Communication method and apparatus

Abstract

A communication method and apparatus, which are applicable to a scenario in which a terminal device initially accesses a network. The method comprises: a network device sending first information, wherein the first information is used for indicating a first band list, and the first band list is used for indicating a band to which a first cell belongs; and a terminal device sending second information, wherein the second information is used for indicating a first band, and the first band belongs to the first band list. Since a terminal device indicates a first band to a network device, the network device and the terminal device have a consistent understanding of a band to be used, such that communication failures can be reduced. For example, the network device configures a carrier aggregation for the terminal device on the basis of the first band, and the terminal device sends random access on the first band on the basis of the carrier aggregation, such that network access failures of the terminal device can be reduced, thereby reducing the number of times the terminal device initiates reestablishment.

Description

A communication method and apparatus

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411575198.6, filed on November 6, 2024, entitled "A Communication Method and Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of communication technology, and in particular to a communication method and apparatus. Background Technology

[0004] Typically, after determining a suitable cell to camp on, a terminal device performs a band selection process based on its capabilities. The terminal device then determines relevant configurations (e.g., radio frequency configuration) based on the selected band. On the network side, network devices also configure appropriate parameters for the terminal device based on the band, such as carrier combinations.

[0005] The band selected by the network device may differ from the band selected by the terminal device. If the bands selected by the network device and the terminal device are inconsistent, normal communication will be affected. For example, if the carrier aggregation (CA) combination configured by the network device for the terminal device based on its selected band does not match the bandwidth capability of the band selected by the terminal device, the terminal device will need to rebuild the link, leading to service interruption. Summary of the Invention

[0006] This application provides a communication method and apparatus that can ensure that the band selected by the terminal device is consistent with the band selected by the network device, thereby reducing communication failures of the terminal device and improving the communication efficiency of the terminal device.

[0007] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0008] Firstly, a communication method is provided, which can be applied to a terminal-side device (also known as a terminal device). For example, the terminal device can be a terminal equipment or a module or unit for performing some functions of the terminal equipment, such as circuits or chip / chip system (e.g., a modem chip, also known as a baseband chip, or a system-on-chip (SoC) chip containing a modem core, or a system-in-package (SIP) chip) or other functional modules in the terminal equipment. Alternatively, the terminal device can be a logical node, logical module, or software module that implements all or part of the functions of the terminal equipment. For ease of description, the following example uses the application of this method to a terminal equipment.

[0009] The communication method includes: receiving first information and sending second information. The first information is used to indicate a first frequency band list, which indicates the frequency band to which the first cell belongs, and the second information is used to indicate a first frequency band that belongs to the first frequency band list.

[0010] The first cell is the cell where the terminal device camps, or the cell the terminal device attempts to access. The frequency band to which the first cell belongs can be understood as the frequency band where the carrier of the first cell resides. For example, if the carrier of the first cell is within a certain frequency band, then that frequency band is the frequency band to which the first cell belongs. The frequency band to which the first cell belongs can also be understood as one or more frequency bands indicated by the first cell. In this method, the terminal device selects a first frequency band from the list of first frequency bands and indicates the first frequency band to the network device. This allows the network device to clearly identify the frequency band selected by the terminal device as the first frequency band, and thus configure the terminal device according to the first frequency band (e.g., configure carrier combinations). In this way, the carrier combination configured by the network device for the terminal device matches the frequency band combination capability of the first frequency band selected by the terminal device, reducing communication failures of the terminal device.

[0011] Secondly, a communication method is provided that can be applied to a network-side device (also known as a network device). For example, the network device can be a network equipment, a component within the network equipment (e.g., a circuit, chip, or chip system), or a module or unit used to perform some or all of the functions of the network equipment, such as a central unit (CU), a distributed unit (DU), or a radio unit (RU). Alternatively, the network device can be a logical node, logical module, or software module that implements all or part of the functions of the network equipment. For ease of description, the following example illustrates the application of this method to a network device.

[0012] The communication method includes: sending first information and receiving second information. The first information indicates a first frequency band list, which indicates the frequency band to which the first cell belongs, and the second information indicates a first frequency band that belongs to the first frequency band list.

[0013] In this method, the network device can indicate the frequency band of the first cell (i.e., the first frequency band list) to the terminal device, enabling the terminal device to select a suitable frequency band (e.g., the first frequency band) from the first frequency band list for subsequent operations. For example, the terminal device can determine its own configuration (e.g., radio frequency configuration) based on the first frequency band. The network device, based on the second information received from the terminal device, can confirm that the frequency band selected by the terminal device is the first frequency band. Subsequently, the network device can configure the terminal device based on the first frequency band (e.g., configure carrier combinations). Thus, the carrier combination configured by the network device for the terminal device matches the frequency band combination capability of the first frequency band selected by the terminal device, reducing communication failures for the terminal device.

[0014] In one implementation of the first aspect, the method further includes: determining a first frequency band from a first frequency band list based on first information and the capabilities of the terminal device.

[0015] The terminal device determines the first frequency band based on the first frequency band list indicated by the network device and the capabilities of the terminal device. Thus, based on the fact that the network device supports the first frequency band, the first frequency band selected by the terminal device matches the capabilities of the terminal device, which can reduce the failure rate of communication based on the first frequency band.

[0016] In one implementation of the first or second aspect, the first frequency band satisfies one or more of the following conditions:

[0017] The terminal device supports the first frequency band;

[0018] The terminal equipment supports at least one transmit power spurious requirement in the first frequency band;

[0019] The terminal device supports an uplink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the uplink bandwidth part (BWP) bandwidth;

[0020] The terminal device supports a downlink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the downlink BWP bandwidth;

[0021] If the first cell indicates support for a 7.5kHz frequency offset, the terminal device supports a 7.5kHz frequency offset in the first frequency band; or if the first cell indicates support for a 7.5kHz frequency offset.

[0022] When the first cell indicates that it supports half-duplex (HD) frequency division duplexing (FDD) terminal equipment access, or when the terminal equipment supports full-duplex (FD) FDD on the first frequency band;

[0023] If the terminal device with the first feature is not prohibited from accessing the first cell, the terminal device supports the first feature in the first frequency band. The first feature includes the terminal device supporting one antenna channel or the terminal device supporting two antenna channels.

[0024] The conditions above are merely examples. As the capabilities of terminal devices or the configuration of network devices increase in the future, the first frequency band can meet more conditions. Terminal devices can select the first frequency band based on one or more of the above conditions, the configuration information of the network devices, and the capabilities of the terminal devices themselves, ensuring that the first frequency band matches the capabilities of the terminal devices and that the first frequency band is a frequency band supported by the network devices, thereby reducing the probability of communication failure on the first frequency band.

[0025] In one implementation of the first or second aspect, the first frequency band is the first frequency band in the list of first frequency bands that satisfies one or more of the above conditions.

[0026] Terminal devices can increase the flexibility of network device implementation by selecting the first frequency band that meets one or more of the above conditions. Network devices can prioritize frequency bands, ensuring that the terminal device selects a band that meets its capabilities and is of higher priority to the network device, thus improving communication quality.

[0027] In one implementation of the first or second aspect, the second information is carried in one or more of the following: a radio resource control (RRC) establishment completion message, an RRC recovery completion message, an RRC reconstruction completion message, a media / medium access control (MAC) layer control element (CE) message, or a random access message, wherein the random access message is used to send a first preamble, the first preamble corresponding to a first frequency band.

[0028] The terminal device can report the first frequency band to the network device through one or more of the above messages, so that the network device can clearly identify the frequency band selected by the terminal device as the first frequency band. This allows the network device to match the relevant configuration determined by the network device for the terminal device based on the capabilities related to the first frequency band with the capabilities of the terminal device, thereby reducing communication failures based on the first frequency band.

[0029] In one implementation of the first aspect, the method further includes: transmitting capability information of the terminal device and receiving third information, the third information including carrier configuration information. The carrier configuration information is related to the first frequency band and the capability information of the terminal device.

[0030] The terminal device reports its capability information to the network device, so that the network device can make relevant configurations for the terminal device based on the capability information (such as carrier combination configuration). If the configuration matches the capabilities of the terminal device, it can reduce communication failures of the terminal device.

[0031] In one implementation of the second aspect, the method further includes: receiving capability information of the terminal device, determining third information based on the capability information and the first frequency band, and transmitting the third information. The third information includes carrier configuration information.

[0032] Network devices can configure relevant settings (such as carrier combination configuration) for terminal devices based on their capabilities. In this way, the relevant settings provided by the network device for the terminal device match the capabilities of the terminal device, which can reduce communication failures of the terminal device.

[0033] Thirdly, a communication method is provided that can be applied to a terminal-side device. For details regarding this terminal-side device, please refer to the introduction in the first aspect. For ease of description, the following example uses the method applied to a terminal device.

[0034] The communication method includes: receiving first information, sending fourth information, and receiving fifth information. The first information indicates a first frequency band list, which indicates the frequency band to which the first cell belongs. The fourth information indicates a second frequency band list, where the frequency bands in the second frequency band list belong to the first frequency band list. The fifth information indicates a second frequency band, which belongs to a second frequency band list.

[0035] In this method, the terminal device can select an available frequency band from a first frequency band list (i.e., a second frequency band list) and indicate the second frequency band list to the network device, so that the network device can select the frequency band to be used by the terminal device from the available frequency bands (i.e., the second frequency band). Based on the fifth information sent by the network device, the terminal device can clearly confirm that the frequency band selected by the network device is the second frequency band, and the terminal device can perform configuration or communication based on the second frequency band. The terminal device can also assume that the configuration performed by the network device for the terminal device is also based on the second frequency band. Thus, by communicating on the second frequency band according to this configuration, the terminal device can reduce communication failures.

[0036] Fourthly, a communication method is provided that can be applied to network-side devices. For details on network-side devices, please refer to the description in the second aspect. For ease of description, the following example uses the application of this method to a network device.

[0037] The communication method includes: sending first information, receiving fourth information, and sending fifth information. The first information indicates a first frequency band list, which indicates the frequency band to which the first cell belongs. The fourth information indicates a second frequency band list, where the frequency bands in the second frequency band list belong to the first frequency band list. The fifth information indicates a second frequency band, which belongs to a second frequency band list.

[0038] In this method, the network device can determine the available frequency bands (i.e., the second frequency band list) of the terminal device based on the fourth information received from the terminal device. The network device can select a second frequency band from the second frequency band list for the terminal device to use and indicate the second frequency band to the terminal device. In this way, the network device and the terminal device have a consistent understanding of the frequency band to be used by the terminal device, which can reduce communication failures of the terminal device. For example, the network device can configure the terminal device according to the second frequency band (e.g., configure carrier combinations), and the terminal device can communicate according to the carrier configuration, which can reduce the failure of the terminal device to access the network, thereby reducing the number of times the terminal device initiates reconstruction.

[0039] In one implementation of the third aspect, the method further includes: determining a second frequency band list from a first frequency list based on first information and the capabilities of the terminal device.

[0040] The terminal device determines the second frequency band list based on the first frequency band list indicated by the network device and the capabilities of the terminal device. This allows the frequency bands in the second frequency band list to match the capabilities of the terminal device, based on the network device's support for the frequency bands in the second frequency band list, thereby reducing the failure rate of communication based on the frequency bands in the second frequency band list.

[0041] In one implementation of the third or fourth aspect, any frequency band in the second frequency band list satisfies one or more of the following conditions:

[0042] The terminal device supports this frequency band;

[0043] The terminal equipment supports at least one transmit power spurious requirement in this frequency band;

[0044] The terminal device supports one uplink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the uplink BWP bandwidth;

[0045] The terminal device supports a downlink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the downlink BWP bandwidth;

[0046] If the first cell indicates support for a 7.5kHz frequency offset, the terminal device supports a 7.5kHz frequency offset in that frequency band; or if the first cell indicates support for a 7.5kHz frequency offset.

[0047] If the first cell indicates support for HD-FDD terminal equipment access, or if the terminal equipment supports FD-FDD on the frequency band;

[0048] If the terminal device with the first feature is not prohibited from accessing the first cell, the terminal device supports the first feature in the frequency band, and the first feature includes the terminal device supporting one antenna channel or the terminal device supporting two antenna channels.

[0049] The conditions above are merely examples. As the capabilities of terminal devices or the configuration of network devices increase in the future, any frequency band in the second frequency band list can satisfy more conditions. Terminal devices can select frequency bands from the second frequency band list based on one or more of the above conditions, the configuration information of the network devices, and the capabilities of the terminal devices themselves. This ensures that the frequency bands in the second frequency band list are usable by the terminal devices and supported by the network devices, thereby reducing the probability of communication failures on the frequency bands in the second frequency band list.

[0050] In one implementation of the third or fourth aspect, the fourth information is carried in one or more of the following:

[0051] RRC establishment complete message, RRC recovery complete message, RRC reconstruction complete message, or MAC CE message.

[0052] The terminal device can report the frequency bands in the second frequency band list to the network device through one or more of the above messages, so that the network device can clearly know that the frequency band available to the terminal device belongs to the second frequency band list. In this way, the network device can determine the second frequency band to be used by the terminal device from the second frequency band list, and perform relevant configuration for the terminal device according to the second frequency band, so as to ensure that the configuration matches the capabilities of the terminal device as much as possible and reduce communication failures based on the second frequency band.

