WO2021026818A1 - Cell switching method, system and device - Google Patents

Abstract

Provided are a cell switching method, system and device. The method comprises: a user equipment (UE) determining a first uplink sending moment according to a first timing advance value, wherein the first timing advance value is a parameter for communication between the UE and a first network device, the first uplink sending moment is a moment when the UE sends information to the first network device, and the first network device is a network device of a first cell accessed by the UE at present; the UE sending a first random access preamble to a second network device at the first uplink sending moment, wherein the second network device is a network device of a second cell, and the second cell is a target cell of the UE; the UE receiving, from the second network device, a first random access response message responding to the first random access preamble; and the UE maintaining communication with the first network device and the second network device at the same time.

Description

Method, system and equipment for cell handover Technical field

This application relates to the field of wireless communication, and in particular to a method, system and device for cell handover.

Background technique

In a cellular communication system, when a user equipment (User Equipment, UE) moves, a switching of a serving cell may occur according to changes in signal strength or load balancing requirements on the network equipment side. In the traditional handover method, when the UE receives a handover command, the UE will disconnect the radio resource control (Radio Resource Control, RRC) connection with the serving cell, and then start a random access process for the target cell. After sending the handover complete message, the UE resumes the RRC connection. During this handover, the data transmission of the UE is interrupted.

In order to reduce the interruption time of data transmission in the UE handover process, the Make-Before-Break technology is proposed. The main improvement is that when the UE receives the handover command, it does not immediately interrupt the connection with the serving cell, but Continue to maintain until the UE's first uplink transmission time for the target cell. For example, after the UE receives the handover command, the communication with the serving cell is still maintained, and it is not interrupted until the UE sends a random access preamble to the target cell. In this way, during the random access process between the UE and the target cell, the data transmission is interrupted, which reduces the time of data interruption. Furthermore, enhanced Make-Before-Break (eMBB) is proposed, which requires the UE to be connected to two network devices at the same time. Although this method reduces the interruption time of data transmission during the switching process, The UE is required to have two sets of radio frequency chains and two sets of Fast Fourier Transformation (FFT) processors (or two sets of baseband processing units). This greatly increases the cost of the UE and is not conducive to the promotion of this technology.

Summary of the invention

This application provides a method, system and device for cell handover, which can enable a UE with a single radio frequency chain or a single FFT processor to switch cells within a short data transmission interruption time, thereby reducing the cost of the UE while ensuring that the UE performs the cell The shorter data transmission interruption time during handover is beneficial to the promotion of this technology.

In a first aspect, a method for cell handover is provided. The method includes: a user equipment UE determines a first uplink transmission time according to a first timing advance, where the first timing advance is the ratio between the UE and the first network device Parameters for inter-communication, the first uplink sending moment is the moment when the UE sends information to the first network device, and the first network device is the network device of the first cell currently accessed by the UE; Sending, by the UE, a first random access preamble to a second network device at the first uplink sending moment, the second network device is a network device of a second cell, and the second cell is a target cell of the UE; The UE receives a first random access response message in response to the first random access preamble from the second network device; the UE maintains with the first network device and the second network device at the same time Communication.

According to this embodiment of the application, the UE sends the first random access preamble to the second network device at the first uplink moment, where the first uplink moment is the uplink moment when the UE sends information to the first network device, and the UE may be in the same Sending information to the first network device and the second network device at all times can realize the random access process with the second network device while the UE is performing data transmission with the first network device. This method reduces the interruption time of data transmission during the handover process, which can satisfy the requirement that the UE maintains data transmission with the current access cell and the target cell at the same time during the handover process. At the same time, it can also greatly save the cost of the UE.

With reference to the first aspect, in some implementation manners of the first aspect, while sending the first random access preamble, the UE also sends first data information to the first network device.

According to the embodiment of the present application, the UE can simultaneously send information to the first network device and the second network device at the same time, which can implement a random access process with the second network device while the UE and the first network device are performing data transmission. This method reduces the data transmission interruption time during the handover process, and can satisfy the requirement that the UE maintains data transmission with the current access cell and the target cell at the same time during the handover process, and at the same time, it can also greatly save the cost of the UE.

With reference to the first aspect, in some implementations of the first aspect, the method further includes: the UE sends first measurement result information to the first network device, where the first measurement result information is used to indicate the A measurement result of a downlink timing deviation TD and a first downlink power deviation PD, where the first TD is the TD between the first cell and the second cell, and the first PD is the first PD between the cell and the second cell; the UE receives handover instruction information from the first network device, the handover instruction information is used to instruct the UE to perform cell handover, wherein the first TD is less than Or equal to the length of the cyclic prefix CP, and the first PD is less than the first threshold.

According to the embodiment of the application, according to the embodiment of the application, the UE measures the downlink timing deviation and power deviation of the two cells, and reports the measurement results to the network device, as the network device to determine whether to use a single radio frequency chain or a single FFT processor UE The basis for performing eMBB handover. If the measurement result meets the preset condition, the network device can instruct the UE to perform cell handover, and can also maintain data transmission with the currently accessed cell during the handover process. The UE using a single radio frequency chain or a single FFT processor performs eMBB handover, which can satisfy the requirement that the UE maintains data transmission with the current access cell and the target cell at the same time during the handover process. At the same time, it can also greatly save the cost of the UE.

With reference to the first aspect, in some implementations of the first aspect, the method further includes: the UE receiving first measurement indication information sent by the first network device, where the first measurement indication information is used to indicate The UE measures the first TD and the first PD; the UE measures the first TD and the first PD according to the first measurement indication information.

According to the embodiment of the present application, the first network device may send the first measurement indication information to the UE, which may instruct the UE to measure the first TD and the first PD between the first cell and the second cell.

With reference to the first aspect, in some implementations of the first aspect, the method further includes: the UE sending capability information to the first network device, the capability information being used to indicate that the UE is a single fast The inner transform FFT processor or a UE with a single radio frequency link, or the UE has the ability to switch connections at the same time, or the UE has the ability to measure TD and PD.

According to the embodiment of the present application, the UE can report capability information to the first network device according to the actual situation, which can effectively prevent the first network device from sending the first measurement indication information to all UEs. It can be directed to a single FFT processor or a single UE. , Or the UE has the ability to switch connections at the same time, or the UE has the ability to measure TD and PD to send the first measurement indication information to avoid waste of resources.

With reference to the first aspect, in some implementations of the first aspect, the first random access response message includes a second timing advance, and the second timing advance is used to determine the uplink transmission of the UE sending information time.

According to the embodiment of the present application, the second timing advance is the timing advance determined by the second network device according to the first uplink sending moment, and the UE may determine the new uplink sending moment according to the second timing advance. The first uplink transmission time is determined according to the first time advance and the first downlink reception time, and the new uplink transmission time can be determined according to the first downlink transmission time, the first time advance, and the second time advance , The second timing advance can be understood as an increment of the first timing advance.

With reference to the first aspect, in some implementations of the first aspect, the second timing advance is zero, and the method further includes: the UE sends a notification to the second network according to the first timing advance The device sends a handover complete message.

According to the embodiment of the present application, the second TA may be zero, that is, the UE may apply the first TA to establish communication with the second network device, and the UE may send a handover complete message to the second network device according to the first TA. The second TA may not be zero, that is, the UE cannot use the first TA to establish communication with the second network device, and the UE or the first network device or the second network device needs to coordinate the common TA.

It should be understood that when the coordination is unsuccessful, that is, there is no common TA between the first network device and the second network device, the UE can stop communication with the first cell and establish communication with the second cell according to the prior art, that is, according to the first A random access response message sends a handover complete message to the second network device.

With reference to the first aspect, in some implementations of the first aspect, the second timing advance is not zero, and the method further includes: the UE sends first information to the first network device, and The first information is used to instruct the UE to ignore the uplink scheduling authorization information in the first random access response message; the UE receives second information from the first network device, and the second information is used to indicate the first Three timing advances, where the third timing advance is a first common timing advance of the first cell and the second cell.

According to the embodiment of the present application, the first network device can coordinate the public time advance. After the UE receives the first public time advance, the UE can use the first public time advance to send the second random access preamble to the second network device. Code, the UE can receive a second random access response message from the second network device, and the UE can send a handover complete message to the second network device according to the second anytime access response message.

It should be understood that if the first network cannot coordinate the first public TA, the first network equipment station notifies the UE to cancel this handover or notifies the UE to perform a regular handover.

With reference to the first aspect, in some implementation manners of the first aspect, the first information further includes the second timing advance.

According to this embodiment of the present application, when the UE sends the first information to the first network device, the first information may include the second timing advance, which is used to notify the first network device of the parameters of the communication between it and the second network device, avoiding the first Multiple communications between a network device and a second network device.

With reference to the first aspect, in some implementations of the first aspect, the TA is not zero, and the method further includes: the UE receives third information from the first network device, and the third information uses To indicate the adjustment range of the first timing advance; the UE receives fourth information from the second network device, and the fourth information is used to indicate the adjustment range of the second timing advance; the UE Determine a second common timing advance according to the third information and the fourth information, and send a handover complete message to the second network device according to the second common timing advance.

According to the embodiment of the present application, the UE can coordinate the common timing advance, the UE may receive the first timing advance and the adjustment range of the first timing advance from the first network device, and receive the second timing advance and the first timing advance from the second network device. 2. The adjustment range of the timing advance, the UE can determine the second common timing advance according to the range of the first timing advance and the second timing advance, and the UE sends a handover complete message to the second network device according to the second common timing advance , The UE can maintain communication with the first network device and the second network device at the same time, and perform a data connection, so as to achieve a shorter data transmission interruption time when the UE performs cell handover.

It should be understood that if the UE cannot coordinate the second public TA, there are two processing methods. One is that the UE disconnects from the first cell and the UE uses the second TA to send a handover complete message to the target cell; the other is the UE Cancel the random access process and continue to communicate with the first cell, that is, abandon cell handover and perform traditional handover.

With reference to the first aspect, in some implementations of the first aspect, the second timing advance is not zero, and the method further includes: the UE sends the notification to the second network according to the second timing advance The device sends a handover complete message, and the sum of the second timing advance and the first timing advance is the third common timing advance of the first cell and the second cell.

According to this embodiment of the application, the second network device can coordinate the public time advance, and the first network device can carry the first time advance and the adjustment range of the first time advance in the handover request information, and the UE sends the second network device to the second network device. After sending the first random access preamble, the second network device can coordinate the third common time advance and send it to the UE through the first random access response message, where the first random access response message can also indicate The timing advance is a public timing advance, and the UE may establish a connection with the first network device and the second network device according to the third public timing advance.

