Apparatus and method for PDCCH command RACH for mobility

Abstract

A method for user equipment (UE) to command a random access channel (RACH) for a physical downlink control channel (PDCCH) for mobility comprises the following steps: receiving configuration of a first candidate cell list from a base station; receiving RACH (Random Access Channel) configuration for each non-serving cell contained in the first candidate cell list from the base station; and receiving a first control signaling from the base station, the first control signaling instructing the UE to send a physical random access channel (PRACH) to a first non-serving cell included in the first candidate cell list.

Description

Technical Field

[0001] The present disclosure relates to the field of communication systems, and more particularly to an apparatus and method for a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility. Background Art

[0002] The current physical downlink control channel (PDCCH) command physical random access channel (PRACH) cannot trigger the user equipment (UE) to send the PRACH preamble to a non-serving cell. Therefore, when the UE is connected to the serving cell, the UE cannot send PRACH to the non-serving cell. As a result, when the UE is instructed to switch to a non-serving cell, the UE needs to perform a random access procedure to the cell, and the delay of switching cells increases.

[0003] Therefore, there is a need for an apparatus and method for a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility. Summary of the invention

[0004] The purpose of the present disclosure is to propose an apparatus and method for a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility, which can solve the problems in the prior art and other problems, and / or reduce the delay of inter-cell mobility.

[0005] In a first aspect of the present disclosure, a method for a user equipment (UE) to perform a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility includes: receiving a configuration of a first candidate cell list from a base station, receiving a RACH configuration for each non-serving cell included in the first candidate cell list from the base station, and receiving a first control signaling from the base station, wherein the first control signaling instructs the UE to send a physical random access channel (PRACH) to a first non-serving cell included in the first candidate cell list.

[0006] In a second aspect of the present disclosure, a UE includes a receiver configured to: receive a configuration of a first candidate cell list from a base station, receive a RACH configuration for each non-serving cell included in the first candidate cell list from the base station, and receive a first control signaling from the base station, wherein the first control signaling instructs the UE to send a physical random access channel (PRACH) to a first non-serving cell included in the first candidate cell list.

[0007] In a third aspect of the present disclosure, a UE includes a memory, a transceiver, and a processor coupled to the memory and the transceiver. The UE is configured to execute the above method.

[0008] In a fourth aspect of the present disclosure, a method for a base station to perform a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility includes: sending a configuration of a first candidate cell list to a user equipment (UE); sending a RACH configuration for each non-service cell included in the first candidate cell list to the UE; and sending a first control signaling to the UE, wherein the first control signaling instructs the UE to send a physical random access channel (PRACH) to a first non-service cell included in the first candidate cell list.

[0009] In a fifth aspect of the present disclosure, a base station includes a transmitter configured to send a configuration of a first candidate cell list to a user equipment (UE), send a RACH configuration for each non-serving cell included in the first candidate cell list to the UE, and send a first control signaling to the UE, wherein the first control signaling instructs the UE to send a physical random access channel (PRACH) to a first non-serving cell included in the first candidate cell list.

[0010] In a sixth aspect of the present disclosure, a base station includes a memory, a transceiver, and a processor coupled to the memory and the transceiver. The base station is configured to provide the above method.

[0011] In a seventh aspect of the present disclosure, a non-transitory machine-readable storage medium stores instructions on the non-transitory machine-readable storage medium, which, when executed by a computer, causes the computer to execute the above method.

[0012] In an eighth aspect of the present disclosure, a chip includes a processor, wherein the processor is configured to call and run a computer program stored in a memory so that a device equipped with the chip executes the above method.

[0013] In a ninth aspect of the present disclosure, a computer-readable storage medium is provided, in which a computer program is stored, so that a computer executes the above method.

[0014] In a tenth aspect of the present disclosure, a computer program product includes a computer program, and the computer program enables a computer to execute the above method.

[0015] In an eleventh aspect of the present disclosure, a computer program enables a computer to execute the above method. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments or related technologies of the present disclosure, the following briefly introduces the drawings to be described in the embodiments. Obviously, the drawings are only some embodiments of the present disclosure, and ordinary technicians in this field can obtain other drawings based on these drawings without any prerequisites.

[0017] Figure 1 is a block diagram of one or more user equipments (UEs) and a base station communicating in a communication network system according to an embodiment of the present disclosure.

[0018] Figure 2 is a block diagram of one or more user equipments (UEs) and a base station communicating in a communication network system according to an embodiment of the present disclosure.

[0019] Figure 3 is a block diagram of a UE according to an embodiment of the present disclosure.

[0020] Figure 4 is a block diagram of a UE according to an embodiment of the present disclosure.

[0021] Figure 5 is a flowchart illustrating a method of a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility performed by a UE according to an embodiment of the present disclosure.

[0022] Figure 6 is a block diagram of a base station according to an embodiment of the present disclosure.

[0023] Figure 7 is a block diagram of a base station according to an embodiment of the present disclosure.

[0024] Figure 8 is a flowchart illustrating a method of a physical downlink control channel (PDCCH) commanding a random access channel (RACH) for mobility, performed by a base station according to an embodiment of the present disclosure.

[0025] Fig. 9 is a flow chart illustrating a method of a physical downlink control channel (PDCCH) commanding a random access channel (RACH) for mobility according to an embodiment of the present disclosure.

[0026] Fig.10 is a block diagram of an example of a computing device according to an embodiment of the present disclosure.

[0027] Fig.11 is a block diagram of a communication system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0028] The following describes the embodiments of the present disclosure in detail in terms of technical content, structural features, achieved goals and effects with reference to the accompanying drawings. Specifically, the terms in the embodiments of the present disclosure are only for the purpose of describing specific embodiments and do not limit the present disclosure.