[0053] In one implementation of the third aspect, the method further includes: sending capability information of the terminal device and receiving sixth information, the sixth information including carrier configuration information related to the second frequency band and the capability information of the terminal device.

[0054] In one implementation of the fourth aspect, the method further includes: receiving capability information of the terminal device, determining a second frequency band in the second frequency band list based on the capability information, determining sixth information based on the capability information and the second frequency band, and sending the sixth information. The sixth information includes carrier configuration information.

[0055] The beneficial effects of the third or fourth aspect and its various implementations can be referred to the beneficial effects of the first or second aspect and its various implementations mentioned above, and will not be repeated here.

[0056] Fifthly, embodiments of this application provide a communication device that has the function of implementing the behavior in any of the method examples of the first to fourth aspects described above. The beneficial effects can be found in the relevant descriptions of the first to fourth aspects, which will not be repeated here. This function can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more units corresponding to the above-described functions.

[0057] In one possible design, the communication device includes corresponding means, modules, or units for performing the methods of any of the first to fourth aspects, which can be implemented in software, hardware, or a combination of software and hardware.

[0058] For example, the communication device includes a processing unit and / or a transceiver unit, which can perform the corresponding functions of the terminal device in the above embodiments. For example, these units can perform the corresponding functions of the terminal device in the first aspect described above, with the transceiver module receiving first information and sending second information. The first information indicates a first frequency band list, which indicates the frequency band to which the first cell belongs, and the second information indicates the first frequency band, which belongs to the first frequency band list. The processing module is used to determine the first frequency band. See the detailed description in the method examples for further details, which will not be repeated here. As another example, these units can perform the corresponding functions of the terminal device in the third aspect described above, with the transceiver module receiving first information, sending fourth information, and receiving fifth information. The first information indicates a first frequency band list, which indicates the frequency band to which the first cell belongs. The fourth information indicates a second frequency band list, where the frequency bands in the second frequency band list belong to the first frequency band list. The fifth information indicates a second frequency band, which belongs to the second frequency band list. The processing module is used to determine the second frequency band list. See the detailed description in the method examples for further details, which will not be repeated here.

[0059] For example, the communication device includes a processing unit and / or a transceiver unit. These units can perform the corresponding functions of the network device in the above embodiments, as detailed in the method examples, and will not be repeated here. For example, these units can perform the corresponding functions of the network device in the second aspect above. The transceiver module is used to send first information and receive second information. The first information is used to indicate a first frequency band list, which indicates the frequency band to which the first cell belongs. The second information is used to indicate a first frequency band, which belongs to the first frequency band list. The processing module is used to determine the first information. See the detailed description in the method examples for further details, and will not be repeated here. For example, these units can perform the corresponding functions of the network device in the fourth aspect above. The transceiver module is used to send first information, receive fourth information, and send fifth information. The first information is used to indicate a first frequency band list, which indicates the frequency band to which the first cell belongs. The fourth information is used to indicate a second frequency band list, where the frequency bands in the second frequency band list belong to the first frequency band list. The fifth information is used to indicate a second frequency band, which belongs to the second frequency band list. The processing module is used to determine the second frequency band. For details, please refer to the detailed description in the method example; it will not be repeated here.

[0060] The processing unit is also called a processing module or processor; the transceiver unit is also called a transceiver module or transceiver. The transceiver unit can implement both sending and receiving functions. When the transceiver unit implements the sending function, it can be called a sending unit (sometimes also called a sending module); when the transceiver unit implements the receiving function, it can be called a receiving unit (sometimes also called a receiving module). The sending unit and the receiving unit can be the same functional unit, called the transceiver unit, which can implement both sending and receiving functions; or, the sending unit and the receiving unit can be different functional units, and the transceiver unit is a collective term for these functional units.

[0061] In one possible design, the processing unit includes a baseband device, and the transceiver unit includes a radio frequency device.

[0062] Sixthly, embodiments of this application provide a communication device, which includes a communication interface and a processor. The processor is configured to execute the methods in any of the first to fourth aspects and any implementation thereof. This application does not limit the specific type of processor. For example, the processor can be a baseband device, a central processing unit (CPU), or other specific integrated circuits. As another example, the processor can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0063] Optionally, the communication device further includes a memory for storing computer programs (also referred to as code or instructions), data, etc. The processor is coupled to the memory and the communication interface. When the processor reads the computer program, data, etc., from the memory, the methods in any of the first to fourth aspects and any implementation thereof are executed.

[0064] In one design, the memory is located outside the communication device.

[0065] In one design, the memory is located within the communication device.

[0066] In one design, the processor and memory are integrated together.

[0067] In a seventh aspect, embodiments of this application provide a chip system including a processor and a communication interface for implementing the methods described in any of the first to fourth aspects. Optionally, the chip system further includes a memory. The memory stores a computer program (also referred to as code or instructions). The processor retrieves and executes the computer program from the memory, causing a device equipped with the chip system to perform the methods in any of the first to fourth aspects and any possible implementation thereof. The chip system may be composed of chips or may include chips and other discrete devices.

[0068] Eighthly, embodiments of this application provide a communication device including an input / output interface and logic circuitry. The input / output interface is used for inputting and / or outputting information. The input / output interface may be an interface circuit, an output circuit, an input circuit, a pin, or related circuitry, etc. The logic circuitry is used to execute the methods described in any of the first to fourth aspects.

[0069] The communication device in the eighth aspect can be a chip, the input circuit can be an input pin, the output circuit can be an output pin, and the logic circuit can be a transistor, gate circuit, flip-flop, and various other logic circuits. The input signal received by the input circuit can be received and input by, for example, but not limited to, a receiver, and the signal output by the output circuit can be, for example, but not limited to, output to a transmitter and transmitted by the transmitter. Furthermore, the input circuit and the output circuit can be the same circuit, which is used as both the input circuit and the output circuit at different times. This application does not limit the specific implementation of the input / output interface and the logic circuit.

[0070] In one implementation of the eighth aspect, when the communication device is a terminal device, the interface circuit can be a radio frequency processing chip in the terminal device, and the processing circuit can be a baseband processing chip in the terminal device. When the communication device is a network device, the interface circuit can be a radio frequency processing chip in the network device, and the processing circuit can be a baseband processing chip in the network device.

[0071] In specific implementation, the aforementioned communication device can be a terminal device as described in the first or third aspect. Alternatively, the communication device can be a device capable of supporting the terminal device in implementing the functions required by the methods provided in the first or third aspect; for example, the communication device can be a chip or chip system within the terminal device. Alternatively, the communication device can be a network device as described in the second or fourth aspect. Alternatively, the communication device can be a device capable of supporting the network device in implementing the functions required by the methods provided in the second or fourth aspect; for example, the communication device can be a chip or chip system within the network device. The chip can be a baseband chip and / or a radio frequency chip, and the chip system can be composed of chips or may include chips and other discrete components.

[0072] Ninthly, embodiments of this application provide a communication system, the communication system including a terminal device and a network device. The terminal device is used to implement the function of the method described in the first aspect, and the network device is used to implement the function of the method described in the second aspect; or, the terminal device is used to implement the function of the method described in the third aspect, and the network device is used to implement the function of the method described in the fourth aspect.

[0073] In a tenth aspect, embodiments of this application provide a computer-readable storage medium for storing a computer program or instructions that, when executed, cause the methods described in any of the first to fourth aspects and any implementation thereof to be implemented.

[0074] Eleventhly, embodiments of this application also provide a computer program product containing instructions that, when run on a computer, cause the methods described in any of the first to fourth aspects and any of their implementations to be implemented.

[0075] The beneficial effects of the fifth to eleventh aspects and their implementation methods can be referenced by the beneficial effects of the first to fourth aspects and any one of their implementation methods. Attached Figure Description

[0076] Figure 1 is a schematic diagram of the architecture of the communication system applicable to the embodiments of this application;

[0077] Figure 2 is a flowchart illustrating the first communication method provided in an embodiment of this application;

[0078] Figure 3 is a schematic diagram of the multi-band indication provided in an embodiment of this application;

[0079] Figure 4 is a flowchart illustrating the second communication method provided in an embodiment of this application;

[0080] Figure 5 is a flowchart illustrating the second communication method provided in an embodiment of this application;

[0081] Figure 6 is a schematic diagram of a communication device provided in an embodiment of this application;

[0082] Figure 7 is a schematic diagram of another structure of the communication device provided in the embodiment of this application. Detailed Implementation

[0083] The technical solutions provided in the embodiments of this application can be applied to various communication systems, such as long term evolution (LTE) communication systems, the sixth generation (5G) mobile communication systems / new radio (NR) communication systems, or they can also be applied to future mobile communication systems, or other similar communication systems. Other similar communication systems may include wireless fidelity (WIFI), vehicle-to-everything (V2X), internet of things (IoT) systems, non-terrestrial network (NTN) communication systems, and so on.

[0084] Please refer to Figure 1, which illustrates a communication system applicable to an embodiment of this application. The communication system includes a wireless access network 100 and a core network 200. Optionally, the communication system may also include an Internet 300 (Figure 1 uses this as an example).

[0085] The wireless access network 100 may include at least one network device and at least one terminal device. For example, the wireless access network 100 includes two network devices, 110a and 110b, and terminal devices 120a to 120j. The network architecture shown in Figure 1 is only schematic; the number of terminal devices and / or network devices may be fewer or more. The communication system described in the embodiments of this application is for the purpose of more clearly illustrating the technical solutions of the embodiments of this application and does not constitute a limitation on the communication system to which the embodiments of this application are applicable. For example, the communication system may also include other devices, such as wireless relay devices and wireless backhaul devices, which are not shown in Figure 1. As those skilled in the art will know, with the evolution of network architecture, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems. When applying the technical solutions of the embodiments of this application to other communication systems, the devices, components, modules, etc. in the embodiments can be replaced with corresponding devices, components, modules in other communication systems without limitation.

[0086] In this embodiment, network equipment refers to (radio)access network ((R)AN) equipment / RAN node. In this embodiment, (R)AN and RAN are interchangeable; for ease of description, RAN is used as an example below. RAN can be a cellular system related to the 3rd generation partnership project (3GPP), such as a 5G / NR mobile communication system or a future-oriented evolution system. RAN can also be an open RAN (O-RAN or ORAN), a cloud radio access network (CRAN), a virtualized RAN (vRAN), a non-terrestrial network (NTN), etc. RAN can also be a communication system that integrates two or more of the above systems. RAN equipment can also be called a RAN node, RAN entity, or access node, etc.

[0087] In one possible scenario, a RAN node can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), or a base station in a future mobile communication system. RAN nodes can also be macro base stations, micro base stations, indoor stations, relay nodes, donor / host nodes, or radio controllers. RAN nodes can also be servers, wearable devices, vehicles, or in-vehicle equipment. For example, in V2X technology, the RAN node can be a roadside unit (RSU).

[0088] In another possible scenario, the RAN node can be a module or unit that performs some of the functions of the base station; or multiple RAN nodes can cooperate to assist terminal equipment in achieving wireless access, with different RAN nodes performing some of the functions of the base station. For example, the RAN node can be a CU, DU, or RU. The function of the CU can be implemented by a single entity or by different entities. For example, the function of the CU can be further divided, that is, the control plane and the user plane can be separated and implemented by different entities, namely the control plane CU entity (i.e., CU-control plane (CP) entity) and the user plane CU entity (i.e., CU-user plane (UP) entity). The CU-CP entity and the CU-UP entity can be coupled with the DU to jointly complete the function of the RAN node. The CU and DU can be set up separately or included in the same network element, such as in the baseband unit (BBU). Any of the units among the CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented by software modules, hardware modules, or a combination of software modules and hardware modules.

[0089] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples.

[0090] The CU and DU can be configured according to the protocol layer functions of the wireless network they implement: for example, the CU can be configured to implement the functions of the Packet Data Convergence Protocol (PDCP) layer and above (such as the Radio Resource Control (RRC) layer and / or the Service Data Adaptation Protocol (SDAP) layer); the DU can be configured to implement the functions of protocol layers below the PDCP layer (such as the Radio Link Control (RLC) layer, the MAC layer, and / or the Physical (PHY) layer). For specific descriptions of the above protocol layers, please refer to the relevant 3GPP technical specifications or the technical specifications of other applicable communication protocols.

[0091] The above division of the processing functions of CU and DU according to protocol layers is merely an example; other division methods are also possible, and this application does not limit this. For example, in one design, CU or DU can be further divided into processing functions with protocol layers. In one design, some functions of the RLC layer and the functions of the protocol layer above the RLC layer are located in the CU, while the remaining functions of the RLC layer and the functions of the protocol layer below the RLC layer are located in the DU.

[0092] In another possible design, the DU and RU collaborate to implement the PHY layer functionality, or, more specifically, a portion of the PHY layer functionality of the DU can be moved to the RU. A DU can be connected to one or more RUs. The functions of the DU and RU can be configured in various ways depending on the design. For example, the DU may be configured to implement baseband functions, and the RU may be configured to implement mid-RF functions. Alternatively, the DU may be configured to implement higher-level functions in the PHY layer, and the RU may be configured to implement lower-level functions in the PHY layer, or both lower-level and RF functions. Higher-level functions in the physical layer may include a portion of the physical layer's functionality closer to the MAC layer, and lower-level functions may include another portion of the physical layer's functionality closer to the mid-RF side. This application does not limit the specific functions of the DU and RU. The interface between the DU and RU can be called a fronthaul interface. In one design, the CU may not have a PDCP layer; for example, the CU may only include an RRC layer. The CU-CP may not have PDCP-C. The CU-UP may not have PDCP-U, or may not have a CU-UP. In one design, the DU may not have an RLC layer; for example, the DU may only have a MAC and a higher PHY layer.

