A communication method and device

Abstract

The present application relates to the field of communication technology, and discloses a communication method and device for realizing symmetric uplink and downlink coverage of a cell without increasing the internal complexity of the terminal device. The method comprises: a terminal device receives a first message from a network device, the first message indicates a second cell, the second cell comprises a first downlink carrier and a second uplink carrier, wherein the duplex modes of the frequency band to which the first downlink carrier belongs and the frequency band to which the second uplink carrier belongs are different; the terminal device accesses the second cell.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to a Chinese patent application filed with the Intellectual Property Office of the People's Republic of China on January 22, 2021, with application number 202110086444.1 and invention name “A New Single Carrier / Cell Configuration Method”, the entire contents of which are incorporated by reference in this application. Technical Field

[0003] The embodiments of the present application relate to the field of communication technology, and in particular, to a communication method and device. Background Art

[0004] As users' demand for bandwidth continues to grow, high-frequency bands with larger available bandwidths have become candidate bands for new radio (NR) systems. Due to the fact that the higher the frequency, the greater the signal attenuation, and the fact that the transmission power of network equipment must be higher than the transmission power of terminal equipment, when NR cells are deployed, there will be a problem that the terminal equipment at the edge of the cell can receive the signal of the network equipment, but the network equipment cannot receive the signal of the terminal equipment. That is, there is a problem that the uplink (UL) coverage of the cell is smaller than the downlink (DL) coverage of the cell, and the uplink and downlink coverage of the cell is asymmetric.

[0005] At present, one existing solution to the problem of asymmetric uplink and downlink coverage in a cell is to introduce an additional lower frequency uplink band to send uplink signals in addition to the original high frequency uplink band of the cell. The lower frequency uplink band is the supplementary uplink (SUL) band or the auxiliary uplink band, and the original high frequency uplink band is the normal UL band or the non-SUL band. Since the SUL band has a smaller signal attenuation, the uplink and downlink coverage of the cell can be consistent, achieving symmetric uplink and downlink coverage. However, to supplement the uplink coverage through the SUL band, the terminal device needs to add additional hardware to support the SUL band, such as adding a power amplifier, which will increase the cost and volume of the terminal device and affect the user experience. Summary of the invention

[0006] The embodiments of the present application provide a communication method and device for achieving symmetric uplink and downlink coverage of a cell without increasing the internal complexity of a terminal device.

[0007] In a first aspect, an embodiment of the present application provides a communication method, the method comprising: a terminal device receives a first message from a network device, the first message indicates a first cell and a second cell, the first cell includes a first downlink carrier and a first uplink carrier, the second cell includes the first downlink carrier and a second uplink carrier, wherein the duplex mode of the frequency band to which the first downlink carrier belongs is the same as the duplex mode of the frequency band to which the first uplink carrier belongs, and the duplex mode of the frequency band to which the first downlink carrier belongs is different from the duplex mode of the frequency band to which the second uplink carrier belongs; the terminal device selects the first cell or the second cell for access. Optionally, the first downlink carrier is the same as the frequency band to which the first uplink carrier belongs, and the frequency band to which the second uplink carrier belongs is lower than the frequency band to which the first uplink carrier belongs.

[0008] In an embodiment of the present application, the downlink carrier of the TDD frequency band and the uplink carrier of the lower frequency FDD frequency band can be flexibly combined into an uplink and downlink carrier pair and paired into a new cell, so that the uplink and downlink coverage of the new cell can be equivalent, and there is no need for the terminal device to support the SUL frequency band. The uplink and downlink coverage symmetry of the cell can be achieved without increasing the internal complexity of the terminal device.

[0009] In one possible design, the terminal device selects the first cell or the second cell for access, including: the terminal device obtains the downlink channel quality of the first cell or the second cell; when the downlink channel quality is greater than or equal to a first threshold value, the terminal device selects the first cell for access, and when the downlink channel quality is less than the first threshold value, the terminal device selects the second cell for access.

[0010] In the above design, the terminal device can select a second cell with a larger uplink coverage area to access when it is located in the edge area of ​​the first downlink carrier according to the downlink channel quality of the cell, which is beneficial to ensuring the communication quality of the terminal device.

[0011] In one possible design, the terminal device selects the first cell or the second cell for access, including: the terminal device obtains uplink load information of the first cell and the second cell; when the uplink load of the first cell is less than or equal to the uplink load of the second cell, the terminal device selects the first cell for access, and when the uplink load of the first cell is greater than the uplink load of the second cell, the terminal device selects the second cell for access.