[0029] The technical solutions of the embodiments of the present disclosure can be applied to various communication systems, such as: global system of mobile communication (GSM) system, code division multiple access (CDMA) system, wideband code division multiple access (WCDMA) system, general packet radio service (GPRS), long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, enhanced long term evolution (LTE-A) system, new radio (NR) system, NR system evolution system, LTE-based access to unlicensed spectrum (LTE-U) system, NR-based access to unlicensed spectrum (LTE-U) system, universal mobile telecommunication system (UMTS), global interoperability for microwave access (global interoperability for microwave access) system. access, WiMAX) communication system, wireless local area network (wireless local area network, WLAN), wireless fidelity (wireless fidelity, Wi-Fi), the future fifth generation (5th generation, 5G) system (also known as the new air interface (NR) system) or other communication systems.

[0030] Optionally, the base station mentioned in the embodiments of the present application can provide communication coverage for a specific geographical area and can communicate with a user equipment (UE) located in the coverage area. Optionally, the base station can be a gNB, a base transceiver station (BTS) in a GSM or CDMA system, or a NodeB (NB) in a WCDMA system, or an evolved NodeB (eNB or eNodeB) in an LTE system, or a wireless controller in a cloud radio access network (CRAN).

[0031] User equipment (UE) may refer to an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, or a user device. An access terminal may be a cellular wireless phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication capabilities, a computing device, other processing devices coupled to a wireless modem, an in-vehicle device, a wearable device, a terminal device in a future 5G network, a terminal device in a future evolved PLMN (Public Land Mobile Network), etc.

[0032] Optionally, the communication system in the embodiments of the present application may be applied to an unlicensed spectrum, wherein the unlicensed spectrum may also be considered as a shared spectrum; or, the communication system in the embodiments of the present application may also be applied to an authorized spectrum, wherein the authorized spectrum may also be considered as an unshared spectrum.

[0033] New Radio (NR) / Fifth Generation (5G) systems support physical downlink control channel (PDCCH) commanding physical random access channel (PRACH) transmissions. PDCCH commanding PRACH transmissions is a mechanism by which a base station, such as a gNB (next generation NodeB), can command a user equipment (UE) to initiate a PRACH transmission. An example use case for this mechanism is when the gNB finds that the timing between the gNB and the UE needs further improvement, the gNB can command the UE to send PRACH, and then the gNB can measure the uplink timing. In NR / 5G systems, the gNB uses downlink control information (DCI) format 0_1 ​​to trigger PDCCH commanding PRACH transmissions. Figure 1 The basic process 100 shown in the figure includes: operation 102, the gNB provides the configuration of PRACH to the UE; operation 104, the gNB sends DCI format 1_0 to trigger PRACH transmission; operation 106, the UE decodes the DCI format 1_0 and sends the PRACH preamble code according to the indication information indicated in the DCI format 1_0; operation 108, the gNB detects the PRACH preamble code; and operation 110, the gNB sends a PRACH response to the UE.

[0034] like Figure 1 As shown, the gNB first provides the configuration of PRACH to the UE. When the gNB needs PRACH, for example to improve timing, the gNB can send DCI format 1_0 to trigger the UE to send PRACH. When the UE receives DCI format 1_0 for the PDCCH command PRACH, the UE selects the PRACH preamble according to the configuration provided by the gNB, and then sends the selected PRACH preamble in the corresponding PRACH resource. The gNB then detects the PRACH preamble, and thereafter, the gNB sends a response to the UE.

[0035] DCI format 1_0 used by the gNB to trigger PRACH transmission has the following fields:

[0036] Random Access Preamble Index: It is used to indicate the index of the PRACH preamble selected by the UE for transmission.

[0037] Uplink (UL) / supplementary uplink (SUL) indicator: This field is used to indicate which uplink carrier in the cell is used to send the PRACH.

[0038] Synchronization signal / physical broadcast channel (SS / PBCH) index: This field indicates the SS / PBCH that is used to determine the RACH timing for PRACH transmission.

[0039] PRACH Mask Index: This field indicates the RACH opportunity associated with the SS / PBCH indicated by "SS / PBCH Index" for PRACH transmission.

[0040] In NR / 5G systems, the PDCCH command PRACH can be used to trigger a contention-based random access procedure or a non-contention-based random access procedure.

[0041] The current physical downlink control channel (PDCCH) command physical random access channel (PRACH) cannot trigger the user equipment (UE) to send the PRACH preamble to a non-serving cell. Therefore, when the UE is connected to the serving cell, the UE cannot send PRACH to the non-serving cell. As a result, when the UE is instructed to switch to a non-serving cell, the UE needs to perform a random access procedure to the cell, and the delay of switching cells increases.

[0042] Therefore, some embodiments of the present disclosure propose an apparatus and method for a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility, which can solve the problems in the prior art and other problems, and / or reduce the delay of inter-cell mobility.

[0043] Figure 2 It is shown that, in some embodiments, one or more user equipments (UE) 10 and base stations (e.g., next generation NodeB (gNB) or eNB) 20 communicating in a communication network system 30 (e.g., NR system) according to an embodiment of the present disclosure are provided. The communication network system 30 includes one or more UEs 10 and base stations 20. One or more UEs 10 may include a memory 12, a transceiver 13, and a processor 11 coupled to the memory 12 and the transceiver 13. The base station 20 may include a memory 22, a transceiver 23, and a processor 21 coupled to the memory 22 and the transceiver 23. The processor 11 or 21 may be configured to implement the proposed functions, processes and / or methods described in this specification. The layers of the radio interface protocol may be implemented in the processor 11 or 21. The memory 12 or 22 is operatively coupled to the processor 11 or 21 and stores various information to operate the processor 11 or 21. The transceiver 13 or 23 is operatively coupled to the processor 11 or 21 , and the transceiver 13 or 23 transmits and / or receives wireless signals.