[0093] When the RAN is O-RAN, it can also have artificial intelligence (AI) capabilities. For example, O-RAN includes an intelligent controller. The intelligent controller can be a non-real-time RAN intelligent controller (RIC / non-RT RIC / NRT RIC) or a near-real-time RAN intelligent controller (RIC / near-RT RIC / nRT RIC). A non-real-time RIC can be used to implement non-real-time intelligent management of RAN functions, enabling workflows including model training and model updates, and guiding applications / functions in the nRT RIC based on policies. A near-real-time RIC can be used to implement near-real-time intelligent management of the RAN. Through data collection and related operations on the E2 interface, near-real-time control and optimization of O-RAN modules and resources are achieved.

[0094] In the embodiments of this application, the device for implementing the functions of the network device can be the terminal device itself, or it can be a device that supports the network device in implementing the functions, such as a chip system or a combination of devices or components that can implement the functions of the network device. This device can be installed in the network device. The embodiments of this application do not limit the specific technology or specific device form used in the network device.

[0095] In this application embodiment, anything capable of data communication with a base station can be considered a terminal device. Terminal devices are also called terminals, terminal equipment, user equipment (UE), mobile stations, or mobile terminals, etc. Terminal devices can be widely used in various scenarios. For example, terminal devices can be: mobile phones, computers, mobile internet devices (MID), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, stations (STA), robotic arms, cameras, robots, vehicles, drones, helicopters, airplanes, ships, or smart home devices (such as televisions, air conditioners, robot vacuums, speakers, set-top boxes), relays, customer premises equipment (CPE), etc.

[0096] Furthermore, in this embodiment, the terminal device can also be a terminal device in an IoT system, such as a water meter or electricity meter. IoT is an important component of future information technology development. Its main technical characteristic is connecting objects to networks through communication technology, thereby realizing an intelligent network that enables human-machine interconnection and object-to-object interconnection.

[0097] When the terminal device is applied to V2X, it can also be called a V2X device, such as a smart car, an unmanned car, a driverless car, a pilotless car, or an automobile, or a roadside unit (RSU). All the terminal devices described above, if located on a vehicle (e.g., placed / installed inside the vehicle), can be considered in-vehicle terminal devices. In-vehicle terminal devices can be built into a vehicle's on-board module, on-board unit, on-board component, on-board chip, or on-board unit as one or more components or units. The vehicle can implement the methods of this application through the built-in on-board module, on-board unit, on-board component, on-board chip, or on-board unit. In-vehicle terminal devices can be vehicle equipment, on-board modules, vehicles, on-board units (OBU), RSUs, in-vehicle infotainment systems (or on-board transmitting units) (telematics boxes, T-boxes), chips, or SoCs, etc., and the aforementioned chips or SoCs can be installed in the vehicle, OBU, RSU, or T-box.

[0098] In the embodiments of this application, the device for implementing the functions of the terminal device can be the terminal device itself, or a device capable of supporting the terminal device in implementing the functions, such as a chip system or a combination of devices or components capable of implementing the functions of the terminal device. This device can be installed in the terminal device. The embodiments of this application do not limit the specific technology or specific device form used in the terminal device.

[0099] The communication system applicable to the embodiments of this application has been described above. To facilitate understanding of the technical solutions provided by the embodiments of this application, the relevant terms and other information involved in the embodiments of this application will be explained below.

[0100] (1) Carrier aggregation

[0101] Carrier aggregation refers to providing services to terminal devices simultaneously using multiple carriers. By aggregating multiple component carriers (CCs) to provide services to terminal devices at the same time, communication bandwidth and peak data rates can be increased. Each carrier can have at least one serving cell component carrier operating for the terminal device. In carrier aggregation technology, typically one carrier is the primary carrier (primary CC, PCC) or primary cell (primary cell, PCell), and the other carriers are secondary carriers (secondary CCs, SCCs) or secondary cells (secondary cells, Scells). Scells can be activated or deactivated during use. For example, if there is no data transmission for a period of time, the network can deactivate the Scell, and then reactivate it when data transmission resumes.

[0102] Carrier aggregation is divided into intra-band carrier aggregation and multi-band (or band combination) carrier aggregation. Intra-band carrier aggregation refers to the aggregation of multiple carriers on a single band, while multi-band carrier aggregation refers to the aggregation of multiple carriers across multiple bands. For example, in a band combination including band A, band B, and band C, band A has one carrier, band B has two carriers, and band C has two carriers. The carrier aggregation of this band combination can be achieved by aggregating the one carrier from band A, the two carriers from band B, and the two carriers from band C.

[0103] (2) Capabilities of terminal equipment

[0104] In order to better serve terminal devices, network devices need to know the capabilities of the terminal devices in order to configure and schedule them.

[0105] In the embodiments of this application, the capabilities of the terminal device include, but are not limited to, one or more of the following: supported frequency bands, supported carrier blocks (BCs), supported secondary cells (SCells), supported number of carrier blocks (CCs), maximum supported number of multiple-input multiple-output (MIMO) layers, and measurement interval capabilities. Frequency band combinations can be used to express the CA combinations and dual connectivity (DC) capabilities supported by the UE. A frequency band can also be called a frequency range, and each frequency band corresponds to a frequency range. Each frequency band in each frequency band combination can include one or more continuous or non-contiguous carriers. In the embodiments of this application, a frequency band can also be a frequency / frequency point. The frequency band list in this application only represents one or more frequency bands, and can also be described as a frequency band list or other names, without limitation.

[0106] In 5G systems, the capabilities of terminal devices can be divided into several levels, including but not limited to: terminal device-level capabilities, frequency band-level capabilities, and frequency band combination-level capabilities.

[0107] (2-1) Terminal device level capabilities (also known as per UE capabilities), such as the protocol version supported by the terminal device, PDCP layer capabilities, MAC layer capabilities, etc.

[0108] (2-2) Band-level capabilities (also known as per-band capabilities) are band-related capabilities, typically associated with the radio frequency capabilities of the terminal device. The capabilities of a terminal device include a supported band list, which contains an identifier for each supported band and the corresponding band-level capabilities.

[0109] (2-3) Band combination (BC) level capability (also known as per BC capability) is a BC-related capability, primarily related to the carrier aggregation and dual connectivity capabilities supported by the terminal device. The BCs supported by a terminal device are typically related to its radio frequency (RF) and baseband capabilities. The terminal device's capabilities include a list of BCs it supports. For a given BC, the terminal device needs to indicate information about the frequency bands included in that BC, such as the identifiers of each frequency band included in the BC.

[0110] A frequency band combination can consist of one or more frequency bands and the carriers included in the frequency bands that the terminal device supports configuring for carrier aggregation or dual connectivity. In other words, for a frequency band combination reported by the terminal device, the network device can configure the carriers included in the frequency bands of the frequency band combination for the terminal device to perform carrier aggregation or dual connectivity transmission.

[0111] It's important to note that a band can support multiple consecutive carriers or only a single carrier. When a terminal device only supports one band, its capabilities are also reported via a BC (Band Controller), which in this case includes only one band.

[0112] (2-4) Per-band per-BC capability (also known as per-band per-BC capability) refers to the capability for a specific band within a BC, and is usually related to the RF capabilities of the terminal device. Each BC corresponds to a feature set combination (FSC). The FSC contains the feature set (FS) corresponding to each band within that BC, which is the per-band per-BC capability, also known as per-FS capability.

[0113] Both per-band per BC level capabilities and per-band capabilities are band-specific capabilities. The difference lies in that per-band per BC level capabilities target a specific band within a given BC, while per-band capabilities are general capabilities for that band. For example, if a terminal device reports support for capability A in the per-band level capabilities of band A, then capability A should be supported on band A in all BCs composed of band A (e.g., band A + band B or band A + band C). However, for per-band per BC level capabilities, if a terminal device reports support for capability B on band A in a band A + band B combination, then band A in a band A + band C combination may report support for capability B. In essence, capability A belongs to the per-band level capabilities, and capability B belongs to the per-band per BC level capabilities.

[0114] (2-5) Carrier-level capability (also known as per CC capability) refers to the capability of component carriers within a frequency band combination. In per CC capability information, each component carrier is associated with a feature set per CC (FSPC) to indicate the capability of the corresponding component carrier; therefore, per CC capability is also called FeatureSetPerCC capability. Each FSPC includes FeatureSetDownlinkPerCC cells for reporting downlink transmission capability and FeatureSetUplinkPerCC cells for reporting uplink transmission capability, indicating the uplink and downlink transmission capabilities of the terminal equipment, respectively.

[0115] (3) Multi-frequency band indicator (MFBI)

[0116] MFBI is a mechanism for indicating multiple supported frequency bands, facilitating more flexible spectrum resource management. In an MFBI scenario, the frequency band list broadcast by network devices includes more than one band.

[0117] (4) The process of UE camping and band selection

[0118] After receiving the cell's system information (e.g., system information block (SIB) 1), the UE can determine whether it can camp on the cell based on the content indicated by SIB1 and the UE's capabilities. Determining whether the UE can camp on the cell can also be replaced by the UE determining whether the cell is barred, or whether it is not barred. In the case of MFBI, the UE also selects a band from multiple bands in the frequency band list (e.g., frequency band list) broadcast by the network device as its subsequent working band.

[0119] The process of the UE determining whether to camp and select a band includes the UE determining whether there exists a band that satisfies the following conditions (i.e., conditions a) to f). If there is a band that satisfies all of the following conditions a) to f), the UE determines that it can camp; otherwise, the UE considers the cell to be barred. If the UE can camp, the UE selects the first band that satisfies all of the following conditions a) to f).

[0120] a) The UE supports and the network device indicates the band in the cell's frequency band list (e.g., frequencyBandList);

[0121] b) The UE supports transmit power spurious requirements (e.g., additional Spectrum Emission) indicated by at least one network device on this band in a power list (e.g., nr-NS-PmaxList);

[0122] c) The UE supports an uplink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the uplink BWP bandwidth; and the UE supports a downlink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the downlink BWP bandwidth.

[0123] d) If the cell indicates support for a 7.5 kHz frequency offset, the UE supports a 7.5 kHz frequency offset over that bandwidth; or, if the cell does not indicate support for a 7.5 kHz frequency offset.

[0124] e) If the UE is a reduced capability (RedCap) UE or an enhanced RedCap ((e)RedCap), the cell indicates support for HD-FDD UE access, or the UE supports FD-FDD on the FDD band; understandably, if the UE does not belong to the above UE types, this condition does not need to be determined.

[0125] f) If the UE is a (e) RedCap UE, the UE supports one antenna channel (1Rx branch) on this band and the base station does not prohibit 1Rx branch access; or the UE supports two antenna channels (2Rx branches) on this band and the base station does not prohibit 2Rx branches access; it is understood that if the UE does not belong to the above UE types, this condition does not need to be determined.

[0126] (5) In the embodiments of this application, "transmission" includes "sending" and / or "receiving". "Sending" and "receiving" indicate the direction of signal transmission. For example, "sending information to XX" can be understood as the destination of the information being XX, which may include direct transmission via the air interface or indirect transmission by other units or modules via the air interface. "Receiving information from YY" can be understood as the source of the information being YY, which may include direct reception from YY via the air interface or indirect reception from YY by other units or modules via the air interface. "Sending" can also be understood as the "output" of the chip interface, and "receiving" can also be understood as the "input" of the chip interface. In other words, sending and receiving can occur between devices, such as between access network devices and terminal devices, or within a device, such as between components, modules, chips, software modules, or hardware modules within the device via a bus, wiring, or interface.

[0127] In this application embodiment, the number of nouns, unless otherwise specified, refers to "singular nouns or plural nouns," that is, "one or more." "At least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A / B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. For example, A / B means: A or B. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and / or c means the following combinations: a exists alone, b exists alone, c exists alone, a and b exist simultaneously, a and c exist simultaneously, b and c exist simultaneously, or a, b, and c exist simultaneously, where a, b, and c can be single or multiple.

[0128] In the embodiments of this application, "when," "if," and "if" all refer to the device taking corresponding actions under certain objective circumstances, and are not time-limited, nor do they require the device to perform a judgment action, nor do they imply any other limitations. Unless otherwise specified, "if" and "if" can be substituted, and "when" and "in the case of" can be substituted. "When" and "if" / "if" can be substituted.

[0129] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0130] In this application's embodiments, ordinal numbers such as "first" and "second" are used to distinguish multiple objects, and are not used to limit the size, content, order, timing, priority, or importance of the multiple objects. For example, "first frequency band list" and "second frequency band list" refer to two different frequency band lists, and do not indicate a difference in the priority or importance of these two frequency band lists.

[0131] In the embodiments of this application, the solutions in each embodiment can be used in a reasonable combination, and the explanations or descriptions of various terms, similar operations, or steps appearing in the embodiments can be referenced or explained to each other in the embodiments, without limitation.

