Apparatus and method for power control for handover

Abstract

Embodiments of the present disclosure provide a solution for handover power control. In one solution, a terminal device adjusts a transmit power for a target cell based on a remaining time associated with a determination of a result of a handover from a source cell to the target cell; and transmits a message indicating the handover to the target cell using the adjusted transmit power.

Description

Technical Field

[0001] The exemplary embodiments disclosed herein relate generally to the field of communication technology, and more specifically to devices and methods for power control for handover (HO). Background Technology

[0002] Non-terrestrial networks (NTNs) refer to networks or network segments that utilize radio frequency (RF) resources mounted on satellite or unmanned aircraft systems (UAS). NTNs provide ubiquitous and resilient wireless services that extend beyond the coverage of terrestrial networks. The 3rd Generation Partnership Project (3GPP) has been working on NTN standardization since the advent of 5G communication systems. It is anticipated that NTNs will be fully integrated with terrestrial networks (TNs) in the sixth generation (6G). Summary of the Invention

[0003] Generally, embodiments of this disclosure provide apparatus and methods for power control during handover.

[0004] In a first aspect, a terminal device is provided, the terminal device comprising: a processor configured to cause the terminal device to: adjust a transmission power for the target cell based on a remaining time associated with a determination of the result of a handover from a source cell to a target cell; and transmit a message indicating the handover to the target cell using the adjusted transmission power.

[0005] In a second aspect, a network device is provided, comprising: a processor configured to cause the network device providing a target cell to: receive from a terminal device a message indicating a handover from a source cell to the target cell, and wherein the message is transmitted using a transmit power adjusted based on a remaining time associated with a determination of the result of the handover.

[0006] In a third aspect, a network device is provided, comprising: a processor configured to cause the network device providing a source cell to: send an indication of a duration associated with a transmission power adjustment for sending a message indicating handover from the source cell to a target cell.

[0007] In a fourth aspect, a terminal device is provided, the terminal device comprising: a processor configured to cause the terminal device to: receive from a source cell information about an adjustment state of power control for a target cell; determine, based on the information, a transmission power for the target cell; and use the transmission power to send to the target cell a message indicating a transfer from the source cell to the target cell.

[0008] In a fifth aspect, a network device is provided, the network device comprising: a processor configured to cause the network device providing a source cell to: send information to a terminal device regarding an adjustment state for power control of a target cell, wherein the terminal device will perform a handover from the source cell to the target cell.

[0009] In a sixth aspect, a network device is provided, the network device comprising: a processor configured to cause the network device providing a target cell to: receive from a terminal device a message indicating a handover from a source cell to the target cell, wherein the message is transmitted using a transmit power determined based on information from the source cell regarding an adjustment state for power control of the target cell.

[0010] In a seventh aspect, a terminal device is provided, the terminal device comprising: a processor configured to cause the terminal device to: receive from a source cell information about a scaling factor for a target cell, the scaling factor being applied to a path loss estimate for the target cell; determine a transmission power for the target cell based on the information and the path loss estimate; and use the transmission power to transmit to the target cell a message indicating a handover from the source cell to the target cell.

[0011] In an eighth aspect, a network device is provided, the network device comprising: a processor configured to cause the network device providing a source cell to: send information to a terminal device about a scaling factor for a target cell, the scaling factor being applied to a path loss estimate for the target cell, wherein the terminal device will perform a handover from the source cell to the target cell.

[0012] In a ninth aspect, a network device is provided, the network device comprising: a processor configured to cause the network device providing a target cell to: receive from a terminal device a message indicating a handover from a source cell to the target cell, wherein the message is transmitted using a transmit power determined based on information from the source cell regarding a scaling factor for the target cell, the scaling factor being applied to a path loss estimate for the target cell.

[0013] In a tenth aspect, a communication method performed by a terminal device is provided. The method includes: adjusting a transmission power for the target cell based on remaining time associated with a determination of a result of handover from a source cell to a target cell; and transmitting a message indicating the handover to the target cell using the adjusted transmission power.

[0014] In an eleventh aspect, a communication method performed by a network device is provided. The method includes: receiving from a terminal device a message indicating a handover from a source cell to a target cell, and wherein the message is transmitted using a transmission power adjusted based on remaining time associated with a determination of the result of the handover.

[0015] In a twelfth aspect, a communication method performed by a network device is provided. The method includes: sending to a terminal device an indication of a duration associated with a transmission power adjustment for sending a message indicating handover from a source cell to a target cell.

[0016] In a thirteenth aspect, a communication method performed by a terminal device is provided. The method includes: receiving information from a source cell regarding an adjustment state of power control for a target cell; determining a transmission power for the target cell based on the information; and using the transmission power to send a message to the target cell indicating a transfer from the source cell to the target cell.

[0017] In a fourteenth aspect, a communication method performed by a network device is provided. The method includes: sending information to a terminal device regarding an adjustment state for power control of a target cell, wherein the terminal device will perform a handover from the source cell to the target cell.

[0018] In a fifteenth aspect, a communication method performed by a network device is provided. The method includes: receiving from a terminal device a message indicating a handover from a source cell to a target cell, wherein the message is transmitted using a transmission power determined based on information from the source cell regarding an adjustment state for power control of the target cell.

[0019] In a sixteenth aspect, a communication method performed by a terminal device is provided. The method includes: receiving from a source cell information about a scaling factor for a target cell, the scaling factor being applied to a path loss estimate for the target cell; determining a transmission power for the target cell based on the information and the path loss estimate; and using the transmission power to send to the target cell a message indicating a handover from the source cell to the target cell.

[0020] In a seventeenth aspect, a communication method performed by a network device is provided. The method includes: sending information to a terminal device about a scaling factor for a target cell, the scaling factor being applied to a path loss estimate for the target cell, wherein the terminal device will perform a handover from a source cell to the target cell.

[0021] In an eighteenth aspect, a communication method performed by a network device is provided. The method includes: receiving from a terminal device a message indicating handover from a source cell to a target cell, wherein the message is transmitted using a transmission power determined based on information from the source cell regarding a scaling factor for the target cell, the scaling factor being applied to a path loss estimate for the target cell.

[0022] In a nineteenth aspect, a computer-readable medium is provided that stores instructions that, when executed on at least one processor, cause the at least one processor to perform the method according to the tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth, sixteenth, seventeenth, or eighteenth aspects.

[0023] Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0024] The above and other objects, features and advantages of this disclosure will become more apparent from a more detailed description of some exemplary embodiments thereof in the accompanying drawings, wherein: Figure 1 An example communication environment in which an example implementation of the present disclosure can be carried out is illustrated; Figure 2A and Figure 2B Schematic diagrams illustrating non-terrestrial network scenarios with different payload types according to some embodiments of this disclosure are shown; Figures 3A to 3D Schematic diagrams illustrating intra-satellite and inter-satellite handover according to some embodiments of this disclosure are shown; Figure 4 An example signaling flow for power control for handover according to some embodiments of this disclosure is illustrated; Figure 5 A signaling flow for another example of power control for handover according to some embodiments of this disclosure is illustrated; Figure 6 A signaling flow for handover power control according to some embodiments of this disclosure is illustrated in yet another example; Figure 7A Flowcharts illustrating methods implemented at a terminal device according to some embodiments of this disclosure are shown; Figure 7BFlowcharts illustrating methods implemented at network devices according to some embodiments of this disclosure are shown; Figure 7C A flowchart illustrating another method implemented at a network device according to some embodiments of this disclosure is shown; Figure 8A Flowcharts illustrating methods implemented at a terminal device according to some embodiments of this disclosure are shown; Figure 8B Flowcharts illustrating methods implemented at network devices according to some embodiments of this disclosure are shown; Figure 8C A flowchart illustrating another method implemented at a network device according to some embodiments of this disclosure is shown; Figure 9A Flowcharts illustrating methods implemented at a terminal device according to some embodiments of this disclosure are shown; Figure 9B Flowcharts illustrating methods implemented at network devices according to some embodiments of this disclosure are shown; Figure 9C A flowchart illustrating another method implemented at a network device according to some embodiments of this disclosure is shown; Figure 10 A simplified block diagram of an apparatus suitable for implementing an example embodiment of the present disclosure is shown.

[0025] Throughout the accompanying drawings, the same or similar reference numerals denote the same or similar elements. Detailed Implementation

[0026] The principles of this disclosure will now be described with reference to some exemplary embodiments. It should be understood that these embodiments are described for illustrative purposes only and to help those skilled in the art to understand and implement this disclosure, and do not imply any limitation on the scope of this disclosure. The embodiments described herein can be implemented in various ways other than those described below.

[0027] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0028] As used herein, the term "terminal device" refers to any device with wireless or wired communication capabilities. Examples of terminal devices include, but are not limited to: user equipment (UE); personal computers; desktop computers; mobile phones; cellular phones; smartphones; personal digital assistants (PDAs); portable computers; tablets; wearable devices; Internet of Things (IoT) devices; Ultra-reliable and Low Latency Communication (URLLC) devices; Internet of Everything (IoE) devices; machine-type communication (MTC) devices; devices on vehicles for V2X communication, where X refers to pedestrians, vehicles, or infrastructure / networks; devices for Integrated Access and Backhaul (IAB); spacecraft or aerospace vehicles in non-terrestrial networks (NTNs), including satellites and high-altitude platforms (HAPs) covering Unmanned Aircraft Systems (UAS); and different types of reality (such as Augmented Reality (AR), Mixed Reality (MR)). Extended Reality (XR) devices, including those for Virtual Reality (VR) and Virtual Reality (VR); unmanned aerial vehicles (UAVs), often referred to as drones (aircraft without human pilots); devices on high-speed trains (HSTs); or image capture devices such as digital cameras and sensors; gaming devices; music storage and playback equipment; or internet devices enabling wireless or wired internet access and browsing. "Terminal devices" may also have "multicast / broadcast" capabilities to support public safety and mission-critical applications, V2X applications, transparent IPv4 / IPv6 multicast delivery, IPTV, smart TV, radio services, wireless software delivery, group communication, and IoT applications. "Terminal devices" may also incorporate one or more Subscriber Identity Modules (SIMs), a situation known as multi-SIM. The term "terminal device" is used interchangeably with UE, mobile station, subscriber station, mobile terminal, user terminal, or wireless device.