[0012] In the above design, the terminal device can select a cell with a smaller uplink load to access according to the uplink load of the cell, which is conducive to achieving load balancing between the first cell and the second cell.

[0013] In one possible design, the terminal device selects the first cell or the second cell for access, including: when the terminal device supports access from the second cell, the terminal device selects the second cell for access; when the terminal device does not support access from the second cell, the terminal device selects the first cell for access.

[0014] In the above design, the terminal device can select a supported cell to access based on the carrier capabilities it supports, which is beneficial to ensuring the communication quality of the terminal device.

[0015] In one possible design, the method also includes: the terminal device receives a second message from the network device, the second message instructing the terminal device to access the first cell or access the second cell; the terminal device selects the first cell or the second cell for access, including: the terminal device selects the first cell or the second cell for access according to the second message.

[0016] In the above design, the terminal device can select a cell to access according to the instructions of the network device, which is beneficial to ensuring the communication quality of the terminal device.

[0017] In one possible design, the method also includes: the terminal device receives a third message from the network device, the third message includes one or more of a second threshold value, a third threshold value, a fourth threshold value and a fifth threshold value, the second threshold value and the third threshold value are used for the first cell to enable neighbor cell measurement and neighbor cell reselection, and the fourth threshold value and the fifth threshold value are used for the second cell to enable neighbor cell measurement and neighbor cell reselection; the terminal device enables neighbor cell measurement and / or neighbor cell reselection for the first cell or the second cell according to the third message.

[0018] In the above design, the network device can instruct the terminal device to enable the downlink channel quality threshold of neighbor cell measurement and neighbor cell reselection for the first cell and the second cell sharing the same downlink carrier, which is helpful to avoid the terminal device from switching cells in advance or delaying.

[0019] In one possible design, the method also includes: the terminal device receives a fourth message from the network device, the fourth message instructing the terminal device to switch from a current cell to a target cell and a configuration of the target cell, wherein the configuration of the target cell includes a physical cell identifier and / or a low-layer configuration of the target cell, and the instruction for the terminal device to switch from the current cell to the target cell includes instructing the terminal device to switch from the first cell to the second cell, or from the second cell to the first cell; the terminal device switches to the target cell and applies the physical cell identifier and / or the low-layer configuration of the target cell.

[0020] In one possible design, the method also includes: when the configuration of the target cell also includes a cell radio network temporary identifier C-RNTI used by the terminal device in the target cell, the terminal device switches to the target cell and applies the C-RNTI, the physical cell identifier of the target cell and / or the low-layer configuration.

[0021] In the above design, when the terminal device switches between the first cell and the second cell, a simplified switching process can be executed without performing downlink-related downlink synchronization, specific broadcast signal configuration, obtaining the main information block, and resetting the media access control entity. This is beneficial to reducing the complexity of cell switching of the terminal device and reducing the data interruption time caused by cell switching.

[0022] In one possible design, the method also includes: the terminal device determines a common physical cell identifier based on the primary synchronization signal SSS and / or secondary synchronization information PSS of the first downlink carrier; the terminal device determines the physical cell identifier of the first cell and the physical cell identifier of the second cell based on the common physical cell identifier.

[0023] In the above design, the physical cell identifiers of the first cell and the second cell can be indicated by a set of SSS and / or PSS, which is helpful to save signaling overhead.

[0024] In a second aspect, an embodiment of the present application provides a communication method, the method comprising: a terminal device receives a first message from a network device, the first message indicates a second cell, the second cell comprises a first downlink carrier and a second uplink carrier, wherein a frequency band to which the first downlink carrier belongs and a frequency band to which the second uplink carrier belongs have different duplex modes; the terminal device accesses the second cell.

[0025] In an embodiment of the present application, the downlink carrier of the TDD frequency band and the uplink carrier of the lower frequency FDD frequency band can be flexibly combined into an uplink and downlink carrier pair and paired into a new cell, so that the uplink and downlink coverage of the new cell can be equivalent, and there is no need for the terminal device to support the SUL frequency band. The uplink and downlink coverage symmetry of the cell can be achieved without increasing the internal complexity of the terminal device.

[0026] In one possible design, a frequency band to which the second uplink carrier belongs is lower than a frequency band to which the first downlink carrier belongs.