[0132] The above describes some terms used in the embodiments of this application. The following describes the technical problems to be solved by the embodiments of this application.

[0133] When the UE is in idle or inactive mode, or during an RRC reconstruction process, the UE determines whether it can camp on that cell based on the cell's system information. If the UE can camp on that cell, it selects a frequency band from the frequency band list indicated by the cell. After selecting a band, the UE can determine some of its own configurations based on the selected band. For example, the UE can determine available frequency band combinations or radio frequency configuration information based on the selected band. When the UE enters connected mode in that cell, the network device to which that cell belongs can obtain UE capabilities from the UE, from the core network device, or from other network devices (such as the UE's previous serving network device). The network device can configure some parameters for the terminal device based on the obtained UE capabilities to communicate with the terminal device. For example, the network device can configure CA for the UE based on the BC capabilities reported by the UE, expecting the UE to use this CA configuration to communicate with the network device. It is understandable that if the band on which the network device configures the CA combination is inconsistent with the band selected by the UE, it may lead to CA combination configuration errors / failures. The UE will consider the CA configuration to be failed, triggering link reconstruction, resulting in communication interruption and affecting user experience.

[0134] To ensure that the band used by the network device to configure the terminal device is consistent with the band selected by the terminal device, one approach is to expect the network device to select the band according to the UE's band selection rules, thus guaranteeing consistency / alignment between the band selected by the network device and the band selected by the UE. However, as described in the aforementioned UE band selection process, the UE needs to consider multiple UE capabilities when selecting a band, requiring the network device to also be aware of these capabilities. However, some UE capabilities (such as whether the UE supports frequency offset on a specific band) cannot be reported via UE capability signaling. For example, the current protocol only stipulates that the UE must force support frequency offset on specific bands (e.g., FDD and SUL bands), but whether it supports frequency offset on other bands (e.g., TDD band) is undetermined; that is, the network device cannot accurately determine whether the terminal device supports frequency offset on a specific band. On the other hand, according to the principle of compatibility, as the protocol evolves, UE capabilities and / or network configurations will also evolve, increasing the conditions the UE needs to consider when selecting a band. If the network device uses the same rules as the UE to select a band, it needs to ensure that all relevant UE capabilities are aligned between the UE and the network device during the band selection process. In addition, for the existing bands, if new selection conditions are added later, new UE capabilities are needed to distinguish whether traditional UEs support the relevant capabilities, resulting in poor compatibility.

[0135] As the above analysis shows, if network devices do not select bands according to the same rules or cannot know all the relevant capabilities of the UE, there will be a situation where the band determined by the network device is inconsistent with the band selected by the UE. When the band on which the network device determines the UE's configuration is based is inconsistent with the band selected by the UE, the network device's configuration of the UE will be incorrect, which may lead to the UE and the network device being unable to communicate normally. For example, the frequency band list indicated by the network device to the UE includes the n77 and n78 frequency bands, and the UE also supports the n77 and n78 frequency bands. The network device selects the n77 band for the terminal device, and the network device configures the CA combination for the UE as n77+n2 based on the UE's reported capabilities in the n77 band, where n77 is used for the primary cell and n2 is used for the secondary cell; the UE selects the n78 band. When the UE receives the secondary cell configuration on the n2 band, since the UE believes that the primary cell is in the n78 band, the UE will consider the CA configuration to be incorrect because it does not support the n78+n2 frequency band combination, triggering RRC reconstruction and causing communication interruption.

[0136] To address the aforementioned problems, a method according to embodiments of this application is provided. The method provided by embodiments of this application enables the network device to configure the terminal device using a band that is consistent / aligned with the band selected by the terminal device, thereby minimizing the number of RRC reconstructions and reducing communication interruptions.

[0137] The communication method provided in the embodiments of this application is described below.

[0138] In the following description, taking the communication method provided in this application embodiment applied to the network architecture shown in Figure 1 as an example, the communication method provided in this application embodiment can be executed by a first communication device and a second communication device. In the following description, the first communication device is a network device and the second communication device is a terminal device as an example. The steps executed by the network device can be implemented by the RAN device itself, or by components in the RAN device (such as a baseband chip, or other processing units or processor modules), or by components that complete some or all of the functions of the RAN device (such as CU, DU, or RU). The steps executed by the terminal device can be implemented by the terminal device itself, or by components in the terminal device (such as a baseband chip, or other processing units or processor modules). There are no restrictions on the specific form of the network device and the terminal device; for example, the network device can be a chip, and the terminal device can be a device; or, both the network device and the terminal device can be chips or devices. In possible scenarios, the terminal device can be the terminal device 120a shown in Figure 1, or it can be the chip (system) in the terminal device 120a in Figure 1; the network device can be the network device 110a shown in Figure 1, or it can be the chip (system) in the network device 110a in Figure 1.

[0139] First, we will introduce the first communication method provided in the embodiments of this application.

[0140] In the first communication method, after determining that a cell is suitable for camping, the terminal device performs a band selection process, notifying the network device of the selected band (i.e., the first frequency band in this paper). The network device then configures relevant parameters for the terminal device based on the first frequency band and the terminal device's capabilities, such as configuring carrier combinations. In this way, the frequency band on which the network device configures parameters for the terminal device is consistent with the frequency band selected by the terminal device. This minimizes the mismatch between the carrier combinations configured by the network device and the terminal device's capabilities, thereby reducing the failure rate of the terminal device accessing the network within the first frequency band and reducing the number of RRC reconstructions initiated by the terminal device.

[0141] Please refer to Figure 2, which is a flowchart illustrating the first communication method provided in this embodiment. Figure 2 illustrates the method from the perspective of interaction between network devices and terminal devices. It should be understood that this communication method can also be implemented by other devices, such as a chip or communication device with communication capabilities. Furthermore, the processing performed by a single execution entity can be divided into multiple execution entities, which can be logically and / or physically separated. For example, the processing performed by the network device can be divided into execution by at least one of CU, DU, RU, etc. As shown in Figure 2, the flowchart of the first communication method provided in this embodiment includes the following steps.

[0142] S201. The network device sends the first information. Correspondingly, the terminal device receives the first information.

[0143] The first information is used to indicate a first frequency band list, or the first information may indicate a first frequency band list, which indicates the frequency band to which the first cell belongs. The first cell is the cell that the terminal device is currently attempting to camp on or access, or the first cell is the serving cell of the terminal device. The frequency band to which the first cell belongs can be replaced by any of the following descriptions: the frequency band to which the carrier of the first cell belongs, the frequency band to which the carrier belongs, or the frequency band in which the carrier of the first cell is located. The frequency band in which the carrier of the cell is located refers to the frequency range of the carrier of the cell falling within the frequency range of the frequency band.

[0144] The first frequency band list can indicate one or more frequency bands. The first frequency band list can indicate the included frequency bands by their band numbers. For example, if the first frequency band list includes the number of one frequency band, the first frequency band list indicates that frequency band. As another example, if the first frequency band list includes the numbers of multiple frequency bands, the first frequency band list indicates these multiple frequency bands. The case where the first frequency band list indicates multiple frequency bands can be considered as MFBI (Multiple Frequency Bands Identified). When the first frequency band list includes more than one frequency band (at least two frequency bands), the cell's carrier is located within the overlapping portion of these more than one frequency band (at least two frequency bands). As shown in Figure 3, in the case of MFBI, assuming the first frequency band list includes frequency bands numbered n77 and n78, the frequency range of the cell's carrier is located within the overlapping frequency range of frequency bands numbered n77 and n78.

[0145] Optionally, the first information can be carried in SIB1, or in other words, the first information can be an information element in SIB1. For example, the first information is the information element frequencyBandList in SIB, which includes the numbers of one or more frequency bands and can indicate the list of first frequency bands.

[0146] Optionally, the terminal device is in a disconnected state (e.g., idle state, or inactive state), or the terminal device is undergoing an RRC reconstruction process (e.g., the terminal device is in a connected state and timer T311 is running).

[0147] S202. The terminal device determines the first frequency band based on the first information and the terminal device's capability information.

[0148] The first frequency band is a frequency band supported by the terminal device. Furthermore, the first frequency band is either the frequency band selected by the terminal device, the frequency band selected by the terminal device for access or communication, or the frequency band the terminal device intends to access or communicate in. The first frequency band is a frequency band in the first frequency band list, meaning the first frequency band list includes the first frequency band. S202 can be replaced by: the terminal device determining the first frequency band from the first frequency band list, or the terminal device determining the first frequency band from the first frequency band list based on the terminal device's capability information.

[0149] When the terminal device receives the first information, it can perform a frequency band selection process based on the first information and the terminal device's capability information to determine a frequency band (i.e., the first frequency band) from the first frequency band list. The process by which the terminal device determines the first frequency band from the first frequency band list based on the first information and the terminal device's capability information can be referred to the aforementioned UE band selection process, and will not be repeated here. The terminal device's capabilities include one or more of the following: the terminal device's ability to support radio frequency power spurious emissions; the terminal device's ability to support uplink channel bandwidth; the terminal device's ability to support downlink channel bandwidth; the terminal device's ability to support frequency offset; the terminal device's ability to support HD-FDD; and the terminal device's ability to support the first feature.

[0150] The first frequency band selected by the terminal device satisfies one or more of the following conditions:

[0151] A) The terminal device supports the first frequency band;

[0152] The terminal device supports the first frequency band, which can also be understood as / replaced as the terminal device reporting the supported frequency bands in the UE capabilities, including the first frequency band.

[0153] B) The terminal equipment supports at least one transmit power spurious requirement in the first frequency band;

[0154] The terminal device receives a first frequency band list from the network device, obtains the transmit power spurious requirements corresponding to the frequency bands in the first frequency band list, and then determines whether it supports at least one transmit power spurious requirement corresponding to the first frequency band. The terminal device can select the frequency band corresponding to the supported transmit power spurious requirements. If the terminal device supports at least one transmit power spurious requirement corresponding to the first frequency band, then the terminal device can select the first frequency band.

[0155] C) The terminal device supports an uplink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the uplink BWP bandwidth; and the terminal device supports a downlink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the downlink BWP bandwidth.

[0156] The aforementioned uplink BWP can be the initial uplink BWP or a (e)RedCap UE-specific uplink BWP. The aforementioned downlink BWP can be the initial downlink BWP or a (e)RedCap UE-specific downlink BWP.

[0157] D) If the first cell indicates that frequency offset is supported, the terminal device supports frequency offset in the first frequency band; or the first cell indicates that frequency offset is supported.

[0158] The first cell supports frequency offset, which can be defined as the first cell supporting a 7.5kHz frequency offset. The first cell indicating support for frequency offset can be understood as the first cell indicating that NR uplink transmission is enabled to be offset onto the LTE grid.

[0159] Network devices can use frequencyShift7p5khz to indicate that the first cell supports frequency offset, and this indication can be included in SIB1.

[0160] E) If the first cell indicates support for HD-FDD terminal equipment access, or if the terminal equipment supports FD-FDD on the first frequency band;

[0161] Optionally, if the terminal device is (e)RedCap UE, then the first frequency band selected by the terminal device needs to satisfy condition E). Otherwise, if the terminal device is not (e)RedCap UE, then the first frequency band selected by the terminal device does not need to satisfy condition E).

[0162] Optionally, if the first frequency band is an FDD band, then the first frequency band selected by the terminal device needs to meet this condition E). Otherwise, if the first frequency band is not an FDD band (e.g., a TDD band), then the first frequency band selected by the terminal device does not need to meet this condition E).

[0163] F) If the terminal device with the first feature is not prohibited from accessing the first cell, the terminal device supports the first feature in the first frequency band.

[0164] The first characteristic may include the terminal device supporting one antenna channel (Rx branch) or the terminal device supporting two antenna channels. Condition F) can be understood as follows: if the first cell does not prohibit the access of a terminal device supporting one antenna channel, the terminal device supports one antenna channel in the first frequency band; or if the first cell does not prohibit the access of a terminal device supporting two antenna channels, the terminal device supports two antenna channels in the first frequency band.

[0165] The first feature can also be other terminal device features, which will not be described in detail here.

[0166] Optionally, the first frequency band selected by the terminal device needs to satisfy all of the conditions A) to F) above. That is, the terminal device selects the first frequency band from the list of first frequency bands that satisfies the conditions A) to F) above.

[0167] Optionally, if only one frequency band in the first frequency band list satisfies conditions A) to F), then the first frequency band is that frequency band. If there are multiple frequency bands in the first frequency band list that satisfy conditions A) to F), the first frequency band can be the first of these multiple frequency bands.

[0168] The terminal device determines the first frequency band based on the first information and its capabilities. Alternatively, the terminal device may determine the first frequency band in the first frequency band list that meets one or more of the above conditions, or the terminal device may determine the first frequency band in the first frequency band list that meets all of the above conditions. The first frequency band that meets one or more of the above conditions is, the first frequency band that satisfies one or more of the above conditions. Selecting the first frequency band from the first frequency band list that meets one or more (or all) of the above conditions increases the flexibility of network device implementation. The network device can prioritize frequency bands that meet its own capabilities, thus ensuring that the frequency band selected by the terminal device meets its own capabilities and is of higher priority to the network device, thereby maximizing communication quality.

[0169] S203. The terminal device sends the second information, and the network device receives the second information accordingly.