[0029] The term "network device" refers to a device that provides or hosts a cell or coverage area for terminal devices to communicate. Examples of network devices include, but are not limited to, NodeBs (or NBs), evolved NodeBs (eNodeBs or eNBs), next-generation NodeBs (gNBs), transmission reception points (TRPs), remote radio units (RRUs), radioheads (RHs), remote radio heads (RRHs), IAB nodes, low-power nodes (such as femtonodes and piconodes), reconfigurable intelligent surfaces (RISs), etc.

[0030] Terminal devices or network devices may have artificial intelligence (AI) or machine learning capabilities. Terminal devices or network devices typically include models that have been trained on specific functions based on a large amount of collected data and can be used to predict some information.

[0031] Terminal or network devices can operate within several frequency ranges, such as FR1 (e.g., 450MHz to 6000MHz), FR2 (e.g., 24.25GHz to 52.6GHz), bands greater than 100GHz, and terahertz (THz), Ku band (e.g., 12GHz to 18GHz), and Ka band (e.g., 26GHz to 40GHz). Terminal or network devices can also operate on licensed / unlicensed / shared spectrum. In Multi-Radio Dual Connectivity (MR-DC) applications, terminal devices can be connected to more than one network device. Terminal or network devices can operate in full-duplex, flexible-duplex, and cross-division duplex modes.

[0032] The embodiments of this disclosure can be executed in test equipment (e.g., signal generator, signal analyzer, spectrum analyzer, network analyzer, test terminal equipment, test network equipment, channel simulator). In some embodiments, the terminal equipment can be connected to a first network equipment and a second network equipment. One of the first network equipment and the second network equipment can be a master node, and the other can be a slave node. The first network equipment and the second network equipment can use different Radio Access Technologies (RATs). In some embodiments, the first network equipment can be a first RAT device, and the second network equipment can be a second RAT device. In some embodiments, the first RAT device is an eNB, and the second RAT device is a gNB. Information related to different RATs can be sent to the terminal equipment from at least one of the first network equipment or the second network equipment. In some embodiments, first information can be sent from the first network equipment to the terminal equipment, and second information can be sent from the second network equipment directly or via the first network equipment to the terminal equipment. In some embodiments, information configured by the second network equipment and related to the configuration of the terminal equipment can be sent from the second network equipment via the first network equipment. Information configured by the second network device and related to the reconfiguration of the terminal device can be sent directly from the second network device or via the first network device to the terminal device.

[0033] As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term “comprising” and its variations should be understood as open terms meaning “including, but not limited to.” The term “based on” should be understood as “at least partially based on.” The terms “one implementation” and “implementation” should be understood as “at least one implementation.” The term “another implementation” should be understood as “at least one other implementation.” The terms “first,” “second,” etc., may refer to different or the same objects. Other explicit and implicit definitions are given below.

[0034] In some examples, values, processes, or devices are described as “best,” “lowest,” “highest,” “minimum,” “maximum,” etc. It should be understood that such descriptions are intended to indicate that a choice can be made among many alternative functionalities used, and that such a choice is not necessarily better, smaller, higher, or otherwise preferred than other choices.

[0035] As used herein, the terms “resource,” “transmission resource,” “uplink resource,” or “downlink resource” can refer to any resource used to perform communication, such as a resource in the time domain, a resource in the frequency domain, a resource in the spatial domain, a resource in the code domain, or any other resource used to implement communication. In the following, unless explicitly stated otherwise, resources in both the frequency and time domains will be used as examples of transmission resources to describe some exemplary embodiments of this disclosure. It should be noted that the exemplary embodiments of this disclosure are equally applicable to other resources in other domains.

[0036] Example Environment Figure 1 A schematic diagram illustrating an example communication environment 100 in which an example embodiment of the present disclosure may be implemented is shown. In communication environment 100, terminal device 110 can communicate with one or more network devices ( Figure 1 (Not shown in the image) Communication. In Figure 1 In the example, terminal device 110 can be a UE, and network device can be a base station serving the UE.

[0037] The communication environment 100 may further include a source cell 120 and a target cell 130. The terminal device 110 can perform a handover from the source cell 120 to the target cell 130. In some embodiments, the source cell 120 may be provided by one network device, and the target cell 130 may be provided by another network device. Alternatively, the source cell 120 and the target cell 130 may be provided by the same network device.

[0038] It should be understood that Figure 1 The number of devices and their connections shown are for illustrative purposes only and do not imply any limitation. Communication environment 100 may include any suitable number of devices configured to implement the example embodiments of this disclosure. Although not shown, it should be understood that one or more additional devices may be deployed in communication environment 100.

[0039] In the following description, for illustrative purposes, some example implementations are described in which the terminal device 110 operates as a UE and the network device operates as a gNB. However, in some example implementations, the operations described in connection with the terminal device may be implemented at the network device or other devices.

[0040] The link from the network device to the terminal device 110 is called a downlink (DL), and the link from the terminal device 110 to the network device is called an uplink (UL). In the DL, the network device is the transmitting (TX) device (or sender), and the terminal device 110 is the receiving (RX) device (or receiver). In the UL, the terminal device 110 is the TX device (or sender), and the network device is the RX device (or receiver). In communication, the terminal device 110 can perform uplink transmissions with the network device, such as physical uplink shared channel (PUSCH) transmissions.

[0041] The communications in communication environment 100 may conform to any suitable standard, including but not limited to Global System for Mobile Communication (GSM), Long Term Evolution (LTE), LTE-Evolution, LTE-Advanced (LTE-A), New Radio (NR), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), GSM EDGE Radio Access Network (GERAN), Machine Type Communication (MTC), etc. The embodiments of this disclosure may be implemented according to any generation of communication protocols currently known or to be developed in the future. Examples of communication protocols include, but are not limited to, first-generation (1G) communication protocols, second-generation (2G) communication protocols, 2.5G communication protocols, 2.75G communication protocols, third-generation (3G) communication protocols, fourth-generation (4G) communication protocols, 4.5G communication protocols, fifth-generation (5G) communication protocols, 5.5G communication protocols, 5G-Advanced Networks, or sixth-generation (6G) networks.

[0042] In some implementations, the communication environment 100 can be implemented in an NTN. The NTN can have different payload types. Figure 2A and Figure 2B A schematic diagram illustrating NTN scenarios with different payload types is provided. Figure 2AThe NTN is based on a transparent payload, and Figure 2B The NTN is based on regenerated payload.

[0043] In some example implementations, the satellite or UAS platform can implement transparent or regenerated (with on-board processing) payloads. The satellite or UAS platform can generate beams (e.g., typically several beams) over a given service area defined by its field of view 260. The coverage area 250 of the beams is typically elliptical. The field of view of the satellite or UAS platform depends on the on-board antenna pattern and minimum elevation angle.

[0044] like Figure 2A As shown, in the transparent payload scenario, UE 210 can communicate with satellite 220 or the UAS platform via a serving link, and satellite 220 or the UAS platform can communicate with gateway 230 connected to data network 240 via a feeder link. In this case, satellite 220 or the UAS platform can perform RF filtering, frequency conversion, and amplification, so the waveform signal repeated by the payload may remain unchanged. Based on the transparent payload, UE 210 can connect to data network 240. The round-trip time (RTT) in this case reflects the time it takes for data to be transmitted from UE 210 to gNB (located on the ground) via satellite 220 or the UAS platform.

[0045] like Figure 2B As shown, in the regenerated payload scenario, UE 210 can communicate with satellite 220-1 or the UAS platform via a serving link. Satellite 220-1 or the UAS platform can communicate with satellite 220-2 or the UAS platform via an inter-switch link (ISL), and satellite 220-2 or the UAS platform can communicate with gateway 230 connected to data network 240 via a feeder link. If the ISL is unavailable, satellite 220 or the UAS platform can communicate with gateway 230 connected to data network 240 via a feeder link. In this case, satellites 220-1 and 220-2 (or the UAS platform) can perform RF filtering, frequency conversion and amplification, demodulation / decoding, handover and / or routing, and encoding / modulation, which is essentially equivalent to all or part of the functions of a base station (e.g., gNB) on both the satellite and the UAS platform. Based on the regenerated payload, UE 210 can connect to data network 240. The RTT in this case reflects the time it takes for data to be transmitted from UE 210 to the gNB (located on the satellite or UAS platform).

[0046] In NTN, handover from a source cell to a target cell can include intra-satellite handover or inter-satellite handover. Figures 3A to 3D Schematic diagrams illustrating intra-satellite and inter-satellite handover according to some embodiments of this disclosure are provided. For example... Figure 3AAs shown, satellite communication systems support two cells associated with the same gateway or base station. In this case, if a terminal device performs a handover between two cells, the handover occurs on the same feeder link, meaning it is performed through the same gateway or base station. Figure 3A The handover shown can also be referred to as an intra-satellite handover with the same feeder link.

[0047] like Figure 3B As shown, a satellite communication system supports two cells associated with different gateways or base stations. In this case, if a terminal device performs a handover between two cells, the handover occurs on different feeder links, meaning the handover is performed through different gateways or base stations. Figure 3B The handover shown can also be referred to as an intra-satellite handover with different feeder links.

[0048] like Figure 3C As shown, a satellite communication system supports a first cell provided by a gateway or base station, and a second cell provided by another gateway or base station. In this scenario, if a terminal device performs a handover between the two cells, the handover is performed via different satellites and different gateways or base stations. Figure 3C The handover shown can also be referred to as an inter-satellite handover with gateway / base station switching.

