Cell selection method and related equipment

Abstract

The invention provides a cell selection method and related equipment, and relates to the technical field of communication. The method comprises the following steps: determining a first target cell from a candidate cell set; determining a first signal arrival time of the first target cell based on the measurement of the first target signal; determining the signal arrival time delay of the first target cell based on the first signal arrival time and the signal arrival time of a reference cell, the reference cell being a cell with the minimum measured signal arrival time in a candidate cell set; and if the signal arrival time delay of the first target cell is greater than the time delay threshold, not accessing the first target cell. According to the embodiment of the invention, the cell signal is measured, the signal arrival time delay is calculated, and the signal arrival time delay is compared with the time delay threshold to judge whether the to-be-accessed cell belongs to the ultra-far cell, so that the failure of the terminal equipment to access the cell due to the configuration of the ultra-far cell is avoided, and the network service experience of the terminal equipment is improved.

Description

Technical Field

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

[0002] In a mobile communication network, a terminal needs to perform a cell selection step during power-on initialization. After the terminal accesses the network, as the terminal moves, when the signal quality of other cells starts to be better than that of the current serving cell, the terminal needs to reselect a serving cell.

[0003] In existing technologies, cell selection is based on the cell's signal quality. Generally, a terminal will select the cell with better signal quality as its serving cell. However, due to the complexities of actual network deployment and environmental conditions, a neighboring cell with better signal quality may be an extremely distant cell. When a terminal attempts to connect to this extremely distant cell, certain configurations in the extremely distant cell, such as the Physical Random Access Channel (PRACH), may cause the terminal to fail to access the cell. Summary of the Invention

[0004] In order to solve the above problems, the present application provides a cell selection method and related devices, the purpose of which is to avoid the problem that a terminal cannot access a cell.

[0005] In order to achieve the above objectives, this application provides the following technical solutions:

[0006] In the first aspect, the present application provides a method for cell selection, which is applied to a terminal device, and the method includes: determining a first target cell from a set of candidate cells; determining a first signal arrival time of the first target cell based on a measurement of the first target signal; determining a signal arrival delay of the first target cell based on the first signal arrival time and the signal arrival time of a reference cell, wherein the reference cell is a cell in the set of candidate cells with the smallest measured signal arrival time; in response to the signal arrival delay of the first target cell being greater than a delay threshold, not accessing the first target cell.

[0007] Specifically, an embodiment of the present application provides a method for cell selection, so that before a terminal device accesses the first target cell, it determines the signal arrival delay of the first target cell by the first signal arrival time of the first target cell and the first signal arrival time of the reference cell; then, it determines whether the signal arrival delay of the first target cell is less than a preset delay threshold. When it is determined that the signal arrival delay of the first target cell is greater than the preset delay threshold, it indicates that the first target cell belongs to an ultra-distant cell, and the terminal device does not access the first target cell. It can be seen that the embodiment of the present application measures the cell signal and calculates the signal arrival delay, and compares the signal arrival delay with the delay threshold to determine whether the cell to be accessed belongs to an ultra-distant cell, thereby avoiding the terminal device from failing to access the cell due to the configuration of the ultra-distant cell, and improving the network service experience of the terminal device.

[0008] Furthermore, when the terminal device determines that the signal arrival delay of the first target cell is less than a preset delay threshold, that is, determines that the first target cell is not an ultra-distant cell, the terminal device can access the first target cell.

[0009] In a possible implementation, the first target signal in the embodiment of the present application may be a primary synchronization signal (PSS) or a secondary synchronization signal (SSS).

[0010] In a possible implementation, the method further includes: accessing the first target cell in response to a signal arrival delay of the first target cell being less than a delay threshold.

[0011] Specifically, when it is determined that the signal arrival delay of the first target cell is less than a preset delay threshold, it is indicated that the first target cell is not an ultra-distant cell, and the terminal device accesses the first target cell. This ensures that the cell accessed by the terminal device is less than or equal to the ultra-distant cell, avoiding failure of the terminal device to access the cell.

[0012] In one possible implementation, after responding to the signal arrival delay of the first target cell being greater than the delay threshold, the method further includes: determining a second target cell from the candidate cell set; determining the second signal arrival time of the second target cell based on measurement of the second target signal; determining the signal arrival delay of the second target cell based on the second signal arrival time and the signal arrival time of the reference cell; and accessing the second target cell in response to the signal arrival delay of the second target cell being less than the delay threshold.

[0013] Specifically, after determining that the first target cell is an ultra-distant cell and not performing access processing on it, the terminal device can further determine a second target cell from the candidate cell set and similarly determine whether the second target cell is an ultra-distant cell based on the signal arrival delay of the second target cell and a preset delay threshold. If the second target cell is not an ultra-distant cell, it will perform cell access processing. This ensures that the cell selected by the terminal device is not an ultra-distant cell, avoiding the terminal device's access failure due to accessing an ultra-distant cell.

[0014] In a possible implementation, the second target signal in the embodiment of the present application may be a primary synchronization signal (PSS) or a secondary synchronization signal (SSS).

[0015] In one possible implementation, the method further includes: detecting and obtaining multiple cells; and determining a set of candidate cells based on a reference signal receiving power (RSRP) of each of the multiple cells and a preset power threshold value; wherein the RSRP is determined based on measurement of a specific reference signal of the cell.

[0016] Specifically, the terminal device can determine the reference signal received power of each cell by measuring the specific reference signal of each cell, and determine the cell whose measured cell reference signal received power is greater than the preset power threshold value as the candidate cell set. Among them, the specific reference signal can be selected according to the actual network environment. For example, in the fourth generation mobile information system (4th Generation Mobile Communication Technology, 4G) network environment, the specific reference signal can use the cell-specific reference signal (Cell-specific Reference Signals, CRS), and in the new wireless (New Radio, NR) network environment, the specific reference signal can use the synchronization signal block (SynchronizationSignal / PBCH Block, SSB).

[0017] In a possible implementation manner, the method further includes: receiving a delay threshold sent by the reference cell based on a broadcast message.

[0018] Specifically, in the embodiment of the present application, the delay threshold can be configured by the broadcast message of the reference cell. The terminal device receives the delay threshold sent by the reference cell, which is used to subsequently compare and judge the signal arrival delay of the target cell to determine whether the target cell is an ultra-distant cell.

[0019] In a possible implementation, the method further includes: obtaining a signal arrival time of each cell in the candidate cell set; and determining a reference cell according to a minimum value of the signal arrival time of each cell.

[0020] Specifically, the terminal device obtains the signal arrival time of each cell based on the measurement of the target signal of each cell in the candidate cell set, and determines the cell corresponding to the minimum signal arrival time among the signal arrival times of each cell as the reference cell.

[0021] In an embodiment of the present application, the terminal device determines a reference cell from a set of candidate cells based on the signal arrival time of each cell. The reference cell is the cell with the smallest signal arrival time in the candidate cell set. That is, when the terminal device measures the target signal of each cell in the candidate cell set, it first receives the target signal of the reference cell, that is, the reference cell is the cell in the candidate cell set that is closest to the terminal device. The signal arrival delay determined based on the signal arrival time of the candidate cell and the signal arrival time of the target cell can reflect the distance between the target cell and the terminal device compared with the reference cell. The comparison of the signal arrival delay with the delay threshold can determine whether the target cell constitutes an ultra-distant cell of the terminal device.

[0022] In one possible implementation, determining the signal arrival delay of the first target cell based on the first signal arrival time and the signal arrival time of the reference cell includes:

[0023] The signal arrival delay of the first target cell is determined by:

[0024] ΔT j =T j -T0; where T j is the first signal arrival time, T0 is the signal arrival time of the reference cell, ΔT j is the signal arrival delay of the first target cell.

[0025] Specifically, when the terminal device measures and obtains the first signal arrival time of the first target cell and the signal arrival time of the reference cell, it can subtract the signal arrival time of the reference cell from the first signal arrival time to obtain the signal arrival delay of the first target cell.