It should be understood that if the second network device cannot coordinate the third public TA, that is, the UE cannot use the public TA to establish a connection with the first network device and the second network device at the same time, the second network device may instruct the UE to disconnect from the first network device. Open the connection for traditional handover, or the second network device can determine that the public TA cannot be negotiated based on the sixth information sent by the first network device, then the second network device can indicate in the handover confirmation request that the second network device does not support restricted eMBB switching.

With reference to the first aspect, in some implementations of the first aspect, the method further includes: if the UE does not receive the first random access preamble within a first time after the UE sends the first random access preamble Access response message, the UE increases the uplink transmission power, and sends the first random access preamble again, and the increased uplink transmission power is within the first range.

It should be understood that if the uplink transmission power for the second cell is increased, since the UE needs to send information to the first network device and the second network device at the same uplink transmission time, the uplink transmission power of the second cell also needs to be increased at the same time. Consider the impact on the first cell.

With reference to the first aspect, in some implementation manners of the first aspect, the UE receives fifth information, and the fifth information is used to indicate the first range.

According to the embodiment of the present application, the first network device may configure the UE to specify its maximum uplink transmit power.

With reference to the first aspect, in some implementations of the first aspect, after the UE maintains communication with the first network device and the second network device at the same time, the method further includes: the UE continues to measure The second TD and the second PD, when the second TD is greater than the length of the CP or the second PD is greater than the first threshold, the UE ends the communication with the first network device or the second network device, so The second TD is a TD between the first cell and the second cell, and the second PD is a PD between the first cell and the second cell.

With reference to the first aspect, in some implementations of the first aspect, the method further includes: when the second TD is greater than the length of the CP or the second PD is greater than a first threshold, the UE sends first indication information, The first indication information is used to indicate that the second TD or the second PD does not meet a preset condition.

According to the embodiment of the present application, when the UE completes the restricted eMBB handover, the UE maintains communication with the first network device and the second network device at the same time, and can terminate the connection with the other network device in the following manner. The second network device may send an indication message to the UE and the first network device respectively, instructing to stop data transmission between the UE and the first cell. The UE can continuously measure the second TD between the first cell and the second cell and the second PD between the first cell and the second cell. When the second TD or the second PD no longer meets the requirements, it can report to the first network Device or a second network device, and actively terminate the connection with another network device. The UE may send first indication information, the first indication information is used to indicate that the second TD or the second PD does not meet the preset condition, the first indication information may be an RRC message, for example, to notify the network device by sending a measurement report, or It is another message form.

In a second aspect, a method for cell handover is provided, the method includes: a first network device receives first information, where the first information is used to instruct the UE to ignore the uplink scheduling in the first random access response message Authorization information, the first network device is the network device of the first cell currently accessed by the UE; the first network device and the second network device coordinate to determine a third timing advance, and the second network The device is a network device of a second cell, and the second cell is a target cell of the UE; the first network device sends second information to the UE, and the second information is used to indicate a third timing advance , The third timing advance is the first common timing advance of the first cell and the second cell.

With reference to the second aspect, in some implementation manners of the second aspect, the first information further includes a second timing advance, and the second timing advance is used to determine an uplink transmission time at which the UE sends information.

With reference to the second aspect, in some implementation manners of the second aspect, the first information is sent by the UE or the second network device.

With reference to the second aspect, in some implementation manners of the second aspect, the first information is sent by the second network device, and the first information further includes an adjustment range of the second timing advance.

With reference to the second aspect, in some implementation manners of the second aspect, the method further includes: the first network device determines the third timing advance according to the adjustment range.

With reference to the second aspect, in some implementations of the second aspect, the method further includes: the first network device sends coordination request information to the second network device, where the coordination request information is used to indicate the The second network device sends the adjustment range of the second timing advance; the first network device receives the coordination confirmation information sent by the second network device, and the coordination confirmation information is used to indicate the adjustment of the second timing advance range.

In a third aspect, a method for cell handover is provided. The method includes: a second network device receives sixth information from a first network device, where the sixth information is used to indicate a first timing advance and the first The adjustment range of the timing advance, the first timing advance is a communication parameter between the UE and a first network device, and the first network device is the network device of the first cell currently accessed by the UE, and The second network device is the network device of the second cell, and the second cell is the target cell of the UE; the second network device receives the first random access preamble from the UE; the second network device The third common time advance is determined according to the sixth information; the second network device sends a first random access response message to the UE, where the first random access response message is used to indicate the third common time advance .

With reference to the third aspect, in some implementation manners of the third aspect, the sixth information is handover request information.

In a fourth aspect, a method for cell handover is provided. The method includes: a second network device receives a first random access preamble from a UE, and the second network device is the cell of the second cell to which the UE is handed over. Network equipment; the second network equipment sends first information to the first network equipment, the first information is used to instruct the UE to ignore the uplink scheduling authorization information in the first random access response message, the first A network device is the network device of the first cell currently accessed by the UE.

With reference to the fourth aspect, in some implementation manners of the fourth aspect, the first information further includes a second timing advance, and the second timing advance is used to determine an uplink transmission time at which the UE sends information.

With reference to the fourth aspect, in some implementation manners of the fourth aspect, the first information further includes an adjustment range of the second timing advance.

With reference to the fourth aspect, in some implementations of the fourth aspect, the method further includes: the second network device receives coordination request information from the first network device, and the coordination request information is used to indicate the second The network device sends an adjustment range of the second timing advance; coordination confirmation information sent by the second network device to the first network device, where the coordination confirmation information is used to indicate the adjustment range of the second timing advance.

In a fifth aspect, a user equipment is provided, and the user equipment can execute any one of the methods in the first aspect.

In a sixth aspect, a network device is provided, and the user equipment can execute any method in the second aspect.

In a seventh aspect, a network device is provided, and the user equipment can execute any one of the methods in the third aspect.

In an eighth aspect, a network device is provided, and the user equipment can execute any method in the fourth aspect.

In a ninth aspect, a network system is provided. The network system includes at least one user equipment according to the fifth aspect, at least one network device according to the sixth aspect, and at least one network device according to the seventh aspect.

In a tenth aspect, a network system is provided, the network system including at least one user equipment according to the fifth aspect, at least one network device according to the sixth aspect, and at least one network device according to the eighth aspect.

In an eleventh aspect, a computer-readable storage medium is provided. The computer-readable storage medium stores instructions that, when run on a computer, cause the computer to execute the methods described in the above aspects.

Description of the drawings

FIG. 1 is a schematic diagram of the architecture of a mobile communication system applicable to an embodiment of the present application.

Figure 2 is a schematic diagram of a traditional cell handover process.

Fig. 3 is a schematic diagram of a flow of a UE with a dual radio frequency chain or a dual baseband processing unit performing eMBB handover.

FIG. 4 is a schematic flowchart of a method for cell handover provided by an embodiment of the present application.

Figure 5 is a schematic interaction diagram of a method for cell handover provided by an embodiment of the present application

FIG. 6 is a schematic diagram of a UE receiving data sent by two cells at the same time point according to an embodiment of the present application.

FIG. 7 is a schematic diagram of a UE receiving data sent by two cells at the same time point according to an embodiment of the present application.

FIG. 8 is a schematic diagram of the judgment process of the first processing layer provided by an embodiment of the present application.

FIG. 9 is a schematic interaction diagram of a public TA coordinated by a first network device according to an embodiment of the present application.

FIG. 10 is a schematic interaction diagram for UE to coordinate a public TA provided by an embodiment of the present application.

FIG. 11 is a schematic interaction diagram of a second network device for coordinating a public TA according to an embodiment of the present application.

FIG. 12 is a schematic structural diagram of a user equipment according to an embodiment of the present application.

FIG. 13 is a schematic structural diagram of a network device according to an embodiment of the present application.

FIG. 14 is a schematic structural diagram of another network device according to an embodiment of the present application.

FIG. 15 is a schematic structural diagram of another network device according to an embodiment of the present application.

FIG. 16 is a schematic diagram of user equipment provided by an embodiment of the present application.

Figure 17 is a schematic diagram of a network device provided by an embodiment of the present application.

detailed description

The technical solution in this application will be described below in conjunction with the drawings.

FIG. 1 is a schematic diagram of the architecture of a mobile communication system applicable to an embodiment of the present application.

As shown in FIG. 1, the mobile communication system 100 may include multiple network devices 101 and at least one UE 102. Figure 1 is only a schematic diagram. The communication system may also include other network equipment, such as wireless relay equipment and wireless backhaul equipment, which are not shown in Figure 1. The embodiments of the present application do not limit the number and specific types of network devices and UEs included in the mobile communication system.

The UE 102 in the embodiments of the present application may refer to an access terminal, a subscriber unit, a user station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, or a user device. The terminal device can also be a cellular phone, a cordless phone, a Session Initiation Protocol (Session Initiation Orotocol, SIP) phone, a wireless local loop (Wireless Local Loop, WLL) station, a personal digital assistant (Personal Digital Assistant, PDA), with wireless communication Functional handheld devices, computing devices or other processing devices connected to wireless modems, in-vehicle devices, wearable devices, terminal devices in 5G networks or terminals in the future evolution of the Public Land Mobile Network (PLMN) The device, at the same time, may also be various chips used in electronic devices, which is not limited in the embodiment of the present application.

The network device 101 in the embodiment of the present application may be a device used to communicate with terminal devices, and the network device may be a Global System of Mobile Communication (GSM) system or Code Division Multiple Access (CDMA) The network equipment (Base Transceiver Station, BTS) in) can also be the network equipment (NodeB, NB) in the Wideband Code Division Multiple Access (WCDMA) system, or the evolution type in the LTE system The network equipment (Evolutional NodeB, eNB or eNodeB) can also be a wireless controller in the cloud radio access network (Cloud Radio Access Network, CRAN) scenario, or the network equipment can be a relay station, an access point, a vehicle Wearable devices and network equipment in the future 5G network (New Generation NodeB, gNB or gNodeB) or network equipment in the future evolved PLMN network, and subsequent support of the 3rd Generation Partnership Project (3rd Generation Partnership Project, 3GPP) protocol version Network equipment, etc., are not limited in the embodiment of the present application.