[0027] In a third aspect, an embodiment of the present application provides a communication method, the method comprising: a network device sends a first message to a terminal device, the first message indicating a first cell and a second cell, the first cell comprising a first downlink carrier and a first uplink carrier, the second cell comprising the first downlink carrier and a second uplink carrier, wherein the duplex modes of a frequency band to which the first downlink carrier belongs and the frequency band to which the first uplink carrier belongs are the same, and the duplex modes of a frequency band to which the first downlink carrier belongs and the frequency band to which the second uplink carrier belongs are different.

[0028] In a possible design, the first downlink carrier and the first uplink carrier belong to the same frequency band, and the second uplink carrier belongs to a frequency band lower than the first uplink carrier.

[0029] In one possible design, the method also includes: the network device sends a second message to the terminal device, the second message instructing the terminal device to access the first cell or access the second cell.

[0030] In one possible design, the method also includes: the network device sends a third message to the terminal device, the third message including one or more of a second threshold value, a third threshold value, a fourth threshold value and a fifth threshold value, the second threshold value and the third threshold value are used for the first cell to enable neighbor cell measurement and neighbor cell reselection, and the fourth threshold value and the fifth threshold value are used for the second cell to enable neighbor cell measurement and neighbor cell reselection.

[0031] In one possible design, the method also includes: the network device sends a fourth message to the terminal device, the fourth message instructing the terminal device to switch from a current cell to a target cell and the configuration of the target cell, wherein the configuration of the target cell includes a physical cell identifier and / or a low-layer configuration of the target cell, and the instructing the terminal device to switch from the current cell to the target cell includes instructing the terminal device to switch from the first cell to the second cell, or from the second cell to the first cell.

[0032] In one possible design, when the cell radio network temporary identifier C-RNTI used by the terminal device when switching from the current cell to the target cell changes, the configuration of the target cell also includes the C-RNTI used by the terminal device in the target cell.

[0033] In one possible design, the method also includes: when the duration of sending the fourth message reaches a duration threshold, the network device starts data scheduling in the target cell; or, when the network device receives a scheduling request sent by the terminal device in the target cell, the network device starts data scheduling in the target cell.

[0034] In a fourth aspect, an embodiment of the present application provides a communication method, the method comprising: a network device sends a first message to a terminal device, the first message indicates a second cell, the second cell comprises a first downlink carrier and a second uplink carrier, wherein the duplex modes of a frequency band to which the first downlink carrier belongs and the frequency band to which the second uplink carrier belongs are different.

[0035] In one possible design, a frequency band to which the second uplink carrier belongs is lower than a frequency band to which the first downlink carrier belongs.

[0036] In a fifth aspect, an embodiment of the present application provides a communication device, which has the function of implementing the first aspect or any possible design method of the first aspect, or implementing the second aspect or any possible design method of the second aspect, and the function can be implemented by hardware, or can be implemented by hardware executing corresponding software. The hardware or software includes one or more units (modules) corresponding to the above functions, such as a communication unit and a processing unit.

[0037] In one possible design, the device may be a chip or an integrated circuit.

[0038] In one possible design, the device includes a processor and an interface circuit, wherein the processor is coupled to the interface circuit and is used to implement the first aspect or any possible method in the design of the first aspect, or to implement the function of the second aspect or any possible method in the design of the second aspect. It can be understood that the interface circuit can be a transceiver or an input-output interface. The device may also include a memory, wherein the memory stores a program executable by the processor for implementing the first aspect or any possible method in the design of the first aspect, or to implement the function of the second aspect or any possible method in the design of the second aspect.

[0039] In one possible design, the apparatus may be a terminal device.

[0040] In a sixth aspect, an embodiment of the present application provides a communication device, which has the function of implementing the third aspect or any possible design method of the third aspect, or implementing the fourth aspect or any possible design method of the fourth aspect, and the function can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more units (modules) corresponding to the above functions, such as a communication unit and a processing unit.

[0041] In one possible design, the device may be a chip or an integrated circuit.

[0042] In one possible design, the device includes a processor and an interface circuit, wherein the processor is coupled to the interface circuit and is used to implement the third aspect or any possible method in the design of the third aspect, or to implement the function of the fourth aspect or any possible method in the design of the fourth aspect. It is understandable that the interface circuit can be a transceiver or an input-output interface. The device may also include a memory, wherein the memory stores a program executable by the processor for implementing the third aspect or any possible method in the design of the third aspect, or to implement the function of the fourth aspect or any possible method in the design of the fourth aspect.

[0043] In one possible design, the apparatus may be a network device.