[0170] The second information may indicate the first frequency band, or it may be used to indicate the frequency band selected by the terminal device, or it may be used to indicate the frequency band selected by the terminal device according to S202. Optionally, the second information may indicate the first frequency band selected by the terminal device according to its capabilities / rules, or it may indicate both the first frequency band and the rules for selecting the first frequency band. The terminal device indicates the first frequency band to the network device through the second information. Upon receiving the second information, the network device can clearly identify the frequency band selected by the terminal device as the first frequency band. Therefore, the network device can configure relevant parameters for the terminal device based on the first frequency band and the capabilities of the terminal device, such as configuring carrier combinations. In this way, the frequency band on which the network device configures parameters for the terminal device is consistent with the frequency band selected by the terminal device, minimizing the mismatch between the carrier combinations configured by the network device and the capabilities of the terminal device, and ensuring normal communication between the terminal device and the network device as much as possible.

[0171] Optionally, if the first frequency band list includes more than one frequency band (or MFBI), the terminal device sends the second information to the network device. If the first frequency band list includes only one frequency band, both the terminal device and the network device use / select that frequency band, so the terminal device does not need to send the second information to the network device, which can save signaling overhead and conserve radio resources.

[0172] The second information may be carried in one or more of the following: RRC establishment complete message / RRC connection establishment complete message, RRC recovery complete message, RRC reconstruction complete message, MAC CE, or random access message.

[0173] For example, the second information may be carried in (or be) an RRC Setup Complete message. When a terminal device in an idle state accesses a network device, it will execute a connection establishment process. During this process, the terminal device sends an RRC Setup Complete message to the network device. This message may carry the second information to indicate the first frequency band. Upon receiving the RRC Setup Complete message, the network device can determine that the terminal device has selected the first frequency band based on the first frequency band indicated by the second information, and then determine the terminal device's configuration based on the first frequency band.

[0174] For example, the second information may be carried in (or be) an RRC recovery complete message (RRCResumeComplete). After a connection interruption, the terminal device may be in an inactive state. An inactive terminal device can restore the connection, for example, by performing an RRC recovery process. During the connection recovery process, the terminal device sends an RRC recovery complete message to the network device. This RRC recovery complete message may carry the second information to indicate the first frequency band. After receiving the RRC recovery complete message, the network device determines that the terminal device has selected the first frequency band based on the frequency band indicated by the second information, and then determines the terminal device's configuration based on the first frequency band.

[0175] For example, the second information can be carried in (or be) an RRC Reestablishment Complete message. In cases of link failure or handover failure, the terminal device can attempt to re-establish the connection; for example, the terminal device may execute an RRC reconstruction process. During the RRC reconstruction process, the terminal device sends an RRC Reestablishment Complete message to the network device. This message may carry the second information to indicate the first frequency band. After receiving the RRC Reestablishment Complete message, the network device determines that the terminal device has selected the first frequency band based on the frequency band indicated by the second information, and then determines the terminal device's configuration based on the first frequency band.

[0176] For example, the second information can be carried in a MAC CE. Optionally, the MAC CE can be a random access message 3 (Msg3).

[0177] For example, the second information may be carried in (or be) a random access message, which can be used to send the first preamble. This random access message may be Random Access Message 1 (MSG1) or Random Access Message A (MSG A). The first preamble corresponds to a first frequency band, or the first preamble can indicate a first frequency band. Different preambles can correspond to different frequency bands, and the terminal device can indicate the first frequency band through the first preamble corresponding to it. Optionally, before S203, the network device indicates the mapping relationship between the first preamble and the first frequency band to the terminal device, and the terminal device determines the first preamble based on this mapping relationship and the selected first frequency band.

[0178] S202 is an optional step, not a mandatory one, and is therefore represented by a dashed line in Figure 2. Furthermore, if S202 is executed, S202 and S203 can be executed simultaneously; in other words, S202 and S203 can be a single step, for example, S202 can be executed while S203 is being executed.

[0179] S204. The network device determines the third information based on the first frequency band and the capability information of the terminal device. The third information includes carrier configuration information.

[0180] The network device receives the second information, determines the first frequency band, and determines the third information based on the first frequency band and the terminal device's capability information. This third information may include carrier configuration information. For example, the BC capabilities reported by the terminal device based on the capability information may include band A+band B+band C (referred to as BC capability 1) and band A+band B+band D (referred to as BC capability 2). The first frequency band may be band A. The network device can determine that the CA combination is a combination of carrier 1 on band A and carrier 2 on band B. Optionally, the third information may also include other possible configurations, such as measurement configurations.

[0181] Prior to S204, the terminal device could also report UE capability information. After initial registration, the terminal device would report its capability information in response to a network device's capability query message. For example, the terminal device would send capability information to the network device in response to the query message. This capability information included capability parameters or characteristic parameters of one or more capabilities supported by the terminal device. Upon receiving this capability information, the network device would forward it to the core network, where it would store the terminal device's capability information. Subsequently, the network device could obtain the terminal device's capability information from the core network. Alternatively, the terminal device could also complete the reporting of some capabilities via RRC reconfiguration. For example, the terminal device could complete the reporting of measurement gap-related capabilities and DC component transmission location-related capabilities via RRC reconfiguration. The terminal device could report capability information either before or after S202.

[0182] S205. The network device sends third information, and the terminal device receives the third information accordingly.

[0183] Network devices determine carrier configuration information and can send this information to terminal devices by sending third information. This third information can be carried within (or as) an RRC reconfiguration message.

[0184] S204 and S205 are optional steps, not mandatory steps, and are therefore represented by dashed lines in Figure 2. Furthermore, if S204 and S205 are executed, they can be executed simultaneously, or they can be a single step; for example, S204 can be executed while S205 is being executed.

[0185] In the method shown in Figure 2, the terminal device notifies the network device of its selected band (i.e., the first frequency band in this document). The network device then configures relevant parameters for the terminal device based on the first frequency band and the terminal device's capabilities, such as configuring carrier combinations. In this way, the frequency band on which the network device configures parameters for the terminal device is consistent with the frequency band selected by the terminal device. This minimizes the mismatch between the carrier combinations configured by the network device and the terminal device's capabilities, thereby reducing the failure rate of the terminal device accessing the network within the first frequency band, reducing the number of RRC reconstructions initiated by the terminal device, and improving communication efficiency.

[0186] The second method provided in the embodiments of this application is described below.

[0187] In the second communication method, after determining that a cell is available for camping, the terminal device performs a band selection process, notifying the network device of the available bands (i.e., the second frequency band list in this paper). The network device can then select a frequency band (i.e., the second frequency band in this paper) from the second frequency band list and notify the terminal device. Furthermore, the network device configures relevant parameters for the terminal device based on the second frequency band and the terminal device's capabilities, such as configuring carrier combinations. In this way, the frequency band used by the network device to configure parameters for the terminal device is consistent with the frequency band selected by the terminal device, minimizing the mismatch between the carrier combinations configured by the network device and the terminal device's capabilities, thereby reducing the likelihood of the terminal device initiating RRC reconstruction.

[0188] Please refer to Figure 4, which is a flowchart illustrating the second communication method provided in this embodiment. Figure 4 describes the method from the perspective of interaction between network devices and terminal devices. It should be understood that this communication method can also be implemented by other devices, such as a chip or communication device with communication capabilities. Furthermore, the processing performed by a single execution entity can be divided into multiple execution entities, which can be logically and / or physically separated. For example, the processing performed by the network device can be divided into execution by at least one of CU, DU, RU, etc. As shown in Figure 4, the flowchart of the second communication method provided in this embodiment includes the following steps.

[0189] S401. The network device sends the first information. Correspondingly, the terminal device receives the first information.

[0190] For details about S401, please refer to the aforementioned introduction of S201; it will not be repeated here.

[0191] S402. The terminal device determines the second frequency band list based on the first information and the capabilities of the terminal device.

[0192] The second frequency band list belongs to the first frequency band list, or the frequency bands in the second frequency band list belong to the first frequency band list, or the frequency bands in the second frequency band list are a subset of the frequency bands in the first frequency band list. S402 can be replaced by: the terminal device determines the second frequency band list from the first frequency band list, or the terminal device determines the second frequency band list from the first frequency band list based on the capabilities of the terminal device.

[0193] The terminal device receives first information and can determine the available frequency bands based on the first information and the capabilities of the terminal device. For example, the terminal device selects an available frequency band (i.e., a second frequency band list) from a first frequency band list based on the first information and its capabilities. The process by which the terminal device selects an available frequency band from the first frequency band list based on the first information and its capabilities can be referred to the aforementioned UE band selection process, and will not be repeated here. The available frequency bands can also be replaced with candidate frequency bands.

[0194] It should be understood that any frequency band in the second frequency band list satisfies one or more of the following conditions. Optionally, different frequency bands may satisfy different conditions.

[0195] A) The terminal device supports this frequency band;

[0196] The terminal device supports this frequency band, which can also be understood as / replaced as the terminal device including this frequency band in the supported frequency bands reported in the UE capabilities.

[0197] B) The terminal equipment supports at least one transmit power spurious requirement in this frequency band;

[0198] The terminal device receives a first frequency band list from the network device and can obtain at least one transmit power spurious requirement corresponding to the frequency band in the first frequency band list, thereby determining the available frequency band. When the terminal device supports the transmit power spurious requirement corresponding to a certain frequency band, then that frequency band is a usable frequency band for the terminal device.

[0199] C) The terminal device supports an uplink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the uplink BWP bandwidth; and the terminal device supports a downlink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the downlink BWP bandwidth.

[0200] The aforementioned uplink BWP can be the initial uplink BWP or a (e)RedCap UE-specific uplink BWP. The downlink BWP can be the initial downlink BWP or a (e)RedCap UE-specific downlink BWP.

[0201] D) If the first cell indicates that frequency offset is supported, the terminal device supports frequency offset in that frequency band; or the first cell indicates that frequency offset is supported.

[0202] The first cell supports frequency offset, which can be defined as the first cell supporting a 7.5kHz frequency offset. The first cell indicating support for frequency offset can be understood as the first cell indicating that NR uplink transmission is enabled to be offset onto the LTE grid.

[0203] Network devices can use frequencyShift7p5khz to indicate that the first cell supports frequency offset, and this indication can be included in SIB1.

[0204] E) If the first cell indicates support for HD-FDD terminal equipment access, or if the terminal equipment supports FD-FDD on this frequency band;

[0205] Optionally, if the terminal device is (e)RedCap UE, then the terminal device needs to satisfy condition E in this frequency band. Otherwise, if the terminal device is not (e)RedCap UE, then the terminal device does not need to satisfy condition E in this frequency band.

[0206] Optionally, if the frequency band is an FDD band, then the terminal device needs to meet condition E in that frequency band. Otherwise, if the frequency band is not an FDD band (e.g., a TDD band), then the terminal device does not need to meet condition E in that frequency band.

[0207] F) If the terminal device with the first feature is not prohibited from accessing the first cell, the terminal device supports the first feature in this frequency band.

[0208] The first characteristic may include the terminal device supporting one antenna channel or the terminal device supporting two antenna channels. Condition F) can be understood as: if the first cell does not prohibit the access of a terminal device supporting one antenna channel, the terminal device supports one antenna channel in this frequency band; or if the first cell does not prohibit the access of a terminal device supporting two antenna channels, the terminal device supports two antenna channels in this frequency band.

[0209] The first feature can also be other terminal device features, which will not be described in detail here.

[0210] Optionally, the available frequency bands for the terminal device must satisfy all of the conditions A) to F) above. That is, the terminal device selects available frequency bands from the first frequency band list that satisfy conditions A) to F). The terminal device then includes the selected available frequency bands in the second frequency band list.

[0211] The terminal device can determine the second frequency band list from the first frequency band list based on the conditions A) to F) above. The second frequency band list may include one frequency band or multiple frequency bands. The included frequency bands can be indicated by their numbers.

[0212] S403. The terminal device sends the fourth information, and the network device receives the fourth information accordingly.

[0213] The fourth information may indicate a second frequency band list, or it may be used to indicate frequency bands available to the terminal device, or it may be used to indicate frequency bands selectable by the network device. Optionally, the fourth information may indicate a second frequency band list determined by the terminal device according to capabilities / rules, or it may indicate both a second frequency band list and the rules for determining the second frequency band list.

[0214] Optionally, if the first frequency band list includes more than one frequency band (or MFBI), the terminal device sends the fourth information to the network device. If the first frequency band list includes only one frequency band, both the terminal device and the network device use / select that frequency band. Therefore, the terminal device does not need to report its selected frequency band or send the fourth information to the network device, which can save signaling overhead and conserve radio resources.

[0215] The fourth information can be carried in one or more of the following: RRC establishment complete message / RRC establishment complete message, RRC recovery complete message, RRC reconstruction complete message, or MAC CE message. Specifically, refer to the signaling implementation of the fourth information in S203 above, the difference being that the fourth information indicates the second frequency band list, and the network device determines the available frequency bands for the terminal device based on the fourth information.

[0216] S402 is an optional step, not a mandatory step, and is shown as a dashed line in Figure 4. If S420 is executed, S402 and S403 can be executed simultaneously. S402 and S403 can be a single step, for example, S402 can be executed while S403 is being executed.