Optionally, the communication method of the present application can also be extended to various communication systems, such as GSM system, CDMA system, WCDMA system, General Packet Radio Service (GPRS), LTE system, LTE frequency division duplex ( Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD), Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, The future 5G system or New Radio (NR), etc.

Figure 2 is a schematic diagram of a traditional cell handover process.

As shown in Figure 2, in the traditional handover scheme, in the cellular communication system, when the UE moves, the handover of the serving cell can occur according to the change of signal strength or the demand of load balancing on the network equipment side. In the traditional handover method, when the UE receives a handover command, the UE will disconnect the RRC connection with the serving cell, and then start a random access process for the target cell. After sending a handover complete message to the target cell, the UE resumes RRC connection. During the handover process from the UE disconnecting from the serving cell to establishing a connection with the target cell, the data transmission of the UE is interrupted, and the UE cannot perform data transmission with the network equipment.

Fig. 3 is a schematic diagram of a flow of a UE with a dual radio frequency chain or a dual baseband processing unit performing eMBB handover.

As shown in Figure 3, in order to reduce the interruption time of data transmission during the UE handover, the make-before-break technology is proposed. The main improvement is that when the UE receives the handover command, it does not immediately interrupt the connection. The connection of the serving cell is maintained until the UE's first uplink transmission time for the target cell. For example, after the UE receives the handover command, the communication with the serving cell is still maintained, and it is not interrupted until the UE sends a random access preamble to the target cell. In this way, during the random access process between the UE and the target cell, the data transmission is interrupted, which reduces the time of data interruption.

Optionally, the eMBB scheme, or called the simultaneous connection handover scheme, is a scheme in which the UE connects to the serving cell and the target cell at the same time. Compared with the MBB scheme, even in the random access process between the UE and the target cell, the UE and the serving cell The connection of the cell serving cell is not interrupted. In this way, when the UE is handed over from the serving cell to the target cell, there will be a period of time when the UE maintains a connection with the serving cell and the target cell at the same time, and can also perform data transmission at the same time. The serving cell is the cell that establishes a connection with the current UE. In this way, the effect of 0ms handover interruption can be achieved, and the data transmission between the UE and the network device is not affected.

For a scenario where two network devices are connected at the same time, although this switching method reduces the interruption time of data transmission during the switching process, it requires the UE to have two sets of radio frequency chains and two sets of FFT processors. This greatly increases the cost and is not conducive to the promotion of the technology.

This application provides a method for achieving zero data interruption time cell handover for UEs with only a single radio frequency chain or a single FFT processor, which can reduce costs while ensuring a short or zero data transmission interruption time, which is beneficial The promotion of this technology.

It should be understood that the technical solution of the present application can also be applied to a UE that includes multiple radio frequency chains and multiple FFT processors. The UE only uses a single radio frequency chain or a single FFT processor to perform a short data interruption time. Within the scope of protection applied for.

The eMBB handover scheme, also known as the Non-Split Bearer handover scheme, 0ms handover scheme, etc., mainly uses the UE to maintain data transmission with the serving cell and the target cell at the same time to achieve uninterrupted data transmission during the handover process. A UE with two sets of FFT and two sets of radio frequency chains can support simultaneous uplink and downlink transmissions for two cells without considering additional constraints. For a UE with only a single set of FFT, it can actually only work according to one time point, that is, perform FFT operation on downlink data according to downlink time point, and perform inverse Fast Fourier transform of uplink data according to uplink time point. Transform, IFFT) operation.

FIG. 4 is a schematic flowchart of a method for cell handover according to an embodiment of the present application. The method in FIG. 4 may be executed by the UE 102 in FIG. 1.

S401. The UE determines a first uplink sending moment according to a first time advance (Time Advance, TA), where the first TA is a communication parameter between the UE and the first network device, and the first uplink sending moment is the UE to the first network device. At the moment of sending the information, the first network device is the network device of the first cell that the UE currently accesses.

Among them, the first uplink sending moment can be determined according to the UE’s first downlink receiving moment and the first TA, where the first downlink receiving moment is the time when the UE receives the downlink signal of the first cell, and the first uplink moment is the UE sending the uplink The time of the signal.

Optionally, the UE may send capability information to the first network device, and the capability information is used to indicate that the UE is a UE with a single FFT processor or a single radio frequency link, or the UE has the capability of simultaneous connection switching, or the UE has Downlink timing deviation (Time Difference, TD) and downlink power deviation (Power Difference, PD) measurement capabilities.

Optionally, the UE may also receive first measurement indication information from the first network device, the first measurement indication information is used to instruct the UE to measure the first TD and the first PD, and the first TD may be between the first cell and the second cell. The first PD is the PD between the first cell and the second cell.

Optionally, the first measurement indication information may also be used to indicate information such as frequency information measured by the UE, and the UE may perform TD measurement on all cells on the frequency that can receive signals.

Optionally, the first measurement indication information may include a first cell list, the first cell list may be used to indicate a cell to be measured, the cell to be measured includes a second cell, and the second cell is a cell currently measured by the UE.

Optionally, the first measurement indication information may also configure a separate reference signal resource for downlink timing measurement for the UE. For example, the UE can measure the reference signal of the second cell. The reference signal can be the Primary Synchronization Signal (PSS), the Secondary Synchronization Signal (SSS), and the Cell Reference Signal (Cell Reference Signal) in LTE. , CRS), channel state information reference signals (CSI reference signals, CSI-RS), and synchronization signal block (Synchronization Signal Block, SSB) in NR, CSI-RS, etc.

Optionally, the first measurement indication information may also be used to indicate the timing for the UE to report the measurement results of the first TD and the first PD to the first network device. There may be two types of timing for reporting the measurement results. One type is event triggering. , The other is periodic reporting.

Optionally, the first measurement indication information may be a broadcast message or measurement configuration information.

Optionally, the UE may also send first measurement result information to the first network device, the first measurement result information is used to indicate the measurement result of the first TD, and the first measurement result information is also used to indicate the measurement result of the first PD .

Optionally, the first measurement result information includes the values of the first TD and the first PD, or the first measurement result information includes whether the first TD is smaller than the length of a cyclic prefix (Cyclic Prefix, CP) and whether the first PD is smaller than the first PD. The indication of the threshold, or the first measurement result information includes index values of different gears corresponding to the first TD and the first PD.

Optionally, the first threshold may be configured by the first network device for the UE, and the first threshold may be included in the first measurement indication information, or the first threshold may also be specified by the protocol.

Optionally, the first measurement result information may be measurement report information.

Optionally, the first measurement result information may be triggered by a measurement event or sent periodically.

Optionally, the UE receives handover instruction information sent by the first network device, where the handover instruction information is used to instruct the UE to perform cell handover to the second cell, where the first TD is less than or equal to the length of the cyclic prefix CP, and the first PD is less than The first threshold.

S402: The UE sends a first random access preamble to a second network device at the first uplink sending moment, the second network device is a network device of a second cell, and the second cell is a target cell of the UE.

Optionally, the second network device may determine the second TA according to the first random access preamble.

Optionally, the UE may also send first data information to the first network device while sending the first random access preamble, where the first data information may be sent through an uplink data channel.

S403. The UE receives a first random access response message in response to the first random access preamble from the second network device.

Optionally, the first random access response message includes a second TA, and the second TA is used to determine the uplink sending time of the UE sending information.

It should be understood that the second TA may be an increment of the first TA, and the information sent by the UE to the first network device and the second network device may be sent at the same uplink sending time, that is, after the second TA is applied, the UE sends according to the first uplink The time and the second TA may determine the second uplink transmission time, and the UE may also determine the second uplink transmission time according to the first downlink reception time, the first TA, and the second TA.

Optionally, the second TA may be zero, that is, the UE may apply the first TA to establish communication with the second network device, and the UE may send a handover complete message to the second network device according to the first TA.

Optionally, the second TA may not be zero, that is, the UE cannot use the first TA to establish communication with the second network device, and the UE or the first network device or the second network device needs to coordinate the common TA.

It should be understood that when the coordination is unsuccessful, that is, there is no common TA between the first network device and the second network device, the UE can stop communication with the first cell and establish communication with the second cell according to the prior art, that is, according to the first A random access response message sends a handover complete message to the second network device.

Optionally, before sending the handover complete message, the UE may also send notification information for ending communication to the first network device.

The first network device coordinates the public TA:

The UE sends first information to the first network device, the first information is used to indicate the second TA, the UE receives the second information from the first network device, and the second information is used to indicate the third TA, and the third TA is the first cell and The first public TA of the second cell.

Optionally, the first information may include an indication that the UE ignores the uplink scheduling grant information (UL-Grant) in the first random access response message.

Optionally, the UE may use the first public TA to send the second random access preamble to the second network device, the UE may receive the second random access response message from the second network device, and the UE may access the response at any time according to the second The message sends a handover complete message to the second network device.

UE coordinates public TA:

The UE may receive third information from the first network device, where the third information is used to indicate the adjustment range of the first TA. The UE receives fourth information from the second network device, or receives a fourth message from handover instruction information sent by the first network device, where the fourth information is used to indicate the adjustment range of the second TA. After receiving the first random access response message, the UE determines the second public TA according to the second TA and the corresponding adjustment ranges of the first and second TAs, and sends a handover complete message to the second network device according to the second public TA .

The second network device coordinates the public TA:

The UE receives the first random access response message, which includes the second TA. The second TA is the increment of the first TA coordinated by the second network device, that is, from the UE’s first downlink receiving moment, the first TA and The sum of the second TA may be the third common TA of the first network device and the second network device. In this way, the first network device needs to notify the second network device of the adjustment range of the first TA in advance.

S404: The UE maintains communication with the first network device and the second network device at the same time, and the UE can send data to the first network device and the second network device at the same time.

FIG. 5 is a schematic interaction diagram of a method for cell handover provided by an embodiment of the present application. The method in FIG. 5 may be executed by the network device 101 and the UE 102 in FIG. 1.

S501: The UE may send capability information to the first network device.

Optionally, the capability information may be used to indicate that the UE is a UE with a single FFT processor or a single radio frequency link, or the UE has the capability of simultaneous connection handover, or the UE has the capability of TD and PD measurement.

S502: The first network device may send first measurement indication information to the UE, where the first measurement indication information is used to instruct the UE to measure the first TD and the first PD.

Optionally, the first measurement indication information may also be used to indicate information such as frequency information measured by the UE, and the UE may perform TD and PD measurements on all cells that can receive signals under this frequency.

