WO2024071850A1

WO2024071850A1 - Communication method, terminal, network node device and storage medium

Info

Publication number: WO2024071850A1
Application number: PCT/KR2023/014486
Authority: WO
Inventors: Jingxing Fu; Feifei SUN; Zhe Chen
Original assignee: Samsung Electronics Co., Ltd.
Priority date: 2022-09-28
Filing date: 2023-09-22
Publication date: 2024-04-04
Also published as: CN117835352A

Abstract

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. Embodiments of the present disclosure provide a communication method, a terminal, a network node device and a storage medium, and belong to the technical field of wireless communication. The communication method comprises: receiving first information, the first information indicating a UE to hand over from a first cell to a second cell; and monitoring PDCCHs in at least one of the first cell and the second cell. Based on the solutions provided in the present disclosure, the communication requirements can be better met.

Description

COMMUNICATION METHOD, TERMINAL, NETWORK NODE DEVICE AND STORAGE MEDIUM

Embodiments of the present disclosure relate to the field of wireless communication, and in particular to a communication method, a terminal, a network node device and a storage medium.

5G mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and can be implemented not only in “Sub 6GHz” bands such as 3.5GHz, but also in “Above 6GHz” bands referred to as mmWave including 28GHz and 39GHz. In addition, it has been considered to implement 6G mobile communication technologies (referred to as Beyond 5G systems) in terahertz bands (for example, 95GHz to 3THz bands) in order to accomplish transmission rates fifty times faster than 5G mobile communication technologies and ultra-low latencies one-tenth of 5G mobile communication technologies.

At the beginning of the development of 5G mobile communication technologies, in order to support services and to satisfy performance requirements in connection with enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), there has been ongoing standardization regarding beamforming and massive MIMO for mitigating radio-wave path loss and increasing radio-wave transmission distances in mmWave, supporting numerologies (for example, operating multiple subcarrier spacings) for efficiently utilizing mmWave resources and dynamic operation of slot formats, initial access technologies for supporting multi-beam transmission and broadbands, definition and operation of BWP (BandWidth Part), new channel coding methods such as a LDPC (Low Density Parity Check) code for large amount of data transmission and a polar code for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing a dedicated network specialized to a specific service.

Currently, there are ongoing discussions regarding improvement and performance enhancement of initial 5G mobile communication technologies in view of services to be supported by 5G mobile communication technologies, and there has been physical layer standardization regarding technologies such as V2X (Vehicle-to-everything) for aiding driving determination by autonomous vehicles based on information regarding positions and states of vehicles transmitted by the vehicles and for enhancing user convenience, NR-U (New Radio Unlicensed) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, NR UE Power Saving, Non-Terrestrial Network (NTN) which is UE-satellite direct communication for providing coverage in an area in which communication with terrestrial networks is unavailable, and positioning.

Moreover, there has been ongoing standardization in air interface architecture/protocol regarding technologies such as Industrial Internet of Things (IIoT) for supporting new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for providing a node for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner, mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access for simplifying random access procedures (2-step RACH for NR). There also has been ongoing standardization in system architecture/service regarding a 5G baseline architecture (for example, service based architecture or service based interface) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) for receiving services based on UE positions.

As 5G mobile communication systems are commercialized, connected devices that have been exponentially increasing will be connected to communication networks, and it is accordingly expected that enhanced functions and performances of 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research is scheduled in connection with eXtended Reality (XR) for efficiently supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality) and the like, 5G performance improvement and complexity reduction by utilizing Artificial Intelligence (AI) and Machine Learning (ML), AI service support, metaverse service support, and drone communication.

Furthermore, such development of 5G mobile communication systems will serve as a basis for developing not only new waveforms for providing coverage in terahertz bands of 6G mobile communication technologies, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas and large-scale antennas, metamaterial-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional space multiplexing technology using OAM (Orbital Angular Momentum), and RIS (Reconfigurable Intelligent Surface), but also full-duplex technology for increasing frequency efficiency of 6G mobile communication technologies and improving system networks, AI-based communication technology for implementing system optimization by utilizing satellites and AI (Artificial Intelligence) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology for implementing services at levels of complexity exceeding the limit of UE operation capability by utilizing ultra-high-performance communication and computing resources.

The present disclosure relates to wireless communication systems and, more specifically, the present disclosure relates to a network node device and storage medium.

The embodiments of the present disclosure provide a communication method, a terminal, a network node device and a storage medium, which can better satisfy the wireless communication requirements. The present disclosure employs the following technical solutions.

In one aspect, an embodiment of the present disclosure provides a method executed by a user equipment in a wireless communication system, including:

receiving first information, the first information indicating a UE to hand over from a first cell to a second cell; and

monitoring PDCCHs in the first cell and the second cell; or, monitoring PDCCHs in the second cell, and monitoring PDCCHs in the first cell and stopping monitoring PDCCHs in the second cell when a first condition is met.

In another aspect, an embodiment of the present disclosure provides a method executed by a network node device in a wireless communication system, including:

transmitting first information, the first information indicating a UE to hand over from a first cell to a second cell; and

transmitting PDCCHs in the first cell and the second cell;

or, transmitting PDCCHs in the second cell when a six condition is met, and transmitting PDCCHs in the first cell when the sixth condition is not met.

In another aspect, an embodiment of the present disclosure further provides a user equipment, including:

at least one transceiver; and

at least one processor, which is coupled to the transceiver and configured to execute the method executed by a user equipment according to the embodiments of the present disclosure.

In another aspect, an embodiment of the present disclosure further provides a network entity, including:

at least one transceiver; and

at least one processor, which is coupled to the transceiver and configured to execute the method executed by a network entity according to the embodiments of the present disclosure.

The beneficial effects of the technical solutions provided by the present disclosure will be described hereinafter by specific optional embodiments.

According to an embodiment of the disclosure, a wireless data communication service can be performed efficiently.

FIG. 1 is a schematic structure diagram of a wireless network according to an embodiment of the present disclosure;

FIG. 2a is a schematic diagram of a wireless transmission path according to an embodiment of the present disclosure;

FIG. 2b is a schematic diagram of a wireless reception path according to an embodiment of the present disclosure;

FIG. 3a is a schematic structure diagram of a terminal (user equipment) according to an embodiment of the present disclosure;

FIG. 3b is a schematic structure diagram of a base station according to an embodiment of the present disclosure;

FIG. 4 is a schematic flowchart of a communication method according to an embodiment of the present disclosure;

FIG. 5 is a schematic flowchart of a communication method according to an embodiment of the present disclosure;

FIG. 6 is a schematic principle diagrams of multiple optional methods for monitoring PDCCHs according to the present disclosure;

FIG. 7 is a schematic principle diagrams of multiple optional methods for monitoring PDCCHs according to the present disclosure;

FIG. 8 is a schematic principle diagrams of multiple optional methods for monitoring PDCCHs according to the present disclosure;

FIG. 9 is a schematic principle diagrams of multiple optional methods for monitoring PDCCHs according to the present disclosure;

FIG. 10 is a schematic principle diagrams of multiple optional methods for monitoring PDCCHs according to the present disclosure; and

FIG. 11 is a schematic structure diagram of an electronic device according to an embodiment of the present disclosure.

In order to meet the increasing demand for wireless data communication services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also called “Beyond 4G networks” or “Post-LTE systems”.

In order to achieve a higher data rate, 5G communication systems are implemented in higher frequency (millimeter, mmWave) bands, e.g., 60GHz bands. In order to reduce propagation loss of radio waves and increase a transmission distance, technologies such as beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antenna, analog beamforming and large-scale antenna are discussed in 5G communication systems.

In addition, in 5G communication systems, developments of system network improvement are underway based on advanced small cell, cloud radio access network (RAN), ultra-dense network, device-to-device (D2D) communication, wireless backhaul, mobile network, cooperative communication, coordinated multi-points (CoMP), reception-end interference cancellation, etc.

In 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) as advanced coding modulation (ACM), and filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) as advanced access technologies have been developed.

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustration purpose only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.

It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.

The term “include” or “may include” refers to the existence of a corresponding disclosed function, operation or component which can be used in various embodiments of the present disclosure and does not limit one or more additional functions, operations, or components. The terms such as “include” and/or “have” may be construed to denote a certain characteristic, number, step, operation, constituent element, component or a combination thereof, but may not be construed to exclude the existence of or a possibility of addition of one or more other characteristics, numbers, steps, operations, constituent elements, components or combinations thereof.

The term “or” used in various embodiments of the present disclosure includes any or all of combinations of listed words. For example, the expression “A or B” may include A, may include B, or may include both A and B.

Unless defined differently, all terms used herein, which include technical terminologies or scientific terminologies, have the same meaning as that understood by a person skilled in the art to which the present disclosure belongs. Such terms as those defined in a generally used dictionary are to be interpreted to have the meanings equal to the contextual meanings in the relevant field of art, and are not to be interpreted to have ideal or excessively formal meanings unless clearly defined in the present disclosure.

FIG. 1 illustrates an example wireless network 100 according to various embodiments of the present disclosure. The embodiment of the wireless network 100 shown in FIG. 1 is for illustration only. Other embodiments of the wireless network 100 can be used without departing from the scope of the present disclosure.

The wireless network 100 includes a gNodeB (gNB) 101, a gNB 102, and a gNB 103. The gNB 101 communicates with the gNB 102 and gNB 103. The gNB 101 also communicates with at least one Internet Protocol (IP) network 130, such as the Internet, a private IP network, or other data network.

Depending on a type of the network, other well-known terms such as “base station” or “access point” can be used instead of “gNodeB” or “gNB”. For convenience, the terms “gNodeB” and “gNB” are used in this patent document to refer to network infrastructure components that provide wireless access for remote terminals. And, depending on the type of the network, other well-known terms such as “mobile station”, “user station”, “remote terminal”, “wireless terminal” or “user apparatus” can be used instead of “user equipment” or “UE”. For convenience, the terms “user equipment” and “UE” are used in this patent document to refer to remote wireless devices that wirelessly access the gNB, no matter whether the UE is a mobile device (such as a mobile phone or a smart phone) or a fixed device (such as a desktop computer or a vending machine).

