedure, iii. a candidate Transmission Configuration Indication, TCI, procedure, iv. an early uplink synchronization procedure, and v. a Timing Advance, TA, acquisition procedure,- the first message is an F1AP message,- the first message is Class 1 UE associated signalling or a Class 2 UE associated signalling,- the first message indicates one or more Layer 3, L3, measurements performed by the device (130),- the first message requests one or more Layer 1 , L1 , measurements performed by the device (130),- the first message indicates a change in a triggering LTM cell switch decision for one or more candidate cells,- the first indication is one of implicit and explicit, and- the first indication is per candidate cell or for all candidate cells.

3. The method according to any of claims 1-2, further comprising one or more of:- receiving (201) a previous message from the device (130), the previous message indicating one or more L3 measurements, wherein the sending (205) of the first message is based on the received previous message,- determining (202), based on the received previous message, whether or not to initiate the one or more LTM procedures, and wherein the sending (205) of the first message is based on a result of the determination, and- receiving (206), responsive to the sent first message, a second message from the second network node (112), the second message indicating one of: i. whether or not the one or more LTM procedures have been initiated, ii. that the LTM is not allowed, and iii. whether or not L3 measurements are allowed to be used for execution of the LTM.

4. The method according to claims 2 and 3, further comprising:- sending (203) a second indication to a third network node (113) operating in the communications network (100), the second indication requesting whether or not the one or more LTM procedures are possible, and- receiving (204), responsive to the sent second indication, a third indication from the third network node (113), the third indication indicating whether or not one or more LTM procedures are possible.

5. The method according to any of claims 3-4, wherein the determining (202) is based on one or more of:- failing to receive Layer 1 , L1, measurements,- a frequency of a carrier used,- one or more conditions,- at least one property of the L3 measurements fulfilling a first condition,- availability of specific L1 measurements, and- availability of the specific L1 measurements for one cell.

6. The method according to any of claims 2-4, wherein one of:- the first message indicates whether or not the one or more LTM procedures are possible,- the first message indicates a request to initiate the one or more LTM procedures,- the first message indicates a preference to initiate the one or more LTM procedures,- the first message indicates a preference to initiate the one or more LTM procedures based on L3 measurements,- the first message indicates a preference to initiate the one or more LTM procedures based on L1 measurements,- the first message is a MEASUREMENT NOTIFICATION,- the first message is a UE CONTEXT SETUP REQUEST,- the first message is a UE CONTEXT MODIFICATION REQUEST,- the first message is a CU-DU Cell Switch Notification, and- the first message is a MEASUREMENT TRANSFER message.

7. A method performed by a second network node (112), the method being for handling mobility, the second network node (112) operating in a communications network (100), and the method comprising:- receiving (301) a first message from a first network node (111) operating in the communications network (100), the first message comprising a first indication indicating one or more L1 / L2-Triggered Mobility, LTM, procedures, for a device (130) operating in the communications network (100), wherein the first message indicates one or more target cells or beams.

8. The method according to claim 7, wherein one or more of:- the first network node (111) serves the device (130),- the second network node (112) serves the device (130),- the first network node (111) is a Central Unit,- the second network node (112) is a Distributed Unit,- the one or more LTM procedures comprise one or more of: i. an LTM cell switch procedure from a first cell (121) to a second cell (122), ii. an early synchronization procedure, iii. a candidate Transmission Configuration Indication, TCI, procedure, iv. an early uplink synchronization procedure, and v. a Timing Advance, TA, acquisition procedure,- the first message is an F1AP message,- the first message is Class 1 UE associated signalling or a Class 2 UE associated signalling,- the first message indicates one or more Layer 3, L3, measurements performed by the device (130),- the first message requests one or more Layer 1 , L1 , measurements performed by the device (130),- the first message indicates a change in a triggering LTM cell switch decision for one or more candidate cells,- the first indication is one of implicit and explicit, and- the first indication is per candidate cell or for all candidate cells.

9. The method according to any of claims 7-8, wherein one of:- the first message indicates whether or not the one or more LTM procedures are possible,- the first message indicates a request to initiate the one or more LTM procedures,- the first message indicates a preference to initiate the one or more LTM procedures,- the first message indicates a preference to initiate the one or more LTM procedures based on L3 measurements,- the first message indicates a preference to initiate the one or more LTM procedures based on L1 measurements,- the first message is a MEASUREMENT NOTIFICATION,- the first message is a UE CONTEXT SETUP REQUEST,- the first message is a UE CONTEXT MODIFICATION REQUEST,- the first message is a CU-DU Cell Switch Notification, and- the first message is a MEASUREMENT TRANSFER message.