Optionally, the first measurement indication information may include a first cell list, the first cell list may be used to indicate a cell to be measured, and the cell to be measured includes a second cell.

Optionally, the first measurement indication information may also configure a separate reference signal resource for downlink timing measurement for the UE. For example, the UE may measure the reference signal of the second cell. The reference signal may be the primary PSS, SSS, CRS, CSI-RS in LTE, and SSB and CSI-RS in NR.

Optionally, the first measurement indication information may also be used to instruct the UE to report the trigger mode of the measurement results of the first TD and the first PD to the first network device, which can be divided into two types, one is event triggering, and the other is It is reported periodically.

Optionally, the first measurement indication information may be a broadcast message or dedicated measurement configuration information.

S503: The UE may measure the first TD and the first PD between the first cell and the second cell.

Figures 6 and 7 are schematic diagrams of the UE receiving data sent by two cells at the same time point.

When the UE only performs data communication with one cell, the FFT operation is performed on the downlink data, and the FFT operation is performed on each symbol according to the downlink synchronization time point of the current serving cell.

As shown in Figure 6, each symbol is composed of CP121 and data content 122. The definition of the downlink timing deviation (TD) 130 can be (downlink synchronization time point of the measurement cell-downlink synchronization time point of the serving cell) or (downlink synchronization time point of the serving cell-downlink synchronization time point of the measurement cell), This patent does not limit it, where the serving cell is the cell currently accessed by the UE, and the downlink synchronization time point is used to indicate the starting position of the subframe.

Take (TD = the downlink synchronization time point of the measuring cell-the downlink synchronization time point of the serving cell) as an example, if the downlink synchronization time point of the measurement cell lags the downlink synchronization time point of the serving cell, the TD value is positive; if the measurement cell The downlink synchronization time point of is ahead of the downlink synchronization time point of the serving cell, and TD is a negative value. Optionally, the obtained preliminary TD result can also be used or reported after taking the absolute value.

It should be understood that when the UE performs the FFT operation on the downlink data, the FFT window 110 is used to obtain the data content of the data symbols sent by the serving cell. If TD≤CP, the UE can also obtain the data content sent by the measuring cell when obtaining the data content sent by the serving cell. Part of the CP and part of the data content in the data symbols. Due to the characteristics of the CP, the acquired part of the CP can complete the missing part of the data content. The UE can perform an FFT operation at the same time point to obtain the serving cell and the measurement cell at the same time The content of the data sent. If TD>CP, the data of the two cells cannot be fully obtained in one FFT window, and the data of other symbols will be mixed in one FFT window. At this time, after the FFT operation, large inter-symbol interference will occur, thus Affect the correctness of data reception, as shown in Figure 7.

For a UE with a single radio frequency chain or a single FFT processor, if the data of two cells needs to be received at the same time, the length of the two cells is less than or equal to the CP, that is, TD≤CP.

At the same time, for a UE with a single radio frequency chain or a single FFT processor to perform eMBB handover, the UE also needs to measure the downlink power difference (PD) between the serving cell and the measured cell. When the PD meets the requirements, the UE It can receive messages and establish a connection with the serving cell and the measuring cell at the same time.

Optionally, for measurements such as Reference Signal Received Power (RSRP), the physical layer needs to periodically report the measurement result to the first processing layer, and the L3 filtering result of the first processing layer is used to determine whether the measurement report is satisfied condition. Similar to the RSRP measurement mechanism, the physical layer of the UE can also directly calculate the TD result after measuring the downlink synchronization time point of the two cells. Then the TD raw data is reported to the first processing layer, and the first processing layer performs L3 filtering to obtain specific results.

Among them, the first processing layer is a layer higher than the physical layer, and the first processing layer can process the original data. For example, the first processing layer can be the RRC layer, upper layer, application layer, presentation layer, session layer, transport layer, Network layer or data link layer.

The L3 filter has been standardized, and the specific filtering formula is as follows:

F _n ＝(1-a)·F _n-1 +a·M _n

Mn is the measurement result of the latest output of the L1 filter;

Fn is the output result of the updated L3 filter and is also used as the input of the evaluation module;

Fn-1 is the historical L3 filter output, and F0 is set to M1. It can be obtained from the formula that F1 is equal to M1, that is, the first result output by the L1 filter is the output of the L3 filter.

a=1/2(k/4), k is the L3 filter coefficient, and different measurement quantities can have different k values.

Optionally, the physical layer of the UE may directly indicate to the first processing layer whether the first TD is smaller than the length of the CP after measuring the first TD.

The physical layer does not need to report the specific first TD value, but only needs to report to the higher layer whether the first TD is smaller than the CP. One possible way is:

TD1≤CP, the result of the physical layer reporting to the first processing layer is yes;

TD1>CP, the result of the physical layer reporting to the first processing layer is no;

Among them, TD1 is the first TD.

Optionally, the indication may be reported periodically.

Optionally, when the report of the physical layer to the first processing layer is performed periodically, the first processing layer may determine whether the first TD is less than the length of the CP according to the number of continuously obtained Yes. For example, the first network device may configure two thresholds for the UE, namely the seventh threshold K1 and the eighth threshold K2. When the number of consecutively reported Yes from the physical layer is greater than or equal to K1, the first processing layer considers that the first TD is less than Or equal to the length of the CP; when the number of negative results reported by the physical layer to the first processing layer is greater than or equal to K2, the first processing layer considers that the first TD is greater than the length of the CP.

As shown in Figure 8, when K1=6 and K2=4, the judgment process of the first processing layer.

Optionally, the seventh threshold K1 and the eighth threshold K2 can also be directly specified in the agreement

Similar to the TD measurement mechanism, the physical layer of the UE can also directly calculate the PD result after measuring the PD at the downlink timing point of the two cells. Then the original data of the PD is reported to the first processing layer, and the first processing layer performs L3 filtering to obtain specific results.

Optionally, the UE may directly send the RSRP values of the two cells to the first network device after measuring the RSRP of the first cell and the second cell, and the first network device calculates the first PD.

Optionally, the physical layer of the UE reports to the first processing layer once after measuring the original data of the first PD, and the first processing layer performs L3 filtering to obtain specific results. The unit of the first PD can be Decibel Relative to One Milliwatt (dBm), or other units that indicate signal strength.

Optionally, the physical layer of the UE may directly report to the first processing layer whether the first PD is less than the first threshold. For example, the first network device may configure two thresholds for the UE, namely the ninth threshold K3 and the tenth threshold K4. , When the number of continuous reports by the physical layer is greater than or equal to K3, the first processing layer considers that the first PD is less than or equal to the first threshold; when the number of results reported by the physical layer to the first processing layer is greater than or equal to K4 When, the first processing layer considers that the first PD is greater than the first threshold. This indication can be reported periodically.

Optionally, the UE may calculate the first PD based on the RSRP measurement results of the first cell and the second cell that have been currently measured. The UE will perform RSRP measurement for the cell to be measured or the cell currently connected, and the measurement result is also filtered by L3, so the existing RSRP result can be directly used for the first PD calculation.

It should be understood that when the physical layer of the UE directly calculates the first PD, the power deviation requirement will be more strictly observed. However, for the UE to directly use the existing RSRP result to calculate the first PD, since the RSRP result has been filtered by L3 and the result has been smoothed, the power deviation requirement reflected by the direct use of the RSRP result will be weaker.

S504: The UE may send first measurement result information to the first network device, where the first measurement result information is used to indicate the measurement result of the first TD, and the first measurement result information is also used to indicate the measurement result of the first PD.

Optionally, the first measurement result information includes the values of the first TD and the first PD, or the first measurement result information includes an indication whether the first TD is less than the length of the CP and the first PD is less than the first threshold, or the first The measurement result information includes index values of different gear positions corresponding to the first TD and the first PD.

Optionally, the first threshold may be configured by the first network device for the UE, and the first threshold may be included in the first measurement indication information, or the first threshold may also be specified by the protocol.

Optionally, the first measurement result information may be measurement report information.

Optionally, the first measurement result information may be triggered by other measurement events or sent periodically.

Optionally, in the event of triggering, the UE does not trigger a separate report after measuring the first TD. The first network device may add an indication of reporting the first TD result in different reporting configurations. For example, configure an A3 event reporting configuration, and when the signal strength of the second cell reaches the reporting standard of the A3 event, the UE will report the corresponding measurement results related to the second cell. At this time, the first TD measurement result will also be attached to the measurement report. The form of the first TD result may be a specific first TD value, an indication of whether the first TD is less than the length of the CP, or the index values of different gears corresponding to the first TD value.

Optionally, a TD-specific measurement event can also be defined. For example, the entry condition of the event is the length of TD≤CP. When the event entry condition is met, the measurement report is triggered, and the UE sends the measurement result of the first TD to the first network device.

Among them, for the first TD report, a new measurement event can be defined. When the first TD measurement result meets the entry condition of the event and meets the time-to-trigger requirement, the measurement report is triggered. When the first TD measurement result meets the leaving condition of the event, the report can also be triggered.

For example, to define a measurement event M1, the event M1 can be that the measurement result of the first TD is less than the length of the CP, and the corresponding entry conditions for M1 are:

TD1+H1<CPlength,

The leaving conditions are:

TD1–H1>CPlength,

Among them, H1 is the first hysteresis value;

Among them, TD1 is the first TD.

Optionally, the first network device may send second measurement indication information, and the second measurement indication information may indicate the specific value of the first hysteresis value of the UE.

Optionally, the second measurement indication information may be the first measurement indication information.

Optionally, another TD-specific measurement event can also be defined. The entry condition of the event is that the number of indications reported by the physical layer to the first processing layer exceeds the preset threshold.

For example, to define measurement event N1, event N1 can be that the measurement result of TD is less than the length of CP, and the corresponding entry conditions for N1 are:

The number of continuous reports at the physical layer ≥ the third threshold K5,

The leaving conditions are:

The number of consecutive no-reports at the physical layer ≥ the fourth threshold K6.

Optionally, measurement event N2 can be defined. Event N2 can be that the measurement result of TD is greater than the length of CP. The corresponding entry conditions for N2 are:

The number of consecutively reported negatives at the physical layer ≥ the third threshold K5,

The leaving conditions are:

The number of continuous reports of the physical layer is ≥ the fourth threshold K6.

