Indicating status of timer for uplink transmission extension

Abstract

Various embodiments of the present disclosure relate to indicating a state of a timer for uplink transmission extension. Disclosed is a method comprising: determining a state of a timer for uplink transmission extension of a user equipment, a global navigation satellite system effective duration of the user equipment having expired; and transmitting information indicating a state of a timer of the user equipment to an access node of the target cell controlling the handover of the user equipment.

Description

Technical Field

[0001] The following example embodiments relate to wireless communication. Background Technology

[0002] For communication in non-terrestrial networks, in principle, a UE is not allowed to transmit in the uplink when its location expires, because the expected pre-compensation would be incorrect. However, if the network determines that the UE is accurately pre-compensating, the network can configure a T390 timer for the UE to extend uplink transmission. This allows the UE to continue uplink transmission after the location expires. Summary of the Invention

[0003] The scope of protection sought by the various exemplary embodiments is set forth in the claims. Exemplary embodiments and features (if any) described herein that do not fall within the scope of the claims should be interpreted as examples useful for understanding the various embodiments.

[0004] According to a first aspect, an apparatus is provided, comprising: components for determining the state of a timer for an uplink transmission extension of a user equipment, the global navigation satellite system effective duration of which has expired; and components for transmitting information indicating the state of the timer of the user equipment to an access node of a target cell controlling a handover of the user equipment.

[0005] According to the second aspect, an apparatus according to the first aspect is provided, wherein the state of the timer includes at least the remaining time of the timer.

[0006] According to a third aspect, an apparatus according to the first or second aspect is provided, wherein the state of the timer includes at least the start time of the timer and the configured value of the timer.

[0007] According to the fourth aspect, an apparatus according to any one of the first to third aspects is provided, wherein determining the state of a timer includes at least determining that the timer is running, wherein the information includes at least an indication that the timer is running.

[0008] According to the fifth aspect, an apparatus according to the fourth aspect is provided, wherein an access node controlling the target cell is instructed to reset a timer to a configured value when a handover is completed.

[0009] According to the sixth aspect, an apparatus according to the fourth or fifth aspect is provided, wherein instructing an access node controlling a target cell to provide uplink resources to a user equipment is used to indicate the value of a timer to the access node controlling the target cell.

[0010] According to the seventh aspect, an apparatus according to any one of the first to sixth aspects is provided, wherein the apparatus is a user equipment, and information indicating the state of a timer is transmitted during or after a switching process.

[0011] According to the eighth aspect, an apparatus according to the seventh aspect is provided, further comprising a component for resetting a timer to a configured value when a switch is initiated or completed.

[0012] According to the ninth aspect, an apparatus according to the seventh or eighth aspect is provided, wherein the switching is a conditional switching.

[0013] According to the tenth aspect, an apparatus according to any one of the first to sixth aspects is provided, wherein the apparatus is an access node of a source cell for controlling the handover of user equipment.

[0014] According to the eleventh aspect, an apparatus according to the tenth aspect is provided, wherein information indicating the state of the timer is transmitted in a switching request message for requesting a switching.

[0015] According to the twelfth aspect, an apparatus according to the tenth or eleventh aspect is provided, further comprising a component for transmitting to a user equipment an indication of when information is transmitted to an access node controlling a target cell, wherein the indication transmitted to the user equipment causes the user equipment to determine whether to indicate a timer value to the access node controlling the target cell.

[0016] According to a thirteenth aspect, an access node for a target cell controlling the handover of a user equipment is provided. The access node includes: components for receiving information from a device indicating the state of a timer for an extended uplink transmission period for the user equipment, where the effective duration of the user equipment's Global Navigation Satellite System (GNSS) transmission has expired; and components for performing actions based on the information, wherein the actions include one of: enabling automatic GNSS measurements at the user equipment when the timer expires; releasing the user equipment to a Radio Resource Control (RRC) idle mode when the timer expires; resetting the timer to a configured value when the handover is completed; providing uplink resources to the user equipment to indicate the timer value to the access node controlling the target cell; or triggering a GNSS measurement gap for the user equipment.

[0017] In the fourteenth aspect, an access node according to the thirteenth aspect is provided, wherein the state of the timer includes at least the remaining time of the timer.

[0018] In the fifteenth aspect, an access node according to the thirteenth or fourteenth aspect is provided, wherein the state of the timer includes at least the start time of the timer and the configured value of the timer.

[0019] According to the sixteenth aspect, an access node according to any one of the thirteenth to fifteenth aspects is provided, wherein the information includes at least an indication that a timer is running.

[0020] According to the seventeenth aspect, an access node according to any one of the thirteenth to sixteenth aspects is provided, wherein the component for receiving information is configured to receive information from the user equipment during or after handover.

[0021] According to the eighteenth aspect, an access node according to any one of the thirteenth to sixteenth aspects is provided, wherein the component for receiving information is configured to receive information in a handover request message from the access node of the source cell controlling the handover.

[0022] According to the nineteenth aspect, a method is provided, comprising: determining the state of a timer for uplink transmission extension of a user equipment, wherein the effective duration of the user equipment's Global Navigation Satellite System (GNSS) has expired; and transmitting information indicating the state of the user equipment's timer to an access node of a target cell controlling the handover of the user equipment.

[0023] According to a twentieth aspect, a method is provided executed by an access node of a target cell controlling the handover of a user equipment (UE), the method comprising: receiving from a device information indicating the state of a timer for an uplink transmission extension of the UE, wherein the effective duration of the UE's Global Navigation Satellite System (GNSS) has expired; and performing an action based on the information, wherein the action comprises one of: enabling automatic GNSS measurements at the UE when the timer expires; releasing the UE to a radio resource control idle mode when the timer expires; resetting the timer to a configured value when the handover is completed; providing uplink resources to the UE to indicate the value of the timer to the access node controlling the target cell; or triggering a GNSS measurement gap for the UE.

[0024] According to the twenty-first aspect, a computer program is provided, including instructions that, when executed by a device, cause the device to perform at least the following operations: determining the state of a timer for uplink transmission extension of a user equipment, wherein the effective duration of the user equipment's Global Navigation Satellite System has expired; and transmitting information indicating the state of the user equipment's timer to an access node of a target cell controlling the handover of the user equipment.

[0025] According to the twenty-second aspect, a computer program is provided, including instructions that, when executed by an access node of a target cell controlling a handover of a user equipment, cause the access node to perform at least the following operations: receive from a device information indicating the state of a timer for an extended uplink transmission period for the user equipment, wherein the effective duration of the user equipment's Global Navigation Satellite System (GNSS) has expired; and perform an action based on the information, wherein the action includes one of: enabling automatic GNSS measurements at the user equipment when the timer expires; releasing the user equipment to a Radio Resource Control (RRC) idle mode when the timer expires; resetting the timer to a configured value when the handover is completed; providing uplink resources to the user equipment to indicate the timer value to the access node controlling the target cell; or triggering a GNSS measurement gap for the user equipment.

[0026] According to the twenty-third aspect, a non-transitory computer-readable medium is provided, including program instructions that, when executed by a device, cause the device to perform at least the following operations: determining the state of a timer for uplink transmission extension of a user equipment, wherein the effective duration of the user equipment's Global Navigation Satellite System has expired; and transmitting information indicating the state of the user equipment's timer to an access node of a target cell controlling the handover of the user equipment.

[0027] According to the twenty-fourth aspect, a non-transitory computer-readable medium is provided, including program instructions that, when executed by an access node of a target cell controlling a handover of a user equipment, cause the access node to perform at least the following operations: receive from a device information indicating the state of a timer for an uplink transmission extension of the user equipment, wherein the effective duration of the user equipment's Global Navigation Satellite System (GNSS) has expired; and perform an action based on the information, wherein the action includes one of: enabling automatic GNSS measurements at the user equipment when the timer expires; releasing the user equipment to a Radio Resource Control (RRC) idle mode when the timer expires; resetting the timer to a configured value when the handover is completed; providing uplink resources to the user equipment to indicate the value of the timer to the access node controlling the target cell; or triggering a GNSS measurement gap for the user equipment.

[0028] According to the twenty-fifth aspect, a computer-readable medium is provided, including program instructions that, when executed by an apparatus, cause the apparatus to perform at least the following operations: determining the state of a timer for an uplink transmission extension of a user equipment, wherein the effective duration of the user equipment's Global Navigation Satellite System has expired; and transmitting information indicating the state of the user equipment's timer to an access node of a target cell controlling the handover of the user equipment.

[0029] According to the twenty-sixth aspect, a computer-readable medium is provided, including program instructions that, when executed by an access node of a target cell controlling a handover of a user equipment, cause the access node to perform at least the following operations: receive from a device information indicating the state of a timer for an uplink transmission extension of the user equipment, wherein the effective duration of the user equipment's Global Navigation Satellite System (GNSS) has expired; and perform an action based on the information, wherein the action includes one of: enabling automatic GNSS measurements at the user equipment when the timer expires; releasing the user equipment to a Radio Resource Control (RRC) idle mode when the timer expires; resetting the timer to a configured value when the handover is completed; providing uplink resources to the user equipment to indicate the value of the timer to the access node controlling the target cell; or triggering a GNSS measurement gap for the user equipment.

[0030] According to the twenty-seventh aspect, an apparatus is provided, comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: determine the state of a timer for an uplink transmission extension of a user equipment, wherein the effective duration of the user equipment's Global Navigation Satellite System (GNSS) has expired; and transmit information indicating the state of the user equipment's timer to an access node of a target cell controlling the handover of the user equipment.