[0026] A second aspect of the present application provides a cell selection method, which is applied to a network device, and includes: obtaining a signal arrival delay of each cell in a candidate cell set, and determining a signal arrival delay of a first target cell, wherein the first target cell is a cell in the candidate cell set, and the signal arrival delay of the first target cell is determined based on a first signal arrival time of the first target cell and a signal arrival time of a reference cell, the first signal arrival time is determined by a terminal device based on a measurement of a first target signal, and the reference cell is a cell in the candidate cell set with the smallest measured signal arrival time; in response to the signal arrival delay of the first target cell being greater than a delay threshold, not sending a first cell switching instruction to the terminal device, the first cell switching instruction being used to instruct the terminal device to access the first target cell.

[0027] Specifically, an embodiment of the present application provides a method for cell selection, in which a network device determines the signal arrival delay of a first target cell, and compares the signal arrival delay of the first target cell with a delay threshold value, and when the signal arrival delay of the first target cell is greater than the delay threshold value, determines that the first target cell belongs to an ultra-distant cell, and therefore does not send a first cell switching instruction to the terminal device, thereby preventing the terminal device from accessing the first target cell. It can be seen that the embodiment of the present application compares the signal arrival delay of the cell with the delay threshold value to determine whether the cell to be accessed belongs to an ultra-distant cell, and does not instruct the terminal device to access when it is determined that the cell to be accessed belongs to an ultra-distant cell, thereby avoiding the terminal device from failing to access the cell due to the configuration of the ultra-distant cell, thereby improving the network service experience of the terminal device.

[0028] Furthermore, when the network device determines that the signal arrival delay of the first target cell is less than a preset delay threshold, that is, determines that the first target cell is not an ultra-distant cell, the network device can instruct the terminal device to access the first target cell.

[0029] In a possible implementation, the method further includes: in response to a signal arrival delay of the first target cell being less than a delay threshold, sending a first cell switching instruction to the terminal device.

[0030] Specifically, the network device determines that the signal arrival delay of the first target cell is less than the delay threshold, determines that the first target cell is not an ultra-distant cell, and sends a first cell handover instruction to the terminal device, so that the terminal device accesses the first target cell. As can be seen, the embodiment of the present application instructs the terminal device to access the cell after determining that the cell to be accessed is not an ultra-distant cell, ensuring that the terminal device can successfully access the cell and improving the network service experience of the terminal device.

[0031] In a possible implementation, determining the signal arrival delay of the first target cell includes: receiving the signal arrival delay of the first target cell sent by a terminal device.

[0032] Specifically, the network device may receive the signal arrival delay of the first target cell sent by the terminal device, the terminal device measures and obtains corresponding time parameters, and reports the calculated signal arrival delay of the first target to the network device.

[0033] In a possible implementation, the terminal device determines the signal arrival delay of the first target cell in the following manner: Where, ΔT j is the signal arrival delay of the first target cell, min is the minimum operator, Indicates (T j –T0) / N step The result of the floor operation is rounded down, T j is the arrival time of the first signal, T0 is the arrival time of the signal of the reference cell, N step is the quantization step size, N max ΔT j The reporting upper limit value.

[0034] Specifically, since the network device instructs the terminal device to report the signal arrival delay of the first target cell, the terminal device needs to report the signal arrival delay data according to the unit requirements adapted by the network device. The terminal device first calculates the initial value of the signal arrival delay based on the first signal arrival time and the signal arrival time of the reference cell, then divides the initial value of the signal arrival delay by the preset quantization step size and rounds down to obtain the quantized value of the signal arrival delay. Finally, the quantized value of the signal arrival delay is compared with the preset upper limit value of the signal arrival delay report. If the quantized value of the signal arrival delay is less than the preset upper limit value of the signal arrival delay report, the quantized value of the signal arrival delay is used as the signal arrival delay of the target cell; if the quantized value of the signal arrival delay is greater than the preset upper limit value of the signal arrival delay report, the preset upper limit value of the signal arrival delay report is used as the signal arrival delay of the target cell. Among them, the upper limit value of the signal arrival delay report provides the upper limit value reported by the terminal device, and the minimum operator is used to ensure that the signal arrival delay calculated by the terminal device does not exceed the upper limit value of the report.

[0035] In one possible implementation, determining the signal arrival delay of the first target cell includes: receiving the first signal arrival time sent by the terminal device and the signal arrival time of the reference cell; and determining the signal arrival delay of the first target cell based on the first signal arrival time and the signal arrival time of the reference cell.

[0036] Specifically, the network device may receive the arrival time of the first signal sent by the terminal device and the arrival time of the signal of the reference cell, and the network device may calculate the signal arrival delay of the first target cell by itself.

[0037] In one possible implementation, determining the signal arrival delay of the first target cell based on the first signal arrival time and the signal arrival time of the reference cell includes:

[0038] The signal arrival delay of the first target cell is determined by:

[0039] ΔT j =T j -T0; where T j is the first signal arrival time, T0 is the signal arrival time of the reference cell, ΔT j is the signal arrival delay of the first target cell.

[0040] Specifically, the terminal device reports the first signal arrival time of the network device and the signal arrival time of the reference cell. The network device can subtract the signal arrival time of the reference cell from the first signal arrival time to obtain the signal arrival delay of the first target cell.

[0041] In one possible implementation, the method further includes: in response to the signal arrival delay of the first target cell being greater than a delay threshold, adding the first target cell to a blacklist cell list, the blacklist cell list being used to indicate that the measurement results of the first target cell are not reported and / or indicating that the first target cell is an inaccessible cell.

[0042] Specifically, the network device determines that the signal arrival delay of the first target cell is greater than the delay threshold, that is, it determines that the first target cell is an ultra-distant cell for the current terminal device, and therefore adds the first target cell to the blacklist cell list. Subsequently, other terminal devices can be informed through high-level messages not to report the measurement results of the first target cell, thereby avoiding other terminal devices from making unnecessary measurement reports, saving communication overhead, and / or informing other terminal devices that the first target cell is an inaccessible cell, thereby avoiding other cells from failing to access the ultra-distant cell due to cell access failure and affecting the network service experience. Among them, the high-level message can be a specific selection made by the network environment. For example, in the new wireless NR system, the high-level message can be the intraFreqBlackCellList information of the blacklisted frequency neighboring cell list in the third type of system information (System Information Block Type 3, SIB3) or the interFreqBlackCellList information of the blacklisted frequency neighboring cell list in the fourth type of system information (System Information Block Type 4, SIB4).

[0043] In one possible implementation, after determining that the signal arrival delay of the first target cell is greater than the delay threshold, that is, judging that the first target cell is an ultra-distant cell, the method further includes: determining the signal arrival delay of the second target cell, wherein the second target cell is a cell in the candidate cell set, and the signal arrival delay of the second target cell is determined based on the second signal arrival time of the second target cell and the signal arrival time of the reference cell, and the second signal arrival time is determined by the terminal device based on the measurement of the second target signal; in response to the signal arrival delay of the second target cell being less than the delay threshold, sending a second cell switching instruction to the terminal device, and the second cell switching instruction is used to instruct the terminal device to access the second target cell.

[0044] Specifically, after determining that the first target cell is an ultra-far cell for the terminal device, the network device further determines the signal arrival delay of the second target cell, and compares it with the delay threshold to determine whether the second target cell is an ultra-far cell. If the second target cell is not an ultra-far cell, a second cell switching instruction is sent to the terminal device, so that the terminal device accesses the second target cell. It can be seen that the embodiment of the present application compares the signal arrival delay of the cell with the delay threshold to determine whether the cell to be accessed is an ultra-far cell. When it is determined that the cell to be accessed is not an ultra-far cell, the terminal device is instructed to access the cell, thereby avoiding the terminal device from failing to access the cell due to the configuration of the ultra-far cell, thereby improving the network service experience of the terminal device.

[0045] In a possible implementation, the delay threshold is sent to the terminal device based on a broadcast message by a reference cell.

[0046] Specifically, in the embodiment of the present application, the delay threshold can be configured by the broadcast message of the reference cell. The terminal device receives the delay threshold sent by the reference cell, which is used to subsequently compare and judge the signal arrival delay of the target cell to determine whether the target cell is an ultra-distant cell.