Optionally, in the event of triggering, the UE does not trigger a separate report after measuring the first PD. The first network device may add an indication of reporting the first PD result in different reporting configurations. For example, configure a report configuration for the A3 event, and when the signal strength of the second cell reaches the reporting standard of the A3 event, the UE will report the corresponding measurement results related to the second cell. At this time, the first PD measurement result will also be attached to the measurement report. The form of the first PD result may be a specific first PD value, an indication of whether the first PD is smaller than the length of the CP, or the index values of different gears corresponding to the first PD value, etc.

Optionally, a PD-specific measurement event can also be defined. For example, the entry condition of the event is PD≦the first threshold. When the event entry condition is met, the measurement report is triggered, and the UE sends the measurement result of the first PD to the first network device.

Among them, for the first PD report, a new measurement event can be defined. When the first PD measurement result meets the entry condition of the event and meets the trigger time requirement, the measurement report is triggered. When the first PD measurement result meets the leaving condition of the event, the report may also be triggered.

For example, to define a measurement event M2, the event M2 can be that the measurement result of the first PD is less than the first threshold, and the corresponding entry condition of M1 is:

PD1+H2<the first threshold,

The leaving conditions are:

PD1–H2>the first threshold,

Among them, H2 is the second hysteresis value;

Among them, PD1 is the first PD.

Optionally, the first network device may send third measurement indication information, and the third measurement indication information may indicate the specific value of the second hysteresis value of the UE.

Optionally, the third measurement indication information may be the first measurement indication information.

Optionally, another PD-specific measurement event can also be defined. The entry condition of the event is that the number of indications reported by the physical layer to the first processing layer exceeds the preset threshold.

For example, to define measurement event N3, event N3 can be that the measurement result of PD is less than the first threshold, and the corresponding entry condition for N3 is:

The number of continuous reports at the physical layer ≥ the fifth threshold K7,

The leaving conditions are:

The number of consecutive no-reports at the physical layer ≥ the sixth threshold K8.

Optionally, a measurement event N4 can be defined. Event N4 can be that the measurement result of the PD is greater than the first threshold. The corresponding entry condition for N4 is:

The number of consecutive no-reports at the physical layer ≥ the fifth threshold K7,

The leaving conditions are:

The number of consecutively reported yes from the physical layer ≥ the sixth threshold K8.

S505: The first network device receives the first measurement result information from the UE, obtains the measurement result of the first TD and the measurement result of the first PD, and the first network device determines the first TD according to the measurement result of the first TD and the measurement result of the first PD. Whether the measurement result of a TD is less than the length of the CP, and determine whether the measurement result of the first PD is less than the first threshold, and if the results are all yes, the first network device sends handover instruction information to the UE.

S506: The first network device may send handover request information to the second network device.

Wherein, the first network device judges that the UE meets the condition of restricted eMBB handover, and sends handover request information to the second network device, which carries the restricted eMBB handover instruction. Restricted eMBB handover is a UE with a single radio frequency chain or a single FFT processor performing eMBB handover.

S507: The second network device makes a judgment according to the handover request information.

Among them, if the second network device can accept the restricted eMBB handover, the second network device will return the handover confirmation message and indicate that it agrees to use the restricted eMBB handover; if the second network device can accept the handover but does not accept the restricted eMBB handover, The second network device returns the handover confirmation message, but instructs not to use the restricted eMBB handover; if the second network device does not accept the handover, it indicates the handover rejection to the first network device.

S508: The second network device returns handover confirmation information to the first network device, where the handover confirmation information may carry a container for the handover instruction information.

Optionally, the handover instruction information may be an RRC reconfiguration message.

S509: The first network device sends the handover instruction information in the handover confirmation information to the UE, where the handover instruction information is used to instruct the UE to perform cell handover to the second cell.

Among them, if the second network device accepts restricted eMBB handover, the handover instruction information will instruct the UE to perform restricted eMBB handover; if the second network device does not accept restricted eMBB handover, the handover instruction information adopts the existing message format, such as RRC reconfiguration. Configuration message.

When the UE receives the handover instruction information indicating the restricted eMBB mode, on the one hand, the UE will continue to maintain communication with the first network device, and on the other hand, it will start to send the random access preamble to the second network device, that is, start random Access process.

S510: The UE determines the first uplink sending time according to the first TA, the first TA is a communication parameter between the UE and the first network device, and the first uplink sending time is the time when the UE sends information to the first network device. The UE sends the first random access preamble to the second network device at the first uplink sending moment.

Among them, the first uplink sending moment can be determined according to the UE’s first downlink receiving moment and the first TA, where the first downlink receiving moment is the time when the UE receives the downlink signal of the first cell, and the first uplink moment is the UE sending the uplink The time of the signal.

Optionally, the second network device may determine the second TA according to the first random access preamble.

S511: The second network device may send a first random access response message to the UE according to the received first random access preamble.

Optionally, the first random access response message includes a second TA, and the second TA is used to determine the uplink sending time of the UE sending information.

Optionally, the first random access response message may include uplink scheduling authorization information.

It should be understood that the second TA may be an increment of the first TA, and the information sent by the UE to the first network device and the second network device may be sent at the same uplink sending time, that is, after the second TA is applied, the UE sends according to the first uplink The time and the second TA may determine the second uplink transmission time, or the UE may also determine the second uplink transmission time according to the first downlink reception time, the first TA and the second TA.

Optionally, the second TA may be zero, that is, the UE may apply the first TA to establish communication with the second network device, and the UE may send a handover complete message to the second network device according to the first TA.

Optionally, the second TA may not be zero, that is, the UE cannot use the first TA to establish communication with the second network device, and the UE or the first network device or the second network device needs to coordinate the common TA.

It should be understood that when the coordination is unsuccessful, that is, there is no common TA between the first network device and the second network device, the UE can stop communication with the first cell and establish communication with the second cell according to the prior art, that is, according to the first A random access response message sends a handover complete message to the second network device, and at the same time, the UE may also send notification information to end communication to the first network device.

Optionally, if the UE sends the first random access preamble to the second cell according to the first uplink transmission time and transmission power of the first cell, if the UE does not receive the first random access preamble within the first time after the first random access preamble is sent When the first random access response message is reached, the UE may increase the uplink transmission power and send the first random access preamble again, and the increased uplink transmission power is within the first range.

It should be understood that if the uplink transmission power for the second cell is increased, since the UE needs to send information to the first network device and the second network device at the same uplink transmission time, the uplink transmission power of the second cell also needs to be increased at the same time. Consider the impact on the first cell.

Optionally, the UE receives fifth information, where the fifth information is used to indicate the first range for adjusting the uplink transmit power.

For example, the first network device may indicate that the first range that the UE can adjust is ±5dBm. When the UE performs power boost, when the boost value is within the range, it can be executed normally. If it is within the increasing range, the first random access response message cannot be received even after reaching the maximum value. The UE may notify the first network device of the failure of random access, or directly perform traditional handover (that is, disconnect the connection with the first network device while continuing to increase the transmission power of the preamble).

Optionally, when the uplink transmission power of the UE for the second cell is increased, correspondingly, the uplink transmission power of the UE for the first cell may remain unchanged, or increase in synchronization.

S512: When the second TA is zero, the UE may send a handover complete message to the second network device, and the UE maintains communication with the first network device and the second network device at the same time.

For the case that the second TA is not zero, the public TA can be coordinated by the first network device, the public TA can be coordinated by the UE, or the public TA can be coordinated by the second network device. After the UE obtains the public TA, it can send to the second network device Preamble or handover complete message.

Fig. 9 is a schematic interaction diagram of the first network device to coordinate a public TA.

S901: The first network device receives first information. The first information may be used to instruct the UE to ignore the uplink scheduling authorization information in the first random access response message, that is, the first information is used to indicate that the UE cannot apply the first TA and The second network device establishes communication.

It should be understood that the first network device can coordinate with the second network device to determine the third TA, and the UE can use the third TA to establish communication with the second network device while maintaining communication with the first network device. The third TA is the first cell. And the first public TA of the second cell.

Optionally, the first information further includes a second TA, and the second TA is used to determine the uplink sending time when the UE sends the handover complete message. When the first information only includes the second TA, the first network device can determine whether it can use the second TA to communicate, if it is, the third TA is the second TA, and if it is, it is determined that the third TA cannot be coordinated.

Optionally, the first information may be sent by the UE or the second network device.

Optionally, when the first information is sent by the second network device, the first information may also include the adjustment range of the second TA. The first network device determines the first common TA according to the adjustment range of the second TA.

When the first information is sent by the UE, the method for the first network device to coordinate the public TA may further include:

S902: The first network device may send coordination request information to the second network device, where the coordination request information is used to instruct the second network device to send an adjustment range of the second TA.

S903: The second network device may send coordination confirmation information to the first network device, where the coordination confirmation information is used to indicate the adjustment range of the second TA.

S904: The first network device may coordinate the first public TA according to the adjustment range of the second TA in the coordination confirmation information.

S905: The first network device sends second information to the UE, where the second information is used to indicate the first public TA, and the UE applies the first public TA while maintaining communication with the first network device and the second network device.

When the first information is sent by the second network device, the method for the first network device to coordinate the public TA may further include:

S904: The first network device may coordinate the first common TA based on the adjustment range of the second TA in the first information.

S905: The first network device sends second information to the UE, where the second information is used to indicate the first public TA, and the UE applies the first public TA while maintaining communication with the first network device and the second network device.

It should be understood that after the UE receives the first public TA, the UE can use the first public TA to send the second random access preamble to the second network device, and the UE can receive the second random access response message from the second network device. The UE may send a handover complete message to the second network device according to the second anytime access response message.

Optionally, if the coordination process of the first public TA can be completed quickly, the second network device may also indicate the first public TA. For example, the first public TA may be indicated in the random access response message, and the first public TA needs to be indicated at the same time. This is a public TA.

Optionally, after the first network device makes the first public TA to the second network device, the second network device allocates a dedicated periodic uplink scheduling authorization information for the UE, and sends it to the first network device, and then the first network device The device forwards it to the UE for the UE to send a handover complete message.

Optionally, the second network device may directly send scheduling information to the UE, indicating the first public TA and uplink scheduling authorization information, and directly schedule the UE to send the handover complete message.

It should be understood that if the first network device cannot coordinate the first public TA, the first network device station notifies the UE to cancel this handover or notifies the UE to perform a regular handover.

Fig. 10 is a schematic interaction diagram of the UE coordinating a common TA.

S1001: The first network device may send and receive third information to the UE, where the third information is used to indicate the adjustment range of the first TA.

S1002: The UE receives fourth information from the second network device, where the fourth information is used to indicate the adjustment range of the second TA.