[0031] According to the twenty-eighth aspect, an access node for a target cell controlling the handover of a user equipment is provided. The access node includes at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the access node to at least: receive from a device information indicating the state of a timer for an extended uplink transmission for the user equipment, whereby the effective duration of the user equipment's Global Navigation Satellite System (GNSS) signal has expired; and perform an action based on the information, wherein the action includes one of: enabling automatic GNSS measurements at the user equipment when the timer expires; releasing the user equipment to a Radio Resource Control (RRC) idle mode when the timer expires; resetting the timer to a configured value when the handover is completed; providing uplink resources to the user equipment to indicate the timer value to the access node controlling the target cell; or triggering a GNSS measurement gap for the user equipment. Attached Figure Description

[0032] In the following description, various exemplary embodiments will be described in more detail with reference to the accompanying drawings, wherein

[0033] Figure 1A An example of a wireless communication network is shown;

[0034] Figure 1B An example of the system is shown;

[0035] Figure 2The signal flow graph is shown;

[0036] Figure 3 The signal flow graph is shown;

[0037] Figure 4 A flowchart is shown;

[0038] Figure 5 A flowchart is shown;

[0039] Figure 6 An example of the device is shown; and

[0040] Figure 7 An example of the device is shown. Detailed Implementation

[0041] The following embodiments are exemplary. Although the specification may refer to "a," "an," or "some" embodiments in various places in the text, this does not necessarily mean that the same embodiment is referred to every time, or that a particular feature applies only to a single embodiment. Individual features of different embodiments may also be combined to provide other embodiments within the scope of the claims. Furthermore, the words "comprising" and "including" should be understood not to limit the described embodiments to consisting only of those features already mentioned, and such embodiments may also include features not yet specifically mentioned. In the specification and / or claims, reference numerals are used to illustrate embodiments with reference to the accompanying drawings, and not to limit the embodiments to these examples.

[0042] Some example embodiments described herein can be implemented in wireless communication networks that include radio access technologies (RATs) based on one or more of the following: Global System for Mobile Communications (GSM) or any other second-generation (2G) radio access technology, Universal Mobile Telecommunications System (UMTS, 3G) based on Basic Wideband Code Division Multiple Access (W-CDMA), High-Speed ​​Packet Access (HSPA), Long Term Evolution (LTE), Advanced LTE, Narrowband Internet of Things (NB-IoT), Enhanced Machine-Type Communications (eMTC), fourth-generation (4G), fifth-generation (5G), 5G New Radio (NR), Advanced 5G (i.e., 3GPP NR Rel-18 and later), or sixth-generation (6G). Some examples of radio access networks include Universal Mobile Telecommunications System (UMTS) Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRA), or Next Generation Radio Access Network (NG-RAN). The wireless communication network may also include a core network, and some example embodiments may also be applied to the network functions of the core network.

[0043] It should be noted that the embodiments are not limited to the wireless communication networks given as examples, but those skilled in the art can also apply this technical solution to other wireless communication networks or systems that provide the necessary attributes. For example, some example embodiments can also be applied to communication systems based on the IEEE 802.11 standard or communication systems based on the IEEE 802.15 standard. IEEE is an abbreviation for the Institute of Electrical and Electronics Engineers.

[0044] Figure 1A An example of a simplified wireless communication network is depicted, showing some physical and logical entities. Figure 1A The connection shown can be a physical connection or a logical connection. It will be apparent to those skilled in the art that the wireless communication network may also include, in addition to… Figure 1A Other physical and logical entities besides those shown.

[0045] However, the exemplary embodiments described herein are not limited to the wireless communication networks given as examples, but those skilled in the art can apply the exemplary embodiments described herein to other wireless communication networks that provide the necessary properties.

[0046] Figure 1A The example wireless communication network shown includes a radio access network (RAN) and a core network 110.

[0047] Figure 1A User equipment (UE) 100 and UE 102 are shown, which are configured to wirelessly connect to access node (AN) 104 of radio access network on one or more communication channels in radio cell.

[0048] Access node 104 may include a computing device configured to control the radio resources of access node 104 and to be wirelessly connected to one or more UEs 100 and UE 102. Access node 104 may also be referred to as a base station, base transceiver station (BTS), access point, cell site, network node, radio access network node, or RAN node.

[0049] Access node 104 may be, for example, an evolved Node B (eNB or eNodeB) providing a radio cell, a next-generation evolved Node B (ng-eNB), or a next-generation Node B (gNB or gNodeB). Access node 104 may include or be coupled to a transceiver. From the transceiver of access node 104, a connection may be provided to an antenna element that establishes a bidirectional radio link to one or more UEs 100 and UE 102. The antenna element may include an antenna or antenna element, or multiple antennas or antenna elements.

[0050] The radio connection (e.g., a radio link) from UE 100, UE 102 to access node 104 may be referred to as an uplink (UL) or reverse link, and the radio connection (e.g., a radio link) from access node 104 to UE 100, UE 102 may be referred to as a downlink (DL) or forward link. UE 100 may also communicate directly with another UE 102 via a radio connection commonly referred to as a side link (SL), and vice versa. It should be understood that access node 104 or its functionality can be implemented using any node, host, server, access point, or other entity suitable for providing such functionality.

[0051] A radio access network may include more than one access node 104, in which case the access nodes may also be configured to communicate with each other via wired or wireless links. These links between access nodes may be used to send and receive control plane signaling, and also to route data from one access node to another.

[0052] Access node 104 can also connect to core network (CN) 110. Core network 110 may include an evolved packet core (EPC) network and / or a fifth-generation core network (5GC). EPC may include network entities such as a serving gateway (S-GW for routing and forwarding data packets), a packet data network gateway (P-GW) for providing connectivity to external packet data networks for the UE, and / or a mobility management entity (MME). 5GC may include one or more network functions such as at least one of the following: user plane function (UPF), access and mobility management function (AMF), location management function (LMF), and / or session management function (SMF).

[0053] The core network 110 may also be able to communicate with or utilize services provided by one or more external networks 113, such as the public switched telephone network or the Internet. For example, in a 5G wireless communication network, the UPF of the core network 110 may be configured to communicate with an external data network via the N6 interface. In an LTE wireless communication network, the P-GW of the core network 110 may be configured to communicate with an external data network.

[0054] It should also be understood that, compared to LTE or 5G, the functional distribution between core network operations and access node operations may differ in future wireless communication networks, or may not even exist.

[0055] The UE 100 and UE 102 shown are a type of apparatus to which resources on the air interface can be allocated and assigned. UE 100 and UE 102 may also be referred to as wireless communication equipment, subscriber unit, mobile station, remote terminal, access terminal, user terminal, terminal equipment, or user equipment, to name just a few. UE 100 and UE 102 may be computing devices operating with or without a subscriber identification module (SIM), including but not limited to the following types of computing devices: mobile phones, smartphones, personal digital assistants (PDAs), handheld devices, computing devices including wireless modems (e.g., alarm or measuring devices), laptop computers, desktop computers, tablet computers, game consoles, laptops, multimedia devices, redcap devices, wearable devices with radio components (e.g., watches, headphones, or glasses), sensors including wireless modems, or computing devices including wireless modems integrated in vehicles.

[0056] It should be understood that UE 100 and UE 102 can also be almost dedicated uplink-only devices, examples of which could be cameras or camcorders that load image or video clips onto the network. UE 100 and UE 102 can also be devices capable of operating in Internet of Things (IoT) networks, which are scenarios where the ability to deliver data over a network to objects can be provided without requiring human-to-human or human-to-computer interaction is required.

[0057] Wireless communication networks can also support the use of cloud services. For example, at least a portion of the core network operation can be used as a cloud service (this is in...). Figure 1A The computation is performed in the cloud (described by “cloud” 114). UE 100 and UE 102 can also utilize cloud 114. In some applications, computations for a given UE can be performed in cloud 114 or in another UE.

[0058] Wireless communication networks may also include a central control entity, such as a Network Management System (NMS). An NMS is a centralized suite of software and hardware used to monitor, control, and manage network infrastructure. The NMS is responsible for a wide range of tasks, such as fault management, configuration management, security management, performance management, and billing management. The NMS enables network operators to efficiently manage and optimize network resources, ensuring the network delivers high performance, reliability, and security.

[0059] 5G enables the use of multiple-input multiple-output (MIMO) antennas in access node 104, and / or UE 100, UE 102, far more base stations or access nodes than LTE networks (the so-called small cell concept), including macro sites cooperating with smaller stations, and employing a variety of radio technologies depending on service requirements, use cases, and / or available spectrum. 5G wireless communication networks can support a wide range of use cases and related applications, including video streaming, augmented reality, different data sharing methods, and various forms of machine-type applications such as (massive) machine-type communication (mMTC), including vehicle safety, various sensors, and real-time control.

[0060] In 5G wireless communication networks, access nodes and / or UEs can have multiple radio interfaces, such as sub-6 GHz, centimeter wave (cmWave), and millimeter wave (mmWave), and can also be integrated with traditional radio access technologies (such as LTE). Integration with LTE can be implemented, for example, in a system where macro coverage can be provided by LTE, and 5G radio interface access can originate from small cells by aggregation to LTE. In other words, 5G wireless communication networks can support both RAT interoperability (such as interoperability between LTE and 5G) and RI interoperability (interoperability between radio interfaces, such as between sub-6 GHz, cmWave, and mmWave).