[0044] In the seventh aspect, an embodiment of the present application also provides a communication system, comprising a terminal device and a network device, wherein the terminal device can execute the method described in the first aspect or any possible design of the first aspect, and the network device can execute the method described in the third aspect or any possible design of the third aspect; or, the terminal device can execute the method described in the second aspect or any possible design of the second aspect, and the network device can execute the method described in the fourth aspect or any possible design of the fourth aspect.

[0045] In an eighth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium has a computer program or instruction for executing the method described in the first aspect or any possible design of the first aspect, or executing the method described in the second aspect or any possible design of the second aspect, or executing the method described in the third aspect or any possible design of the third aspect, or executing the method described in the fourth aspect or any possible design of the fourth aspect.

[0046] In the ninth aspect, an embodiment of the present application also provides a computer program product, including a computer program or instructions. When the computer program or instructions are executed, it can implement the method described in the first aspect or any possible design of the first aspect, or implement the method described in the second aspect or any possible design of the second aspect, or implement the method described in the third aspect or any possible design of the third aspect, or implement the method described in the fourth aspect or any possible design of the fourth aspect.

[0047] In the tenth aspect, an embodiment of the present application also provides a chip system, comprising: a processor and an interface, the processor being used to call and run a computer program from the interface, when the processor executes the computer program, it can implement the method described in the above-mentioned first aspect or any possible design of the first aspect, or implement the method described in the above-mentioned second aspect or any possible design of the second aspect, or implement the method described in the above-mentioned third aspect or any possible design of the third aspect, or implement the method described in the above-mentioned fourth aspect or any possible design of the fourth aspect.

[0048] The technical effects that can be achieved from the third to the tenth aspects mentioned above can refer to the technical effects that can be achieved from the first to the second aspects mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A schematic diagram of a network architecture provided for an embodiment of the present application;

[0050] Figure 2 One of the cell coverage diagrams provided in the embodiment of the present application;

[0051] Figure 3 The second schematic diagram of the cell coverage provided in the embodiment of the present application;

[0052] Figure 4 One of the schematic diagrams of the communication method provided in the embodiment of the present application;

[0053] Figure 5 The third schematic diagram of the cell coverage provided in the embodiment of the present application;

[0054] Figure 6 A second schematic diagram of a communication method provided in an embodiment of the present application;

[0055] Figure 7 One of the schematic diagrams of a communication device provided in an embodiment of the present application;

[0056] Figure 8 This is a second schematic diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0057] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as the fifth generation (5G) system or the NR system, or to future communication systems or other similar communication systems, such as the 6G system. Specifically, the architecture of the communication system applied in the embodiments of the present application can be as follows: Figure 1As shown, the communication system includes network equipment and terminal equipment, and the network equipment and terminal equipment can perform uplink communication and downlink communication. Figure 1 The number of terminal devices and network devices in the communication system is shown in .

[0058] Before introducing the embodiments of the present application, some terms in the embodiments of the present application are first explained to facilitate understanding by those skilled in the art.

[0059] 1) A terminal device may be a device with wireless transceiver function, and may also be referred to as a terminal. The terminal device may be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it may also be deployed on the water (such as a ship, etc.); it may also be deployed in the air (such as an airplane, a balloon, and a satellite, etc.). The terminal device may be a user equipment (UE), wherein the UE includes a handheld device, a vehicle-mounted device, a wearable device, or a computing device with wireless communication function. Exemplarily, the UE may be a mobile phone, a tablet computer, or a computer with wireless transceiver function. The terminal device may also be a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in unmanned driving, a wireless terminal in telemedicine, a wireless terminal in a smart grid, a wireless terminal in a smart city, a wireless terminal in a smart home, and the like. In the embodiment of the present application, the device for realizing the function of the terminal device may be a terminal device; it may also be a device capable of supporting the terminal device to realize the function, such as a chip system, which may be installed in the terminal device or used in combination with the terminal device. In the embodiment of the present application, the chip system may be composed of a chip, or may include a chip and other discrete devices. For the convenience of description, in the embodiment of the present application, the device for realizing the function of the terminal device is described as a terminal device.

