Method and device for uplink synchronization in wireless communication

Abstract

The invention discloses a method and a device used for uplink synchronization in wireless communication. A first node receives a first signaling on a first cell, the first signaling indicating a second cell; in response to receiving the first signaling, transmitting a first random access sequence on the second cell and starting to evaluate whether a first set of conditions for the second cell is satisfied; monitoring a first timing advance, wherein the first timing advance aims at the first random access sequence; wherein monitoring the first timing advance on the first cell or on the second cell at least depends on whether the first set of conditions is satisfied; when the first condition set is not satisfied, monitoring the first timing advance on the first cell; the first condition set comprises that the channel quality of the first cell is poorer than a first threshold value. According to the invention, the cell switching delay can be effectively reduced.

Description

Technical Field

[0001] The present application relates to a method and apparatus for uplink synchronization in a wireless communication system, and more particularly to a method and apparatus for uplink synchronization when supporting cell switching in wireless communication. Background Art

[0002] In the future, the application scenarios of wireless communication systems will become more and more diversified, and different application scenarios will put forward different performance requirements for the system. In order to meet the different performance requirements of various application scenarios, the 3GPP (3rd Generation Partner Project) RAN (Radio Access Network) #72 plenary meeting decided to study the new radio technology (NR) (or 5G), and the WI (Work Item) of the new radio technology was passed at the 3GPP RAN #75 plenary meeting, and the standardization work on NR began.

[0003] In the new air interface technology, cell switching provides effective mobility support. The basic requirement of cell switching is to reduce the switching delay and reduce the impact on delay-sensitive services. Uplink synchronization is one of the basic requirements of wireless communication. In order to adapt to various application scenarios and meet different needs, 3GPP has been evolving uplink synchronization technology. Summary of the invention

[0004] When a UE (User Equipment) moves from the coverage of one cell to the coverage of another cell, it is necessary to change the UE's serving cell, i.e. switch from the source cell to the target cell. Existing cell switching is usually triggered by L3 (Layer 3) measurement and is implemented by RRC (Radio Resource Control) signaling, including reconfiguration with synchronization. Cell switching implemented at L3 has the characteristics of long delay and long service interruption time. To overcome the above shortcomings, 3GPP (3rd Generation Partner Project) RAN (Radio Access Network) introduced Dual Connectivity (DC), Conditional PSCell (Primary SCG (Secondary Cell Group) Cell) change (CPC), Conditional PSCell Addition (CPA), Conditional Handover (CHO) and other technologies in Rel (version)-17, but these technologies are still based on L3 implementation and cannot completely solve the above problems. At the 3GPP RAN#94e plenary meeting, it was decided to start the WI (Work Item) standardization work on the cell switching technology based on L1 / L2 (Layer 1 / Layer 2). The design goal of the cell switching based on L1 / L2 is to achieve fast switching of UE serving cells.

[0005] Before the UE performs uplink data communication, it must first obtain uplink synchronization (Uplink synchronization), that is, uplink time alignment (Uplink Time Alignment). The network can actively send timing advance (TA) to adjust the uplink timing; or, the UE can adjust the uplink timing by initiating a random access process, that is, by sending a random access sequence and receiving a random access response to obtain timing advance. How to quickly obtain uplink synchronization in cell switching to achieve fast cell switching needs to be studied.

[0006] In response to the above problems, the present application discloses a solution. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other. Although the original intention of the present application is for the Uu air interface, the present application can also be used for the PC5 port. Furthermore, although the original intention of the present application is for the cell switching scenario, the present application is also applicable to other scenarios facing similar problems, including but not limited to multi-antenna systems, multi-TRP (Transmission Reception Point, sending and receiving nodes) systems, capacity enhancement systems, short-range communication systems, unlicensed frequency domain communications, IoT (Internet of Things, Internet of Things), URLLC (UltraReliable Low Latency Communication, ultra-robust low-latency communication) networks, vehicle networking communications, relay communications, dual-connectivity (dual-connectivity, DC), multi-connectivity (multi-connectivity, MC), etc., to achieve similar technical effects. In addition, the use of a unified solution for different scenarios (including but not limited to V2X scenarios and communication scenarios between terminals and base stations) also helps to reduce hardware complexity and costs. In particular, the interpretation of the terminology, nouns, functions, and variables in this application (unless otherwise specified) can refer to the definitions in the 3GPP specification protocols TS38 series and TS37 series.

[0007] The present application discloses a method in a first node used for wireless communication, characterized by comprising:

[0008] receiving a first signaling on a first cell, wherein the first signaling indicates a second cell;

[0009] In response to receiving the first signaling, sending a first random access sequence on the second cell and starting to evaluate whether a first condition set for the second cell is satisfied;

[0010] monitoring a first timing advance, the first timing advance being for the first random access sequence;

[0011] Among them, whether to monitor the first timing advance on the first cell or the second cell depends at least on whether the first condition set is met; when the first condition set is not met, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

[0012] As an embodiment, the first cell is a service cell of the first node.

[0013] As an embodiment, the first cell is a source cell of cell switching.

[0014] As an embodiment, the second cell is a candidate cell for cell switching of the first node.

[0015] As an embodiment, when the first condition set for the second cell is met, the second cell is a target cell for cell switching.

[0016] As an embodiment, the first signaling includes cell switching configuration information.

[0017] As an embodiment, the above method can speed up obtaining the first timing advance by sending the first random access sequence on the second cell after receiving the first signaling, that is, speed up obtaining uplink synchronization of the cell switching candidate cell and reduce the cell switching delay.

[0018] As an embodiment, an evaluation result of whether the first condition set for the second cell is satisfied is used to determine whether to trigger a cell handover to the second cell.

[0019] As an embodiment, the above method can implement cell switching triggered by UE.

[0020] As an embodiment, the cell switching triggered by the UE can speed up the cell switching process and reduce the cell switching delay.

[0021] As an embodiment, the UE-triggered cell switching can omit the signaling of the network-triggered cell switching.

[0022] As an embodiment, the cell switching triggered by the UE is based on the result of UE measurement and evaluation, which can improve the robustness of the switching.

[0023] As an embodiment, the above method determines whether to monitor the first timing advance in the first cell or in the second cell according to whether the first condition set is satisfied, which can improve the robustness of the first timing advance reception.

[0024] As an embodiment, the above method can effectively support the demand for rapid cell switching caused by rapid channel changes and reduce service interruption time.

[0025] As an embodiment, the problem to be solved by the present application is: how to quickly obtain timing advance in cell switching triggered by UE.

[0026] As an embodiment, the solution of the present application is: sending a first random access sequence after receiving the first signaling; in the process of evaluating whether the first condition set for the second cell is met, monitoring the first timing advance on the first cell or on the second cell.

[0027] As an embodiment, the above method is applicable to cell switching triggered by UE.

[0028] As an embodiment, the above method is applicable to CHO (Conditional Handover).

[0029] As an embodiment, the above method is applicable to conditional LTM (L1 / L2-triggered mobility).

[0030] According to one aspect of the present application, it includes:

[0031] In response to sending the first random access sequence, starting a first time window;

[0032] Among them, whether to monitor the first timing advance in the first cell or the second cell depends on whether the first time window expires; when the first condition set is met and the first time window has not expired, the first timing advance is monitored in the second cell; the first timing advance is not received from the first cell before the first condition set is met.

[0033] As an embodiment, the above method avoids re-initiating the random access process before the first time window expires, which can reduce signaling.

[0034] As an embodiment, the above method can reduce the cell switching delay by monitoring the first timing advance before the first time window expires.

[0035] According to one aspect of the present application, it includes:

[0036] In response to receiving the first timing advance on the first cell, starting a second time window;

[0037] The first set of conditions is not met before the first timing advance is received on the first cell.

[0038] As an embodiment, in the above method, the first node determines whether the second cell is uplink time aligned through the second time window.

[0039] As an embodiment, the second time window is a time alignment timer (timeAlignmentTimer, TAT).

[0040] According to one aspect of the present application, it includes:

[0041] In response to the first set of conditions being satisfied when the second time window is running, sending a first wireless signal on the second cell when the second time window is running;

[0042] The first timing advance is applied to the first wireless signal; the first wireless signal carries the first uplink data.

[0043] As an embodiment, the first wireless signal indicates that the cell switching is completed.

[0044] As an embodiment, the above method quickly completes cell switching.

[0045] According to one aspect of the present application, it includes:

[0046] In response to the expiration of the second time window, sending a second random access sequence on the second cell;

[0047] Wherein, when the second time window is running, the first condition set is not satisfied, or, when the second time window is running, the first condition set is satisfied and the first uplink data is not successfully sent.

[0048] According to one aspect of the present application, it includes:

[0049] Monitoring the first timing advance on the second cell includes receiving the first timing advance on time-frequency resources indicated by the first configured downlink allocation;

[0050] The first configured downlink allocation is one of multiple configured downlink allocations.

[0051] As an embodiment, the above method can receive the first timing advance in time.

[0052] As an embodiment, the above method can save signaling.

[0053] According to one aspect of the present application, it includes:

[0054] In response to receiving the first random access sequence, a first downlink allocation is activated, the first downlink allocation indicating the plurality of configured downlink allocations;

[0055] The first signaling configures the first downlink allocation.

[0056] As an embodiment, the above method can save downlink air interface resources.

[0057] The present application discloses a method used in a second node of wireless communication, characterized by comprising:

[0058] Sending a first signaling on a first cell, where the first signaling indicates a second cell;

[0059] Wherein, as a response to the first signaling being received, a first random access sequence is sent on the second cell, and an evaluation is started for whether a first condition set of the second cell is satisfied; a first timing advance is monitored, and the first timing advance is for the first random access sequence; whether the first timing advance is monitored on the first cell or the second cell depends at least on whether the first condition set is satisfied; when the first condition set is not satisfied, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold;

[0060] or,

[0061] receiving a first random access sequence on a second cell;

[0062] In which, a first signaling is received on a first cell, and the first signaling indicates the second cell; as a response to the first signaling being received, the first random access sequence is sent and an evaluation is started on whether a first condition set for the second cell is met; a first timing advance is monitored, and the first timing advance is for the first random access sequence; whether the first timing advance is monitored on the first cell or the second cell depends at least on whether the first condition set is met; when the first condition set is not met, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

[0063] As an embodiment, the above method is applicable to a scenario in which the second node is a base station of the first cell, or the second node is a base station of the second cell.

[0064] According to one aspect of the present application, it includes:

[0065] Sending a first signaling on a first cell, where the first signaling indicates a second cell;

[0066] Wherein, as a response to the first signaling being received, a first random access sequence is sent on the second cell, and an evaluation is started for whether a first condition set of the second cell is satisfied; a first timing advance is monitored, and the first timing advance is for the first random access sequence; whether the first timing advance is monitored on the first cell or the second cell depends at least on whether the first condition set is satisfied; when the first condition set is not satisfied, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold;

[0067] or,

[0068] receiving a first random access sequence on a second cell;

[0069] The first signaling is received on the first cell, and the first signaling indicates the second cell; as a response to the first signaling being received, the first random access sequence is sent and an evaluation is started for whether a first condition set for the second cell is satisfied; a first timing advance is monitored, and the first timing advance is for the first random access sequence; whether the first timing advance is monitored on the first cell or the second cell depends at least on whether the first condition set is satisfied; when the first condition set is not satisfied, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold;

[0070] Both of the above actions are performed.

[0071] As an embodiment, the above method is applicable to a scenario where the second node is both a base station of the first cell and a base station of the second cell.

[0072] According to one aspect of the present application, it includes:

[0073] In response to the first random access sequence being sent, a first time window is started;

[0074] Among them, whether the first timing advance is monitored in the first cell or the second cell depends on whether the first time window expires; when the first condition set is met and the first time window has not expired, the first timing advance is monitored in the second cell; before the first condition set is met, the first timing advance is not received from the first cell.

[0075] According to one aspect of the present application, it includes:

[0076] In response to the first timing advance being received on the first cell, a second time window is started;

[0077] The first set of conditions is not satisfied before the first timing advance is received on the first cell.

