Cell switching method and related device

Abstract

The invention provides a cell switching method and a related device, in the method, a first network device sends configuration information of an uplink signal to a terminal device, and the configuration information is configuration information of an exclusive uplink signal allocated to the terminal device by a second network device; the terminal equipment sends an uplink signal based on the configuration information; the second network equipment can perform measurement based on the received uplink signal to obtain an uplink measurement result and send the uplink measurement result to the first network equipment; the first network device can determine whether to switch the terminal device to the cell associated with the second network device based on the uplink measurement result, and if the terminal device is determined to switch to the cell, a switching command message is sent to the terminal device to command the terminal device to switch to the cell. Visibly, the pseudo base station cannot know the configuration information of the exclusive uplink signal of the terminal equipment and counterfeit the uplink signal, so that unnecessary switching caused by counterfeit of a downlink broadcast signal by the pseudo base station is avoided, and the success rate of cell switching is improved.

Description

Cell switching method and related device Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a cell switching method and related devices. Background Art

[0002] Currently, the cell handover process is roughly divided into the following stages: terminal equipment measurement, handover decision, handover preparation, and handover execution. Among them, the terminal device measurement phase: the terminal device measures the serving cell and neighboring cells according to the measurement control information sent by the source base station, and reports a measurement report (MR) to the source base station when the measurement results meet the measurement reporting conditions; in the handover decision and preparation phase: the source base station makes a handover decision based on the MR reported by the terminal device and selects a target base station for the terminal device. Then, the source base station sends a handover request message to the target base station. The target base station responds to the handover request message and makes a handover admission judgment. If the terminal device is allowed to switch to the target cell, it replies with a handover request confirmation message to the source base station; in the handover execution phase: the source base station sends a handover command message to the terminal device. After receiving the handover command message, the terminal device synchronizes to the target base station according to the handover command message, initiates a random access process to the target base station, and sends message 1 (MSG1). After receiving MSG1, the target base station replies with message 2 (MSG2) to the terminal device. After receiving MSG2, the terminal device sends a handover confirmation message to the target base station. After receiving the handover confirmation message, the target base station sends a terminal device resource release message to the source base station. At this point, the terminal device handover is completed.

[0003] Among them, during the terminal device measurement phase, the terminal device measures the serving cell and the neighboring cell, mainly based on the synchronization broadcast signal block (SS / PBCH block, SSB) measurement method. Among them, SSB is a bundled design that bundles the primary synchronization signal (PSS) or secondary synchronization signal (SSS), as well as the physical broadcast channel (PBCH) and DMRS for PBCH for simultaneous transmission. The terminal device can achieve downlink frequency and time synchronization with the cell by detecting the PSS or SSS, and obtain the cell identity (such as the physical cell identifier (PCI)).

[0004] However, the cell handover process based on SSB measurement is vulnerable to attacks. For example, if a fake base station forges the downlink frequency, PCI, and SSB information of the target base station, it can induce the source and target base stations to select the target base station's cell as the target cell during the handover decision and preparation phases. However, in reality, the target base station does not meet the handover decision conditions and / or handover admission judgment conditions. For example, the target base station is not adjacent to the source base station, and the terminal device does not enter the coverage area of ​​the target base station. For example, the fake base station's fake SSB transmission power is higher. Although the terminal device enters the coverage area of ​​the target base station, the MSG1 signal is poor and unstable, etc., resulting in the failure of the handover execution phase based on the target cell.

[0005] Therefore, how to avoid counterfeit attacks from fake base stations and improve the success rate of cell switching is an urgent problem to be solved.

[0006] Summary of the Invention

[0007] The present application provides a cell switching method and related devices, which avoid counterfeit attacks by pseudo base stations and improve the success rate of cell switching.

[0008] In a first aspect, the present application provides a cell handover method that can be performed by a communication device, which can be a communication device or a communication device capable of supporting the communication device to implement the functions required by the method, such as a chip. Exemplarily, the communication device is a first network device, or a chip provided in the first network device for implementing the functions of the first network device, or other components for implementing the functions of the first network device. The first network device is used as an example for explanation.

[0009] The method includes: a first network device receives configuration information of an uplink signal from a second network device, and sends the configuration information of the uplink signal to a terminal device, where the configuration information is exclusive uplink signal configuration information allocated by the second network device to the terminal device; receives an uplink measurement result from the second network device, where the uplink measurement result is obtained by the second network device based on measurements of the received uplink signal, where the uplink signal is sent by the terminal device based on the configuration information; and the first network device determines, based on the uplink measurement result, whether to switch the terminal device to the cell of the second network device.

[0010] It can be seen that since the configuration information of the uplink signal is exclusive to the terminal device, it can be sent to the terminal device in a message with encryption and integrity protection information. The pseudo base station cannot know and imitate the exclusive uplink signal, thereby avoiding unnecessary switching caused by the pseudo base station's high-power imitation of the downlink signal, and improving the success rate of the cell switching. In addition, the present application can also reduce a series of other problems caused by the handover failure caused by the pseudo base station impersonation. For example, the terminal is adsorbed on the pseudo base station, resulting in terminal service interruption; or, when the handover failure rate of the legitimate target base station imitated by the pseudo base station is too high and exceeds the threshold, the source base station will add the legitimate target base station to the cell handover blacklist according to the Automatic Neighbor Relation (ANR) feature rule. Even if the pseudo base station has been moved, the legitimate target base station will not be automatically removed from the handover blacklist, affecting the availability of the legitimate target base station; or, the handover failure rate of the terminal device to the legitimate target base station increases, and the source base station will automatically adjust the handover threshold parameter according to the Mobility Robustness Optimization (MRO) function, resulting in more handover failure problems. In addition, in the cell switching method, the uplink measurement result transmitted between the second network device and the first network device is transmitted via the Xn interface, thereby avoiding the overhead of newly added air interface time-frequency resources caused by transmitting the uplink measurement result.

[0011] In an optional implementation, if the first network device determines to switch the terminal device to the cell, a switching command message is sent to the terminal device to instruct the terminal device to switch to the cell of the second network device.

[0012] In an optional embodiment, the first network device also receives uplink synchronization information and uplink resource allocation information from the second network device. The uplink synchronization information is obtained by the second network device through uplink synchronization based on the received uplink signal, and the uplink resource allocation information is used to indicate the uplink resources allocated by the second network device to the terminal device; the switching command message also includes the uplink synchronization information and uplink resource allocation information. It can be seen that the first network device sends the switching command message only after the terminal device and the second network device are uplink synchronized, thereby reducing the switching failure caused by uplink synchronization failure; in addition, the switching command message including uplink synchronization information and uplink resource allocation information is a message with encryption and integrity protection information, thereby ensuring the security of uplink transmission after cell switching; in addition, due to the configuration information of the uplink signal, the terminal device can be synchronized with the second network device through the uplink signal. Therefore, after switching to the cell, it is not necessary to send a random access message, such as message (MSG) 1 for synchronization with the second network device, and the first network device can use the switching command message to send uplink synchronization information and uplink resource allocation information. Therefore, after the terminal device switches to the cell, it is not necessary to send MSG2 for obtaining uplink synchronization information and uplink resource allocation information to the terminal device through the air interface, thereby avoiding the overhead of newly added air interface time-frequency resources and enhancing the air interface transmission security of the uplink synchronization information and uplink resource allocation information.

[0013] In an optional embodiment, the uplink measurement result and the downlink measurement result reported by the terminal device both include the quantized bits of the amplitude and phase of the main eigenvector of the channel between the second network device and the terminal device, or both include the oversampling group index of the space-frequency projection matrix of the channel between the second network device and the terminal device, the index of the angle delay pair selected after the space-frequency projection, and the quantized bits of the projection result of the selected angle delay pair. In this way, the first network device can more accurately detect whether there is a fake base station impersonating the second network device based on the information of the uplink and downlink channels, so as to avoid unnecessary switching caused by the fake base station and improve the success rate of cell switching.

[0014] In another optional embodiment, the uplink measurement result includes a beam index of the uplink optimal beam between the second network device and the terminal device and the corresponding signal strength, signal quality, or signal-to-noise ratio. This facilitates the first network device to determine whether to hand over the terminal device to the cell of the second network device based on this information.

[0015] In another optional embodiment, when the offset between the signal quality of the cell and the signal quality of the serving cell in the uplink measurement result is greater than a preset offset, or the signal quality of the serving cell is lower than a first threshold and the signal quality of the cell is higher than a second threshold, and / or, when the channel correlation of the uplink and downlink measurements obtained based on the uplink measurement result and the downlink measurement result reported by the terminal device meets relevant conditions, it is determined that the terminal device is switched to the cell; or, when the offset between the signal quality of the cell and the signal quality of the serving cell in the uplink measurement result is less than or equal to a preset offset, or the signal quality of the serving cell is not lower than a first threshold, or the signal quality of the cell is not higher than a second threshold, and / or, when the channel correlation of the uplink and downlink measurements obtained based on the uplink measurement result and the downlink measurement result reported by the terminal device does not meet relevant conditions, it is determined not to switch the terminal device to the cell. In this way, on the one hand, the success rate of cell switching is improved by judging the signal quality, and on the other hand, whether there is a fake base station impersonating the second network device is detected by the channel correlation of the uplink and downlink measurements between the second network device and the terminal device, so as to avoid unnecessary switching caused by the fake base station and improve the success rate of cell switching.

[0016] In an optional embodiment, before receiving the uplink signal configuration information from the second network device, the first network device sends a first request indication to the second network device, where the first request indication is used to request the second network device to allocate exclusive uplink signal configuration information to the terminal device; the first network device then receives the uplink signal configuration information from the second network device. Therefore, in this embodiment, the first network device can request the uplink signal configuration information described above from the second network device.

[0017] In another optional embodiment, before the first network device receives the configuration information of the uplink signal from the second network device, the method further includes: the first network device receives the downlink measurement result from the terminal device, the downlink measurement result is obtained by the terminal device performing measurements of the service cell and the neighboring cell based on the downlink measurement control information; the first network device determines the cell to which the terminal device is allowed to switch and the second network device to which the cell belongs based on the downlink measurement result; the first network device sends a second request indication to the second network device, and the second request indication is used to request that the terminal device be switched to the cell. It can be seen that in this embodiment, the first network device can select the cell to which the terminal device is to switch based on the downlink measurement result, and after sending the second request indication to the second network device to which the cell belongs, receive the above-mentioned configuration information of the uplink signal from the second network device.

[0018] In another optional embodiment, before the first network device receives the configuration information of the uplink signal from the second network device, the method further includes: the first network device receives downlink measurement feedback information from the terminal device, the downlink measurement feedback information including the downlink measurement results obtained by the terminal device based on the downlink measurement control information to measure the service cell and the neighboring cell, and the information of the cell selected for switching; the first network device determines whether to allow the terminal device to be switched to the cell based on the downlink measurement results; if it is determined that the terminal device is allowed to be switched to the cell, the first network device sends a second request indication to the second network device, and the second request indication is used to request that the terminal device be switched to the cell. It can be seen that in this embodiment, the downlink measurement feedback information can carry the information of the cell selected by the terminal device for switching, thereby reducing the information of each neighboring cell in the downlink measurement result, which is beneficial to reduce the overhead of air interface time and frequency resources caused by the terminal feedback of the downlink measurement result.

[0019] In another optional implementation, the first network device may send the first request indication and the second request indication mentioned above to the second network device to request that the terminal device be switched to the second network device and the configuration information of the uplink signal mentioned above.

[0020] In a second aspect, the present application further provides a cell handover method, corresponding to the cell handover method described in the first aspect. The method can be performed by a communication device, which can be a communication device or a communication device capable of supporting the communication device to implement the functions required by the method, such as a chip. Exemplarily, the communication device is a terminal device, or a chip provided in the terminal device for implementing the functions of the terminal device, or other components for implementing the functions of the terminal device. The terminal device is used as an example for the execution subject.

[0021] The method includes: a terminal device receives configuration information of an uplink signal from a first network device, where the configuration information is configuration information of an exclusive uplink signal allocated to the terminal device by a second network device, and an uplink measurement result of the uplink signal is used by the first network device to determine whether to switch the terminal device to a cell of the second network device; and the terminal device sends the uplink signal according to the configuration information.

[0022] It can be seen that because the configuration information of the uplink signal is exclusive to the terminal device, the terminal device can obtain the configuration information in the message with encryption and integrity protection information. The pseudo base station cannot learn and imitate the exclusive uplink signal, thereby avoiding unnecessary handovers caused by the pseudo base station's high-power impersonation of the downlink signal, and reducing the impact of the number of handover failures caused by the pseudo base station impersonation on handover failures. For example, the impact of the number of handover failures on handover failures may include the problem of the legitimate cell being impersonated in the ANR being added to the blacklist, and the adjustment of the handover threshold parameters, which may lead to more handover failures.