[0044] The processor 11 or 21 may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits and / or data processing devices. The memory 12 or 22 may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium and / or other storage devices. The transceiver 13 or 23 may include a baseband circuit for processing radio frequency signals. When the embodiment is implemented in software, the techniques described herein may be implemented using modules (e.g., programs, functions, etc.) that perform the functions described herein. These modules may be stored in the memory 12 or 22 and executed by the processor 11 or 21. The memory 12 or 22 may be implemented within the processor 11 or 21, or implemented outside the processor 11 or 21, in which case the memory 12 or 22 may be communicatively coupled to the processor 11 or 21 via various means known in the art.

[0045] In some embodiments, the transceiver 13 is configured to receive a configuration of a first candidate cell list from the base station 20, receive a RACH configuration for each non-serving cell included in the first candidate cell list from the base station 20, and receive a first control signaling from the base station 20, wherein the first control signaling instructs the UE 10 to send a physical random access channel (PRACH) to the first non-serving cell included in the first candidate cell list. This can solve the problems in the prior art and other problems, and / or reduce the delay of inter-cell mobility.

[0046] In some embodiments, the transceiver 23 is configured to send a configuration of the first candidate cell list to the UE 10, send a RACH configuration for each non-serving cell included in the first candidate cell list to the UE 10, and send a first control signaling to the UE 10, wherein the first control signaling instructs the UE 10 to send a physical random access channel (PRACH) to the first non-serving cell included in the first candidate cell list. This can solve the problems in the prior art and other problems, and / or reduce the delay of inter-cell mobility.

[0047] Figure 3An example of a UE 300 according to an embodiment of the present application is shown. The UE 300 is configured to implement some embodiments of the present disclosure. Any appropriately configured hardware and / or software may be used to implement some embodiments of the present disclosure in the UE 300. The UE 300 includes a receiver 301 configured to receive a configuration of a first candidate cell list from a base station, receive a RACH configuration for each non-serving cell included in the first candidate cell list from the base station, and receive a first control signaling from the base station, wherein the first control signaling instructs the UE to send a physical random access channel (PRACH) to a first non-serving cell included in the first candidate cell list. This can solve the problems in the prior art and other problems, and / or reduce the delay of inter-cell mobility.

[0048] Figure 4 An example of a UE 400 according to an embodiment of the present disclosure is shown. The UE 400 is configured to implement some embodiments of the present disclosure. Some embodiments of the present disclosure may be implemented in the UE 400 using any suitably configured hardware and / or software. The UE 400 may include a memory 401, a transceiver 402, and a processor 403 coupled to the memory 401 and the transceiver 402. The processor 403 may be configured to implement the proposed functions, processes and / or methods described in this specification. The layers of the wireless interface protocol may be implemented in the processor 403. The memory 401 is operatively coupled to the processor 303 and stores various information to operate the processor 403. The transceiver 402 is operatively coupled to the processor 403, and the transceiver 402 sends and / or receives wireless signals. The processor 403 may include an application specific integrated circuit (ASIC), other chipsets, logic circuits and / or data processing devices. The memory 401 may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium, and / or other storage devices. The transceiver 402 may include a baseband circuit for processing radio frequency signals. When the embodiment is implemented in software, the techniques described herein may be implemented using modules (e.g., programs, functions, etc.) that perform the functions described herein. These modules may be stored in the memory 401 and executed by the processor 403. The memory 401 may be implemented within the processor 403, or implemented outside the processor 403, in which case the memory 401 may be communicatively coupled to the processor 403 via various means known in the art.

[0049] In some embodiments, the transceiver 402 is configured to receive a configuration of a first candidate cell list from a base station, receive a RACH configuration for each non-serving cell included in the first candidate cell list from the base station, and receive a first control signaling from the base station, wherein the first control signaling instructs the UE to send a physical random access channel (PRACH) to the first non-serving cell included in the first candidate cell list. This can solve the problems in the prior art and other problems, and / or reduce the delay of inter-cell mobility.

[0050] Figure 5 It is an example of a method 500 of a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility performed by a UE according to an embodiment of the present disclosure. The method 500 of a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility performed by a UE is configured to implement some embodiments of the present disclosure. Any suitably configured hardware and / or software may be used to implement some embodiments of the present disclosure in the method 500 of a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility performed by a UE. In some embodiments, the method 500 of a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility performed by a UE includes: operation 502, receiving a configuration of a first candidate cell list from a base station; operation 504, receiving a RACH configuration for each non-serving cell included in the first candidate cell list from the base station; and operation 406, receiving a first control signaling from the base station, wherein the first control signaling instructs the UE to send a physical random access channel (PRACH) to a first non-serving cell included in the first candidate cell list. This may solve problems in the prior art and other problems, and / or reduce delays in inter-cell mobility.

[0051] In some embodiments, the method further comprises: sending a PRACH preamble according to the configuration of the first candidate cell list, the RACH configuration and the first control signaling. In some embodiments, the UE is configured to send a PRACH preamble to the first non-serving cell for the first non-serving cell to measure the uplink timing of the UE. In some embodiments, the method further comprises: receiving a RACH response from a base station. In some embodiments, the configuration of the first candidate cell list and / or the RACH configuration is sent in a radio resource control (RRC). In some embodiments, the first control signaling comprises a media access control (MAC) control element (CE) or downlink control information (DCI). In some embodiments, the DCI is a DCI format X or a DCI format 1_0.

[0052] In some embodiments, the first control signaling indicates one or more of the following information: an indicator of a first non-serving cell to which a UE in a first candidate cell list is instructed to send a PRACH preamble, an indicator of a synchronization signal / physical broadcast channel (SS / PBCH) of the cell, an indicator of a random access preamble index, an indicator of a PRACH mask index, and / or an indicator of whether the UE expects a random access response (RAR) message.