[0047] A third aspect of the present application provides a terminal device, comprising:

[0048] a cell determination unit, configured to determine a first target cell from a set of candidate cells;

[0049] a signal measuring unit, configured to determine a first signal arrival time of a first target cell based on a measurement of the first target signal;

[0050] a delay measurement unit, configured to determine a signal arrival delay of a first target cell based on the first signal arrival time and the signal arrival time of a reference cell, wherein the reference cell is a cell in the set of candidate cells having the smallest measured signal arrival time;

[0051] The cell access unit is configured to not access the first target cell in response to a signal arrival delay of the first target cell being greater than a delay threshold.

[0052] A fourth aspect of the present application provides a network device, comprising:

[0053] a delay acquisition unit, configured to acquire a signal arrival delay of each cell in the candidate cell set, and determine the signal arrival delay of a first target cell, wherein the first target cell is a cell in the candidate cell set, and the signal arrival delay of the first target cell is determined based on a first signal arrival time of the first target cell and a signal arrival time of a reference cell, wherein the first signal arrival time is determined by a terminal device based on measurement of a first target signal, and the reference cell is a cell in the candidate cell set having the smallest measured signal arrival time;

[0054] An instruction sending unit is used to not send a first cell switching instruction to the terminal device in response to the signal arrival delay of the first target cell being greater than the delay threshold, where the first cell switching instruction is used to instruct the terminal device to access the first target cell.

[0055] In a fifth aspect, the present application provides a communication device, comprising a processor, wherein the processor is connected to a memory, the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the communication device implements any one of the implementation methods in the first aspect of the present application.

[0056] In a sixth aspect of the present application, a communication device is provided, comprising a processor, wherein the processor is connected to a memory, the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the communication device implements any one of the implementation methods in the second aspect of the present application.

[0057] In a seventh aspect, the present application provides a computer-readable storage medium for storing a computer program or instruction. When the computer program or instruction is executed by a processor, the method of any one of the implementation methods in the first aspect or the second aspect of the present application is implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 A schematic diagram of a cell selection scenario provided in an embodiment of the present application;

[0059] Figure 2 A schematic diagram of the system architecture of a communication system provided in an embodiment of the present application;

[0060] Figure 3 A flowchart of a cell selection method provided in an embodiment of the present application;

[0061] Figure 4 A schematic diagram of the signal arrival delay calculation principle provided in an embodiment of the present application;

[0062] Figure 5 A flowchart of another cell selection method provided in an embodiment of the present application;

[0063] Figure 6 A schematic diagram of the structure of a terminal device provided in an embodiment of the present application;

[0064] Figure 7 A schematic diagram of the structure of a network device provided in an embodiment of the present application;

[0065] Figure 8 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0066] Figure 9 A schematic structural diagram of another communication device provided in an embodiment of the present application;

[0067] Figure 10 A schematic diagram of the structure of a computer program product provided in an embodiment of the present application. DETAILED DESCRIPTION

[0068] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to be limiting of the present application. As used in the specification and appended claims of the present application, the singular expressions "one", "a kind of", "said", "above", "the" and "this" are intended to also include expressions such as "one or more", unless there is a clear contrary indication in the context. It should also be understood that in the embodiments of the present application, "one or more" refers to one, two or more; "and / or" describes the association relationship of associated objects, indicating that three relationships may exist; for example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship.

[0069] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in yet other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0070] The "multiple" involved in the embodiments of the present application means greater than or equal to two. It should be noted that in the description of the embodiments of the present application, the words "first" and "second" are only used for the purpose of distinguishing the description and cannot be understood as indicating or implying relative importance or order.

[0071] As described in the background technology, in a mobile communication network, a terminal needs to perform a cell selection step during the power-on initialization process. After the terminal is connected to the network, as the terminal moves, when the signal quality of other cells begins to be better than the signal quality of the current service cell, the terminal needs to reselect the service cell.

[0072] like Figure 1 The diagram shows a cell selection scenario in which a user equipment (UE) is at the coverage edge of serving cell Cell#2 and gradually moves away from Cell#2. Due to certain network deployment reasons (e.g., the signal transmission power of Cell#1 is higher than that of Cell#2 and other nearby cells, or the antennas of Cell#2 and other nearby cells are deployed at a lower height, causing the signal to be blocked by buildings around the UE, while the antenna of Cell#1 is deployed at a higher height, allowing its signal to avoid being blocked by buildings around the UE), the UE will find that Cell#1 has better signal quality and will select Cell#1 as the new serving cell.

[0073] However, the neighboring cell Cell#1 with better signal quality may be an ultra-distant cell, which means that although the UE can receive the signal of the cell, certain configurations of the cell (eg, PRACH configuration) may prevent the UE from accessing the cell.

[0074] According to the New Radio (NR) or Long Term Evolution (LTE) protocol, the preamble is constructed from a cyclically shifted ZC sequence:

[0075] x u,v (n) = x u ((n+C v )mod L RA )

[0076]

[0077] Among them, L RA is the length of the preamble sequence, u is the physical root index of the sequence, C v is the vth cyclic shift amount.

[0078] C v =v·N CS , Among them, N CS It is the unit cyclic shift amount and is configured by higher layers.

[0079] In a cell, there are 64 preambles for the UE to select to initiate random access. The 64 preambles are determined by starting from the initial logical root index configured by the higher layer, and for each ZC sequence corresponding to the logical root index, each cyclic shift (C v ) is recorded as 1 preamble. When the maximum cyclic shift is reached, the ZC sequence corresponding to the next logical root index is determined, and each cyclic shift (C v ) is recorded as 1 preamble, and so on, until 64 preambles are determined.

[0080] From the perspective of the physical random access channel PRACH, N Cs Determines the coverage distance of PRACH. When a UE sends a preamble to a cell from a location beyond the PRACH coverage distance, the cell will mistake the preamble for another preamble. For example, if the preamble sequence sent by the UE is:

[0081] x u,v (n) = x u ((n+C v )mod L RA )

[0082] The preamble signal received by the base station is:

[0083]

[0084] Where d is the distance between the UE and the base station, c is the speed of light, and μ is the subcarrier spacing of the PRACH.

[0085] Obviously, if The base station will then misidentify the preamble sent by the UE. The base station will then send the misidentified preamble index to the UE in a random access response message. If the UE does not receive any random access response message containing the preamble index it sent for a period of time, it will resend the preamble. It is foreseeable that in this case, even if the preamble is resent, the UE will not receive a random access response message containing the preamble index it sent from the base station until the maximum number of preamble transmissions is reached, and the UE's random access will fail.

[0086] In order to avoid the problem that a terminal device cannot access a cell due to being connected to an ultra-distant cell, an embodiment of the present application provides a cell selection method that can be applied to a communication system for synchronous deployment, that is, the wireless frame transmission time of each cell in the network is synchronized. In the embodiment of the present application, the communication system can be a second-generation (2G) communication system, a third-generation (3G) communication system, an LTE system, a fifth-generation (5G) communication system, a hybrid architecture of LTE and 5G, a 5G New Radio (5G NR) system, and new communication systems that will emerge in future communication developments, such as a 6G system.

[0087] The communication system includes a first device and a second device. The first device can be a device on the network side for providing network communication functions, which is sometimes also called a network device or a network element. The network device can generally be a base station (including a functional unit of a base station, or a combination of functional units of a base station) or a core network unit, wherein the core network unit can be a functional unit in the core network, including but not limited to an access and mobility management function (AMF) unit or a session management function (SMF) unit. The second device can be a device for accessing the network, which can generally be a terminal. An example of a communication system is as follows: Figure 2 As shown, Figure 2 It includes base station 1 and terminal 2.

[0088] In the embodiments provided in the present application, the base station can be any device with wireless transceiver functions, including but not limited to: an evolved base station (NodeB or eNB or e-NodeB, evolutionary NodeB) in long term evolution (LTE), a base station (gNodeB or gNB) or a transmission receiving point (TRP) in new radio (NR), a base station of subsequent evolution of 3GPP, an access node in a Wi-Fi system, a wireless relay node, a wireless backhaul node, etc. The base station can be: a macro base station, a micro base station, a pico base station, a small station, a relay station, or a balloon station, etc. The base station can include one or more co-sited or non-co-sited transmission points (Transmission Reception Point, TRP). The base station can also be a wireless controller, a centralized unit (CU), and / or a distributed unit (DU) in a cloud radio access network (CRAN) scenario. The base station can communicate with the terminal, or communicate with the terminal through a relay station. The terminal can communicate with multiple base stations of different technologies. For example, the terminal can communicate with a base station supporting the LTE network, and can also communicate with a base station supporting the 5G network. It can also establish dual connections with a base station supporting the LTE network and a base station supporting the 5G network.