[0023] In an optional implementation, after the terminal device sends the uplink signal according to the configuration information, the terminal device may receive a handover command message from the first network device, the handover command message being used to instruct the terminal device to switch to a cell; the terminal device performs a cell handover according to the handover command message and sends a handover confirmation message to the second network device. It can be seen that in this implementation, the handover command message received by the terminal device is sent after the first network device determines to switch to the cell of the second network device based on the uplink measurement results. In this way, the terminal device performs a cell handover, avoiding unnecessary handovers caused by fake base station impersonation, thereby improving the success rate of cell handovers.

[0024] In an optional embodiment, the switching command message includes uplink synchronization information and uplink resource allocation information. The uplink synchronization information is obtained by the second network device through uplink synchronization based on the received uplink signal. The uplink resource allocation information is used to indicate the uplink resources allocated by the second network device to the terminal device. It can be seen that in this implementation, the terminal device receives the switching command message only after performing uplink synchronization with the second network device, thereby reducing the switching failure caused by uplink synchronization failure; in addition, the terminal device obtains the uplink synchronization information and uplink resource allocation information through the switching command message with encryption and integrity protection information, thereby ensuring the security of uplink transmission after cell switching; in addition, since the terminal device is synchronized with the second network device through the uplink signal, it is not necessary to send a random access message after switching to the cell, such as the message (MSG) 1 for synchronization with the second network device, and the terminal device obtains the uplink synchronization information and uplink resource allocation information using the switching command message. Therefore, after the terminal device switches to the cell, it is not necessary to obtain MSG2 carrying the uplink synchronization information and uplink resource allocation information through the air interface, thereby avoiding the overhead of newly added air interface time-frequency resources and enhancing the air interface transmission security of the uplink synchronization information and uplink resource allocation information.

[0025] In an optional embodiment, before the terminal device receives the configuration information of the uplink signal from the first network device, the method further includes: the terminal device sends a downlink measurement result to the first network device, the downlink measurement result is obtained by the terminal device based on the downlink measurement control information to measure the serving cell and the neighboring cell, and is used by the first network device to determine the cell to which the terminal device is allowed to switch and the second network device to which the cell belongs. It can be seen that in this embodiment, the terminal device obtains the configuration information of the uplink signal after the first network device makes a switching decision based on the downlink measurement result, which is beneficial for the first network device to determine whether to switch the terminal device to the cell based on the uplink and downlink measurement results, thereby improving the success rate of cell switching.

[0026] In another optional implementation, before the terminal device receives the configuration information of the uplink signal from the first network device, the method further includes: the terminal device sends downlink measurement feedback information to the first network device, the downlink measurement feedback information including the downlink measurement result and the information of the cell selected for switching; the downlink measurement result is obtained by the terminal device by measuring the service cell and the neighboring cell based on the downlink measurement control information, and is used by the first network device to determine whether the terminal device is allowed to switch to the cell, and the network device to which the cell belongs is the second network device. It can be seen that in this implementation, the downlink measurement feedback information can carry the information of the cell selected for switching by the terminal device, thereby reducing the information of each neighboring cell in the downlink measurement result, which is conducive to reducing the overhead of air interface time and frequency resources caused by the terminal feedback of the downlink measurement result.

[0027] In an optional embodiment, the downlink measurement result includes the quantized bits of the amplitude and phase of the main eigenvector of the channel between the second network device and the terminal device, or includes the oversampling group index of the space-frequency projection matrix of the channel between the second network device and the terminal device, the index of the angle delay pair selected after space-frequency projection, and the quantized bits of the projection result of the selected angle delay pair. In this way, the first network device can make appropriate switching decisions based on the uplink and downlink channels between the terminal and the second network device, thereby improving the success rate of cell switching.

[0028] In a third aspect, the present application further provides a cell switching method, corresponding to the cell switching method described in the first and second aspects, which can be performed by a communication device, which can be a communication device or a communication device capable of supporting the communication device to implement the functions required by the method, such as a chip. Exemplarily, the communication device is a second network device, or a chip provided in the second network device for implementing the functions of the second network device, or other components for implementing the functions of the second network device. The second network device is used as the execution subject for example.

[0029] The method includes: the second network device sends configuration information of an uplink signal to the first network device; the configuration information is configuration information of an exclusive uplink signal allocated to the terminal device, and the uplink measurement result of the uplink signal is used by the first network device to determine whether to switch the terminal device to the cell of the second network device; the second network device performs measurement based on the received uplink signal to obtain an uplink measurement result, and the uplink signal is sent by the terminal device based on the configuration information; the second network device sends the uplink measurement result to the first network device.

[0030] It can be seen that since the configuration information of the uplink signal is exclusive to the terminal device, the second network device can send the configuration information in a message with encryption and integrity protection information. The pseudo base station cannot know and imitate the exclusive uplink signal, thereby avoiding unnecessary switching caused by the pseudo base station's high-power imitation of the downlink signal, and reducing the impact of the number of switching failures caused by the pseudo base station impersonation on the switching failure. For example, the impact of the number of switching failures on the switching failure may include more switching failure problems caused by the problem of the cell being added to the blacklist in the ANR and the adjustment of the switching threshold parameters. In addition, the uplink measurement results transmitted between the second network device and the first network device in the cell switching method are transmitted using the Xn port, avoiding the overhead of new air interface time and frequency resources.

[0031] In an optional embodiment, the method further includes: the second network device sends uplink synchronization information and uplink resource allocation information to the first network device, the uplink synchronization information is obtained by uplink synchronization based on the received uplink signal, and the uplink resource allocation information is used to indicate the uplink resources allocated to the terminal device. It can be seen that in this embodiment, the second network device can synchronize with the terminal device based on the uplink signal, which is conducive to reducing the handover failure caused by the inability to synchronize the uplink; in addition, since the second network device synchronizes with the terminal device through the uplink signal, it is beneficial for the terminal device to not need to send a random access message after switching to the cell, such as the message (MSG) 1 used for synchronization with the second network device, and since the second network device can send uplink synchronization information and uplink resource allocation information in advance, after the terminal device switches to the cell, it is not necessary to obtain MSG2 carrying the uplink synchronization information and uplink resource allocation information through the air interface, thereby reducing the overhead of the air interface time and frequency resources.

[0032] In an optional embodiment, the uplink measurement result includes the quantized bits of the amplitude and phase of the main eigenvector of the channel between the second network device and the terminal device, or includes the oversampling group index of the space-frequency projection matrix of the channel between the second network device and the terminal device, the index of the angle delay pair selected after the space-frequency projection, and the quantized bits of the projection result of the selected angle delay pair; and / or, the uplink measurement result includes the beam index of the uplink optimal beam between the second network device and the terminal device and the corresponding signal strength, signal quality or signal-to-noise ratio. In this way, it is beneficial for the first network device to make appropriate switching decisions based on the uplink channel information, avoid unnecessary switching caused by pseudo base stations imitating downlink signals, and thereby improve the success rate of cell switching.

[0033] In an optional embodiment, before the second network device sends the uplink signal configuration information to the first network device, the method further includes: the second network device receiving a first request indication from the first network device, the first request indication being used to request the second network device to allocate exclusive uplink signal configuration information to the terminal device. Thus, in this embodiment, the second network device can send the uplink signal configuration information described above when the first network device requests the configuration information.

[0034] In another optional embodiment, the second network device receives a second request indication from the first network device, the second request indication being used to request handover of the terminal device to the cell; if the second network device allows handover of the terminal device to the cell, the second network device performs the step of sending the uplink signal configuration information to the first network device. It can be seen that in this embodiment, after receiving the second request indication from the first network device, the second network device sends the uplink signal configuration information when it allows handover of the terminal device to the cell.

[0035] In another optional implementation, the second network device may receive the first request indication and the second request indication mentioned above from the first network device to request switching the terminal device to the second network device and the configuration information of the uplink signal mentioned above.

[0036] In the fourth aspect, the present application provides a cell switching method, which corresponds to the cell switching method described in the first to third aspects above, and is explained from the perspective of the interaction between the first network device, the second network device and the terminal device. The beneficial effects of this part can be found in the relevant explanations in the first to third aspects above, and will not be described in detail here.

[0037] The method includes: the second network device sends configuration information of the uplink signal to the first network device, and accordingly, the first network device receives the configuration information of the uplink signal; the first network device sends the configuration information of the uplink signal to the terminal device, the configuration information is the exclusive uplink signal configuration information assigned to the terminal device by the second network device, and the uplink measurement result of the uplink signal is used to determine whether to switch the terminal device to the cell of the second network device; the terminal device sends the uplink signal according to the configuration information; the second network device performs measurement based on the received uplink signal, obtains the uplink measurement result, and sends the uplink measurement result to the first network device, and accordingly, the first network device receives the uplink measurement result and determines whether to switch the terminal device to the cell based on the uplink measurement result.

[0038] In an optional implementation, if the first network device determines to switch the terminal device to the cell, a switching command message is sent to the terminal device, where the switching command message is used to instruct the terminal device to switch to the cell.

[0039] In an optional embodiment, the second network device also sends uplink synchronization information and uplink resource allocation information to the first network device, where the uplink synchronization information is obtained based on uplink synchronization of the received uplink signal, and the uplink resource allocation information is used to indicate the uplink resources allocated to the terminal device; accordingly, the first network device receives the uplink synchronization information and uplink resource allocation information, and includes the uplink synchronization information and uplink resource allocation information in a switching command message; accordingly, the terminal device receives the switching command message, performs cell switching according to the switching command message, and sends a switching confirmation message to the second network device.

[0040] In an optional embodiment, the uplink measurement result and the downlink measurement result reported by the terminal device both include the quantized bits of the amplitude and phase of the main eigenvector of the channel between the second network device and the terminal device, or both include the oversampling group index of the space-frequency projection matrix of the channel between the second network device and the terminal device, the index of the angle delay pair selected after space-frequency projection, and the quantized bits of the projection result of the selected angle delay pair.

[0041] In an optional implementation, the uplink measurement result includes the beam index of the uplink optimal beam between the second network device and the terminal device and the corresponding signal strength, signal quality or signal-to-noise ratio.

[0042] In an optional embodiment, based on the uplink measurement result, determining whether to switch the terminal device to the cell includes: when the offset between the signal quality of the cell and the signal quality of the serving cell in the uplink measurement result is greater than a preset offset, or the signal quality of the serving cell is lower than a first threshold and the signal quality of the cell is higher than a second threshold, and / or when the channel correlation of the uplink and downlink measurements obtained based on the uplink measurement result and the downlink measurement result reported by the terminal device meets relevant conditions, determining to switch the terminal device to the cell; or, when the offset between the signal quality of the cell and the signal quality of the serving cell in the uplink measurement result is less than or equal to a preset offset, or the signal quality of the serving cell is not lower than the first threshold, or the signal quality of the cell is not higher than the second threshold, and / or when the channel correlation of the uplink and downlink measurements obtained based on the uplink measurement result and the downlink measurement result reported by the terminal device does not meet relevant conditions, determining not to switch the terminal device to the cell.

[0043] In an optional embodiment, the first network device sends a first request indication to the second network device, and the first request indication is used to request the second network device to allocate exclusive uplink signal configuration information to the terminal device; accordingly, the second network device receives the first request indication from the first network device and executes the sending of the uplink signal configuration information to the first network device.

[0044] In another optional embodiment, before the first network device receives the configuration information of the uplink signal from the second network device, the method also includes: the terminal device sends a downlink measurement result to the first network device, and accordingly, the first network device receives the downlink measurement result from the terminal device, and the downlink measurement result is obtained by the terminal device performing measurements of the service cell and the neighboring cell based on the downlink measurement control information; the first network device determines the cell to which the terminal device is allowed to be switched and the second network device to which the cell belongs based on the downlink measurement result; the first network device sends a second request indication to the second network device, and the second request indication is used to request that the terminal device be switched to the cell; accordingly, the second network device receives the second request indication, and if the terminal device is allowed to be switched to the cell, executes the step of sending the configuration information of the uplink signal to the first network device.

[0045] In another optional embodiment, before the first network device receives the configuration information of the uplink signal from the second network device, the method also includes: the terminal device sends downlink measurement feedback information to the first network device, and the downlink measurement feedback information includes the downlink measurement result and the information of the selected switching cell; the downlink measurement result is obtained by the terminal device based on the downlink measurement control information to measure the service cell and the neighboring cell, and is used by the first network device to determine whether the terminal device is allowed to switch to the cell, and the network device to which the cell belongs is the second network device; accordingly, the first network device receives the downlink measurement feedback information from the terminal device, and determines whether to allow the terminal device to be switched to the cell based on the downlink measurement result. If it is determined that the terminal device is allowed to be switched to the cell, a second request indication is sent to the second network device, and the second request indication is used to request that the terminal device be switched to the cell; accordingly, the second network device receives the second request indication, and if the terminal device is allowed to be switched to the cell, the step of sending the configuration information of the uplink signal to the first network device is executed.

[0046] In a fifth aspect, the present application provides a communication device, which may be a network device, a device within a network device, or a device capable of being used in conjunction with a network device. The functions of the communication device may be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more units or modules corresponding to the above functions. The units or modules may be software and / or hardware.