10. The method according to any of claims 8-9, further comprising one or more one of:- receiving (302) from a third network node (113) or a fourth network node (114) operating in the communications network (100), a fourth indication indicating whether or not the LTM is possible,- determining (303), based on at least one of the received first message and the received fourth indication, whether or not to initiate the LTM,- initiating (304), responsive to the received first message, the one or more LTM procedures, and- sending (305), responsive to the received first message, a second message to the first network node (111), the second message indicating one of: i. whether or not the one or more LTM procedures have been initiated, ii. that the LTM is not allowed, and iii. whether or not L3 measurements are allowed to be used for execution of the LTM.

11. A method performed by a third network node (113), the method being for handling mobility, the third network node (113) operating in a communications network (100), and the method comprising:- receiving (401) a second indication from a first network node (111) operating in the communications network (100), the second indication requesting whether or not one or more L1 / L2-Triggered Mobility, LTM, procedures, are possible, and- sending (402), responsive to the received second indication, a third indication to the first network node (111), the third indication indicating whether or not the one or more LTM procedures are possible.

12. The method according to claim 11 , further comprising one or more of:- sending (403) to a second network node (112) operating in the communications network (100), a fourth indication indicating whether or not the one or more LTM procedures are possible, and- sending (404), based on the received second indication, a fifth indication to the device (130), the fifth indication triggering the one or more LTM procedures.

13. The method according to any of claims 11-12, wherein one or more of:- the first network node (111) serves the device (130),- the third network node (113) is a candidate to serve the device (130),- the first network node (111) is a Central Unit, CU,- the third network node (113) is another CU, and- the one or more LTM procedures comprise one or more of: i. an LTM cell switch procedure from a first cell (121) to a second cell (122), ii. an early synchronization procedure, iii. a candidate Transmission Configuration Indication, TCI, procedure, iv. an early uplink synchronization procedure, and v. a Timing Advance, TA, acquisition procedure.

14. A method performed by a device (130), the method being for handling mobility, the device (130) operating in a communications network (100), and the method comprising:- sending (501) a previous message to a first network node (111) operating in the communications network (100), the previous message indicating one or more L3 measurements, and- receiving (502) another indication, from a second network node (112) managed by the first network node (111), the another indication instructing the device (130)to perform one or more L1 / L2-Triggered Mobility, LTM, procedures, wherein the receiving (502) of the another indication is based on the sent previous message.

15. The method according to claim 14, further comprising:- receiving (503), based on the sent previous message, a fifth indication from a third network node (113) operating in the communications network (100), the fifth indication triggering the one or more LTM procedures.

16. The method according to any of claims 14-15, wherein one or more of:- the first network node (111) serves the device (130),- the second network node (112) serves the device (130),- the first network node (111) is a Central Unit,- the second network node (112) is a Distributed Unit, and- the one or more LTM procedures comprise one or more of: i. an LTM cell switch procedure from a first cell (121) to a second cell (122), ii. an early synchronization procedure, iii. a candidate Transmission Configuration Indication, TCI, procedure, iv. an early uplink synchronization procedure, and v. a Timing Advance, TA, acquisition procedure.

17. A first network node (111), for handling mobility, the first network node (111) being configured to operate in a communications network (100), and the first network node (111) being further configured to:- send a first message to a second network node (112) configured to operate in the communications network (100), the first message being configured to comprise a first indication configured to indicate one or more L1 / L2-Triggered Mobility, LTM, procedures for a device (130) configured to operate in the communications network (100), wherein the first message is configured to indicate one or more target cells or beams.