[0089] In the embodiments provided herein, the terminal may be in various forms, such as a mobile phone, a tablet computer, a computer with wireless transceiver function, 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, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, a wearable terminal device, etc. The terminal may also be sometimes referred to as a terminal device, user equipment (UE), access terminal device, vehicle-mounted terminal, industrial control terminal, UE unit, UE station, mobile station, mobile station, remote station, remote terminal device, mobile device, UE terminal device, terminal device, wireless communication device, UE agent or UE device, etc. The terminal may also be a fixed terminal or a mobile terminal.

[0090] In order to make the technical solution of the present application clearer and easier to understand, the cell selection method provided in the embodiment of the present application is introduced below with reference to the accompanying drawings.

[0091] See also Figure 3 A flowchart of a cell selection method is shown, which is applied to a terminal device and includes:

[0092] Step S101: Determine a first target cell from a set of candidate cells.

[0093] Specifically, the terminal device may determine the first target cell from the set of candidate cells based on factors such as the signal quality or frequency priority of the cell. The embodiment of the present application does not limit the method of selecting the first target cell. For example, the terminal device may determine the first target cell from the set of candidate cells based on signal quality. The terminal device may also determine the first target cell from the set of candidate cells based on frequency priority. The terminal device may also determine the first target cell from the set of candidate cells based on signal quality and frequency priority. Those skilled in the art can adjust the method of selecting the target cell based on actual conditions.

[0094] The candidate cell set may be a set where the terminal device determines the reference signal received power RSRP of each cell based on the measurement of the specific reference signal of each cell, and determines the cells whose measured RSRP is greater than a preset power threshold value as the candidate cell set.

[0095] It should be noted that the specific reference signal can be selected based on the actual network environment. For example, in the 4th Generation Mobile Communication Technology (4G) network environment, the specific reference signal can be selected as the cell-specific reference signal (CRS), and in the new radio (NR) network environment, the specific reference signal can be selected as the synchronization signal block (SSB).

[0096] Step S102: Determine a first signal arrival time of a first target cell based on measurement of a first target signal.

[0097] Specifically, the first target signal can be a primary synchronization signal (PSS) or a secondary synchronization signal (SSS), and the terminal device determines the PSS signal arrival time or the SSS signal arrival time based on the measurement of the PSS or SSS. It can be understood that the signal arrival time refers to the moment when the terminal device receives the target signal sent by the target cell.

[0098] Step S103: Determine the signal arrival delay of the first target cell based on the first signal arrival time and the signal arrival time of the reference cell, where the reference cell is the cell with the smallest measured signal arrival time in the candidate cell set.

[0099] Specifically, the signal arrival time of the reference cell refers to the time when the terminal device receives the target signal sent by the reference cell, and the reference cell is the cell with the smallest signal arrival time measured among the cells in the candidate cell set, that is, the terminal device measures the signal arrival times of each cell in the candidate cell set and takes the cell corresponding to the target signal received first as the reference cell.

[0100] It should be noted that the target signal sent by the reference cell may also be the primary synchronization signal PSS or the secondary synchronization signal SSS.

[0101] See also Figure 4 The following is a schematic diagram showing a signal arrival delay calculation principle. Specifically, the terminal device can determine the signal arrival delay of the first target cell based on the following method:

[0102] At time T, the network side reference cell sends the target signal #m, and the first target cell sends the first target signal #n; at time T0, the terminal device measures the target signal #m; at time T j At this moment, the terminal device measures the first target signal #n; thus, the signal arrival delay ΔT of the first target cell j =T j -T0; where T j is the first signal arrival time, and T0 is the signal arrival time of the reference cell.

[0103] Step S104: In response to the signal arrival delay of the first target cell being greater than the delay threshold, the first target cell is not accessed.

[0104] Specifically, the terminal device compares the signal arrival delay of the first target cell with the delay threshold. If the signal arrival delay of the first target cell is greater than the delay threshold, it can be determined that the first target cell belongs to an ultra-distant cell, so the terminal device does not access the first target cell.

[0105] It can be seen that the embodiment of the present application measures the cell signal and calculates the signal arrival delay, and compares the signal arrival delay with the delay threshold to determine whether the cell to be accessed is an ultra-distant cell, thereby avoiding the terminal device from failing to access the cell due to the configuration of the ultra-distant cell, and improving the network service experience of the terminal device.

[0106] It should be noted that the embodiments of the present application do not limit the situation where the signal arrival delay of the first target cell is equal to the delay threshold. Those skilled in the art can make corresponding settings based on actual conditions. For example, the terminal device can access the first target cell when the signal arrival delay of the first target cell is equal to the delay threshold, or not access the first target cell.

[0107] In an optional implementation, a cell selection method provided by an embodiment of the present application further includes: accessing the first target cell in response to a signal arrival delay of the first target cell being less than a delay threshold.

[0108] Specifically, if it is determined that the signal arrival delay of the first target cell is less than a preset delay threshold, the first target cell is determined not to be an ultra-distant cell, and the terminal device can access the first target cell. This ensures that the target cell accessed by the terminal device is not an ultra-distant cell, ensuring that the terminal can successfully access the cell.

[0109] In an optional implementation, after determining that the first target cell belongs to an ultra-distant cell, the method further includes: determining a second target cell from a set of candidate cells; determining a second signal arrival time of the second target cell based on measurement of the second target signal; determining a signal arrival delay of the second target cell based on the second signal arrival time and the signal arrival time of the reference cell; and in response to the signal arrival delay of the second target cell being less than a delay threshold, accessing the second target cell.

[0110] Specifically, after the terminal device determines that the first target cell is an ultra-distant cell and does not access it, the terminal device further determines a second target cell from the candidate cell set and similarly determines whether the second target cell is an ultra-distant cell based on the signal arrival delay of the second target cell and a preset delay threshold. If the second target cell is not an ultra-distant cell, the terminal device performs cell access processing. This ensures that the cell selected by the terminal device is not an ultra-distant cell, avoiding the terminal device's access failure due to accessing an ultra-distant cell.

[0111] It should be noted that the terminal device can determine the second target cell from the candidate cell set based on factors such as the cell's signal quality or frequency priority. The embodiment of the present application does not limit the method of selecting the second target cell. Those skilled in the art can adjust the method of selecting the target cell based on actual conditions.

[0112] In an optional implementation manner, the signal quality of the first target cell is better than the signal quality of the second target cell, or the frequency priority of the first target cell is higher than the frequency priority of the second target cell.

[0113] It can be understood that when acquiring the target cell, the terminal device gives priority to selecting the first target cell from the candidate cells based on factors such as cell signal quality or cell frequency priority, and gives priority to selecting the second target cell from the candidate cells when the first target cell is an ultra-distant cell. Therefore, the target cell selected in the first round is superior to the target cell selected in the second round in terms of factors such as signal quality or cell frequency priority.

[0114] In an optional implementation, a cell selection method provided in an embodiment of the present application further includes: obtaining a signal arrival time of each cell in a candidate cell set; and determining a reference cell according to a minimum value of the signal arrival time of each cell.

[0115] Specifically, the terminal device obtains the signal arrival time of each cell based on the measurement of the target signal of each cell in the candidate cell set, and determines the cell corresponding to the minimum signal arrival time among the signal arrival times of each cell as the reference cell.

[0116] In an embodiment of the present application, the terminal device determines a reference cell from a set of candidate cells based on the signal arrival time of each cell. The reference cell is the cell with the smallest signal arrival time in the candidate cell set. That is, when the terminal device measures the target signal of each cell in the candidate cell set, it first receives the target signal of the reference cell, that is, the reference cell is the cell in the candidate cell set that is closest to the terminal device. The signal arrival delay determined based on the signal arrival time of the candidate cell and the signal arrival time of the target cell can reflect the distance between the target cell and the terminal device compared with the reference cell. The comparison of the signal arrival delay with the delay threshold can determine whether the target cell constitutes an ultra-distant cell of the terminal device.