The gNB 102 provides wireless broadband access to the network 130 for a plurality of first User Equipments (UEs) within a coverage area 120 of the gNB 102. The plurality of first UEs include a UE 111, which may be located in a Small Business (SB); a UE 112, which may be located in an enterprise (E); a UE 113, which may be located in a WiFi Hotspot (HS); a UE 114, which may be located in a first residence (R); a UE 115, which may be located in a second residence (R); a UE 116, which may be a mobile device (M), such as a cellular phone, a wireless laptop computer, a wireless PDA, etc. The gNB 103 provides wireless broadband access to the network 130 for a plurality of second UEs within the coverage area 125 of the gNB 103. The plurality of second UEs include a UE 115 and a UE 116. In some embodiments, one or more of gNBs 101-103 can communicate with each other and with UEs 111-116 using 5G, Long Term Evolution (LTE), LTE-A, WiMAX or other advanced wireless communication technologies.

The dashed lines show approximate ranges of the

coverage areas

120 and 125, and the ranges are shown as approximate circles merely for illustration and explanation purposes. It should be clearly understood that the coverage areas associated with the gNBs, such as the

coverage areas

120 and 125, may have other shapes, including irregular shapes, depending on configurations of the gNBs and changes in the radio environment associated with natural obstacles and man-made obstacles.

As will be described in more detail below, one or more of gNB 101, gNB 102, and gNB 103 include a 2D antenna array as described in embodiments of the present disclosure. In some embodiments, one or more of gNB 101, gNB 102, and gNB 103 support codebook designs and structures for systems with 2D antenna arrays.

Although FIG. 1 illustrates an example of a wireless network 100, it may make various changes to FIG. 1. For example, wireless network 100 may include any number of gNBs and any number of UEs in any suitable arrangement. Furthermore, the gNB 101 can directly communicate with any number of UEs and provide wireless broadband access to the network 130 for those UEs. Similarly, each gNB 102-103 can directly communicate with the network 130 and provide direct wireless broadband access to the network 130 for the UEs. In addition,

gNB

101, 102 and/or 103 can provide access to other or additional external networks, such as external telephone networks or other types of data networks.

FIGs. 2a and 2b illustrate example wireless transmission and reception paths according to the present disclosure. In the following description, the transmission path 200 can be described as being implemented in a gNB, such as gNB 102, and the reception path 250 can be described as being implemented in a UE, such as UE 116. However, it should be understood that the reception path 250 can be implemented in a gNB and the transmission path 200 can be implemented in a UE. In some embodiments, the reception path 250 is configured to support codebook designs and structures for systems with 2D antenna arrays as described in embodiments of the present disclosure.

The transmission path 200 includes a channel coding and modulation block 205, a Serial-to-Parallel (S-to-P) block 210, a size N Inverse Fast Fourier Transform (IFFT) block 215, a Parallel-to-Serial (P-to-S) block 220, a cyclic prefix addition block 225, and an up-converter (UC) 230. The reception path 250 includes a down-converter (DC) 255, a cyclic prefix removal block 260, a Serial-to-Parallel (S-to-P) block 265, a size N Fast Fourier Transform (FFT) block 270, a Parallel-to-Serial (P-to-S) block 275, and a channel decoding and demodulation block 280.

In the transmission path 200, the channel coding and modulation block 205 receives a set of information bits, applies coding (such as Low Density Parity Check (LDPC) coding), and modulates the input bits (such as using Quadrature Phase Shift Keying (QPSK) or Quadrature Amplitude Modulation (QAM)) to generate a sequence of frequency-domain modulated symbols. The Serial-to-Parallel (S-to-P) block 210 converts (such as demultiplexes) serial modulated symbols into parallel data to generate N parallel symbol streams, where N is a size of the IFFT/FFT used in gNB 102 and UE 116. The size N IFFT block 215 performs IFFT operations on the N parallel symbol streams to generate a time-domain output signal. The Parallel-to-Serial block 220 converts (such as multiplexes) parallel time-domain output symbols from the Size N IFFT block 215 to generate a serial time-domain signal. The cyclic prefix addition block 225 inserts a cyclic prefix into the time-domain signal. The up-converter 230 modulates (such as up-converts) the output of the cyclic prefix addition block 225 to an RF frequency for transmission via a wireless channel. The signal can also be filtered at a baseband before switching to the RF frequency.

The RF signal transmitted from gNB 102 arrives at UE 116 after passing through the wireless channel, and operations in reverse to those at gNB 102 are performed at UE 116. The down-converter 255 down-converts the received signal to a baseband frequency, and the cyclic prefix removal block 260 removes the cyclic prefix to generate a serial time-domain baseband signal. The Serial-to-Parallel block 265 converts the time-domain baseband signal into a parallel time-domain signal. The Size N FFT block 270 performs an FFT algorithm to generate N parallel frequency-domain signals. The Parallel-to-Serial block 275 converts the parallel frequency-domain signal into a sequence of modulated data symbols. The channel decoding and demodulation block 280 demodulates and decodes the modulated symbols to recover the original input data stream.

Each of gNBs 101-103 may implement a transmission path 200 similar to that for transmitting to UEs 111-116 in the downlink, and may implement a reception path 250 similar to that for receiving from UEs 111-116 in the uplink. Similarly, each of UEs 111-116 may implement a transmission path 200 for transmitting to gNBs 101-103 in the uplink, and may implement a reception path 250 for receiving from gNBs 101-103 in the downlink.

Each of the components in FIGs. 2a and 2b can be implemented using only hardware, or using a combination of hardware and software/firmware. As a specific example, at least some of the components in FIGs. 2a and 2b may be implemented in software, while other components may be implemented in configurable hardware or a combination of software and configurable hardware. For example, the FFT block 270 and IFFT block 215 may be implemented as configurable software algorithms, in which the value of the size N may be modified according to the implementation.

Furthermore, although described as using FFT and IFFT, this is only illustrative and should not be interpreted as limiting the scope of the present disclosure. Other types of transforms can be used, such as Discrete Fourier transform (DFT) and Inverse Discrete Fourier Transform (IDFT) functions. It should be understood that for DFT and IDFT functions, the value of variable N may be any integer (such as 1, 2, 3, 4, etc.), while for FFT and IFFT functions, the value of variable N may be any integer which is a power of 2 (such as 1, 2, 4, 8, 16, etc.).

Although FIGs. 2a and 2b illustrate examples of wireless transmission and reception paths, various changes may be made to FIGs. 2a and 2b. For example, various components in FIGs. 2a and 2b can be combined, further subdivided or omitted, and additional components can be added according to specific requirements. Furthermore, FIGs. 2a and 2b are intended to illustrate examples of types of transmission and reception paths that can be used in a wireless network. Any other suitable architecture can be used to support wireless communication in a wireless network.

FIG. 3a illustrates an example UE 116 according to the present disclosure. The embodiment of UE 116 shown in FIG. 3a is for illustration only, and UEs 111-115 of FIG. 1 can have the same or similar configuration. However, a UE has various configurations, and FIG. 3a does not limit the scope of the present disclosure to any specific implementation of the UE.

UE 116 includes an antenna 305, a radio frequency (RF) transceiver 310, a transmission (TX) processing circuit 315, a microphone 320, and a reception (RX) processing circuit 325. UE 116 also includes a speaker 330, a processor/controller 340, an input/output (I/O) interface (IF) 345, an input device(s) 350, a display 355, and a memory 360. The memory 360 includes an operating system (OS) 361 and one or more applications 362.

The RF transceiver 310 receives an incoming RF signal transmitted by a gNB of the wireless network 100 from the antenna 305. The RF transceiver 310 down-converts the incoming RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is transmitted to the RX processing circuit 325, where the RX processing circuit 325 generates a processed baseband signal by filtering, decoding and/or digitizing the baseband or IF signal. The RX processing circuit 325 transmits the processed baseband signal to speaker 330 (such as for voice data) or to processor/controller 340 for further processing (such as for web browsing data).

The TX processing circuit 315 receives analog or digital voice data from microphone 320 or other outgoing baseband data (such as network data, email or interactive video game data) from processor/controller 340. The TX processing circuit 315 encodes, multiplexes, and/or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The RF transceiver 310 receives the outgoing processed baseband or IF signal from the TX processing circuit 315 and up-converts the baseband or IF signal into an RF signal transmitted via the antenna 305.

The processor/controller 340 can include one or more processors or other processing devices and execute an OS 361 stored in the memory 360 in order to control the overall operation of UE 116. For example, the processor/controller 340 can control the reception of forward channel signals and the transmission of backward channel signals through the RF transceiver 310, the RX processing circuit 325 and the TX processing circuit 315 according to well-known principles. In some embodiments, the processor/controller 340 includes at least one microprocessor or microcontroller.

The processor/controller 340 is also capable of executing other processes and programs residing in the memory 360, such as operations for channel quality measurement and reporting for systems with 2D antenna arrays as described in embodiments of the present disclosure. The processor/controller 340 can move data into or out of the memory 360 as required by an execution process. In some embodiments, the processor/controller 340 is configured to execute the application 362 based on the OS 361 or in response to signals received from the gNB or the operator. The processor/controller 340 is also coupled to an I/O interface 345, where the I/O interface 345 provides UE 116 with the ability to connect to other devices such as laptop computers and handheld computers. I/O interface 345 is a communication path between these accessories and the processor/controller 340.