[0060] 2) A network device may be a device deployed in a radio access network and capable of wirelessly communicating with a terminal device. The network device may be a node in a radio access network, which may also be referred to as a base station, or a radio access network (RAN) node (or device). At present, examples of some network devices are: gNB, transmission reception point (TRP), evolved Node B (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved Node B, or home Node B, HNB), base band unit (BBU), or wireless fidelity (Wifi) access point (AP), etc. In addition, in a network structure, the network device may include a centralized unit (CU) node and / or a distributed unit (DU) node. CU implements some functions of gNB, and DU implements some functions of gNB. For example, CU is responsible for processing non-real-time protocols and services, and implementing the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers. DU is responsible for processing physical layer protocols and real-time services, and implementing the functions of the radio link control (RLC) layer, the media access control (MAC) layer, and the physical (PHY) layer. In an embodiment of the present application, the device for implementing the function of a network device may be a network device; it may also be a device that can support the network device to implement the function, such as a chip system, which may be installed in the network device or used in combination with the network device. For the convenience of description, in an embodiment of the present application, the device for implementing the function of a network device is a network device as an example for description.

[0061] 3) FR1 and FR2. The frequency range of NR includes frequency range 1 (FR1) and frequency range 2 (FR2). FR1 is the commonly referred to 5G Sub-6GHz (below 6GHz) low-frequency band; FR2 is the high-frequency band above 6GHz, such as the 5G millimeter wave band.

[0062] 4) Band: Band is defined in the 3rd Generation Partnership Project (3GPP) protocol, including the uplink frequency range, downlink frequency range, and duplex mode of the band. For example, the uplink frequency range of band n1 is 1920MHz–1980MHz, the downlink frequency range is 2110MHz–2170MHz, and the duplex mode is frequency-division duplex (FDD); the uplink frequency range of band n2 is 1850MHz–1910MHz, the downlink frequency range is 1930MHz–1990MHz, and the duplex mode is FDD; ... the uplink frequency range of band n77 is 3300MHz–4200MHz, the downlink frequency range is 3300MHz–4200MHz, and the duplex mode is time-division duplex (TDD).

[0063] At present, the premise for terminal devices to communicate (such as making calls, browsing the web, using applications (APP), etc.) is to access the network of operators (such as China Mobile, China Unicom, or China Telecom, etc.). The quality of the network accessed by the terminal device directly affects the user's communication experience. Figure 2 As shown, when the terminal device is turned on, it searches for band n77, searches for a usable frequency point in band n77, and accesses the network through the cell at this frequency point. Band n77 is mainly a frequency range near the 3.5GHz spectrum. The 3.5GHz frequency point includes an uplink carrier and a downlink carrier, which is a single carrier (uplink carrier and downlink carrier) when the terminal device works in this cell. Considering that the transmission power of the network equipment is higher than the transmission power of the terminal equipment, there is a problem that the uplink coverage of the cell is smaller than the downlink coverage of the cell.

[0064] In addition, if Figure 3As shown, in addition to the original high-frequency uplink band of the cell, an additional lower-frequency SUL band is introduced to send uplink signals. Although it can solve the problem that the uplink coverage of the cell is smaller than the downlink coverage of the cell, the terminal device needs to add additional hardware to support the SUL band, which will increase the cost and size of the terminal device and affect the user experience.

[0065] The present application aims to provide a communication solution, which achieves symmetric uplink and downlink coverage of a cell by defining a new cell without increasing the internal complexity of the terminal device.

[0066] It should be understood that, in the present application, "at least one" means one or more, and "multiple" means two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. In the text description of the present application, the character " / " generally indicates that the front and back associated objects are an "or" relationship. In addition, unless otherwise specified, the ordinal words such as "first" and "second" mentioned in the embodiments of the present application are used to distinguish multiple objects, and are not used to limit the order, timing, priority or importance of multiple objects, and the description of "first" and "second" does not limit the objects to be different. The various digital numbers involved in the present application are only for the convenience of description and are not used to limit the scope of the embodiments of the present application. The size of the sequence number of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic. In this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" should not be interpreted as being more preferred or more advantageous than other embodiments or designs. The use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete manner for ease of understanding. The embodiments of the present application will be described in detail below in conjunction with the accompanying drawings.

[0067] Figure 4 A schematic diagram of a communication method provided in an embodiment of the present application, the method comprising:

[0068] S401: A network device sends a first message to a terminal device, and the terminal device receives the first message, where the first message indicates a first cell and a second cell, where the first cell includes a first downlink carrier and a first uplink carrier, and where the second cell includes the first downlink carrier and a second uplink carrier.

[0069] The duplex modes of the frequency band to which the first downlink carrier belongs and the frequency band to which the first uplink carrier belongs are the same, and the duplex modes of the frequency band to which the first downlink carrier belongs and the frequency band to which the second uplink carrier belongs are different. Specifically, the frequency band to which the first downlink carrier belongs may be a TDD frequency band, and the frequency band to which the second uplink carrier belongs may be an FDD frequency band; or, the frequency band to which the first downlink carrier belongs may be an FDD frequency band, and the frequency band to which the second uplink carrier belongs may be a TDD frequency band.