[0049] like Figure 3D As shown, the satellite communication system supports a first cell provided by a gateway or base station, and a second cell provided by the same gateway or base station. In this case, if the terminal equipment performs a handover between the two cells, the handover is performed through different satellites but with the same gateway or base station. Figure 3D The handover shown can also be referred to as an inter-satellite handover with the same gateway / base station.

[0050] As discussed here, handover without a random access channel (RACH) is supported in release 18. In one solution, RACH-free handover in NR NTN is an L3 mobility procedure and uses the RACH-free handover procedure of LTE as a baseline. In RACH-free handover in NTN, the network indicates (implicitly or explicitly) whether the timing advance amount derived from the timing advance command (denoted as NTA) in the target cell is the same as that in the source cell or is explicitly provided by the network. Dynamic grants (DGs) from the target cell for RACH-free PUSCH transmission are supported to reduce random access congestion in the target cell.

[0051] In Rel-18, the target is not RACH-free HO for NTN-TN mobility. For the initial UL transmission in a RACH-free HO, pre-assigned authorization is supported in the RACH-free HO command. In some cases, NTN RACH-free HO is supported for intra-satellite handover with the same feeder link (i.e., with the same gateway / gNB). In some other cases, NTN RACH-free HO can be supported for intra-satellite handover with different feeder links (i.e., with gateway / gNB switching), inter-satellite handover with gateway / gNB switching, and inter-satellite handover with the same gateway / gNB.

[0052] In one solution, the general UE procedure for confirming NTN no-RACH HO may include the following steps: (1) receiving a no-RACH HO command, which may optionally include a pre-assigned grant (for L3 no-RACH HO at the RRC layer; and for L1 / L2 no-RACH HO at the MAC layer); (2) starting a timer T304 for the target cell (e.g., at the RRC layer); (3) performing DL and UL synchronization and starting a timer T430 (e.g., at the RRC layer and MAC layer); (4) starting a time alignment timer (e.g., at the MAC layer); (5) if the pre-assigned grant is not configured in the no-RACH HO command, monitoring the target cell's physical downlink control channel (PDCCH) to obtain dynamic grant, e.g., at the MAC layer and physical (PHY) layer; (6) sending a UE with available UL grants including RRCReconfigurationComplete (7) Initial UL transmission of the message (e.g., at the RRC layer, MAC layer, PHY layer); (8) upon receiving the NW acknowledgment, consider that no RACH HO has been completed (e.g., at the RRC layer, MAC layer); and (9) stop the timer T304 for the target cell (e.g., at the RRC layer).

[0053] Furthermore, pre-allocated grants can be provided as Type 1 CG. At least for pre-allocated grants, for confirmation without RACHHO completion, the LTE method can be reused, i.e., using UE contention to resolve the identifier MAC CE, but the UE ignores the content of this field. It is possible to support the combination of no-RACHHO with time-based conditional handover (CHO) for NTN, and further consider the following: (1) the effectiveness of pre-allocated grants and the potential waste of reserved resources; and (2) when / how to provide dynamic grants in PDCCH.

[0054] In the proposed solution, during NTN RACH-free handover, the network indicates that the NTA in the target cell is the same as that in the source cell, or indicates that the NTA explicitly provided by the NW is 0. In some cases, synchronization between the source and target cells may not be an issue in NTN RACH-free HO. After the RACH-free HO is completed, the pre-allocated UL grant is released. The LTE method (confirming HO completion) is reused for both pre-allocated and dynamic grants. In some cases, it is assumed that the UL synchronization process in the target cell is the same in both RACH-based and RACH-free HO, except for how the NTA is obtained.

[0055] In another proposed solution, a single beam can be instructed in the HO command to monitor the target cell PDCCH to obtain dynamic grants for the initial UL transmission. The pre-allocated grant is associated with an SSB. The mapping between Type 1 CG and SSB in the configured grant-small data transmission (CG-SDT) can be the baseline for how the pre-allocated grant is configured to be mapped to the SSB. The UE selects an SSB associated with a pre-allocated grant having a reference signal received power (RSRP) above a configured threshold and uses the selected SSB and the corresponding UL grant timing for the initial UL transmission. The TA report can be included in the information element (IE) ServingCellConfigCommon in the RACH-free HO command. It should be understood that if the pre-allocated grant is not configured and dynamic grants are used for the first UL transmission, HARQ mode A is recommended for the HARQ procedure if the UL Hybrid Automatic Repeat reQuest (HARQ) mode is configured (in any case, this depends on the specific network implementation). The MAC entity applies an NTA (value 0 or the same as the source cell), which is configured in a no-RACH HO command for the Primary Timing Advance Group (PTAG). If no SSB mapped to a pre-assigned license has an RSRP higher than the threshold, it can fall back to RACH HO (with a new SSB selection) while timer T304 is running.

[0056] In another proposed solution, the UE relies on timer T304 and the RRC re-establishment procedure to resolve RACH-less HO failures in Rel-18 NTN (as in LTE). No new NTN-specific enhancements are introduced. If the TAT expires, the UE follows the legacy procedure regardless of the RACH-less HO configuration. It should be understood that the NW can ensure the proper configuration of the TAT and T304 values ​​(depending on the specific NW implementation, this does not need to be reflected in the specification). Furthermore, for RACH-less L1 / L2-triggered Mobility (LTM), for RACH-less NTN, the UE determines the successful reception of its first UL data based on the PDCCH received in the target cell, which addresses the UE's Cell-Radio Network Temporary Identifier (C-RNTI) and schedules a new transmission as the first UL transmission. DL allocation or UL authorization can be addressed to the same HARQ procedure used for the "new transmission". It should also be understood that this does not preclude the possibility of using contention to resolve MACCE, but this will not be used as a determination of completion without RACH HO. Alternatively, when the UE starts a PTAG time alignment timer in NTN without RACH HO, the LTE baseline may be followed.

[0057] For both configuration-based and dynamic authorization, Rel-18 NTN supports a combination of non-RACH HO and time-based CHO. For dynamic authorization, this should only be configured by the network (depending on the specific network implementation) if there is no risk of confusion regarding which beam to use.

[0058] In some solutions, for the dynamic grant monitoring target cell PDCCH used for initial UL transmission, there is no situation where multiple beams are indicated for no-RACH handover. In this case, the UE does not expect multiple beams to be indicated from the network. For path loss measurement in the case of dynamic scheduling initial PUSCH used for no-RACH handover, the UE uses a reference signal (RS) resource to calculate the path loss estimate, which comes from an SS / PBCH block with the same index as the SS / PBCH block index used by the UE to monitor and schedule the dynamic UL grant for initial transmission.

[0059] In some other solutions, for initial UL transmissions scheduled by dynamic grant in RACH-less handover, the principles of power control for Msg3 (or MsgA) PUSCH are followed, except for path loss determination. For path loss determination, the UE uses RS resources derived from SS / PBCH blocks with the same index as the SS / PBCH block index used by the UE to monitor and schedule the PDCCH for the initial transmission of dynamic UL grants.

[0060] In addition, the following aspects can support work on RACH-free handover: Pre-assigned mandates can be associated with SSBs. The mapping between Type 1 CGs and SSBs in the CG-SDT can be a baseline for how pre-assigned mandates are configured to be mapped to SSBs.

[0061] Regardless of the solutions described above, the reciprocity between UL and DL is imperfect, due to factors such as UL and DL operating in different frequency bands, RX and TX using different phase array antenna panels (e.g., Starlink), and variations in UL and DL power differences due to gateway switching (e.g., transparent satellites: amplifiers and filters). Specifically, due to imperfect hardware and calibration, the array gain between RX and TX will vary with the scan angle. An amplifier may be saturated by a high-power gateway but have limited amplification for a low-power gateway. The measured DL power may be the same, but the required UL power may differ.

[0062] Given the above, several issues arise. For example, for intra-satellite / inter-satellite handover with / without feeder link switching, power control cannot be directly inherited, and UL power control cannot depend on DL measurements or be inherited from the source cell. Furthermore, for RACH-less HO, initial PUSCH transmit power control cannot depend on the PRACH preamble power and preamble power ramp. Additionally, without proper power control, RACH-less HO cannot save latency during the HO period and can fall back to RRC for re-establishment.

[0063] In view of the above problems, the example embodiments of this disclosure propose a solution for power control for handover. In one solution, the terminal device can adjust the transmit power for the target cell based on the remaining time associated with the determination of the result of handover from the source cell to the target cell. The terminal device can further use the adjusted transmit power to send a handover indication message to the target cell. In this way, an appropriate power ramp rate can be used for RACH-free HO.

[0064] In another solution, the terminal device can receive information from the source cell regarding the adjustment status of power control for the target cell. Based on this information, the terminal device can determine the transmit power for the target cell. Furthermore, the terminal device can use this transmit power to send a message to the target cell instructing a handover from the source cell to the target cell. In this way, an appropriate power control adjustment status can be determined for RACH-free HO.

[0065] In another solution, the terminal device can receive information from the source cell about a scaling factor for the target cell, which will be applied to the path loss estimate for the target cell. The terminal device can then determine the transmission power for the target cell based on this information and the path loss estimate. Furthermore, the terminal device can use this transmission power to send a message to the target cell indicating a handover from the source cell. This allows for the determination of the appropriate contribution of the path loss estimate to the transmission power.

[0066] By employing one or more of the solutions described above, an appropriate transmit power can be determined for RACH-free HO (e.g., NTN RACH-free HO). Therefore, the success rate of RACH-free HO can be improved.

[0067] Example embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. To better understand the embodiments of this disclosure, an example of transmit power calculation will first be described.