The processor/controller 340 is also coupled to the input device(s) 350 and the display 355. An operator of UE 116 can input data into UE 116 using the input device(s) 350. The display 355 may be a liquid crystal display or other display capable of presenting text and/or at least limited graphics (such as from a website). The memory 360 is coupled to the processor/controller 340. A part of the memory 360 can include a random access memory (RAM), while another part of the memory 360 can include a flash memory or other read-only memory (ROM).

Although FIG. 3a illustrates an example of UE 116, various changes can be made to FIG. 3a. For example, various components in FIG. 3a can be combined, further subdivided or omitted, and additional components can be added according to specific requirements. As a specific example, the processor/controller 340 can be divided into a plurality of processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Furthermore, although FIG. 3a illustrates that the UE 116 is configured as a mobile phone or a smart phone, UEs can be configured to operate as other types of mobile or fixed devices.

FIG. 3b illustrates an example gNB 102 according to the present disclosure. The embodiment of gNB 102 shown in FIG. 3b is for illustration only, and other gNBs of FIG. 1 can have the same or similar configuration. However, a gNB has various configurations, and FIG. 3b does not limit the scope of the present disclosure to any specific implementation of a gNB. It should be noted that gNB 101 and gNB 103 can include the same or similar structures as gNB 102.

As shown in FIG. 3b, gNB 102 includes a plurality of antennas 370a-370n, a plurality of RF transceivers 372a-372n, a transmission (TX) processing circuit 374, and a reception (RX) processing circuit 376. In certain embodiments, one or more of the plurality of antennas 370a-370n include a 2D antenna array. gNB 102 also includes a controller/processor 378, a memory 380, and a backhaul or network interface 382.

RF transceivers 372a-372n receive an incoming RF signal from antennas 370a-370n, such as a signal transmitted by UEs or other gNBs. RF transceivers 372a-372n down-convert the incoming RF signal to generate an IF or baseband signal. The IF or baseband signal is transmitted to the RX processing circuit 376, where the RX processing circuit 376 generates a processed baseband signal by filtering, decoding and/or digitizing the baseband or IF signal. RX processing circuit 376 transmits the processed baseband signal to controller/processor 378 for further processing.

The TX processing circuit 374 receives analog or digital data (such as voice data, network data, email or interactive video game data) from the controller/processor 378. TX processing circuit 374 encodes, multiplexes and/or digitizes outgoing baseband data to generate a processed baseband or IF signal. RF transceivers 372a-372n receive the outgoing processed baseband or IF signal from TX processing circuit 374 and up-convert the baseband or IF signal into an RF signal transmitted via antennas 370a-370n.

The controller/processor 378 can include one or more processors or other processing devices that control the overall operation of gNB 102. For example, the controller/processor 378 can control the reception of forward channel signals and the transmission of backward channel signals through the RF transceivers 372a-372n, the RX processing circuit 376 and the TX processing circuit 374 according to well-known principles. The controller/processor 378 can also support additional functions, such as higher-level wireless communication functions. For example, the controller/processor 378 can perform a Blind Interference Sensing (BIS) process such as that performed through a BIS algorithm, and decode a received signal from which an interference signal is subtracted. A controller/processor 378 may support any of a variety of other functions in gNB 102. In some embodiments, the controller/processor 378 includes at least one microprocessor or microcontroller.

The controller/processor 378 is also capable of executing programs and other processes residing in the memory 380, such as a basic OS. The controller/processor 378 can also support channel quality measurement and reporting for systems with 2D antenna arrays as described in embodiments of the present disclosure. In some embodiments, the controller/processor 378 supports communication between entities such as web RTCs. The controller/processor 378 can move data into or out of the memory 380 as required by an execution process.

The controller/processor 378 is also coupled to the backhaul or network interface 382. The backhaul or network interface 382 allows gNB 102 to communicate with other devices or systems through a backhaul connection or through a network. The backhaul or network interface 382 can support communication over any suitable wired or wireless connection(s). For example, when gNB 102 is implemented as a part of a cellular communication system, such as a cellular communication system supporting 5G or new radio access technology or NR, LTE or LTE-A, the backhaul or network interface 382 can allow gNB 102 to communicate with other gNBs through wired or wireless backhaul connections. When gNB 102 is implemented as an access point, the backhaul or network interface 382 can allow gNB 102 to communicate with a larger network, such as the Internet, through a wired or wireless local area network or through a wired or wireless connection. The backhaul or network interface 382 includes any suitable structure that supports communication through a wired or wireless connection, such as an Ethernet or an RF transceiver.

The memory 380 is coupled to the controller/processor 378. A part of the memory 380 can include an RAM, while another part of the memory 380 can include a flash memory or other ROMs. In certain embodiments, a plurality of instructions, such as the BIS algorithm, are stored in the memory. The plurality of instructions are configured to cause the controller/processor 378 to execute the BIS process and decode the received signal after subtracting at least one interference signal determined by the BIS algorithm.

As will be described in more detail below, the transmission and reception paths of gNB 102 (implemented using RF transceivers 372a-372n, TX processing circuit 374 and/or RX processing circuit 376) support aggregated communication with FDD cells and TDD cells.

Although FIG. 3b illustrates an example of gNB 102, various changes may be made to FIG. 3b. For example, gNB 102 can include any number of each component shown in FIG. 3a. As a specific example, the access point can include many backhaul or network interfaces 382, and the controller/processor 378 can support routing functions to route data between different network addresses. As another specific example, although shown as including a single instance of the TX processing circuit 374 and a single instance of the RX processing circuit 376, gNB 102 can include multiple instances of each (such as one for each RF transceiver).

It should be understood that the solutions provided in the embodiments of the present disclosure can be applied to, but not limited to, the above wireless network.

The technical solutions of the present disclosure and how the technical solutions of the present application solve the above technical problems will be described below in detail by specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present disclosure will be described below with reference to the accompanying drawings.

In wireless communication systems, the transmission from a base station to a user equipment (UE) is called downlink, and the transmission from a UE to a base station is called uplink.

When a UE moves or meets other cell handover conditions, how to perform cell handover quickly is one of important aspects of the wireless communication system design. In the embodiments of the present disclosure, in order to reduce the delay of handover between cells, a handover command can be indicated by a medium access control (MAC) signaling or a physical layer signaling (e.g., downlink control information (DCI)), so that the handover operation is completed quickly. FIG. 4 shows a method executed by a UE in a wireless communication system according to an embodiment of the present disclosure. As shown in FIG. 4, the method may include the following steps.

In step S410, first information is received, the first information indicating the UE to hand over from a first cell to a second cell.

In step S420, information transmission is performed in at least one of the first cell and the second cell.

The performing information transmission includes monitoring PDCCHs (which may also be referred to as inspecting PDCCHs).

Optionally, the monitoring PDCCHs in at least one of the first cell and the second cell includes:

monitoring PDCCHs in the first cell and the second cell, or

monitoring PDCCHs in the second cell, and monitoring PDCCHs in the first cell and stopping monitoring PDCCHs in the second cell when a first condition is met.

There may be one or more first cells, and there may be one or more second cells.

Optionally, if there are a plurality of first cells and/or there are a plurality of second cells, the monitoring PDCCHs in the first cell includes: monitoring PDCCHs in at least one first cell; and

monitoring PDCCHs in the second cell includes: monitoring PDCCHs in at least one second cell.

In other words, PDCCHs may be monitored in at least one of the first cells and the second cells. Here, at least one of the first cells and the second cells refers to at least one of the first cells and/or at least one of the second cells.

Optionally, the method may further include: in response to the first information, performing cell handover by the UE. The information required for the UE to perform cell handover may be informed to the UE by the base station through the first information. That is, in addition to indicating the UE to perform cell handover, the first information may further include related information required for cell handover. Or, the information required for the UE to perform cell handover may also be informed to the UE by the UE through other information. For example, the base station may inform the UE of the information through cell configuration information (described hereinafter) or in other ways.

In the embodiment of the present disclosure, the first information is information for indicating the UE to perform cell handover, specifically indicating to hand over the serving cell of the UE to the second cell. For example, the first cell is the current serving cell of the UE, i.e., the serving cell before handover (which may also be called a source serving cell), and the second cell is a serving cell after handover, i.e., a target serving cell. For the convenience of description, hereinafter, the first cell is called a first serving cell, and the second cell is called a second serving cell.

Optionally, the UE may correspondingly have its own cell set (which may be called a candidate serving cell set or other names, which will not be limited in the embodiment of the present disclosure). The cells in the candidate serving cells may be called candidate serving cells, i.e., cells that may or can serve as serving cells of cells. The cell set may at least include the first serving cell and the second serving cell, or may also include one or more other cells in addition to the first serving cell and the second serving cell.

In the embodiment of the present disclosure, the first serving cell may be one serving cell, or two or more serving cells; and, the first serving cell may be a primary cell (Pcell), or may be a secondary cell (Scell), or may include a primary cell and at least one secondary cell. The second serving cell is a serving cell after handover (if the handover is successfully). Similarly, the second serving cell may be one cell, or two or more cells; and, the second serving cell may be a primary cell (Pcell), or may be a secondary cell (Scell), or may include a primary cell and at least one secondary cell.

In the embodiment of the present disclosure, the number of the first serving cell may be the same as or different from the number of the second serving cell. That is, the cell number relationship between the first serving cell and the second serving cell may be one-to-one, one-to-many, many-to-one, or many-to-many.

Optionally, the first serving cell and the second serving cell do not include overlapped cells. Optionally, the first serving cell and the second serving cell may also include partially overlapped cells.

Optionally, the receiving first information may include: receiving the first information through an MAC layer signaling or a physical layer signaling.

That is, the first information may be transmitted to the UE by the base station or a physical entity structure of the base station (e.g., a distributed unit of the base station) through an MAC layer signaling or a physical layer signaling. The first information may also be called a first signaling/command, a handover command, a cell handover command, etc. The specific information form or name of the first information will not be limited in the embodiment of the present disclosure. The first information may be explicit indication information or implicit indication information. For example, the first information may contain the identity or index of the second serving cell, and the UE may know the target serving cell according to the identity.