[0053] Figure 6 An example of a base station 600 according to an embodiment of the present application is shown. The base station 600 is configured to implement some embodiments of the present disclosure. Some embodiments of the present disclosure may be implemented in the base station 600 using any appropriately configured hardware and / or software. The base station 600 includes a transmitter 601 configured to send a configuration of a first candidate cell list to a user equipment (UE), send a RACH configuration for each non-serving cell included in the first candidate cell list to the UE, and send a first control signaling to the UE, wherein the first control signaling instructs the UE to send a physical random access channel (PRACH) to a first non-serving cell included in the first candidate cell list.

[0054] Figure 7An example of a base station 700 according to an embodiment of the present disclosure is shown. The base station 700 is configured to implement some embodiments of the present disclosure. Some embodiments of the present disclosure may be implemented in the base station 700 using any suitably configured hardware and / or software. The base station 700 may include a memory 701, a transceiver 702, and a processor 703 coupled to the memory 701 and the transceiver 702. The processor 703 may be configured to implement the proposed functions, processes and / or methods described in this specification. The layers of the wireless interface protocol may be implemented in the processor 703. The memory 701 is operatively coupled to the processor 703 and stores various information to operate the processor 703. The transceiver 702 is operatively coupled to the processor 703, and the transceiver 702 sends and / or receives wireless signals. The processor 703 may include an application specific integrated circuit (ASIC), other chipsets, logic circuits and / or data processing devices. The memory 701 may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium, and / or other storage devices. The transceiver 702 may include a baseband circuit for processing radio frequency signals. When the embodiment is implemented in software, the techniques described herein may be implemented using modules (e.g., programs, and functions, etc.) that perform the functions described herein. These modules may be stored in the memory 701 and executed by the processor 703. The memory 701 may be implemented within the processor 703, or implemented outside the processor 703, in which case the memory 701 may be communicatively coupled to the processor 703 via various means known in the art.

[0055] In some embodiments, the transceiver 702 is configured to send a configuration of a first candidate cell list to a user equipment (UE), send a RACH configuration for each non-serving cell included in the first candidate cell list to the UE, and send a first control signaling to the UE, wherein the first control signaling instructs the UE to send a physical random access channel (PRACH) to the first non-serving cell included in the first candidate cell list. This can solve the problems in the prior art and other problems, and / or reduce the delay of inter-cell mobility.

[0056] Figure 8It is an example of a method 800 of a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility performed by a base station according to an embodiment of the present disclosure. The method 800 of a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility performed by a base station is configured to implement some embodiments of the present disclosure. Any suitably configured hardware and / or software may be used to implement some embodiments of the present disclosure in a method 800 of a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility performed by a base station. In some embodiments, the method 800 of a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility performed by a base station includes: operation 802, sending a configuration of a first candidate cell list to a user equipment (UE); operation 804, sending a RACH configuration for each non-serving cell included in the first candidate cell list to the UE; and operation 806, sending a first control signaling to the UE, wherein the first control signaling instructs the UE to send a physical random access channel (PRACH) to a first non-serving cell included in the first candidate cell list. This may solve problems in the prior art and other problems, and / or reduce delays in inter-cell mobility.

[0057] In some embodiments, the method further includes: receiving a PRACH preamble from the UE according to the following items: a configuration of a first candidate cell list, a RACH configuration, and a first control signaling. In some embodiments, the base station is configured in the first non-serving cell to receive a PRACH preamble to measure the uplink timing of the UE. In some embodiments, the method further includes: sending a RACH response to the UE. In some embodiments, the configuration of the first candidate cell list and / or the RACH configuration are sent in a radio resource control (RRC). In some embodiments, the first control signaling includes a media access control (MAC) control element (CE) or downlink control information (DCI). In some embodiments, the DCI is a DCI format X or a DCI format 1_0.

[0058] In some embodiments, the first control signaling indicates one or more of the following information: an indicator of a first non-serving cell to which a base station in the first candidate cell list instructs the UE to send a PRACH preamble, an indicator of the cell's synchronization signal / physical broadcast channel (SS / PBCH), an indicator of a random access preamble index, an indicator of a PRACH mask index, and / or an indicator of whether the UE expects a random access response (RAR) message.

[0059] Exemplary technical solutions:

[0060] In some embodiments, the serving gNB may provide a first candidate cell list to the UE, wherein the candidate cell list (a list of one or more candidate cells) may be a list of (one or more) physical cell IDs (identities) indicating one or more non-serving cells that are candidates for mobility. The gNB may also provide a RACH configuration for each cell included in the first candidate cell list. In other words, for a cell included in the first candidate cell list (one or more candidate cells), there is a configuration for RACH transmission. The gNB may then instruct the UE to send a PRACH to a first non-serving cell included in the first candidate cell list (one or more candidate cells). The gNB may provide the UE with a configuration of the PRACH for one or more non-serving cells. The gNB may send first control signaling (e.g., a MAC CE, or, for example, a DCI) to instruct the UE to send a PRACH to the first non-serving cell. The first control signaling may indicate one or more of the following information:

[0061] An indicator for indicating a first non-serving cell to which the UE in the first candidate cell list is instructed to send a PRACH preamble.

[0062] Indicator of the SS / PBCH of the cell. This field may indicate the SS / PBCH of the non-serving cell. The UE may be requested to use the indicated SS / PBCH to determine the RACH timing for PRACH transmission.

[0063] Indicator of random access preamble index. This field may indicate a PRACH preamble that the UE uses for transmission.

[0064] Indicator of PRACH mask index. This field can be used to indicate the RACH opportunity used for PRACH transmission.

[0065] An indicator used to indicate whether the UE expects a RAR (Random Access Response) message.