18. The first network node (111) according to claim 17, wherein one or more of:- the first network node (111) is configured to serve the device (130),- the second network node (112) is configured to serve the device (130),- the first network node (111) is configured to be a Central Unit,- the second network node (112) is configured to be a Distributed Unit,- the one or more LTM procedures are configured to comprise one or more of: i. an LTM cell switch procedure from a first cell (121) to a second cell (122),ii. an early synchronization procedure, iii. a candidate Transmission Configuration Indication, TCI, procedure, iv. an early uplink synchronization procedure, and v. a Timing Advance, TA, acquisition procedure,- the first message is configured to be an F1AP message,- the first message is configured to be Class 1 UE associated signalling or a Class2 UE associated signalling,- the first message is configured to indicate one or more Layer 3, L3, measurements performed by the device (130),- the first message is configured to request one or more Layer 1 , L1 , measurements performed by the device (130),- the first message is configured to indicate a change in a triggering LTM cell switch decision for one or more candidate cells,- the first indication is configured to be one of implicit and explicit, and- the first indication is configured to be per candidate cell or for all candidate cells.

19. The first network node (111) according to any of claims 17-18, further configured to one or more of:- receive a previous message from the device (130), the previous message being configured to indicate one or more L3 measurements, wherein the sending of the first message is configured to be based on the previous message configured to be received,- determine, based on the previous message configured to be received, whether or not to initiate the one or more LTM procedures, and wherein the sending of the first message is configured to be based on a result of the determination, and- receive, responsive to the first message configured to be sent, a second message from the second network node (112), the second message being configured to indicate one of: i. whether or not the one or more LTM procedures have been initiated, ii. that the LTM is not allowed, and iii. whether or not L3 measurements are allowed to be used for execution of the LTM.

20. The first network node (111) according to claims 18 and 19, being further configured to:- send a second indication to a third network node (113) configured to operate in the communications network (100), the second indication being configured to request whether or not the one or more LTM procedures are possible, andreceive, responsive to the second indication configured to be sent, a third indication from the third network node (113), the third indication being configured to indicate whether or not one or more LTM procedures are possible.

21. The first network node (111) according to any of claims 19-20, wherein the determining is configured to be based on one or more of:- failing to receive Layer 1 , L1, measurements,- a frequency of a carrier used,- one or more conditions,- at least one property of the L3 measurements fulfilling a first condition,- availability of specific L1 measurements, and- availability of the specific L1 measurements for one cell.

22. The first network node (111) according to any of claims 19-20, wherein one of:- the first message is configured to indicate whether or not the one or more LTM procedures are possible,- the first message is configured to indicate a request to initiate the one or more LTM procedures,- the first message is configured to indicate a preference to initiate the one or more LTM procedures,- the first message is configured to indicate a preference to initiate the one or more LTM procedures based on L3 measurements,- the first message is configured to indicate a preference to initiate the one or more LTM procedures based on L1 measurements,- the first message is configured to be a MEASUREMENT NOTIFICATION,- the first message is configured to be a UE CONTEXT SETUP REQUEST,- the first message is configured to be a UE CONTEXT MODIFICATIONREQUEST,- the first message is configured to be a CU-DU Cell Switch Notification, and- the first message is configured to be a MEASUREMENT TRANSFER message.

23. A second network node (112), for handling mobility, the second network node (112) being configured to operate in a communications network (100), and the second network node (112) being further configured to:- receive a first message from a first network node (111) configured to operate in the communications network (100), the first message being configured to comprise a first indication configured to indicate one or more L1 / L2-TriggeredMobility, LTM, procedures, for a device (130) configured to operate in the communications network (100), wherein the first message is configured to indicate one or more target cells or beams.

24. The second network node (112) according to claim 23, wherein one or more of:- the first network node (111) is configured to serve the device (130),- the second network node (112) is configured to serve the device (130),- the first network node (111) is configured to be a Central Unit,- the second network node (112) is configured to be a Distributed Unit,- the one or more LTM procedures are configured to comprise one or more of: i. an LTM cell switch procedure from a first cell (121) to a second cell (122), ii. an early synchronization procedure, iii. a candidate Transmission Configuration Indication, TCI, procedure, iv. an early uplink synchronization procedure, and v. a Timing Advance, TA, acquisition procedure,- the first message is configured to be an F1AP message,- the first message is configured to be Class 1 UE associated signalling or a Class2 UE associated signalling,- the first message is configured to indicate one or more Layer 3, L3, measurements configured to be performed by the device (130),- the first message is configured to request one or more Layer 1 , L1 , measurements performed by the device (130),- the first message is configured to indicate a change in a triggering LTM cell switch decision for one or more candidate cells,- the first indication is configured to be one of implicit and explicit, and- the first indication is configured to be per candidate cell or for all candidate cells.