[0068] If the UE transmits PUSCH on the active UL bandwidth portion (BWP) b of carrier f in serving cell c using a parameter set configuration with index j and a PUSCH power control adjustment state with index l, then the UE will transmit PUSCH at PUSCH transmission timing i. Determined as: (1) Where parameters It is the maximum output power configured by the UE based on the power level of the carrier f of the serving cell c in the PUSCH transmission timing i. It is used to serve the community carrier UL BWP activities PUSCH sending timing parameters ， And it can be determined by following the Msg3 / MsgA procedure. To serve the community carrier UL BWP activities PUSCH sending timing The number of resource blocks represents the bandwidth allocated to PUSCH resources. Parameter It is used by the UE for serving the cell carrier Reference signal index for the DL BWP activity The calculated downlink path loss estimate is in dB. Parameters It is used in serving cells carrier ULBWP activities parameters coefficient 。 With each carrier Service Community Each UL BWP This relates to the modulation and coding scheme (MCS). Parameters It is used for PUSCH sending timing Central Service Community carrier UL BWP activities The power control adjustment status.

[0069] Some implementation schemes for power control for HO are now described in detail. In some implementation schemes, if the terminal device does not receive a handover confirmation from the target cell, the terminal device may gradually adjust (e.g., ramp up) the transmit power used for UL transmission to the target cell.

[0070] refer to Figure 4 This illustrates an example signaling flow 400 for power control for handover according to some embodiments of this disclosure. For discussion purposes, reference will be made to... Figure 1 The signaling flow 400 is discussed using terminal device 110, source cell 120, and target cell 130 as examples.

[0071] like Figure 4 As shown, in some embodiments, source cell 120 may send (410) a command to terminal device 110 to hand over from source cell 120 to target cell 110, which may also be referred to as a handover command. Accordingly, terminal device 110 may receive (420) the handover command and perform the handover process. In some embodiments, the handover command may be a RACH-free handover command that may include pre-assigned authorization. However, it should be noted that in some alternative embodiments, terminal device 110 may perform the handover process from source cell 120 to target cell 130 without a handover command (e.g., in the case of a CHO).

[0072] Alternatively or otherwise, in some implementations, source cell 120 may transmit (430) an indication of duration. Terminal device 110 may receive (440) an indication of duration. The duration is associated with an adjustment of the transmit power for transmission to target cell 130. For L1 / L2 mobility, this can be achieved through RRC signaling (e.g., LTM-Config The duration indication can be sent in the message or MAC CE. For L3 mobility, it can be sent in RRC signaling (e.g., CellGroupConfig information / PUSCH- PowerControl The message contains an indication of the duration of transmission. The duration can vary depending on the circumstances. A detailed description is provided below with reference to an example implementation.

[0073] During the handover process, terminal device 110 may send a message to target cell 120 indicating handover to target cell 130. For example, the message may be an RRC reconfiguration complete message. If terminal device 110 does not receive a response (e.g., acknowledgment) from target cell 130 within a certain period of time (e.g., before timer T304 expires), terminal device 110 may retransmit the message.

[0074] In this scenario, terminal device 110 may adjust (450) the transmission power for target cell 130 based on the remaining time associated with the determination of the result of the handover from source cell 120 to target cell 130. Terminal device 110 may then use the adjusted transmission power to send (460) a message to target cell 130. Target cell 130 may receive (470) a message from terminal device 110 indicating a handover from source cell 120 to target cell 130.

[0075] The remaining time can be correlated with a period of time during which terminal device 110 monitors responses from target cell 130. In some embodiments, upon receiving a handover command, terminal device 120 may start a first timer for handover, such as timer T304 described above. In such embodiments, the remaining time can be correlated with the effective length of the first timer. The determination of the remaining time will be described in detail below.

[0076] The remaining time can be used to adjust any parameter used to calculate the transmission power, such as any parameter described in formula (1). In this way, the terminal device can adaptively adjust the transmission power based on the remaining time available for adjusting the transmission power.

[0077] In some implementations, terminal device 110 may determine the adjustment state of power control for target cell 130 based on the remaining time and the round-trip time for target cell 130. Terminal device 110 may adjust the transmit power based on the adjustment state. For example, the remaining number of times terminal device 110 can adjust the transmit power may be determined based on the remaining time and RTT. Therefore, the adjustment state may be determined based on the remaining number of times for transmit power adjustment.

[0078] The adjustment state can be determined based on the remaining time in any suitable manner. For example, it can be determined based on a function of the remaining time.

[0079] In some implementations, the adjustment state can be determined based on the following: remaining time, RTT, the maximum transmit power supported by terminal device 110, and another transmit power previously used to transmit messages. The maximum transmit power may represent the upper limit of transmit power achievable by terminal device 110. The other transmit power may be the previous transmit power used in a previous transmission instance. In such implementations, the adjustment state can be determined such that the maximum transmit power can be reached before the end of a period used to monitor responses from target cell 130. For example, terminal device 110 may ramp up the PUSCH transmit power from the current state to the maximum output power before timer T304 expires.

[0080] Adjust the PUSCH power control state according to formula (1). As an example, The calculation can be performed as follows: = (2) (3) in, Indicates the timing of transmission The power control adjustment status; Indicates the timing of previous transmission The power control adjustment state, for example... =1; index With index They can be the same or different; This indicates the maximum transmit power configured for the UE; Indicates the timing of previous transmission The transmission power used. This indicates the remaining time described above, and A function representing the remaining time.

[0081] In some implementations, the remaining time can also be a function of the target cell's RTT. For example, it can be calculated as follows: (3') in, This represents the RTT of target cell 130. Formula (3') can be considered as an example of formula (3).

[0082] By using the floor operator " "Applied to" This ensures that maximum transmission power can be reached in the shortest possible time. However, it should be noted that the floor function "" in formula (3) can be used to achieve this. This is an example, not a limitation. (Regarding "") "It is possible to apply any other operator or not to apply any operator. For example, it could be a rounding operator or a floor operator that is advantageous for the specific implementation complexity."

[0083] In this example, terminal device 110 can calculate the power ramp step size based on the remaining time (before timer T304 expires) and the RTT of target cell 130. Then, terminal device 110 can transmit PUSCH using the calculated power as described in formula (1).

[0084] Some example implementations for determining the remaining time are now described. In some implementations, terminal device 110 may determine the remaining time based on a first time length for power adjustment and a second time length elapsed since source cell 120 received the handover command. For example, the first time length may indicate the period during which terminal device 110 ramps up the PUSCH power.

[0085] In some implementations, the first time length may be predefined. In some implementations, the first time length may be configured by the network device. For example, terminal device 110 may receive an indication of the first time length from source cell 120.

[0086] In some implementations, the network may configure a second timer with a first time length for terminal device 110. In such implementations, upon receiving a handover command, terminal device 110 may start a first timer (e.g., timer T304) for handover to target cell 130 and a second timer with a first time length for transmit power adjustment.

[0087] In some implementations, the first time length may be shorter than the effective time length of the first timer. For example, the second timer may expire before the first timer.

[0088] As an example, source cell 120 can use a timer Configure terminal device 110 to timer Before the timeout, ramp up the PUSCH transmit power from the current state to the maximum output power. (Timer) It can be started together with timer T304, for example, upon receiving a handover command. In this example, the remaining time in formula (3) can be calculated as follows: (4) in, Indicates timer Effective time length ， and It is a timer The duration after startup (e.g., in milliseconds).

[0089] Terminal device 110 can use formulas (1), (2), (3) and (4) to calculate the transmission power. Then, terminal device 110 can use the calculated power to transmit PUSCH.

[0090] In this example, for L1 / L2 mobility, it can be done in RRC signaling (e.g., LTM-Config (Message) or MAC CE send (430) timer The duration of the time. For L3 mobility, this can be achieved through RRC signaling (e.g., CellGroupConfig information / PUSCH-PowerControl Send (430) timer in message) The length of time.

[0091] In some implementations, the remaining time can be determined using the relative time of the first timer used for handover. For example, terminal device 110 may determine the remaining time based on the following: the effective duration of the first timer used for handover to target cell 130, the time difference between the expiration of the first timer and the termination of the transmit power adjustment, and the second duration of time elapsed since the source cell 120 received the command for handover.

[0092] In some implementations, the time difference can be predefined. In some implementations, the network can configure the time difference to terminal device 110. For example, terminal device 110 can receive an indication of the time difference (440) from source cell 120.

[0093] In some implementations, the time difference may represent the difference in effective time length between a first timer used for handover and a second timer used for transmit power adjustment. For example, the time difference may represent timer T304 and timer T405. The difference in the effective time length between them. In such implementations, for example, upon receiving a handover command, the first and second timers can be started together.

[0094] As an example, source cell 120 can configure a relative timer for timer T304 to terminal device 110 to ramp up the PUSCH transmit power from the current state to the maximum output power before the timer expires. The relative timer can start together with timer T304, but can start earlier than timer T304. maturity.

[0095] In this example, the remaining time in formula (3) can be calculated as follows: (5) in, This indicates the effective duration of timer T304. This represents the difference between the effective duration of timer T304 and the relative timer, and For timer The duration after startup (e.g., in milliseconds).

[0096] Terminal device 110 can use formulas (1), (2), (3) and (5) to calculate the transmission power. Then, terminal device 110 can use the calculated power to transmit PUSCH.

[0097] In this example, for L1 / L2 mobility, it can be done in RRC signaling (e.g., LTM-Config Send in message or MAC CE The value. For L3 mobility, it can be set in RRC signaling (e.g., CellGroupConfig information / PUSCH- PowerControl Send in message The value of .

[0098] Alternatively, in some implementations, the remaining time can be determined relative to the decoding of the uplink grant from target cell 130. For example, terminal device 110 can determine the remaining time based on a third time length for transmit power adjustment and a fourth time length elapsed since the grant was decoded from target cell 130. For example, if the handover command does not contain a CG, terminal device 120 can monitor the PDCCH from target cell 130 to obtain the DG. Therefore, the remaining time can be determined in association with the decoding of the DG.

[0099] In some implementations, the third time length may be predefined. In some implementations, the third time length may be configured by the network device. For example, terminal device 110 may receive (440) an indication of the third time length from source cell 120.