[0047] Optionally, the communication apparatus includes a processing unit and a communication unit, and performs the functions of the first network device described in the first aspect, wherein:

[0048] a communication unit, configured to receive configuration information of an uplink signal from a second network device, the configuration information being configuration information of an exclusive uplink signal assigned by the second network device to a terminal device, and an uplink measurement result of the uplink signal being used to determine whether to switch the terminal device to a cell of the second network device; and to send the configuration information of the uplink signal to the terminal device; and to receive an uplink measurement result from the second network device, the uplink measurement result being obtained by the second network device through measurement based on the received uplink signal, the uplink signal being sent by the terminal device based on the configuration information;

[0049] a processing unit, configured to determine whether to switch the terminal device to the cell based on the uplink measurement result;

[0050] The communication unit is further configured to send a switching command message to the terminal device when the processing unit determines to switch the terminal device to the cell, where the switching command message is used to instruct the terminal device to switch to the cell.

[0051] In an optional embodiment, the communication unit is also used to receive uplink synchronization information and uplink resource allocation information from the second network device, the uplink synchronization information is obtained by the second network device through uplink synchronization based on the received uplink signal, and the uplink resource allocation information is used to indicate the uplink resources allocated by the second network device to the terminal device; the switching command message also includes the uplink synchronization information and the uplink resource allocation information.

[0052] In an optional embodiment, the processing unit determines whether to switch the terminal device to the cell based on the uplink measurement result, specifically: when the offset between the signal quality of the cell and the signal quality of the serving cell in the uplink measurement result is greater than a preset offset, or the signal quality of the serving cell is lower than a first threshold and the signal quality of the cell is higher than a second threshold, and / or when the channel correlation of the uplink and downlink measurements obtained based on the uplink measurement result and the downlink measurement result reported by the terminal device meets relevant conditions, it is determined that the terminal device will be switched to the cell; or, when the offset between the signal quality of the cell and the signal quality of the serving cell in the uplink measurement result is less than or equal to a preset offset, or the signal quality of the serving cell is not lower than the first threshold, or the signal quality of the cell is not higher than the second threshold, and / or when the channel correlation of the uplink and downlink measurements obtained based on the uplink measurement result and the downlink measurement result reported by the terminal device does not meet relevant conditions, it is determined not to switch the terminal device to the cell.

[0053] In an optional embodiment, before receiving the configuration information of the uplink signal from the second network device, the communication unit is also used to send a first request indication to the second network device, and the first request indication is used to request the second network device to allocate exclusive uplink signal configuration information to the terminal device.

[0054] In another optional embodiment, before the communication unit receives the configuration information of the uplink signal from the second network device, it is also used to receive the downlink measurement result from the terminal device, and the downlink measurement result is obtained by the terminal device through measurement of the service cell and the neighboring cell based on the downlink measurement control information; the processing unit is also used to determine the cell to which the terminal device is allowed to be switched and the second network device to which the cell belongs based on the downlink measurement result; the communication unit is also used to send a second request indication to the second network device, and the second request indication is used to request that the terminal device be switched to the cell.

[0055] In another optional embodiment, before the communication unit receives the configuration information of the uplink signal from the second network device, it is also used to receive downlink measurement feedback information from the terminal device, the downlink measurement feedback information including the downlink measurement results obtained by the terminal device based on the measurement of the service cell and the neighboring cell based on the downlink measurement control information, and the information of the selected switching cell; the processing unit is also used to determine whether to allow the terminal device to be switched to the cell based on the downlink measurement results; the communication unit is also used to send a second request indication to the second network device if the processing unit determines that the terminal device is allowed to be switched to the cell, and the second request indication is used to request that the terminal device be switched to the cell.

[0056] For other optional implementations and beneficial effects of the communication device, reference may be made to the method and beneficial effects described in the first aspect above.

[0057] Optionally, the communication device performs the function of the second network device described in the third aspect, wherein:

[0058] a communication unit, configured to send configuration information of an uplink signal to a first network device; the configuration information is configuration information of an exclusive uplink signal allocated to the terminal device, and an uplink measurement result of the uplink signal is used by the first network device to determine whether to switch the terminal device to a cell of a second network device;

[0059] The communication unit is further configured to perform measurement based on the received uplink signal to obtain an uplink measurement result, where the uplink signal is sent by the terminal device based on the configuration information;

[0060] The communication unit is further configured to send the uplink measurement result to the first network device.

[0061] In an optional embodiment, the communication unit is also used to send uplink synchronization information and uplink resource allocation information to the first network device, the uplink synchronization information is obtained based on uplink synchronization of the received uplink signal, and the uplink resource allocation information is used to indicate the uplink resources allocated to the terminal device.

[0062] In an optional embodiment, the communication unit is also used to receive a first request indication from the first network device before sending the configuration information of the uplink signal to the first network device, and the first request indication is used to request the second network device to allocate exclusive uplink signal configuration information to the terminal device.

[0063] In an optional embodiment, the communication unit is also used to receive a second request indication from the first network device, and the second request indication is used to request that the terminal device be switched to the cell; if the terminal device is allowed to be switched to the cell, the operation of sending the configuration information of the uplink signal to the first network device is performed.

[0064] For other optional implementations and beneficial effects of the communication device, reference may be made to the method and beneficial effects described in the third aspect above.

[0065] In a sixth aspect, the present application provides a communication device, which may be a terminal device, a device in a terminal device, or a device that can be used in conjunction with a terminal device. The communication device may also be a chip system. The functions of the communication device may be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more units or modules corresponding to the above functions. The units or modules may be software and / or hardware.

[0066] The communication device may execute the cell handover method described in the second aspect, and may include a communication unit, wherein:

[0067] a communication unit, configured to receive configuration information of an uplink signal from a first network device, where the configuration information is exclusive uplink signal configuration information allocated by a second network device to the terminal device, and an uplink measurement result of the uplink signal is used by the first network device to determine whether to hand over the terminal device to a cell of the second network device;

[0068] The communication unit is further configured to send the uplink signal according to the configuration information.

[0069] In an optional embodiment, the communication unit is also used to receive a switching command message from the first network device, wherein the switching command message is used to instruct the terminal device to switch to the cell; and perform cell switching according to the switching command message, and send a switching confirmation message to the second network device.

[0070] In an optional embodiment, the switching command message includes uplink synchronization information and uplink resource allocation information, the uplink synchronization information is obtained by the second network device through uplink synchronization based on the received uplink signal, and the uplink resource allocation information is used to indicate the uplink resources allocated to the terminal device by the second network device.

[0071] In an optional embodiment, the communication unit is also used to send a downlink measurement result to the first network device before receiving the configuration information of the uplink signal from the first network device. The downlink measurement result is obtained by the terminal device by measuring the service cell and the neighboring cell based on the downlink measurement control information, and is used by the first network device to determine the cell to which the terminal device is to be switched and the second network device to which the cell belongs.

[0072] In an optional embodiment, the communication unit is also used to send downlink measurement feedback information to the first network device before receiving the configuration information of the uplink signal from the first network device, wherein the downlink measurement feedback information includes the downlink measurement result and the information of the selected switching cell; the downlink measurement result is obtained by the terminal device by measuring the service cell and the neighboring cell based on the downlink measurement control information, and is used by the first network device to determine that the terminal device is allowed to switch to the cell, and the network device to which the cell belongs is the second network device.

[0073] For other optional implementations and beneficial effects of the communication device, reference may be made to the method and beneficial effects described in the second aspect above.

[0074] Optionally, in the communication device described in the fifth or sixth aspect, the communication unit may be a transceiver, and the processing unit may be a processor. Optionally, the communication device described above may further include a memory for storing instructions or computer programs, and the processor is configured to execute the computer program or instructions stored in the memory, so that the communication device performs any one of the first to third aspects or any optional implementation of any one of the aspects.

[0075] In the seventh aspect, the present application provides a communication device, which may include a processor and an interface circuit, wherein the interface circuit is used to receive signals from other communication devices outside the communication device and transmit them to the processor or send signals from the processor to other communication devices outside the communication device, and the processor is used to implement the method shown in any one of the first to third aspects or any possible implementation methods thereof through a logic circuit or executing code instructions.

[0076] In an eighth aspect, the present application provides a computer-readable storage medium, wherein the storage medium stores instructions. When the computer program or instructions are executed by a communication device, the method shown in any one of the first to third aspects or any possible implementation thereof is implemented.

[0077] In a ninth aspect, the present application provides a computer program product comprising computer instructions, which, when read and executed by a computer, enables the computer to perform the method as shown in any one of the first to third aspects or any possible implementation thereof.

[0078] In the tenth aspect, the present application provides a communication system comprising at least one communication device for executing the method described in the first aspect above, at least one communication device for executing the method described in the second aspect above, and at least one communication device for executing the method described in the third aspect above.

[0079] In an eleventh aspect, the present application provides a circuit, which is coupled to a memory and is used to execute the method as described in any one of the first to third aspects or any possible implementation thereof. The circuit may include a chip circuit.

[0080] In a twelfth aspect, the present application provides a device comprising a module or unit for implementing the method as shown in any one of the first to third aspects or any possible implementation thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] FIG1 is a schematic diagram of a flow chart of a cell handover process;

[0082] FIG2 is a schematic diagram of a pseudo base station attack scenario provided in an embodiment of the present application;

[0083] FIG3 is a schematic diagram of a flow chart of a cell switching process in a pseudo base station attack scenario provided by an embodiment of the present application;

[0084] FIG4 is a schematic diagram of a flow chart of a cell switching method provided in an embodiment of the present application;

[0085] FIG5 is a schematic flow chart of another cell switching method provided in an embodiment of the present application;

[0086] FIG6 is a schematic flow chart of another cell switching method provided in an embodiment of the present application;

[0087] FIG7 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0088] FIG8 is a schematic structural diagram of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0089] In the embodiments of the present application, the network device may also be referred to as an access network device. The access network device may be a device that provides wireless access for a terminal device, and may include a radio access network (RAN) device and an access node (AN) device. RAN devices are mainly wireless network devices in a 3GPP network, and AN devices may be access network devices that are not defined by 3GPP. RAN devices are mainly responsible for wireless resource management, quality of service (QoS) management, data compression and encryption, and other functions on the air interface side. RAN devices may include various forms of base stations, such as macro base stations, micro base stations (also referred to as small stations), relay stations, access points, balloon stations, and the like. In systems using different radio access technologies, the names of devices with base station functions may vary. For example, in long-term evolution (LTE) systems, fifth-generation (5G), sixth-generation (6G), and even seventh-generation (7G) systems, network devices may be called: RAN or next-generation Node basestation (gNB), evolved NodeB (eNB or eNodeB), base station controller (BSC), base transceiver station (BTS), home network device (e.g., home evolved Node B or home Node B, HNB), baseband unit (BBU), access point (AP) in wireless fidelity (WIFI) systems, wireless relay node, wireless backhaul node, transmission and reception point (TRP), transmission point (TP) point, TP), etc.; or one or a group of (including multiple antenna panels) antenna panels of a network device in a 5G system, or it can also be a network node constituting a gNB or transmission point, such as a baseband unit (BBU), or a distributed unit (DU), or a road side unit (RSU) in a vehicle to everything (V2X) or intelligent driving scenario.

[0090] In some deployments, a gNB or transmission point may include a centralized unit (CU) and a DU. A gNB or transmission point may also include a radio unit (RU). The CU implements some of the gNB or transmission point's functions, while the DU implements some of the gNB or transmission point's functions. For example, the CU implements radio resource control (RRC) and packet data convergence protocol (PDCP) layer functions, while the DU implements radio link control (RLC), media access control (MAC), and physical (PHY) layer functions. Because RRC layer information ultimately becomes physical layer information, or is converted from physical layer information, in this architecture, higher-layer signaling, such as RRC layer signaling or PDCP layer signaling, can also be considered to be sent by the DU, or by both the DU and the RU. It is understood that a network device can be a CU node, a DU node, or a device that includes both a CU node and a DU node. Optionally, the network device can also be an auxiliary communication device, such as a satellite.

[0091] In the embodiments of the present application, a terminal device is a device with wireless transceiver capabilities that can be deployed on land, including indoors or outdoors, handheld, wearable, or vehicle-mounted; can also be deployed on water (such as ships); and can also be deployed in the air (such as airplanes, balloons, and satellites). The terminal can be a mobile phone, a tablet computer, a computer with wireless transceiver capabilities, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a vehicle-mounted terminal device, a wireless terminal in self-driving, a wireless terminal in remote medical care, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, a wearable terminal device, and the like. A terminal may also be sometimes referred to as terminal equipment, user equipment (UE), access terminal equipment, vehicle-mounted terminal, industrial control terminal, UE unit, UE station, mobile station, mobile station, remote station, remote terminal equipment, mobile device, UE agent, or UE device, etc. A terminal may also be fixed or mobile.

[0092] The present application can be applied to communication systems of various radio access technologies (RATs), such as LTE communication systems, 5G (or new radio (NR)) communication systems, or transition systems between LTE communication systems and 5G communication systems, which transition systems can also be called 4.5G communication systems. Of course, they can also be future communication systems, such as the sixth generation (6G) or even the seventh generation (7G) system. The network architecture and service scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. It is known to those skilled in the art that with the evolution of communication network architectures and the emergence of new service scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0093] In order to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the related objects before and after are in an "or" relationship.