Optionally, the fourth information may also be obtained from the switching instruction information, that is, after being generated by the second network device, the second network device may send the fourth information to the first network device through the switching confirmation message in S508, Then forward to the UE through the first network device.

S1003: The UE determines the second common TA according to the third information and the fourth information.

When the UE performs random access in the second cell, the UE will receive the second TA of the second cell in the first random access response message. The UE can then compare the TA values and corresponding adjustment ranges in the two cells to determine whether the second common TA can be selected. If the second public TA can be selected, the handover complete message is directly sent to the second cell.

S1004, and send a handover complete message to the second network device according to the second public TA, and the UE maintains communication with the first network device and the second network device at the same time.

It should be understood that if the UE cannot coordinate the second public TA, there are two processing methods. One is that the UE disconnects from the first cell and the UE uses the second TA to send a handover complete message to the target cell; the other is the UE Cancel the random access process and continue to communicate with the first cell, that is, abandon cell handover and perform traditional handover.

Fig. 11 is a schematic interaction diagram of a second network device coordinating a public TA.

S1101: The first network device sends sixth information to the second network device, where the sixth information is used to indicate the first TA and the adjustment range of the first TA.

Optionally, the sixth information may be handover request information, as shown in S506 in FIG. 5.

S1102. The UE sends a first random access preamble to the second network device.

The second network device may determine the second TA according to the first random access preamble.

S1103: The second network device may coordinate the third public TA according to the sixth information.

Optionally, the second network device may send seventh information to the first network device to indicate the third public TA.

Optionally, the seventh information may be handover confirmation information, as shown in S508 in FIG. 5.

S1104: The second network device may send a first random access response message to the UE according to the first random access preamble, where a third common TA may be indicated.

S1105: The UE sends a handover complete message to the second network device according to the third public TA, and the UE maintains communication with the first network device and the second network device at the same time.

It should be understood that if the second network device cannot coordinate the third public TA, that is, the UE cannot use the public TA to establish a connection with the first network device and the second network device at the same time, the second network device may instruct the UE to disconnect from the first network device. Open the connection for traditional handover, or the second network device can determine that the public TA cannot be negotiated based on the sixth information sent by the first network device, then the second network device can indicate in the handover confirmation request that the second network device does not support restricted eMBB switching.

When the UE completes the restricted eMBB handover, the UE maintains communication with the first network device and the second network device at the same time, and can end the connection with another network device in the following manner.

Optionally, the second network device may send an indication message to the UE and the first network device respectively to instruct to stop data transmission between the UE and the first cell.

Optionally, the UE can continuously measure the second TD between the first cell and the second cell and the second PD between the first cell and the second cell. When the second TD or the second PD no longer meets the requirements, it can Report the first network device or the second network device, and actively terminate the connection with another network device.

Optionally, the UE may send first indication information, the first indication information is used to indicate that the second TD or the second PD does not meet a preset condition, and the first indication information may be an RRC message, for example, to notify the network by sending a measurement report The device can also be in other message formats without limitation.

FIG. 12 is a schematic structural diagram of a user equipment according to an embodiment of the present application.

As shown in FIG. 12, the UE may include a receiving module 1201, a processing module 1202, and a sending module 1203.

The processing module 1202 may be configured to determine the first uplink transmission time according to the first TA. The first TA is a communication parameter between the UE and the first network device, and the first uplink transmission time is the time when the UE sends information to the first network device. At the moment, the first network device is the network device of the first cell currently accessed by the UE.

The sending module 1203 may be configured to send the first random access preamble to the second network device at the first uplink sending moment, the second network device is the network device of the second cell, and the second cell is the target cell of the UE.

The receiving module 1201 may be configured to receive a first random access response message in response to the first random access preamble from the second network device.

Optionally, the sending module 1203 is further configured to send the first data information to the first network device when the UE sends the first random access preamble. The processing module 1202 can be used to measure the first TD and the first PD. The first TD is the TD between the first cell and the second cell, the first PD is the PD between the first cell and the second cell, and the first network The device is the network device of the first cell that the UE currently accesses, and the second network device is the network device of the second cell.

The sending module 1203 may be configured to send first measurement result information to the first network device, where the first measurement result information is used to indicate the measurement result of the first TD; and the first measurement result information is also used to indicate the measurement result of the first PD.

The receiving module 1201 may be used to receive handover instruction information sent by the first network device, where the handover instruction information is used to instruct the UE to perform cell handover to the second cell, where the first TD is less than or equal to the length of the CP, and the first PD is less than or Equal to the first threshold.

Optionally, the receiving module 1201 may also be configured to receive first measurement indication information from the first network device, where the first measurement indication information is used to instruct the UE to measure the first TD and the first PD.

Optionally, the first measurement indication information includes a first cell list, the first cell list is used to indicate a cell to be measured, and the cell to be measured includes a second cell.

Optionally, the first measurement result information includes the values of the first TD and the first PD, or the first measurement result information includes an indication whether the first TD is less than the length of the CP and the first PD is less than the first threshold, or the first The measurement result information includes index values of different gear positions corresponding to the first TD and the first PD.

Optionally, the receiving module 1201 sends the first measurement result information to the first network device after being triggered by an event or periodically.

Optionally, in the event of triggering, the UE does not trigger a separate report after measuring the first TD. The first network device may add an indication of reporting the first TD result in different reporting configurations. For example, configure an A3 event reporting configuration, and when the signal strength of the second cell reaches the reporting standard of the A3 event, the UE will report the corresponding measurement results related to the second cell. At this time, the first TD measurement result will also be attached to the measurement report. The form of the first TD result may be a specific first TD value, an indication of whether the first TD is less than the length of the CP, or the index values of different gears corresponding to the first TD value.

Optionally, a TD-specific measurement event can also be defined. For example, the entry condition of the event is the length of TD≤CP. When the event entry condition is met, the measurement report is triggered, and the UE sends the measurement result of the first TD to the first network device.

Among them, for the first TD report, a new measurement event can be defined. When the first TD measurement result meets the entry condition of the event and meets the requirement of the trigger time, the measurement report is triggered. When the first TD measurement result meets the leaving condition of the event, the report can also be triggered.

For example, to define a measurement event M1, the event M1 can be that the measurement result of the first TD is less than the length of the CP, and the corresponding entry conditions for M1 are:

TD1+H1<CPlength,

The leaving conditions are:

TD1–H1>CPlength,

Among them, H1 is the first hysteresis value;

TD1 is the first TD.

Optionally, the first network device may send second measurement indication information, and the second measurement indication information may indicate the specific value of the first hysteresis value of the UE.

Optionally, the second measurement indication information may be the first measurement indication information.

Optionally, another TD-specific measurement event can also be defined. The entry condition of the event is that the number of indications reported by the physical layer to the first processing layer exceeds the preset threshold.

For example, to define measurement event N1, event N1 can be that the measurement result of TD is less than the length of CP, and the corresponding entry conditions for N1 are:

The number of continuous reports at the physical layer ≥ the third threshold K5,

The leaving conditions are:

The number of consecutive no-reports at the physical layer ≥ the fourth threshold K6.

Optionally, measurement event N2 can be defined. Event N2 can be that the measurement result of TD is greater than the length of CP. The corresponding entry conditions for N2 are:

The number of consecutively reported negatives at the physical layer ≥ the third threshold K5,

The leaving conditions are:

The number of continuous reports of the physical layer is ≥ the fourth threshold K6.

Optionally, in the event of triggering, the UE does not trigger a separate report after measuring the first PD. The first network device may add an indication of reporting the first PD result in different reporting configurations. For example, configure an A3 event reporting configuration, and when the signal strength of the second cell reaches the reporting standard of the A3 event, the UE will report the corresponding measurement results related to the second cell. At this time, the first PD measurement result will also be attached to the measurement report. The form of the first PD result may be a specific first PD value, an indication of whether the first PD is smaller than the length of the CP, or the index values of different gears corresponding to the first PD value, etc.

Optionally, a PD-specific measurement event can also be defined. For example, the entry condition of the event is PD≦the first threshold. When the event entry condition is met, the measurement report is triggered, and the UE sends the measurement result of the first PD to the first network device.

Among them, for the first PD report, a new measurement event can be defined. When the first PD measurement result meets the entry condition of the event and meets the trigger time requirement, the measurement report is triggered. When the first PD measurement result meets the leaving condition of the event, the report may also be triggered.

For example, to define a measurement event M2, the event M2 can be that the measurement result of the first PD is less than the first threshold, and the corresponding entry condition of M1 is:

PD1+H2<the first threshold,

The leaving conditions are:

PD1–H2>the first threshold,

Among them, H2 is the second hysteresis value;

PD1 is the first PD.

Optionally, the first network device may send third measurement indication information, and the third measurement indication information may indicate the specific value of the second hysteresis value of the UE.

Optionally, the third measurement indication information may be the first measurement indication information.

Optionally, another PD-specific measurement event can also be defined. The entry condition of the event is that the number of indications reported by the physical layer to the first processing layer exceeds the preset threshold.

For example, to define measurement event N3, event N3 can be that the measurement result of PD is less than the first threshold, and the corresponding entry condition for N3 is:

The number of continuous reports at the physical layer ≥ the fifth threshold K7,

The leaving conditions are:

The number of consecutive no-reports at the physical layer ≥ the sixth threshold K8.

Optionally, a measurement event N4 can be defined. Event N4 can be that the measurement result of the PD is greater than the first threshold. The corresponding entry condition for N4 is:

The number of consecutive no-reports at the physical layer ≥ the fifth threshold K7,

The leaving conditions are:

The number of consecutively reported yes from the physical layer ≥ the sixth threshold K8.

Optionally, the sending module 1203 can also be used to send capability information to the first network device. The capability information is used to indicate that the UE is a single fast Fourier transform FFT processor or a single radio frequency link UE, or the UE has simultaneous connection switching. Or the UE has the ability to measure TD and PD.

Optionally, the processing module 1202 may calculate the first TA, where the first TD is the downlink timing deviation between the first downlink synchronization time point of the first cell and the second downlink synchronization time point of the second cell obtained by the UE. , The calculation process can be:

The first TD is the difference between the first downlink synchronization time point minus the second downlink synchronization time point, or,

The first TD is the absolute value of the difference between the first downlink synchronization time point minus the second downlink synchronization time point, or,

The first TD is the difference between the second downlink synchronization time point minus the first downlink synchronization time point, or,

The first TD is the absolute value of the difference between the second downlink synchronization time point minus the first downlink synchronization time point.