[0066] In some embodiments, when the first control signaling is received, the UE may be requested to send a PRACH preamble to the first non-serving cell in a determined PRACH opportunity. In one example, based on an indicated SS / PBCH of the first non-serving cell, the UE may be indicated a RACH opportunity for PRACH transmission. The UE may be requested to determine an uplink transmission configuration for sending the PRACH preamble based on the indicated SS / PBCH of the first non-serving cell, wherein the uplink transmission configuration may include a spatial transmit filter and / or uplink transmit power. In some embodiments, when a PRACH preamble transmission is received from the UE, the gNB may determine a timing advance value for uplink transmission to the first non-serving cell. The gNB may indicate to the UE the timing advance for uplink transmission to the first non-serving cell.

[0067] Fig. 9 A method for a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility according to an embodiment of the present disclosure is shown. In some embodiments, a method 900 for a physical downlink control channel (PDCCH) command random access channel (RACH) for mobility shows a process of RACH to a non-serving cell, and includes: operation 902, the gNB provides a configuration of a first candidate cell list to the UE in the RRC; operation 904, for each non-serving cell included in the first candidate cell list, the gNB provides the RACH configuration to the UE in the RRC; operation 906, the gNB sends a first control signaling to the UE to instruct the UE to send a PRACH to the first non-serving cell included in the first candidate cell list; operation 908, the UE sends a PRACH preamble according to the configuration information provided in the RRC and the information indicated in the first control signaling; operation 910, the first non-serving cell receives the PRACH preamble sent by the UE and measures the uplink timing of the UE; operation 912, the gNB may send a RACH response to the UE, and the UE receives the RACH response from the gNB. This may solve problems in the prior art and other problems, and / or reduce delays in inter-cell mobility.

[0068] In some examples, the gNB may use a DCI format X to trigger the UE to send a PRACH preamble to a non-serving cell. DCI format X may include one or more of the following bit fields:

[0069] Indicator for indicating a cell in the first candidate cell list. This field may indicate a non-serving cell to which the UE in the first candidate cell list is instructed to send the PRACH preamble. In one example, if the UE is not configured with L1 / L2 triggered mobility, the size of this field may be zero. In one example, if the UE is configured with L1 / L2 triggered mobility, the size of this field may be N bits. In one example, if the UE is provided with a first candidate cell list, the size of this field may be N bits and the size is Wherein, L is the number of cells configured in the first candidate cell list.

[0070] Indicator of the SS / PBCH of the cell. This field may indicate the SS / PBCH of the non-serving cell. The UE may be requested to use the indicated SS / PBCH to determine the RACH timing for PRACH transmission.

[0071] Indicator of random access preamble index. This field may indicate a PRACH preamble that the UE uses for transmission.

[0072] Indicator of PRACH mask index. This field can be used to indicate the RACH opportunity used for PRACH transmission.

[0073] Indicator used to tell the UE whether to expect a RAR message after sending the PRACH preamble.

[0074] In one example, the gNB may send a DCI format 1_0 to trigger the UE to send a PRACH transmission. Such a DCI format 1_0 may contain the following fields:

[0075] Random Access Preamble Index: In one example, it can be 6 bits. It can indicate a RACH preamble index.

[0076] UL / SUL indicator: In one example, this field may be 1 bit. This field indicates which UL carrier in the cell is used to transmit the PRACH.

[0077] SS / PBCH Index: This field may be 6 bits. This field may indicate one SS / PBCH of the serving cell indicated by the "Indicator of Physical Cell ID" field, which is used to determine the RACH opportunity for PRACH transmission.

[0078] PRACH Mask Index: This field may be 4 bits. This field may indicate the RACH opportunity associated with the SS / PBCH indicated by "SS / PBCH Index" for PRACH transmission.

[0079] Indicator of a physical cell ID (PCI): This field indicates which serving cell is used to send the PRACH. In one example, for a UE not configured with L1 / L2 triggered mobility, this field has 0 bits. In one example, for a UE not configured with a first candidate cell list for L1 / L2 triggered mobility, this field has 0 bits. In one example, for a UE configured with a first candidate cell list, this field has bits, where the first candidate cell list contains L candidate cells. In one example, a DCI code point of this field may indicate that the UE sends a PRACH preamble to the serving cell. For example, a DCI code point of all 0s indicates that the UE sends a PRACH preamble to the serving cell, and a DCI code point of 001 indicates that the UE sends a PRACH preamble to the non-serving cell of the first entry in the first candidate cell list.

[0080] Indicator of a RAR: This field indicates whether the UE expects a RAR message after sending the PRACH preamble. In one example, for a UE that is not configured with a candidate cell list for L1 / L2 triggered mobility, this field has 0 bits. In one example, for a UE that is not configured with a candidate cell list for L1 / L2 triggered mobility, this field has 0 bits. In one example, for a UE that is configured with a candidate cell list for L1 / L2 triggered mobility, this field has 1 bit.

[0081] In some embodiments, the gNB may provide a first candidate cell list for L1 / L2 triggered mobility, and the gNB may provide a RACH configuration for each non-serving cell included in the first candidate cell list. The gNB provides the RACH configuration for the serving cell. The gNB may send a DCI format 1_0 to trigger the UE to send a PRACH preamble to a non-serving cell in the first candidate cell list or to a serving cell. When the UE receives a DCI format 1_0 triggering a PRACH transmission, the UE shall send a PRACH preamble according to the indication in the DCI format 1_0 and the RACH configuration of the non-serving cell or serving cell indicated by the DCI format 1_0.