[0100] In some implementations, the network may configure terminal device 110 with a third timer of a third duration for transmit power adjustment. In such implementations, terminal device 110 may initiate the third timer of the third duration for transmit power adjustment when decoding an authorization from target cell 130.

[0101] As an example, source cell 120 can use timer T' ramp-up The terminal device 110 is configured to ramp up the PUSCH transmission power from the current state to the maximum output power before the timer expires. The target cell 130 can schedule PUSCH transmission via DG. Timer T' can be started after decoding the DG from the target cell 130. ramp-up .

[0102] In this example, the remaining time in formula (3) can be calculated as follows: (6) in, Indicates timer T' ramp-up The effective duration, and It is the length of time since the target cell decoded the DG (e.g., in ms).

[0103] Terminal device 110 can use formulas (1), (2), (3) and (6) to calculate the transmission power. Then, terminal device 110 can use the calculated power to transmit PUSCH.

[0104] In this example, for L1 / L2 mobility, it can be done in RRC signaling (e.g., LTM-Config (Message) or MAC CE send timer T' ramp-up The effective duration. For L3 mobility, this can be achieved through RRC signaling (e.g., CellGroupConfig information / PUSCH-PowerControl Send timer T' in the message ramp-up The effective duration.

[0105] The implementation described above allows source cell 120 to instruct terminal device 110 to ramp up the PUSCH transmit power from the current state to the maximum output power before the timer expires. This allows terminal device 110 to automatically adjust the power ramp rate and ensure transmit power, thus facilitating successful handover.

[0106] To better understand the implementation scheme for transmit power adjustment, the example UE procedure for NTN without RACH HO may include the following steps: - Receive RACH HO commands that may optionally include pre-assigned authorization; -Start timer T304 for the target cell; -Optionally, start timer T ramp-up ; - Perform DL and UL synchronization, and start timer T430; - Start-up time alignment timer; - If the pre-allocated authorization is not configured in the no-RACH HO command, monitor the target cell PDCCH to obtain dynamic authorization; -Optionally, start timer T' ramp-up ; -Use available UL-authorized delivery including RRCReconfigurationComplete Initial UL transmission of the message; -If timer T ramp-up or T' ramp-up If it is running, the PUSCH transmission power ramp will increase, and if no acknowledgment is received from the target cell, then the following actions will be performed: RRCReconfigurationComplete Resend the message; - Upon receiving NW confirmation, it is assumed that no RACH HO has been completed; and - Stop timer T304 used for the target cell.

[0107] In the above UE process, timer T can be determined in any suitable manner. ramp-up The effective duration. In the example, timer T... ramp-up The effective time length can be predefined or indicated by the network, for example, as relative to the first time length described above. Another example is timer T. ramp-up The effective time length can be determined based on the difference between the effective time length of timer T304 and the network time length. This difference can be predefined by the network or indicated, such as relative to the time difference described above. It should be noted that the above example procedure is given as an example and is not intended to be a limitation.

[0108] The embodiments disclosed herein also propose other solutions for power control. The following, in conjunction with… Figure 5 and Figure 6 Provide a detailed description.

[0109] In some implementations, in a RACH-free HO, the adjustment state for power control can be configured by the source cell. Figure 5 Signaling flow 500 for handover power control according to some embodiments of this disclosure is illustrated. Reference will be made to this document for discussion purposes. Figure 1 The signaling flow 500 is discussed, for example, by using terminal device 110, source cell 120 and target cell 130 as examples.

[0110] Source cell 120 may send (510) information about the adjustment status of power control for target cell 130 to terminal device 110. Accordingly, terminal device 110 may receive (520) information about the adjustment status of power control.

[0111] Terminal device 110 (530) may determine the transmit power for target cell 130 based on this information. In some embodiments, the information may indicate a value for the adjustment state, and the transmit power may be determined based on the indicated value. In some embodiments, the information may indicate a difference between the adjustment state and another adjustment state for power control of source cell 120. The transmit power may be determined based on this difference and the other adjustment state. In some embodiments, the information may indicate an identifier (e.g., an index) of the adjustment state for power control of the target cell.

[0112] In some implementations, this information may be received in a command used for the handover. For example, source cell 120 sends a handover command to terminal device 110 that includes information about adjusting the status.

[0113] Continue to refer to Figure 5 Terminal device 110 may send (540) a message indicating handover to target cell 130, such as an RRC reconfiguration complete message. Target cell 130 may receive (550) this message. Alternatively, target cell 130 may also send an acknowledgment to terminal device 110. This acknowledgment may indicate successful handover.

[0114] For example, source cell 120 can configure the PUSCH power control adjustment status in the handover command. The absolute value. In this case, the terminal device 110 can calculate the power adjustment state value in formula (1) as follows. : = (7) in, This indicates the value of the PUSCH power control adjustment status indicated by the source cell, and This represents the value of the PUSCH power control adjustment state to be used in formula (1).

[0115] Therefore, the transmission power can be calculated. Then, the terminal device 110 can transmit the PUSCH using the calculated power as described in formula (1).

[0116] As another example, source cell 120 can be configured with relative values. Power adjustment status used in handover commands.

[0117] In this case, the terminal device 110 can calculate the power adjustment state value in formula (1) as follows. : = (8) in, This value represents the PUSCH power control adjustment status used in the source cell. This represents the relative value indicated by the source cell, and This represents the value of the PUSCH power control adjustment state to be used in formula (1).

[0118] Therefore, the transmission power can be calculated. Then, the terminal device 110 can transmit the PUSCH using the calculated power as described in formula (1).

[0119] As yet another example, source cell 120 can be configured with an index. PUSCH power control adjustment status in the handover command In this case, the terminal device 110 can calculate the power adjustment state value in formula (1) as follows. : = (9) in, An index indicating the PUSCH power control adjustment status indicated by the source cell. Indicates index-based The calculated value of the PUSCH power control adjustment state, and This represents the value of the PUSCH power control adjustment state to be used in formula (1).

[0120] Therefore, the transmission power can be calculated. Then, the terminal device 110 can transmit the PUSCH using the calculated power as described in formula (1).

[0121] In these examples, for L1 / L2 mobility, it can be done in RRC signaling (e.g., LTM-Config Send in message or MAC CE The instruction. For L3 mobility, it can be indicated in RRC signaling (e.g., CellGroupConfig information / PUSCH-PowerControl Send in message Instructions.

[0122] In this way, source cell 120 can determine the power adjustment status based on UE measurements and reports from target cell 130. Then, source cell 120 can indicate the absolute / relative power adjustment status value in the handover command for target cell 130. Therefore, terminal device 110 can determine the accurate power adjustment status with a high success rate and reduce handover latency.

[0123] In some implementations, in RACH-free HO, the scaling factor applied to path loss estimation can be configured by the source cell. Figure 6 Signaling flow 600 for handover power control according to some embodiments of this disclosure is illustrated in another example. Reference will be made to this document for discussion purposes. Figure 1 The signaling flow 600 is discussed, for example, by using terminal device 110, source cell 120 and target cell 130.

[0124] Source cell 120 may send (610) information to terminal device 110 regarding a scaling factor for target cell 130, which will be applied to the path loss estimate of target cell 130. Correspondingly, terminal device 110 may receive (620) information regarding the scaling factor. For example, the scaling factor may be a parameter in formula (1). .

[0125] Terminal device 110 (630) can determine the transmission power for target cell 130 based on this information and path loss estimation.

[0126] In some implementations, this information may indicate the value of the scaling factor, and the transmit power may be determined based on the indicated value and the path loss estimate.

[0127] In some implementations, this information may indicate the ratio of the scaling factor to another scaling factor associated with the random access procedure, and the transmit power may be determined based on the indicated ratio, the other scaling factor, and the path loss estimate. For example, the other scaling factor may have a value determined for MsgA or Msg3.

[0128] In some implementations, this information may be received in a command used for the handover. For example, source cell 120 sends a handover command to terminal device 110 that includes information about adjusting the status.

[0129] Continue to refer to Figure 6 Terminal device 110 can use this transmit power to transmit (640) a message indicating a handover from source cell 120 to target cell 130. Target cell 130 can receive (650) this message. In some embodiments, target cell 130 can send an acknowledgment to terminal device 110. This acknowledgment can indicate a successful handover.

[0130] In this way, source cell 120 can determine the scaling factor. Then, source cell 120 can indicate the absolute / relative scaling factor to be applied to the path loss estimate in the handover command for target cell 130. Therefore, terminal device 110 can determine the accurate scaling factor with a high success rate and reduce handover delay.

[0131] Example methods, devices, and specific implementations Figure 7A A flowchart illustrating a communication method 700A implemented at a terminal device according to some embodiments of the present disclosure is shown. For discussion purposes, [the following will be discussed]. Figure 1 Method 700A is described from the perspective of terminal device 110.

[0132] At box 710, terminal device 110 adjusts the transmission power for the target cell based on the remaining time associated with the determination of the result of the handover from the source cell to the target cell.

[0133] At frame 720, terminal device 110 uses the adjusted transmit power to send a message indicating the handover to the target cell.

[0134] In some example implementations, terminal device 110 determines an adjustment state for power control of the target cell based on the remaining time and the round-trip time for the target cell; and adjusts the transmit power based on the adjustment state.

[0135] In some example implementations, the adjustment state is determined based on the following: the remaining time, the round-trip time, the maximum transmission power supported by the terminal device, and another transmission power previously used to send the message.

[0136] In some example implementations, terminal device 110 determines the remaining time based on a first time length for power adjustment and a second time length elapsed since the source cell received the command for the handover.

[0137] In some example implementations, when the terminal device 110 receives the command, it starts a first timer for the handover to the target cell and a second timer with the first time length for the transmit power adjustment.

[0138] In some example implementations, terminal device 110 receives an indication of the first time length from the source cell.