Optionally, the first signaling may be a physical layer signaling, and may be indicated by the base station or the physical entity of the base station through DCI. The DCI may indicate the cell index of the second serving cell, and the UE may determine, according to the cell index, that the second serving cell is which cell. As an example, if it is assumed that the candidate cell set of the UE includes a cell 1, a cell 2, a cell 3 and a cell 4 and the second serving cell is one cell, the base station may realize indication through 2 bits of DCI (the DCI may be the reuse of the existing DCI, or new DCI). For example, 00 represents the cell 1, 01 represents the cell 2, and so on. Upon receiving the first signaling transmitted by the base station, the UE may know, according the value of the two bits, that the second serving cell is which cell. Optionally, if there are a plurality of second serving cells, the base station may indicate the UE by using more bits or in other ways.

Optionally, the first signaling may be an MAC layer signaling, and the base station may realize indication by transmitting data. For example, the base station may indicate that the second serving cell is which cell or cells by using a bitmap containing 10 bits, assuming that the cell set of the UE includes 10 candidate service cells. Each bit of the bitmap corresponds to one cell, the value of 1 of the bit represents that the corresponding cell is the second serving cell, and the value of 0 of the bit represents that the corresponding cell is not the second serving cell. Upon receiving the first signaling, the UE may determine the target serving cell by parsing the signaling to obtain the bitmap.

Optionally, the second serving cell may include at least one of the primary cell or the secondary cell, and it may be protocoled or indicated by the indication of the base station or the protocol that which cell is the primary cell. For example, the base station may indicate, by DCI or one or more bits in the bitmap, that the primary cell and/or secondary cell after which handover of the UE is which cell.

Optionally, in addition to the handover indication information (the information indicating the UE to hand over form the first cell to the second cell), the first information may further include other information. For example, the first information may further include one or more of the random access related configuration (e.g., random access resource configuration), indication information for indicating whether the UE performs random access in the second serving cell, information required for the UE to perform cell handover, etc. When the first information includes the information for indicating that the UE performs random access, upon receiving the first information, the UE may start a random access process in the second serving cell, for example, performing random access according to the random access resource configuration in the first information, or performing random access according to the random cell resource configuration in the cell configuration information (described hereinafter) of the second serving cell.

In the method provided in the embodiment of the present disclosure, the handover of the serving cell of the UE can be indicated to the UE by the base station through a physical layer signaling or an MAC layer signaling. In this way, the delay of handover between cells can be effectively reduced, and the cell handover can be quickened.

Optionally, after the UE receives the first information, the method may further include: transmitting response information for the first information to the base station. Optionally, the response information for the first message may be acknowledgement information (ACK) for the first message, and the message is used for informing the base station that the handover command has been received by the UE. After the UE transmits the ACK, the base station may or may not receive the ACK.

Optionally, after the base station transmits the handover command to the UE, if the base station does not determine whether the UE has received the handover command, the base station may perform information transmission (e.g., transmitting PDCCHs) in the first serving cell, or may perform information transmission in the second serving cell, or may perform information transmission in both the first serving cell and the second serving cell. In order to avoid the information loss caused by cell handover as far as possible, in the method provided by the present disclosure, upon receiving the first information, the UE may perform information transmission in at least one of the first serving cell and the second serving cell.

In the embodiment of the present disclosure, the performing information transmission may include, but not limited to, transmitting control information and/or data, wherein the control information may include uplink control information and/or downlink control information, and the data may include uplink data and/or downlink data.

Optionally, for the UE, the performing information transmission may include monitoring PDCCHs. That is, performing, by the UE, information transmission in at least one of the first cell and the second cell includes: monitoring, by the UE, PDCCHs in at least one of the first cell and the second cell. Optionally, when the UE monitors PDCCHs transmitted by the base station, the UE may perform subsequent operations according to the specific information in the monitored PDCCHs.

FIG. 5 shows another schematic flowchart of the method according to an embodiment of the present disclosure. As shown in FIG. 5, the method may further include:

receiving cell configuration information about each of at least two cells, the at least two cells at least including the first cell and the second cell.

The receiving cell configuration information about each of at least two cells may include at least one of the following:

receiving cell configuration information about the first cell;

receiving cell configuration information about the second cell; and

receiving cell configuration information about other candidate cells, the other candidate cells being cells other than the first cell and the second cell.

Optionally, the cell configuration information about each of at least two cell may be received before the first information is received.

Correspondingly, during monitoring PDCCHs in the first cell, it monitors PDCCHs in the first cell according to the cell configuration information of the first cell. During monitoring PDCCHs in the second cell, it monitors PDCCHs in the second cell according to the cell configuration information of the second cell.

The at least two cells may be some or all of cells in the candidate serving cell set of the UE. For the UE, the base station may configure cell configuration information of each cell in the candidate cell set for the UE, wherein the cell configuration information at least includes the configuration information of each first serving cell and the configuration information of each second serving cell.

For a cell, the cell configuration information may include the configuration related to the information transmission performed by the UE (which may include at least one of the reception of downlink control information, the reception of downlink data, the transmission of uplink control information, the transmission of uplink data, and performing random access).

Optionally, the cell configuration information may include, but not limited to, one or more of the bandwidth part (BWP) configuration, PDCCH configuration, physical downlink shared channel (PDSCH) configuration, physical uplink control channel (PUCCH) configuration, physical uplink shared channel (PUSCH) configuration, search space configuration or other configurations of the cell.

The BWP configuration refers to the configuration related to the BWP of the cell, and each cell may be allocated with one or more BWPs. The BWP configuration may include, but not limited to, one or more of the BWP identity (or index) of the cell, information for indicating that which BWP is an activated BWP, information for indicating that which BWP is a default BWP, or other information.

The PDCCH configuration is the configuration information related to PDCCH transmission, for example, one or more of information for indicating the position of the time-domain resource and/or frequency-domain resource for PDCCH transmission, information for indicating the PDCCH transmission period, and the configuration related to the search space of PDCCHs.

Similarly, the PDSCH configuration is the configuration information related to PDSCH transmission, the PUCCH configuration is the configuration information related to PUCCH transmission, and the PUSCH configuration is the PUSCH related configuration information. The search space configuration may include the configuration related to the search space of PDCCHs, which may include, but not limited to, one or more of the configuration information related to the common search space (CSS) and the configuration information related to the UE specific search space (USS).

The specific way of providing, by the base station, the configuration information of each cell in the cell set of the UE to the UE will not be limited in the embodiment of the present disclosure. The configuration occasions of the configuration information of different cells may be the same or different. That is, the base station may provide the configuration information of each cell of the UE to the UE simultaneously or separately. For example, the base station may first transmit the configuration information of the first serving cell to the UE, and may transmit the configuration information of the second serving cell to the UE at a time no later than that time when the first information is transmitted to the UE.

Optionally, the configuration occasions of different configuration items in the cell configuration information of the same cell may be the same or different. For example, the configuration occasions of the PDCCH configuration and the PDSCH configuration may be the same or different. For example, it is possible to configure the PDCCH related configuration for the UE and then configure the PDSCH related configuration.

Optionally, the information elements contained in the cell configuration information of the first serving cell may be the same or different from those contained in the configuration information of other cells (e.g., the second serving cell) except for the first serving cell. For example, both the cell configuration information of the first serving cell and the cell configuration information of the second serving cell may include the PDCCH related configuration information. For another example, the cell configuration information of the second serving cell may include the configuration related to the random access of the UE on the second serving cell (based on this configuration, the UE may perform random access on the second serving cell); and, the first serving cell is the current serving cell of the UE, and the cell configuration information of the first serving cell may not contain the random access related configuration.

Optionally, the cell configuration information may include the configuration related to PDCCH transmission (called PDCCH configuration for short), and the UE may monitor PDCCHs in the at least one cell according to the PDCCH configuration of at least one of the first cell and the second cell. Optionally, the cell configuration information may further include the random access related configuration, e.g., the random access resource configuration. If the base station indicates, in the cell handover command, that the UE performs random access on the second serving cell, the UE may perform random access on the second serving cell according to the random access related configuration of the second serving cell.

In an optional embodiment of the present disclosure, the cell configuration information of any cell includes first configuration information and second configuration information.

When information transmission is performed in the first cell or the second cell, information transmission (e.g., monitoring PDCCHs) is performed in this cell based on the first configuration information of the corresponding cell. For example, when monitoring PDCCHs in only the first cell, it monitors PDCCHs in the first cell based on the first configuration information of the first cell; and, when monitoring PDCCHs in only the second cell, it monitors PDCCHs in the second cell based on the first configuration information of the second cell.

When information transmission is performed in the first cell and the second cell, information transmission is performed on the second configuration information of the first cell, and information transmission (e.g., monitoring PDCCHs) is performed based on the second configuration information of the second cell.

That is, one cell may have two sets of cell configuration information, i.e., the first configuration information (config1) and the second configuration information (config2), and the UE may perform information transmission by using the corresponding set of configurations in different situations. By taking monitoring PDCCHs as an example, when the UE monitors PDCCHs in only the source serving cell or the target serving cell, the UE may perform monitoring by using the configuration related to PDCCH monitoring in the config1 of the corresponding cell; and, when the UE monitors PDCCHs in both the source serving cell and the target serving cell, the UE may perform monitoring by using the configuration related to PDCCH monitoring in the config2 of the corresponding cell. Based on this method, the configuration mode for the UE can be more flexible. For the scheme in which the cell has two sets of configurations, the first set of configurations being used in which situation and the second set of configurations may be informed to the UE by the base station through the indication information, or may be protocoled. When the UE performs information transmission in the first cell or the second cell, the description form of performing information transmission in this cell based on the first configuration information of the corresponding cell will not be limited. For example, the UE monitors PDCCHs based on the first configuration information of the first cell within a first duration after receiving the first information, monitors PDCCHs based on the second configuration information of the first cell and the second configuration information of the second cell after the first duration, and stops monitoring PDCCHs in the first cell and monitors PDCCHs based on the first configuration information of the second cell when a second condition is met.