[0094] To facilitate understanding of the present application, some concepts involved in the embodiments of the present application are explained below.

[0095] 1. Cell switching

[0096] Cell handover, also known as mobile handover or connected mobility management, is the process by which a terminal device operating in a mobile communication system constantly moves from one cell's coverage area to another, requiring the terminal device's communication to remain uninterrupted, i.e., maintaining the physical channel and changing the serving cell. The terminal device is in a Radio Resource Control (RRC) connected state, which can be either synchronized or out-of-sync. When in synchronized state, the terminal device reports its location and identity to the network. The network, based on various policies, ensures that the terminal device maintains the physical channel (i.e., communication remains uninterrupted) and changes the serving cell.

[0097] The cell handover process is roughly divided into the following stages: terminal device measurement, handover decision, handover preparation, and handover execution. For example, as shown in Figure 1, during the terminal device measurement stage:

[0098] 1) The source base station sends measurement control information (Measurement Control) to the terminal device;

[0099] 2) The terminal device performs measurements of the serving cell and neighboring cells according to the measurement control information. When the measurement results meet the measurement reporting conditions, the terminal device reports a measurement report (MR) to the source base station.

[0100] During the handover decision and handover preparation phases:

[0101] 3) The source base station makes a handover decision based on the MR reported by the terminal device and its own radio resource management information, and selects a target base station for the terminal device;

[0102] 4) The source base station sends a handover request message to the target base station;

[0103] 5) The target base station responds to the handover request message and performs handover admission control;

[0104] 6) If the target base station allows the terminal device to be handed over to the target cell, it replies with a Handover Request Acknowledgement message to the source base station;

[0105] During the switch execution phase:

[0106] 7) The source base station sends a handover command message to the terminal device;

[0107] 8) The source base station sends a sequence number status transfer (SN Status Transfer) signaling to the target base station. The SN Status Transfer signaling can convey the uplink packet data convergence protocol (PDCP) sequence number (SN) receiving status information and the downlink PDCP SN sending status information of the user plane data radio bearer (DRB);

[0108] 9) After receiving the handover command message, the terminal device synchronizes to the target base station according to the parameter information carried in the handover command message;

[0109] 10) The terminal device sends message 1 (MSG1) to the target base station, requesting access to the target cell;

[0110] 11) After receiving MSG1, the target base station replies to the terminal device with message 2 (MSG2) carrying the uplink synchronization result and uplink scheduling information;

[0111] 12) After receiving MSG2, the terminal device sends a Handover Confirm message to the target base station;

[0112] 13) After receiving the handover confirmation message, the target base station sends a terminal device resource release message to the source base station. At this point, the terminal device handover is completed.

[0113] In this application, cell handover involves a handover process within the same core network (i.e., the access and mobility management function (AMF) and user plane function (UPF) involved before and after the handover do not change). The handover preparation and execution stages do not require the participation of the core network (such as the 5G core network). For example, the handover preparation messages, such as the Handover Request message and the Handover Request ACK message shown in Figure 1, are directly exchanged between base stations, such as using the communication interface (Xn port) between base stations. Therefore, the cell handover described in this application can also be referred to as Xn port handover.

[0114] In this application, cell handover may include intra-frequency handover and inter-frequency handover. Intra-frequency handover means that the source cell and the target cell to be handed over have the same center frequency and sub-carrier space (SCS), while inter-frequency handover means that at least one of the center frequency and sub-carrier space of the source cell and the target cell to be handed over is different.

[0115] 2. Downlink measurement results, uplink measurement results

[0116] The downlink measurement result is obtained by the terminal device by measuring the serving cell or the neighboring cell according to the measurement control information of the downlink channel or signal sent by the base station (referred to as the downlink measurement control information in this article), and when the downlink measurement result meets the measurement reporting conditions, the terminal device reports the downlink measurement result to the serving cell. Optionally, the downlink measurement result can be reported to the base station in the form of a measurement report. Among them, the definition of the measurement object of the terminal device is different, and the measurement may include: SSB-based co-frequency measurement, that is, the SSB used for measurement in the neighboring cell has the same center frequency and the same SCS as the SSB of the serving cell; SSB-based heterofrequency measurement, that is, the SSB used for measurement in the neighboring cell is different from the SSB of the serving cell in at least one of the center frequencies and SCS.

[0117] The uplink measurement result is obtained by the terminal device sending the uplink channel or signal according to the measurement control information of the uplink channel or signal sent by the base station (which may be called uplink measurement control information), and the network side performing measurements based on the received uplink signal or channel. For example, in the present application, the second network device allocates configuration information of an exclusive uplink signal to the terminal device, and the terminal device can send an uplink signal based on the configuration information, and the second network device can perform measurements based on the received uplink signal to obtain the uplink measurement result.

[0118] During the terminal device measurement phase, the terminal device performs measurements on the serving cell and the neighboring cell, mainly based on the SS / PBCH block (SSB) measurement method or the Channel State Information-Reference Signal (CSI-RS) measurement method. Among them, SSB is a bundled design that bundles the primary synchronization signal (PSS) or the secondary synchronization signal (SSS), as well as the physical broadcast channel (PBCH) and DMRS for PBCH for simultaneous transmission. The terminal device can achieve downlink frequency and time synchronization with the cell by detecting PSS or SSS, and obtain the cell identifier (such as PCI). If a method based on CSI-RS measurement is adopted, the network equipment to which each neighboring cell belongs is required to allocate designated CSI-RS resources to the terminal device, but the number of terminal devices online at the same time in the same cell is too large, and designated CSI-RS resources cannot be allocated to each terminal device. If a method based on SSB measurement is adopted, there is a problem of being easily attacked. For example, a fake base station will imitate the downlink frequency, PCI, SSB and other information of the target base station, inducing the source base station and the target base station to select the cell of the target base station as the target cell during the switching judgment and preparation stage. However, in fact, the target base station does not meet the switching judgment conditions and / or switching access judgment conditions. For example, the target base station is not adjacent to the source base station, and the terminal device has not entered the coverage range of the target base station. For another example, the fake SSB transmission power of the fake base station is greater. Although the terminal device enters the coverage range of the target base station, the signal of MSG1 is poor and unstable, etc., resulting in the failure of the switching execution stage based on the target cell.

[0119] For example, the pseudo base station C replays the broadcast message (such as SSB, Master Information Block (MIB) or System Information Block (SIB) 1) of the legitimate base station B at high power, causing the handover failure rate of the legitimate base station B to increase. For example, the pseudo base station first searches for the PCI of the cell with the strongest signal strength in the existing network and modifies its own PCI to that PCI. When the PCI of the strongest cell in the existing network changes, the pseudo base station can update its own PCI after a period of time and impersonate the PCI and frequency of the legitimate cell with the strongest signal. In this way, the terminal device measures that the SSB signal quality of the pseudo base station C is higher than that of the serving cell and meets the measurement control conditions. It reports the measurement report, and the source base station makes a handover decision and selects the legitimate base station B impersonated by the pseudo base station as the target base station, allowing the terminal device to hand over to the cell of the target base station B. However, after receiving the HO command, the terminal device initiates random access and sends Msg1. Because the terminal device may not be within the coverage area of ​​the target cell B, the target cell B cannot receive Msg1, and the target base station B cannot complete random access with the UE, resulting in the failure of the entire handover. Similarly, this process will cause the handover success rate of all cells near the geographical area where the pseudo base station is located to drop sharply, for example, the handover success rate related to the cell of the impersonated target base station B is very low. After investigation, the staff discovered a fake base station. However, this type of problem requires shutting down the fake base station to solve it, which is difficult to coordinate. Alternatively, a temporary solution is to change the type of neighboring area relationship with the fake base station to "prohibit switching". After the modification, the switching success rate can be restored, but this makes the actual legitimate base station impersonated by the fake base station unavailable.

[0120] Figure 2 shows a schematic diagram of a fake base station attack scenario. In the remote impersonation scenario shown in (a) of Figure 2, legitimate base stations A and B are not geographically adjacent. For example, there is a legitimate base station D in the middle, and a fake base station C impersonates legitimate base station B. Assume that the source base station is legitimate base station A, the PCI of source base station A is 100, and the PCIs of legitimate base station B and fake base station C are 105. The terminal device moves to the overlapping coverage area of ​​source base station A and fake base station C, but is not within the coverage area of ​​legitimate base station B. A possible handover attack process is shown in Figure 3:

[0121] 0) The terminal device performs measurements on the serving cell and neighboring cells based on SSB to obtain downlink measurement results;

[0122] 1) When the downlink measurement result meets the measurement reporting conditions, the terminal device reports the MR to the source base station A. The MR includes the signal quality of the SSB of the pseudo base station C impersonating the legitimate base station B;

[0123] 2) Source base station A makes a handover decision based on the measurement results reported by the terminal device, selects the cell with PCI = 105 as the target cell, and searches the neighbor cell relation table (NCRT) for the target base station B with PCI = 105.

[0124] 3) Source base station A sends a Handover Request message to target base station B;

[0125] 4) After receiving the Handover Request message, the target base station B performs Handover admission control;

[0126] 5) If the terminal device is allowed to switch to the target cell, a Handover Request ACK message is sent to the source base station A;

[0127] 6) After receiving the Handover Request ACK message, the source base station A sends a Handover Command message to the terminal device.

[0128] 7) Source base station A sends SN Status Transfer signaling to target base station B;

[0129] 8) The terminal device responds to the Handover command message to detach from the source base station A and synchronize to the pseudo base station C based on the received broadcast message (including SSB, MIB or SIB1);

[0130] 9) The terminal device sends MSG1 of non-contention random access;

[0131] 10) The pseudo base station C responds to the MSG1 and sends an MSG2, which includes uplink synchronization information and uplink resource allocation information.

[0132] 11) The terminal device receives MSG2 and sends a Handover Confirm message. However, since the terminal device is not within the coverage area of ​​target base station B, target base station B cannot receive MSG1 and Handover Confirm messages sent by the terminal device. Therefore, target base station B considers the handover to have failed and does not send a terminal device resource release message (or terminal device context release message) to source base station A. Accordingly, the source base station determines that the handover has failed because it did not receive the terminal device resource release message.

[0133] For another example, in the near-end spoofing scenario shown in Figure 2 (b), legitimate base stations A and B are geographically adjacent, and a pseudo-base station C is impersonating legitimate base station B. Pseudo-base station C has a different coverage area than legitimate base station B, and its transmit power is greater. When terminal device 1 moves from legitimate base station A to the overlapping coverage area between legitimate base station A and pseudo-base station C, but does not enter the coverage area of ​​legitimate base station B, pseudo-base station C impersonates the SSB of legitimate base station B, causing source base station A to make a handover decision and select legitimate base station B as the target base station. Since terminal device 1 does not actually enter the coverage area of ​​target base station B, the handover attack process shown in Figure 3 is generated, causing the terminal device to fail to handover to target base station B.

[0134] For another example, in the near-end counterfeiting scenario shown in (b) of Figure 2, when the terminal device 2 moves to the coverage overlap area of ​​the legitimate base station A, the legitimate base station B and the pseudo base station C, the source base station A makes a switching decision and selects the legitimate base station B as the target base station. In this case, although the legitimate base station B can receive the MSG1 and send MSG2 to the terminal device, due to the poor and unstable access performance of the uplink Msg1, or the MSG2 is covered and tampered with by the pseudo base station C during the random access process, the subsequent random access fails, which still causes the terminal device to fail to switch to the target base station B.

[0135] Therefore, how to avoid counterfeit attacks from fake base stations and improve the success rate of cell switching is an urgent problem to be solved.

[0136] In the cell switching method provided by the present application, the first network device can send the configuration information of the uplink signal to the terminal device. The configuration information is the configuration information of the exclusive uplink signal assigned to the terminal device by the second network device, and the uplink measurement result of the uplink signal is used to determine whether to switch the terminal device to the cell of the second network device; the first network device determines to switch the terminal device to the cell based on the uplink measurement result of the uplink signal, and then sends a switching command message to the terminal device, instructing the terminal device to switch to the cell. It can be seen that since the configuration information of the uplink signal is exclusive to the terminal device, it can be sent to the terminal device in a message with encryption and integrity protection information. The pseudo base station cannot know and imitate the exclusive uplink signal, thereby avoiding unnecessary switching caused by the pseudo base station's high-power imitation of the downlink signal and improving the success rate of the cell switching.

[0137] The cell switching method provided in this application is described below with reference to the accompanying drawings.

[0138] Please refer to Figure 4, which is a flow chart of a cell switching method provided in an embodiment of the present application. The cell switching method shown in Figure 4 is explained in an interactive manner among a first network device, a second network device, and a terminal device, wherein it is assumed that the first network device is a network device to which the service cell currently accessed by the terminal device belongs, and the second network device is a network device to which the cell to be switched by the terminal device belongs. Optionally, the cell to be switched may be selected by the first network device based on the downlink measurement results reported by the terminal device, or may be selected autonomously by the terminal device based on the downlink measurement results, which is not limited in the embodiment of the present application. Optionally, there may be at least one cell to be switched, and for each cell to be switched, the cell switching method of the embodiment of the present application may be executed, so that the first network device can finally determine the cell to which the terminal device switches. As shown in Figure 4, the cell switching method includes but is not limited to the following steps:

[0139] S101. A second network device sends configuration information of an uplink signal dedicated to a terminal device to a first network device. Correspondingly, the first network device receives the configuration information of the dedicated uplink signal.