[0139] In some example implementations, the first time length is shorter than the effective time length of the first timer used for the handover to the target cell.

[0140] In some example implementations, terminal device 110 determines the remaining time based on the following: the effective time length of a first timer used for the handover to the target cell, the time difference between the expiration of the first timer and the termination of the transmit power adjustment, and the second time length elapsed since the source cell received the command for the handover.

[0141] In some example implementations, terminal device 110 receives an indication of the time difference from the source cell.

[0142] In some example implementations, terminal device 110 determines the remaining time based on a third time length for power adjustment and a fourth time length that has elapsed since the target cell was authorized to decode.

[0143] In some example implementations, when decoding the authorization, terminal device 110 starts a third timer with the third time length for the transmission power adjustment.

[0144] In some example implementations, terminal device 110 receives an indication of the third time length from the source cell.

[0145] Figure 7B A flowchart illustrating a communication method 700B implemented at a network device according to some embodiments of this disclosure is shown. For discussion purposes, [the following will be discussed]. Figure 1 Method 700B describes the approach from the perspective of the network devices in the target cell 130.

[0146] At box 730, the network device receives a message from the terminal device indicating a handover from the source cell to the target cell. The message is transmitted using a transmit power adjusted based on the remaining time associated with the determination of the handover result.

[0147] Figure 7C A flowchart illustrating a communication method 700C implemented at a network device according to some embodiments of this disclosure is shown. For discussion purposes, [the following will be discussed]. Figure 1 Method 700C describes the method from the perspective of the network devices in the source cell 120.

[0148] At box 740, the network device sends an indication of the duration of time to the terminal device, which is associated with a transmission power adjustment used to send a message indicating handover from the source cell to the target cell.

[0149] In some example implementations, the time length includes at least one of the following: a first time length for transmitting power adjustment and initiated upon receiving a command for the handover from the source cell, the time difference between the expiration of a first timer for the handover to the target cell and the termination of the transmitting power adjustment, or a third time length for transmitting power adjustment and initiated upon decoding authorization from the target cell.

[0150] Figure 8A A flowchart illustrating a communication method 800A implemented at a terminal device according to some embodiments of the present disclosure is shown. For discussion purposes, [the following will be discussed]. Figure 1 Method 800A is described from the perspective of the terminal device 110 in the middle.

[0151] At box 810, terminal device 110 receives information from the source cell about the adjustment status of power control for the target cell.

[0152] At box 820, terminal device 110 determines the transmission power for the target cell based on this information.

[0153] At frame 830, terminal device 110 uses the transmit power to send a message to the target cell indicating a handover from the source cell to the target cell.

[0154] In some example implementations, the information indicates the value of the adjustment state, and the transmission power is determined based on the indicated value.

[0155] In some example implementations, the information indicates the difference between the adjustment state and another adjustment state for power control of the source cell, and the transmit power is determined based on the difference and the other adjustment state.

[0156] In some example implementations, this information is received in the command used for the handover.

[0157] Figure 8B A flowchart illustrating a communication method 800B implemented at a network device according to some embodiments of this disclosure is shown. For discussion purposes, [the following will be discussed]. Figure 1 Method 800B describes the method from the perspective of the network devices in the source cell 120.

[0158] At box 840, the network device sends information to the terminal device regarding the adjustment status of power control for the target cell. The terminal device will then perform a handover from the source cell to the target cell.

[0159] In some example implementations, this information indicates the value of the adjustment state.

[0160] In some example implementations, this information indicates the difference between the adjustment state and another adjustment state used for power control of the source cell.

[0161] In some example implementations, this information is sent in the command used for the handover.

[0162] Figure 8C A flowchart illustrating a communication method 800C implemented at a network device according to some embodiments of this disclosure is shown. For discussion purposes, [the following will be discussed]. Figure 1 Method 800C describes the approach from the perspective of the network devices in the target cell 130.

[0163] At box 850, the network device receives a message from the terminal device indicating a handover from the source cell to the target cell. The message is transmitted using a transmit power determined based on information from the source cell regarding the adjustment status of power control for the target cell.

[0164] Figure 9A A flowchart illustrating a communication method 900A implemented at a terminal device according to some embodiments of the present disclosure is shown. For discussion purposes, [the following will be discussed]. Figure 1 Method 900A is described from the perspective of terminal device 110.

[0165] At box 910, terminal device 110 receives information from source cell about scaling factors for target cell, which will be applied to path loss estimation for target cell.

[0166] At box 920, terminal device 110 determines the transmission power for the target cell based on this information and the path loss estimate.

[0167] At frame 930, terminal device 110 uses the transmit power to send a message to the target cell indicating a handover from the source cell to the target cell.

[0168] In some example implementations, this information indicates the value of the scaling factor, and the transmit power is determined based on the indicated value and the path loss estimate.

[0169] In some example implementations, the information indicates the ratio of the scaling factor to another scaling factor associated with the random access procedure, and the transmit power is determined based on the indicated ratio, the other scaling factor, and the path loss estimate.

[0170] Figure 9B A flowchart illustrating a communication method 900B implemented at a network device according to some embodiments of this disclosure is shown. For discussion purposes, [the following will be discussed]. Figure 1 Method 900B describes the method from the perspective of the network devices in the source cell 120.

[0171] At box 940, the network device sends information to the terminal device about a scaling factor for the target cell, which will be applied to the path loss estimate of the target cell, whereby the terminal device will perform a handover from the source cell to the target cell.

[0172] In some example implementations, this information indicates the value of the scaling factor.

[0173] In some example implementations, this information indicates the ratio of the scaling factor to another scaling factor associated with the random access procedure.

[0174] Figure 9C A flowchart illustrating a communication method 900C implemented at a network device according to some embodiments of this disclosure is shown. For discussion purposes, [the following will be discussed]. Figure 1 Method 900C describes the approach from the perspective of the network devices in the target cell 130.

[0175] At box 950, the network device receives a message from the terminal device indicating a handover from the source cell to the target cell. The message is transmitted using a transmit power determined based on information from the source cell regarding a scaling factor for the target cell, which will be applied to the path loss estimate for the target cell.

[0176] Figure 10 This is a simplified block diagram of a device 1000 suitable for implementing embodiments of the present disclosure. Device 1000 can be considered as follows: Figure 1 Another example implementation of any of the devices shown is provided. Therefore, device 1000 may be implemented at the terminal device 110 or network device 120 that provides source cell 120 and / or target cell 130, or as at least a part of that terminal device or network device.

[0177] As shown in the figure, device 1000 includes a processor 1010, a memory 1020 coupled to the processor 1010, a suitable transceiver 1040 coupled to the processor 1010, and a communication interface coupled to the transceiver 1040. The memory 1020 stores at least a portion of a program 1030. Depending on the requirements, the transceiver 1040 can be used for bidirectional or unidirectional communication. The transceiver 1040 may include at least one of a transmitter 1042 and a receiver 1044. The transmitter 1042 and receiver 1044 may be functional modules or physical entities. The transceiver 1040 has at least one antenna to facilitate communication; however, in practice, the access node mentioned in this application may have several antennas. The communication interface can represent any interface necessary for communication with other network elements, such as the X2 / Xn interface for bidirectional communication between eNBs / gNBs, the S1 / NG interface for communication between the Mobility Management Entity (MME) / Access and Mobility Management Function (AMF) / SGW / UPF and eNBs / gNBs, the Un interface for communication between eNBs / gNBs and relay nodes (RNs), or the Uu interface for communication between eNBs / gNBs and terminal equipment.

[0178] Assume that program 1030 includes program instructions that, when executed by the associated processor 1010, enable device 1000 to operate according to embodiments of this disclosure, as referenced herein. Figure 1 As discussed in Figure 9, the embodiments described herein can be implemented by computer software executable by the processor 1010 of device 1000, or by hardware, or by a combination of software and hardware. The processor 1010 can be configured to implement various embodiments of this disclosure. Furthermore, the combination of the processor 1010 and the memory 1020 can form a processing unit 1050 suitable for implementing various embodiments of this disclosure.

[0179] Memory 1020 can be of any type suitable for a local technology network and can be implemented using any suitable data storage technology, such as, as non-limiting examples, non-transitory computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Although only one memory 1020 is shown in device 1000, several physically different memory modules may exist in device 1000. Processor 1010 can be of any type suitable for a local technology network and may include one or more of the following: as non-limiting examples, general-purpose computers, special-purpose computers, microprocessors, digital signal processors (DSPs), and processors based on multi-core processor architectures. Device 1000 may have multiple processors, such as application-specific integrated circuit chips, which are time-dependent on a clock that synchronizes the main processor.

[0180] According to embodiments of this disclosure, a terminal device including circuitry is provided. The circuitry is configured to: adjust the transmit power for the target cell based on the remaining time associated with a determination of the result of a handover from a source cell to a target cell; and transmit a message indicating the handover to the target cell using the adjusted transmit power. According to embodiments of this disclosure, the circuitry can be configured to perform any method implemented by the terminal device as discussed above.

[0181] According to embodiments of this disclosure, a network device including circuitry is provided. The circuitry is configured to receive from a terminal device a message indicating a handover from a source cell to a target cell, and wherein the message is transmitted using a transmit power adjusted based on the remaining time associated with a determination of the result of the handover. According to embodiments of this disclosure, the circuitry can be configured to perform any of the methods implemented by the network device as discussed above.

[0182] According to embodiments of this disclosure, a network device including circuitry is provided. The circuitry is configured to send an indication of a duration to a terminal device, the duration being associated with a transmit power adjustment for sending a message indicating handover from a source cell to a target cell. According to embodiments of this disclosure, the circuitry can be configured to perform any of the methods implemented by the network device as discussed above.

[0183] According to embodiments of this disclosure, a terminal device including circuitry is provided. The circuitry is configured to: receive information from a source cell regarding an adjustment state for power control of a target cell; determine a transmission power for the target cell based on the information; and use the transmission power to send a message to the target cell indicating a handover from the source cell to the target cell. According to embodiments of this disclosure, the circuitry can be configured to perform any of the methods implemented by the terminal device as discussed above.