[0078] According to one aspect of the present application, it includes:

[0079] receiving a first wireless signal on the second cell;

[0080] The second time window is in a running state and the first condition set is satisfied; the first timing advance is applied to the first wireless signal; and the first wireless signal carries the first uplink data.

[0081] According to one aspect of the present application, it includes:

[0082] A second random access sequence is received on the second cell; wherein the second time window has expired; the first condition set is not satisfied when the second time window is running, or the first condition set is satisfied and the first uplink data is not successfully received when the second time window is running.

[0083] According to one aspect of the present application, it includes:

[0084] The first timing advance is sent on a time-frequency resource indicated by a first configured downlink allocation; wherein the first configured downlink allocation is one of a plurality of configured downlink allocations.

[0085] According to one aspect of the present application, it includes:

[0086] activating, in response to receiving the first random access sequence, a first downlink allocation indicating the plurality of configured downlink allocations;

[0087] The first signaling configures the first downlink allocation.

[0088] As an embodiment, the above method can save downlink air interface resources.

[0089] As an embodiment, the above method can accelerate the sending of the first wireless signal.

[0090] The present application discloses a first node used for wireless communication, characterized in that it includes:

[0091] A first receiver receives a first signaling on a first cell, wherein the first signaling indicates a second cell;

[0092] A first processor, in response to receiving the first signaling, sends a first random access sequence on the second cell and starts evaluating whether a first condition set for the second cell is satisfied; monitors a first timing advance, the first timing advance being for the first random access sequence;

[0093] Among them, whether to monitor the first timing advance on the first cell or the second cell depends at least on whether the first condition set is met; when the first condition set is not met, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

[0094] The present application discloses a second node used for wireless communication, characterized in that it includes:

[0095] A first transmitter sends a first signaling on a first cell, wherein the first signaling indicates a second cell;

[0096] Wherein, as a response to the first signaling being received, a first random access sequence is sent on the second cell, and an evaluation is started for whether a first condition set of the second cell is satisfied; a first timing advance is monitored, and the first timing advance is for the first random access sequence; whether the first timing advance is monitored on the first cell or the second cell depends at least on whether the first condition set is satisfied; when the first condition set is not satisfied, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold;

[0097] or,

[0098] A second processor receives a first random access sequence on a second cell;

[0099] In which, a first signaling is received on a first cell, and the first signaling indicates the second cell; as a response to the first signaling being received, the first random access sequence is sent and an evaluation is started on whether a first condition set for the second cell is met; a first timing advance is monitored, and the first timing advance is for the first random access sequence; whether the first timing advance is monitored on the first cell or the second cell depends at least on whether the first condition set is met; when the first condition set is not met, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

[0100] As an embodiment, the second node is a base station of the first cell.

[0101] As an embodiment, the second node is a base station of the second cell.

[0102] According to one aspect of the present application, it includes:

[0103] The second node includes the first transmitter and the second processor.

[0104] As an embodiment, the second node is both a base station of the first cell and a base station of the second cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0105] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0106] Figure 1A signal processing flow chart in a first node according to an embodiment of the present application is illustrated;

[0107] Figure 2 A schematic diagram illustrating a network architecture according to an embodiment of the present application is illustrated;

[0108] Figure 3 A schematic diagram illustrating a wireless protocol architecture of a user plane and a control plane according to an embodiment of the present application;

[0109] Figure 4 A hardware module schematic diagram of a communication device according to an embodiment of the present application is illustrated;

[0110] Figure 5 An example of a wireless signal transmission flow chart according to an embodiment of the present application is provided;

[0111] Figure 6 An example of a wireless signal transmission flow chart according to an embodiment of the present application is provided;

[0112] Figure 7 An example of a wireless signal transmission flow chart according to an embodiment of the present application is provided;

[0113] Figure 8 A schematic diagram illustrating monitoring a first timing advance on a second cell according to an embodiment of the present application is illustrated;

[0114] Fig. 9 An example structural block diagram of a processing device in a first node according to an embodiment of the present application is shown;

[0115] Fig.10 The structural block diagram of the processing device in the second node according to an embodiment of the present application is illustrated. DETAILED DESCRIPTION

[0116] The technical solution of the present application will be further described in detail below in conjunction with the accompanying drawings. It should be noted that, in the absence of conflict, the embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other.

[0117] Example 1

[0118] Embodiment 1 illustrates a signal processing flow chart in a first node according to an embodiment of the present application, as shown in the attached Figure 1 shown.

[0119] In embodiment 1, the first node 100 receives a first signaling on a first cell in step 101, wherein the first signaling indicates a second cell; in step 102, as a response to receiving the first signaling, sends a first random access sequence on the second cell and starts to evaluate whether a first condition set for the second cell is met; in step 103, monitors a first timing advance, wherein the first timing advance is for the first random access sequence; wherein whether the first timing advance is monitored on the first cell or on the second cell depends at least on whether the first condition set is met; when the first condition set is not met, monitors the first timing advance on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

[0120] As an embodiment, first signaling is received on a first cell, where the first signaling indicates a second cell.

[0121] As an embodiment, the first cell is a SpCell (Special Cell) of the first node.

[0122] As an embodiment, the first cell is a PCell (Primary Cell) of the first node.

[0123] As an embodiment, the first signaling indicates at least one candidate cell, and the second cell is any candidate cell among the at least one candidate cell.

[0124] As an embodiment, the at least one candidate cell is configured according to a measurement report reported by the first node.

[0125] As an embodiment, the measurement report is an L3 (layer 3) measurement report.

[0126] As an embodiment, the measurement report is an L1 (layer 1) measurement report.

[0127] As an embodiment, the at least one candidate cell is for cell switching.

[0128] As an embodiment, the at least one candidate cell is for conditional switching, and the conditional switching is a cell switching triggered by the UE.

[0129] As an embodiment, the cell switching includes layer 3 cell switching.

[0130] As an embodiment, the layer 3 cell switching includes CHO (Conditional Handover).

[0131] As an embodiment, the cell switching includes cell switching of protocol layers below layer 3.

[0132] As an embodiment, the cell switching of the protocol layers below Layer 3 includes conditional LTM.

[0133] As an embodiment, the second cell is not a service cell of the first node.

[0134] As an embodiment, the second cell is an SCell (secondary cell) of the first node.

[0135] As an embodiment, the second cell waits to become a service cell of the first node.

[0136] As an embodiment, the first signaling includes an identifier of the second cell.

[0137] As an embodiment, the identifier of the second cell is PhysCellId (physical cell identifier).

[0138] As an embodiment, the identifier of the second cell is candidateCellID (candidate cell identifier).

[0139] As an embodiment, the first signaling configures a candidate cell configuration for each candidate cell in the at least one candidate cell, and the candidate cell configuration is indicated by a candidate identifier (candidate ID).

[0140] As an embodiment, the candidate cell configuration is applied to conditional switching.

[0141] As an embodiment, the candidate cell configuration is applied to CHO.

[0142] As an embodiment, the candidate cell configuration is applied to conditional LTM.

[0143] As an embodiment, the candidate cell configuration is applied to CPC (Conditional PSCell Change, conditional primary SCG (Secondary Cell Group) cell change).

[0144] As an embodiment, the candidate cell configuration is applied to CPA (Conditional PSCellAddition, conditional SCG cell addition).

[0145] As an embodiment, the first signaling is higher layer signaling.

[0146] As an embodiment, the higher layer signaling is RRC (Radio Resource Control) signaling.

[0147] As an embodiment, the higher layer signaling is RRCReconfiguration.

[0148] As an embodiment, the higher layer signaling is LTMConfig (LTM configuration).

[0149] As an embodiment, the higher layer signaling is MAC (Medium Access Control) CE (Control Element).

[0150] As an embodiment, the higher layer signaling includes condLTMConfig (conditional LTM configuration).

[0151] As an embodiment, the higher layer signaling includes condRRCReconfig (conditional RRC reconfiguration).

[0152] As an embodiment, the higher layer signaling includes ltm-ReferenceConfiguration (LTM reference configuration).

[0153] As an embodiment, the higher layer signaling includes LTM-Candidate.

[0154] As an embodiment, the higher layer signaling includes ltm-CandidateConfig (LTM candidate configuration).

[0155] As an embodiment, the name of the higher layer signaling includes cond (condition).

[0156] As an embodiment, the first signaling is NAS (Non-access stratum) signaling.

[0157] As an embodiment, the first signaling is physical layer signaling.

[0158] As an embodiment, in response to receiving the first signaling, it is started to evaluate whether a first set of conditions for the second cell is met.

[0159] As an embodiment, after receiving the first signaling, it starts to evaluate whether the first condition set for the second cell is met.

[0160] As an embodiment, the first set of conditions for the second cell is network configured.

[0161] As an embodiment, the first condition set includes at least one condition.

[0162] As an embodiment, the first condition set being satisfied means that all conditions in the first condition set are satisfied.

[0163] As an embodiment, the first condition set not being satisfied means that any condition in the first condition set is not satisfied.

[0164] As an embodiment, the evaluating whether the first condition set for the second cell is satisfied includes: performing channel measurement for the second cell and evaluating whether the first condition set is satisfied.

[0165] As an embodiment, the first signaling indicates that the candidate cell configuration for the second cell includes a measurement configuration for the second cell.

[0166] As an embodiment, the measurement configuration for the second cell includes a measurement identifier (measurementID).

[0167] As an embodiment, the first node performs measurement according to a measurement object indicated by the measurement identifier to determine whether the first condition set is satisfied.

[0168] As an embodiment, the first condition set includes conditions for performing cell switching, and the cell switching is triggered by the first node.

[0169] As an embodiment, the first condition set includes an event of executing a cell switch, and the cell switch is triggered by the first node.

[0170] As a sub-embodiment of the above two embodiments, the cell switching is performed at a protocol layer below layer 3.

[0171] As a sub-embodiment of the above two embodiments, the cell switching is performed at the MAC sublayer.

[0172] As a sub-embodiment of the above two embodiments, the cell switching is performed at the physical layer.

[0173] As an embodiment, in response to receiving the first signaling, a first random access sequence is sent on the second cell.

[0174] As an embodiment, the first signaling indicates the air interface resources for sending the first random access sequence on the second cell.

[0175] As an embodiment, the air interface resources include UL (Uplink) / SUL (Supplementary UpLink) indication.

[0176] As an embodiment, the air interface resources include SS (Synchronization Signals) / PBCH (Physical Broadcast Channel) indexes.

[0177] As an embodiment, the air interface resources include a PRACH (Physical Random Access CHannel) mask index.

[0178] As an embodiment, the air interface resources include an index of the first random access sequence.

[0179] As an embodiment, the index of the first random access sequence uniquely identifies the first random access sequence.

[0180] As an embodiment, the random access sequence in the present application means a random access preamble.

[0181] As an embodiment, the first random access sequence is a signature sequence.

[0182] As an embodiment, the first random access sequence is a Gold sequence.

[0183] As an embodiment, the first random access sequence is an M sequence.

[0184] As an embodiment, the first random access sequence is a ZC (Zadoff–Chu) sequence.

[0185] As an embodiment, the first random access sequence is dedicated to the first node.

[0186] As an embodiment, the first random access sequence is configured by the base station of the second cell, and then forwarded to the base station of the first cell and sent to the first node through the first cell.

[0187] As an embodiment, the first random access sequence is sent in a random access opportunity, and the timing of sending the first random access sequence may be earlier than, equal to, or later than the time for starting to evaluate whether the first condition set for the second cell is met.

[0188] As an embodiment, after sending the first random access sequence, the first timing advance is monitored.

[0189] As an embodiment, the first timing advance is for the first random access sequence.

[0190] As an embodiment, the first timing advance for the first random access sequence includes: the first random access sequence is used to determine the first timing advance.

[0191] As an embodiment, the first timing advance for the first random access sequence includes: reception of the first random access sequence is used to trigger sending of the first timing advance.

[0192] As an embodiment, the first timing advance for the first random access sequence includes: sending the first timing advance is a response to receiving the first random access sequence.

[0193] As an embodiment, the first timing advance for the first random access sequence includes: sending of the first timing advance must be caused by sending of the first random access sequence.

[0194] As an embodiment, the first timing advance is used to determine the uplink timing of the second cell.