Optionally, the first random access response message includes a second TA, and the second TA is used to determine the uplink sending time of the UE sending information.

Optionally, if the second TA is zero, the method further includes:

The UE sends a handover complete message to the second network device according to the first TA.

Optionally, the second TA is not zero, and the method further includes:

The UE sends first information to the first network device, where the first information is used to instruct the UE to ignore the uplink scheduling authorization information in the first random access response message;

The UE receives second information from the first network device, the second information is used to indicate a third TA, and the third TA is the first common TA of the first cell and the second cell.

Optionally, the first information further includes the second TA.

Optionally, TA is not zero, and the method may also include:

The UE receives third information from the first network device, where the third information is used to indicate the adjustment range of the first TA;

The UE receives fourth information from the second network device, where the fourth information is used to indicate the adjustment range of the second TA;

The UE determines the second public TA according to the third information and the fourth information and sends a handover complete message to the second network device according to the second public TA.

It should be understood that if the UE cannot coordinate the second public TA, there are two processing methods. One is that the UE disconnects from the first cell and the UE uses the second TA to send a handover complete message to the target cell; the other is the UE Cancel the random access process and continue to communicate with the first cell, that is, abandon cell handover and perform traditional handover.

Optionally, the second TA is not zero, and the method may further include: the UE sends a handover complete message to the second network device according to the second TA, and the sum of the second TA and the first TA is the first cell and the second cell. Three public TA.

Optionally, the method may further include: if the first random access response message is not received within the first time after the UE sends the first random access preamble, the UE increases the uplink transmission power and sends the first random access again For the preamble, the increased uplink transmission power is within the first range.

Optionally, the UE receives fifth information, and the fifth information is used to indicate the first range.

It should be understood that when the UE completes the restricted eMBB handover, the UE maintains communication with the first network device and the second network device at the same time, and can terminate the connection with the other network device in the following manner.

Optionally, the receiving module 1201 may receive an instruction message from the second network device to instruct to stop data transmission between the UE and the first cell.

Optionally, the processing module 1202 may also continuously measure the second TD between the first cell and the second cell and the second PD between the first cell and the second cell. When the second TD or the second PD is no longer satisfied As required, the sending module 1203 can report the first network device or the second network device according to the measurement result of the second TD or the second PD, and actively terminate the connection with another network device.

Optionally, the sending module 1203 may send first indication information, the first indication information is used to indicate that the second TD or the second PD does not meet a preset condition, and the first indication information may be an RRC message, for example, by sending a measurement report. The notification to the network device can also be in other message forms, without limitation.

FIG. 13 is a schematic structural diagram of a network device according to an embodiment of the present application.

As shown in FIG. 13, the network device may include a receiving module 1301, a processing module 1302, and a sending module 1303.

The receiving module 1301 may be used to receive first information, the first information is used to instruct the UE to ignore the uplink scheduling authorization information in the first random access response message, and the first network device is the network of the first cell currently accessed by the UE. equipment.

The processing module 1302 may be configured to coordinate with the second network device to determine the third TA, the second network device is the network device of the second cell, and the second cell is the target cell of the UE.

The sending module 1303 may be used to send second information to the UE, the second information is used to indicate a third TA, and the third TA is the first common TA of the first cell and the second cell.

Optionally, the first information further includes a second TA, and the second TA is used to determine the uplink sending time at which the UE sends the information.

Optionally, the first information is sent by the UE or the second network device.

Optionally, when the first information is sent by the second network device, the first information further includes the adjustment range of the second TA.

Optionally, the method may further include: the first network device determines the third TA according to the adjustment range.

Optionally, the method may further include:

The first network device sends coordination request information to the second network device, where the coordination request information is used to instruct the second network device to send the adjustment range of the second TA;

The first network device receives the coordination confirmation information sent by the second network device, and the coordination confirmation information is used to indicate the adjustment range of the second TA.

It should be understood that if the processing module 1302 of the first network device cannot coordinate the first common TA, the sending module 1303 of the first network device station may notify the UE to cancel this handover, or notify the UE to perform a regular handover.

The sending module 1303 may be used to send first measurement indication information, which is used to instruct the UE to measure the first TD and the first PD. The first TD is the TD between the first cell and the second cell, and the first PD It is the PD between the first cell and the second cell, the first network device is the network device of the first cell that the UE currently accesses, and the second network device is the network device of the second cell.

The receiving module 1301 may be configured to receive first measurement result information, where the first measurement result information is used to indicate the measurement result of the first TD; and the first measurement result information is also used to indicate the measurement result of the first PD.

The processing module can be used to determine that the first TD is less than or equal to the CP and the first PD is less than or equal to the first threshold according to the first measurement result information, and then send handover instruction information to the UE. The handover instruction information is used to instruct the UE to send to the second cell Perform cell handover.

Optionally, the receiving module 1301 may also receive capability information from the UE. The capability information is used to indicate that the UE is a UE with a single fast Fourier transform FFT processor or a single radio frequency link, or the UE has the ability to switch connections at the same time, or the UE It has the ability to measure TD and PD.

Optionally, the first measurement indication information includes a first cell list, the first cell list is used to indicate a cell to be measured, and the cell to be measured includes a second cell.

Optionally, the sending module 1303 may send second measurement indication information to the UE, where the second measurement indication information is used to indicate the first hysteresis value H1, and the first hysteresis value is used to indicate a condition for the UE to send the first measurement result information.

For example, the condition for sending the first measurement information may be to define a measurement event M1, and the event M1 may be that the measurement result of the first TD is less than the length of the CP, and the corresponding M1 entry condition is:

TD1+H1<CPlength,

The leaving conditions are:

TD1–H1>CPlength,

Among them, H1 is the first hysteresis value;

TD1 is the first TD.

Optionally, the sending module 1303 may send third measurement indication information to the UE, where the third measurement indication information is used to indicate a second hysteresis value, and the second hysteresis value is used to indicate a condition for the UE to send the first measurement result information.

For example, the condition for sending the first measurement information may be to define a measurement event M2. Event M2 may be that the measurement result of the first PD is less than the first threshold, and the corresponding M1 entry condition is:

PD+H2<the first threshold,

The leaving conditions are:

PD–H2> first threshold,

Among them, H2 is the second hysteresis value;

PD1 is the first PD.

FIG. 14 is a schematic structural diagram of another network device according to an embodiment of the present application.

As shown in FIG. 14, the network device may include a receiving module 1401, a processing module 1402, and a sending module 1403.

Wherein, the receiving module 1401 may be configured to receive sixth information from the first network device, the sixth information is used to indicate the adjustment range of the first TA and the first TA, the first TA is the communication between the UE and the first network device Parameters, the first network device is the network device of the first cell currently accessed by the UE, the second network device is the network device of the second cell, and the second cell is the target cell of the UE.

The receiving module 1401 may also be used to receive the first random access preamble from the UE.

The processing module 1402 may be used to determine the third common advance according to the sixth information.

The sending module 1403 may be used to send a first random access response message to the UE, where the first random access response message is used to indicate the third public TA.

Optionally, the sixth information is handover request information.

It should be understood that if the second network device cannot coordinate the third public TA, that is, the UE cannot use the public TA to establish a connection with the first network device and the second network device at the same time, the second network device may instruct the UE to disconnect from the first network device. Open the connection for traditional handover, or the second network device can determine that the public TA cannot be negotiated based on the sixth information sent by the first network device, then the second network device can indicate in the handover confirmation request that the second network device does not support restricted eMBB switching.

FIG. 15 is a schematic structural diagram of another network device according to an embodiment of the present application.

As shown in FIG. 15, the network device may include a receiving module 1501 and a sending module 1502.

The receiving module 1501 may be used to receive the first random access preamble from the UE, and the second network device is the network device of the second cell to which the UE is handed over.

The sending module 1502 may be configured to send first information to the first network device, where the first information is used to instruct the UE to ignore the uplink scheduling authorization information in the first random access response message, and the first network device is the first network device currently accessed by the UE. The network equipment of the community.

Optionally, the first information further includes a second TA, and the second TA is used to determine the uplink sending time at which the UE sends the information.

Optionally, the first information further includes the adjustment range of the second TA.

Optionally, the receiving module 1501 may be configured to receive coordination request information from the first network device, and the coordination request information is used to instruct the second network device to send the adjustment range of the second TA.

Optionally, the sending module 1502 may be used to send coordination confirmation information to the first network device, and the coordination confirmation information is used to indicate the adjustment range of the second TA.

In another implementation manner, a wireless communication device is provided, and the device can be used to execute the steps of the foregoing method flow. The wireless communication device includes a processor and an interface circuit, and when the processor invokes instructions through the interface circuit, the steps in the above method flow can be executed. The instruction can be stored in a storage medium. The storage medium storing the instructions may be a component of the wireless communication device, or may be located outside the wireless communication device. The wireless communication device may be user equipment, network equipment, or chip device.

FIG. 16 shows a schematic structural diagram of a user equipment provided by an embodiment of the present application. It is used to implement the operation of the user equipment in the above embodiment.

As shown in FIG. 16, the user equipment includes an antenna 810, a radio frequency device 820, and a baseband device 830. The antenna 810 is connected to the radio frequency device 820. In the downlink direction, the radio frequency device 820 receives the information sent by the network device through the antenna 810, and sends the information sent by the network device to the baseband device 830 for processing. In the uplink direction, the baseband device 830 processes the user equipment information and sends it to the radio frequency device 820, and the radio frequency device 820 processes the user equipment information and sends it to the network device via the antenna 810.

The baseband device 830 may include a modem subsystem, which is used to process the various communication protocol layers of data; it may also include a central processing subsystem, which is used to process the terminal operating system and application layer; in addition, it may also include other Subsystems, such as multimedia subsystems, peripheral subsystems, etc., where the multimedia subsystem is used to control the user equipment camera, screen display, etc., and the peripheral subsystem is used to implement connections with other devices. The modem subsystem can be an independent chip. Optionally, the above apparatus for the terminal may be located in the modem subsystem.