[0070] The frequency band is defined in the 3GPP protocol. For the cells in the TDD frequency band, due to the fact that the transmission power of the network equipment is higher than the transmission power of the terminal equipment, there is a problem that the downlink coverage of the cell is greater than the uplink coverage of the cell. In actual applications, the downlink carrier of the 5G millimeter wave is usually equivalent to the coverage of the 6GHz uplink carrier, the 6GHz downlink carrier is equivalent to the coverage of the 2.6GHz uplink carrier, and the 3.5GHz downlink carrier is equivalent to the coverage of the 2.1GHz uplink carrier. In order to achieve symmetric uplink and downlink coverage of the cell, in an embodiment of the present application, on the basis of the cell in the TDD frequency band, the downlink carrier of the cell can be reused, and the downlink carrier of the TDD frequency band and the uplink carrier of the FDD frequency band can be flexibly combined into an uplink and downlink carrier pair to form a new cell. Or it can be understood that the downlink carrier of the cell in the TDD frequency band is reused, and the downlink carrier of the TDD frequency band and the uplink carrier of the FDD frequency band can be flexibly combined into an uplink and downlink carrier pair to form a new cell. The new cell and the existing TDD frequency band cell are deployed on the same network device at the same time, sharing the same downlink carrier of the TDD frequency band.

[0071] As an example, for the first cell (including the first downlink carrier and the second uplink carrier) of the TDD frequency band, the first downlink carrier of the first cell can be reused, and the first downlink carrier and the second uplink carrier of the FDD frequency band can be paired into a new cell, i.e., the second cell. The TDD frequency band is the frequency band corresponding to the duplex mode of TDD, such as band n77; the FDD frequency band is the frequency band corresponding to the duplex mode of FDD, such as band n1.

[0072] Since the signal attenuation is smaller at lower frequencies, in a possible implementation, in order to make the uplink and downlink coverage of the second cell symmetrical, the frequency band to which the second uplink carrier included in the second cell belongs is lower than the frequency band to which the first uplink carrier belongs. Figure 5As shown, the first cell includes a first downlink carrier corresponding to a frequency of 3.5 GHz and a first uplink carrier corresponding to a frequency of 3.5 GHz, the second cell can reuse the first downlink carrier corresponding to a frequency of 3.5 GHz, and the second uplink carrier of the second cell can use an uplink carrier corresponding to a frequency of 2.1 GHz. The frequency band "band n1" to which the second uplink carrier belongs is lower than the frequency band "band n77" to which the first uplink carrier belongs, and the first downlink carrier of the second cell has equivalent coverage to the second uplink carrier, which is basically symmetrical.

[0073] In addition, each existing cell has its own primary synchronization signal (PSS) / secondary synchronization signal (SSS) and system information (SI). Among them, PSS / SSS can be used for downlink synchronization and calculation of the physical-layer cell identity (PCI) of the cell; the system information can be used to broadcast cell-related configuration information, such as the downlink configuration and uplink configuration of the cell. As shown in Table 1, the system information includes the serving cell common configuration information, and the serving cell common configuration information includes DL configuration information (used to indicate downlink configuration information), UL configuration information (used to indicate uplink configuration information), SUL configuration information (used to indicate supplementary uplink configuration information) and other fields. The DL configuration information field is a mandatory field, part of the information in the UL configuration information field is optional, and the SUL configuration information is an optional field, which is optional when the cell has SUL configuration information. For cells belonging to the TDD frequency band, the downlink configuration information of the indicated cells is broadcast in the system information, including the frequency band number and carrier frequency information of the downlink carrier of the TDD frequency band; the uplink configuration information of the indicated cells is broadcast, but it does not need to include the frequency band number and carrier frequency information of the uplink carrier of the TDD frequency band. For cells belonging to the TDD frequency band, there is a default pairing relationship between the uplink carrier and the downlink carrier, that is, the frequency band number and carrier frequency information of the downlink carrier are the same as the frequency band number and carrier frequency information of the uplink carrier. For cells belonging to the FDD frequency band, the downlink configuration information and uplink configuration information of the indicated cells are broadcast in the system information, including the frequency band number and carrier frequency information of the downlink carrier of the FDD frequency band and the frequency band number and carrier frequency information of the uplink carrier of the FDD frequency band, and the downlink carrier of the FDD frequency band is paired with the uplink carrier of the FDD frequency band.