[0061] 5G wireless communication networks can also apply network slicing, in which multiple independent and dedicated virtual sub-networks (network instances) can be created within the same physical infrastructure to run services with different requirements for latency, reliability, throughput and mobility.

[0062] In one embodiment, access node 104 may include: a radio unit (RU) 103 including radio transceivers (TRXs), i.e., transmitters (Tx) and receivers (Rx); one or more distributed units (DUs) 105, which can be used for so-called Layer 1 (L1) processing and real-time Layer 2 (L2) processing; and a central unit (CU) 108 (also called a centralized unit), which can be used for non-real-time Layer 2 and Layer 3 (L3) processing. CU 108 may be connected to one or more DUs 105, for example, via an F1 interface. Such an embodiment of access node 104 allows for the centralization of CUs relative to cell sites and DUs, while DUs can be more distributed and may even remain at the cell site. CUs and DUs together may also be referred to as baseband or baseband unit (BBU). CUs and DUs may also be included in a radio access point (RAP).

[0063] CU 108 may be a logical node hosting the Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and / or Packet Data Convergence Protocol (PDCP) for the NR protocol stack used by access node 104. CU 108 may include a control plane (CU-CP), which may be a logical node hosting the RRC and control plane portions of the PDCP protocol for the NR protocol stack used by access node 104. CU 108 may also include a user plane (CU-UP), which may be a logical node hosting the user plane portions of the PDCP and SDAP protocols for the CU used by access node 104.

[0064] DU 105 can be a logical node hosting the Radio Link Control (RLC), Media Access Control (MAC), and / or Physical (PHY) layers of the NR protocol stack used by Access Node 104. The operation of DU 105 can be controlled at least partially by CU 108. It should also be understood that the functional distribution between DU 105 and CU 108 can vary depending on the implementation.

[0065] Cloud computing systems can also be used to provide CU 108 and / or DU 105. CUs provided by cloud computing systems can be referred to as virtualized CUs (vCUs). In addition to vCUs, virtualized DUs (vDUs) provided by cloud computing systems can also exist. Furthermore, combinations can exist where DUs can be implemented on so-called bare-metal technologies, such as application-specific integrated circuits (ASICs) or customer-specific standard product (CSSP) system-on-chips (SoCs).

[0066] Edge cloud can be brought into the radio access network by leveraging Network Functions Virtualization (NFV) and Software-Defined Networking (SDN). Using edge cloud can mean that access node operations will be performed, at least partially, on a computing system operatively coupled to the Remote Radio Head (RRH) or Radio Unit (RU) 103 at access node 104. Access node operations can also be performed on a distributed computing system or cloud computing system located at access node 104. The application of a cloud RAN architecture enables the execution of real-time RAN functions at the radio access network (e.g., in DU 105) and the execution of non-real-time functions in a centralized manner (e.g., in CU 108).

[0067] 5G (or New Radio (NR)) wireless communication networks can support multiple tiers, where multi-access edge computing (MEC) servers can be placed between the core network 110 and access nodes 104. It should be understood that MEC can also be applied to LTE wireless communication networks.

[0068] It is obvious to those skilled in the art that Figure 1AThe access node 104 depicted is merely an example of a portion of a radio access network, and in practice, a radio access network may include multiple access nodes 104, UE 100 and UE 102 may access multiple radio cells, and the radio access network may also include other devices, such as physical layer relay access nodes or other entities. At least one of the access nodes may be a home eNodeB or a home gNodeB. A home gNodeB or home eNodeB is a type of access node that can be used to provide indoor coverage in a home, office, or other indoor environment.

[0069] In addition, multiple different types of radio cells and multiple radio cells can be provided within the geographical area of ​​the radio access network. Radio cells can be macrocells (or umbrella cells), which can be areas with diameters of up to tens of kilometers, or smaller cells such as microcells, femtocells, or picocells. Figure 1A Access node 104 can provide any type of these cells. A cellular radio network can be implemented as a multi-layered access network comprising several types of radio cells. In a multi-layered access network, one access node can provide one or more radio cells, and therefore multiple access nodes may be required to provide such a multi-layered access network.

[0070] To meet the need for improved electrical performance in radio access networks, the concept of "plug-and-play" access nodes can be introduced. Besides home eNodeBs or home gNodeBs, radio access networks capable of using "plug-and-play" access nodes can also include home node B gateways (HNB-GW). Figure 1A (Not shown in the image). An HNB-GW, which can be installed within an operator's radio access network, can aggregate traffic from a large number of home eNodeBs or home gNodeBs back to the operator's core network 110.

[0071] 6G wireless communication networks are expected to employ flexible decentralized and / or distributed computing systems and architectures, along with ubiquitous computing, where local spectrum licensing, spectrum sharing, infrastructure sharing, and intelligent automated management are determined by mobile edge computing, artificial intelligence, short packet communication, and blockchain technologies. Key features of 6G may include intelligent connectivity management and control capabilities, programmability, integrated sensing and communication, reduced energy consumption, trusted infrastructure, scalability, and affordability. In addition, 6G addresses new use cases by integrating location and sensing capabilities into the system definition to unify the user experience across the physical and digital worlds.

[0072] Wireless communication networks (e.g., 5G or 6G networks) may also include non-terrestrial networks (NTNs), such as satellite communication networks, to enhance or supplement the coverage of the radio access network. For example, satellite communications can support data transmission between the 5G radio access network and the core network 110, thereby enabling broader network coverage. Possible use cases may include providing service continuity for machine-to-machine (M2M) or Internet of Things (IoT) devices or for passengers on transportation vehicles, or ensuring service availability for critical communications and future rail, maritime, or air communications. Satellite communications may utilize geostationary Earth orbit (GEO) or low Earth orbit (LEO) satellite systems, such as mega-constellations (i.e., systems in which hundreds of (nanometer) satellites are deployed). Alternatively, satellites may be aerial devices, such as unmanned aerial vehicles (UAVs) or high-altitude platform systems (HAPS). A given satellite 106 may provide communication services on Earth via one or more satellite beams. One or more satellite beams create one or more cells over a given service area that can be defined by the field of view of satellite 106.

[0073] In the transparent architecture of the non-terrestrial network, the access node (NTN gateway) 104 of the non-terrestrial network is located on the ground (i.e., the base station 104 is on Earth). In this case, the satellite 106 can simply forward the signals it receives from the NTN gateway 104 to one or more UEs 100 and UE 102, and vice versa (i.e., the satellite 106 acts as a repeater between one or more UEs 100 and UE 102 and the NTN gateway 104). In the transparent architecture, there can be a feeder link between the satellite 106 and the terrestrial NTN gateway 104, as well as a service link between the satellite 106 and one or more UEs 100 and UE 102 within the target service area. The transparent architecture can also be referred to as a transparent payload architecture.

[0074] Alternatively, in a regenerative architecture for a non-terrestrial network, the access nodes for the non-terrestrial network (i.e., some or all base station functions) reside on the satellite 106 itself. In this architecture, a terrestrial NTN gateway 104 or feeder link is not required. This means that the satellite 106 does not merely forward signals; it can process the signals it receives, performing functions such as decoding, demodulation, and remodulation, and then transmit the processed signals to one or more UEs 100 and UE 102 via a service link. This regenerative architecture can also be referred to as having a regenerative payload.

[0075] One or more UE 100, UE 102 may have Global Navigation Satellite System (GNSS) support. GNSS is a network of satellites that transmits positioning and timing data to GNSS receivers (e.g., UE 100, UE 102) located on or near the Earth's surface. These receivers (e.g., UE 100, UE 102) then use the data to determine their location (i.e., positioning). Global Positioning System (GPS) is an example of GNSS. It should be noted that NTN satellite 106 may be separate from the GNSS satellites.

[0076] For example, GNSS satellites can be distributed in a medium Earth orbit (MEO) approximately 20,000 kilometers above the Earth's surface. GNSS satellites can be arranged such that at least four satellites are visible from any point on the Earth's surface at any given time. This visibility allows UE 100 and UE 102 to calculate the precise time delay of signals received from a given GNSS satellite, and therefore calculate the distances from UE 100 and UE 102 to the GNSS satellites. With the distances to at least four satellites known, UE 100 and UE 102 can determine their GNSS positions in three dimensions.

[0077] For a serving cell in a non-terrestrial communication network, the network (e.g., NTN gateway 104 or satellite 106) can broadcast ephemeris information (i.e., the trajectory of satellite 106) and common timing advance (TA) parameters. The ephemeris information indicates the position of satellite 106 relative to time. Before connecting to the NTN cell, UE 100 and UE 102 should have valid GNSS positions, ephemeris information, and common TA. To achieve synchronization, before and during connection to the NTN cell, UE 100 and UE 102 should pre-compensate for timing advance by taking into account the common TA, GNSS positions, and NTN payload positions of UE 100 and UE 102 using the ephemeris information. Timing advance is the amount of time that UE 100 and UE 102 use to adjust or advance the timing of uplink frames to align with downlink frames in the time domain. Pre-compensation refers to the adjustments made by UE 100 and UE 102 to their signal transmissions to achieve synchronization with the NTN cell (e.g., to mitigate the Doppler shift experienced on the serving link).

[0078] For example, UE 100 and UE 102 can calculate the frequency Doppler shift of the service link between UE 100 / UE 102 and satellite 106 by considering the UE location and the ephemeris of satellite 106, and pre-compensate for it in uplink transmissions. In another example, UE 100 and UE 102 can calculate the time shift of the service link between UE 100 / UE 102 and satellite 106, as well as the feeder link between satellite 106 and NTN gateway 104. If UE 100 / UE 102 does not have valid ephemeris and common TA, it may not transmit until they are reacquired. If the GNSS location becomes outdated, UE 100 / UE 102 should not transmit unless an active uplink transmission extension is configured.