[0217] S404. The network device sends the fifth message, and the terminal device receives the fifth message accordingly.

[0218] The fifth piece of information may indicate a second frequency band, which belongs to a second frequency band list. The fifth piece of information indicating a second frequency band can be replaced with: the fifth piece of information indicating a frequency band selected by the network device, or the fifth piece of information indicating a frequency band determined by the network device, or the fifth piece of information indicating a frequency band subsequently used by the terminal device, or the fifth piece of information indicating a frequency band used by the primary cell, or the fifth piece of information indicating a frequency band corresponding to the primary cell.

[0219] Prior to S404, network devices could determine the second frequency band from a second frequency band list. The terminal device sends the second frequency band list to the network device via fourth information. Upon receiving this fourth information, the network device can clearly identify the frequency bands available to the terminal device. Therefore, the network device can determine the frequency band (i.e., the second frequency band) for subsequent communication with the terminal device based on the frequency bands in the second frequency band list and the terminal device's capabilities. Optionally, when determining the second frequency band from the second frequency band list, the network device can also consider factors such as the priority of the frequency bands in the second frequency band list on its side. Based on these factors, the second frequency band determined by the network device is both a frequency band supported by the terminal device and a relatively preferred frequency band among those supported by the terminal device, thus improving the flexibility of the network device in selecting frequency bands.

[0220] The network device determines the second frequency band and configures the terminal device based on the second frequency band and the terminal device's capabilities. If the list of second frequency bands includes only one band, the network device designates that band as the second frequency band. If the list of second frequency bands includes multiple bands, the network device can select a second frequency band from these multiple bands based on factors such as the terminal device's capabilities.

[0221] Optionally, if the second frequency band list contains more than one frequency band (at least two frequency bands), the network device sends the fifth information to the terminal device. Alternatively, if both the first and second frequency band lists contain more than one frequency band (at least two frequency bands), the network device sends the fifth information to the terminal device. If either the first or second frequency band list contains only one frequency band, both the terminal device and the network device use / select that frequency band. The network device does not need to indicate its chosen frequency band to the terminal device, thus eliminating the need to send the fifth information, saving signaling overhead and conserving radio resources.

[0222] Optionally, the fifth information is carried in (or is) an RRC reconfiguration message. For example, the terminal device indicates the fourth information to the network device in an RRC connection completion message, an RRC recovery completion message, or an RRC reconstruction completion message, and the network device indicates the fifth information to the terminal device in the first reconfiguration message thereafter.

[0223] S405. The network device determines the sixth information based on the second frequency band and the capability information of the terminal device.

[0224] The network device determines the second frequency band and can determine the sixth information based on the second frequency band and the capability information of the terminal device. This sixth information may include carrier configuration information. Optionally, the sixth information may also include other possible configurations, such as measurement configurations. The network device's determination of the sixth information based on the second frequency band and the terminal device's capabilities can be referenced to the aforementioned determination of the third information based on the first frequency band and the terminal device's capabilities, and will not be repeated here.

[0225] Prior to S405, the terminal device could also report UE capability information. For details on how the terminal device reports its capability information, please refer to the relevant information in S204 above; it will not be repeated here.

[0226] S404 and S405 can be executed simultaneously, or S404 and S405 can be a single step. For example, S404 can be executed while S405 is being executed.

[0227] S406. The network device sends the sixth message, and the terminal device receives the sixth message accordingly.

[0228] Network devices determine carrier configuration information and can send this information to terminal devices by sending a sixth message. This sixth message can be carried within (or as) an RRC reconfiguration message.

[0229] S405 and S406 are optional steps, not mandatory steps, and are therefore represented by dashed lines in Figure 4. Furthermore, if S405 and S406 are executed, they can be executed simultaneously, or they can be a single step; for example, S405 can be executed while S406 is being executed.

[0230] In the method shown in Figure 4, the terminal device indicates the available frequency bands to the network device, which then determines the frequency bands to be used subsequently from the indicated available frequency bands and indicates them to the terminal device. Furthermore, the network device can configure relevant parameters for the terminal device based on the determined frequency bands, such as configuring carrier combinations. In this way, the frequency band on which the network device configures parameters for the terminal device is consistent with the frequency band selected by the terminal device, minimizing mismatches between the carrier combinations configured by the network device and the capabilities of the terminal device, ensuring normal communication between the terminal device and the network device as much as possible, and improving communication efficiency.

[0231] The third method provided in the embodiments of this application is described below.

[0232] In the third communication method, the network device determines the frequency band used by the terminal device (i.e., the third frequency band in this paper) and instructs it to the terminal device, thereby aligning the frequency bands used by the terminal device and the network device. Further, the network device configures relevant parameters for the terminal device based on the third frequency band and the capabilities of the terminal device, such as configuring carrier combinations. In this way, the frequency band on which the network device configures parameters for the terminal device is consistent with the frequency band selected by the terminal device, minimizing the mismatch between the carrier combinations configured by the network device and the capabilities of the terminal device, thereby reducing the need for the terminal device to initiate RRC reconstruction.

[0233] S501, Network equipment determines the third frequency band.

[0234] The third frequency band can be a frequency band from the first frequency band list. A description of the first frequency band list can be found in the aforementioned S201 section, and will not be repeated here. The process by which the network device determines the third frequency band can be similar to the process by which the terminal device selects the first frequency band, and will not be repeated here. Other factors may also be considered in the process by which the network device determines the third frequency band, but these are not constrained here.

[0235] Optionally, prior to S501, the network device may indicate the first frequency band list to the terminal device, as described in the aforementioned S201, which will not be repeated here.

[0236] Optionally, prior to S501, the network device receives UE capability information from the terminal device. For details regarding the reporting of UE capability information by the terminal device, please refer to the relevant description in the aforementioned S204; it will not be repeated here.

[0237] S502, the network device sends the seventh information, and the terminal device receives the seventh information accordingly.

[0238] The seventh information can indicate a third frequency band. The seventh information indicating a third frequency band can be replaced with: the seventh information being used to indicate the frequency band selected by the network device, or the seventh information being used to indicate the frequency band determined by the network device, or the seventh information being used to indicate the frequency band subsequently used by the terminal device, or the seventh information being used to indicate the frequency band used by the primary cell, or the seventh information being used to indicate the frequency band corresponding to the primary cell.

[0239] Optionally, the seventh information is carried in (or is) an RRC reconfiguration message. For example, the seventh information may be included in an information element other than the ReconfigurationWithSync information element. The ReconfigurationWithSync information element can be used to instruct the terminal device to perform a handover.

[0240] Optionally, if the first frequency band list includes more than one frequency band (or MFBI), the network device sends the seventh information to the terminal device. If the first frequency band list includes only one frequency band, both the terminal device and the network device use / select that frequency band, and the network device does not need to send the seventh information to the terminal device, thus saving signaling overhead and conserving radio resources.

[0241] S503. The network device determines the eighth information based on the third frequency band and the capability information of the terminal device.

[0242] The network device determines the third frequency band and can determine the eighth information based on the third frequency band and the capability information of the terminal device. This eighth information may include carrier configuration information. Optionally, the eighth information may also include other possible configurations, such as measurement configurations. The network device's determination of the eighth information based on the third frequency band and the terminal device's capabilities is similar to the aforementioned determination of the third information based on the first frequency band and the terminal device's capabilities, and will not be repeated here.

[0243] S504. The network device sends the eighth message, and the terminal device receives the eighth message accordingly.

[0244] The network device determines the carrier configuration information and can send this information to the terminal device by sending the eighth message. This eighth message can be carried within (or as) an RRC reconfiguration message.

[0245] In Figure 5, step S501 is optional and not mandatory, therefore it is represented by a dashed line. Furthermore, if S501 is executed, S501 and S502 can be executed simultaneously; S501 and S502 can be a single step, for example, S501 can be executed while S502 is being executed. Similarly, steps S503 and S504 are optional and not mandatory, therefore they are represented by dashed lines in Figure 5. Furthermore, if S503 and S504 are executed, they can be executed simultaneously; S503 and S504 can be a single step, for example, S503 can be executed while S504 is being executed.

[0246] The third communication method provided in this application can be applied to scenarios where the terminal device is in a disconnected state or during RRC reconstruction, and can also be used when the terminal device is in a connected state, to dynamically instruct the terminal device to adjust its operating frequency band. For example, when the network device executes S502 for the first time, the third frequency band indicated in the seventh information sent to the terminal device is n77, instructing the terminal device to use n77 as its operating frequency band. When the network device executes S502 for the second time, the third frequency band indicated in the seventh information sent to the terminal device is n78, instructing the terminal device to use n78 as its operating frequency band. After receiving the seventh information sent for the second time, the terminal device switches its operating frequency band from n77 to n78, thereby ensuring that the terminal device and the network device are always aligned in terms of the frequency bands used, reducing the possibility of configuration failures triggering RRC reconstruction. Since this seventh information is not included in the synchronization reconfiguration information element, the network device does not need to instruct the terminal device to switch to adjust its operating frequency band, avoiding frequent switching and service interruptions introduced by adjusting the operating frequency band.

[0247] The methods provided in the embodiments of this application above are described using terminal devices and network devices as examples. In this application, each embodiment can be implemented independently or in combination based on certain inherent connections; in each embodiment, different implementation methods can be implemented in combination or independently. To achieve the functions of the methods provided in the embodiments of this application above, the steps executed by the terminal device can be implemented by the terminal device itself, or by a functional entity including the terminal device, or by different functional entities constituting the terminal device. The steps executed by the network device can be implemented by the network device itself, or by different functional entities constituting the network device, or by a functional entity including the network device. For example, the network device is an access network device, which can be a CU-DU-RU architecture, where the DU can generate first information and the RU can send the first information. To achieve the functions of the methods provided in the embodiments of this application above, the terminal device and network device can include hardware structures and / or software modules, implementing the above functions in the form of hardware structures, software modules, or hardware structures plus software modules. Whether a particular function is executed in the form of hardware structures, software modules, or hardware structures plus software modules depends on the specific application and design constraints of the technical solution.

[0248] Based on the same inventive concept as the method embodiments, this application provides a communication device. The communication device used to implement the above method in the embodiments of this application is described below with reference to the accompanying drawings. The content above can be used in subsequent embodiments, and repeated content will not be repeated.

[0249] Figure 6 is a schematic block diagram of a communication device 600 provided in an embodiment of this application. The communication device 600 can correspondingly implement the functions or steps implemented by the terminal device in the various method embodiments described above. For example, the communication device 600 can be the terminal device in Figure 1; or, the communication device 600 can be a chip (system) in the terminal device; or, the communication device 600 can be a software module of the terminal device. Alternatively, the communication device 600 can correspondingly implement the functions or steps implemented by the network device in the various method embodiments described above. For example, the communication device 600 can be the network device in Figure 1; or, the communication device 600 can be a chip (system) in the network device; or, the communication device 600 can be a software module of the network device. The communication device 600 may include a processing module 610 and a transceiver module 620. Optionally, it may also include a storage module, which can be used to store instructions (code or program) and / or data. The storage module may be, for example, a memory. The processing module 610 and the transceiver module 620 may be coupled to the storage module. For example, the processing module 610 can read instructions (code or program) and / or data from the storage module to implement the corresponding method. When the communication device 600 is a chip in a terminal device, the storage module can be a storage module within the chip, such as a register or cache. Alternatively, the storage module can be a storage module located outside the chip within the terminal device, such as a read-only memory (ROM) or other types of static storage devices capable of storing static information and instructions, such as random access memory (RAM). The aforementioned units can be set independently or partially or completely integrated.

[0250] Processing module 610 may be a processor or controller, such as a CPU, general-purpose processor, DSP, ASIC, FPGA, or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It may implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc. Transceiver module 620 is a transceiver, interface circuit, bus, pin, or other possible communication interface for receiving signals from other devices. For example, when the device is implemented as a chip, transceiver module 620 is an interface circuit for the chip to receive signals from other chips or devices, or an interface circuit for the chip to send signals to other chips or devices.

[0251] In one implementation, the communication device 600 can correspondingly implement the behavior and functions of the terminal device in the above method embodiments. The communication device 600 can be the terminal device itself, a component (e.g., a chip or circuit) within the terminal device, a part of a chip or chipset in the terminal device used to execute the relevant method functions, or a software module in the terminal device capable of implementing the above communication method; there are no limitations. For details, please refer to the relevant content of the foregoing method embodiments, which will not be repeated here.

[0252] For example, the transceiver module 620 is used to receive first information and send second information. The first information indicates a first frequency band list, which indicates the frequency band to which the first cell belongs, and the second information indicates a first frequency band that belongs to the first frequency band list. The processing module 610 is used to determine the first frequency band.

[0253] As an optional implementation, the transceiver module 620 is also used to transmit capability information of the communication device 600 and receive third information, which includes carrier configuration information. The carrier configuration information is related to the first frequency band and the capability information of the communication device 600.

[0254] For example, the transceiver module 620 is used to receive first information, send fourth information, and receive fifth information. The first information is used to indicate a first frequency band list, which indicates the frequency band to which the first cell belongs. The fourth information is used to indicate a second frequency band list, where the frequency bands in the second frequency band list belong to the first frequency band list. The fifth information is used to indicate a second frequency band, which belongs to the second frequency band list. The processing module 610 is used to determine the second frequency band list.