[0117] In an optional implementation manner, a cell selection method provided by an embodiment of the present application further includes: receiving a delay threshold sent by a reference cell based on a broadcast message.

[0118] Specifically, the delay threshold can be configured by the broadcast message of the reference cell. The terminal device receives the delay threshold sent by the reference cell, which is used to subsequently compare and judge the signal arrival delay of the target cell to determine whether the target cell is an ultra-distant cell.

[0119] See below Figure 5 A flowchart of another cell selection method is shown, which is applied to a network device. The method includes:

[0120] Step S201: Obtain the signal arrival delay of each cell in the candidate cell set, and determine the signal arrival delay of the first target cell, where the first target cell is a cell in the candidate cell set, and the signal arrival delay of the first target cell is determined based on the first signal arrival time of the first target cell and the signal arrival time of the reference cell, where the first signal arrival time is determined by the terminal device based on measurement of the first target signal, and the reference cell is the cell in the candidate cell set with the smallest measured signal arrival time;

[0121] Step S202: In response to the signal arrival delay of the first target cell being greater than the delay threshold, a first cell switching instruction is not sent to the terminal device, where the first cell switching instruction is used to instruct the terminal device to access the first target cell.

[0122] Specifically, the network device first obtains the signal arrival delay of each cell in the candidate cell set, then determines the signal arrival delay of the first target cell, and compares the signal arrival delay of the first target cell with the delay threshold. When the signal arrival delay of the first target cell is greater than the delay threshold, it is determined that the first target cell belongs to an ultra-distant cell, and the first cell switching instruction is not sent to the terminal device, so as to avoid the terminal device from failing to access the cell due to accessing the first target cell belonging to an ultra-distant cell, thereby affecting the network service experience. It can be seen that the network device of the embodiment of the present application compares the signal arrival delay of the cell with the delay threshold to determine whether the cell to be accessed belongs to an ultra-distant cell. When it is determined that the cell to be accessed belongs to an ultra-distant cell, the terminal device is not instructed to access, thereby avoiding the terminal device from failing to access the cell due to the configuration of the ultra-distant cell, thereby improving the network service experience of the terminal device.

[0123] It should be noted that the embodiments of the present application do not limit the situation where the signal arrival delay of the first target cell is equal to the delay threshold. Those skilled in the art can make corresponding settings according to actual conditions. For example, the network device can send a first cell switching instruction to the terminal device when the signal arrival delay of the first target cell is equal to the delay threshold to instruct the terminal device to access the first target cell, or not send the first cell switching instruction, that is, not instruct the terminal device to access the first target cell.

[0124] In an optional implementation, a cell selection method provided by an embodiment of the present application further includes: in response to the signal arrival delay of the first target cell being less than a delay threshold, sending the first cell switching instruction to the terminal device.

[0125] Specifically, when the signal arrival delay in the first target cell is less than the delay threshold, it is determined that the first target cell does not belong to an ultra-distant cell, and a first cell switching instruction is sent to the terminal device, instructing the terminal device to access the first target cell, thereby ensuring that the terminal device will not cause cell access failure due to accessing an ultra-distant cell, affecting the network service experience.

[0126] In an optional implementation, determining the signal arrival delay of the first target cell in step S201 includes: receiving the signal arrival delay of the first target cell sent by the terminal device.

[0127] Specifically, the network device may receive the signal arrival delay of the first target cell sent by the terminal device, the terminal device measures and obtains corresponding time parameters, and reports the calculated signal arrival delay of the first target to the network device.

[0128] In a possible implementation, the terminal device determines the signal arrival delay of the first target cell in the following manner: Where, ΔT jis the signal arrival delay of the first target cell, min is the minimum operator, Indicates (T j –T0) / N step The result is rounded down, T j is the arrival time of the first signal, T0 is the arrival time of the signal of the reference cell, N step is the quantization step size, N max ΔT j The reporting upper limit value.

[0129] Specifically, since the network device instructs the terminal device to report the signal arrival delay of the first target cell, the terminal device needs to report the signal arrival delay data according to the unit requirements adapted by the network device. The terminal device first calculates the initial value of the signal arrival delay based on the first signal arrival time and the signal arrival time of the reference cell, then divides the initial value of the signal arrival delay by the preset quantization step size and rounds down to obtain the quantized value of the signal arrival delay, and finally compares the quantized value of the signal arrival delay with the preset reporting upper limit of the signal arrival delay. If the quantized value of the signal arrival delay is less than the preset reporting upper limit of the signal arrival delay, the quantized value of the signal arrival delay is used as the signal arrival delay of the target cell; if the quantized value of the signal arrival delay is greater than the preset reporting upper limit of the signal arrival delay, the preset reporting upper limit of the signal arrival delay is used as the signal arrival delay of the target cell. Among them, the reporting upper limit of the signal arrival delay provides the upper limit of the terminal device's reporting, which is determined by the number of bits reported by the terminal device. The minimum operator is used to ensure that the signal arrival delay calculated by the terminal device does not exceed the reporting upper limit.

[0130] It should be noted that the quantization step size N step and ΔT j The reporting upper limit N max It can be a fixed value preset in the network device or configured on the network side.

[0131] It can be understood that the signal arrival delay of the first target cell obtained by the terminal device through the above calculation is a quantified signal arrival delay, which can adapt to the unit requirements of the reception of the network device.

[0132] In one possible implementation, determining the signal arrival delay of the first target cell includes: receiving the first signal arrival time sent by the terminal device and the signal arrival time of the reference cell; and determining the signal arrival delay of the first target cell based on the first signal arrival time and the signal arrival time of the reference cell.

[0133] Specifically, the network device may receive the arrival time of the first signal sent by the terminal device and the arrival time of the signal of the reference cell, and the network device may calculate the signal arrival delay of the first target cell by itself.

[0134] In one possible implementation, determining the signal arrival delay of the first target cell based on the first signal arrival time and the signal arrival time of the reference cell includes:

[0135] The signal arrival delay of the first target cell is determined by:

[0136] ΔT j =T j -T0; where T j is the first signal arrival time, T0 is the signal arrival time of the reference cell, ΔT j is the signal arrival delay of the first target cell.

[0137] Specifically, the terminal device reports the first signal arrival time of the network device and the signal arrival time of the reference cell. The network device can subtract the signal arrival time of the reference cell from the first signal arrival time to obtain the signal arrival delay of the first target cell.

[0138] In one possible implementation, in response to the signal arrival delay of the first target cell being greater than the delay threshold, a cell selection method provided in an embodiment of the present application further includes: adding the first target cell to a blacklist cell list, the blacklist cell list being used to indicate that the measurement results of the first target cell are not reported and / or indicating that the first target cell is an inaccessible cell.

[0139] Specifically, the network device determines that the signal arrival delay of the first target cell is greater than the delay threshold, that is, it determines that the first target cell is an ultra-distant cell for the current terminal device, and therefore adds the first target cell to the blacklist cell list. Subsequently, it can inform other terminal devices through high-level messages not to report the measurement results of the first target cell, so as to avoid other terminal devices from making unnecessary measurement reports, saving communication overhead, and / or informing other terminal devices that the first target cell is an inaccessible cell, so as to avoid other cells from failing to access the ultra-distant cell due to cell access failure and affecting the network service experience. Among them, the high-level message can be a specific selection made by the network environment.

[0140] For example, in the new wireless NR system, the high-layer message can be the intraFreqBlackCellList information of the blacklisted frequency neighbor list in the third type of system information (SystemInformation Block Type 3, SIB3) or the interFreqBlackCellList information of the blacklisted frequency neighbor list in the fourth type of system information (SystemInformation Block Type 4, SIB4).

[0141] In one possible implementation, after responding to the signal arrival delay of the first target cell being greater than the delay threshold, a cell selection method provided by an embodiment of the present application further includes: determining the signal arrival delay of the second target cell, wherein the second target cell is a cell in the candidate cell set, and the signal arrival delay of the second target cell is determined based on the second signal arrival time of the second target cell and the signal arrival time of the reference cell, and the second signal arrival time is determined by the terminal device based on the measurement of the second target signal; in response to the signal arrival delay of the second target cell being less than the delay threshold, sending a second cell switching instruction to the terminal device, and the second cell switching instruction is used to instruct the terminal device to access the second target cell.