[0079] In connected (RRC connected) mode, UE 100 and UE 102 should continuously update timing advance and frequency precompensation. UE 100 and UE 102 can be triggered to perform or configured to automatically perform GNSS acquisition. In connected mode, UE 100 and UE 102 should acquire broadcast parameters when ephemeris and common timing advance expire. In the event of GNSS acquisition failure, if the GNSS location expires and uplink transmission extension is inactive, UE 100 and UE 102 can move to idle (RRC idle) mode. In the case of expired GNSS location, UE 100 and UE 102 can move to idle mode unless GNSS acquisition is triggered or uplink transmission extension is active. Upon completion of GNSS acquisition, UE 100 and UE 102 can trigger a report of the remaining valid GNSS duration.

[0080] The GNSS effective duration defines the period during which the GNSS location of UE 100 and UE 102 is expected to be valid. In other words, when the GNSS effective duration expires, it means that the GNSS location of UE 100 and UE 102 has expired. For example, a stationary UE or a pedestrian UE can expect a long GNSS effective duration because of its small location change, while a fast-moving UE (e.g., in a car, train, or airplane) will have a shorter GNSS effective duration due to its rapid movement.

[0081] When the location of UE 100 and UE 102 expires (i.e., the effective GNSS duration has expired), UE 100 and UE 102 are generally not allowed to transmit in the uplink because the expected pre-compensation would be incorrect. However, if the network determines that UE 100 and UE 102 are accurately pre-compensating, the network can configure a T390 timer for uplink transmission extension for the UE. In other words, the T390 timer is a feature that the network can configure if it determines that the UE's uplink transmission is well aligned in time and frequency. This allows UE 100 and UE 102 to continue uplink transmission after their GNSS location has expired. For example, this might be the case if UE 100 and UE 102 are stationary (not moving), meaning that the previously reported GNSS location is still valid and can therefore be used for pre-compensation (even though the effective GNSS duration has expired).

[0082] In this specification, the terms "T390 timer" and "timer for uplink transmission extension" are used interchangeably. In this document, T390 timer refers to timer T390 as defined in 3GPP specifications (e.g., TS36.331). The T390 timer may also be referred to as an uplink transmission extension timer, or simply as a timer. When an indication that a GNSS location has become expired while in an RRC connection is received, if UL transmission extension is configured and if the time alignment timer is configured to infinity, the UE may start timer T390, where the timer value is set to the UL transmission extension value, and the UE may later restart (reset) timer T390 (before its expiration) upon indication from a lower layer to extend UL transmission (extend the time allowed for the UE to transmit in the uplink).

[0083] Otherwise, if the time alignment timer is not configured to infinity, the UE can start timer T390, where the timer value is set to the remaining time of the time alignment timer, and the UE can later restart (reset) timer T390 (before its expiration) to extend UL transmission upon indication from a lower layer, where the timer value is set to the remaining time of the time alignment timer. The time alignment timer (TAT) is a UE-specific timer defined in the MAC layer to account for the effectiveness of timing advance, i.e., the UE is uplink time aligned. The UE starts the TAT based on certain conditions, so it will have a remaining value at some later point in time. The UE can check the remaining value internally.

[0084] In other words, when the effective duration of GNSS expires (if ul transmission extension is enabled and configured), the UE can start timer T390, and the cell can then trigger a further extension (i.e., a restart of T390) by using the Media Access Control (MAC) control element (CE).

[0085] The T390 timer can be stopped when leaving RRC connection mode or when receiving a network-triggered GNSS measurement.

[0086] If timer T390 expires and no indication of a network-triggered GNSS measurement has been received from a lower layer, the UE may perform automatic GNSS measurement (if configured). If not configured to perform automatic GNSS measurement, the UE may move to RRC idle mode upon T390 expiration. GNSS measurement means estimating the UE's position (location) based on signals received from GNSS satellites. In the current specification, the duration of timer T390 can range from 0.5 seconds to 10 seconds.

[0087] The UE can be configured to perform GNSS measurements during GNSS measurement gaps based on network triggering, or the UE can be configured to automatically start GNSS measurements when the valid GNSS duration expires or when the T390 timer expires. If an instruction to perform GNSS measurements is received from a lower layer, the UE can perform GNSS measurements using a GNSS measurement gap with a gap length indicated by the lower layer, and if running, timer T390 is stopped. If GNSS-Auto Enable is configured, the UE can perform GNSS measurements using an automatic GNSS measurement gap that begins when T390 expires, if ul-Transmission Extension Enable is configured. Otherwise, the UE can start GNSS measurements from the expiration of the valid GNSS duration, where the gap length is indicated by the lower layer or, if not indicated by the lower layer, equal to the duration of the latest report required for the UE to acquire GNSS position.

[0088] Figure 1B An example of the system is shown. Figure 1B The system can be understood as describing Figure 1A It is part of the wireless communication network, but has higher accuracy regarding handover scenarios.

[0089] Reference Figure 1BDuring handover, the connection of UE 100 is transferred from the current serving cell (source cell) 121 controlled by the source access node (e.g., satellite) 106 to the target cell 122 controlled by the target access node (e.g., another satellite) 106B, while maintaining ongoing voice calls or data sessions. In this document, source cell 121 and target cell 122 can be NTN cells. In another example, serving cell 121 and target cell 122 can be provided by the same satellite 106.

[0090] When certain predefined conditions are met, such as when the signal quality of the current serving cell (source cell) 121 drops below a specified threshold, or when the signal quality of the target cell (neighboring cell) 122 becomes better than the signal quality of the current serving cell 121 by a predefined offset, the handover process can be initiated by the network (e.g., source access node 106). The decision to perform the handover can be based on various factors, including radio measurements such as Reference Received Power (RSRP) and / or Reference Received Quality (RSRQ), network load, UE mobility, location-based thresholds, time-based windows, and network configuration parameters.

[0091] During normal handover, the network (e.g., source access node 106) can transmit a handover command to the UE 100, which may include information about the target cell 122 and any required configuration parameters. The UE 100 can then establish a connection with the target access node 106B that controls the target cell 122, synchronize the timing and frequency of the target access node 106B, and exchange control information to confirm the successful completion of the handover. Once the handover is complete, the UE 100 releases its connection with the previous serving cell (source cell) 121, and communication continues through the new serving cell (target cell) 122.

[0092] There are various types of handover procedures. For example, a Conditional Handover (CHO) can be defined as a handover performed by UE 100 when one or more handover execution conditions are met. In other words, in the case of a CHO, UE 100 (e.g., from source access node 106) receives a handover command with a CHO configuration indicating one or more handover execution conditions (such as RSRP, distance, and time), but UE 100 does not execute the handover command until one or more handover execution conditions are met. UE 100 may begin evaluating one or more handover execution conditions after receiving the CHO configuration and stop evaluating one or more handover execution conditions once the handover is performed.

[0093] For example, CHO configuration can be included in an RRC reconfiguration message. CHO configuration includes the configuration of (multiple) CHO candidate cells 122 generated by the candidate target access node 106B, and one or more handover execution conditions generated by the source access node 106. For example, the NTN specification allows UE 100 to trigger CHO based on a time window [T1 T2] or a distance threshold.

[0094] In a scenario where UE 100 has a running T390 timer (i.e., GNSS location expired) and subsequently receives a handover command, if UE 100 stops the T390 timer when handing over to target cell 122, UE 100 will not be synchronized by the uplink, and therefore UE 100 will be unable to transmit anything to target cell 122. Similarly, if UE 100 stops the T390 timer when performing a conditional handover, UE 100 will not be synchronized by the uplink. On the other hand, if UE 100 keeps the T390 timer running and does not notify target cell 122 of the T390 timer, UE 100 may inadvertently move to RRC idle mode or begin automatic GNSS measurements after the T390 timer expires. Furthermore, if target cell 122 is unaware of the T390 value, target cell 122 cannot schedule UE 100 during GNSS measurement gaps (i.e., when UE 100 uses GNSS radio to perform GNSS measurements).

[0095] To avoid UE 100 having to perform GNSS measurements as part of the handover process, it might be beneficial if UE 100 did not stop the T390 timer during handover or conditional handover. This would ensure that UE 100 remains uplink synchronized.

[0096] However, based on current specifications, the challenge is that target cell 122 is unaware of the T390 running in UE 100. It would be beneficial for target cell 122 to know the T390 state of UE 100, allowing it to restart T390, schedule GNSS measurement gaps, or enable automatic GNSS measurements to begin when the current T390 expires. Ultimately, if the T390 timer expires in target cell 122, it could also cause UE 100 to leave RRC connected mode.

[0097] Some example implementations address the problem of how to make target cell 122 aware of the T390 timer running in UE 100 and UE 102.

[0098] For example, based on a handover request, source cell 121 instructs target cell 122 to provide T390, and target cell 122 can be made aware of T390. For a normal handover, it seems feasible for source cell 121 to provide T390, since the handover is performed shortly thereafter. However, for a conditional handover, UE 100 can delay the handover execution, which may cause the T390 reported by source cell 121 to target cell 122 to expire (e.g., T390 may have been reset). Therefore, alternatively, for a CHO, UE 100 can (e.g., in msg3 or msg5 or an RRC connection reconfiguration complete message) indicate that T390 is in operation as part of communication with target cell 122.