[0140] The configuration information is the configuration information of the exclusive uplink signal assigned to the terminal device by the second network device, and the uplink measurement result of the uplink signal is used by the first network device to determine whether to switch the terminal device to the cell of the second network device. Optionally, the configuration information can also be called the configuration information of the switching exclusive uplink signal, and accordingly, the uplink signal can be called the switching exclusive uplink signal. The configuration information of the exclusive (UE specific) uplink signal of the terminal device is allocated by the second network device and is exclusive to the terminal device. The second network device will not allocate it to other terminal devices, and can enable the second network device to accurately obtain the channel state information of the uplink channel between the second network device and the terminal device based on the uplink signal.

[0141] Optionally, before the second network device sends the exclusive uplink signal configuration information to the first network device, the first network device may send a first request indication to the second network device, where the first request indication is used to request the second network device to allocate the exclusive uplink signal configuration information to the terminal device.

[0142] S102. The first network device sends configuration information of an uplink signal dedicated to the terminal device to the terminal device. Correspondingly, the terminal device receives the configuration information of the dedicated uplink signal.

[0143] S103. The terminal device sends the dedicated uplink signal according to the configuration information;

[0144] Optionally, the configuration information of the dedicated uplink signal may be included in a radio resource control (RRC) message or an RRC reconfiguration message, and sent by the first network device to the terminal device. For example, a new information element may be added to the RRC message or the RRC reconfiguration message to indicate the configuration information of the dedicated uplink signal. Optionally, the configuration information may include information such as sequence generation parameters, time-frequency domain resource parameters, and transmit power parameters of the dedicated uplink signal. Optionally, if the uplink signal is a dedicated physical random access channel (PRACH) uplink synchronization signal, the configuration information may be an RRC information element configured by the PRACH (such as RACH-ConfigDedicated).

[0145] S104. The second network device performs measurement based on the received dedicated uplink signal to obtain an uplink measurement result.

[0146] S105. The second network device sends the uplink measurement result to the first network device. Correspondingly, the first network device receives the uplink measurement result.

[0147] S106. The first network device determines whether to switch the terminal device to the cell based on the uplink measurement result.

[0148] In an optional embodiment, the uplink measurement result may include the beam index of the uplink optimal beam between the second network device and the terminal device and the corresponding (such as Reference Signal Receiving Power (RSRP)), signal quality (such as Reference Signal Receiving Quality (RSRQ)) or signal-to-noise ratio (such as Signal to Interference plus Noise Ratio (SINR)). This is helpful for the first network device to determine whether to switch the terminal device to the cell of the second network device based on this information. It can be seen that this embodiment makes a judgment based on the situation of the uplink optimal beam, which is helpful to improve the success rate of cell switching. Among them, the uplink optimal beam is the beam with the strongest receiving energy, such as the largest or strongest RSRQ, RSRP or SINR, among the multiple beams used by the second network device to receive the exclusive uplink signal.

[0149] For example, the first network device determines whether to switch the terminal device to the cell based on the uplink measurement result. The same-frequency A3 event reporting condition and the different-frequency A5 event reporting condition may be used. For example, if the same-frequency A3 event reporting condition is used, if the offset between the signal quality of the cell and the signal quality of the serving cell is greater than the preset offset, the terminal device is determined to be switched to the cell; conversely, if the offset between the signal quality of the cell and the signal quality of the serving cell is less than or equal to the preset offset, the terminal device is determined not to be switched to the cell. For another example, if the different-frequency A5 event reporting condition is used, if the signal quality of the serving cell is lower than the first threshold and the signal quality of the cell is higher than the second threshold, the terminal device is determined to be switched to the cell; if the signal quality of the serving cell is not lower than the first threshold and the signal quality of the cell is not higher than the second threshold, the terminal device is determined not to be switched to the cell.

[0150] In another optional implementation, when the channel correlation of the uplink and downlink measurements obtained based on the uplink measurement result and the downlink measurement result reported by the terminal device meets the relevant conditions, the first network device determines to switch the terminal device to the cell; when the channel correlation of the uplink and downlink measurements obtained based on the uplink measurement result and the downlink measurement result reported by the terminal device does not meet the relevant conditions, the first network device determines not to switch the terminal device to the cell. In this implementation, the first network device can also detect whether the second network device is impersonating a pseudo base station through the correlation of the uplink and downlink measurements, so as to avoid unnecessary switching caused by the pseudo base station and improve the success rate of cell switching.

[0151] In one case, the downlink measurement result reported by the terminal device may also carry the beam index of the downlink optimal beam and the corresponding signal strength, signal quality or signal-to-noise ratio. For example, the downlink optimal beam may be the downlink SSB optimal beam and RSRP, RSRQ, and SINR of the serving cell and the neighboring cell. The relevant conditions that may be satisfied by the channel correlation of the uplink and downlink measurements may include one or more of the following: the beam index of the uplink optimal beam is the same as that of the downlink optimal beam, the difference between the signal strength corresponding to the uplink optimal beam and the signal strength corresponding to the downlink optimal beam is less than a preset value, the offset between the signal quality corresponding to the uplink optimal beam and the signal quality corresponding to the downlink optimal beam is less than a preset offset, and the offset between the signal-to-noise ratio corresponding to the uplink optimal beam and the signal-to-noise ratio corresponding to the downlink optimal beam is less than a preset offset.

[0152] Among them, the beam index of the uplink optimal beam and the downlink optimal beam are the same. For example: the terminal device receives multiple downlink SSBs sent by the second network device, among which the RSRP of SSB index 3 is the strongest. Assuming that SSB index 3 corresponds to SSB transmission beam 3, the terminal device notifies the first network device of the SSB index with the strongest reception RSRP of the second network device; the second network device receives the exclusive uplink signal sent by the terminal device, and the second network device uses multiple SSB transmission beams to perform reception beam domain processing of the uplink signal. Assuming that the reception energy of the uplink signal is also the strongest under beam index 3, the second network device will inform the first network device of the optimal reception beam index (i.e., beam index 3) of the uplink signal based on the uplink measurement result; in this way, the first network device determines that the optimal beam indexes of the uplink and downlink measurements between the terminal device and the second network device are the same, then it can make a switching decision, i.e., determine to switch the terminal device to the cell of the second network device.

[0153] In another case, the uplink measurement result and the downlink measurement result reported by the terminal device both include quantized bits of the amplitude and phase of the main eigenvector of the channel between the second network device and the terminal device.

[0154] The method for calculating the quantized bits of the amplitude and phase of the main eigenvector of the channel in the downlink measurement result includes:

[0155] 1) The terminal device calculates the equivalent channel based on the optimal beam of SSB

[0156]

[0157] Among them, W SSB is the optimal beam for SSB, H i is the air interface channel H at time i;

[0158] 2) The terminal device calculates the channel measurement mean of a specific sub-band or the entire band based on the equivalent channel at time i

[0159] 3) The terminal device measures the mean value based on the channel Calculate the covariance matrix R hh :

[0160]

[0161] in, is the channel measurement mean The transpose of

[0162] 4) The terminal device is based on the covariance matrix R hh The eigenvector matrix V is obtained by the following formula:

[0163] EVD(R hh )=VΛV H (3)

[0164] Among them, EVD represents the algorithm formula for eigenvalue decomposition, and the first column of V is the main eigenvector V0;

[0165] 5) The terminal device performs N-bit quantization on the amplitude and phase of each element of V0 to obtain the quantization bits of the amplitude and phase of the main eigenvector, where N is a positive integer configured by the upper layer.

[0166] Thus, the downlink measurement results reported by the terminal device may include the quantized bits of the amplitude and phase of the main eigenvector of the downlink channel. Correspondingly, the second network device may determine the quantized bits of the amplitude and phase of the main eigenvector of the uplink channel through the above steps 1) to 5) based on the optimal beam of the uplink signal, which will not be described in detail here.

[0167] Accordingly, the channel correlation of uplink and downlink measurements can be calculated based on the main eigenvector of the uplink channel and the main eigenvector of the downlink channel, such as using V UL represents the main eigenvector of the uplink channel, V DL represents the main eigenvector of the downlink channel, then the channel correlation Corr of the uplink and downlink measurements is:

[0168]

[0169] Among them, 0.0<=Corr<=1.0. The smaller the Corr, the worse the channel correlation of the uplink and downlink channels, and the greater the possibility of a fake base station impersonation.

[0170] In this case, the channel correlation of the uplink and downlink measurements can satisfy a channel correlation threshold of Corr_Thread = 0.9, that is, the first network device will determine to switch the terminal device to the cell of the second network device only when the channel correlation is greater than Corr_Thread. In addition, this situation can be applied to systems with high reciprocity, such as time division duplexing (TDD) systems.

[0171] In another case, the uplink measurement result and the downlink measurement result reported by the terminal device both include the oversampling group index of the space-frequency projection matrix of the channel between the second network device and the terminal device, the index of the angle delay pair selected after the space-frequency projection, and the quantization bits of the projection result of the selected angle delay pair.

[0172] Among them, the oversampling group index of the space-frequency projection matrix of the channel in the downlink measurement result, the index of the angle delay pair selected after the space-frequency projection, and the quantization bit of the projection result of the selected angle delay pair can be obtained by using but not limited to the following steps:

[0173] 1) The terminal device calculates the main eigenvectors of multiple sub-bands based on the above formulas (1) to (3), where the main eigenvector of a single sub-band is Among them, v 0,V ,v 0,H Represents the components of v0 in the vertical and horizontal polarization directions, N p is the number of ports of the network device, C is the complex vector space;

[0174] 2) The terminal device combines the main eigenvectors of multiple sub-bands to obtain the space-frequency matrix H = [v 0 … vSB_num_WB-1], SB_num_WB is the number of subbands;

[0175] 3) The terminal device performs space-frequency dual-domain compression projection on the space-frequency matrix H by traversing the basis vectors of different space-domain and frequency-domain oversampling groups, as shown in the following formula (5):

[0176]

[0177] in, represents the channel measurement mean, From the spatial basis vector oversampling group, there are O1O2 spatial oversampling groups, q1=0,1,…,O1-1; q2=0,1,…,O2-1, each group contains Np / 2 dimensional spatial basis vector, i.e. From the frequency domain basis vector oversampling group, the frequency domain oversampling group has O3 groups, q3 = 0, 1, ..., O3-1, each group contains N3 = SB_num_WB SB_num_WB x1 frequency domain basis vectors, that is Among them, the spatial basis matrix and frequency domain basis matrix It is obtained by determining the corresponding oversampling group index (q1q2, q3) based on the principle of maximizing the energy and time delay of the projected angle pair;

[0178] 4) The terminal device selects the basis row and column index of the space-frequency projection matrix with stronger energy angle and delay after space-frequency projection That is, the index of the angle-delay pair with stronger energy selected after space-frequency projection; wherein the angle-delay pair with stronger energy may be an angle-delay pair with energy greater than a certain threshold, and the threshold may be predefined or signaled;

[0179] 5) According to the basis row and column index of the space-frequency projection matrix Take out the corresponding projection results to form the combination coefficient matrix C l , quantize the amplitude and phase of the elements to obtain the combination coefficient matrix C l The quantized amplitude and phase of the elements in are the quantized bits of the response result of the selected angle-time delay pair. Here, s represents the spatial domain, f represents the frequency domain, L represents the index number of angles with stronger energy, and K represents the index number of delays with stronger energy.

[0180] In this way, the downlink measurement result may include: the oversampling group index of the space-frequency projection matrix of the downlink channel between the terminal device and the second network device, the index of the angle delay pair selected after space-frequency projection, and the quantized bits of the projection result of the selected angle delay pair. Accordingly, the second network device may also calculate the uplink measurement result based on the received uplink signal using the method described in steps 1) to 5) above. The uplink measurement result may also include the oversampling group index of the space-frequency projection matrix of the uplink channel between the terminal device and the second network device, the index of the angle delay pair selected after space-frequency projection, and the quantized bits of the projection result of the selected angle delay pair.

[0181] Optionally, the first network device uses the information of the uplink channel and the downlink channel to perform weight reconstruction, and obtains the eigenvector matrix V of the uplink channel and the downlink channel respectively. UL and V DL . Furthermore, the first network device can calculate the channel correlation using the above formula (4). Accordingly, the relevant condition that the channel correlation of the uplink and downlink measurements can meet can be the channel correlation threshold Corr_Thread=0.8, that is, the first network device will determine to switch the terminal to the cell of the second network device only when the channel correlation Corr is greater than Corr_Thread; conversely, when the channel correlation Corr is less than or equal to Corr_Thread, the first network device determines not to switch the terminal to the cell of the second network device. Optionally, this situation has lower requirements for the reciprocity of the uplink and downlink channels, such as being applicable to frequency division duplexing (FDD) deployment, TDD deployment (which does not have complete reciprocity), or multi-station (multi-TRP) transmission.