Various optional ways of performing information transmission provided in the embodiment of the present disclosure will be described below. It is to be noted that different implementations can be implemented separately or in combination if not conflicted.

In an optional embodiment of the present disclosure, the monitoring PDCCHs in the first cell and the second cell may include at least one of the following:

monitoring PDCCHs in the first cell and the second cell, and stopping monitoring PDCCHs in the first cell when the second condition is met;

monitoring PDCCHs in the first cell and the second cell, and stopping monitoring PDCCHs in the first cell when a third condition is met; and

monitoring PDCCHs in the first cell and the second cell, and triggering cell reselection when a fourth condition is met.

Optionally, the monitoring PDCCHs in the first cell and the second cell may include:

upon receiving the first information and before a first duration, monitoring PDCCHs in the first cell or the second cell, and after the first duration, monitoring PDCCHs in the first cell and the second cell.

Optionally, the monitoring PDCCHs in the second cell may include:

upon receiving the first information and before a second duration, monitoring PDCCHs in the first cell, and after the second duration, monitoring PDCCHs in the second cell and stopping monitoring PDCCHs in the first cell.

It is to be noted that each duration (e.g., the first duration, the second duration, the third duration, etc.) involved in the optional embodiments of the present disclosure may be indicated to the UE by the base station or may be protocoled, and some or all of the durations may be equal or not equal. The duration in the embodiment of the present disclosure may be a specific time length, e.g., specific few milliseconds, and the duration may also be a timing time in time units. For example, the duration may be at least one time unit. The time length of one time unit will not be limited in the embodiment of the present disclosure, and may be a slot, a half slot, a micro slot or other units.

As an optional solution, the UE may perform information transmission (e.g., monitoring PDCCHs) in only the first serving cell within a certain duration after receiving the handover command transmitted by the base station, and may perform information transmission in the second serving cell after the certain duration.

After the UE receives the handover command transmitted by the base station and knows that a serving cell handover needs to be performed by parsing the command, the UE may execute a cell handover operation (or it is also possible configure a certain condition and perform a handover after the condition is met). Optionally, the UE may monitor PDCCHs in only the first serving cell within a certain duration (second duration) after receiving the first information, and monitor PDCCHs in the second serving cell after the certain duration. In the example shown in FIG. 6, the horizontal solid line is the time line. The UE monitors PDCCHs in the first serving cell before the moment T after receiving the handover indication signaling (e.g., handover command); and, after the moment T after the UE receives the handover indication signaling, the UE monitors PDCCHs in the second serving cell, and the UE stops monitoring PDCCHs in the first serving cell. By using this solution, the UE can be quickly handed over to the target serving cell, so that the handover delay can be reduced, and the situation where the UE cannot monitor PDCCHs transmitted by the base station can be reduced.

Optionally, when the UE monitors PDCCHs in the second cell and the first condition is met, the UE may monitor PDCCHs in the first cell and stop monitoring PDCCHs in the second cell. The first condition being met may include at least one of the following:

the value of a first timer is 0, the initial value of the first timer being a first value, the value of the first timer decreasing progressively when a fifth condition is not met, and the value of the first timer being reset as the first value or the first timer being stopped when the fifth condition is met;

no PDCCH is monitored in the second cell within a third duration; and

no PDCCH is monitored in the second cell within a first number of continuous time units.

That is, when the UE performs information transmission (e.g., monitoring PDCCHs) in the second serving cell, the UE may determine whether to stop performing information transmission in the second serving cell according to the first condition. If the first condition is met, the UE may return to the first serving cell for information transmission and stop performing information transmission in the second serving cell. Based on this optional solution, the information loss caused when the base station continuously performs information transmission in the first serving cell but the UE performs information transmission in the second serving cell after the base station transmits the handover command is avoided.

For example, after the base station transmits the handover command, the base station does not receive the ACK of the command fed back by the UE, so that the base station still transmits PDCCHs in the first serving cell. However, since the UE has received the handover command, if the UE monitors PDCCHs in the second serving cell all the time, the UE will not monitor PDCCHs. Based on the optional solution disclosed by the present disclosure, when the UE monitors PDCCHs in the second serving cell and if the third condition is met, the UE will return to the first serving cell where the base station transmits PDDCHs to monitor PDCCHs.

It is to be noted that, the specific value of each number (e.g., the first number, and the second number and the third number hereinafter) in the embodiment of the present disclosure will not be limited, and the values of the first number, the second number and the third number may be the same or different.

The timer (the first timer, the second timer or the third timer) involved in the embodiment of the present disclosure may be called a timer, a counter, a timing device or other names. For example, the timer in the present disclosure may be called Cell-InactivityTimer.

The first timer may be used in the second serving cell, and this timer has an initial value. Optionally, the first timer starts to operate when the UE starts to perform data transmission in the second serving cell, and the timer starts to decrease progressively when a fifth condition is not met. For example, the initial value of the timer is a positive integer. Every time the fifth condition is not met, the numerical value of the timer decreases by 1. If the numerical value of the timer becomes 0, it may be considered that the timer is failed or expired. If the first condition is met, the UE may stop performing information transmission in the second serving cell and perform information transmission in the first serving cell. If the fifth condition is met, the first timer may be reset or stop timing, and the UE may continuously perform information transmission in the second serving cell.

Optionally, the fifth condition being met includes at least one of the following:

PDCCHs are monitored in the second cell within one or more time units; and, the UE completes random access in the second cell.

In this optional solution, if the UE performs PDCCH monitoring in the second serving cell and if PDCCHs (e.g., its own PDCCHs) have been monitored, it indicates that the base station transmits information to the UE in the second serving cell. At this time, the value of the first timer may be reset as the first value or the first timer may be stopped, and the UE may continuously perform information transmission in the second serving cell. If the UE does not monitor PDCCHs within one or more time units, the numerical value of the first timer may decrease progressively.

In another optional solution, whether the UE completes random access in the second serving cell may be used as a judgment condition. If the UE completes random access in the second serving cell, it indicates that the UE has established a connection with the network entity (network node device) corresponding to the second serving cell. At this time, the UE may no longer perform information transmission in the first serving cell, and the first timer may be stopped or reset as the first value.

Optionally, the first timer may be protocoled, and the UE may use this timer when the UE has received the cell handover command transmitted by the base station. The first timer may also be configured for the UE by the base station. Optionally, the method may further include:

receiving second configuration information, the second configuration information being used for configuring the first timer.

The specific way of configuring the first timer for the UE will not be limited in the embodiment of the present disclosure. Optionally, the first timer may be configured when the base station configures the cell configuration information for the UE, or may be configured separately. Optionally, the first timers corresponding to different cells may have the same or different initial values. The initial value of the first timer corresponding to the UE may also be related to the UE's capability, that is, the base station may also configure the first timer for the UE according to the capability configuration of the UE.

In an optional embodiment of the present disclosure, upon receiving the handover command transmitted by the base station, the UE may perform information transmission in both the first serving cell and the second serving cell. For example, the UE may monitor PDCCHs in both the first serving cell and the second serving cell, so that the information loss caused by the handover between serving cells is avoided.

Optionally, the UE may monitor PDCCHs in the first cell before a first duration after receiving the first information, and monitor PDCCHs in the first cell and the second cell after the first duration after receiving the first information.

That is, the UE may perform information transmission in only the first serving cell within a period of time after receiving the handover command, and the UE may perform information transmission in both the first serving cell and the second serving cell after this period of time. Optionally, since it takes a certain parsing time for the UE to know the command from the base station after receiving the handover command, the first duration may be configured, and the UE may still perform information transmission (e.g., PDCCH monitoring) in the serving cell within this duration after receiving the handover command.

Optionally, in order to avoid information loss as far as possible and save system resources, by taking performing information transmission being monitoring PDCCHs as an example, when the UE monitors PDCCHs in the first serving cell and monitors PDCCHs in the second serving cell, a certain condition may be set. If the certain condition is met, the UE may stop monitoring PDCCHs in the first serving cell or the second serving cell, and monitor PDCCHs in only the second serving cell or the first serving cell. As described above, the second condition is a condition for allowing the UE to stop PDCCH monitoring in the first serving cell, and the third condition is a condition for allowing the UE to stop PDCCH monitoring in the second serving cell. When the UE monitors PDCCHs in both the source serving cell and the target serving cell, if the second condition is met, the UE may stop monitoring in the first serving cell; and, if the third condition is met, the UE may stop monitoring in the second serving cell.

Optionally, the second condition being met may include at least one of the following:

PDCCHs are monitored in the second cell;

the UE completes random access in the second cell;

no PDCCH is monitored in the first cell within a fourth duration;

no PDCCH is monitored in the first cell within a second number of continuous time units; and

the numerical value of a second timer is 0, the initial value of the second timer being a second value, the numerical value of the second timer decreasing progressively when no PDCCH is monitored in the first cell within one or more time units, and the numerical value of the second timer being reset as the second value or the second timer being stopped when PDCCHs are monitored in the first cell within one or more time units.

The second timer is used in the first cell. Optionally, the second timer may start to operate after the first duration after receiving the first information (that is, it starts to monitor PDCCHs in the first cell and the second cell). Optionally, the second timer may start to operate when the UE starts to perform information transmission in both the first serving cell and the second serving cell. If the timer is failed (the numerical value is 0), the UE may stop performing information in the first serving cell, for example, stopping PDCCH monitoring. Or, if the IE monitors PDCCHs in the second cell or the UE completes random access in the second cell, PDCCH monitoring in the first cell may be stopped.