[0099] In other words, for a normal (unconditional) handover, the source cell 121 can report the T390 status (e.g., operational) of UE 100 to the target cell 122 via inter-node messages. For a conditional handover, UE 100 can report its T390 status (e.g., operational) to the target cell 122 via the Uu interface during or after the CHO execution.

[0100] If the RRC connection reconfiguration message includes mobility control information and the UE is able to follow the configuration included in that message, the UE can configure the content of the RRC connection reconfiguration completion message as follows: If the target cell is an NTN cell, the UE can include the GNSS effective duration based on the remaining time of the GNSS effective duration. If the RRC connection reconfiguration message includes a GNSS positioning duration report, the UE can include the GNSS positioning duration based on the duration required for the UE to obtain its GNSS location. If T390 is operational, the UE can include, for example, the remaining value of T390. The UE can submit the RRC connection reconfiguration completion message to a lower layer for transmission.

[0101] The example implementation described below ensures a mutual understanding of T390 between UE 100 and target cell 122. The example implementation also ensures that UE 100 can continue to use uplink extension (T390) when handing over to target cell 122, that is, UE 100 maintains uplink synchronization.

[0102] Figure 2 A signal flow diagram according to an example embodiment is shown for providing the T390 state of UE 100 from source cell 121 to target cell 122. For example, source cell 121 can provide the T390 state in a handover request for a normal handover (i.e., unconditional handover) because there will be only a brief delay between the handover request and UE 100 performing the handover attempt.

[0103] Alternatively, source cell 121 may provide the T390 state of UE 100 to target cell 122 in a handover request for conditional handover, and as part of the CHO configuration, indicate to UE 100 when to provide the T390 state to target cell 122. UE 100 may then determine whether to provide the current (updated) T390 state to target cell 122 (e.g., during or after handover) based on whether the T390 state provided by source cell 121 to target cell 122 is still valid (i.e., has not been reset).

[0104] Reference Figure 2 At point 201, the access node (e.g., satellite) 106 of the control source cell 121 (i.e., the current serving cell of UE 100) transmits the T390 configuration to UE 100. The T390 configuration may include a configured value for a T390 timer for uplink transmission extension, wherein the configured value indicates the duration of the T390 timer, i.e., a time period after which T390 expires. The T390 configuration may also include an indication to enable the T390 timer for uplink transmission extension (e.g., ul-transmission extension enabled).

[0105] At point 202, when UE 100 has performed GNSS measurements, UE 100 reports to access node 106 of control source cell 121, indicating the remaining effective GNSS duration of UE 100. Based on this report, access node 106 knows when the effective GNSS duration of UE 100 expires, and when the T390 timer is started at UE 100 (because the T390 timer is started when the effective GNSS duration expires). Access node 106 also knows the duration of the T390 timer, as this duration was configured by access node 106 at point 201.

[0106] At point 203, because the effective duration of UE 100's GNSS expires (i.e., because UE 100's GNSS location becomes expired), UE 100 starts the T390 timer. When started, the T390 timer counts down from a configured value toward zero as time elapses. For example, if the configured value is 10 seconds, the T390 timer can start counting from 10 seconds and expire when the T390 timer reaches zero after 10 seconds.

[0107] At 204, the access node 106 controlling the source cell 121 determines that the UE 100 may need to switch from the source cell 121 to the target cell 122 controlled by another access node (e.g., another satellite) 106B. For example, this determination may be based on radio measurements reported by the UE 100 for the source cell 121 and / or the target cell 122.

[0108] At 205, the access node 106 of the control source cell 121 determines the state of the T390 timer of UE 100, whose GNSS effective duration has expired. The state determination may be based on a report received from UE 100 at 202.

[0109] For example, determining the state of the T390 timer may include at least one of the following: determining that the T390 timer is running (i.e., the T390 timer has been started by UE 100), determining the remaining time of the T390 timer until its expiration, or determining the start time of the T390 timer. The start time refers to the time when UE 100 starts the T390 timer.

[0110] At point 206, access node 106 of source cell 121 transmits a handover request message to access node 106B of target cell 122 to request user equipment 100 to hand over from source cell 121 to target cell 122. The handover request message includes information for preparing for handover at access node 106B of target cell 122.

[0111] The handover request message may also include information indicating the state of the T390 timer at UE 100. Alternatively, the information indicating the state of the T390 timer may be transmitted separately from the handover request message. Access node 106B receives this information. Based on this information, access node 106B controlling target cell 122 knows the state of the T390 timer at UE 100.

[0112] For example, the state of the T390 timer can include at least the remaining time of the T390 timer when the access node 106 provides information.

[0113] Alternatively or additionally, the state of the T390 timer may include at least the start time of the T390 timer and the configured value of the T390 timer.

[0114] Alternatively or additionally, the information may include at least an indication (such as a flag) indicating that the T390 timer is running at UE 100, which may enable or trigger the access node 106B of the target cell 122 to reset the T390 timer to a known value (e.g., a configured value) when UE 100 completes handover.

[0115] At point 207, access node 106B of target cell 122 transmits a handover request confirmation message to access node 106 of source cell 121. This handover request confirmation message instructs access node 106B of target cell 122 to accept the handover. The handover request confirmation message may include a handover command to be transmitted to UE 100.

[0116] At point 208, after receiving the handover request confirmation message, the access node 106 controlling the source cell 121 transmits a handover command to the UE 100 to trigger the UE 100 to perform a handover from the source cell 121 to the target cell 122. For example, the handover command may be transmitted in an RRC reconfiguration message that includes information for accessing the target cell 122 (e.g., the identifier of the target cell 122).

[0117] At point 209, the access node 106 of the control source cell 121 may optionally transmit to the UE 100 an indication of when the information indicating the state of the T390 timer was transmitted to the access node 106B of the control target cell 122. In other words, the indication may indicate a point in time when the information indicating the state of the T390 timer was transmitted to the access node 106B. This indication may be transmitted together with the handover command or separately from the handover command.

[0118] At 210, based on an indication that the UE can receive at 209, the UE 100 may optionally determine whether (e.g., during or after handover) to indicate the value of the T390 timer (e.g., the latest value) to the access node 106B controlling the target cell 122, based on whether the T390 state provided by the access node 106 of the source cell 121 to the access node 106B of the target cell 122 is still valid (i.e., the T390 state has not been reset). For example, this may be beneficial in the case of conditional handover if the UE's T390 timer is reset after the access node 106 of the source cell 121 indicates the T390 state to the access node 106B of the target cell 122 and before the handover is initiated.

[0119] At 211, based on the received handover command, UE 100 performs a handover from source cell 121 to target cell 122.

[0120] Based on the determination of 210, UE 100 may optionally indicate the value of timer T390 (e.g., the latest value) to access node 106B during or after handover (e.g., in msg3 or msg5 or RRC connection reconfiguration complete message).

[0121] Alternatively, when a handover is initiated or completed (e.g., in the case of conditional handover), UE 100 may optionally reset the T390 timer to its configured value. This ensures that the T390 timer is reset to a known value (i.e., the configured value) and avoids the signaling overhead of providing the T390 value to the target cell 122 (e.g., in msg3 or msg5).

[0122] At 212, when the handover is completed (or based on the completion of the handover), the access node 106B controlling the target cell 122 performs an action based on information indicating the state of the T390 timer of the UE 100.

[0123] For example, this action could include enabling automatic global navigation satellite system measurements at UE 100 when the T390 timer expires (or based on determining that the T390 timer of UE 100 has expired).

[0124] As another example, the action could include releasing UE 100 into RRC idle mode when the T390 timer expires (or based on determining that the T390 timer of UE 100 has expired).

[0125] As another example, the action could include resetting the T390 timer to a configured value when the handover is completed (or based on the completion of the handover). The access node 106B controlling the target cell 122 could reset the T390 timer and indicate the configured value to the UE 100 in a message (e.g., via unicast), or provide the configured value by broadcasting it and subsequently triggering a reset at the UE 100 without specifying the UE.

[0126] As another example, the action may include providing uplink resources to UE 100 to indicate the value of the T390 timer (e.g., the latest value) to access node 106B of control target cell 122 if the value of the T390 timer has not been previously received from UE 100.

[0127] As another example, the action could include a GNSS measurement gap triggered for UE 100.

[0128] In another embodiment, if the access node 106B controlling the target cell 122 does not support uplink transmission extension, the access node 106B may transmit an indication to the access node 106 controlling the source cell 121 to indicate that the access node 106B does not support uplink transmission extension. For example, the access node 106B may transmit this indication in response to receiving a T390 status from the UE 100 from the access node 106. The access node 106 controlling the source cell 121 may then trigger a new GNSS measurement at the UE 100 (to avoid the T390 timer running), or notify the UE 100 that the access node 106 needs to perform a GNSS measurement before attempting to establish a connection with the target cell 122.

[0129] Figure 3 A signal flow diagram according to an example embodiment is shown for UE 100 to provide T390 status to target cell 122 as part of conditional handover.

[0130] Reference Figure 3 At point 301, the access node (e.g., satellite) 106 of the control source cell 121 (i.e., the current serving cell of UE 100) transmits a T390 configuration to UE 100. This T390 configuration may include a configured value for a T390 timer for uplink transmission extension, wherein the configured value indicates the duration of the T390 timer, i.e., a time period after which T390 expires. The T390 configuration may also include an indication to enable the T390 timer for uplink transmission extension (e.g., ul-transmission extension enabled).