[0184] According to embodiments of this disclosure, a network device including circuitry is provided. The circuitry is configured to send information to a terminal device regarding an adjustment status for power control of a target cell, wherein the terminal device will perform a handover from the source cell to the target cell. According to embodiments of this disclosure, the circuitry can be configured to perform any of the methods implemented by the network device as discussed above.

[0185] According to embodiments of this disclosure, a network device including circuitry is provided. The circuitry is configured to receive from a terminal device a message indicating a handover from a source cell to a target cell, wherein the message is transmitted using a transmit power determined based on information from the source cell regarding an adjustment state for power control in the target cell. According to embodiments of this disclosure, the circuitry can be configured to perform any of the methods implemented by the network device as discussed above.

[0186] According to embodiments of this disclosure, a terminal device including circuitry is provided. The circuitry is configured to: receive from a source cell information about a scaling factor for a target cell, the scaling factor being applied to a path loss estimate for the target cell; determine a transmit power for the target cell based on the information and the path loss estimate; and use the transmit power to transmit a message to the target cell indicating a handover from the source cell to the target cell. According to embodiments of this disclosure, the circuitry can be configured to perform any of the methods discussed above implemented by the terminal device.

[0187] According to embodiments of this disclosure, a network device including circuitry is provided. The circuitry is configured to send information to a terminal device regarding a scaling factor for a target cell, which will be applied to a path loss estimate for the target cell, wherein the terminal device will perform a handover from the source cell to the target cell. According to embodiments of this disclosure, the circuitry can be configured to perform any of the methods implemented by the network device as discussed above.

[0188] According to embodiments of this disclosure, a network device including circuitry is provided. The circuitry is configured to receive from a terminal device a message indicating handover from a source cell to a target cell, wherein the message is transmitted using a transmit power determined based on information from the source cell regarding a scaling factor for the target cell, the scaling factor being applied to a path loss estimate for the target cell. According to embodiments of this disclosure, the circuitry can be configured to perform any of the methods implemented by the network device as discussed above.

[0189] As used herein, the term "circuit" can refer to hardware circuitry and / or a combination of hardware and software circuitry. For example, a circuit can be a combination of analog and / or digital hardware circuitry with software / firmware. As another example, a circuit can be any part of a hardware processor with software, including digital signal processors, software, and memory, which work together to enable a device (such as a terminal device or network device) to perform various functions. In yet another example, a circuit can be hardware circuitry and / or a processor (such as a microprocessor or a portion thereof) that requires software / firmware to operate, but which may be absent when operation is not required. As used herein, the term "circuit" also encompasses a specific implementation of hardware circuitry or a processor alone, or a portion thereof, and its accompanying software and / or firmware.

[0190] According to embodiments of this disclosure, a terminal device is provided. The terminal device includes: components for adjusting a transmission power for the target cell based on remaining time associated with a determination of the result of a handover from a source cell to a target cell; and components for transmitting a message indicating the handover to the target cell using the adjusted transmission power. In some embodiments, the first device may include components for performing corresponding operations of method 700A. In some example embodiments, the first device may also include components for performing other operations of some example embodiments of method 700A. The components may be implemented in any suitable form. For example, the components may be implemented as circuitry or software modules.

[0191] According to embodiments of this disclosure, a network apparatus is provided. The network apparatus includes: components for receiving from a terminal device a message indicating a handover from a source cell to a target cell, and wherein the message is transmitted using a transmit power adjusted based on the remaining time associated with a determination of the result of the handover. In some embodiments, a second component may include components for performing corresponding operations of method 700B. In some example embodiments, the second component may also include components for performing other operations of some example embodiments of method 700B. This component may be implemented in any suitable form. For example, the component may be implemented as a circuit or a software module.

[0192] According to embodiments of this disclosure, a network apparatus is provided. The network apparatus includes: components for transmitting an indication of a duration to a terminal device, the duration being associated with a transmit power adjustment for transmitting a message indicating handover from a source cell to a target cell. In some embodiments, a third component may include components for performing corresponding operations of method 700C. In some example embodiments, the third component may also include components for performing other operations of some example embodiments of method 700C. This component may be implemented in any suitable form. For example, the component may be implemented as a circuit or a software module.

[0193] According to embodiments of this disclosure, a terminal device is provided. The terminal device includes: components for receiving information from a source cell regarding an adjustment state of power control for a target cell; components for determining a transmission power for the target cell based on the information; and components for transmitting a message indicating a transfer from the source cell to the target cell using the transmission power. In some embodiments, a fourth component may include components for performing corresponding operations of method 800A. In some example embodiments, the fourth component may also include components for performing other operations of some example embodiments of method 800A. This component may be implemented in any suitable form. For example, the component may be implemented as a circuit or a software module.

[0194] According to embodiments of this disclosure, a network apparatus is provided. The network apparatus includes: components for sending information to a terminal device regarding an adjustment state for power control of a target cell, wherein the terminal device will perform a handover from the source cell to the target cell. In some embodiments, a fifth component may include components for performing corresponding operations of method 800B. In some example embodiments, the fifth component may also include components for performing other operations of some example embodiments of method 800B. This component may be implemented in any suitable form. For example, the component may be implemented as a circuit or a software module.

[0195] According to embodiments of this disclosure, a network apparatus is provided. The network apparatus includes: components for receiving from a terminal device a message indicating a handover from a source cell to a target cell, wherein the message is transmitted using a transmit power determined based on information from the source cell regarding an adjustment state of power control for the target cell. In some embodiments, a sixth component may include components for performing corresponding operations of method 800C. In some example embodiments, the sixth component may also include components for performing other operations of some example embodiments of method 800C. This component may be implemented in any suitable form. For example, the component may be implemented as a circuit or a software module.

[0196] According to embodiments of this disclosure, a terminal device is provided. The terminal device includes: components for receiving information from a source cell regarding a scaling factor for a target cell, the scaling factor being applied to a path loss estimate for the target cell; components for determining a transmission power for the target cell based on the information and the path loss estimate; and components for transmitting a message indicating a handover from the source cell to the target cell using the transmission power. In some embodiments, a seventh component may include components for performing corresponding operations of method 900A. In some example embodiments, the seventh component may also include components for performing other operations of some example embodiments of method 900A. This component may be implemented in any suitable form. For example, the component may be implemented as a circuit or a software module.

[0197] According to embodiments of this disclosure, a network apparatus is provided. The network apparatus includes: components for transmitting information to a terminal device regarding a scaling factor for a target cell, the scaling factor being applied to a path loss estimate for the target cell, wherein the terminal device will perform a handover from a source cell to the target cell. In some embodiments, an eighth component may include components for performing corresponding operations of method 900B. In some example embodiments, the eighth component may also include components for performing other operations of some example embodiments of method 900B. This component may be implemented in any suitable form. For example, the component may be implemented as a circuit or a software module.

[0198] According to embodiments of this disclosure, a network apparatus is provided. The network apparatus includes: components for receiving from a terminal device a message indicating handover from a source cell to a target cell, wherein the message is transmitted using a transmit power determined based on information from the source cell regarding a scaling factor for the target cell, the scaling factor being applied to a path loss estimate for the target cell. In some embodiments, a ninth component may include components for performing corresponding operations of method 900C. In some example embodiments, the ninth component may also include components for performing other operations of some example embodiments of method 900C. This component may be implemented in any suitable form. For example, the component may be implemented as a circuit or a software module.

[0199] In summary, the implementation scheme disclosed herein provides the following aspects.

[0200] In one aspect, a terminal device is proposed, comprising: a processor configured to cause the terminal device to: adjust a transmission power for the target cell based on a remaining time associated with a determination of the result of a handover from a source cell to a target cell; and transmit a message indicating the handover to the target cell using the adjusted transmission power.

[0201] In some implementations, the terminal device is configured to: determine an adjustment state for power control of the target cell based on the remaining time and the round-trip time for the target cell; and adjust the transmit power based on the adjustment state.

[0202] In some implementations, the adjustment state is determined based on the following: the remaining time, the round-trip time, the maximum transmission power supported by the terminal device, and another transmission power previously used to transmit the message.

[0203] In some implementations, the terminal device is further configured to determine the remaining time based on a first time length for power adjustment and a second time length elapsed since the source cell received the command for the handover.

[0204] In some implementations, the terminal device is further configured to: upon receiving the command, start a first timer for the handover to the target cell and a second timer for the transmit power adjustment having the first time length.

[0205] In some implementations, the terminal device is further configured to receive an indication of the first time length from the source cell.

[0206] In some implementations, the first time length is shorter than the effective time length of the first timer used for the handover to the target cell.

[0207] In some implementations, the terminal device is further configured to determine the remaining time based on: the effective duration of a first timer for the handover to the target cell, the time difference between the expiration of the first timer and the termination of the transmit power adjustment, and a second duration of time elapsed since the source cell received the command for the handover.

[0208] In some implementations, the terminal device is further configured to receive an indication of the time difference from the source cell.

[0209] In some implementations, the terminal device is further configured to determine the remaining time based on a third time length for power adjustment and a fourth time length elapsed since the target cell has been decoded and authorized.

[0210] In some implementations, the terminal device is further configured to: when decoding the authorization, start a third timer with the third time length for the transmission power adjustment.

[0211] In some implementations, the terminal device is further configured to receive an indication of the third time length from the source cell.

[0212] In one aspect, a network device is proposed, comprising: a processor configured to cause the network device providing a target cell to: receive from a terminal device a message indicating a handover from a source cell to the target cell, and wherein the message is transmitted using a transmit power adjusted based on a remaining time determined in relation to the result of the handover.

[0213] In one aspect, a network device is proposed, comprising: a processor configured to cause the network device providing a source cell to: send an indication of a duration associated with a transmit power adjustment for sending a message indicating handover from the source cell to a target cell.