Optionally, the third condition being met may include at least one of the following:

PDCCHs are monitored in the first cell, and no PDCCH is monitored in the second cell within a fifth duration;

PDCCHs are monitored in the first cell, and no PDCCH is monitored in the second cell within a third number of continuous time units; and

the numerical value of a third timer is 0, the initial value of the third timer being a third value, the numerical value of the third timer decreasing progressively when no PDCCH is monitored in the second cell within one or more time units, and the numerical value of the third timer being reset as the third value or the third timer being stopped when PDCCHs are monitored in the second cell within one or more time units.

The third timer is used in the second cell. Optionally, the third timer starts to operate after the first duration after receiving the first information.

The second timer or the second timer may be protocoled, or may be provided/configured for the UE by the base station. The optional implementations of the second timer and the third timer may refer to the above description of the first timer.

Based on the optional solution of the present disclosure, the UE may monitor PDCCHs in both the first serving cell and the second serving cell. When the second condition is met, the UE stops monitoring in the first serving cell and monitors PDCCHs in only the second serving cell; or, when the third condition is met, the UE stops monitoring PDCCHs in the second serving cell and monitors PDCCHs in only the first serving cell.

It is to be noted that, in the embodiment of the present disclosure, the first serving cell may include one or more cells; the second serving cell may also include one or more cells; and, when the UE performs PDCCH monitoring in at least one of the first serving cell and the second serving cell, the first condition being met, the second condition being met or the third condition being met may be configured according to the actual application scenario. For example, when the first serving cell or the second serving cell is a plurality of cells, satisfying a condition may be that at least one of the first serving cell or the second serving cell meets the condition.

For example, in one optional solution, before the first duration after receiving the first information, the UE may monitor PDCCHs in at least one of first cells; after the first duration, the UE may perform information transmission in at least one of second cells; and, if the first condition is met, the UE may perform information transmission in at least one of first cells and stop performing information transmission in at least one of second cells. For this solution, the first condition may be that the numerical value of the first timer is 0. If there are a plurality of second serving cells, the plurality of second serving cells may correspond to one first timer, and the value of the first timer decreasing progressively may be that the numerical value of the timer may be reset or the timer is stopped when PDCCHs are monitored in any second serving cell within a time unit. Optionally, each second serving cell may correspond to one timer; the numerical value of the first timer being 0 may be that the numerical value of at least one of the plurality of timers corresponding to the plurality of second serving cells is 0; and, the value of the timer decreasing progressively may be that, for example, when there are two second serving cells which are designated as cell 1 and cell 2, the value of the first timer corresponding to the cell 1 decreases progressively if PDCCHs are monitored in the cell 1 within a time unit, and the value of the first timer corresponding to the cell 2 decreases progressively if PDCCHs are monitored in the cell 2 within a time unit.

For another example, the first condition being met may include no PDCCH being monitored in the second cell within the third duration. When there are a plurality of second serving cells, monitoring PDCCHs in the second cell may be monitoring PDCCHs in at least one of the plurality of second serving cells. No PDCCH being monitored in the second cell within the second duration may mean that no PDCCH is monitored in any one of the plurality of second serving cells. The UE completing random access in the second cell may mean that the UE completes random access in at least one second serving cell, for example, meaning that the UE completes random access in the primary cell.

It should be understood that the situation descried by taking the first condition as an example can also be applied to the situation of the second condition being met or the third condition being met. For example, for the second condition, the second condition being met may also include PDCCHs being monitored in the second cell. Here, PDCCHs being monitored in the second may mean that PDCCHs are monitored in at least one of second serving cells.

In an optional embodiment of the present disclosure, if there are a plurality of first cells and/or there are a plurality of second cells, the monitoring PDCCHs in the first cell and the second cell includes: monitoring PDCCHs in at least one first cell, and monitoring PDCCHs in at least one second cell.

Optionally, if there are a plurality of first cells and/or there are a plurality of second cells, the method may further include:

acquiring second information, the second information being used for indicating some of first cells and/or some of second cells for PDCCH monitoring;

wherein the monitoring PDCCHs in the first cell and the second cell includes: monitoring PDCCHs in the cells indicated by the second information.

That is, if there are a plurality of first cells or second cells, the UE may be informed of performing PDCCH monitoring in which first cell(s) or second cell(s) by the base station, and the indicated cells are at least some of first cells and/or at least some of second cells. The UE may perform PDCCH monitoring in the corresponding cell according to the indication of the base station.

Optionally, the second information may be used for indicating some of first cells and/or some of second cells for PDCCH monitoring. That is, when the UE needs to perform monitoring in some of first cells and/or some of second cells, the base station may inform the UE that PDCCH monitoring is specifically performed on which first cells or second cells. Optionally, the UE has acquired the indication of the base station, the UE may perform PDCCH monitoring in some or all of first cells and/or some or all of second cells according to the protocol.

Optionally, when the UE monitors PDCCHs in some of first cells and/or some of second cells, the method may further include:

after stopping monitoring PDCCHs in the first cells, monitoring PDCCHs in all second cells; and

after stopping monitoring PDCCHs in the second cells, monitoring PDCCHs in all first cells.

The description form of monitoring PDCCHs in all second cells or all first cells will not be limited in the embodiment of the present disclosure. For example, monitoring PDCCHs in all second cells may be described as resuming monitoring PDCCHs in all second cells, or resuming monitoring PDCCHs in other second cells, etc., wherein the other second cells are cells without PDCCH monitoring in all second cells.

In an optional embodiment of the present application, the method may further include:

receiving third information, the third information being used for indicating to monitor PDCCHs in the first cell and the second cell or monitor PDCCHs in the second cell.

That is, the PDCCH monitoring mode of the UE may be indicated by the base station or the DC of the base station. For example, the base station may indicate the UE to perform PDCCH monitoring in the first cell and the second cell or indicate the UE to perform PDCCH monitoring in the second cell when the UE has received the handover command.

The way of transmitting the third information by the base station will not be limited in the embodiment of the present disclosure. Optionally, some or all of the first information, the second information and the third information may be indicated by the base station through a message or signaling, or may be indicated by a plurality of messages or signaling.

Optionally, when the UE monitors PDCCHs in the first cell and the second cell, cell reselection may be triggered when a fourth condition is met. The fourth condition may be protocoled, or may be indicated to the UE by a network entity. Optionally, the fourth condition being met may include at least one of the following:

no PDCCH is monitored within a sixth duration; and

no PDCCH is not monitored within a set number of time units.

In this optional solution, no PDCCH being monitored may mean that no PDCCH is monitored in any cell. Optionally, the sixth duration or the set number of time units may be the sixth duration or the set number of time units after receiving the first information, or may be the sixth duration or the set number of time units starting from other time. For example, the sixth duration may be a duration after the UE starts to monitor PDCCHs in the second cell. For example, when the UE monitors PDCCHs in both the first cell and the second cell, if no PDCCH is monitored within the sixth duration after monitoring, it may be considered that the fourth condition is met.

As an optional solution, the communication method provided by the present disclosure may include the following steps.

The base station or a physical entity of the base station (e.g., a DU of the base station) transmits cell configuration information of each cell in the candidate cell set of the UE to the UE.

The base station transmits a handover comment to the UE, so as to indicate the UE to handover from the first serving cell to the second serving cell.

Upon receiving the handover command, the UE feeds ACK information back to the base station.

The UE may monitor PDCCHs in at least one of the first serving cell and/or the second serving cell.

If the base station has received the ACK information of the handover command, the base station transmits PDCCHs in the second serving cell; and, if the base station has not received the ACK information, the base station may transmit PDCCHs in the first serving cell or transmit PDCCHs in the first serving cell and the second serving cell.

Optionally, if the UE has not received the handover command transmitted by the base station, the UE may monitor PDCCHs in the first serving cell, and the base station still transmits PDCCHs in the first serving cell.

The optional solution provided in the embodiment of the present disclosure has been described above from the perspective of the UE as an executive body. It should be understood that the solution provided in the embodiment of the present disclosure may be realized by the interaction between the UE and the network entity (the base station or the physical entity of the base station). When executed by a network entity, the method provided in the embodiment of the present disclosure may include:

performing information transmission (the performing information transmission includes transmitting PDCCHs) in at least one of the first cell and the second cell; or, performing information transmission in the second cell when a sixth condition is met, and performing information transmission in the first cell or performing information transmission in the first cell and the second cell when the sixth condition is not met.

Optionally, the sixth condition being met includes receiving response information of the UE for the first information.

Optionally, the response information is used for informing the network node device that the UE has received the cell command, wherein the name or description form of the response information will not be limited in the embodiment of the present disclosure. For example, the response information may be acknowledgement information (ACK).

Optionally, the network entity may be a base station, or may be a DU of a base station in a separate wireless network. The method provided in the embodiment of the present disclosure can be applied to a handover scenario between the first serving cell and the second serving cell under the same base station, and can also be applied to a handover scenario between the first serving cell under one base station and the second serving cell under another base station. Optionally, for the handover between serving cells of different base stations, the first base station corresponding to the first serving cell and the second base station may be base stations in a separate system architecture, the centralized unit (CU) of the first base station and the CU of the second base station may be the same CU, and the network entity may be a DU connected to the CU.

Optionally, for the network entity, the method further includes:

transmitting cell configuration information about each of at least two cells, the at least two cells at least including the first cell and the second cell.

Optionally, the performing information transmission in the first cell includes: performing information transmission in the first cell based on the cell configuration information of the first cell.

Optionally, the performing information transmission in the second cell includes: performing information transmission in the second cell based on the cell configuration information of the second cell.

Optionally, when the UE completes random access in the second cell, the network entity performs information transmission in at least one of second cells.

Optionally, the transmitting first information includes: transmitting the first information through an MAC layer signaling or a physical layer signaling.