[0131] At point 302, due to the expiration of the GNSS validity period of UE 100 (i.e., because the GNSS location of UE 100 becomes expired), UE 100 starts the T390 timer. When started, the T390 timer can count down from a configured value toward zero as time elapses. For example, if the configured value is 10 seconds, the T390 timer can start counting from 10 seconds and expire when the T390 timer reaches zero after 10 seconds.

[0132] At 303, the access node 106 of the control source cell 121 determines that the UE 100 is preparing for a conditional handover, wherein one or more neighboring cells 122 are determined as candidate target cells for the conditional handover. For example, this determination may be based on radio measurements reported by the UE 100 for the source cell 121 and / or one or more neighboring cells 122.

[0133] At 304, the access node 106 of the source cell 121 transmits a handover request message to the access node 106B of the candidate target cell 122 (e.g., another satellite) to request a conditional handover of UE 100 from the source cell 121 to the candidate target cell 122. The handover request message includes information for preparing for handover at the access node 106B of the candidate target cell 122.

[0134] At position 305, access node 106B of control candidate target cell 122 transmits a handover request confirmation message to access node 106 of control source cell 121. The handover request confirmation message instructs access node 106B of control candidate target cell 122 to accept conditional handover. The handover request confirmation message may include a handover command to be transmitted to UE 100.

[0135] At 306, after receiving the handover request confirmation message, the access node 106 of the control source cell 121 transmits a CHO configuration (which includes a handover command) to the UE 100, for example, via an RRC reconfiguration message. The CHO configuration may include or indicate one or more conditions for performing the handover.

[0136] During conditional handover, UE 100 can be configured with multiple target cells and various execution conditions. For example, the NTN specification allows the UE to trigger CHO based on a time window [T1 T2] or a distance threshold.

[0137] UE 100 can transmit an RRC reconfiguration complete message to access node 106 of control source cell 121 to indicate that the CHO configuration has been successfully applied.

[0138] At 307, UE 100 detects that one or more conditions for performing a conditional handover to target cell 122 are met, and therefore UE 100 initiates a handover from source cell 121 to target cell 122.

[0139] At 308, UE 100 determines the state of its T390 timer. For example, determining the state of the T390 timer may include at least one of the following: determining that the T390 timer is running (i.e., the T390 timer has been started by UE 100), determining the remaining time of the T390 timer until its expiration, or determining the start time of the T390 timer. The start time refers to the time when UE 100 starts the T390 timer.

[0140] At 309, based on the detection that one or more conditions for performing conditional handover are met, UE 100 performs (implements) a handover from source cell 121 to target cell 122.

[0141] During or after handover, UE 100 transmits information indicating the state of UE 100's T390 timer to access node 106B controlling target cell 122. Access node 106B receives this information. Based on this information, access node 106B controlling target cell 122 knows the state of T390 timer at UE 100.

[0142] For example, the state of the T390 timer can include at least the remaining time of the T390 timer when the access node 106 provides information.

[0143] Alternatively or additionally, the state of the T390 timer may include at least the start time of the T390 timer and the configured value of the T390 timer.

[0144] Alternatively or additionally, this information may include at least an indication (such as a flag) indicating that the T390 timer is running at UE 100, which may enable or trigger access node 106B of control target cell 122 to reset the T390 timer to a known value (e.g., a configured value) when UE 100 completes handover, or provide uplink resources to UE 100 to signal the actual value of the T390 timer to access node 106B, or trigger a GNSS measurement gap for UE 100 to regain GNSS location.

[0145] At 310, when the handover is completed (or based on the completion of the handover), the access node 106B controlling the target cell 122 performs an action based on information indicating the state of the T390 timer of the UE 100.

[0146] For example, this action could include enabling automatic global navigation satellite system measurements at UE 100 when the T390 timer expires (or based on determining that the T390 timer of UE 100 has expired).

[0147] As another example, the action could include releasing UE 100 into RRC idle mode when the T390 timer expires (or based on determining that the T390 timer of UE 100 has expired).

[0148] As another example, the action could include resetting the T390 timer to a configured value when the handover is completed (or based on the completion of the handover). The access node 106B controlling the target cell 122 could reset the T390 timer and indicate the configured value to the UE 100 in a message (e.g., msg4), or provide the configured value by broadcasting the configured value and subsequently triggering a reset at the UE 100 without indicating the value specifically to the UE.

[0149] As another example, the action may include providing uplink resources to UE 100 to indicate the value of the T390 timer (e.g., the latest value) to access node 106B of control target cell 122 if the value of the T390 timer has not been previously received from UE 100.

[0150] As another example, this action could include triggering a GNSS measurement gap for UE 100.

[0151] At point 311, when a handover is initiated or completed (e.g., if UE 100 provides an indication that the T390 timer is running), UE 100 may optionally reset the T390 timer to a configured value (e.g., a configured value provided in a broadcast or msg4 from target cell 122). This ensures that the T390 timer is reset to a known value (i.e., the configured value) and avoids the signaling overhead of providing the T390 value during or after the handover. Resetting the T390 timer to a configured value may mean restarting the T390 timer from the configured value. When the T390 timer is reset to a configured value, it may begin counting down from the configured value toward zero (e.g., from 10 seconds toward zero).

[0152] Figure 4 A flowchart is shown of an example embodiment of a method for reporting the status of a timer for uplink transmission extension to target cell 122. Figure 4 The method can be derived from Figure 6 The device 600 depicted herein performs the operation. For example, device 600 may be or include a user equipment (UE) or be included in a user equipment (UE) 100. Alternatively, Figure 4 The method can be derived from Figure 7 The apparatus 700 depicted herein is executed. For example, apparatus 700 may be or include access node 104, access node 106 of the source cell 121 controlling the handover of user equipment 100, or may be included in access node 104, access node 106 of the source cell 121 controlling the handover of user equipment 100. The access node may be included in satellite 106 (e.g., eNB or gNB on satellite 106), or the access node may be a terrestrial non-terrestrial network gateway 104.

[0153] refer to Figure 4 In box 401, the state of the timer for extending the uplink transmission of user equipment 100 is determined, indicating that the effective duration of the global navigation satellite system for user equipment 100 has expired. For example, the timer could refer to the T390 timer mentioned above.

[0154] In block 402, information indicating the state of the timer of user equipment 100 is transmitted to access node 106B of target cell 122 that controls the handover of user equipment 100.

[0155] As an example, the state of a timer can include at least the remaining time of the timer.

[0156] Alternatively or additionally, the state of a timer may include at least the timer's start time and the timer's configured value.

[0157] Alternatively or additionally, determining the state of a timer may include at least determining that the timer is running, wherein the information may include at least an indication that the timer is running.

[0158] This instruction can cause (or be configured to) the access node 106B controlling the target cell 122 to reset the timer to the configured value when the handover is complete.

[0159] Alternatively or additionally, the indication may cause (or be configured to) enable the access node 106B of the target cell 122 to provide uplink resources to the user equipment 100 to indicate the value of the timer to the access node 106B of the target cell 122.

[0160] Information indicating the state of the timer can be transmitted by the user equipment 100 during or after a handover. For example, in this case, the handover can be a conditional handover. When the handover is initiated or completed, the timer can be reset to the configured value.

[0161] Alternatively, information indicating the state of the timer can be transmitted by the access node 106 of the source cell 121 controlling the handover of user equipment 100. In this case, the information can be transmitted, for example, in a handover request message used to request handover. In this case, the handover can be a normal handover (i.e., an unconditional handover) or a conditional handover. In other words, the handover request message can be used for a normal handover, or the handover request message can be a conditional handover request message used for a conditional handover. An indication of when information is transmitted to the access node 106B controlling the target cell 122 can be transmitted to user equipment 100, wherein the indication transmitted to user equipment 100 can enable user equipment 100 to determine whether (e.g., during or after handover) to indicate the value of the timer to the access node 106B controlling the target cell 122.

[0162] Figure 5 A flowchart illustrating an example embodiment of a method for reporting the status of a timer for uplink transmission extension to target cell 122 is shown. The method can be... Figure 7 The apparatus 700 depicted herein is executed. For example, apparatus 700 may be or include access node 104, access node 106B of the target cell 122 controlling the handover of user equipment 100, or may be included in access node 104, access node 106B of the target cell 122 controlling the handover of user equipment 100. The access node may be included in satellite 106B (e.g., eNB or gNB on satellite 106B), or the access node may be a terrestrial non-terrestrial network gateway 104.

[0163] refer to Figure 5In block 501, information indicating the status of a timer for an extended uplink transmission of user equipment 100 is received from the device, indicating that the effective duration of the global navigation satellite system (GNSS) for user equipment 100 has expired. For example, the timer could refer to the T390 timer described above.

[0164] For example, information can be received from user equipment 100 during or after the handover.

[0165] As another example, the information can be received in a handover request message from access node 106 of source cell 121 that controls the handover.

[0166] In box 502, an action is performed based on this information, wherein the action includes one of the following: enabling automatic global navigation satellite system measurements at user equipment 100 when the timer expires (or based on determining that the timer of user equipment 100 has expired); releasing user equipment 100 into radio resource control idle mode when the timer expires (or based on determining that the timer of user equipment 100 has expired); resetting the timer to the configured value when the handover is completed (or based on the completion of the handover); providing uplink resources to user equipment 100 to indicate the timer value to access node 106B of control target cell 122; or triggering a global navigation satellite system measurement gap for user equipment 100.