[0142] Specifically, after determining that the first target cell is an ultra-far cell for the terminal device, the network device further determines the signal arrival delay of the second target cell, and compares it with the delay threshold to determine whether the second target cell is an ultra-far cell. If the second target cell does not belong to an ultra-far cell, a second cell switching instruction is sent to the terminal device, so that the terminal device accesses the second target cell.

[0143] It can be seen that the embodiment of the present application compares the signal arrival delay of the cell with the delay threshold to determine whether the cell to be accessed is an ultra-far cell. When it is determined that the cell to be accessed does not belong to an ultra-far cell, it instructs the terminal device to access, thereby avoiding the terminal device's failure to access the cell due to the configuration of the ultra-far cell, and improving the network service experience of the terminal device.

[0144] In a possible implementation, the delay threshold is sent to the terminal device based on a broadcast message by a reference cell.

[0145] Specifically, in the embodiment of the present application, the delay threshold can be configured by the broadcast message of the reference cell. The terminal device receives the delay threshold sent by the reference cell, which is used to subsequently compare and judge the signal arrival delay of the target cell to determine whether the target cell is an ultra-distant cell.

[0146] See also Figure 6 The terminal device shown is a schematic structural diagram of a terminal device, the terminal device includes:

[0147] The cell determination unit 601 is configured to determine a first target cell from a set of candidate cells;

[0148] a signal measurement unit 602, configured to determine a first signal arrival time of a first target cell based on measurement of the first target signal;

[0149] a delay measurement unit 603 configured to determine a signal arrival delay of a first target cell based on the first signal arrival time and the signal arrival time of a reference cell, where the reference cell is a cell in the candidate cell set having the smallest measured signal arrival time;

[0150] The cell access unit 604 is configured to not access the first target cell in response to a signal arrival delay of the first target cell being greater than a delay threshold.

[0151] Specifically, an embodiment of the present application provides a terminal device, which measures the cell signal and calculates the signal arrival delay, and compares the signal arrival delay with the delay threshold to determine whether the cell to be accessed is an ultra-distant cell, thereby avoiding the terminal device's failure to access the cell due to the configuration of the ultra-distant cell, and improving the network service experience of the terminal device.

[0152] In a possible implementation, the cell access unit 604 is further configured to access the first target cell in response to a signal arrival delay of the first target cell being less than a delay threshold.

[0153] In a possible implementation, the cell determining unit 601 is further configured to determine a second target cell from the candidate cell set after determining that the signal arrival delay of the first target cell is greater than the delay threshold;

[0154] The signal measurement unit 602 is further configured to determine a second signal arrival time of the second target cell based on the measurement of the second target signal;

[0155] The delay measurement unit 603 is further configured to determine the signal arrival delay of the second target cell based on the second signal arrival time and the signal arrival time of the reference cell;

[0156] The cell access unit 604 is further configured to access the second target cell in response to a signal arrival delay of the second target cell being less than a delay threshold.

[0157] In a possible implementation, the terminal device further includes:

[0158] A cell detection unit, used to detect and obtain multiple cells;

[0159] The cell determination unit is configured to determine a candidate cell set based on a reference signal received power (RSRP) of each cell in a plurality of cells and a preset power threshold value; wherein RSRP is determined based on measurement of a specific reference signal of the cell.

[0160] In a possible implementation, the terminal device further includes:

[0161] The threshold receiving unit is configured to receive a delay threshold sent by the reference cell based on a broadcast message.

[0162] In one possible implementation,

[0163] The signal measurement unit 602 is further configured to obtain a signal arrival time of each cell in the candidate cell set;

[0164] The cell determining unit 601 is further configured to determine a reference cell according to a minimum value of the signal arrival times of each cell.

[0165] In a possible implementation, the delay measurement unit 603 is specifically configured to determine the signal arrival delay of the first target cell by:

[0166] ΔT j =T j -T0; where T j is the first signal arrival time, T0 is the signal arrival time of the reference cell, ΔT j is the signal arrival delay of the first target cell.

[0167] It should be noted that the steps executed by each unit in a network device provided in an embodiment of the present application and the related technical features correspond to the method for cell selection applied to a terminal device provided in the aforementioned embodiment of the application. The description of the device part can be found in the embodiment of the aforementioned method part and will not be repeated here.

[0168] See also Figure 7 A schematic diagram of the structure of a network device is shown, the network device includes:

[0169] a delay acquisition unit 701, configured to acquire a signal arrival delay of each cell in the candidate cell set, and determine a signal arrival delay of a first target cell, where the first target cell is a cell in the candidate cell set, and the signal arrival delay of the first target cell is determined based on a first signal arrival time of the first target cell and a signal arrival time of a reference cell, where the first signal arrival time is determined by a terminal device based on measurement of a first target signal, and the reference cell is a cell in the candidate cell set having the smallest measured signal arrival time;

[0170] The instruction sending unit 702 is used to not send a first cell switching instruction to the terminal device in response to the signal arrival delay of the first target cell being greater than the delay threshold, where the first cell switching instruction is used to instruct the terminal device to access the first target cell.

[0171] Specifically, an embodiment of the present application provides a network device, which compares the signal arrival delay of the cell with the delay threshold to determine whether the cell to be accessed is an ultra-far cell. When it is determined that the cell to be accessed is an ultra-far cell, the terminal device is not instructed to access, thereby avoiding the terminal device's failure to access the cell due to the configuration of the ultra-far cell, thereby improving the network service experience of the terminal device.

[0172] In a possible implementation, the instruction sending unit 702 is further configured to send a first cell switching instruction to the terminal device in response to a signal arrival delay of the first target cell being less than a delay threshold.

[0173] Specifically, the network device determines that the signal arrival delay of the first target cell is less than the delay threshold, determines that the first target cell is not an ultra-distant cell, and sends a first cell handover instruction to the terminal device, so that the terminal device accesses the first target cell. As can be seen, the embodiment of the present application instructs the terminal device to access the cell after determining that the cell to be accessed is not an ultra-distant cell, ensuring that the terminal device can successfully access the cell and improving the network service experience of the terminal device.

[0174] In a possible implementation, the delay acquisition unit 701 is specifically configured to receive a signal arrival delay of a first target cell sent by a terminal device.

[0175] In a possible implementation, the terminal device determines the signal arrival delay of the first target cell in the following manner: Where, ΔT j is the signal arrival delay of the first target cell, min is the minimum operator, Indicates (T j –T0) / N step Perform floor operation, T j is the arrival time of the first signal, T0 is the arrival time of the signal of the reference cell, N step is the quantization step size, N max ΔT j The reporting upper limit value.

[0176] In a possible implementation, the delay acquisition unit 701 includes:

[0177] A time receiving subunit, configured to receive a first signal arrival time sent by a terminal device and a signal arrival time of a reference cell;

[0178] The delay determination subunit is configured to determine the signal arrival delay of the first target cell based on the first signal arrival time and the signal arrival time of the reference cell.

[0179] In a possible implementation, the network device further includes:

[0180] A blacklist adding unit is used to add the first target cell to a blacklist cell list in response to the signal arrival delay of the first target cell being greater than the delay threshold, wherein the blacklist cell list is used to indicate that the measurement result of the first target cell is not reported and / or to indicate that the first target cell is an inaccessible cell.

[0181] In one possible implementation, the delay acquisition unit 701 is further configured to, in response to the signal arrival delay of the first target cell being greater than the delay threshold, determine a signal arrival delay of a second target cell, where the second target cell is a cell in the candidate cell set, and the signal arrival delay of the second target cell is determined based on a second signal arrival time of the second target cell and a signal arrival time of the reference cell, where the second signal arrival time is determined by the terminal device based on measurement of the second target signal;

[0182] The instruction sending unit 702 is further used to send a second cell switching instruction to the terminal device in response to the signal arrival delay of the second target cell being less than the delay threshold, where the second cell switching instruction is used to instruct the terminal device to access the second target cell.

[0183] It should be noted that the steps performed by each unit in a network device provided in an embodiment of the present application and the related technical features correspond to the method for cell selection applied to a network device provided in the aforementioned embodiment of the application. The description of the device part can be found in the embodiment of the aforementioned method part and will not be repeated here.