[0195] As an embodiment, the first timing advance is applied to a TAG (timing advance group) to which the second cell belongs.

[0196] As an embodiment, after receiving the first random access sequence from the second cell, the base station of the second cell can obtain the first timing advance of the sender of the first random access sequence, and the first timing advance is used by the sender of the first random access sequence for uplink timing when performing uplink transmission on the second cell.

[0197] As an embodiment, whether to monitor the first timing advance on the first cell or the second cell depends at least on whether the first condition set is satisfied.

[0198] As an embodiment, whether to monitor the first timing advance on the first cell or the second cell is determined at least according to whether the first condition set is satisfied.

[0199] As an embodiment, monitoring the first timing advance on a cell includes monitoring a PDCCH (Physical Downlink Control CHannel) for the first timing advance on the cell, and the first timing advance is carried in a PDSCH (Physical Downlink Shared CHannel) scheduled by the PDCCH.

[0200] As an embodiment, the monitoring means including searching.

[0201] As an embodiment, the monitoring means including blind decoding of PDCCH, and judging whether the decoding is correct according to CRC (Cyclic Redundancy Check).

[0202] As an embodiment, monitoring the first timing advance on a cell includes receiving a PDSCH on a time-frequency resource preconfigured in the cell, the PDSCH carrying the first timing advance.

[0203] As a sub-embodiment of the above embodiment, the monitoring means including decoding the PDSCH and judging whether the decoding is correct according to a CRC (Cyclic Redundancy Check).

[0204] The sending or receiving of PDSCH in the present application includes: sending or receiving a wireless signal through PDSCH; it is also applicable to other physical channels, including but not limited to PDCCH, PUSCH (Physical Uplink Shared Channel), PUCCH (Physical Uplink Control Channel), and PRACH.

[0205] Decoding PDSCH in the present application includes: decoding a wireless signal received through PDSCH; it is also applicable to other physical channels, including but not limited to PDCCH, PUCCH, and PUSCH.

[0206] As an embodiment, the first node does not monitor the first timing advance on the first cell and the second cell at the same time.

[0207] As an embodiment, whether the first node monitors the first timing advance on the first cell and the second cell at the same time is determined by the UE itself.

[0208] As an embodiment, whether the first node monitors the first timing advance on the first cell and the second cell simultaneously depends on UE capabilities.

[0209] As an embodiment, when the first condition set is not met, the first timing advance is monitored on the first cell.

[0210] As an embodiment, when the first condition set is not satisfied, the first timing advance is monitored on the first cell; whether to monitor the first timing advance on the second cell depends on the receiving capability of the first node.

[0211] The method in the above embodiment can flexibly monitor the first timing advance according to the UE receiving capability; when the UE is capable of monitoring the first timing advance on the second cell at the same time, the reliability of receiving the first timing advance can be improved.

[0212] As an embodiment, when the first condition set is not met, the first timing advance is not monitored on the second cell.

[0213] As an embodiment, the first node does not monitor RAR (random access response) on the second cell after sending the first random access sequence on the second cell; wherein the first condition set is not met.

[0214] The methods in the above two embodiments can reduce the communication interruption time between the first node and the serving cell, and the serving cell includes the first cell.

[0215] As an embodiment, when the first timing advance is sent through the first cell, the first timing advance is carried in the MAC CE.

[0216] As an embodiment, the MAC CE is an Absolute Timing Advance Command.

[0217] As an embodiment, the MAC CE is a Timing Advance Command.

[0218] As an embodiment, the MAC CE is a LTM Cell Switch Command (cell switching command).

[0219] As an embodiment, when monitoring the first timing advance on the first cell, the CRC of the PDCCH for the first timing advance is scrambled by a C-RNTI (Cell-Radio Network Temporary Identifier), and the C-RNTI is configured by the base station of the first cell.

[0220] As an embodiment, the first set of conditions is configured by the network.

[0221] As an embodiment, the first condition set includes that the channel quality of the first cell is worse than a first threshold.

[0222] As an embodiment, the first threshold is a measurement value.

[0223] As an embodiment, the first threshold is a configuration value.

[0224] As an embodiment, the first threshold is a value obtained by linearly processing the measured value and the configured value.

[0225] As an embodiment, the first condition set includes one condition, and the one condition is that the channel quality of the first cell is worse than the first threshold; wherein the first threshold is the channel quality of the second cell.

[0226] As an embodiment, the first condition set includes two conditions, the first of the two conditions being that the channel quality of the first cell is worse than the first threshold; the second of the two conditions being that the channel quality of the second cell is better than a second threshold; wherein the first threshold is configured by the network, and the second threshold is configured by the network.

[0227] As an embodiment, when the channel quality of one cell is less than a threshold, the channel quality of the one cell is worse than the threshold.

[0228] As an embodiment, when the channel quality of one cell is greater than a threshold, the channel quality of the one cell is better than the threshold.

[0229] As an embodiment, the channel quality of a cell is represented by RSRP (Reference Signal Received Power), or RSRQ (Reference Signal Received Quality), or RSSI (Received Signal Strength Indicator), or SINR (Signal to Interference & Noise Ratio).

[0230] As an embodiment, the channel quality of a cell is obtained by measuring a reference signal of the cell.

[0231] As an embodiment, the cell measurement is performed at L3 (layer 3).

[0232] As an embodiment, the cell measurement is performed at a protocol layer below L3 (Layer 3).

[0233] As an embodiment, the cell measurement is performed at L1 (layer 1).

[0234] As an embodiment, the reference signal is SSB (Synchronization Signal Block).

[0235] As an embodiment, the reference signal is SSB (Synchronization Signals / Physical Broadcast Channel).

[0236] As an embodiment, the reference signal is CSI-RS (Channel Status Information-Reference Signal).

[0237] As an embodiment, the channel quality of a cell is obtained by linearly processing a measured value of a reference signal of the cell and a configured offset value.

[0238] As a sub-embodiment of the above embodiment, the configured offset value includes at least one of four offset values: a measurement object specific offset value, a cell specific offset value, an event offset value, and a hysteresis parameter value for an event.

[0239] As an example, the channel quality of the first cell being worse than the first threshold includes: Mp < Mn; where Mp is the channel quality of the first cell; the first threshold is Mn, and Mn is the channel quality of the second cell.

[0240] As an example, the channel quality of the first cell being worse than the first threshold includes: Mp < Thresh1; where Mp is the channel quality of the first cell; the first threshold is Thresh1, and Thresh1 is configured.

[0241] As an example, the channel quality of the second cell being better than the second threshold includes: Mn > Thresh2; where Mn is the channel quality of the second cell; the second threshold is Thresh2, and Thresh2 is configured.

[0242] As an example, the channel quality of the first cell being worse than the first threshold includes: Mn + Ofn + Ocn – Hys > Mp + Ofp + Ocp + Off; where the channel quality of the first cell is Mp + Ofp + Ocp + Off; the first threshold is Mn + Ofn + Ocn – Hys; Mp is the result measured for the first cell; Ofp is the offset value specific to the measurement object for the first cell; Ocp is the cell-specific offset value for the first cell; Off is the offset value for the event; Mn is the result measured for the second cell; Ofn is the offset value specific to the measurement object for the second cell; Ocn is the cell-specific offset value for the second cell; Hys is the hysteresis parameter value for the event; when Mp and Mn are RSRP (Reference Signal Received Power), the units of Mp and Mn are dBm (decibel milliwatt); when Mp and Mn are RSRQ (Reference Signal Received Quality) or RS-SINR (Reference Signal-Signal to Interference & Noise Ratio), the units of Mp and Mn are dB (decibel); the units of Ofn, Ocn, Ofp, Ocp, Hys, and Off are dB.

[0243] As an example, the channel quality of the first cell being worse than the first threshold includes: Mp + Hys < Thresh1; where the channel quality of the first cell is Mp + Hys, the first threshold is Thresh1; Mp is the result measured for the first cell; Hys is the hysteresis parameter value for the event; Thresh1 is configured.

[0244] As an example, the channel quality of the second cell being better than the second threshold includes: the channel quality of the second cell is Mn + Ofn + Ocn – Hys, the second threshold is Thresh2; where Mn is the result measured for the second cell; Ofn is the offset value dedicated to the measurement object for the second cell; Ocn is the cell-specific offset value for the second cell; Hys is the hysteresis parameter value for the event; Thresh2 is configured.

[0245] As an example, when Mp and Mn are RSRP, the units of Mp and Mn are dBm (decibel milliwatt); when Mp and Mn are RSRQ or RS (Reference Signal)-SINR, the units of Mp and Mn are dB (decibel); the units of Ofn, Ocn, and Hys are dB, the unit of Threshold1 is the same as the unit of Mp; the unit of Threshold2 is the same as the unit of Mn.

[0246] Example 2

[0247] Embodiment 2 exemplifies a schematic diagram of a network architecture according to an embodiment of the present application, as shown in the appendix Figure 2 as follows. Figure 2A diagram illustrating a network architecture 200 for NR 5G, LTE (Long-Term Evolution) and LTE-A (Long-Term Evolution Advanced) systems. The NR 5G, LTE or LTE-A network architecture 200 may be referred to as 5GS (5G System) / EPS (Evolved Packet System) 200 or some other suitable terminology. The 5GS / EPS 200 may include one or more UEs (User Equipment) 201, NG-RAN (Next Generation Radio Access Network) 202, 5GC (5G Core Network) / EPC (Evolved Packet Core) 210, HSS (Home Subscriber Server) / UDM (Unified Data Management) 220 and Internet Services 230. The 5GS / EPS may be interconnected with other access networks, but these entities / interfaces are not shown for simplicity. As shown, 5GS / EPS provides packet switching services, however, those skilled in the art will readily appreciate that the various concepts presented throughout this application can be extended to networks providing circuit switching services or other cellular networks. NG-RAN includes NR Node B (gNB) 203 and other gNBs 204. gNB 203 provides user and control plane protocol terminations toward UE 201. gNB 203 can be connected to other gNBs 204 via an Xn interface (e.g., backhaul). gNB 203 may also be referred to as a base station, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a TRP (Transmission Reception Point), or some other suitable term. In a NTN (Non Terrestrial Network, non-terrestrial / satellite network) network, gNB 203 may be a satellite, an aircraft, or a ground base station relayed by a satellite. gNB 203 provides an access point to 5GC / EPC 210 for UE 201.Examples of UE 201 include cellular phones, smart phones, Session Initiation Protocol (SIP) phones, laptop computers, personal digital assistants (PDAs), satellite radios, global positioning systems, multimedia devices, video devices, digital audio players (e.g., MP3 players), cameras, game consoles, drones, aircraft, narrowband Internet of Things devices, machine type communication devices, land vehicles, cars, vehicle-mounted devices, vehicle-mounted communication units, wearable devices, or any other similar functional devices. Those skilled in the art may also refer to UE 201 as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable term. gNB203 is connected to 5GC / EPC210 via the S1 / NG interface. 5GC / EPC210 includes MME (Mobility Management Entity) / AMF (Authentication Management Field) / SMF (Session Management Function) 211, other MME / AMF / SMF214, S-GW (Service Gateway) / UPF (User Plane Function) 212, and P-GW (Packet Data Network Gateway) / UPF213. MME / AMF / SMF211 is the control node that handles signaling between UE201 and 5GC / EPC210. ​​In general, MME / AMF / SMF211 provides bearer and connection management. All user IP (Internet Protocol) packets are transmitted through S-GW / UPF212, which itself is connected to P-GW / UPF213. P-GW provides UE IP address allocation and other functions. P-GW / UPF213 is connected to Internet service 230. Internet service 230 includes operator-corresponding Internet protocol services, which may specifically include Internet, Intranet, IMS (IP Multimedia Subsystem) and PS (Packet Switching) streaming services.

[0248] As an embodiment, the UE201 corresponds to the first node in this application.

[0249] As an embodiment, the NR node B203 corresponds to the second node in this application.

[0250] As an embodiment, the gNB203 is a macro cell base station.

[0251] As an embodiment, the gNB203 is a micro cell base station.

[0252] As an embodiment, the gNB203 is a pico cell base station.

[0253] As an embodiment, the gNB203 is a home base station (Femtocell).

[0254] As an embodiment, the gNB203 is a base station device that supports large delay difference.