[0255] As an optional implementation, the transceiver module 620 is also used to transmit capability information of the communication device 600 and receive sixth information, which includes carrier configuration information related to the second frequency band and capability information of the communication device 600.

[0256] For example, transceiver module 620 can be used to receive seventh information, which may indicate a third frequency band. Processing module 610 can be used to determine the third frequency band.

[0257] As an optional implementation, the transceiver module 620 is also used to send capability information of the communication device 600 and receive eighth information, which includes carrier configuration information related to the third frequency band and the capability information of the communication device 600.

[0258] In one implementation, the communication device 600 can correspondingly implement the behavior and functions of the network device in the above method embodiments. The communication device 600 can be a network device, a component (e.g., a chip or circuit) within the network device, a part of a chip or chipset in the network device used to execute the relevant method functions, or a software module in the network device capable of implementing the above communication method; there are no limitations. For details, please refer to the relevant content of the foregoing method embodiments, which will not be repeated here.

[0259] For example, the transceiver module 620 is used to receive first information and send second information. The first information indicates a first frequency band list, which indicates the frequency band to which the first cell belongs, and the second information indicates a first frequency band that belongs to the first frequency band list. The processing module 610 is used to determine the first frequency band.

[0260] As an optional implementation, the transceiver module 620 is further configured to receive capability information of the terminal device. The processing module 610 is further configured to determine third information based on the capability information and the first frequency band, the third information including carrier configuration information. The transceiver module 620 is further configured to transmit the third information.

[0261] For example, the transceiver module 620 is used to receive first information, send fourth information, and receive fifth information. The first information is used to indicate a first frequency band list, which indicates the frequency band to which the first cell belongs. The fourth information is used to indicate a second frequency band list, where the frequency bands in the second frequency band list belong to the first frequency band list. The fifth information is used to indicate a second frequency band, which belongs to the second frequency band list. The processing module 610 is used to determine the second frequency band list.

[0262] As an optional implementation, the transceiver module 620 is further configured to receive capability information of the terminal device. The processing module 610 is further configured to determine a second frequency band in the second frequency band list based on the capability information, and to determine sixth information, including carrier configuration information, based on the capability information and the second frequency band. The transceiver module 620 is further configured to transmit the sixth information.

[0263] For example, processing module 610 can be used to determine seventh information, which may indicate a third frequency band. Transceiver module 620 can be used to transmit the seventh information.

[0264] As an optional implementation, the transceiver module 620 is also used to receive capability information of the communication device 600 and send eighth information, which includes carrier configuration information related to the third frequency band and capability information of the communication device 600.

[0265] When the communication device 600 is a chip-based device or circuit, the transceiver module can be an input / output circuit and / or a communication interface; the processing module is an integrated processor, microprocessor, or integrated circuit.

[0266] Figure 7 is a schematic block diagram of a communication device 700 provided in an embodiment of this application. The communication device 700 can be a terminal device or a network device as described in the above embodiments. For example, the communication device 700 can be the terminal device in Figure 1 or a chip (system) within a terminal device. As another example, the communication device 700 can be the network device in Figure 1 or a chip (system) within a network device. In this embodiment, the chip system can be composed of chips or may include chips and other discrete devices. Specific functions can be found in the descriptions of the above method embodiments.

[0267] The communication device 700 includes one or more processors 701, used to implement or support the communication device 700 in implementing the functions of the terminal device or network device in the methods provided in the embodiments of this application. For details, please refer to the detailed description in the method examples, which will not be repeated here. The processor 701 can also be called a processing unit or processing module, and can implement certain control functions to control the communication device 700. The processor 701 can be a general-purpose processor or a dedicated processor, etc. For example, it includes: a baseband processor, a central processing unit, an application processor, a modem processor, a graphics processor, an image signal processor, a digital signal processor, a video codec processor, a controller, a memory, and / or a neural network processor, etc. The baseband processor can be used to process communication protocols and communication data. The central processing unit can be used to control the communication device 700 (e.g., a terminal device or a network device), execute software programs, and / or process data. Different processors can be independent devices or integrated into one or more processors, for example, integrated on one or more application-specific integrated circuits.

[0268] In one design, processor 701 may include program 703 (sometimes referred to as code or instructions) that can be executed on processor 701 to cause communication device 700 to perform the methods described in the embodiments below. In yet another possible design, communication device 700 includes circuitry (not shown in FIG. 7) for implementing the functions of the terminal device or network device in the above embodiments.

[0269] In one design, the communication device 700 may include one or more memories 702 storing a program 704 (sometimes referred to as code or instructions), which can be run on the processor 701 to cause the communication device 700 to perform the methods described in the above method embodiments.

[0270] In one design, the processor 701 and / or memory 702 may include an AI module for implementing AI-related functions. The AI ​​module may be implemented through software, hardware, or a combination of both. For example, the AI ​​module may include a RIC module. For instance, the AI ​​module may be a near real-time RIC or a non-real-time RIC.

[0271] In one possible design, the processor 701 and / or memory 702 may also store data. The processor and memory may be configured separately or integrated together.

[0272] In one possible design, the communication device 700 may further include a communication interface 705. This communication interface 705 may be a transceiver and / or antenna, or a circuit or pin, etc. The transceiver, sometimes also referred to as a transceiver unit, transceiver, transceiver circuit, or simply a transceiver, is used to implement the transmission and reception functions of the communication device 700 via an antenna.

[0273] In one possible design, the communication device 700 may further include one or more of the following components: a wireless communication module, an audio module, an external memory interface, internal memory, a universal serial bus (USB) interface, a power management module, an antenna, a speaker, a microphone, an input / output module, a sensor module, a motor, a camera, or a display screen, etc. It is understood that in some embodiments, the communication device 700 may include more or fewer components, or some components may be integrated, or some components may be separated. These components may be implemented in hardware, software, or a combination of software and hardware.

[0274] The communication device in the above embodiments can be a terminal device or a network device, a circuit, a chip applied in a terminal device or network device, or other combined devices or components having the aforementioned terminal device or network device. When the communication device is a terminal device, the transceiver module can be a transceiver, which may include an antenna and radio frequency circuits, etc., and the processing module can be a processor, such as a CPU. When the communication device is a chip system, the communication device can be an FPGA, a dedicated ASIC, a SoC, a CPU, a network processor (NP), a DSP, a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips. The processing module can be the processor of the chip system. The transceiver module or communication interface can be the input / output interface or interface circuit of the chip system. For example, the interface circuit can be a code / data read / write interface circuit. The interface circuit can be used to receive code instructions (the code instructions are stored in memory and can be read directly from memory or through other devices) and transmit them to the processor; the processor can be used to run the code instructions to execute the methods in the above method embodiments. For example, the interface circuit can also be a signal transmission interface circuit between the communication processor and the transceiver.

[0275] This application also provides a communication system, which includes at least one terminal device and at least one network device. The terminal device is a terminal device used to implement the functions related to the first communication method described above, and the network device is a network device used to implement the functions related to the first communication method described above; or, the terminal device is a terminal device used to implement the functions related to the second communication method described above, and the network device is a network device used to implement the functions related to the second communication method described above; or, the terminal device is a terminal device used to implement the functions related to the third communication method described above, and the network device is a network device used to implement the functions related to the third communication method described above.

[0276] This application also provides a computer-readable storage medium including instructions that, when run on a computer, cause the method executed by the terminal device or network device in the above-described communication method to be executed.

[0277] This application also provides a computer program product, including computer program code, which, when executed, causes the method executed by the terminal device or network device in the above-described communication method to be executed.

[0278] This application provides a chip system including a processor and potentially a memory, for implementing the functions of a terminal device or network device in the aforementioned communication method. The chip system can be composed of chips or may include chips and other discrete components.

[0279] To achieve the functions of the communication devices shown in Figures 6 and 7, this application embodiment also provides a chip, including a processor, for supporting the communication device in implementing the functions involved in the terminal device or network device in the above method embodiments. In one possible design, the chip is connected to a memory or the chip includes a memory for storing necessary computer programs, instructions, and data for the communication device.

[0280] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0281] Those skilled in the art will recognize that the various illustrative logical blocks and steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0282] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0283] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0284] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0285] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the essential contributing part of the technical solution of this application, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, external hard drives, ROM, RAM, magnetic disks, or optical disks.

[0286] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A communication method, characterized in that, The method is applicable to a terminal device or a chip of the terminal device, and the method includes: Receive first information, the first information being used to indicate a first frequency band list, the first frequency band list being used to indicate the frequency band to which the first cell belongs; Send a second message, which indicates a first frequency band, which belongs to the first frequency band list.

2. The method as described in claim 1, characterized in that, The method further includes: The first frequency band is determined from the first frequency band list based on the first information and the capabilities of the terminal device.

3. The method as described in claim 1 or 2, characterized in that, The first frequency band satisfies one or more of the following: The terminal device supports the first frequency band; The terminal device supports at least one transmit power spurious requirement in the first frequency band; The terminal device supports one uplink channel bandwidth, the maximum transmission bandwidth of the uplink channel bandwidth is less than or equal to the carrier bandwidth, and greater than or equal to the uplink bandwidth portion of the BWP bandwidth; The terminal device supports a downlink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the downlink BWP bandwidth. If the first cell indicates support for a 7.5kHz frequency offset, the terminal device supports a 7.5kHz frequency offset in the first frequency band; or if the first cell indicates support for a 7.5kHz frequency offset. When the terminal device that supports half-duplex frequency division duplex (HD-FDD) is accessed in the first cell, or when the terminal device supports full-duplex frequency division duplex (FD-FDD) on the first frequency band; If the terminal device with the first feature is not prohibited from accessing the first cell, the terminal device supports the first feature in the first frequency band. The first feature includes the terminal device supporting one antenna channel or the terminal device supporting two antenna channels.

4. The method as described in claim 3, characterized in that, The first frequency band is the first frequency band in the first frequency band list that satisfies one or more of the conditions.

5. The method according to any one of claims 1-4, characterized in that, The second information is carried in one or more of the following: Radio Resource Control (RRC) establishment complete message; RRC recovery complete message; RRC reconstruction complete message; Media Access Control (MAC) control element CE message; or, A random access message, wherein the random access message is used to send a first preamble, the first preamble corresponding to the first frequency band.

6. The method according to any one of claims 1-5, characterized in that, The method further includes: Send the capability information of the terminal device; Receive third information, the third information including carrier configuration information, the carrier configuration information being related to the first frequency band and the capability information.

7. A communication method, characterized in that, The method is applied to an access network device or a chip of the access network device, and the method includes: Send first information, the first information being used to indicate a first frequency band list, the first frequency band list being used to indicate the frequency band to which the first cell belongs; Receive second information from the terminal device, the second information being used to indicate a first frequency band, the first frequency band belonging to the first frequency band list.

8. The method as described in claim 7, characterized in that, The first frequency band satisfies one or more of the following conditions: The terminal device supports the first frequency band; The terminal device supports at least one transmit power spurious requirement in the first frequency band; The terminal device supports one uplink channel bandwidth, the maximum transmission bandwidth of the uplink channel bandwidth is less than or equal to the carrier bandwidth, and greater than or equal to the uplink bandwidth portion of the BWP bandwidth; The terminal device supports a downlink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the downlink BWP bandwidth. If the first cell indicates support for a 7.5kHz frequency offset, the terminal device supports a 7.5kHz frequency offset in the first frequency band; or if the first cell indicates support for a 7.5kHz frequency offset. When the terminal device that supports half-duplex frequency division duplex (HD-FDD) is accessed in the first cell, or when the terminal device supports full-duplex frequency division duplex (FD-FDD) on the first frequency band; If the terminal device with the first feature is not prohibited from accessing the first cell, the terminal device supports the first feature in the first frequency band. The first feature includes the terminal device supporting one antenna channel or the terminal device supporting two antenna channels.

9. The method as described in claim 8, characterized in that, The first frequency band is the first frequency band in the first frequency band list that satisfies one or more of the conditions.

10. The method according to any one of claims 7-9, characterized in that, The second information is carried in one or more of the following: Radio Resource Control (RRC) establishment complete message; RRC recovery complete message; RRC reconstruction complete message; Media Access Control (MAC) control element CE message; or, A random access message, wherein the random access message is used to send a first preamble, the first preamble corresponding to the first frequency band.

11. The method according to any one of claims 7-10, characterized in that, The method further includes: Receive the capability information of the terminal device; The third information is determined based on the capability information and the first frequency band, and the third information includes carrier configuration information. Send the third message.

12. A communication method, characterized in that, The method is applicable to a terminal device or a chip of the terminal device, and the method includes: Receive first information, the first information being used to indicate a first frequency band list, the first frequency band list being used to indicate the frequency band to which the first cell belongs; Send a fourth message, the fourth message being used to indicate a second frequency band list, wherein the frequency bands in the second frequency band list belong to the first frequency band list; Receive fifth information, which is used to indicate a second frequency band, the second frequency band belonging to the second frequency band list.

13. The method as described in claim 12, characterized in that, The method further includes: The second frequency band list is determined from the first frequency band list based on the first information and the capabilities of the terminal device.