[0184] An embodiment of the present application also provides a communication device, which may specifically be a network device or a terminal device in the aforementioned embodiment. The communication device includes a processor, which is connected to a memory. The memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the communication device implements any one of the cell selection methods provided in the aforementioned embodiments.

[0185] Figure 8 A schematic diagram of the structure of a communication device provided in an embodiment of the present application. The communication device may be a first device, including but not limited to a base station and a core network unit. Figure 8A simplified schematic diagram of the base station structure is shown. The base station 800 includes a processor 810 part, a memory 820 part, and a transceiver 830 part. The processor 810 part is mainly used for baseband processing, controlling the base station, etc.; the processor 810 part is usually the control center of the base station, which can usually be called a processor, and is used to control the base station to perform the processing operations on the first device side in the above method embodiment. The memory 820 part is mainly used to store computer program code and data. The transceiver 830 part is mainly used for receiving and transmitting radio frequency signals and converting radio frequency signals into baseband signals; the transceiver 830 part can usually be called a transceiver module, a transceiver, a transceiver circuit, or a transceiver, etc. The transceiver module of the transceiver 830 part can also be called a transceiver or a transceiver, etc., which includes an antenna 833 and a radio frequency circuit (not shown in the figure), wherein the radio frequency circuit is mainly used for radio frequency processing. Alternatively, the device for implementing the receiving function in the transceiver 830 portion may be considered a receiver, and the device for implementing the transmitting function may be considered a transmitter, that is, the transceiver 830 portion includes a receiver 832 and a transmitter 831. The receiver may also be referred to as a receiving module, a receiver, or a receiving circuit, and the transmitter may be referred to as a transmitting module, a transmitter, or a transmitting circuit.

[0186] The processor 810 and memory 820 may include one or more boards, each of which may include one or more processors and one or more memories. The processor is used to read and execute programs in the memory to implement baseband processing functions and control the base station. If multiple boards are present, the boards may be interconnected to enhance processing capabilities. As an optional implementation, multiple boards may share one or more processors, multiple boards may share one or more memories, or multiple boards may simultaneously share one or more processors.

[0187] For example, in one implementation, the transceiver module of the transceiver 830 is used to execute the transceiver-related processes performed by the base station (first device) in the aforementioned method embodiment. The processor of the processor 810 is used to execute the processing-related processes performed by the base station in the aforementioned method embodiment.

[0188] It should be understood that Figure 8 This is only an example and not a limitation. The network device including the processor, memory and transceiver may not rely on Figure 8 The structure shown.

[0189] Figure 9This is an example of the composition of another communication device provided in an embodiment of the present application. The communication device can be a second device, which can be a terminal device, including but not limited to electronic devices such as mobile phones and smart wearable devices (such as smart watches). Taking a mobile phone as an example, the communication device can include a processor 910, an external memory interface 920, an internal memory 921, a display screen 930, a camera 940, an antenna 1, an antenna 2, a mobile communication module 950, and a wireless communication module 960.

[0190] It should be understood that the structure illustrated in this embodiment does not constitute a specific limitation on the communication device. In other embodiments, the communication device may include more or fewer components than shown, or may combine or separate certain components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0191] The processor 910 may include one or more processing units. For example, the processor 910 may include an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU). Different processing units may be independent devices or integrated into one or more processors.

[0192] It is understood that the interface connection relationship between the modules illustrated in this embodiment is only a schematic illustration and does not constitute a structural limitation on the communication device. In other embodiments of the present application, the communication device may also adopt different interface connection methods in the above embodiments, or a combination of multiple interface connection methods.

[0193] External memory interface 920 can be used to connect an external memory card, such as a Micro SD card, to expand the storage capacity of the communication device. The external memory card communicates with processor 910 via external memory interface 920 to implement data storage functions. For example, files such as music and videos can be stored on the external memory card.

[0194] The internal memory 921 can be used to store computer executable program code, and the executable program code includes instructions. The processor 910 executes various functional applications and data processing of the communication device by running the instructions stored in the internal memory 921. The internal memory 921 may include a program storage area and a data storage area. Among them, the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc. The data storage area can store data created during the use of the communication device (such as audio data, a phone book, etc.), etc. In addition, the internal memory 921 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, a universal flash storage (UFS), etc. The processor 910 executes various functional applications and data processing of the communication device by running the instructions stored in the internal memory 921, and / or the instructions stored in the memory provided in the processor.

[0195] The wireless communication function of the communication device can be implemented through antenna 1, antenna 2, mobile communication module 950, wireless communication module 960, modem processor and baseband processor.

[0196] Antenna 1 and Antenna 2 are used to transmit and receive electromagnetic wave signals. Each antenna in the communication device can be used to cover a single or multiple communication frequency bands. Different antennas can also be reused to improve antenna utilization. For example, antenna 1 can be reused as a diversity antenna for a wireless local area network. In other embodiments, the antennas can be used in conjunction with a tuning switch.

[0197] The mobile communication module 950 can provide solutions for wireless communications including 2G / 3G / 4G / 5G applied to communication devices. The mobile communication module 950 may include at least one filter, a switch, a power amplifier, a low noise amplifier (LNA), etc. The mobile communication module 950 can receive electromagnetic waves from the antenna 1, and filter, amplify, and process the received electromagnetic waves, and transmit them to the modulation and demodulation processor for demodulation. The mobile communication module 950 can also amplify the signal modulated by the modulation and demodulation processor, and convert it into electromagnetic waves for radiation through the antenna 1. In some embodiments, at least some of the functional modules of the mobile communication module 950 can be set in the processor 910. In some embodiments, at least some of the functional modules of the mobile communication module 950 can be set in the same device as at least some of the modules of the processor 910.

[0198] In some embodiments of the present application, the communication device initiates or receives a call request through the mobile communication module 950 and the antenna 1 .

[0199] Furthermore, an operating system runs on the aforementioned components. Examples include the iOS operating system, the Android operating system, and the Windows operating system. Application programs can be installed and run on the operating system. Those skilled in the art will readily appreciate that, for ease of description and brevity, the explanations and beneficial effects of any of the aforementioned communication devices can be found in the corresponding method embodiments provided above, and will not be further elaborated upon here.

[0200] Reference Figure 10 The present application also provides a schematic diagram of the structure of a computer program product. In some embodiments, the above Figure 3 or Figure 5 The disclosed methods may be implemented as computer program instructions encoded in a machine-readable format on a computer-readable storage medium or on other non-transitory media or articles of manufacture.

[0201] Figure 10 Schematically illustrates a conceptual partial view of an example computer program product including a computer program for executing a computer process on a computing device, arranged in accordance with at least some embodiments presented herein.

[0202] In one embodiment, the computer program product 1000 is provided using a signal bearing medium 1001. The signal bearing medium 1001 may include one or more program instructions 1002, which when executed by one or more processors may provide the above-mentioned Figure 3 Thus, for example, reference to Figure 3 In the embodiment shown in , one or more features of steps S101 to S104 may be undertaken by one or more instructions associated with the signal bearing medium 1001; Figure 5 In the embodiment shown in , one or more features of step S201 to step S202 may be undertaken by one or more instructions associated with the signal bearing medium 1001. In addition, Figure 10 Program instructions 1002 in also describe example instructions.

[0203] In some examples, the signal bearing medium 1001 may include a computer readable medium 1003 such as, but not limited to, a hard drive, a compact disk (CD), a digital video disk (DVD), a digital tape, a memory, a ROM or RAM, or the like.

[0204] In some embodiments, the signal-bearing medium 1001 may include a computer-recordable medium 1004, such as, but not limited to, a memory, a read / write (R / W) CD, a R / W DVD, or the like. In some embodiments, the signal-bearing medium 1001 may include a communication medium 1005, such as, but not limited to, a digital and / or analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communication link, a wireless communication link, or the like). Thus, for example, the signal-bearing medium 1001 may be communicated via a wireless form of the communication medium 1005 (e.g., a wireless communication medium conforming to the IEEE 802.15 standard or other transmission protocol).

[0205] The one or more program instructions 1002 may be, for example, computer-executable instructions or logic-implemented instructions. In some examples, the computing device may be configured to provide various operations, functions, or actions in response to the program instructions 1002 communicated to the computing device via one or more of computer-readable media 1003, computer-recordable media 1004, and / or communication media 1005.