[0255] As an embodiment, the gNB203 is a flying platform device.

[0256] As an embodiment, the gNB203 is a satellite device.

[0257] As an embodiment, the gNB203 is a testing device (e.g., a transceiver that simulates some functions of a base station, a signaling tester).

[0258] As an embodiment, the wireless link from the UE201 to the gNB203 is an uplink, and the uplink is used to perform uplink transmission.

[0259] As an embodiment, the wireless link from the gNB203 to the UE201 is a downlink, and the downlink is used to perform downlink transmission.

[0260] As an embodiment, the UE201 and the gNB203 are connected via a Uu interface.

[0261] Example 3

[0262] Embodiment 3 illustrates a schematic diagram of a wireless protocol architecture of a user plane and a control plane according to an embodiment of the present application, as shown in the attached figure. Figure 3 shown. Figure 3 is a schematic diagram illustrating an embodiment of a radio protocol architecture for a user plane 350 and a control plane 300, Figure 3The radio protocol architecture of the control plane 300 of the UE and gNB is shown in three layers: Layer 1, Layer 2, and Layer 3. Layer 1 (L1 layer) is the lowest layer and implements various PHY (physical layer) signal processing functions. The L1 layer will be referred to as PHY 301 in this article. Layer 2 (L2 layer) 305 is above PHY 301 and is responsible for the link between the UE and the gNB through PHY 301. The L2 layer 305 includes the MAC (Medium Access Control) sublayer 302, the RLC (Radio Link Control) sublayer 303, and the PDCP (Packet Data Convergence Protocol) sublayer 304, which terminate at the gNB on the network side. The PDCP sublayer 304 provides data encryption and integrity protection. The PDCP sublayer 304 also provides support for inter-zone mobility of UEs between gNBs. The RLC sublayer 303 provides segmentation and reassembly of data packets, and retransmission of lost data packets through ARQ. The RLC sublayer 303 also provides duplicate data packet detection and protocol error detection. The MAC sublayer 302 provides mapping between logical and transport channels and multiplexing of logical channel identities. The MAC sublayer 302 is also responsible for allocating various radio resources (e.g., resource blocks) in a cell between UEs. The MAC sublayer 302 is also responsible for HARQ (Hybrid Automatic Repeat Request) operations. The RRC (Radio Resource Control) sublayer 306 in Layer 3 (L3 layer) in the control plane 300 is responsible for obtaining radio resources (i.e., radio bearers) and configuring the lower layers using RRC signaling between the gNB and the UE. Although not shown in the figure, a V2X layer may also be provided above the RRC sublayer 306 in the control plane 300 of the UE. The V2X layer is responsible for generating a PC5 QoS parameter group and QoS rules based on the received service data or service request, generating a PC5 QoS flow corresponding to the PC5 QoS parameter group, and sending the PC5 QoS flow identifier and the corresponding PC5QoS parameter group to the AS (Access Stratum) layer for the AS layer to perform QoS processing on the data packets belonging to the PC5 QoS flow identifier; the V2X layer also includes a PC5-S signaling protocol (PC5-Signaling Protocol) sublayer, and the V2X layer is responsible for indicating to the AS layer whether each transmission is a PC5-S transmission or a V2X service data transmission.The wireless protocol architecture of the user plane 350 includes layer 1 (L1 layer) and layer 2 (L2 layer). The wireless protocol architecture in the user plane 350 is substantially the same as the corresponding layers and sublayers in the control plane 300 for the physical layer 351, the PDCP sublayer 354 in the L2 layer 355, the RLC sublayer 353 in the L2 layer 355, and the MAC sublayer 352 in the L2 layer 355, but the PDCP sublayer 354 also provides header compression for upper layer data packets to reduce wireless transmission overhead. The L2 layer 355 in the user plane 350 also includes a SDAP (Service Data Adaptation Protocol) sublayer 356, which is responsible for mapping between QoS (Quality of Service) flows and data radio bearers (DRBs) to support the diversity of services. The wireless protocol architecture of the UE in the user plane 350 may include, at the L2 layer, a SDAP sublayer 356, a PDCP sublayer 354, a portion of or all of the protocol sublayers of the RLC sublayer 353 and the MAC sublayer 352. Although not shown, the UE may also have several upper layers above the L2 layer 355, including a network layer (e.g., an IP layer) terminated at the P-GW on the network side and an application layer terminated at the other end of the connection (e.g., a remote UE, a server, etc.).

[0263] As an example, Figure 3 The wireless protocol architecture in is applicable to the first node in this application.

[0264] As an example, Figure 3 The wireless protocol architecture in is applicable to the second node in this application.

[0265] As an embodiment, the first signaling in the present application is generated in the RRC306.

[0266] As an embodiment, the first random access sequence in the present application is generated in the PHY301 or the PHY351.

[0267] As an embodiment, the second random access sequence in the present application is generated in the PHY301 or the PHY351.

[0268] As an embodiment, the first timing advance in the present application is generated in the MAC302 or the MAC352.

[0269] As an embodiment, the first wireless signal in the present application is generated by the PHY301 or the PHY351.

[0270] As an embodiment, the first uplink data in the present application is generated in the RRC306.

[0271] As an embodiment, the first uplink data in the present application is generated in the PDCP304 or the PDCP354.

[0272] As an embodiment, the first uplink data in the present application is generated by the SDAP356.

[0273] As an embodiment, the first time window in the present application is maintained in the MAC302.

[0274] As an embodiment, the second time window in the present application is maintained in the MAC302.

[0275] As an embodiment, the RRC sublayer 306 in the L3 layer belongs to a higher layer.

[0276] Example 4

[0277] Embodiment 4 illustrates a hardware module schematic diagram of a communication device according to an embodiment of the present application, as shown in the attached Figure 4 shown. Figure 4 is a block diagram of a first communication device 450 and a second communication device 410 communicating with each other in an access network.

[0278] The first communication device 450 includes a controller / processor 459, a memory 460, a data source 467, a transmit processor 468, a receive processor 456, a multi-antenna transmit processor 457, a multi-antenna receive processor 458, a transmitter / receiver 454 and an antenna 452.

[0279] The second communication device 410 includes a controller / processor 475, a memory 476, a data source 477, a receive processor 470, a transmit processor 416, a multi-antenna receive processor 472, a multi-antenna transmit processor 471, a transmitter / receiver 418 and an antenna 420.

[0280] In the transmission from the second communication device 410 to the first communication device 450, at the second communication device 410, the upper layer data packets from the core network or the upper layer data packets from the data source 477 are provided to the controller / processor 475. The core network and the data source 477 represent all the protocol layers above the L2 layer. The controller / processor 475 implements the functionality of the L2 layer. In the transmission from the second communication device 410 to the first communication device 450, the controller / processor 475 provides header compression, encryption, packet segmentation and reordering, multiplexing between logical and transport channels, and radio resource allocation to the first communication device 450 based on various priority metrics. The controller / processor 475 is also responsible for the retransmission of lost packets and signaling to the first communication device 450. The transmit processor 416 and the multi-antenna transmit processor 471 implement various signal processing functions for the L1 layer (i.e., the physical layer). The transmit processor 416 implements coding and interleaving to facilitate forward error correction (FEC) at the second communication device 410, as well as mapping of signal constellations based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The multi-antenna transmit processor 471 performs digital spatial precoding, including codebook-based precoding and non-codebook-based precoding, and beamforming processing on the coded and modulated symbols to generate one or more spatial streams. The transmit processor 416 then maps each spatial stream to a subcarrier, multiplexes it with a reference signal (e.g., a pilot) in the time domain and / or frequency domain, and then uses an inverse fast Fourier transform (IFFT) to generate a physical channel carrying a time-domain multi-carrier symbol stream. The multi-antenna transmit processor 471 then performs a transmit analog precoding / beamforming operation on the time-domain multi-carrier symbol stream. Each transmitter 418 converts the baseband multi-carrier symbol stream provided by the multi-antenna transmit processor 471 into a radio frequency stream, and then provides it to a different antenna 420.

[0281] In the transmission from the second communication device 410 to the first communication device 450, at the first communication device 450, each receiver 454 receives a signal through its corresponding antenna 452. Each receiver 454 recovers the information modulated onto the RF carrier and converts the RF stream into a baseband multi-carrier symbol stream and provides it to the receiving processor 456. The receiving processor 456 and the multi-antenna receiving processor 458 implement various signal processing functions of the L1 layer. The multi-antenna receiving processor 458 performs a receiving analog precoding / beamforming operation on the baseband multi-carrier symbol stream from the receiver 454. The receiving processor 456 uses a fast Fourier transform (FFT) to convert the baseband multi-carrier symbol stream after the receiving analog precoding / beamforming operation from the time domain to the frequency domain. In the frequency domain, the physical layer data signal and the reference signal are demultiplexed by the receiving processor 456, wherein the reference signal will be used for channel estimation, and the data signal is recovered after multi-antenna detection in the multi-antenna receiving processor 458 to any spatial stream destined for the first communication device 450. The symbols on each spatial stream are demodulated and recovered in the receiving processor 456, and soft decisions are generated. The receiving processor 456 then decodes and deinterleaves the soft decisions to recover the upper layer data and control signals transmitted by the second communication device 410 on the physical channel. The upper layer data and control signals are then provided to the controller / processor 459. The controller / processor 459 implements the functions of the L2 layer. The controller / processor 459 may be associated with a memory 460 that stores program codes and data. The memory 460 may be referred to as a computer-readable medium. In the transmission from the second communication device 410 to the first communication device 450, the controller / processor 459 provides multiplexing between transport and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover the upper layer data packets from the second communication device 410. The upper layer data packets are then provided to all protocol layers above the L2 layer. Various control signals may also be provided to the L3 for L3 processing.

[0282] In the transmission from the first communication device 450 to the second communication device 410, at the first communication device 450, the upper layer data packets are provided to the controller / processor 459 using the data source 467. The data source 467 represents all the protocol layers above the L2 layer. Similar to the transmission function at the second communication device 410 described in the transmission from the second communication device 410 to the first communication device 450, the controller / processor 459 implements header compression, encryption, packet segmentation and reordering, and multiplexing between logical and transport channels, and implements L2 layer functions for user plane and control plane. The controller / processor 459 is also responsible for the retransmission of lost packets and signaling to the second communication device 410. The transmit processor 468 performs modulation mapping and channel coding processing, and the multi-antenna transmit processor 457 performs digital multi-antenna spatial precoding, including codebook-based precoding and non-codebook-based precoding, and beamforming processing. Then, the transmit processor 468 modulates the generated spatial stream into a multi-carrier / single-carrier symbol stream, which is then provided to different antennas 452 via the transmitter 454 after analog precoding / beamforming operations in the multi-antenna transmit processor 457. Each transmitter 454 first converts the baseband symbol stream provided by the multi-antenna transmit processor 457 into a radio frequency symbol stream, and then provides it to the antenna 452.

[0283] In the transmission from the first communication device 450 to the second communication device 410, the functions at the second communication device 410 are similar to the reception functions at the first communication device 450 described in the transmission from the second communication device 410 to the first communication device 450. Each receiver 418 receives a radio frequency signal through its corresponding antenna 420, converts the received radio frequency signal into a baseband signal, and provides the baseband signal to the multi-antenna reception processor 472 and the reception processor 470. The reception processor 470 and the multi-antenna reception processor 472 jointly implement the functions of the L1 layer. The controller / processor 475 implements the L2 layer functions. The controller / processor 475 can be associated with a memory 476 that stores program codes and data. The memory 476 can be referred to as a computer-readable medium. In the transmission from the first communication device 450 to the second communication device 410, the controller / processor 475 provides multiplexing between transport and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover the upper layer data packets from the first communication device 450. The upper layer data packets from the controller / processor 475 may be provided to the core network or all protocol layers above the L2 layer, and various control signals may also be provided to the core network or L3 for L3 processing.