The modem subsystem may include one or more processing elements 831, for example, including a main control CPU and other integrated circuits. In addition, the modem subsystem may also include a storage element 832 and an interface circuit 833. The storage element 832 is used to store data and programs, but the program used to execute the method executed by the user equipment in the above method may not be stored in the storage element 832, but stored in a memory outside the modem subsystem. The interface circuit 833 is used to communicate with other subsystems. The above apparatus for user equipment may be located in a modem subsystem, and the modem subsystem may be implemented by a chip. The chip includes at least one processing element and an interface circuit, wherein the processing element is used to perform any of the above user equipment executions. In each step of this method, the interface circuit is used to communicate with other devices. In one implementation, the unit for the user equipment to implement each step in the above method can be implemented in the form of a processing element scheduler. For example, the device for the user equipment includes a processing element and a storage element, and the processing element calls the program stored by the storage element to Perform the method executed by the terminal in the above method embodiment. The storage element may be a storage element whose processing element is on the same chip, that is, an on-chip storage element.

Figure 17 is a schematic structural diagram of a network device provided by an embodiment of the present application. Used to implement the operation of the network device in the above embodiment.

As shown in FIG. 17, the network equipment includes: an antenna 901, a radio frequency device 902, and a baseband device 903. The antenna 901 is connected to the radio frequency device 902. In the uplink direction, the radio frequency device 902 receives the information sent by the terminal through the antenna 901, and sends the information sent by the user equipment to the baseband device 903 for processing. In the downlink direction, the baseband device 903 processes the terminal information and sends it to the radio frequency device 902, and the radio frequency device 902 processes the user equipment information and sends it to the terminal via the antenna 901.

The baseband device 903 may include one or more processing elements 9031, for example, a main control CPU and other integrated circuits. In addition, the baseband device 903 may also include a storage element 9032 and an interface 9033. The storage element 9032 is used to store programs and data; the interface 9033 is used to exchange information with the radio frequency device 902. The interface is, for example, a Common Public Radio Interface (Common Public Radio Interface). , CPRI). The above apparatus for network equipment may be located in the baseband apparatus 903. For example, the above apparatus for network equipment may be a chip on the baseband apparatus 903. The chip includes at least one processing element and an interface circuit, wherein the processing element is used to execute the above network For each step of any method executed by the device, the interface circuit is used to communicate with other devices. In one implementation, the unit for the network device to implement each step in the above method can be implemented in the form of a processing element scheduler. For example, the device for the network device includes a processing element and a storage element, and the processing element calls the program stored by the storage element to Perform the method performed by the network device in the above method embodiment. The storage element may be a storage element with the processing element on the same chip, that is, an on-chip storage element, or a storage element on a different chip from the processing element, that is, an off-chip storage element.

A person of ordinary skill in the art may be aware that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered beyond the scope of this application.

Those skilled in the art can clearly understand that, for the convenience and conciseness of description, the specific working process of the above-described system, device, and unit can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, device, and method may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components can be combined or It can be integrated into another system, or some features can be ignored or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.

In addition, the functional units in each embodiment of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit.

If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the technical solution of this application essentially or the part that contributes to the existing technology or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including Several instructions are used to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disk and other media that can store program code .

The above are only specific implementations of this application, but the protection scope of this application is not limited to this. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in this application. Should be covered within the scope of protection of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims (34)

A method for cell handover, characterized in that the method includes: The user equipment UE determines the first uplink sending moment according to the first timing advance, where the first timing advance is a communication parameter between the UE and the first network device, and the first uplink sending moment is the UE sending the At the moment when the first network device sends information, the first network device is the network device of the first cell currently accessed by the UE; Sending, by the UE, a first random access preamble to a second network device at the first uplink sending moment, the second network device is a network device of a second cell, and the second cell is a target cell of the UE; Receiving, by the UE, a first random access response message in response to the first random access preamble from the second network device; The UE maintains communication with the first network device and the second network device at the same time. The method according to claim 1, wherein the UE also sends first data information to the first network device while sending the first random access preamble. The method according to claim 1 or 2, wherein the method further comprises: The UE sends first measurement result information to the first network device, where the first measurement result information is used to indicate the measurement results of the first downlink timing deviation TD and the first downlink power deviation PD, and the first TD is the TD between the first cell and the second cell, and the first PD is the PD between the first cell and the second cell; The UE receives handover instruction information from the first network device, where the handover instruction information is used to instruct the UE to perform cell handover, wherein the first TD is less than or equal to the length of the cyclic prefix CP, and the first A PD is less than the first threshold. The method of claim 3, wherein the method further comprises: Receiving, by the UE, first measurement indication information sent by the first network device, where the first measurement indication information is used to instruct the UE to measure the first TD and the first PD; The UE measures the first TD and the first PD according to the first measurement indication information. The method according to any one of claims 1 to 4, wherein the method further comprises: The UE sends capability information to the first network device, where the capability information is used to indicate that the UE is a single fast Fourier transform FFT processor or a single radio frequency link UE, or the UE has simultaneous connection switching Or the UE has TD and PD measurement capabilities. The method according to claim 1, wherein the first random access response message includes a second timing advance, and the second timing advance is used to determine the uplink sending time of the UE to send the information. 7. The method of claim 6, wherein the second timing advance is zero, the method further comprises: The UE sends a handover complete message to the second network device according to the first timing advance. 8. The method of claim 6, wherein the second timing advance is not zero, and the method further comprises: Sending, by the UE, first information to the first network device, where the first information is used to instruct the UE to ignore the uplink scheduling authorization information in the first random access response message; The UE receives second information from the first network device, the second information is used to indicate a third timing advance, and the third timing advance is the first cell between the first cell and the second cell. A public time advance. 8. The method of claim 8, wherein the first information further includes the second timing advance. 7. The method of claim 6, wherein the TA is not zero, and the method further comprises: Receiving, by the UE, third information from the first network device, where the third information is used to indicate an adjustment range of the first timing advance; Receiving, by the UE, fourth information from the second network device, where the fourth information is used to indicate an adjustment range of the second timing advance; The UE determines a second common timing advance according to the third information and the fourth information, and sends a handover complete message to the second network device according to the second common timing advance. 8. The method of claim 6, wherein the second timing advance is not zero, and the method further comprises: The UE sends a handover complete message to the second network device according to the second timing advance, and the sum of the second timing advance and the first timing advance is the third common value of the first cell and the second cell. Time advance. The method of claim 1, wherein the method further comprises: If the UE does not receive the first random access response message within the first time after sending the first random access preamble, the UE increases the uplink transmission power and sends the first random access again Enter the preamble, and the increased uplink transmission power is within the first range. The method of claim 12, wherein the UE receives fifth information, and the fifth information is used to indicate the first range. The method according to claim 1, wherein after the UE maintains communication with the first network device and the second network device at the same time, the method further comprises: The UE continues to measure the second TD and the second PD, and when the second TD is greater than the length of the CP or the second PD is greater than the first threshold, the UE ends the communication with the first network device or the second network For device communication, the second TD is a TD between the first cell and the second cell, and the second PD is a PD between the first cell and the second cell. The method according to claim 14, wherein the method further comprises: When the second TD is greater than the length of the CP or the second PD is greater than the first threshold, the UE sends first indication information, where the first indication information is used to indicate that the second TD or the second PD does not satisfy the preset condition. A method for cell handover, characterized in that the method includes: The first network device receives first information, where the first information is used to instruct the UE to ignore the uplink scheduling authorization information in the first random access response message, and the first network device is the first cell currently accessed by the UE Network equipment; The first network device and the second network device coordinate to determine a third timing advance, the second network device is a network device of a second cell, and the second cell is a target cell of the UE; The first network device sends second information to the UE, where the second information is used to indicate the third timing advance, and the third timing advance is the first cell and the second cell The first public time advance. The method according to claim 16, wherein the first information further includes a second timing advance, and the second timing advance is used to determine the uplink transmission time of the UE to send the information. The method according to claim 16 or 17, wherein the first information is sent by the UE or the second network device. The method according to claim 17, wherein the first information is sent by the second network device, and the first information further includes an adjustment range of the second timing advance. The method of claim 19, wherein the method further comprises: The first network device determines the third timing advance according to the adjustment range. The method of claim 16, wherein the method further comprises: Sending, by the first network device, coordination request information to the second network device, where the coordination request information is used to instruct the second network device to send an adjustment range of a second timing advance; The first network device receives coordination confirmation information sent by the second network device, where the coordination confirmation information is used to indicate an adjustment range of the second timing advance. A method for cell handover, characterized in that the method includes: The second network device receives sixth information from the first network device, where the sixth information is used to indicate the first timing advance and the adjustment range of the first timing advance, and the first timing advance is the UE and the first timing advance. A parameter for communication between network devices, the first network device is the network device of the first cell currently accessed by the UE, the second network device is the network device of the second cell, and the second cell is The target cell of the UE; Receiving, by the second network equipment, a first random access preamble from the UE; Determining, by the second network device, a third common advance according to the sixth information; The second network device sends a first random access response message to the UE, where the first random access response message is used to indicate the third common timing advance. The method of claim 22, wherein the sixth information is handover request information. A method for cell handover, characterized in that the method includes: A second network device receives a first random access preamble from a UE, where the second network device is a network device of a second cell to which the UE is handed over; The second network device sends first information to the first network device, where the first information is used to instruct the UE to ignore the uplink scheduling authorization information in the first random access response message, and the first network device is all The network equipment of the first cell that the UE currently accesses. The method according to claim 24, wherein the first information further comprises a second timing advance, and the second timing advance is used to determine the uplink sending time of the UE to send the information. The method according to claim 24, wherein the first information further includes an adjustment range of the second timing advance. The method of claim 25, wherein the method further comprises: The second network device receives coordination request information from the first network device, where the coordination request information is used to instruct the second network device to send an adjustment range of a second timing advance; Coordination confirmation information sent by the second network device to the first network device, where the coordination confirmation information is used to indicate an adjustment range of the second timing advance. A user equipment, characterized in that the user equipment can execute the method according to any one of claims 1 to 15. A network device, characterized in that the network device can execute the method according to any one of claims 16 to 21. A network device, characterized in that the network device can execute the method according to any one of claims 22 or 23. A network device, characterized in that the network device can execute the method according to any one of claims 24 to 27. A network system, characterized in that the network system comprises at least one user equipment according to claim 28, at least one network equipment according to claim 29, and at least one network equipment according to claim 30. A network system, characterized in that, the network system comprises at least one user equipment according to claim 28, at least one network equipment according to claim 29, and at least one network equipment according to claim 31. A computer storage medium, wherein the computer storage medium stores computer-executable instructions, and when called by the computer, the computer-executable instructions are used to cause the computer to execute the claims 1 to 27 Any one of the methods.

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