[0182] Optionally, the first network device may compare the oversampling group index of the space-frequency projection matrix of the uplink channel and the index of the angle delay pair selected after the space-frequency projection with the oversampling group index of the space-frequency projection matrix of the downlink channel and the index of the angle delay pair selected after the space-frequency projection. If they are partially or completely the same, it can be determined that the channel correlation of the uplink and downlink measurements meets the relevant conditions, and then determine to switch the terminal device to the cell of the second network device; otherwise, it can be determined that the channel correlation of the uplink and downlink measurements does not meet the relevant conditions, and then determine not to switch the terminal device to the cell of the second network device.

[0183] Optionally, the first network device may compare the oversampling group index of the space-frequency projection matrix of the uplink channel and the index of the angle delay pair selected after the space-frequency projection with the oversampling group index of the space-frequency projection matrix of the downlink channel and the index of the angle delay pair selected after the space-frequency projection, and use the eigenvector matrix V of the uplink channel UL and the eigenvector matrix V of the downlink channel DL Calculate the channel correlation. If the oversampling group index of the space-frequency projection matrix of the uplink channel and the index of the angle delay pair selected after the space-frequency projection are partially or completely the same as the oversampling group index of the space-frequency projection matrix of the downlink channel and the index of the angle delay pair selected after the space-frequency projection, and the calculated channel correlation is greater than the channel correlation threshold, then it is determined that the channel correlation of the uplink and downlink measurements meets the relevant conditions, and it can be determined that the terminal will be switched to the cell of the second network device; conversely, if the oversampling group index of the space-frequency projection matrix of the uplink channel and the index of the angle delay pair selected after the space-frequency projection are all different from the oversampling group index of the space-frequency projection matrix of the downlink channel and the index of the angle delay pair selected after the space-frequency projection, or the calculated channel correlation is less than or equal to the channel correlation threshold, then it is determined that the channel correlation of the uplink and downlink measurements does not meet the relevant conditions, and then, it is determined not to switch the terminal device to the cell of the second network device.

[0184] In another optional implementation, when the offset between the signal quality of the cell and the signal quality of the serving cell in the uplink measurement result is greater than the preset offset, or the signal quality of the serving cell is lower than the first threshold and the signal quality of the cell is higher than the second threshold, and the channel correlation of the uplink and downlink measurements obtained based on the uplink measurement result and the downlink measurement result reported by the terminal device meets the relevant conditions, it is determined that the terminal device is switched to the cell; when the offset between the signal quality of the cell and the signal quality of the serving cell in the uplink measurement result is less than or equal to the preset offset, or the signal quality of the serving cell is not lower than the first threshold, or the signal quality of the cell is not higher than the second threshold, or the channel correlation of the uplink and downlink measurements obtained based on the uplink measurement result and the downlink measurement result reported by the terminal device does not meet the relevant conditions, it is determined not to switch the terminal device to the cell. In this way, on the one hand, the success rate of cell switching is improved by judging the signal quality, and on the other hand, the channel correlation of the uplink and downlink measurements is used to detect whether the second network device is counterfeited by a pseudo base station, so as to avoid unnecessary switching caused by a pseudo base station and improve the success rate of cell switching. Specifically, the channel correlation and the conditions that need to be met by the channel correlation in this implementation can be referred to the relevant content described in the previous embodiment, which will not be described in detail here.

[0185] It can be seen that in the cell switching method, since the configuration information of the uplink signal is exclusive to the terminal device, it can be sent to the terminal device in a message with encryption and integrity protection information. The pseudo base station cannot know and imitate the exclusive uplink signal, thereby avoiding unnecessary switching caused by the high-power imitation of the downlink signal by the pseudo base station, and improving the success rate of cell switching. In addition, the present application can also reduce the impact of the number of switching failures caused by the impersonation of the pseudo base station on the switching failure. For example, the impact of the number of switching failures on the switching failure may include more switching failure problems caused by the problem of the cell being added to the blacklist in the ANR and the adjustment of the switching threshold parameters. In addition, in the cell switching method, the uplink measurement results transmitted between the second network device and the first network device are transmitted using the Xn port, avoiding the overhead of new air interface time-frequency resources. In addition, in the method, the optional implementation method in which the first network device determines whether to switch the terminal device to the cell of the second network device is conducive to further improving the success rate of cell switching.

[0186] In an optional embodiment, the cell switching method shown in Figure 4, in addition to including the above-mentioned steps S101 to S106, if it is determined to switch the terminal device to the cell, the cell switching method may also include the relevant operations of the switching execution phase described in steps 7) to 13) shown in Figure 1, which are not described in detail here; if it is determined not to switch the terminal device to the cell, the first network device may send a switching cancellation message to the second network device.

[0187] In another optional embodiment, the cell switching method shown in Figure 4, in addition to including the above-mentioned steps S101 to S106, if it is determined to switch the terminal device to the cell, the cell switching method may also include steps S107 to S110 as shown in Figure 4; if it is determined not to switch the terminal device to the cell, the first network device may send a switching cancellation message to the second network device.

[0188] S107. The first network device sends a switching command message to the terminal device. Correspondingly, the terminal device receives the switching command message; wherein the switching command message includes uplink synchronization information and uplink resource allocation information.

[0189] In this embodiment, the configuration information of the dedicated uplink signal may be the configuration information of MSG1 in the process of random access initiated by the terminal device, such as the configuration information may include information such as sequence generation parameters, time-frequency domain resource parameters, and transmission power parameters of PRACH. Optionally, if the uplink signal is a dedicated PRACH uplink synchronization signal, the configuration information may be the RRC information element RACH-ConfigDedicated configured by the PRACH. In step S103, the uplink signal sent by the terminal device according to the configuration information may be MSG1. In this way, in step S104, in addition to obtaining an uplink measurement result by measuring the received uplink signal, the second network device may also perform uplink synchronization with the terminal device based on the received uplink signal, obtain uplink synchronization information, and allocate uplink resource allocation information to the terminal device. Optionally, the uplink synchronization information may be the value of the uplink timing advance (TA), and the uplink resource allocation information is used to indicate the uplink resources allocated by the second network device to the terminal device. In step S105 , in addition to sending the uplink measurement result to the first network device, the second network device may also send the uplink synchronization information and uplink resource allocation information.

[0190] Optionally, the uplink measurement result, uplink synchronization information and uplink resource allocation information may be carried in a handover measurement feedback message, and sent by the second network device to the first network device through the Xn port.

[0191] S108. The terminal device performs cell switching according to the switching command message;

[0192] The terminal device performs a cell handover based on the handover command message, which may include: the terminal device detaching from the first network device and synchronizing to the second network device based on the received cell information. Because the terminal device has already obtained uplink synchronization information and uplink resource allocation information through the handover command message, it is not necessary to send MSG2 as shown in Figure 1, reducing signaling interaction and, in turn, reducing air interface time and frequency resource overhead.

[0193] S109. The terminal device sends a handover confirmation message to the second network device. Correspondingly, the second network device receives the handover confirmation message.

[0194] S110: The second network device sends a terminal device resource release message to the first network device. Correspondingly, the first network device receives the terminal device resource release message. The first network device may then release the context information of the terminal device. Thus, the terminal device completes the cell handover.

[0195] It can be seen that in this embodiment, the first network device sends the switching command message only after the terminal device and the second network device are synchronized uplink, thereby reducing the switching failure caused by the inability to synchronize uplink. In addition, the uplink synchronization information and the uplink resource allocation information are sent to the terminal device through the switching command message. Since the switching command message is an RRC reconfiguration message with encryption and integrity protection information, the security of the uplink transmission after the cell switching is guaranteed. In addition, since the terminal device is synchronized with the second network device through the dedicated uplink signal, it is not necessary to send a random access message after switching to the cell, such as the message (MSG) 1 for synchronization with the second network device, and the first network device can use the switching command message to send uplink synchronization information and uplink resource allocation information. Therefore, after the terminal device switches to the cell, it is not necessary to send MSG2 for obtaining uplink synchronization information and uplink resource allocation information to the terminal device through the air interface, thereby reducing the overhead of the air interface time and frequency resources.

[0196] Please refer to Figure 5, which is a flow chart of another cell switching method provided by an embodiment of the present application. The difference between the cell switching method shown in Figure 5 and the cell switching method described in Figure 4 is that in the cell switching method shown in Figure 5, the cell of the second network device is the target cell selected by the first network device to allow the terminal device to switch based on the downlink measurement result reported by the terminal device. Correspondingly, the second network device is also the target network device found by the first network device based on the information of the target cell (such as the base station corresponding to the PCI of the target cell found from the NCRT). As shown in Figure 5, the cell switching method may include but is not limited to the following steps:

[0197] S201. A first network device sends downlink measurement control information to a terminal device. Correspondingly, the terminal device receives the downlink measurement control information.

[0198] S202. The terminal device measures the serving cell and the neighboring cell based on the downlink measurement control information to obtain a downlink measurement result.

[0199] S203. When the downlink measurement result meets the reporting condition, the terminal device reports an MR to the first network device, where the MR includes the downlink measurement result. Accordingly, the first network device receives the MR.

[0200] As mentioned above, the downlink measurement result may include the beam index of the downlink optimal beam and the corresponding signal strength, signal quality or signal-to-noise ratio. In one case, the downlink measurement result may meet the reporting condition of the same-frequency A3 event reporting condition, that is, the offset between the signal quality of the neighboring cell and the signal quality of the serving cell is greater than the preset offset, then, it can be determined that the downlink measurement result meets the reporting condition; conversely, if the offset between the signal quality of the neighboring cell and the signal quality of the serving cell is less than or equal to the preset offset, then, it can be determined that the downlink measurement result does not meet the reporting condition. In another case, the downlink measurement result may meet the reporting condition of the different-frequency A5 event reporting condition, that is, the signal quality of the serving cell is lower than the first threshold, and the signal quality of the neighboring cell is higher than the second threshold, it can be determined that the downlink measurement result meets the reporting condition; if the signal quality of the serving cell is not lower than the first threshold, and the signal quality of the neighboring cell is not higher than the second threshold, it is determined that the downlink measurement result does not meet the reporting condition.

[0201] Optionally, in addition to the above-mentioned intra-frequency A3 event reporting condition and inter-frequency A5 event reporting condition, the reporting condition can be set by the first network device in the downlink measurement control information, which is not limited in this embodiment of the present application.

[0202] S204. The first network device determines, according to the downlink measurement result, a target cell to which the terminal device is allowed to switch and a second network device to which the target cell belongs;

[0203] In the present application, as described above, in addition to the relevant information of the optimal beam of each neighboring cell, the downlink measurement results may also include new downlink channel information, such as the quantized bits of the amplitude and phase of the main eigenvector of the channel between the network device and the terminal device of each neighboring cell as described above, and / or the oversampling group index of the channel's space-frequency projection matrix, the index of the angle delay pair selected after the space-frequency projection, and the quantized bits of the projection result of the selected angle delay pair. Accordingly, the first network device may make a switching decision based on one or more information in the downlink measurement results, select the target cell and the second network device to which the target cell belongs, which will not be described in detail here.

[0204] S205. The first network device sends a second request indication to the second network device, where the second request indication is used to request handover of the terminal device to the target cell; accordingly, the second network device receives the second request indication;

[0205] Optionally, the second request indication may be carried in the Handover Request message shown in Figure 1. Optionally, the Handover Request message may further include a first request indication for requesting the configuration information of the dedicated uplink signal mentioned above.

[0206] S206. The second network device sends configuration information of a dedicated uplink signal to the first network device after allowing the terminal device to be handed over to the target cell. Correspondingly, the first network device receives the configuration information of the dedicated uplink signal.

[0207] Among them, the second network device can use the handover admission judgment of step 5) described in Figure 1 to determine whether to allow the terminal device to switch to the target cell. For example, the second network device determines whether to allow the terminal device to access the target cell based on its own load conditions and the service quality (Quality of Service, QOS) requirements of the business. If the terminal device is allowed to access the target cell, a dedicated admission resource is allocated to the terminal device so that the terminal device can access the target cell based on the admission resource, such as the admission resource can be a resource for sending the exclusive uplink signal. Optionally, the configuration information of the exclusive uplink signal can be carried in the Handover Request ACK message described in Figure 1.

[0208] S207. The first network device sends the configuration information of the dedicated uplink signal to the terminal device. Correspondingly, the terminal device receives the configuration information of the dedicated uplink signal.

[0209] S208. The terminal device sends the dedicated uplink signal according to the configuration information;

[0210] S209. The second network device performs measurement based on the received dedicated uplink signal to obtain an uplink measurement result.

[0211] S210. The second network device sends the uplink measurement result to the first network device. Correspondingly, the first network device receives the uplink measurement result.

[0212] S211. The first network device determines whether to switch the terminal device to the target cell based on the uplink measurement result.