[0284] As an embodiment, the first communication device 450 apparatus includes: at least one processor and at least one memory, the at least one memory including computer program code; the at least one memory and the computer program code are configured to be used together with the at least one processor, and the first communication device 450 apparatus at least: receives a first signaling on a first cell, the first signaling indicating a second cell; in response to receiving the first signaling, sends a first random access sequence on the second cell and starts evaluating whether a first condition set for the second cell is met; monitors a first timing advance, the first timing advance is for the first random access sequence; wherein, whether to monitor the first timing advance on the first cell or the second cell depends at least on whether the first condition set is met; when the first condition set is not met, monitors the first timing advance on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

[0285] As an embodiment, the first communication device 450 apparatus includes: a memory storing a computer-readable instruction program, wherein the computer-readable instruction program generates actions when executed by at least one processor, the actions including: receiving a first signaling on a first cell, the first signaling indicating a second cell; in response to receiving the first signaling, sending a first random access sequence on the second cell and starting to evaluate whether a first condition set for the second cell is met; monitoring a first timing advance, the first timing advance being for the first random access sequence; wherein, monitoring the first timing advance on the first cell or the second cell depends at least on whether the first condition set is met; when the first condition set is not met, monitoring the first timing advance on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

[0286] As an embodiment, the second communication device 410 device includes: at least one processor and at least one memory, the at least one memory includes computer program code; the at least one memory and the computer program code are configured to be used together with the at least one processor. The second communication device 410 device at least: sends a first signaling on a first cell, the first signaling indicating a second cell; wherein, as a response to the first signaling being received, a first random access sequence is sent on the second cell, and begins to be evaluated for whether a first condition set of the second cell is satisfied; a first timing advance is monitored, the first timing advance is for the first random access sequence; whether the first timing advance is monitored on the first cell or the second cell depends at least on whether the first condition set is satisfied; when the first condition set is not satisfied, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold;

[0287] or,

[0288] A first random access sequence is received on a second cell; wherein a first signaling is received on the first cell, the first signaling indicating the second cell; as a response to the first signaling being received, the first random access sequence is sent and an evaluation is started on whether a first condition set of the second cell is satisfied; a first timing advance is monitored, the first timing advance being for the first random access sequence; whether the first timing advance is monitored on the first cell or on the second cell depends at least on whether the first condition set is satisfied; when the first condition set is not satisfied, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

[0289] As an embodiment, the second communication device 410 apparatus includes: a memory storing a computer-readable instruction program, wherein the computer-readable instruction program generates an action when executed by at least one processor, wherein the action includes: sending a first signaling on a first cell, wherein the first signaling indicates a second cell; wherein, as a response to the first signaling being received, a first random access sequence is sent on the second cell, and begins to be evaluated for whether a first condition set of the second cell is satisfied; a first timing advance is monitored, wherein the first timing advance is for the first random access sequence; whether the first timing advance is monitored on the first cell or on the second cell depends at least on whether the first condition set is satisfied; when the first condition set is not satisfied, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold;

[0290] or,

[0291] A first random access sequence is received on a second cell; wherein a first signaling is received on the first cell, the first signaling indicating the second cell; as a response to the first signaling being received, the first random access sequence is sent and an evaluation is started on whether a first condition set of the second cell is satisfied; a first timing advance is monitored, the first timing advance being for the first random access sequence; whether the first timing advance is monitored on the first cell or on the second cell depends at least on whether the first condition set is satisfied; when the first condition set is not satisfied, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

[0292] As an embodiment, the first communication device 450 corresponds to the first node in this application.

[0293] As an embodiment, the second communication device 410 corresponds to the second node in this application.

[0294] As an embodiment, the first communication device 450 is a UE.

[0295] As an embodiment, the first communication device 450 is a relay.

[0296] As an embodiment, the second communication device 410 is a base station device.

[0297] As an embodiment, the second communication device 410 is a distribution unit of a base station.

[0298] As an embodiment, the second communication device 410 is a piece of code in a distributed unit of a base station.

[0299] As an embodiment, at least one of the antenna 420, the transmitter 418, the multi-antenna transmit processor 471, the transmit processor 416 or the controller / processor 475 is used to send the first signaling in the present application.

[0300] As an embodiment, at least one of the antenna 452, the receiver 454, the multi-antenna receiving processor 458, the receiving processor 456 or the controller / processor 459 is used to receive the first signaling in the present application.

[0301] As an embodiment, at least one of the antenna 452, the transmitter 454, the multi-antenna transmit processor 457, the transmit processor 468 or the controller / processor 459 is used to send the first random access sequence in the present application.

[0302] As an embodiment, at least one of the antenna 420, the receiver 418, the multi-antenna reception processor 472, the reception processor 470 or the controller / processor 475 is used to receive the first random access sequence in the present application.

[0303] As an embodiment, at least one of the antenna 452, the transmitter 454, the multi-antenna transmit processor 457, the transmit processor 468 or the controller / processor 459 is used to send the second random access sequence in the present application.

[0304] As an embodiment, at least one of the antenna 420, the receiver 418, the multi-antenna receiving processor 472, the receiving processor 470 or the controller / processor 475 is used to receive the second random access sequence in the present application.

[0305] As an embodiment, at least one of the antenna 420, the transmitter 418, the multi-antenna transmit processor 471, the transmit processor 416 or the controller / processor 475 is used to send the first timing advance in the present application.

[0306] As an embodiment, at least one of the antenna 452, the receiver 454, the multi-antenna reception processor 458, the reception processor 456 or the controller / processor 459 is used to receive the first timing advance in the present application.

[0307] As an embodiment, at least one of the antenna 452, the transmitter 454, the multi-antenna transmit processor 457, the transmit processor 468 or the controller / processor 459 is used to send the first wireless signal in the present application.

[0308] As an embodiment, at least one of the antenna 420, the receiver 418, the multi-antenna receiving processor 472, the receiving processor 470 or the controller / processor 475 is used to receive the first wireless signal in the present application.

[0309] Example 5

[0310] Embodiment 5 illustrates a wireless signal transmission flow chart according to an embodiment of the present application, as shown in the attached Figure 5 As shown in the attached Figure 5In the example, the first node N51 and the first transmitter N52 communicate through the first cell, and the first node N51 and the second processor N53 communicate through the second cell. It is particularly noted that the order in this example does not limit the signal transmission order and implementation order in this application. Embodiment 5 is applicable to the scenario where the first condition set is not satisfied. The steps in the dotted box F51 are optional.

[0311] for First node N51 , receiving a first signaling on a first cell in step S511; sending a first random access sequence on a second cell in step S512; starting a first time window in step S513; evaluating whether a first condition set for the second cell is satisfied in step S514; determining that the first condition set for the second cell is not satisfied in step S515; and monitoring a first timing advance in the first cell in step S516. It should be noted that the execution order of steps S512 / S513 and step S514 can be interchanged.

[0312] for First transmitter N52 In step S521, a first signaling is sent on the first cell; and in step S522, a first timing advance is sent on the first cell. Step S522 is optional.

[0313] for Second processor N53 , in step S531, a first random access sequence is received on the second cell.

[0314] In Example 5, a first signaling is received on a first cell, and the first signaling indicates a second cell; as a response to receiving the first signaling, a first random access sequence is sent on the second cell and evaluation of whether a first condition set for the second cell is met is started; as a response to sending the first random access sequence, a first time window is started; it is evaluated and determined that the first condition set is not met, and the first timing advance is monitored on the first cell; the first timing advance is for the first random access sequence; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

[0315] As an embodiment, the first node N51 communicates with the first transmitter N52 through the first cell.

[0316] As an embodiment, the first node N51 communicates with the second processor N53 through the second cell.

[0317] As an embodiment, the first transmitter N52 and the second processor N53 belong to the same gNB-DU (Distributed Unit).

[0318] As an embodiment, the first transmitter N52 and the second processor N53 belong to two different gNB-DUs respectively, and the two different gNB-DUs are associated with the same gNB-CU (Central Unit).

[0319] As an embodiment, the first transmitter N52 and the second processor N53 belong to two different gNB-DUs respectively, and the two different gNB-DUs are associated with two different gNB-CUs.

[0320] As an embodiment, the first transmitter N52 and the second processor N53 belong to the same base station.

[0321] As an embodiment, the first transmitter N52 and the second processor N53 belong to different base stations.

[0322] As an embodiment, a base station includes a gNB-CU and at least one gNB-DU associated with the gNB-CU, and the gNB-CU is connected to any gNB-DU of the at least one gNB-DU through an F1 interface.

[0323] As an embodiment, the first transmitter N52 belongs to the base station of the first cell; the second processor N53 belongs to the base station of the second cell.

[0324] As an embodiment, the base station of the first cell and the base station of the second cell are the same base station.

[0325] As an embodiment, the base station of the first cell and the base station of the second cell are different base stations.

[0326] As an embodiment, a first time window starts as a response to sending the first random access sequence.

[0327] As an embodiment, the first time window is implemented by a first timer, and starting the first time window means starting the first timer.

[0328] As an embodiment, the first time window is maintained at the MAC sublayer of the first node.

[0329] As an embodiment, the expiration value of the first time window includes a positive integer number of time slots.

[0330] As an embodiment, the expiration value of the first time window is configured by the network.

[0331] As an embodiment, whether to monitor the first timing advance in the first cell or the second cell depends not only on whether the first condition set is satisfied, but also on whether the first time window expires.

[0332] As an embodiment, whether to monitor the first timing advance in the first cell or the second cell is determined according to whether the first condition set is satisfied and whether the first time window expires.

[0333] As a sub-embodiment of the above embodiment, when the first condition set is not satisfied, the first timing advance is monitored on the first cell regardless of whether the first time window expires.

[0334] As an embodiment, when the base station of the first cell and the base station of the second cell are different base stations, the first timing advance is obtained at the base station of the second cell, and then forwarded to the base station of the first cell through a backhaul network (backhaul), and sent to the first node by the first transmitter N52 through the first cell.

[0335] As a sub-embodiment of the above embodiment, the above method can reduce the communication interruption time with the first cell by not receiving the first timing advance in the second cell.

[0336] As an embodiment, when the base station of the first cell and the base station of the second cell are different base stations, the candidate cell configuration of the second cell is configured by the base station of the second cell, and then forwarded to the base station of the first cell through the backhaul network, and sent to the first node by the first transmitter N52 through the first cell.

[0337] As an embodiment, when the base station of the first cell and the base station of the second cell are different base stations, the first random access sequence is configured by the base station of the second cell, and then forwarded to the base station of the first cell through the backhaul network, and sent to the first node by the first transmitter N52 through the first cell.

[0338] As an embodiment, when the base station of the first cell and the base station of the second cell are different base stations, the base station of the second cell determines the base station of the serving cell of the sender of the first random access sequence according to the received first random access sequence.

[0339] As an embodiment, the backhaul network is ideal.

[0340] As an embodiment, the backhaul network is non-ideal.

[0341] Example 6

[0342] Embodiment 6 illustrates a wireless signal transmission flow chart according to an embodiment of the present application, as shown in the attached Figure 6 As shown in the attached Figure 6 In the embodiment, the first node N61 and the first transmitter N62 communicate through the first cell, and the first node N61 and the second processor N63 communicate through the second cell. It is particularly noted that the order in this example does not limit the signal transmission order and the implementation order in this application. Embodiment 6 is applicable to the scenario where the first condition set for the second cell is satisfied and the first time window has not expired before the first timing advance is monitored on the first cell. The steps in the dotted box F61 are optional.

[0343] for First node N61 , receiving a first signaling on a first cell in step S611; sending a first random access sequence on a second cell in step S612; starting a first time window in step S613; evaluating whether a first condition set for the second cell is satisfied in step S614; determining in step S615 that the first condition set for the second cell is satisfied and the first time window has not expired; and monitoring a first timing advance on the second cell in step S616. It should be noted that the execution order of steps S612 / S613 and step S614 can be interchanged.

[0344] for First transmitter N62 , in step S621, a first signaling is sent on the first cell.

[0345] for Second processor N63 In step S631, a first random access sequence is received on the second cell; and in step S632, a first timing advance is sent on the second cell. Step S632 is optional.

[0346] In Example 6, a first signaling is received on a first cell, and the first signaling indicates a second cell; as a response to receiving the first signaling, a first random access sequence is sent on the second cell and an evaluation is started as to whether a first condition set for the second cell is met; as a response to sending the first random access sequence, a first time window is started; it is evaluated and determined that the first condition set is met and the first time window has not expired, and the first timing advance is monitored on the second cell; the first timing advance is for the first random access sequence; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

[0347] As an embodiment, the relationship between the first transmitter N62 and the second processor N63 may be referred to the description in Embodiment 5, which will not be repeated here.