To better understand the method provided in the embodiment of the present disclosure, the technical solutions provided in the present disclosure will be further described below by some optional examples. The following examples are applied to a situation where the UE receives the handover command indicated by the base station by transmitting an MAC signaling, and can also be applied to a situation where the UE receive the handover command indicated by the base station by transmitting a physical layer signaling. In the following optional examples, the performing information transmission by the UE includes optional solutions of monitoring PDCCHs by the UE, i.e., receiving, by the UE, PDCCHs transmitted by the base station. Similarly, some contents in each example or examples can also be combined when the implementations of the examples are not conflicted.

In an example shown in FIG. 6, the method provided in this example may include: within a first duration (before a moment T) after the UE receives the handover command, monitoring, by the UE, PDCCHs in the first serving cell (at least one of the cells); and, after the first duration, monitoring, by the UE, PDCCHs in the second serving cell.

The time T may be protocoled, or may be configured by the base station. Optionally, if there are a plurality of second serving cells, the values of T corresponding to different serving cells may be the same or different. For example, the T corresponding to the primary cell and the T corresponding to the secondary cell may be different. Optionally, the time T may also be related to the capability information of the UE. For example, the T corresponding to a UE with higher capability is relatively smaller.

In another example, a timer may be configured. If the timer is expired (also called as being failed or run out), the UE switches to a default serving cell (first serving cell) for monitoring PDCCHs. In the schematic diagram shown in FIG. 7, before a certain time (e.g., before the moment T shown in FIG. 7) after the UE receives the handover command, the UE monitors PDCCHs in the first serving cell. From the moment T after the UE receives the handover command, the timer starts to operate, and the UE starts to monitor PDCCHs in the second serving cell and stops monitoring PDCCHs in the first serving cell. Within a time unit (for example, the time unit may be a slot), if a certain condition is not met (for example, the condition is met if PDCCHs are monitored by the UE in a time unit; or otherwise, the condition is not met), the value of the timer decreases by 1, Timer=Timer-1 shown in FIG. 7. Within a time unit, if a certain condition is met, the timer may be reset, Timer reset shown in FIG. 8. Based on this condition, if the value of the timer decreases to 0, the timer is expired, and the UE may return to the first serving cell for monitoring PDCCHs, as shown in FIG. 9. By the method in this example, it can be ensured that the UE returns to the first serving cell for monitoring PDCCHs and the base station also transmits PDCCHs in the first serving cell, when the serving cell where the base station transmits PDCCHs and the serving cell where the UE monitors PDCCHs are different.

In another example, a timer may also be configured. Before a certain time after the UE receives the handover command, the UE monitors PDCCHs in the first serving cell. After the certain time after the UE receives the handover command, the timer starts to operate, and the UE starts to monitor PDCCHs in the second serving cell. Within a time unit, if a certain condition is not met (for example, the condition is met if PDCCHs are monitored by the UE within a time unit; or otherwise, the condition is not met), the value of the timer decreases by 1. If the value of the timer decreases to 0, the timer is expired, and the UE returns to the first serving cell for monitoring PDCCHs. Within a time unit, if the certain condition is met, the timer may be stopped, and the UE may continuously perform monitoring in the second serving cell. That is, when the certain condition is met, the timer may be stopped, and the UE does not return to the source serving cell for monitoring.

Optionally, the timer with an initial value may be configured for the UE by the base station before transmitting the handover command. For example, the timer has an initial value of 2. After the timer starts to operate, if the UE monitors no PDCCH in the second serving cell within two continuous time units, the UE may return to the first serving cell for monitoring. If the UE monitors no PDCCH in a time unit, the timer decrease by 1; and, if PDCCHs are monitored in a next time unit, the numerical value of the timer may be set as 2 or the timer is stopped.

Optionally, the second serving cell may be one cell. Before the numerical value of the timer becomes 0, if PDCCHs are monitored by the UE in the second serving cell, the UE may not return to the first serving cell; or, if the second serving may include at least two cells (which may include a primary cell and a secondary cell), monitoring PDCCHs in the second serving cell by the UE may include monitoring, by the UE, PDCCHs in at least the primary cell of the second serving cell.

In another optional example, as shown in FIG. 10, before the moment T before the UE receives the handover signaling, the UE may monitor PDCCHs in the first serving cell; and, after the moment T after the UE receives the handover signaling, the UE may monitor PDCCHs in both the first serving cell and the second serving cell. After a certain condition is met (for example, the condition is met if PDCCHs are monitored by the UE in the second serving cell, or the condition is met if the UE completes random access in the second serving cell), the UE may monitor PDCCHs in the second serving cell, and the UE stops monitoring PDCCHs in the first serving cell. By using this solution, the UE can be quickly handed over to the target serving cell, and the problem of inconsistency between the serving cell where the UE monitors PDCCHs and the serving cell where the base station transmits PDCCHs can be avoided.

Optionally, before the moment T after the UE receives the handover signaling, when the UE monitors PDCCHs in the first serving cell, the UE may monitor PDCCHs according to the first configuration (e.g., config1) for PDCCH monitoring in the first serving cell. After a certain condition is met, when the UE monitors PDCCHs in the second serving cell, the UE may monitor PDCCHs according to the first configuration for PDCCH monitoring in the second serving cell. After the moment T after the UE receives the first signaling, when the UE monitors PDCCHs in both the first serving cell and the second serving cell, the UE may monitor PDCCHs in the first serving cell according to the second configuration (e.g., config2) for PDCCH monitoring in the first serving cell, and may monitor PDCCHs in the second serving cell according to the second configuration for PDCCH monitoring in the second serving cell.

Corresponding to the communication method provided in the embodiments of the present disclosure, an embodiment of the present disclosure further provides a user equipment, including: at least one transceiver; and, at least one process, which is coupled to the transceiver and configured to execute the method executed by a user equipment provided in any optional embodiment of the present disclosure.

An embodiment of the present disclosure further provides a network entity, including: at least one transceiver; and, at least one processor, which is coupled to the transceiver and configured to execute the method executed by a network entity provided in any optional embodiment of the present disclosure.

Optionally, FIG. 11 shows a schematic structure diagram of an electronic device to which an embodiment of the present disclosure is applicable, which may be implemented as a user equipment or a network entity. As shown in FIG. 11, the electronic device 4000 in FIG. 11 includes a processor 4001 and a memory 4003. Wherein, the processor 4001 communicates with the memory 4003, e.g., via a bus 4002. Optionally, the electronic device 4000 may further include a transceiver 4004. The transceiver 4004 may be configured for data interaction between the electronic device and other electronic devices, for example, transmitting data and/or receiving data, etc. It is to be noted that, in practical applications, the number of the transceiver 4004 is not limited to one, and the structure of the electronic device 4000 does not constitute any limitation to the embodiments of the present disclosure. Optionally, the electronic device may be a first network node, a second network node or a third network node.

The processor 4001 may be a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, a transistor logic device, a hardware component or any combination thereof. The processor can implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the present disclosure. The processor 4001 may also be a combination for realizing computing functions, for example, a combination of one or more microprocessors, a combination of DSPs and microprocessors, etc.

The bus 4002 can include a path for delivering information among the above components. The bus 4002 may be a peripheral component interconnect (PCI) bus, an extended industry standard architecture (EISA) bus, etc. The bus 4002 may be classified into address bus, data bus, control bus, etc. For ease of representation, the bus is represented by only one bold line in FIG. 11, but it does not mean that there is only one bus or one type of buses.

The memory 4003 may be, but not limited to, read only memories (ROMs) or other types of static storage devices capable of storing static information and instructions, random access memories (RAMs) or other types of dynamic storage devices capable of storing information and instructions, or electrically erasable programmable read only memories (EEPROMs), compact disc read only memories (CD-ROMs) or other optical disc storages, optical disc storages (including compact discs, laser discs, optical discs, digital versatile optical discs, Blue-ray discs, etc.), magnetic disc storage mediums or other magnetic storage devices, or any other medium that can be used to carry or store computer programs and can be accessed by a computer.

The memory 4003 is used to store computer programs for executing embodiments of the present disclosure and is controlled for execution by the processor 4001. The processor 4001 is configured to execute the computer program stored in the memory 4003 to implement the steps shown in the foregoing method embodiment.

An embodiment of the present disclosure provides a computer-readable storage medium storing computer programs that, when executed by a processor, can implement the steps and corresponding contents in the above method embodiments.

An embodiment of the present disclosure further provides a computer program product, including computer programs that, when executed by a processor, can implement the steps and corresponding contents in the above method embodiments.

The terms “first”, “second”, “third”, “fourth”, “1”, “2”, etc. (if any) in the specification and claims of the present disclosure and the accompanying drawings are used for distinguishing similar objects, rather than describing a particular order or precedence. It is to be understood that the data so used are interchangeable under appropriate circumstances such that the embodiments of the present disclosure described herein are capable of operation in other sequences than described or illustrated herein.

It should be understood that, although the operation steps are indicated by arrows in the flowcharts of the embodiments of the present disclosure, the implementation order of these steps is not limited to the order indicated by the arrows. Unless otherwise explicitly stated herein, in some implementation scenarios of the embodiments of the present disclosure, the implementation steps in the flowcharts may be executed in other orders as required. In addition, some or all of the steps in each flowchart may include multiple sub-steps or multiple stages based on actual implementation scenarios. Some or all of these sub-steps or phases may be executed at the same moment, and each of these sub-steps or phases may also be executed separately at different moments. The order of execution of these sub-steps or stages can be flexibly configured according to requirements in different scenarios of execution time, and the embodiments of the present disclosure are not limited thereto.

The text and drawings are provided as examples only to help readers understand the present disclosure. They are not intended and should not be interpreted as limiting the scope of the present disclosure in any way. Although certain embodiments and examples have been provided, based on the disclosure herein, it will be apparent to those skilled in the art that changes may be made to the illustrated embodiments and examples without departing from the scope of the present disclosure. Other similar implementation means based on the technical idea of the present disclosure are adopted, and likewise belong to the protection scope of the embodiments of the present disclosure.