[0074] System Information: DL configuration information (required) UL configuration information (optional) SUL configuration information (optional)

[0075] Table 1

[0076] In an embodiment of the present application, the second cell may be a cell formed by pairing a TDD frequency band downlink carrier and an FDD frequency band uplink carrier. Considering that the second cell and the first cell share the same first downlink carrier, as shown in Table 2, the network device may add a new optional field in the system information used to broadcast the configuration information related to the first cell, such as the UL configuration information 2 field, which is used to indicate the uplink configuration information of the second cell, wherein the uplink configuration information of the second cell includes the frequency band number and / or carrier frequency information of the second uplink carrier.

[0077] System Information: DL configuration information (required) UL configuration information (optional) SUL configuration information (optional) UL configuration information 2 (optional)

[0078] Table 2

[0079] As an example, the network device can send the above-mentioned system information indicating the first cell and the second cell to the terminal device through a first message. The first message can be RRC dedicated signaling, or it can be a message broadcast by the network device in a system information block (SIB) (for example, SIB1).

[0080] S402: The terminal device selects the first cell or the second cell to access.

[0081] Since the first cell and the second cell share the first downlink carrier, for selective access to the cell, the terminal device can select access to the cell based on information such as the uplink coverage of the cell, the uplink load of the cell, and the capabilities of the terminal device itself, which is explained below with reference to specific examples.

[0082] Method 1: The terminal device selects the first cell or the second cell to access based on the downlink channel quality.

[0083] The quality of the first downlink carrier will be affected by the transmission distance, transmission environment, etc., and will show a downward trend as the distance between the terminal device and the network device increases, resulting in the downlink channel quality of the first cell and the second cell decreasing as the distance between the terminal device and the network device increases. Therefore, the terminal device can identify whether the terminal device is located in the central coverage area of ​​the first downlink carrier or the edge coverage area of ​​the first downlink carrier based on the downlink channel quality of the first cell or the second cell, and select the first cell or the second cell for access according to the area where the terminal device is located. Among them, the downlink channel quality can be a measured value of a downlink direction signal or channel of the first cell or the second cell, including but not limited to one or more of reference signal receiving power (reference signal receiving power, RSRP), reference signal receiving quality (reference signal receiving quality, RSRQ), signal to interference plus noise ratio (signal to interference plus noise ratio, SINR), etc.

[0084] In a possible implementation, when selecting the first cell or the second cell for access, the terminal device may measure the downlink channel quality of the first cell or the second cell. When the downlink channel quality is greater than or equal to the first threshold value, the terminal device selects the first cell for access. When the downlink channel quality is less than the first threshold value, the terminal device selects the second cell for access. In addition, it should be understood that when the downlink channel quality is multiple of RSRP, RSRQ, SINR, etc., there will be multiple corresponding first threshold values. It can be that when the downlink channel qualities are all greater than or equal to the corresponding first threshold values, the terminal device determines that the downlink channel quality is greater than the first threshold value; it can also be that when any of the downlink channel qualities is greater than or equal to the corresponding first threshold value, the terminal device determines that the downlink channel quality is greater than the first threshold value.

[0085] Taking the downlink channel quality including RSRP and RSRQ, and the first threshold value including the RSRP threshold value and the RSRQ threshold value as an example, it may be that only when RSRP is greater than or equal to the RSRP threshold value and RSRQ is greater than or equal to the RSRQ threshold value, the terminal device determines that the downlink channel quality is greater than or equal to the first threshold value, otherwise, the terminal device determines that the downlink channel quality is less than the first threshold value; it may also be that when either RSRP is greater than or equal to the RSRP threshold value or RSRQ is greater than or equal to the RSRQ threshold value is met, the terminal device determines that the downlink channel quality is greater than or equal to the first threshold value.

[0086] Among them, the first threshold value can be sent to the terminal device by the network device through broadcast (such as SIB1) or multicast message, or through RRC dedicated signaling, or other RRC configuration signaling, or MAC control element (CE) signaling, or can be pre-configured in the terminal device through a protocol, etc.

[0087] Method 2: The terminal device selects the first cell or the second cell to access based on the uplink load information.

[0088] In a possible implementation, the network device may send the uplink load information of the first cell and the second cell (such as the percentage of uplink bandwidth resource occupancy, etc.) to the terminal device periodically or after sending the first message to the terminal device, and the terminal device may select the cell with the lighter uplink load of the first cell and the second cell for access. For example: when the uplink load of the first cell is less than or equal to the uplink load of the second cell, the terminal device selects the first cell for access, and when the uplink load of the first cell is greater than the uplink load of the second cell, the terminal device may select the second cell for access.