[0348] As an embodiment, before evaluating and determining that the first condition set is satisfied, the first timing advance is not monitored on the first cell.

[0349] As an embodiment, determining whether to listen to the first timing advance on the first cell or the second cell according to whether the first condition set is met and whether the first time window expires includes: when the first condition set is met, whether to listen to the first timing advance on the second cell depends on whether the first time window expires.

[0350] As an embodiment, when the first condition set is met and the first time window has not expired, the first timing advance is monitored on the second cell; wherein the first timing advance is not received from the first cell before the first condition set is met.

[0351] As an embodiment, when monitoring the first timing advance on the second cell, the CRC of the PDCCH for the first timing advance is scrambled by RA (Random Access)-RNTI.

[0352] As an embodiment, when the first timing advance is sent in the second cell, the first timing advance is carried in the RAR.

[0353] As an embodiment, the first time window indicates a maximum duration of monitoring the first timing advance on the second cell.

[0354] As an embodiment, the first time window is a random access response window (ra-ResponseWindow).

[0355] As an embodiment, when the first condition set is met and the first timing advance is received on the second cell before the first time window expires, the first wireless signal is sent on the second cell; wherein the first timing advance is not received from the first cell before the first condition set is met; and the first wireless signal is dynamically scheduled.

[0356] As an embodiment, when the first condition set is met and the first timing advance is not received on the second cell before the first time window expires, a second random access sequence is sent in the second cell after the backoff time; wherein the first timing advance is not received from the first cell before the first condition set is met.

[0357] As a sub-embodiment of the above embodiment, the first receiver receives a RAR on the second cell in the first time window, the RAR includes a backoff indicator, and the backoff time is a time randomly selected from 0 and a time determined by the backoff indicator.

[0358] As an embodiment, sending the second random access sequence belongs to a 4-step random access process.

[0359] As an embodiment, when the first condition set is met, the first time window has expired, and the first timing advance is not monitored on the second cell.

[0360] As an embodiment, the first processor, when the first condition set is met, the first time window has expired, and sends a second random access sequence in the second cell; wherein the first timing advance is not received from the first cell before the first condition set is met.

[0361] As an embodiment, the first signaling indicates the air interface resources for sending the second random access sequence.

[0362] As a sub-embodiment of the above embodiment, the first signaling includes a RACH (Random Access CHannel)-ConfigDedicated (dedicated configuration) field.

[0363] As a sub-embodiment of the above embodiment, the first signaling includes a UL / SUL indication.

[0364] As a sub-embodiment of the above embodiment, the first signaling includes an SS / PBCH index.

[0365] As a sub-embodiment of the above embodiment, the first signaling includes a PRACH mask index.

[0366] As a sub-embodiment of the above embodiment, the first signaling includes an index of the second random access sequence.

[0367] As an embodiment, the second random access sequence has the same characteristics as the first random access sequence.

[0368] As an embodiment, the second random access sequence is the same as the first random access sequence.

[0369] As an embodiment, the second random access sequence is a random access sequence other than the first random access sequence.

[0370] As an embodiment, the second random access sequence is reserved for conditional LTM cell switching of the first node.

[0371] As an embodiment, the second random access sequence is dedicated to the first node.

[0372] As an embodiment, the second random access sequence is selected from at least one contention-based random access sequence.

[0373] As an embodiment, the sending of the second random access sequence belongs to a 4-step random access process.

[0374] As an embodiment, the sending of the second random access sequence belongs to a 2-step random access process.

[0375] As an embodiment, the random access process to which the second random access sequence belongs is contention-based.

[0376] As an embodiment, the random access process to which the second random access sequence belongs is contention-free.

[0377] As an embodiment, when monitoring the first timing advance on the second cell, the CRC of the PDCCH for the first timing advance is scrambled by a C-RNTI, and the C-RNTI is configured by a base station of the second cell.

[0378] As an embodiment, the first processor, in response to the first set of conditions being met, stops a first set of operations; wherein the first set of operations includes at least one of monitoring PDCCH (Physical Downlink Control Channel) on the first cell, monitoring PDCCH used to schedule the first cell, and sending PRACH (Physical Random Access Channel) on the first cell.

[0379] As an embodiment, the phrase monitoring PDCCH on the first cell includes: monitoring PDCCH on air interface resources of the first cell.

[0380] As an embodiment, the phrase monitoring a PDCCH used to schedule the first cell includes: monitoring a PDCCH, wherein the PDCCH is used to schedule air interface resources of the first cell.

[0381] As an embodiment, the phrase sending PRACH on the first cell includes: sending PRACH on air interface resources of the first cell.

[0382] As an embodiment, the behavior of stopping the first operation set includes: not monitoring PDCCH in the first cell.

[0383] As an embodiment, the behavior of stopping the first operation set includes: not monitoring PDCCH for the first cell.

[0384] As an embodiment, the behavior of stopping the first operation set includes: not monitoring the PDCCH used to schedule the first cell.

[0385] As an embodiment, the behavior of stopping the first operation set includes: not sending RACH (Random Access CHannel) on the first cell.

[0386] As an embodiment, the behavior of stopping the first operation set includes: not sending PRACH on the first cell.

[0387] As an embodiment, the behavior of stopping the first operation set includes: stopping the sending of HARQ (Hybrid Automatic Repeat Request)-ACK (ACKnowledgement) associated with the first cell.

[0388] As an embodiment, the behavior of stopping the first operation set includes: not sending UL-SCH (Uplink Shared Channel) in the first cell.

[0389] As an embodiment, the behavior of stopping the first operation set includes: not sending PUCCH (Physical Uplink Control Channel) in the first cell.

[0390] As an embodiment, the behavior of stopping the first operation set includes: detaching from the first cell.

[0391] As an embodiment, the behavior of stopping the first operation set includes: releasing air interface resources of the first cell and clearing the configuration for the first cell.

[0392] As an embodiment, the behavior of stopping the first operation set includes: releasing air interface resources of the first cell and saving the configuration for the first cell.

[0393] As an embodiment, the first processor, in response to the first set of conditions being met, begins applying the candidate cell configuration for the second cell.

[0394] As an embodiment, the first processor, in response to the first set of conditions being satisfied, starts a second set of operations; wherein the second set of operations includes at least one of monitoring PDCCH (Physical Downlink Control Channel) on the second cell, monitoring PDCCH used to schedule the second cell, and sending PRACH (Physical Random Access Channel) on the second cell.

[0395] As an embodiment, after the first set of conditions is met, the second cell becomes the service cell of the first node.

[0396] Example 7

[0397] Embodiment 7 illustrates a wireless signal transmission flow chart according to an embodiment of the present application, as shown in the attached Figure 7 As shown in the attached Figure 7 In the embodiment, the first node N71 and the first transmitter N72 communicate through the first cell, and the first node N71 and the second processor N73 communicate through the second cell. It is particularly noted that the order in this example does not limit the signal transmission order and implementation order in this application. Embodiment 7 is applicable to the scenario where the first timing advance is received on the first cell.

[0398] for First node N71 In step S711, the first condition set for the second cell is not met, and the first timing advance is monitored on the first cell; in step S712, the first timing advance is received on the first cell; in step S713, the second time window is started; in step S714, it is determined that the first condition set for the second cell is met when the second time window is running; in step S715, a first wireless signal is sent on the second cell when the second time window is running.

[0399] for First transmitter N72 , in step S721, a first timing advance is sent on the first cell.

[0400] for Second processor N73 , in step S731, a first wireless signal is received on the second cell.

[0401] In Example 7, the first timing advance is received on the first cell, and a second time window is started as a response to receiving the first timing advance on the first cell; it is determined that the first condition set is satisfied when the second time window is running; as a response to the first condition set being satisfied when the second time window is running, a first wireless signal is sent on the second cell when the second time window is running; wherein the first timing advance is applied to the first wireless signal; and the first wireless signal carries the first uplink data.

[0402] As an embodiment, the relationship between the first transmitter N72 and the second processor N73 may be referred to the description in Embodiment 5, which will not be repeated here.

[0403] As an embodiment, a second time window is started in response to receiving the first timing advance on the first cell; wherein the first condition set is not met before the first timing advance is received on the first cell.

[0404] As an embodiment, after receiving the first timing advance on the first cell, continue to evaluate whether the first condition set for the second cell is met.

[0405] As an embodiment, after receiving the first timing advance on the first cell, if the first time window has not expired, the first time window is stopped.

[0406] As an embodiment, after receiving the first timing advance on the first cell, if the first time window has not expired, continue to run the first time window.

[0407] As an embodiment, the second time window is implemented by a second timer, and starting the second time window means starting the second timer.

[0408] As an embodiment, the second time window is maintained at the MAC sublayer of the first node.

[0409] As an embodiment, the second time window indicates a duration for which the first node considers (considers) uplink time alignment (uplink time aligned) with the second cell.

[0410] As an embodiment, the expiration value of the second time window is configured by the network.

[0411] As an embodiment, the expiration value of the second time window is determined by the UE itself.

[0412] As an embodiment, the expiration value of the second time window includes a positive integer number of milliseconds (ms).

[0413] As an embodiment, the reception time of the first timing advance on the first cell is earlier than the time when the first condition set for the second cell is satisfied.

[0414] As an embodiment, the first set of conditions for the second cell is met when the second time window runs.

[0415] As an embodiment, in response to the first set of conditions for the second cell being met when the second time window is running, a first wireless signal is sent on the second cell when the second time window is running.

[0416] As an embodiment, the first wireless signal is sent only when the second time window is running.

[0417] As an embodiment, the first wireless signal is sent via PUSCH.

[0418] As an embodiment, the first wireless signal is the first wireless signal sent through PUSCH on the second cell.

[0419] As an embodiment, the first wireless signal is not sent via PRACH.

[0420] As an embodiment, the air interface resources occupied by the first wireless signal are preconfigured.

[0421] As an embodiment, the air interface resources occupied by the first wireless signal belong to an uplink configured grant (uplink configured grant).

[0422] As a sub-embodiment of the above two embodiments, when the base station of the first cell and the base station of the second cell are different base stations, the air interface resources occupied by the first wireless signal are configured by the base station of the second cell, and then forwarded to the base station of the first cell through the backhaul network, and sent to the first node through the first cell.

[0423] As an embodiment, the air interface resources occupied by the first wireless signal are scheduled by monitoring the PDCCH for the second cell.

[0424] As an embodiment, the air interface resources occupied by the first wireless signal are scheduled by the PDCCH monitored on the second cell.

[0425] As an embodiment, the air interface resources include at least one of time domain resources, frequency domain resources, code domain resources or space domain resources.

[0426] As an embodiment, the first wireless signal is the first wireless signal sent on the second cell after the first set of conditions is met.

[0427] As an embodiment, the first wireless signal carries the first uplink data.

[0428] As an embodiment, all or part of the bits included in the first uplink data are used to generate the first wireless signal.

[0429] As an embodiment, all or part of the bits included in the first uplink data are sequentially subjected to CRC calculation (CRC Calculation), channel coding (Channel Coding), rate matching (Rate matching), scrambling (Scrambling), modulation (Modulation), layer mapping (Layer Mapping), antenna port mapping (Antenna PortMapping), mapping to virtual resource blocks (Mapping to Virtual Resource Blocks), mapping from virtual resource blocks to physical resource blocks (Mapping from Virtual to Physical Resource Blocks), OFDM baseband signal generation (OFDM Baseband Signal Generation), and modulation upconversion (Modulation and Upconversion) to obtain the first wireless signal.

[0430] As an embodiment, the first uplink data is a MAC sublayer message, or a message other than a physical layer message.

[0431] As an embodiment, the first uplink data belongs to SRB (Signaling Radio Bearer).

[0432] As an embodiment, the first uplink data belongs to DRB (Data Radio Bearer).

[0433] As an embodiment, the first uplink data belongs to MRB (MBS Radio Bearer, multicast broadcast service radio bearer).