[0082] In one example, the UE determines the transmit power of the PRACH preamble transmission according to the SSB of the indicated serving cell or non-serving cell indicated by DCI format 1_0. In one example, the UE determines the uplink transmission timing of the PRACH preamble transmission according to the DL (downlink) timing of the serving cell or non-serving cell indicated by DCI format 1_0. In one example, DCI format 1_0 can be used to indicate whether the UE expects a RAR message after sending a PRACH preamble to a non-serving cell. A DCI field in DCI format 1_0 can be used to indicate whether the UE expects a RAR message after sending a PRACH preamble according to the indication in DCI format 1_0.

[0083] In one example, whether the UE expects a RAR message after sending a PRACH preamble to a non-serving cell can be configured through RRC. For example, the gNB can provide an indicator for the first non-serving cell in the first candidate cell list, and the indicator can indicate whether the UE expects a RAR message after sending a PRACH preamble to the first non-serving cell. For example, the gNB can provide an indicator in the RRC indicating whether the UE expects a RAR message after sending a PRACH preamble to a non-serving cell in the first candidate cell list. Some of the proposed embodiments can reduce the delay of inter-cell mobility. Before switching to a target cell (which is a non-serving cell), the serving cell gNB can trigger the UE to send a PRACH to the target cell so that the UE can obtain uplink timing to the non-serving cell before switching to the target cell.

[0084] The commercial benefits of some embodiments are as follows. 1. Solve problems in the prior art and other problems. 2. Reduce the delay of inter-cell mobility. 3. Provide good communication performance. 4. Provide high reliability. Some embodiments of the present disclosure can be used in many applications. Chipset suppliers, video system development suppliers, automobile (including cars, trains, trucks, buses, bicycles, motorcycles, helmets, etc.) manufacturers, drone (unmanned aerial vehicle) manufacturers, smart phone manufacturers, communication equipment manufacturers for public safety purposes, AR (Augmented Reality, Augmented Reality) / VR (Virtual Reality, Virtual Reality) / MR (Mixed Reality, Mixed Reality) (e.g., games, conferences / seminars, educational purposes) equipment manufacturers use some embodiments of the present disclosure. Some embodiments of the present disclosure are a combination of "techniques / processes" that can be adopted in video standards to create final products. Some embodiments of the present disclosure propose technical mechanisms. At least one proposed solution, method, system and device of some embodiments of the present disclosure can be used for current and / or new / future standards regarding communication systems (such as UE, base station and / or communication system). Compatible products follow at least one proposed solution, method, system and device of some embodiments of the present disclosure. The proposed solutions, methods, systems and devices are widely used in UE, base station and / or communication system. In the case of implementing at least one proposed solution, method, system and device of some embodiments of the present disclosure, at least one modification is considered to be made to the method and device of the physical downlink control channel (PDCCH) command random access channel (RACH) for mobility for standardization.

[0085] Fig.10 is an example of a computing device 1100 according to an embodiment of the present disclosure. Any suitable computing device may be used to perform the operations described herein. For example, Fig.10 It is shown that any suitably configured hardware and / or software may be used to implement Figures 1 to 9 An example of a computing device 1100 of some embodiments of the present invention is provided. In some embodiments, the computing device 1100 may include a processor 1112 that is communicatively coupled to a memory 1114 and executes computer executable program code and / or accesses information stored in the memory 1114. The processor 1112 may include a microprocessor, an application specific integrated circuit ("ASIC"), a state machine, or other processing device. The processor 1112 may include any number (including one) of processing devices. Such a processor may include or may communicate with a computer readable medium storing instructions that, when executed by the processor 1112, cause the processor to perform the operations described herein.

[0086] Memory 1114 may include any suitable non-transient computer-readable medium. Computer-readable media may include any electronic, optical, magnetic or other storage device capable of providing computer-readable instructions or other program codes to the processor. Non-limiting examples of computer-readable media include disks, memory chips, read-only memories (ROMs), random access memories (RAMs), application-specific integrated circuits (ASICs), configured processors, optical storage devices, tapes or other magnetic storage devices, or any other medium from which a computer processor can read instructions. These instructions may include processor-specific instructions generated by a compiler and / or interpreter according to a code written in any suitable computer programming language (including, for example, C, C++, C#, visual basic, java, python, perl, javascript, and actionscript).

[0087] The computing device 1100 may also include a bus 1116. The bus 1116 may communicatively couple one or more components of the computing device 1100. The computing device 1100 may also include a plurality of external or internal devices, such as input devices or output devices. For example, the computing device 1100 is shown with an input / output ("I / O") interface 1118, which may receive input from one or more input devices 1120 or provide output to one or more output devices 1122. One or more input devices 1120 and one or more output devices 1122 may be communicatively coupled to the I / O interface 1118. The communicatively coupling may be achieved via any suitable means (e.g., via a connection of a printed circuit board, via a connection of a cable, via communication via wireless transmission, etc.). Non-limiting examples of the input device 1120 include a touch screen (e.g., one or more cameras for imaging a touch area or a pressure sensor for detecting pressure changes caused by a touch), a mouse, a keyboard, or any other device that may be used to generate input events in response to a physical action of a user of the computing device. Non-limiting examples of output device 1122 include a liquid crystal display (LCD) screen, an external monitor, speakers, or any other device that can be used to display or otherwise present output generated by the computing device.

[0088] The computing device 1100 can execute program code that configures the processor 1112 to perform the above Figures 1 to 9 The program code may reside in the memory 1114 or any suitable computer-readable medium and may be executed by the processor 1112 or any other suitable processor.

[0089] The computing device 1100 may also include at least one network interface device 1124. The network interface device 1124 may include any device or group of devices suitable for establishing a wired data connection or a wireless data connection with one or more data networks 1128. Non-limiting examples of the network interface device 1124 include an Ethernet network adapter, and / or a modem, etc. The computing device 1100 may send messages as electronic signals or optical signals via the network interface device 1124.