[0206] Should be understood that the arrangement described here is only for the purpose of example. Thus, those skilled in the art will understand that other arrangements and other elements (such as, machines, interfaces, functions, sequences, and functional groups, etc.) can be used instead, and some elements can be omitted altogether according to the desired result. In addition, many of the described elements can be implemented as discrete or distributed components or in any appropriate combination and position in conjunction with the functional entities implemented by other components.

[0207] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described systems, devices and modules can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0208] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules is merely a logical function division. In actual implementation, there may be other division methods, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or module, which can be electrical, mechanical or other forms.

[0209] The modules described as separate components may or may not be physically separate, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules may be selected to achieve the purpose of the present embodiment according to actual needs.

[0210] In addition, the functional modules in the various embodiments of the present application may be integrated into a processing module, or each module may exist physically separately, or two or more modules may be integrated into a single module. The above-mentioned integrated modules may be implemented in the form of hardware or software functional modules.

[0211] If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the part that essentially contributes to the technical solution of the present application or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the process of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory, a random access memory, a magnetic disk or an optical disk.

[0212] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A cell selection method, characterized in that: The method is applied to a network device, and the method includes: Obtaining a signal arrival delay for each cell in the candidate cell set, and determining a signal arrival delay for a first target cell, where the first target cell is a cell in the candidate cell set, and the signal arrival delay of the first target cell is determined based on a first signal arrival time of the first target cell and a signal arrival time of a reference cell, where the first signal arrival time is determined by a terminal device based on measurement of a first target signal, and the reference cell is a cell in the candidate cell set with the smallest measured signal arrival time; In response to the signal arrival delay of the first target cell being greater than a delay threshold, a first cell switching instruction is not sent to the terminal device, where the first cell switching instruction is used to instruct the terminal device to access the first target cell.

2. The method according to claim 1, characterized in that The method further comprises: In response to the signal arrival delay of the first target cell being less than the delay threshold, the first cell switching instruction is sent to the terminal device.

3. The method according to claim 1, characterized in that After the response that the signal arrival delay of the first target cell is greater than a delay threshold, the method further includes: Determining a signal arrival delay of a second target cell, where the second target cell is a cell in the candidate cell set, and the signal arrival delay of the second target cell is determined based on a second signal arrival time of the second target cell and a signal arrival time of the reference cell, where the second signal arrival time is determined by the terminal device based on measurement of the second target signal; In response to the signal arrival delay of the second target cell being less than the delay threshold, a second cell switching instruction is sent to the terminal device, where the second cell switching instruction is used to instruct the terminal device to access the second target cell.

4. The method according to claim 1, wherein The determining the signal arrival delay of the first target cell includes: The arrival delay of the signal of the first target cell received from the terminal device.

5. The method according to claim 4, characterized in that The terminal device determines the signal arrival delay of the first target cell in the following manner: Wherein, the ΔT j is the signal arrival delay of the first target cell, min is the minimum operator, and Indicates the (T j –T0) / N step Do the floor operation, the T j is the arrival time of the first signal, T0 is the arrival time of the signal of the reference cell, and N step is the quantization step size, the N max is the ΔT j The reporting upper limit value.

6. The method according to claim 1, characterized in that The determining the signal arrival delay of the first target cell includes: Receiving the first signal arrival time sent by the terminal device and the signal arrival time of the reference cell; The signal arrival delay of the first target cell is determined based on the first signal arrival time and the signal arrival time of the reference cell.

7. The method according to claim 6, characterized in that The determining the signal arrival delay of the first target cell based on the first signal arrival time and the signal arrival time of the reference cell includes: The signal arrival delay of the first target cell is determined by: ΔT j =T j -T0; wherein, the T j is the arrival time of the first signal, T0 is the arrival time of the signal of the reference cell, and ΔT j is the signal arrival delay of the first target cell.

8. The method according to any one of claims 1 to 7, characterized in that After the response that the signal arrival delay of the first target cell is greater than a delay threshold, the method further includes: The first target cell is added to a blacklist cell list, where the blacklist cell list is used to indicate that the measurement result of the first target cell is not reported and / or to indicate that the first target cell is an inaccessible cell.

9. The method according to any one of claims 1 to 8, characterized in that The delay threshold is sent by the reference cell to the terminal device based on a broadcast message.

10. A cell selection method, characterized in that: The method is applied to a terminal device, and the method includes: Determine a first target cell from the set of candidate cells; determining a first signal arrival time of the first target cell based on a measurement of the first target signal; determining a signal arrival delay of the first target cell based on the first signal arrival time and a signal arrival time of a reference cell, wherein the reference cell is a cell in the set of candidate cells having a minimum measured signal arrival time; In response to a signal arrival delay of the first target cell being greater than a delay threshold, the first target cell is not accessed.

11. The method according to claim 10, characterized in that The method further comprises: In response to the signal arrival delay of the first target cell being less than the delay threshold, accessing the first target cell.

12. The method according to claim 10, characterized in that After the response that the signal arrival delay of the first target cell is greater than a delay threshold, the method further includes: Determine a second target cell from the set of candidate cells; Determining a second signal arrival time of the second target cell based on measurement of the second target signal; Determining a signal arrival delay of the second target cell based on the second signal arrival time and the signal arrival time of the reference cell; In response to the signal arrival delay of the second target cell being less than the delay threshold, accessing the second target cell.

13. The method according to any one of claims 10 to 12, characterized in that The method further comprises: Detect and obtain multiple cells; The candidate cell set is determined according to a reference signal received power RSRP of each cell in the multiple cells and a preset power threshold value; wherein the RSRP is determined based on measurement of a specific reference signal of the cell.

14. The method according to any one of claims 10 to 13, characterized in that The method further includes: receiving the delay threshold sent by the reference cell based on a broadcast message.

15. The method according to any one of claims 10 to 14, characterized in that The method further comprises: Obtaining a signal arrival time for each cell in the candidate cell set; The reference cell is determined according to a minimum value of the signal arrival times of each cell.

16. The method according to any one of claims 10 to 15, characterized in that The determining the signal arrival delay of the first target cell based on the first signal arrival time and the signal arrival time of the reference cell includes: The signal arrival delay of the first target cell is determined by: ΔT j =T j -T0; wherein, the T j is the arrival time of the first signal, T0 is the arrival time of the signal of the reference cell, and ΔT j is the signal arrival delay of the first target cell.

17. A network device, characterized in that: The network equipment includes: a delay acquisition unit, configured to acquire a signal arrival delay of each cell in the candidate cell set, and determine a signal arrival delay of a first target cell, wherein the first target cell is a cell in the candidate cell set, and the signal arrival delay of the first target cell is determined based on a first signal arrival time of the first target cell and a signal arrival time of a reference cell, the first signal arrival time being determined by a terminal device based on measurement of a first target signal, and the reference cell being a cell in the candidate cell set having the smallest measured signal arrival time; An instruction sending unit is used to not send a first cell switching instruction to the terminal device in response to the signal arrival delay of the first target cell being greater than a delay threshold, where the first cell switching instruction is used to instruct the terminal device to access the first target cell.

18. A terminal device, characterized in that: The terminal device includes: a cell determination unit, configured to determine a first target cell from a set of candidate cells; a signal measuring unit, configured to determine a first signal arrival time of the first target cell based on a measurement of the first target signal; a delay measurement unit, configured to determine a signal arrival delay of the first target cell based on the first signal arrival time and a signal arrival time of a reference cell, wherein the reference cell is a cell in the set of candidate cells having a minimum measured signal arrival time; The cell access unit is configured to not access the first target cell in response to a signal arrival delay of the first target cell being greater than a delay threshold.

19. A communication device, characterized in that: The communication device comprises: Memory for storing computer programs or computer instructions; A processor, configured to execute the computer program or computer instructions stored in the memory, so that the communication device performs the method according to any one of claims 1 to 9.

20. A communication device, characterized in that: The communication device comprises: Memory for storing computer programs or computer instructions; A processor, configured to execute the computer program or computer instructions stored in the memory, so that the communication device performs the method according to any one of claims 10 to 16.

21. A computer storage medium for storing a computer program, wherein when the computer program is executed, the computer program is used to implement the method according to any one of claims 1 to 9, or 10 to 16.

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