[0434] As an embodiment, the first uplink data is RRCReconfigurationComplete (RRC configuration completed).

[0435] As an embodiment, the first timing advance is applied to the first wireless signal.

[0436] As an embodiment, the first timing advance being applied to the first wireless signal includes: the advance value indicated by the first timing advance being used for uplink timing of sending the first wireless signal.

[0437] As an embodiment, the first timing advance is applied to the first wireless signal and includes: the first timing advance indicates an advance value of the start time of the uplink time unit for sending the first wireless signal relative to the corresponding downlink time unit.

[0438] As a sub-embodiment of the above embodiment, the time unit is a frame, a subframe or a time slot.

[0439] As an embodiment, the first node obtains the downlink synchronization of the second cell according to the downlink synchronization signal; the advance value of the first timing advance indication is t; if the uplink transmission time slot of the first wireless signal is n, the first node starts sending the first wireless signal at a time t before the start time of the corresponding downlink time slot n.

[0440] As an embodiment, the advance value of the first timing advance indication is related to the subcarrier of the first wireless signal.

[0441] As an embodiment, the advance value of the first timing advance indication is N TA =T A ·16·64 / 2 μ ; wherein the T A is the index included in the first timing advance, the 2 μ •15kHz (kilohertz) is the subcarrier spacing (SCS) of the second cell.

[0442] As an example, the T A A positive integer less than 4096.

[0443] As an example, the T A The value of is 0,1,2,...,3846.

[0444] As an embodiment, μ is a positive integer not greater than 10.

[0445] As an embodiment, the value of μ is 0, 1, 2, 3, 4, 5, 6.

[0446] As an embodiment, the first set of conditions is not met when the second time window is running, and the second random access sequence is sent on the second cell in response to the expiration of the second time window.

[0447] As an embodiment, the above method can obtain uplink synchronization in the second cell in advance and reduce the cell switching delay.

[0448] As an embodiment, when the second time window is running, the first condition set is met and the first uplink data is not successfully sent, and as a response to the expiration of the second time window, a second random access sequence is sent on the second cell.

[0449] As an embodiment, the above method can reduce the cell switching delay by sending the second random access sequence in time.

[0450] As an embodiment, after the first wireless signal is sent, the PDCCH is not received on the service cell of the first node, and the first uplink data is not successfully sent.

[0451] As an embodiment, after sending the first wireless signal, a PDCCH is received on the service cell of the first node, the PDCCH indicates a downlink assignment and the PDCCH does not indicate a new transmission, and the first uplink data is not successfully sent.

[0452] As an embodiment, after sending the first wireless signal, a PDCCH is received on the service cell of the first node, the PDCCH indicates an uplink grant (uplink grant) and the PDCCH does not indicate a new transmission (new transmission), and the first uplink data is not successfully sent.

[0453] As an embodiment, after sending the first wireless signal, a PDCCH is received on the service cell of the first node, the PDCCH indicates an uplink grant and the PDCCH does not indicate the same HARQ process as the first wireless signal, and the first uplink data is not successfully sent.

[0454] Example 8

[0455] Embodiment 8 illustrates a schematic diagram of monitoring the first timing advance on the second cell according to an embodiment of the present application, as shown in the attached figure. Figure 8 shown.

[0456] As an embodiment, monitoring the first timing advance on the second cell includes receiving the first timing advance on the time-frequency resources indicated by the first configured downlink allocation.

[0457] As an embodiment, a wireless signal occupying time-frequency resources indicated by the first configuration downlink allocation is sent through a PDSCH, and the PDSCH carries the first timing advance.

[0458] As a sub-embodiment of the above two embodiments, the first timing advance is carried in a MAC CE.

[0459] As an embodiment, the time-frequency resources indicated by the first configured downlink allocation are pre-configured.

[0460] As an embodiment, the first configured downlink allocation is one of multiple configured downlink allocations.

[0461] As an embodiment, the first timing advance is sent in at least one configured downlink allocation, and the at least one configured downlink allocation includes the first configured downlink allocation.

[0462] As an embodiment, the second processor, in response to receiving the first random access sequence, activates the first downlink allocation.

[0463] As a sub-embodiment of the above embodiment, the first random access sequence is dedicated to the first node.

[0464] As a sub-embodiment of the above embodiment, the first configured downlink allocation is for the first node.

[0465] As an embodiment, the first downlink allocation indicates the multiple configured downlink allocations.

[0466] As an embodiment, the time intervals between the time domain resources indicated by any two adjacent configured downlink allocations included in the multiple configured downlink allocations are the same; wherein the multiple configured downlink allocations include at least 3 configured downlink allocations.

[0467] As an embodiment, the frequency domain resources indicated by any two configured downlink allocations included in the multiple configured downlink allocations are the same.

[0468] As an embodiment, the first downlink allocation is semi-persistent scheduling.

[0469] As an embodiment, the first downlink allocation is a type 1 configured downlink allocation.

[0470] As an embodiment, the first downlink allocation is a type 2 configured downlink allocation.

[0471] As an embodiment, the first signaling configures the first downlink allocation.

[0472] As an embodiment, the first signaling includes configuration information of the first downlink allocation.

[0473] As an embodiment, the configuration information of the first downlink allocation is determined by the base station of the second cell, and then sent to the base station of the first cell through the backhaul network, and sent to the first node through the first cell.

[0474] As an embodiment, the configuration information of the first downlink allocation includes the frequency domain resources indicated by the multiple configured downlink allocations.

[0475] As an embodiment, the configuration information of the first downlink allocation includes the time domain resources indicated by the multiple configured downlink allocations.

[0476] As an embodiment, the configuration information of the first downlink allocation includes the HARQ processes indicated by the multiple configured downlink allocations.

[0477] As an embodiment, the configuration information of the first downlink allocation includes the MCS (Modulation and Coding Scheme, modulation and coding scheme) indicated by the multiple configuration downlink allocations.

[0478] As an embodiment, the first downlink allocation is deactivated when the first time window expires.

[0479] As an embodiment, the first time window indicates the maximum duration during which the first timing advance is valid.

[0480] As an embodiment, the second node maintains the first time window.

[0481] As an embodiment, after receiving the first timing advance, the first downlink allocation is deactivated.

[0482] As an embodiment, after receiving the first timing advance, whether the first downlink allocation is deactivated is determined by the network.

[0483] In the attached figure of Example 8, the first downlink allocation is activated after the first random access sequence is received, the first downlink allocation indicates the multiple configured downlink allocations, and the first configured downlink allocation is one of the multiple configured downlink allocations.

[0484] Example 9

[0485] Embodiment 9 illustrates a structural block diagram of a processing device in a first node according to an embodiment of the present application, as shown in the attached figure. Fig. 9 As shown in the attached Fig. 9 In the embodiment, the first node processing device 9 includes a first receiver 901 and a first processor 902; the first node 900 is a UE.

[0486] In Example 9, a first receiver 901 receives a first signaling on a first cell, wherein the first signaling indicates a second cell; a first processor 902, in response to receiving the first signaling, sends a first random access sequence on the second cell and starts to evaluate whether a first condition set for the second cell is met; monitors a first timing advance, wherein the first timing advance is for the first random access sequence; wherein whether the first timing advance is monitored on the first cell or the second cell depends at least on whether the first condition set is met; when the first condition set is not met, monitors the first timing advance on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

[0487] As an embodiment, the first processor 902, in response to sending the first random access sequence, starts a first time window; wherein, whether to monitor the first timing advance in the first cell or the second cell depends on whether the first time window expires; when the first condition set is met and the first time window has not expired, the first timing advance is monitored in the second cell; and the first timing advance is not received from the first cell before the first condition set is met.

[0488] As an embodiment, the first processor 902, in response to receiving the first timing advance on the first cell, starts a second time window; wherein the first condition set is not satisfied before receiving the first timing advance on the first cell.

[0489] As an embodiment, the first processor 902, in response to receiving the first timing advance on the first cell, starts a second time window; wherein the first condition set is not met before receiving the first timing advance on the first cell; the first processor 902, in response to the first condition set being met when the second time window is running, sends a first wireless signal on the second cell when the second time window is running; wherein the first timing advance is applied to the first wireless signal; the first wireless signal carries the first uplink data.

[0490] As an embodiment, the first processor 902, in response to receiving the first timing advance on the first cell, starts a second time window; wherein the first condition set is not met before receiving the first timing advance on the first cell; the first processor 902, in response to the first condition set being met when the second time window is running, sends a first wireless signal on the second cell when the second time window is running; wherein the first timing advance is applied to the first wireless signal; the first wireless signal carries the first uplink data; the first processor 902, in response to the expiration of the second time window, sends a second random access sequence on the second cell; wherein the first condition set is not met when the second time window is running, or, when the second time window is running, the first condition set is met and the first uplink data is not successfully sent.

[0491] As an embodiment, monitoring the first timing advance on the second cell includes receiving the first timing advance on time-frequency resources indicated by a first configured downlink allocation; wherein the first configured downlink allocation is one of multiple configured downlink allocations.

[0492] As an embodiment, monitoring the first timing advance on the second cell includes receiving the first timing advance on the time-frequency resources indicated by the first configured downlink allocation; wherein the first configured downlink allocation is one of multiple configured downlink allocations; as a response to the first random access sequence being received, the first downlink allocation is activated, and the first downlink allocation indicates the multiple configured downlink allocations; wherein the first signaling configures the first downlink allocation.

[0493] As an embodiment, after receiving RRCReconfiguration, a preamble is sent on the second cell and evaluation of whether the first condition set for the second cell is met is started, the first condition set indicating the condition for conditional switching; after the second cell sends the preamble, a random access response window is started; when the first condition set for the second cell is not met, regardless of whether the random access response window expires, TA (timing advance) is monitored on the first cell and the TA is received; as a response to receiving the TA, TAT (timeAlginmentTimer) is started and evaluation of whether the first condition set is met continues.

[0494] As a sub-embodiment of the above embodiment, when the TAT is running and the first condition set is satisfied, a PUSCH is sent while the TAT is running, and the PUSCH carries RRCReconfigurationComplete.

[0495] As a sub-embodiment of the above embodiment, when the TAT is running and the first condition set is met, a PUSCH is sent when the TAT is running, and the PUSCH carries RRCReconfigurationComplete; if the RRCReconfigurationComplete is not successfully sent and the TAT expires, a preamble is sent on the second cell.

[0496] As a sub-embodiment of the above embodiment, when the TAT is running and the first condition set is not satisfied, a preamble is sent on the second cell as a response to the TAT expiration.

[0497] The received RRCReconfiguration signaling in the above embodiment can be implemented through other signaling, such as MAC CE, which can reduce the cell switching delay.

[0498] As an embodiment, after receiving RRCReconfiguration, a preamble is sent on the second cell and evaluation is started on whether the first condition set for the second cell is met, the first condition set indicating the condition for conditional switching; after the second cell sends the preamble, a random access response window is started; when the TA is not monitored on the first cell and the first condition set for the second cell is met, if the random access response window has not expired, the TA continues to be monitored on the second cell; if the random access response window has expired, a preamble is sent on the second cell.

[0499] As an embodiment, the first receiver 901 includes the attached Figure 4 The receiver 454 (including antenna 452), receive processor 456, multi-antenna receive processor 458 and controller / processor 459.

[0500] As an embodiment, the first receiver 901 includes the attached Figure 4 At least one of the receiver 454 (including antenna 452), the receive processor 456, the multi-antenna receive processor 458 or the controller / processor 459.

[0501] As an embodiment, the first processor 901 includes the attached Figure 4 The receiver 454 (including antenna 452), receive processor 456, multi-antenna receive processor 458 and controller / processor 459.

[0502] As an embodiment, the first processor 901 includes the attached Figure 4 At least one of the receiver 454 (including antenna 452), the receive processor 456, the multi-antenna receive processor 458 or the controller / processor 459.

[0503] As an embodiment, the first processor 901 includes the attached Figure 4 The transmitter 454 (including antenna 452), transmit processor 468, multi-antenna transmit processor 457 and controller / processor 459.

[0504] As an embodiment, the first processor 901 includes the attached Figure 4 At least one of the receiver 454 (including antenna 452), transmit processor 468, multi-antenna transmit processor 457 or controller / processor 459.