[0213] Among them, steps S206 to S211 can refer to the optional implementation of steps S101 to S106 above, and will not be described in detail here. Among them, in the optional implementation of step S211, the first network device determines whether to switch the terminal device to the target cell based on the uplink measurement result, or based on the uplink measurement result and the downlink measurement result, and the downlink measurement result is obtained in step S202.

[0214] Optionally, the handover decision described in step S204 can be referred to as a primary handover decision, and the determination of whether to handover the terminal device to the target cell described in step S211 can be referred to as a secondary handover decision. The difference between the two is that the primary handover decision is based on the downlink measurement results, while the secondary handover decision is based on the uplink measurement results, or based on both the uplink and downlink measurement results. For details, please refer to the relevant content described above and will not be detailed here.

[0215] Optionally, in this embodiment, after the first network device determines to switch the terminal device to the target cell, an optional implementation method may execute steps 7) to 13) shown in Figure 1 as described above; another optional implementation method may execute steps S107 to S110 shown in Figure 4 as described above, which will not be described in detail here. Figure 5 takes the execution of steps S107 to S110 shown in Figure 4 as an example, corresponding to steps S212 to S215 in Figure 5, which will not be described in detail here.

[0216] It can be seen that in the cell handover method shown in Figure 5, after the first network device allows the terminal device to switch to the target cell, it will make a handover decision again based on the uplink measurement result measured by the second network device. Since the uplink measurement result is obtained based on the uplink signal measurement exclusive to the terminal device, it can avoid being impersonated by a pseudo base station, thereby improving the security of the cell handover. In addition, in an optional embodiment, the second network device and the terminal device can also perform uplink synchronization based on the uplink signal before sending a handover command message, which can reduce handover failures caused by uplink synchronization failure. In addition, the uplink measurement result obtained by the first network device is transmitted by the second network device through the interface between the network devices, which can avoid adding new air interface time and frequency overhead. In an optional embodiment, the handover command message carries uplink synchronization information and uplink resource allocation information, which can ensure the security of uplink transmission after handover. In an optional embodiment, the first network device can use the uplink and downlink channel correlation to make a decision in the second decision. Since a pseudo base station can only impersonate the downlink channel but cannot impersonate the uplink channel, it can more accurately detect whether there is a pseudo base station impersonation between the second network device and the terminal device.

[0217] Please refer to Figure 6, which is a schematic flow chart of another cell handover method provided in an embodiment of the present application. The cell handover method shown in Figure 6 differs from the cell handover method shown in Figure 5 in that, in the cell handover method shown in Figure 6, the cell of the second network device is selected by the terminal device itself, such as a target cell selected from a neighboring cell based on downlink measurement results. Optionally, the target cell requested for handover can be carried in an MR sent by the terminal device to the first network device, or can be carried in a handover request message sent by the terminal device to the first network device. Since the terminal device can report its own target cell requested for handover to the first network device, the MR or the handover request message can carry measurement results of the serving cell and the target cell, reducing the number of neighboring cell measurement results required, thereby reducing the required air interface time-frequency resource overhead. Specifically, as shown in Figure 6, the cell handover method may include steps S301 to S314, where S301, S302, and S304 to S314 correspond to steps S205 to S215 in Figure 5 and are not described in detail here. For details, please refer to the relevant content described in Figure 5. S303. The terminal device sends a MR or a handover request message to the first network device, where the MR or the handover request message includes a target cell selected by the terminal device.

[0218] It can be seen that in this implementation, the downlink measurement feedback information can carry information about the cell selected by the terminal device for switching, thereby reducing the information of each neighboring cell in the downlink measurement results, and thus helping to reduce the overhead of air interface time and frequency resources caused by the terminal feedback of the downlink measurement results.

[0219] It is understood that in order to implement the functions in the above embodiments, the network devices and terminal devices include hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily appreciate that, in combination with the units and method steps of each example described in the embodiments disclosed in this application, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in hardware or in a manner driven by computer software depends on the specific application scenario and design constraints of the technical solution.

[0220] Figures 7 and 8 are schematic diagrams of the structures of possible communication devices provided in the embodiments of the present application. These communication devices can be used to implement the functions of the network device or terminal device in the above-mentioned method embodiments, and thus can also achieve the beneficial effects possessed by the above-mentioned method embodiments. In the embodiments of the present application, the communication device can be any possible terminal device with wireless transceiver functions as described above, or any possible network device capable of providing wireless access for the terminal device as described above, or a module (such as a chip) applied to the network device or terminal device.

[0221] As shown in FIG7 , the communication device includes a processing unit 410 and a communication unit 420. The communication device is used to implement the functions of each network device or terminal device in any of the embodiments shown in FIG4 to FIG6 and their implementation methods. For example:

[0222] When the communication device is used to implement the function of the first network device in the method embodiments shown in FIG. 4 to FIG. 6 :

[0223] a communication unit 420 configured to receive configuration information of an uplink signal from a second network device, and send the configuration information of the uplink signal to the terminal device, where the configuration information is exclusive uplink signal configuration information assigned by the second network device to the terminal device, and an uplink measurement result of the uplink signal is used to determine whether to switch the terminal device to the cell of the second network device; and receive an uplink measurement result from the second network device, where the uplink measurement result is obtained by the second network device based on a measurement of the received uplink signal, where the uplink signal is sent by the terminal device based on the configuration information;

[0224] The processing unit 410 is configured to determine whether to switch the terminal device to the cell based on the uplink measurement result;

[0225] The communication unit 420 is configured to send a handover command message to the terminal device to instruct the terminal device to handover to the cell if the processing unit 410 determines to handover the terminal device to the cell.

[0226] In an optional embodiment, the communication unit 420 is also used to receive uplink synchronization information and uplink resource allocation information from the second network device, and the uplink synchronization information is obtained by the second network device through uplink synchronization based on the received uplink signal, and the uplink resource allocation information is used to indicate the uplink resources allocated by the second network device to the terminal device; the switching command message also includes the uplink synchronization information and uplink resource allocation information.

[0227] In an optional embodiment, the uplink measurement results and the downlink measurement results reported by the terminal device both include the quantized bits of the amplitude and phase of the main eigenvector of the channel between the second network device and the terminal device, or both include the oversampling group index of the space-frequency projection matrix of the channel between the second network device and the terminal device, the index of the angle delay pair selected after the space-frequency projection, and the quantized bits of the projection result of the selected angle delay pair.

[0228] In an optional implementation, the uplink measurement result includes the beam index of the uplink optimal beam between the second network device and the terminal device and the corresponding signal strength, signal quality or signal-to-noise ratio.

[0229] In an optional embodiment, the processing unit 410 is used to determine that the terminal device will be switched to the cell when the offset between the signal quality of the cell and the signal quality of the serving cell in the uplink measurement result is greater than a preset offset, or the signal quality of the serving cell is lower than a first threshold and the signal quality of the cell is higher than a second threshold, and / or when the channel correlation of the uplink and downlink measurements obtained based on the uplink measurement result and the downlink measurement result reported by the terminal device meets relevant conditions; or, the processing unit 410 is used to determine not to switch the terminal device to the cell when the offset between the signal quality of the cell and the signal quality of the serving cell in the uplink measurement result is less than or equal to a preset offset, or the signal quality of the serving cell is not lower than the first threshold, or the signal quality of the cell is not higher than the second threshold, and / or when the channel correlation of the uplink and downlink measurements obtained based on the uplink measurement result and the downlink measurement result reported by the terminal device does not meet relevant conditions.

[0230] In an optional embodiment, the communication unit 420 is used to send a first request indication to the second network device before receiving the configuration information of the uplink signal from the second network device, and the first request indication is used to request the second network device to allocate exclusive uplink signal configuration information to the terminal device; the communication unit 420 is also used to receive the configuration information of the uplink signal from the second network device.

[0231] In another optional embodiment, the communication unit 420 is also used to receive a downlink measurement result from the terminal device before receiving the configuration information of the uplink signal from the second network device, and the downlink measurement result is obtained by the terminal device by measuring the service cell and the neighboring cell based on the downlink measurement control information; the processing unit 410 is used to determine the cell to which the terminal device is allowed to switch and the second network device to which the cell belongs based on the downlink measurement result; the first network device sends a second request indication to the second network device, and the second request indication is used to request that the terminal device be switched to the cell.

[0232] In another optional embodiment, the communication unit 420 is also used to receive downlink measurement feedback information from the terminal device before receiving the configuration information of the uplink signal from the second network device, and the downlink measurement feedback information includes the downlink measurement results obtained by the terminal device based on the downlink measurement control information to measure the service cell and the neighboring cell, and information about the selected switching cell; the processing unit 410 is used to determine whether to allow the terminal device to be switched to the cell based on the downlink measurement results; the communication unit 420 is also used to, if the processing unit 410 determines that the terminal device is allowed to be switched to the cell, the first network device sends a second request indication to the second network device, and the second request indication is used to request that the terminal device be switched to the cell.

[0233] In another optional embodiment, the communication unit 420 is further used to send the first request indication and the second request indication mentioned above to the second network device to request that the terminal device be switched to the second network device and the configuration information of the uplink signal mentioned above.

[0234] When the communication device is used to implement the functions of the terminal device in the method embodiments shown in FIG. 4 to FIG. 6 :

[0235] The communication unit 420 is used to receive configuration information of an uplink signal from the first network device, where the configuration information is configuration information of an exclusive uplink signal assigned to the terminal device by the second network device, and the uplink measurement result of the uplink signal is used by the first network device to determine whether to switch the terminal device to the cell of the second network device; the communication unit 420 is also used to send the uplink signal according to the configuration information.

[0236] In an optional embodiment, the communication unit 420 is also used to receive a switching command message from the first network device after sending the exclusive uplink signal according to the configuration information, and the switching command message is used to instruct the terminal device to switch to the cell; the processing unit 410 is used to perform cell switching according to the switching command message, and the communication unit 420 is also used to send a switching confirmation message to the second network device.

[0237] In an optional embodiment, the switching command message includes uplink synchronization information and uplink resource allocation information. The uplink synchronization information is obtained by the second network device through uplink synchronization based on the received uplink signal. The uplink resource allocation information is used to indicate the uplink resources allocated by the second network device to the terminal device.

[0238] In an optional embodiment, the communication unit 420 is used to send a downlink measurement result to the first network device before receiving the configuration information of the uplink signal from the first network device. The downlink measurement result is obtained by the terminal device by measuring the service cell and the neighboring cell based on the downlink measurement control information, and is used by the first network device to determine the cell to which the terminal device is allowed to be switched and the second network device to which the cell belongs.

[0239] In another optional embodiment, the communication unit 420 is used to send downlink measurement feedback information to the first network device before receiving the configuration information of the uplink signal from the first network device, where the downlink measurement feedback information includes the downlink measurement result and information of the selected cell to be switched; the downlink measurement result is obtained by the terminal device by measuring the service cell and the neighboring cell based on the downlink measurement control information, and is used by the first network device to determine whether the terminal device is allowed to switch to the cell, and the network device to which the cell belongs is the second network device.

[0240] In an optional embodiment, the downlink measurement result includes the quantized bits of the amplitude and phase of the main eigenvector of the channel between the second network device and the terminal device, or includes the oversampling group index of the space-frequency projection matrix of the channel between the second network device and the terminal device, the index of the angle delay pair selected after space-frequency projection, and the quantized bits of the projection result of the selected angle delay pair.

[0241] A more detailed description of the processing unit 410 and the communication unit 420 can be directly obtained by referring to the relevant descriptions in the method embodiments shown in Figures 4 to 6, and will not be repeated here.

[0242] When the communication device is used to implement the function of the second network device in the method embodiments shown in FIG. 4 to FIG. 6 :

[0243] The communication unit 420 is configured to send uplink signal configuration information to the first network device; the configuration information is exclusive uplink signal configuration information allocated to the terminal device, and the uplink measurement result of the uplink signal is used by the first network device to determine whether to hand over the terminal device to the cell of the second network device;

[0244] The processing unit 410 is configured to perform measurement based on the received uplink signal to obtain an uplink measurement result, where the uplink signal is sent by the terminal device based on the configuration information;

[0245] The communication unit 420 is further configured to send the uplink measurement result to the first network device.

[0246] In an optional embodiment, the communication unit 420 is also used to send uplink synchronization information and uplink resource allocation information to the first network device, the uplink synchronization information is obtained based on uplink synchronization of the received uplink signal, and the uplink resource allocation information is used to indicate the uplink resources allocated to the terminal device.

[0247] In an optional embodiment, the uplink measurement result includes the quantized bits of the amplitude and phase of the main eigenvector of the channel between the second network device and the terminal device, or includes the oversampling group index of the space-frequency projection matrix of the channel between the second network device and the terminal device, the index of the angle delay pair selected after space-frequency projection, and the quantized bits of the projection result of the selected angle delay pair; and / or, the uplink measurement result includes the beam index of the uplink optimal beam between the second network device and the terminal device and the corresponding signal strength, signal quality or signal-to-noise ratio.

[0248] In an optional embodiment, the communication unit 420 is also used to receive a first request indication from the first network device before sending the configuration information of the uplink signal to the first network device, and the first request indication is used to request the second network device to allocate exclusive uplink signal configuration information to the terminal device.