[0090] Fig.11 1 is a block diagram of an example of a communication system 1200 according to an embodiment of the present disclosure. The embodiments described herein may be implemented in the communication system 1200 using any suitably configured hardware and / or software. Fig.11 A communication system 1200 is shown, which includes a radio frequency (RF) circuit 1210, a baseband circuit 1220, an application circuit 1230, a memory / storage device 1240, a display 1250, a camera 1260, a sensor 1270 and an input / output (I / O) interface 1280, which are coupled to each other at least as shown.

[0091] Application circuit 1230 may include circuits such as, but not limited to, one or more single-core processors or multi-core processors. The processor may include any combination of general-purpose processors and special-purpose processors, such as a graphics processor, an application processor. The processor may be coupled to a memory / storage device and configured to execute instructions stored in the memory / storage device to enable various applications and / or operating systems to run on the system. Communication system 1200 may execute program code that configures application circuit 1230 to perform the above-mentioned Figures 1 to 9 The program code may reside in the application circuit 1230 or any suitable computer-readable medium and may be executed by the application circuit 1230 or any other suitable processor.

[0092] The baseband circuit 1220 may include circuits, such as but not limited to one or more single-core processors or multi-core processors. The processor may include a baseband processor. The baseband circuit may handle various wireless control functions, and the various wireless control functions may enable communication with one or more wireless networks via RF circuits. The wireless control functions may include but are not limited to signal modulation, encoding, decoding, wireless frequency shifting, etc. In some embodiments, the baseband circuit may provide communications compatible with one or more wireless technologies. For example, in some embodiments, the baseband circuit may support communications with an evolved universal terrestrial radio access network (EUTRAN) and / or other wireless metropolitan area networks (WMAN), wireless local area networks (WLAN), and wireless personal area networks (WPAN). An embodiment in which the baseband circuit is configured to support wireless communications of more than one wireless protocol may be referred to as a multi-mode baseband circuit.

[0093] In various embodiments, the baseband circuit 1220 may include circuits for operating on signals that are not strictly considered to be at baseband frequencies. For example, in some embodiments, the baseband circuit may include circuits for operating on signals having an intermediate frequency (which is between the baseband frequency and the radio frequency). The RF circuit 1210 may use modulated electromagnetic radiation to achieve communication with a wireless network through a non-solid medium. In various embodiments, the RF circuit may include switches, filters, amplifiers, etc. to facilitate communication with a wireless network. In various embodiments, the RF circuit 1210 may include circuits for operating on signals that are not strictly considered to be at radio frequencies. For example, in some embodiments, the RF circuit may include circuits for operating on signals having an intermediate frequency (which is between the baseband frequency and the radio frequency).

[0094] In various embodiments, the above Figures 1 to 9The transmitter circuit, control circuit or receiver circuit discussed in some embodiments of the present invention may be implemented in whole or in part in one or more of the RF circuit, baseband circuit and / or application circuit. As used herein, "circuit" may refer to, be part of or include an application-specific integrated circuit (ASIC) that executes one or more software or firmware programs, an electronic circuit, a processor (shared processor, dedicated processor or processor group) and / or a memory (shared memory, dedicated memory or memory group), a combinational logic circuit and / or other suitable hardware components that provide the described functions. In some embodiments, the electronic device circuit may be implemented in one or more software modules or firmware modules, or the functions associated with the circuit may be implemented by one or more software modules or firmware modules. In some embodiments, some or all of the components of the baseband circuit, application circuit, and / or memory / storage device may be implemented together on a system on a chip (system on a chip, SOC). The memory / storage device 1240 may be used to load and store data and / or instructions, for example, data and / or instructions for the system. The memory / storage of one embodiment may include any combination of suitable volatile memory (such as dynamic random access memory (DRAM)) and / or non-volatile memory (such as flash memory).

[0095] In various embodiments, the I / O interface 1280 may include one or more user interfaces designed to implement the interaction between the user and the system and / or a peripheral component interface designed to implement the interaction between the peripheral component and the system. The user interface may include, but is not limited to, a physical keyboard or key, a touch pad, a speaker, a microphone, etc. The peripheral component interface may include, but is not limited to, a non-volatile memory port, a universal serial bus (universal serial bus, USB) port, an audio jack, and a power interface. In various embodiments, the sensor 1270 may include one or more sensing devices to determine environmental conditions and / or location information related to the system. In some embodiments, the sensor may include, but is not limited to, a gyroscope sensor, an accelerometer, a proximity sensor, an ambient light sensor, and a positioning unit. The positioning unit may also be a part of a baseband circuit and / or an RF circuit, or may interact with a baseband circuit and / or an RF circuit to communicate with a component of a positioning network (e.g., a global positioning system (global positioning system, GPS) satellite).

[0096] In various embodiments, the display 1250 may include a display, such as a liquid crystal display and a touch screen display. In various embodiments, the communication system 1200 may be a mobile computing device, such as but not limited to a laptop computing device, a tablet computing device, a netbook, an ultrabook, a smart phone, AR / VR glasses, etc. In various embodiments, the system may have more or fewer components and / or different architectures. Where appropriate, the methods described herein may be implemented as a computer program. The computer program may be stored on a storage medium (such as a non-transitory storage medium).

[0097] It is understood by those of ordinary skill in the art that each of the units, algorithms and steps described and disclosed in the embodiments of the present disclosure can be implemented using electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are run on hardware or software depends on the design requirements of the application conditions and technical plans. Those of ordinary skill in the art can use different ways to implement each specific function, and such implementation should not exceed the scope of the present disclosure. It is understood by those of ordinary skill in the art that since the working processes of the above-mentioned systems, devices and units are basically the same, he / she can refer to the working processes of the systems, devices and units in the above-mentioned embodiments. For ease of description and simplicity, these workflows will not be described in detail.