[0214] In some implementations, the time length includes at least one of the following: a first time length for transmitting power adjustment and initiated upon receiving a command for the handover from the source cell, the time difference between the expiration of a first timer for the handover to the target cell and the termination of the transmitting power adjustment, or a third time length for transmitting power adjustment and initiated upon decoding authorization from the target cell.

[0215] In one aspect, a terminal device is proposed, comprising: a processor configured to cause the terminal device to: receive from a source cell information about an adjustment state of power control for a target cell; determine, based on the information, a transmission power for the target cell; and use the transmission power to send to the target cell a message indicating a handover from the source cell to the target cell.

[0216] In some implementations, the information indicates the value of the adjustment state, and the transmission power is determined based on the indicated value.

[0217] In some implementations, the information indicates the difference between the adjustment state and another adjustment state for power control of the source cell, and the transmit power is determined based on the difference and the other adjustment state.

[0218] In some implementations, this information is received in the command used for the handover.

[0219] In one aspect, a network device is proposed, comprising: a processor configured to cause the network device providing a source cell to: send information to a terminal device regarding an adjustment state for power control of a target cell, wherein the terminal device will perform a handover from the source cell to the target cell.

[0220] In some implementations, this information indicates the value of the adjustment state.

[0221] In some implementations, this information indicates the difference between the adjustment state and another adjustment state used for power control of the source cell.

[0222] In some implementations, this information is sent in the command used for the handover.

[0223] In one aspect, a network device is proposed, comprising: a processor configured to cause the network device providing a target cell to: receive from a terminal device a message indicating a handover from a source cell to the target cell, wherein the message is transmitted using a transmit power determined based on information from the source cell regarding an adjustment state for power control of the target cell.

[0224] In one aspect, a terminal device is proposed, comprising: a processor configured to cause the terminal device to: receive from a source cell information about a scaling factor for a target cell, the scaling factor being applied to a path loss estimate for the target cell; determine a transmission power for the target cell based on the information and the path loss estimate; and use the transmission power to transmit to the target cell a message indicating a handover from the source cell to the target cell.

[0225] In some implementations, this information indicates the value of the scaling factor, and the transmit power is determined based on the indicated value and the path loss estimate.

[0226] In some implementations, the information indicates the ratio of the scaling factor to another scaling factor associated with the random access procedure, and the transmit power is determined based on the indicated ratio, the other scaling factor, and the path loss estimate.

[0227] In one aspect, a network device is proposed, comprising: a processor configured to cause the network device providing a source cell to: send information to a terminal device about a scaling factor for a target cell, the scaling factor being applied to a path loss estimate for the target cell, wherein the terminal device will perform a handover from the source cell to the target cell.

[0228] In some implementations, this information indicates the value of the scaling factor.

[0229] In some implementations, this information indicates the ratio of the scaling factor to another scaling factor associated with the random access procedure.

[0230] In one aspect, a network device is proposed, comprising: a processor configured to cause the network device providing a target cell to: receive from a terminal device a message indicating a handover from a source cell to the target cell, wherein the message is transmitted using a transmit power determined based on information from the source cell regarding a scaling factor for the target cell, the scaling factor being applied to a path loss estimate for the target cell.

[0231] In one aspect, a terminal device includes: at least one processor; and at least one memory coupled to the at least one processor and storing instructions that, when executed by the at least one processor, cause the device to perform the methods implemented by the terminal device as discussed above.

[0232] In one aspect, a network device includes: at least one processor; and at least one memory coupled to the at least one processor and storing instructions that, when executed by the at least one processor, cause the device to perform the methods implemented by the network device as discussed above.

[0233] In one aspect, a computer-readable medium storing instructions that, when executed on at least one processor, cause the at least one processor to perform the methods implemented by the terminal device discussed above.

[0234] In one aspect, a computer-readable medium stores instructions that, when executed on at least one processor, cause the at least one processor to perform the methods implemented by the network device discussed above.

[0235] In one aspect, a computer program includes instructions that, when executed on at least one processor, cause the at least one processor to perform the methods discussed above and implemented by the terminal device.

[0236] In one aspect, a computer program includes instructions that, when executed on at least one processor, cause the at least one processor to perform the methods implemented by the network device discussed above.

[0237] Generally, various embodiments of this disclosure can be implemented in hardware or special-purpose circuitry, software, logic, or any combination thereof. Some aspects can be implemented in hardware, while others can be implemented in firmware or software executable by a controller, microprocessor, or other computing device. Although various aspects of embodiments of this disclosure are illustrated and described using block diagrams, flowcharts, or other illustrations, it should be understood that, as non-limiting examples, the blocks, apparatuses, systems, techniques, or methods described herein can be implemented in hardware, software, firmware, special-purpose circuitry or logic, general-purpose hardware or controllers or other computing devices, or any combination thereof.

[0238] This disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions (such as those included in program modules) that execute on a target real or virtual processor in a device to perform the functions described above. Figures 1 to 10 The described process or method. Generally, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc., that perform specific tasks or implement specific abstract data types. The functionality of a program module can be combined in various implementation schemes or split among program modules as needed. The machine-executable instructions used for a program module can be executed on a local or distributed device. In a distributed device, a program module can reside on both local and remote storage media.

[0239] Program code used to perform the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that, when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a stand-alone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0240] The aforementioned program code may be embodied on a machine-readable medium, which may be any tangible medium containing or storing a program used by or in connection with an instruction execution system, apparatus, or device. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media may include, but are not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. More specific examples of machine-readable storage media will include electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0241] Furthermore, although the operations are described in a specific order, this should not be construed as requiring such operations to be performed in the specific order shown or in sequential order, or to perform all the illustrated operations to achieve the desired result. In some environments, multitasking and parallel processing can be advantageous. While several specific implementation details are included in the foregoing discussion, these details should not be construed as limiting the scope of this disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features described in the context of individual embodiments may also be implemented in a single embodiment in combination. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0242] Although this disclosure has been described using language specific to structural features and / or methodological actions, it should be understood that the disclosure as defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are disclosed as examples of implementing the claims.

Claims

1. A terminal device, the terminal device comprising: Processor, the processor being configured to cause the terminal device to: The transmit power for the target cell is adjusted based on the remaining time associated with the determination of the result of the handover from the source cell to the target cell; and The handover message is sent to the target cell using the adjusted transmission power.

2. The terminal device according to claim 1, wherein the terminal device is configured to: The adjustment state for power control of the target cell is determined based on the remaining time and the round-trip time for the target cell; and The transmission power is adjusted based on the adjustment state.

3. The terminal device according to claim 2, wherein the adjustment state is determined based on the following: The remaining time. The round-trip time. The maximum transmission power supported by the terminal device, and The other transmission power previously used to send the message.

4. The terminal device according to claim 1, wherein the terminal device is further configured such that: The remaining time is determined based on the following: The first time length used for power adjustment, and The second time elapsed since the source cell received the command for the handover.

5. The terminal device according to claim 4, wherein the terminal device is further configured such that: Upon receiving the command, a first timer for the handover to the target cell and a second timer with the first time length for the transmission power adjustment are started.

6. The terminal device according to claim 4, wherein the terminal device is further configured such that: Receive an indication of the first time length from the source cell.

7. The terminal device according to claim 4, wherein the first time length is shorter than the effective time length of the first timer used for the handover to the target cell.

8. The terminal device according to claim 1, wherein the terminal device is further configured such that: The remaining time is determined based on the following: The effective time length of the first timer used for the handover to the target cell. The time difference between the expiration of the first timer and the termination of the transmit power adjustment, and The second time elapsed since the source cell received the command for the handover.

9. The terminal device according to claim 8, wherein the terminal device is further configured such that: Receive the indication of the time difference from the source cell.

10. The terminal device according to claim 1, wherein the terminal device is further configured such that: The remaining time is determined based on the following: The third time length used for power adjustment, and The fourth time elapsed since the target cell was authorized to decode.

11. The terminal device according to claim 10, wherein the terminal device is further configured such that: When decoding the authorization, a third timer with the third time length is started for the transmission power adjustment.

12. The terminal device according to claim 10, wherein the terminal device is further configured such that: Receive the indication of the third time length from the source cell.

13. A network device, the network device comprising: A processor, configured to cause the network device providing the target cell to: The terminal device receives a message instructing the transfer of the cell from the source cell to the target cell, and The message is transmitted using a transmission power adjusted based on the remaining time associated with the determination of the handover result.

14. A network device, the network device comprising: A processor, configured to cause the network device providing the source cell to: An indication of the duration of time is sent to the terminal device, the duration being associated with a transmission power adjustment used to send a message indicating a handover from the source cell to the target cell.

15. The network device of claim 14, wherein the duration includes at least one of the following: A first time length, the first time length being used to transmit power adjustment and initiated upon receiving a command for the handover from the source cell, The time difference between the expiration of the first timer used for the handover to the target cell and the termination of the transmit power adjustment, or A third time length is used for transmit power adjustment and to initiate decoding authorization from the target cell.

16. A terminal device, the terminal device comprising: Processor, the processor being configured to cause the terminal device to: Receive information from the source cell about the adjustment status for power control of the target cell; The transmission power for the target cell is determined based on the information. as well as The transmit power is used to send a message to the target cell indicating a handover from the source cell to the target cell.

17. The terminal device of claim 16, wherein the information indicates a value of the adjustment state, and the transmission power is determined based on the indicated value.

18. The terminal device of claim 16, wherein the information indicates a difference between the adjustment state and another adjustment state for power control of the source cell, and the transmit power is determined based on the difference and the other adjustment state.

19. The terminal device of claim 16, wherein the information is received in a command for the handover.

20. A network device, the network device comprising: A processor, configured to cause the network device providing the source cell to: Information about the adjustment status of power control for a target cell is sent to a terminal device, wherein the terminal device will perform a handover from the source cell to the target cell.

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