[0167] As an example, the state of a timer can include at least the remaining time of the timer.

[0168] Alternatively or additionally, the state of a timer may include at least the timer's start time and the timer's configured value.

[0169] Alternatively or additionally, this information may include at least an indication that the timer is running.

[0170] The above text uses Figures 2 to 5 The described blocks, related functions, and information exchanges (messages) are not in absolute chronological order, and some of them may be executed simultaneously or in a different order than described. Other functions may also be executed between or within them, and other information may be sent and / or other rules may be applied. Some blocks or parts of blocks or one or more messages may also be omitted or replaced with the corresponding blocks or parts of blocks or one or more messages.

[0171] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where a list of two or more elements is connected by “and” or “or”, means at least one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0172] Figure 6 The illustration includes examples for performing one or more of the above-described example embodiments (e.g., Figure 4 Examples of devices 600 that are components of a method. For example, device 600 may be a device such as user equipment (UE) 100, 102, or a device that includes or is included in user equipment (UE) 100, 102.

[0173] Device 600 may include circuitry or chipsets suitable for implementing one or more of the example embodiments described above. For example, device 600 may include at least one processor 610. At least one processor 610 interprets instructions (e.g., computer program instructions) and processes data. At least one processor 610 may include one or more programmable processors. At least one processor 610 may include programmable hardware with embedded firmware and may alternatively or additionally include one or more application-specific integrated circuits (ASICs).

[0174] At least one processor 610 is coupled to at least one memory 620. The at least one processor is configured to read data from and write data to at least one memory 620. At least one memory 620 may include one or more memory cells. Memory cells may be volatile or non-volatile. It should be noted that one or more cells of non-volatile memory and one or more cells of volatile memory may be present, or alternatively, one or more cells of non-volatile memory, or alternatively, one or more cells of volatile memory. Volatile memory may be, for example, random access memory (RAM), dynamic random access memory (DRAM), or synchronous dynamic random access memory (SDRAM). Non-volatile memory may be, for example, read-only memory (ROM), programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), flash memory, optical storage, or magnetic storage. Generally, memory may be referred to as a non-transient computer-readable medium. As used herein, the term "non-transient" is a limitation of the medium itself (i.e., tangible, not tactile), not a limitation of data storage persistence (e.g., RAM versus ROM). At least one memory 620 stores computer-readable instructions that are executed by at least one processor 610 to perform one or more of the example embodiments described above. For example, non-volatile memory stores computer-readable instructions, and at least one processor 610 uses volatile memory for temporary storage of data and / or instructions to execute instructions. Computer-readable instructions may refer to computer program code.

[0175] Computer-readable instructions may be pre-stored in at least one memory 620, or alternatively or additionally, they may be received by the device via an electromagnetic carrier signal and / or copied from a physical entity such as a computer program product. Execution of the computer-readable instructions by at least one processor 610 causes the device 600 to perform one or more of the methods and / or blocks described in the example embodiments above. That is, at least one processor and at least one memory storing the instructions can provide components for providing or causing execution of any of the methods and / or blocks described above.

[0176] In the context of this document, "memory" or "computer-readable medium" can be any non-transient medium or component that can contain, store, communicate, propagate, or transmit instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer. As used herein, the term "non-transient" is a limitation on the medium itself (i.e., tangible, not tactile) and not on the persistence of data storage (e.g., RAM versus ROM).

[0177] The device 600 may also include or be connected to the input unit 630. The input unit 630 may include one or more interfaces for receiving input. The one or more interfaces may include, for example, one or more temperature, motion and / or orientation sensors, one or more cameras, one or more accelerometers, one or more microphones, one or more buttons and / or one or more touch detection units. In addition, the input unit 630 may include interfaces to which external devices can be connected.

[0178] The device 600 may also include an output unit 640. The output unit may include or be connected to one or more displays capable of displaying visual content, such as a light-emitting diode (LED) display, a liquid crystal display (LCD), and / or a liquid crystal on silicon (LCoS) display. The output unit 640 may also include one or more audio outputs. The one or more audio outputs may be, for example, speakers.

[0179] Device 600 also includes a connection unit 650. Connection unit 650 enables wireless connectivity to one or more external devices. Connection unit 650 includes at least one transmitter and at least one receiver that can be integrated into or connected to device 600. The at least one transmitter includes at least one transmitting antenna, and the at least one receiver includes at least one receiving antenna. Connection unit 650 may include an integrated circuit or a set of integrated circuits providing wireless communication capabilities to device 600. Alternatively, the wireless connection may be a hardwired application-specific integrated circuit (ASIC). Connection unit 650 may also provide components for performing at least some blocks or functions of one or more of the example embodiments described above. Connection unit 650 may include one or more components controlled by a corresponding control unit, such as: a power amplifier, a digital front-end (DFE), an analog-to-digital converter (ADC), a digital-to-analog converter (DAC), a frequency converter, a (de)modulator, and / or encoder / decoder circuitry.

[0180] It should be noted that device 600 may further include Figure 6 Various components are not shown. These components can be hardware components and / or software components.

[0181] Figure 7 The illustration includes examples for performing one or more of the above-described example embodiments (e.g., Figure 4 or Figure 5 Examples of apparatus 700 are components of the method. For example, apparatus 700 may be or include access nodes 104 and 106 of the target cell 122 for controlling the handover of user equipment 100, or may be included in access nodes 104 and 106 of the target cell 122 for controlling the handover of user equipment 100. Access nodes may be included in satellite 106 (e.g., eNB or gNB on satellite 106), or access nodes may be terrestrial-based non-terrestrial gateways 104.

[0182] Apparatus 700 may include, for example, a circuit system or chipset suitable for implementing one or more of the example embodiments described above. Apparatus 700 may be an electronic device including one or more electronic circuit systems. Apparatus 700 may include a communication control circuit system 710, such as at least one processor, and at least one memory 720 storing instructions 722, which, when executed by the at least one processor, cause apparatus 700 to perform one or more of the example embodiments described above. Such instructions 722 may, for example, include computer program code (software). At least one processor and at least one memory storing instructions may provide components for providing or causing execution of any of the methods and / or blocks described above.

[0183] A processor is coupled to memory 720. The processor is configured to read data from memory 720 and write data to memory 720. Memory 720 may include one or more memory cells. Memory cells may be volatile or non-volatile. It should be noted that one or more cells of non-volatile memory and one or more cells of volatile memory may be present, or alternatively, one or more cells of non-volatile memory, or alternatively, one or more cells of volatile memory. Volatile memory may be, for example, random access memory (RAM), dynamic random access memory (DRAM), or synchronous dynamic random access memory (SDRAM). Non-volatile memory may be, for example, read-only memory (ROM), programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), flash memory, optical storage, or magnetic storage devices. Generally, memory may be referred to as a non-transient computer-readable medium. As used herein, the term "non-transient" is a limitation of the medium itself (i.e., tangible, not tactile), not a limitation of data storage persistence (e.g., RAM versus ROM). Memory 720 stores computer-readable instructions that are executed by the processor. For example, non-volatile memory stores computer-readable instructions, and the processor uses volatile memory for temporary storage of data and / or instructions to execute instructions.

[0184] Computer-readable instructions may be pre-stored in memory 720, or alternatively or additionally, they may be received by the device via an electromagnetic carrier signal and / or copied from a physical entity such as a computer program product. Execution of the computer-readable instructions causes the device 700 to perform one or more of the functions described above.

[0185] The memory 720 can be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and / or removable memory. The memory may include a configuration database for storing configuration data, such as a current list of neighboring cells, and in some example embodiments, the memory includes the structure of frames used in detected neighboring cells.

[0186] The device 700 may also include or be connected to a communication interface 730 (such as a radio unit), which includes hardware and / or software for establishing a communication connection with one or more wireless communication devices according to one or more communication protocols. The communication interface 730 includes at least one transmitter (Tx) and at least one receiver (Rx) that can be integrated into or connected to the device 700. The communication interface 730 may provide components for performing some blocks and / or functions (e.g., transmitting and receiving) of one or more of the above-described example embodiments. The communication interface 730 may include one or more components controlled by a corresponding control unit, such as: a power amplifier, a digital front end (DFE), an analog-to-digital converter (ADC), a digital-to-analog converter (DAC), a frequency converter, a (de)modulator, and / or an encoder / decoder circuit system.

[0187] Communication interface 730 provides the device with radio communication capabilities for communication within a wireless communication network. The communication interface may, for example, provide a radio interface to one or more UEs 100, 102. Device 700 may also include or connect to another interface toward core network 110 (such as a network coordinator device or AMF), and / or connect to other access nodes in the wireless communication network.

[0188] The apparatus 700 may also include a scheduler 740 configured to allocate radio resources. The scheduler 740 may be configured together with the communication control circuitry system 710 or may be configured separately.

[0189] It should be noted that the device 700 may further include Figure 7 Various components are not shown. These components can be hardware components and / or software components.

[0190] As used in this application, the term "circuit system" may refer to one or more or all of the following: a) a hardware circuit implementation only (such as an implementation only in analog and / or digital circuits); and b) a combination of hardware circuits and software, such as (where applicable): i) a combination of analog and / or digital hardware circuits with software / firmware, and ii) any part of a hardware processor having software (including digital signal processors, software, and memory that work together to enable a device such as a mobile phone to perform various functions); and c) hardware circuits and / or processors that require software (e.g., firmware) for operation, such as a microprocessor or a portion thereof, but which may be absent when operation is not required.