[0098] It is understood that the systems, devices and methods disclosed in the embodiments of the present disclosure may also be implemented in other ways. The above embodiments are exemplary only. The division of units is based only on logical functions, and there are other divisions in implementation. Multiple units or components may be combined or integrated into another system. It is also possible to omit or skip some features. On the other hand, the mutual coupling, direct coupling or communication coupling shown or discussed is operated indirectly or communicatively through some ports, devices or units in an electrical, mechanical or other form.

[0099] The units used for explanation as separate components may or may not be physically separated. The units shown may or may not be physical units, i.e., located in one place or distributed over multiple network units. Some or all of the units are used according to the purpose of the embodiment. In addition, each of the functional units in each of the embodiments may be integrated into one processing unit, be physically independent, or be integrated into one processing unit with two or more units.

[0100] If the software functional unit is implemented as a product and is used and sold, the software functional unit can be stored in a readable storage medium in a computer. Based on this understanding, the technical plan proposed in the present disclosure can be implemented in the form of a software product in general or in part. Alternatively, a part of the technical plan that is beneficial to conventional technology is implemented in the form of a software product. The software product in the computer is stored in a storage medium, including multiple instructions to enable a computing device (such as a personal computer, a server, or a network device) to run all or part of the steps disclosed in the embodiments of the present disclosure. The storage medium includes: a USB disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a floppy disk, or other types of media capable of storing program code.

[0101] While the present disclosure has been described in connection with what is considered to be the most practical and preferred embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments but is intended to cover various arrangements made without departing from the scope of the broadest interpretation of the appended claims.

Claims

1. A method for a user equipment UE to use a physical downlink control channel PDCCH to command a random access channel RACH for mobility, comprising: receiving a configuration of a first candidate cell list from a base station; receiving, from the base station, a RACH configuration for each non-serving cell included in the first candidate cell list; as well as A first control signaling is received from the base station, wherein the first control signaling instructs the UE to send a physical random access channel PRACH to a first non-serving cell included in the first candidate cell list.

2. The method according to claim 1, further comprising: A PRACH preamble is sent according to the configuration of the first candidate cell list, the RACH configuration and the first control signaling.

3. The method according to claim 2, wherein: The UE is configured to send the PRACH preamble code to the first non-serving cell, so that the first non-serving cell measures the uplink timing of the UE.

4. The method according to claim 2, further comprising: A RACH response is received from the base station.

5. The method according to any one of claims 1 to 4, wherein: The configuration of the first candidate cell list and / or the RACH configuration is sent in a radio resource control RRC.

6. The method according to any one of claims 1 to 5, wherein: The first control signaling includes a media access control MAC control element CE or downlink control information DCI.

7. The method according to claim 6, wherein: The DCI is DCI format X or DCI format 1_0.

8. The method according to any one of claims 1 to 7, wherein: The first control signaling indicates one or more of the following information: An indicator for indicating the first non-serving cell to which the UE in the first candidate cell list is instructed to send a PRACH preamble code; Indicator of the cell's synchronization signal / physical broadcast channel SS / PBCH; An indicator of a random access preamble index; An indicator of a PRACH mask index; An indicator used to indicate whether the UE expects a random access response RAR message.

9. A method for a base station to use a physical downlink control channel (PDCCH) for mobility to command a random access channel (RACH), comprising: Sending configuration of a first candidate cell list to a user equipment UE; Sending, to the UE, a RACH configuration for each non-serving cell included in the first candidate cell list; as well as A first control signaling is sent to the UE, wherein the first control signaling instructs the UE to send a physical random access channel PRACH to a first non-serving cell included in the first candidate cell list.

10. The method according to claim 1, further comprising: A PRACH preamble is received from the UE according to: a configuration of the first candidate cell list, the RACH configuration, and the first control signaling.

11. The method according to claim 10, wherein: The base station is configured in the first non-serving cell to receive the PRACH preamble to measure uplink timing of the UE.

12. The method according to claim 10, further comprising: A RACH response is sent to the UE.

13. The method according to any one of claims 9 to 12, wherein: The configuration of the first candidate cell list and / or the RACH configuration is sent in a radio resource control RRC.

14. The method according to any one of claims 9 to 13, wherein: The first control signaling includes a media access control MAC control element CE or downlink control information DCI.

15. The method according to claim 14, wherein: The DCI is DCI format X or DCI format 1_0.

16. The method according to any one of claims 9 to 15, wherein: The first control signaling indicates one or more of the following information: An indicator for indicating the first non-serving cell to which the base station in the first candidate cell list instructs the UE to send a PRACH preamble code; Indicator of the cell's synchronization signal / physical broadcast channel SS / PBCH; An indicator of a random access preamble index; An indicator of a PRACH mask index; An indicator used to indicate whether the UE expects a random access response RAR message.

17. A user equipment UE, comprising: The receiver is configured as: receiving a configuration of a first candidate cell list from a base station; receiving, from the base station, a RACH configuration for each non-serving cell included in the first candidate cell list; as well as A first control signaling is received from the base station, wherein the first control signaling instructs the UE to send a physical random access channel PRACH to a first non-serving cell included in the first candidate cell list.

18. A base station, comprising: The transmitter is configured as: Sending configuration of a first candidate cell list to a user equipment UE; Sending, to the UE, a RACH configuration for each non-serving cell included in the first candidate cell list; as well as A first control signaling is sent to the UE, wherein the first control signaling instructs the UE to send a physical random access channel PRACH to a first non-serving cell included in the first candidate cell list.

19. A user equipment UE, comprising: Memory; Transceiver; as well as a processor coupled to the memory and the transceiver; The UE is configured to perform the method according to any one of claims 1 to 8.

20. A base station, comprising: Memory; Transceiver; as well as a processor coupled to the memory and the transceiver; The base station is configured to perform the method according to any one of claims 9 to 16.

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