[0505] Example 10

[0506] Embodiment 10 illustrates a structural block diagram of a processing device in a second node according to an embodiment of the present application, as shown in the attached figure. Fig.10 As shown in the attached Fig.10 In the figure, the dotted box indicates that it is optional, the second node processing device 1000 includes a first transmitter 1001, or the second node processing device 1000 includes a second processor 1002, or the second node processing device 1000 includes a first transmitter 1001 and a second processor 1002; the second node 1000 is a base station.

[0507] In embodiment 10, a first transmitter 1001 sends a first signaling on a first cell, wherein the first signaling indicates a second cell; wherein, as a response to the first signaling being received, a first random access sequence is sent on the second cell, and evaluation begins for whether a first condition set of the second cell is satisfied; a first timing advance is monitored, wherein the first timing advance is for the first random access sequence; whether the first timing advance is monitored on the first cell or on the second cell depends at least on whether the first condition set is satisfied; when the first condition set is not satisfied, the first timing advance is monitored on the first cell; the first condition set includes that a channel quality of the first cell is worse than a first threshold;

[0508] or,

[0509] The second processor 1002 receives a first random access sequence on a second cell; wherein, a first signaling is received on the first cell, and the first signaling indicates the second cell; as a response to the first signaling being received, the first random access sequence is sent and an evaluation is started for whether a first condition set of the second cell is satisfied; a first timing advance is monitored, and the first timing advance is for the first random access sequence; whether the first timing advance is monitored on the first cell or the second cell depends at least on whether the first condition set is satisfied; when the first condition set is not satisfied, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

[0510] As an embodiment, the second node includes the first transmitter 1001 and the second processor 1002.

[0511] As an embodiment, as a response to the first random access sequence being sent, a first time window is started; wherein, whether the first timing advance is monitored on the first cell or the second cell depends on whether the first time window expires; when the first condition set is met and the first time window has not expired, the first timing advance is monitored on the second cell; and the first timing advance is not received from the first cell before the first condition set is met.

[0512] As an embodiment, a second time window is started in response to the first timing advance being received on the first cell; wherein the first condition set is not met before the first timing advance is received on the first cell.

[0513] As an embodiment, as a response to the first timing advance being received on the first cell, a second time window is started; wherein the first condition set is not met before the first timing advance is received on the first cell; the second processor 1002 receives a first wireless signal on the second cell; wherein the second time window is in operation and the first condition set is met; wherein the first timing advance is applied to the first wireless signal; and the first wireless signal carries the first uplink data.

[0514] As an embodiment, as a response to the first timing advance being received on the first cell, a second time window is started; wherein the first condition set is not met before the first timing advance is received on the first cell; the second processor 1002 receives a first wireless signal on the second cell; wherein the second time window is in operation and the first condition set is met; wherein the first timing advance is applied to the first wireless signal; the first wireless signal carries the first uplink data; the second processor 1002 receives a second random access sequence on the second cell; wherein the second time window has expired; the first condition set is not met when the second time window is running, or, the first condition set is met and the first uplink data is not successfully received when the second time window is running.

[0515] As an embodiment, the second processor 1002 sends the first timing advance on the time-frequency resources indicated by a first configured downlink allocation; wherein the first configured downlink allocation is one of multiple configured downlink allocations.

[0516] As an embodiment, the second processor 1002 sends the first timing advance on the time-frequency resources indicated by the first configured downlink allocation; wherein the first configured downlink allocation is one of multiple configured downlink allocations; the second processor 1002, as a response to receiving the first random access sequence, activates the first downlink allocation, the first downlink allocation indicating the multiple configured downlink allocations; wherein the first signaling configures the first downlink allocation.

[0517] As an embodiment, the source base station sends RRCReconfiguration on the first cell to configure the first condition set for performing conditional switching on the second cell; in response to receiving the RRCReconfiguration, the receiver of the RRCReconfiguration sends a preamble on the second cell and starts to evaluate whether the first condition set for the second cell is met.

[0518] As a sub-embodiment of the above embodiment, the target base station receives the preamble, obtains the TA according to the preamble, and sends the TA carried in the RAR to the recipient of the RRCReconfiguration through the target cell, i.e., the second cell, when the random access response window is running; wherein the target base station maintains the random access response window.

[0519] The above method is backward compatible and simplifies the implementation.

[0520] As a sub-embodiment of the above embodiment, the target base station receives the preamble, obtains the TA according to the preamble, and activates the configured downlink allocation configured on the target cell, that is, the second cell, and carries the TA in the MAC CE and sends it to the recipient of the RRCReconfiguration on the time-frequency resources indicated by the configured downlink allocation.

[0521] The above method can send the TA on multiple time-frequency resources configured with downlink allocation indications, thereby improving the robustness of TA reception.

[0522] The methods in the above two sub-embodiments effectively support the scenario where the first condition set is satisfied earlier, avoid missed detection of the TA, and improve the robustness of the TA reception.

[0523] As a sub-embodiment of the above embodiment, the target base station receives the preamble, obtains the TA according to the preamble and sends the TA to the source base station; after the source base station receives the TA from the target base station, it sends the TA to the recipient of the RRCReconfiguration through the source cell, that is, the first cell.

[0524] The above method effectively supports the scenario where the first condition set is satisfied later, avoids missed detection of the TA, and improves the robustness of the TA reception.

[0525] As an embodiment, the first transmitter 1001 includes the attached Figure 4 The transmitter 418 (including antenna 420), transmit processor 416, multi-antenna transmit processor 471 and controller / processor 475.

[0526] As an embodiment, the first transmitter 1001 includes the attached Figure 4 At least one of the transmitter 418 (including antenna 420), the transmit processor 416, the multi-antenna transmit processor 471 or the controller / processor 475.

[0527] As an embodiment, the second processor 1002 includes the attached Figure 4 The transmitter 418 (including antenna 420), transmit processor 416, multi-antenna transmit processor 471 and controller / processor 475.

[0528] As an embodiment, the second processor 1002 includes the attached Figure 4 At least one of the transmitter 418 (including antenna 420), the transmit processor 416, the multi-antenna transmit processor 471 or the controller / processor 475.

[0529] As an embodiment, the second processor 1002 includes the attached Figure 4 The receiver 418 (including antenna 420), receive processor 470, multi-antenna receive processor 472 and controller / processor 475.

[0530] As an embodiment, the second processor 1002 includes the attached Figure 4 At least one of the receiver 418 (including the antenna 420), the receive processor 470, the multi-antenna receive processor 472 or the controller / processor 475.

[0531] A person of ordinary skill in the art can understand that all or part of the steps in the above method can be completed by instructing the relevant hardware through a program, and the program can be stored in a computer-readable storage medium, such as a read-only memory, a hard disk or an optical disk. Optionally, all or part of the steps in the above embodiment can also be implemented using one or more integrated circuits. Accordingly, each module unit in the above embodiment can be implemented in the form of hardware or in the form of a software function module, and the present application is not limited to any specific form of software and hardware combination. The first type of communication node or UE or terminal in the present application includes but is not limited to mobile phones, tablet computers, notebooks, Internet cards, low-power devices, eMTC (enhanced Machine Type Communication, enhanced machine type communication) equipment, NB-IoT equipment, vehicle-mounted communication equipment, aircraft, airplanes, drones, remote-controlled aircraft and other wireless communication equipment. The second type of communication node or base station or network side equipment in the present application includes but is not limited to macrocellular base stations, microcellular base stations, home base stations, relay base stations, eNB, gNB, transmission and reception nodes TRP (Transmission and Reception Point, transmission and reception point), relay satellites, satellite base stations, aerial base stations and other wireless communication equipment.

[0532] The above is only a preferred embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A first node used for wireless communication, characterized in that: include: A first receiver receives a first signaling on a first cell, wherein the first signaling indicates a second cell; A first processor, in response to receiving the first signaling, sends a first random access sequence on the second cell and starts evaluating whether a first condition set for the second cell is satisfied; monitors a first timing advance, the first timing advance being for the first random access sequence; Among them, whether to monitor the first timing advance on the first cell or the second cell depends at least on whether the first condition set is met; when the first condition set is not met, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

2. The first node according to claim 1, characterized in that: include: The first processor, in response to sending the first random access sequence, starts a first time window; Among them, whether to monitor the first timing advance in the first cell or the second cell depends on whether the first time window expires; when the first condition set is met and the first time window has not expired, the first timing advance is monitored in the second cell; the first timing advance is not received from the first cell before the first condition set is met.

3. The first node according to claim 1 or 2, characterized in that: include: the first processor, in response to receiving the first timing advance on the first cell, starting a second time window; The first set of conditions is not met before the first timing advance is received on the first cell.

4. The first node according to claim 3, characterized in that: include: The first processor, in response to the first set of conditions being satisfied when the second time window is running, sends a first wireless signal on the second cell when the second time window is running; The first timing advance is applied to the first wireless signal; the first wireless signal carries the first uplink data.

5. The first node according to claim 4, characterized in that: include: The first processor, in response to expiration of the second time window, sends a second random access sequence on the second cell; Wherein, when the second time window is running, the first condition set is not satisfied, or, when the second time window is running, the first condition set is satisfied and the first uplink data is not successfully sent.

6. The first node according to any one of claims 1 to 5, characterized in that: Monitoring the first timing advance on the second cell includes receiving the first timing advance on time-frequency resources indicated by the first configured downlink allocation; The first configured downlink allocation is one of multiple configured downlink allocations.

7. The first node according to claim 6, characterized in that: The first random access sequence is used to activate a first downlink allocation, the first downlink allocation indicating the plurality of configured downlink allocations; The first signaling configures the first downlink allocation.

8. A second node used for wireless communication, characterized in that: include: A first transmitter sends a first signaling on a first cell, wherein the first signaling indicates a second cell; Wherein, as a response to the first signaling being received, a first random access sequence is sent on the second cell, and is evaluated for whether a first condition set of the second cell is satisfied; whether a first timing advance is monitored on the first cell or the second cell depends at least on whether the first condition set is satisfied; when the first condition set is not satisfied, the first timing advance is monitored on the first cell; the first timing advance is for the first random access sequence; the first condition set includes that the channel quality of the first cell is worse than a first threshold; or, A second processor receives a first random access sequence on a second cell; In which, a first signaling is received on a first cell, and the first signaling indicates the second cell; as a response to the first signaling being received, the first random access sequence is sent and an evaluation is started on whether a first condition set for the second cell is met; a first timing advance is monitored, and the first timing advance is for the first random access sequence; whether the first timing advance is monitored on the first cell or the second cell depends at least on whether the first condition set is met; when the first condition set is not met, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

9. The second node according to claim 8, characterized in that: The second node includes the first transmitter and the second processor.

10. A method in a first node for wireless communication, characterized in that: include: receiving a first signaling on a first cell, wherein the first signaling indicates a second cell; In response to receiving the first signaling, sending a first random access sequence on the second cell and starting to evaluate whether a first condition set for the second cell is satisfied; monitoring a first timing advance, the first timing advance being for the first random access sequence; Among them, whether to monitor the first timing advance on the first cell or the second cell depends at least on whether the first condition set is met; when the first condition set is not met, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

11. A method in a second node for wireless communication, characterized in that: include: Sending a first signaling on a first cell, where the first signaling indicates a second cell; Wherein, as a response to the first signaling being received, a first random access sequence is sent on the second cell, and an evaluation is started for whether a first condition set of the second cell is satisfied; a first timing advance is monitored, and the first timing advance is for the first random access sequence; whether the first timing advance is monitored on the first cell or the second cell depends at least on whether the first condition set is satisfied; when the first condition set is not satisfied, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold; or, receiving a first random access sequence on a second cell; In which, a first signaling is received on a first cell, and the first signaling indicates the second cell; as a response to the first signaling being received, the first random access sequence is sent and an evaluation is started on whether a first condition set for the second cell is met; a first timing advance is monitored, and the first timing advance is for the first random access sequence; whether the first timing advance is monitored on the first cell or the second cell depends at least on whether the first condition set is met; when the first condition set is not met, the first timing advance is monitored on the first cell; the first condition set includes that the channel quality of the first cell is worse than a first threshold.

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