[0191] This definition of circuit system applies to all uses of the term in this application (including any claims). As another example, as used herein, the term circuit system also covers implementations of hardware circuitry or processors (or processors) or a portion thereof and their accompanying software and / or firmware. For example, and if applicable to a particular claim element, the term circuit system also covers baseband integrated circuits or processor integrated circuits for mobile devices, or similar integrated circuits in servers, cellular network devices, or other computing or network devices.

[0192] The techniques and methods described herein can be implemented through various components. For example, these techniques can be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or combinations thereof. For hardware implementations, the apparatus(s) of the example embodiments can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), graphics processing units (GPUs), processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or combinations thereof. For firmware or software, the implementation can be executed by a module of at least one chipset (e.g., processes, functions, etc.) performing the functions described herein. Software code can be stored in memory cells and executed by a processor. Memory cells can be implemented within or outside the processor. In the latter case, it can be communicatively coupled to the processor via various components known in the art. Furthermore, as those skilled in the art will understand, the components of the systems described herein can be rearranged and / or supplemented by additional components to facilitate implementation of the various aspects described herein, and they are not limited to the precise configurations illustrated in the given figures.

[0193] It will be apparent to those skilled in the art that, with advancements in technology, the inventive concept can be implemented in various ways within the scope of the claims. Embodiments are not limited to the exemplary embodiments described above, but may vary within the scope of the claims. Therefore, all words and expressions should be interpreted broadly, and they are intended to illustrate rather than limit the embodiments.

[0194] Furthermore, the various implementations of this disclosure can be described with reference to the following terms, and their features can be combined in any reasonable manner.

[0195] Clause 1. An apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: determine the state of a timer for an uplink transmission extension of a user equipment, wherein the global navigation satellite system effective duration of the user equipment has expired; and transmit information indicating the state of the timer of the user equipment to an access node of a target cell controlling the handover of the user equipment.

[0196] Clause 2. The apparatus according to Clause 1, wherein the state of the timer includes at least the remaining time of the timer.

[0197] Clause 3. The apparatus according to any of the preceding clauses, wherein the state of the timer includes at least the start time of the timer and the configured value of the timer.

[0198] Clause 4. The apparatus according to any of the preceding clauses, wherein determining the state of the timer includes at least determining that the timer is running, wherein the information includes at least an indication that the timer is running.

[0199] Clause 5. The apparatus according to Clause 4, wherein the instruction causes the access node controlling the target cell to reset a timer to a configured value when the handover is completed.

[0200] Clause 6. An apparatus according to any one of Clauses 4 to 5, wherein instructing an access node controlling the target cell to provide uplink resources to a user equipment to instruct the access node controlling the target cell to indicate the value of a timer.

[0201] Clause 7. An apparatus according to any of the preceding clauses, wherein the apparatus is a user equipment, wherein information indicating the state of the timer is transmitted during or after a switching operation.

[0202] Clause 8. The apparatus pursuant to Clause 7 is also configured to: reset the timer to the configured value when the switch is initiated or completed.

[0203] Clause 9. A device pursuant to any of Clauses 7 to 8, wherein the switching is a conditional switching.

[0204] Clause 10. An apparatus according to any one of Clauses 1 to 6, wherein the apparatus is an access node of the source cell controlling the handover of user equipment.

[0205] Clause 11. The apparatus according to Clause 10, wherein information indicating the state of the timer is transmitted in a switching request message for requesting a switching.

[0206] Clause 12. The apparatus according to any one of Clauses 10 to 11 is further configured to: transmit to the user equipment an indication of when information is transmitted to the access node of the target cell, wherein the indication transmitted to the user equipment causes the user equipment to determine whether to indicate the value of a timer to the access node of the target cell.

[0207] Clause 13. An access node for a target cell controlling the handover of a user equipment, the access node comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the access node to at least: receive from means information indicating the state of a timer for an extended uplink transmission for the user equipment, the global navigation satellite system (GNSS) effective duration of the user equipment having expired; and perform an action based on the information, wherein the action comprises one of: enabling automatic GNSS measurements at the user equipment when the timer expires; releasing the user equipment to a radio resource control idle mode when the timer expires; resetting the timer to a configured value when the handover is completed; providing uplink resources to the user equipment to indicate the value of the timer to the access node controlling the target cell; or triggering a GNSS measurement gap for the user equipment.

[0208] Clause 14. For access nodes pursuant to Clause 13, the state of the timer includes at least the remaining time of the timer.

[0209] Clause 15. An access node pursuant to any of Clauses 13 to 14, wherein the state of the timer includes at least the start time of the timer and the configured value of the timer.

[0210] Clause 16. An access node pursuant to any of Clauses 13 to 15, wherein the information includes at least an indication that a timer is running.

[0211] Clause 17. An access node pursuant to any of Clauses 13 to 16, wherein information is received from the user equipment during or after handover.

[0212] Clause 18. An access node pursuant to any of Clauses 13 to 16, wherein information is received in a handover request message from the access node of the source cell controlling the handover.

[0213] Clause 19. An apparatus comprising: a component for determining the state of a timer for an uplink transmission extension of a user equipment, wherein the global navigation satellite system effective duration of the user equipment has expired; and a component for transmitting information indicating the state of the timer of the user equipment to an access node of a target cell controlling a handover of the user equipment.

[0214] Clause 20. An access node for a target cell controlling the handover of a user equipment (UE), the access node comprising: a component for receiving information from means indicating the state of a timer for an uplink transmission extension for the UE, the UE's Global Navigation Satellite System (GNSS) effective duration having expired; and a component for performing an action based on the information, wherein the action comprises one of: enabling automatic GNSS measurements at the UE when the timer expires; releasing the UE to a Radio Resource Control (RRS) idle mode when the timer expires; resetting the timer to a configured value when the handover is completed; providing uplink resources to the UE to indicate the timer value to the access node controlling the target cell; or triggering a GNSS measurement gap for the UE.

[0215] Clause 21. A method comprising: determining the state of a timer for an uplink transmission extension of a user equipment, wherein the global navigation satellite system effective duration of the user equipment has expired; and transmitting information indicating the state of the timer of the user equipment to an access node of a target cell controlling a handover of the user equipment.

[0216] Clause 22. A method performed by an access node of a target cell controlling a handover of a user equipment, the method comprising: receiving from means information indicating the state of a timer for an uplink transmission extension of the user equipment, the user equipment's Global Navigation Satellite System (GNSS) effective duration having expired; and performing an action based on the information, wherein the action comprises one of: enabling automatic GNSS measurements at the user equipment when the timer expires; releasing the user equipment to a Radio Resource Control (RFC) idle mode when the timer expires; resetting the timer to a configured value when the handover is completed; providing uplink resources to the user equipment to indicate the timer value to the access node controlling the target cell; or triggering a GNSS measurement gap for the user equipment.

[0217] Clause 23. A non-transitory computer-readable medium comprising program instructions that, when executed by a device, cause the device to perform at least the following operations: determine the state of a timer for an uplink transmission extension of a user equipment, wherein the effective duration of the user equipment's Global Navigation Satellite System (GNSS) has expired; and transmit information indicating the state of the user equipment's timer to an access node of a target cell controlling the handover of the user equipment.

[0218] Clause 24. A non-transitory computer-readable medium comprising program instructions that, when executed by an access node of a target cell controlling a handover of a user equipment, cause the access node to perform at least the following operations: receive from a device information indicating the state of a timer for an uplink transmission extension of the user equipment, the effective duration of the user equipment's Global Navigation Satellite System (GNSS) data having expired; and perform an action based on the information, wherein the action includes one of: enabling automatic GNSS measurements at the user equipment when the timer expires; releasing the user equipment to a Radio Resource Control (RFC) idle mode when the timer expires; resetting the timer to a configured value when the handover is completed; providing uplink resources to the user equipment to indicate the value of the timer to the access node controlling the target cell; or triggering a GNSS measurement gap for the user equipment.

Claims

1. An apparatus for communication, comprising at least one processor and at least one memory storing instructions, said instructions, when executed by said at least one processor, causing the apparatus to at least: Determine the state of the timer used for uplink transmission extension of the user equipment, where the effective duration of the user equipment's Global Navigation Satellite System (GNSS) has expired; and Information indicating the state of the timer of the user equipment is transmitted to the access node of the target cell that controls the handover of the user equipment.

2. The apparatus of claim 1, wherein the state of the timer includes at least the remaining time of the timer.

3. The apparatus of claim 1 or 2, wherein the state of the timer includes at least the start time of the timer and the configured value of the timer.

4. The apparatus of claim 1 or 2, wherein determining the state of the timer includes at least determining that the timer is running. The information mentioned therein includes at least an indication that the timer is running.

5. The apparatus of claim 4, wherein the indication causes the access node controlling the target cell to reset the timer to a configured value when the handover is completed.

6. The apparatus of claim 4, wherein the indication causes the access node controlling the target cell to provide uplink resources to the user equipment to indicate the value of the timer to the access node controlling the target cell.

7. The apparatus according to claim 1 or 2, wherein the apparatus is the user equipment. The information indicating the state of the timer is transmitted during or after the switching.

8. The apparatus according to claim 7, further comprising: When the switch is initiated or completed, the timer is reset to the configured value.

9. The apparatus according to claim 7, wherein the switching is a conditional switching.

10. The apparatus according to claim 1 or 2, wherein the apparatus is an access node of the source cell for controlling the handover of the user equipment.

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