14. The method as described in claim 12 or 13, characterized in that, Any frequency band in the second frequency band list satisfies one or more of the following conditions: The terminal device supports the frequency band; The terminal device supports at least one transmit power spurious requirement in the frequency band; The terminal device supports one uplink channel bandwidth, the maximum transmission bandwidth of the uplink channel bandwidth is less than or equal to the carrier bandwidth, and greater than or equal to the uplink bandwidth portion of the BWP bandwidth; The terminal device supports a downlink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the downlink BWP bandwidth. If the first cell indicates support for a 7.5 kHz frequency offset, the terminal device supports a 7.5 kHz frequency offset in the frequency band; or if the first cell indicates support for a 7.5 kHz frequency offset. When the terminal device that supports half-duplex frequency division duplex (HD-FDD) is accessed in the first cell, or when the terminal device supports full-duplex frequency division duplex (FD-FDD) in the frequency band; If the terminal device with the first feature is not prohibited from accessing the first cell, the terminal device supports the first feature in the frequency band, and the first feature includes the terminal device supporting one antenna channel or the terminal device supporting two antenna channels.

15. The method according to any one of claims 12-14, characterized in that, The fourth information is carried in one or more of the following: Radio Resource Control (RRC) establishment complete message; RRC recovery complete message; RRC reconstruction complete message; or... Media Access Control (MAC) control element CE message.

16. The method according to any one of claims 12-15, characterized in that, The method further includes: Send the capability information of the terminal device; Receive sixth information, which includes carrier configuration information related to the second frequency band and the capability information.

17. A communication method, characterized in that, The method is applied to an access network device or a chip of the access network device, and the method includes: Send first information, the first information being used to indicate a first frequency band list, the first frequency band list being used to indicate the frequency band to which the first cell belongs; Receive fourth information from the terminal device, the fourth information being used to indicate a second frequency band list, wherein the frequency bands in the second frequency band list belong to the first frequency band list; Send a fifth message, which indicates a second frequency band that belongs to the second frequency band list.

18. The method as described in claim 17, characterized in that, Any frequency band in the second frequency band list satisfies one or more of the following conditions: The terminal device supports the frequency band; The terminal device supports at least one transmit power spurious requirement in the frequency band; The terminal device supports one uplink channel bandwidth, the maximum transmission bandwidth of the uplink channel bandwidth is less than or equal to the carrier bandwidth, and greater than or equal to the uplink bandwidth portion of the BWP bandwidth; The terminal device supports a downlink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the downlink BWP bandwidth. If the first cell indicates support for a 7.5 kHz frequency offset, the terminal device supports a 7.5 kHz frequency offset in the frequency band; or if the first cell indicates support for a 7.5 kHz frequency offset. When the terminal device that supports half-duplex frequency division duplex (HD-FDD) is accessed in the first cell, or when the terminal device supports full-duplex frequency division duplex (FD-FDD) in the frequency band; If the terminal device with the first feature is not prohibited from accessing the first cell, the terminal device supports the first feature in the frequency band, and the first feature includes the terminal device supporting one antenna channel or the terminal device supporting two antenna channels.

19. The method as described in claim 17 or 18, characterized in that, The fourth information is carried in one or more of the following: Radio Resource Control (RRC) establishment complete message; RRC recovery complete message; RRC reconstruction complete message; or... Media Access Control (MAC) control element CE message.

20. The method according to any one of claims 17-19, characterized in that, The method further includes: Receive the capability information of the terminal device; The second frequency band in the second frequency band list is determined based on the capability information; The sixth information is determined based on the capability information and the second frequency band, and the sixth information includes carrier configuration information; Send the sixth message.

21. A communication device, characterized in that, include: A transceiver unit is configured to receive first information and send second information; wherein the first information is configured to indicate a first frequency band list, the first frequency band list is configured to indicate the frequency band to which the first cell belongs; the second information is configured to indicate a first frequency band, the first frequency band belonging to the first frequency band list; A processing unit is used to determine the second information.

22. The apparatus as claimed in claim 21, characterized in that, The processing unit is also used for: The first frequency band is determined from the first frequency band list based on the first information and the capabilities of the communication device.

23. The apparatus as claimed in claim 21 or 22, characterized in that, The first frequency band satisfies one or more of the following: The communication device supports the first frequency band; The communication device supports at least one transmit power spurious requirement on the first frequency band; The communication device supports an uplink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the uplink bandwidth portion of the BWP bandwidth. The communication device supports a downlink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the downlink BWP bandwidth; If the first cell indicates support for a 7.5 kHz frequency offset, the communication device supports a 7.5 kHz frequency offset in the first frequency band; or if the first cell indicates support for a 7.5 kHz frequency offset. When the first cell indicates that the communication device supports half-duplex frequency division duplex (HD-FDD) access, or when the communication device supports full-duplex frequency division duplex (FD-FDD) on the first frequency band; If the communication device with the first feature is not prohibited from accessing the first cell, the communication device supports the first feature on the first frequency band, and the first feature includes the communication device supporting one antenna channel or the communication device supporting two antenna channels.

24. The apparatus as claimed in claim 23, characterized in that, The first frequency band is the first frequency band in the first frequency band list that satisfies one or more of the conditions.

25. The apparatus as claimed in any one of claims 21-24, characterized in that, The second information is carried in one or more of the following: Radio Resource Control (RRC) establishment complete message; RRC recovery complete message; RRC reconstruction complete message; Media Access Control (MAC) control element CE message; or, A random access message, wherein the random access message is used to send a first preamble, the first preamble corresponding to the first frequency band.

26. The apparatus as claimed in any one of claims 21-25, characterized in that, The transceiver unit is also used for: Send the capability information of the communication device; Receive third information, the third information including carrier configuration information, the carrier configuration information being related to the first frequency band and the capability information.

27. A communication device, characterized in that, include: The processing unit is configured to determine first information, the first information being used to indicate a first frequency band list, the first frequency band list being used to indicate the frequency band to which the first cell belongs; The transceiver unit is used to send the first information and receive the second information from the terminal device, wherein the second information is used to indicate a first frequency band, and the first frequency band belongs to the first frequency band list.

28. The apparatus as claimed in claim 27, characterized in that, The first frequency band satisfies one or more of the following conditions: The terminal device supports the first frequency band; The terminal device supports at least one transmit power spurious requirement in the first frequency band; The terminal device supports one uplink channel bandwidth, the maximum transmission bandwidth of the uplink channel bandwidth is less than or equal to the carrier bandwidth, and greater than or equal to the uplink bandwidth portion of the BWP bandwidth; The terminal device supports a downlink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the downlink BWP bandwidth. If the first cell indicates support for a 7.5kHz frequency offset, the terminal device supports a 7.5kHz frequency offset in the first frequency band; or if the first cell indicates support for a 7.5kHz frequency offset. When the terminal device that supports half-duplex frequency division duplex (HD-FDD) is accessed in the first cell, or when the terminal device supports full-duplex frequency division duplex (FD-FDD) on the first frequency band; If the terminal device with the first feature is not prohibited from accessing the first cell, the terminal device supports the first feature in the first frequency band. The first feature includes the terminal device supporting one antenna channel or the terminal device supporting two antenna channels.

29. The apparatus as claimed in claim 28, characterized in that, The first frequency band is the first frequency band in the first frequency band list that satisfies one or more of the conditions.

30. The apparatus as claimed in any one of claims 27-29, characterized in that, The second information is carried in one or more of the following: Radio Resource Control (RRC) establishment complete message; RRC recovery complete message; RRC reconstruction complete message; Media Access Control (MAC) control element CE message; or, A random access message, wherein the random access message is used to send a first preamble, the first preamble corresponding to the first frequency band.

31. The apparatus according to any one of claims 27-30, characterized in that, The transceiver unit is also used for: Receive the capability information of the terminal device; The third information is determined based on the capability information and the first frequency band, and the third information includes carrier configuration information. Send the third message.

32. A communication device, characterized in that, include: A transceiver unit is configured to receive first information, send fourth information, and receive fifth information; wherein the first information is configured to indicate a first frequency band list, the first frequency band list being configured to indicate the frequency band to which the first cell belongs; the fourth information is configured to indicate a second frequency band list, the frequency bands in the second frequency band list belonging to the first frequency band list; and the fifth information is configured to indicate a second frequency band, the second frequency band belonging to the second frequency band list. A processing unit is used to determine the fourth information.

33. The apparatus as claimed in claim 32, characterized in that, The processing unit is also used for: The second frequency band list is determined from the first frequency band list based on the first information and the capabilities of the communication device.

34. The apparatus as claimed in claim 32 or 33, characterized in that, Any frequency band in the second frequency band list satisfies one or more of the following conditions: The communication device supports the frequency band; The communication device supports at least one transmit power spurious requirement in the frequency band; The communication device supports an uplink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the uplink bandwidth portion of the BWP bandwidth. The communication device supports a downlink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the downlink BWP bandwidth; If the first cell indicates support for a 7.5 kHz frequency offset, the communication device supports a 7.5 kHz frequency offset in the frequency band; or if the first cell indicates support for a 7.5 kHz frequency offset. When the first cell indicates that the communication device supports half-duplex frequency division duplex (HD-FDD) access, or the communication device supports full-duplex frequency division duplex (FD-FDD) on the frequency band; If the first cell does not prohibit the access of the communication device with the first feature, the communication device supports the first feature on the frequency band, and the first feature includes the communication device supporting one antenna channel or the communication device supporting two antenna channels.

35. The apparatus according to any one of claims 32-34, characterized in that, The fourth information is carried in one or more of the following: Radio Resource Control (RRC) establishment complete message; RRC recovery complete message; RRC reconstruction complete message; or... Media Access Control (MAC) control element CE message.

36. The apparatus according to any one of claims 32-35, characterized in that, The transceiver unit is also used for: Send the capability information of the communication device; Receive sixth information, which includes carrier configuration information related to the second frequency band and the capability information.

37. A communication device, characterized in that, include: The processing unit is configured to determine first information, the first information being used to indicate a first frequency band list, the first frequency band list being used to indicate the frequency band to which the first cell belongs; A transceiver unit is configured to send the first information, receive the fourth information from the terminal device, and send the fifth information; wherein the fourth information is used to indicate a second frequency band list, and the frequency bands in the second frequency band list belong to the first frequency band list; The fifth piece of information is used to indicate the second frequency band, which belongs to the second frequency band list.

38. The apparatus as claimed in claim 37, characterized in that, Any frequency band in the second frequency band list satisfies one or more of the following conditions: The terminal device supports the frequency band; The terminal device supports at least one transmit power spurious requirement in the frequency band; The terminal device supports one uplink channel bandwidth, the maximum transmission bandwidth of the uplink channel bandwidth is less than or equal to the carrier bandwidth, and greater than or equal to the uplink bandwidth portion of the BWP bandwidth; The terminal device supports a downlink channel bandwidth, the maximum transmission bandwidth of which is less than or equal to the carrier bandwidth and greater than or equal to the downlink BWP bandwidth. If the first cell indicates support for a 7.5 kHz frequency offset, the terminal device supports a 7.5 kHz frequency offset in the frequency band; or if the first cell indicates support for a 7.5 kHz frequency offset. When the terminal device that supports half-duplex frequency division duplex (HD-FDD) is accessed in the first cell, or when the terminal device supports full-duplex frequency division duplex (FD-FDD) in the frequency band; If the terminal device with the first feature is not prohibited from accessing the first cell, the terminal device supports the first feature in the frequency band, and the first feature includes the terminal device supporting one antenna channel or the terminal device supporting two antenna channels.

39. The apparatus as claimed in claim 37 or 38, characterized in that, The fourth information is carried in one or more of the following: Radio Resource Control (RRC) establishment complete message; RRC recovery complete message; RRC reconstruction complete message; or... Media Access Control (MAC) control element CE message.

40. The apparatus according to any one of claims 37-39, characterized in that, The transceiver unit is also configured to: receive capability information of the terminal device; The processing unit is further configured to determine the second frequency band in the second frequency band list based on the capability information, and to determine sixth information based on the capability information and the second frequency band, the sixth information including carrier configuration information; The transceiver unit is also used to send the sixth information.

41. A communication device, characterized in that, The communication device includes at least one processor, the at least one processor being configured to cause the method of any one of claims 1-6 to be executed by the communication device, or the at least one processor being configured to cause the communication device to execute the method of any one of claims 7-11, or the at least one processor being configured to cause the communication device to execute the method of any one of claims 12-16, or the at least one processor being configured to cause the communication device to execute the method of any one of claims 17-20.

42. A chip or chip system, characterized in that, The chip or chip system includes: At least one processor and an interface, the at least one processor being configured to call and execute instructions from the interface, wherein when the at least one processor executes the instructions, the method as claimed in any one of claims 1-6 is executed, or the method as claimed in any one of claims 7-11 is executed, or the method as claimed in any one of claims 12-16 is executed, or the method as claimed in any one of claims 17-20 is executed.

43. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store a computer program or instructions that, when executed on a computer, cause the method as described in any one of claims 1-6 to be performed, or the method as described in any one of claims 7-11 to be performed, or the method as described in any one of claims 12-16 to be performed, or the method as described in any one of claims 17-20 to be performed.

44. A computer program product, characterized in that, The computer program product includes a computer program or instructions that, when executed on a computer, cause the method as described in any one of claims 1-6 to be performed, or the method as described in any one of claims 7-11 to be performed, or the method as described in any one of claims 12-16 to be performed, or the method as described in any one of claims 17-20 to be performed.

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