Claims

A method executed by a user equipment in a wireless communication system, comprising:

receiving first information, the first information indicating a UE to hand over from a first cell to a second cell; and

monitoring physical downlink control channels (PDCCHs) in the first cell and the second cell, or,

monitoring PDCCHs in the second cell, and monitoring PDCCHs in the first cell and stopping monitoring PDCCHs in the second cell when a first condition is met.
The method according to claim 1, before receiving the first message, further comprising at least one of the following:

receiving cell configuration information about the first cell;

receiving cell configuration information about the second cell; and

receiving cell configuration information about other candidate cells, the other candidate cells being cells other than the first cell and the second cell,

wherein the cell configuration information of any cell comprises first configuration information and second configuration information;

wherein, monitoring PDCCHs in this cell based on the first configuration information of the corresponding cell, during monitoring PDCCHs in the first cell or the second cell; and

monitoring PDCCHs in the first cell based on the second configuration information of the first cell, and monitoring PDCCHs in the second cell based on the second configuration information of the second cell, during monitoring PDCCHs in the first cell and the second cell.
The method according to claim 1, wherein the monitoring PDCCHs in the first cell and the second cell comprises at least one of the following:

monitoring PDCCHs in the first cell and the second cell, and stopping monitoring PDCCHs in the first cell when a second condition is met;

monitoring PDCCHs in the first cell and the second cell, and stopping monitoring PDCCHs in the second cell when a third condition is met; and

monitoring PDCCHs in the first cell and the second cell, and triggering cell reselection when a fourth condition is met,

wherein the second condition being met comprises at least one of the following:

PDCCHs are monitored in the second cell;

the UE completes random access in the second cell; and

the numerical value of a second timer is 0, the initial value of the second timer being a second value, the numerical value of the second timer decreasing progressively when no PDCCH is monitored in the first cell within one or more time units, and the numerical value of the second timer being reset as the second value or the second timer being stopped when PDCCHs are monitored in the first cell within one or more time units, and

wherein the monitoring PDCCHs in the first cell and the second cell comprises:

upon receiving the first information and before a first duration, monitoring PDCCHs in the first cell or the second cell, and after the first duration, monitoring PDCCHs in the first cell and the second cell.
The method according to claim 1, wherein the monitoring PDCCHs in the second cell comprises:

upon receiving the first information and before a second duration, monitoring PDCCHs in the first cell, and after the second duration, monitoring PDCCHs in the second cell and stopping monitoring PDCCHs in the first cell, and

wherein the first condition being met comprises at least one of the following:

the value of a first timer is 0, the initial value of the first timer being a first value, the value of the first timer decreasing progressively when a fifth condition is not met, and the value of the first timer being reset as the first value or the first timer being stopped when the fifth condition is met;

no PDCCH is monitored in the second cell within a third duration; and

no PDCCH is monitored in the second cell within a first number of continuous time units, and

wherein the fifth condition being met comprises at least one of the following:

PDCCHs are monitored in the second cell within one or more time units; and

the UE completes random access in the second cell.
The method according to claim 4, further comprising:

receiving second configuration information, the second configuration information being used for configuring the first timer.
The method according to claim 3, wherein the third condition being met comprises at least one of the following:

PDCCHs are monitored in the first cell, and no PDCCH is monitored in the second cell within a fifth duration;

PDCCHs are monitored in the first cell, and no PDCCH is monitored in the second cell within a third number of continuous time units; and

the numerical value of a third timer is 0, the initial value of the third timer being a third value, the numerical value of the third timer decreasing progressively when no PDCCH is monitored in the second cell within one or more time units, and the numerical value of the third timer being reset as the third value or the third timer being stopped when PDCCHs are monitored in the second cell within one or more time units,

wherein the receiving first information comprises:

receiving the first information through a medium access control (MAC) layer signaling or a physical layer signaling, and

wherein, if there are a plurality of first cells, and/or there are a plurality of second cells,

the monitoring PDCCHs in the first cell and the second cell comprises:

monitoring PDCCHs in at least one first cell and monitoring PDCCHs in at least one second cell.
The method according to claim 6, further comprising:

acquiring second information, the second information being used for indicating some of first cells and/or some of second cells for PDCCH monitoring;

the monitoring PDCCHs in the first cell and the second cell comprises monitoring PDCCHs in the cells indicated by the second information,

after stopping monitoring PDCCHs in the first cells, monitoring PDCCHs in all second cells; or

after stopping monitoring PDCCHs in the second cells, monitoring PDCCHs in all first cells, and

receiving third information, the third information being used for indicating to monitor PDCCHs in the first cell and the second cell or monitor PDCCHs in the second cell.
A method executed by a network node device in a wireless communication system, comprising:

transmitting first information, the first information indicating a UE to hand over from a first cell to a second cell;

transmitting PDCCHs in the first cell and the second cell; or

transmitting PDCCHs in the second cell when a six condition is met, and transmitting PDCCHs in the first cell when the sixth condition is not met; and

receiving response information of the UE to the first information.
A user equipment in a wireless communication system, the user equipment comprising:

a transceiver; and

a controller coupled with the transceiver and configured to:

receive first information, the first information indicating a UE to hand over from a first cell to a second cell; and

monitor physical downlink control channels (PDCCHs) in the first cell and the second cell, or,

monitor PDCCHs in the second cell, and monitor PDCCHs in the first cell and stop monitor PDCCHs in the second cell when a first condition is met.
The user equipment according to claim 9, wherein the controller is further configured to:

receive cell configuration information about the first cell;

receive cell configuration information about the second cell; and

receive cell configuration information about other candidate cells, the other candidate cells being cells other than the first cell and the second cell,

wherein the cell configuration information of any cell comprises first configuration information and second configuration information;

wherein, monitor PDCCHs in this cell based on the first configuration information of the corresponding cell, during monitoring PDCCHs in the first cell or the second cell; and

monitor PDCCHs in the first cell based on the second configuration information of the first cell, and monitor PDCCHs in the second cell based on the second configuration information of the second cell, during monitor PDCCHs in the first cell and the second cell,wherein the monitor PDCCHs in the first cell and the second cell comprises at least one of the following:

monitor PDCCHs in the first cell and the second cell, and stop monitor PDCCHs in the first cell when a second condition is met;

monitor PDCCHs in the first cell and the second cell, and stop monitor PDCCHs in the second cell when a third condition is met; and

monitor PDCCHs in the first cell and the second cell, and trigger cell reselection when a fourth condition is met,

wherein the second condition being met comprises at least one of the following:

PDCCHs are monitored in the second cell;

the UE completes random access in the second cell; and

the numerical value of a second timer is 0, the initial value of the second timer being a second value, the numerical value of the second timer decreasing progressively when no PDCCH is monitored in the first cell within one or more time units, and the numerical value of the second timer being reset as the second value or the second timer being stopped when PDCCHs are monitored in the first cell within one or more time units, and

wherein the monitoring PDCCHs in the first cell and the second cell comprises:

upon receive the first information and before a first duration, monitor PDCCHs in the first cell or the second cell, and after the first duration, monitor PDCCHs in the first cell and the second cell.
The user equipment according to claim 9,

wherein the controller is further configured to:

upon receive the first information and before a second duration, monitor PDCCHs in the first cell, and after the second duration, monitor PDCCHs in the second cell and stop monitor PDCCHs in the first cell, and

wherein the first condition being met comprises at least one of the following:

the value of a first timer is 0, the initial value of the first timer being a first value, the value of the first timer decreasing progressively when a fifth condition is not met, and the value of the first timer being reset as the first value or the first timer being stopped when the fifth condition is met;

no PDCCH is monitored in the second cell within a third duration; and

no PDCCH is monitored in the second cell within a first number of continuous time units, and

wherein the fifth condition being met comprises at least one of the following:

PDCCHs are monitored in the second cell within one or more time units; and

the UE completes random access in the second cell.
The user equipment according to claim 11,

wherein the controller is further configured to:

receive second configuration information, the second configuration information being used for configuring the first timer.
The user equipment according to claim 10, wherein the third condition being met comprises at least one of the following:

PDCCHs are monitored in the first cell, and no PDCCH is monitored in the second cell within a fifth duration;

PDCCHs are monitored in the first cell, and no PDCCH is monitored in the second cell within a third number of continuous time units; and

the numerical value of a third timer is 0, the initial value of the third timer being a third value, the numerical value of the third timer decreasing progressively when no PDCCH is monitored in the second cell within one or more time units, and the numerical value of the third timer being reset as the third value or the third timer being stopped when PDCCHs are monitored in the second cell within one or more time units,

wherein the receiving first information comprises:

receiv the first information through a medium access control (MAC) layer signaling or a physical layer signaling, and

wherein, if there are a plurality of first cells, and/or there are a plurality of second cells,

the monitor PDCCHs in the first cell and the second cell comprises:

monitor PDCCHs in at least one first cell and monitoring PDCCHs in at least one second cell.
The user equipment according to claim 13,

wherein the controller is further configured to:

acquire second information, the second information being used for indicating some of first cells and/or some of second cells for PDCCH monitor;

the monitor PDCCHs in the first cell and the second cell comprises monitor PDCCHs in the cells indicated by the second information,

after stop monitor PDCCHs in the first cells, monitoring PDCCHs in all second cells; or

after stop monitor PDCCHs in the second cells, monitoring PDCCHs in all first cells, and

receive third information, the third information being used for indicating to monitor PDCCHs in the first cell and the second cell or monitor PDCCHs in the second cell.
A network node device in a wireless communication system, the network node comprising:

a transceiver; and

a controller coupled with the transceiver and configured to:

transmit first information, the first information indicating a UE to hand over from a first cell to a second cell;

transmit PDCCHs in the first cell and the second cell; or

transmit PDCCHs in the second cell when a six condition is met, and transmit PDCCHs in the first cell when the sixth condition is not met; and

receive response information of the UE to the first information.