[0249] In another optional embodiment, the communication unit 420 is also used to receive a second request indication from the first network device, which second request indication is used to request that the terminal device be switched to the cell; the processing unit 410 is used to trigger the communication unit 420 to execute the step of sending the configuration information of the uplink signal to the first network device when allowing the terminal device to be switched to the cell.

[0250] In another optional embodiment, the communication unit 420 is further used to receive the first request indication and the second request indication mentioned above from the first network device to request to switch the terminal device to the second network device and the configuration information of the uplink signal mentioned above.

[0251] A more detailed description of the processing unit 410 and the communication unit 420 can be directly obtained by referring to the relevant descriptions in the method embodiments shown in Figures 4 to 6, and will not be repeated here.

[0252] As shown in Figure 8, the communication device includes a processor 510 and an interface circuit 520. The processor 510 and the interface circuit 520 are coupled to each other. It is understood that the interface circuit 520 can be a transceiver or an input / output interface. Optionally, the communication device may further include a memory 530 for storing instructions executed by the processor 510, input data required by the processor 510 to execute instructions, or data generated after the processor 510 executes instructions.

[0253] When the communication device is used to implement any one of the methods shown in FIG. 4 to FIG. 6 , the processor 510 is used to implement the functions of the processing unit 410 , and the interface circuit 520 is used to implement the functions of the communication unit 420 .

[0254] When the communication device is a chip used in a terminal device, the chip implements the functions of the terminal device in the above method embodiments. The chip receives information from other modules in the terminal device (such as a radio frequency module or antenna), and the information is sent by the network device to the terminal device; or the chip sends information to other modules in the terminal device (such as a radio frequency module or antenna), and the information is sent by the terminal device to the network device.

[0255] When the above-mentioned communication device is a module applied to a network device, the module implements the functions of the network device in the above-mentioned method embodiment. The module receives information from other modules in the network device (such as a radio frequency module or an antenna), and the information is sent by the terminal device to the network device; or the module sends information to other modules in the network device (such as a radio frequency module or an antenna), and the information is sent by the network device to the terminal device. The module here can be a baseband chip of the network device, or a distributed unit (DU) or other module. The DU here can be a DU under the open radio access network (O-RAN) architecture.

[0256] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0257] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, a register, a hard disk, a mobile hard disk, a CD-ROM or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a base station or a terminal. Of course, the processor and the storage medium can also exist in a base station or a terminal as discrete components.

[0258] In the above embodiments, all or part of the embodiments may be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are performed in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, or other programmable device. The computer program or instructions may be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions may be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; an optical medium, such as a digital video disk; or a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or nonvolatile storage medium, or may include both volatile and nonvolatile types of storage media.

[0259] In the various embodiments of the present application, unless otherwise specified or there is any logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0260] It is understood that the various numbers used in the embodiments of this application are merely for ease of description and are not intended to limit the scope of the embodiments of this application. The order of the sequence numbers of the above-mentioned processes does not necessarily imply a specific order of execution; the order of execution of the processes should be determined by their functions and inherent logic.

Claims

1. A cell handover method, characterized in that: The method comprises: Receiving configuration information of an uplink signal from a second network device, where the configuration information is exclusive uplink signal configuration information allocated by the second network device to the terminal device; Sending the configuration information of the uplink signal to the terminal device; receiving an uplink measurement result from the second network device, where the uplink measurement result is obtained by the second network device through measurement based on a received uplink signal, and the uplink signal is sent by the terminal device based on the configuration information; Based on the uplink measurement result, determine whether to switch the terminal device to the cell of the second network device.

2. The method according to claim 1, characterized in that The method further comprises: If it is determined to switch the terminal device to the cell, a switching command message is sent to the terminal device, where the switching command message is used to instruct the terminal device to switch to the cell.

3. The method according to claim 2, characterized in that The method further comprises: receiving uplink synchronization information and uplink resource allocation information from the second network device, the uplink synchronization information being obtained by the second network device through uplink synchronization based on the received uplink signal, and the uplink resource allocation information being used to indicate uplink resources allocated by the second network device to the terminal device; The handover command message also includes the uplink synchronization information and the uplink resource allocation information.

4. The method according to any one of claims 1 to 3, characterized in that The uplink measurement result includes the quantized bits of the amplitude and phase of the main eigenvector of the channel between the second network device and the terminal device, or includes the oversampling group index of the space-frequency projection matrix of the channel between the second network device and the terminal device, the index of the angle delay pair selected after space-frequency projection, and the quantized bits of the projection result of the selected angle delay pair.

5. The method according to any one of claims 1 to 3, characterized in that The uplink measurement result includes the beam index of the uplink optimal beam between the second network device and the terminal device and the corresponding signal strength, signal quality or signal-to-noise ratio.

6. The method according to claim 4 or 5, characterized in that The determining, based on the uplink measurement result, whether to switch the terminal device to the cell includes: When the offset between the signal quality of the cell and the signal quality of the serving cell in the uplink measurement result is greater than a preset offset, or the signal quality of the serving cell is lower than a first threshold and the signal quality of the cell is higher than a second threshold, and / or when the channel correlation of the uplink and downlink measurements obtained based on the uplink measurement result and the downlink measurement result reported by the terminal device meets the relevant conditions, determining to switch the terminal device to the cell; or When the offset between the signal quality of the cell and the signal quality of the serving cell in the uplink measurement result is less than or equal to a preset offset, or the signal quality of the serving cell is not lower than a first threshold, or the signal quality of the cell is not higher than a second threshold, and / or when the channel correlation of the uplink and downlink measurements obtained based on the uplink measurement result and the downlink measurement result reported by the terminal device does not meet the relevant conditions, it is determined that the terminal device will not be switched to the cell.

7. The method according to any one of claims 1 to 6, characterized in that Before receiving the configuration information of the uplink signal from the second network device, the method further includes: A first request indication is sent to the second network device, where the first request indication is used to request the second network device to allocate exclusive uplink signal configuration information to the terminal device.

8. The method according to any one of claims 1 to 7, characterized in that Before receiving the configuration information of the uplink signal from the second network device, the method further includes: Receiving a downlink measurement result from the terminal device, where the downlink measurement result is obtained by the terminal device performing measurement of a serving cell and a neighboring cell based on downlink measurement control information; Determine, according to the downlink measurement result, a cell to which the terminal device is allowed to be switched and a second network device to which the cell belongs; A second request indication is sent to the second network device, where the second request indication is used to request that the terminal device be switched to the cell.

9. The method according to any one of claims 1 to 7, characterized in that Before receiving the configuration information of the uplink signal from the second network device, the method further includes: Receiving downlink measurement feedback information from the terminal device, the downlink measurement feedback information including downlink measurement results obtained by the terminal device by measuring the serving cell and the neighboring cell based on the downlink measurement control information, and information of the cell selected for switching; Determining whether to allow the terminal device to be handed over to the cell according to the downlink measurement result; If it is determined that the terminal device is allowed to be switched to the cell, a second request indication is sent to the second network device, where the second request indication is used to request that the terminal device be switched to the cell.

10. A cell switching method, characterized in that: The method comprises: receiving configuration information of an uplink signal from a first network device, where the configuration information is exclusive uplink signal configuration information allocated by a second network device to the terminal device, and an uplink measurement result of the uplink signal is used by the first network device to determine whether to hand over the terminal device to a cell of the second network device; The uplink signal is sent according to the configuration information.

11. The method according to claim 10, characterized in that The method further comprises: Receive a handover command message from the first network device, where the handover command is used to instruct the terminal device to switch to the cell; perform cell switching according to the handover command message, and send a handover confirmation message to the second network device.

12. The method according to claim 11, characterized in that The handover command message includes uplink synchronization information and uplink resource allocation information, The uplink synchronization information is obtained by the second network device through uplink synchronization based on the received uplink signal, and the uplink resource allocation information is used to indicate the uplink resources allocated by the second network device to the terminal device.

13. The method according to any one of claims 10 to 12, characterized in that Before receiving the configuration information of the uplink signal from the first network device, the method further includes: Send a downlink measurement result to the first network device, where the downlink measurement result is obtained by the terminal device by measuring the service cell and the neighboring cell based on the downlink measurement control information, and is used by the first network device to determine the cell to which the terminal device is to be switched and the second network device to which the cell belongs.

14. The method according to any one of claims 10 to 12, characterized in that Before receiving the configuration information of the uplink signal from the first network device, the method further includes: Sending downlink measurement feedback information to the first network device, where the downlink measurement feedback information includes a downlink measurement result and information about the selected handover cell; The downlink measurement result is obtained by the terminal device by measuring the serving cell and the neighboring cell based on the downlink measurement control information, and is used by the first network device to determine that the terminal device is allowed to switch to the cell, and the network device to which the cell belongs is the second network device.

15. The method according to claim 13 or 14, characterized in that The downlink measurement result includes the quantized bits of the amplitude and phase of the main eigenvector of the channel between the second network device and the terminal device, or includes the oversampling group index of the space-frequency projection matrix of the channel between the second network device and the terminal device, the index of the angle delay pair selected after space-frequency projection, and the quantized bits of the projection result of the selected angle delay pair.

16. A cell switching method, characterized in that: The method comprises: Sending configuration information of an uplink signal to the first network device; the configuration information is configuration information of an exclusive uplink signal allocated to the terminal device, and the uplink measurement result of the uplink signal is used by the first network device to determine whether to switch the terminal device to the cell of the second network device; Performing measurement based on the received uplink signal to obtain an uplink measurement result, where the uplink signal is sent by the terminal device based on the configuration information; Send the uplink measurement result to the first network device.

17. The method according to claim 16, characterized in that The method further comprises: Uplink synchronization information and uplink resource allocation information are sent to the first network device, the uplink synchronization information is obtained by performing uplink synchronization based on the received uplink signal, and the uplink resource allocation information is used to indicate the uplink resources allocated to the terminal device.

18. The method according to claim 16 or 17, characterized in that The uplink measurement result includes the quantized bits of the amplitude and phase of the main eigenvector of the channel between the second network device and the terminal device, or includes the oversampling group index of the space-frequency projection matrix of the channel between the second network device and the terminal device, the index of the angle delay pair selected after space-frequency projection, and the quantized bits of the projection result of the selected angle delay pair; and / or, The uplink measurement result includes the beam index of the uplink optimal beam between the second network device and the terminal device and the corresponding signal strength, signal quality or signal-to-noise ratio.

19. The method according to any one of claims 16 to 18, characterized in that Before sending the configuration information of the uplink signal to the first network device, the method further includes: A first request indication is received from a first network device, where the first request indication is used to request the second network device to allocate exclusive uplink signal configuration information to the terminal device.

20. The method according to any one of claims 16 to 19, characterized in that The method further comprises: receiving a second request indication from the first network device, where the second request indication is used to request that the terminal device be handed over to the cell; If the terminal device is allowed to be switched to the cell, the operation of sending the configuration information of the uplink signal to the first network device is performed.

21. A communication system, characterized in that: The communication system includes a first network device, a second network device and a terminal device, the first network device is used to execute the method according to any one of claims 1 to 9, the terminal device is used to execute the method according to any one of claims 10 to 15, and the second network device is used to execute the method according to any one of claims 16 to 20.

22. A communication device, characterized in that: The method comprises a module for executing the method according to any one of claims 1 to 9, or a module for executing the method according to any one of claims 10 to 15, or a module for executing the method according to any one of claims 16 to 20.

23. A communication device, characterized in that: The method comprises a processor and an interface circuit, wherein the interface circuit is used to receive signals from other communication devices outside the communication device and transmit them to the processor or send signals from the processor to other communication devices outside the communication device, and the processor is used to implement the method according to any one of claims 1 to 9 through a logic circuit or execute code instructions, or to implement the method according to any one of claims 10 to 15, or to implement the method according to any one of claims 16 to 20.

24. A computer-readable storage medium, characterized in that The storage medium stores a computer program or instruction. When the computer program or instruction is executed by the communication device, it implements the method according to any one of claims 1 to 9, or implements the method according to any one of claims 10 to 15, or implements the method according to any one of claims 16 to 20.

25. A communication device, characterized in that: The communication device includes a processor and a transceiver; The transceiver is used to communicate with other communication devices, and the processor is used to run a computer program so that the communication device implements the method according to any one of claims 1 to 9, or implements the method according to any one of claims 10 to 15, or implements the method according to any one of claims 16 to 20.

26. A communication device, characterized in that: The communication device includes a memory, a processor and a transceiver; The transceiver is used to receive signals or send signals, the memory is used to store instructions or computer programs, and the processor is used to execute the computer programs or instructions stored in the memory so that the communication device performs the method according to any one of claims 1 to 9, or implements the method according to any one of claims 10 to 15, or implements the method according to any one of claims 16 to 20.

27. A computer program product, characterized in that The method comprises computer instructions, which, when executed on a computer, cause the computer to execute the method according to any one of claims 1 to 9, or implement the method according to any one of claims 10 to 15, or implement the method according to any one of claims 16 to 20.

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