25. The second network node (112) according to any of claims 23-24, wherein one of:- the first message is configured to indicate whether or not the one or more LTM procedures are possible,- the first message is configured to indicate a request to initiate the one or more LTM procedures,- the first message is configured to indicate a preference to initiate the one or more LTM procedures,- the first message is configured to indicate a preference to initiate the one or more LTM procedures based on L3 measurements,- the first message is configured to indicate a preference to initiate the one or more LTM procedures based on L1 measurements,- the first message is configured to be a MEASUREMENT NOTIFICATION,- the first message is configured to be a UE CONTEXT SETUP REQUEST,- the first message is configured to be a UE CONTEXT MODIFICATIONREQUEST,- the first message is configured to be a CU-DU Cell Switch Notification, and- the first message is configured to be a MEASUREMENT TRANSFER message.

26. The second network node (112) according to any of claims 24-25, further configured to one or more one of:- receive, from a third network node (113) or a fourth network node (114) configured to operate in the communications network (100), a fourth indication configured to indicate whether or not the LTM is possible,- determine, based on at least one of the first message and the received fourth indication configured to be received, whether or not to initiate the LTM,- initiate, responsive to the first message configured to be received, the one or more LTM procedures, and- send, responsive to the first message configured to be received, a second message to the first network node (111), the second message configured to indicate one of: i. whether or not the one or more LTM procedures have been initiated, ii. that the LTM is not allowed, and iii. whether or not L3 measurements are allowed to be used for execution of the LTM.

27. A third network node (113), for handling mobility, the third network node (113) being configured to operate in a communications network (100), and the third network node (113) being further configured to:- receive a second indication from a first network node (111) configured to operate in the communications network (100), the second indication being configured to request whether or not one or more L1 / L2-Triggered Mobility, LTM, procedures, are possible, and- send, responsive to the second indication configured to be received, a third indication to the first network node (111), the third indication being configured to indicate whether or not the one or more LTM procedures are possible.

28. The third network node (113) according to claim 27, being further configured to one or more of:- send, to a second network node (112) configured to operate in the communications network (100), a fourth indication configured to indicate whether or not the one or more LTM procedures are possible, and- send, based on the second indication configured to be received, a fifth indication to the device (130), the fifth indication being configured to trigger the one or more LTM procedures.

29. The third network node (113) according to any of claims 27-28, wherein one or more of:- the first network node (111) is configured to serve the device (130),- the third network node (113) is configured to be a candidate to serve the device (130),- the first network node (111) is configured to be a Central Unit, CU,- the third network node (113) is configured to be another CU, and- the one or more LTM procedures are configured to comprise one or more of: i. an LTM cell switch procedure from a first cell (121) to a second cell (122), ii. an early synchronization procedure, iii. a candidate Transmission Configuration Indication, TCI, procedure, iv. an early uplink synchronization procedure, and v. a Timing Advance, TA, acquisition procedure.

30. A device (130) performed by a device (130), for handling mobility, the device (130) being configured to operate in a communications network (100), and the device (130) being further configured to:- send a previous message to a first network node (111) configured to operate in the communications network (100), the previous message being configured to indicate one or more L3 measurements, and- receive another indication, from a second network node (112) configured to be managed by the first network node (111), the another indication being configured to instruct the device (130) to perform one or more L1 / L2-Triggered Mobility, LTM, procedures, wherein the receiving of the another indication is configured to be based on the previous message configured to be sent.

31. The device (130) according to claim 30, being further configured to:- receive, based on the previous message configured to be sent, a fifth indication from a third network node (113) configured to operate in the communicationsnetwork (100), the fifth indication being configured to trigger the one or more LTM procedures.

32. The device (130) according to any of claims 30-31 , wherein one or more of: - the first network node (111) is configured to serve the device (130),- the second network node (112) is configured to serve the device (130),- the first network node (111) is configured to be a Central Unit,- the second network node (112) is configured to be a Distributed Unit, and- the one or more LTM procedures are configured to comprise one or more of: i. an LTM cell switch procedure from a first cell (121) to a second cell (122), ii. an early synchronization procedure, iii. a candidate Transmission Configuration Indication, TCI, procedure, iv. an early uplink synchronization procedure, and v. a Timing Advance, TA, acquisition procedure.

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