[0089] The uplink load information may be sent from the network device to the terminal device via a broadcast (eg, SIB1) or multicast message, or via RRC dedicated signaling, or other RRC configuration signaling, or MAC CE signaling.

[0090] Method three: The terminal device selects the first cell or the second cell to access based on its own capability information.

[0091] As an example: when the terminal device supports access from the second cell, that is, the terminal device supports the second uplink carrier, the terminal device selects the second cell for access; when the terminal device does not support access from the second cell, the terminal device selects the first cell for access.

[0092] Method 4: The terminal device selects the first cell or the second cell to access according to the instruction of the network device.

[0093] In a possible implementation, the network device may instruct the terminal device to access the corresponding cell by sending a second message to the terminal device to instruct the terminal device to access the first cell or the second cell, based on the uplink load conditions of the first cell and the second cell, or the provisions of the protocol, etc. for the terminal device to select the first cell or the second cell to access. For example, the second message sent by the network device to the terminal device includes 1 bit of indication information, and when the 1 bit is a first value (such as a value of 0), it indicates that the terminal device accesses the first cell or allows the terminal device to access from the first cell, and when it is a second value (such as a value of 1), it indicates that the terminal device accesses the second cell or allows the terminal device to access from the second cell. Alternatively, the second message sent by the network device to the terminal device includes 1 bit of indication information, and when the 1 bit of indication information does not appear, it indicates that the terminal device accesses the first cell or allows the terminal device to access from the first cell, and when the 1 bit of indication information appears, it indicates that the terminal device accesses the second cell or allows the terminal device to access from the second cell.

[0094] The second message may be a message broadcast (eg, SIB1) or multicast by a network device to a terminal device, or may be an RRC dedicated signaling sent by a network device to a terminal device, etc., and this application does not limit this.

[0095] In another possible implementation, the terminal device may be instructed to allow access from the first cell or the second cell by means of protocol pre-configuration or the like, and the terminal device may also directly select the first cell or the second cell for access according to the protocol.

[0096] It should be noted that: when the terminal device resides in a cell, it can not consider which uplink access cell to use, that is, the terminal device resides on the first downlink carrier shared by the first cell and the second cell. When the terminal device needs to access the network to start data communication, the terminal device selects one of the first cell and the second cell (that is, one of the first uplink carrier and the second uplink carrier) to access according to the above rules (such as the uplink coverage of the cell, the uplink load of the cell, the terminal device's own capabilities, etc.). Alternatively, when the terminal device resides in a cell, it is necessary to consider which cell to access the network from later. The terminal device selects one of the first cell and the second cell (that is, one of the first uplink carrier and the second uplink carrier) to reside according to the above rules (such as the uplink coverage of the cell, the uplink load of the cell, the terminal device's own capabilities, etc.). When the terminal device needs to access the network to start data communication, the terminal device accesses from the currently residing cell. At this time, the terminal device selects the first cell or the second cell to access specifically as follows: the terminal device selects the first cell or the second cell to reside, and accesses from the residing cell.

[0097] In addition, since the first cell and the second cell share the first downlink carrier, a set of PSS / SSS is broadcast on the first downlink carrier, and the physical cell identifier of the cell where the terminal device is located is calculated through PSS / SSS. Therefore, the first cell and the second cell will directly calculate the same physical cell identifier through PSS / SSS. In principle, the physical cell identifiers of adjacent cells are different. Therefore, the calculation and use of the physical cell identifier can be processed in the embodiments of the present application.

[0098] Considering that the first cell and the second cell share the first downlink carrier, for physical layer processes, such as the reception of system information and paging messages on the broadcast channel (physical layer behavior of the common part, for terminal devices in idle / inactive state), the transmission / reception of control information on the uplink / downlink control channel (physical layer behavior of the specific part of the terminal device, for terminal devices in connected state), and the transmission / reception of data on the uplink / downlink shared channel (physical layer behavior of the specific part of the terminal device, for terminal devices in connected state), the same physical cell identifier or different physical cell identifiers can work normally, because the uplink can distinguish the two cells (the first cell and the second cell) through different frequencies (or carriers), and the downlink common content does not need to distinguish the two cells, and the specific content can be distinguished by the identifier of the terminal device characteristics; for high-level (above the physical layer) processes, the network device needs to find the context of the terminal device in the connected state through the physical cell identifier of the cell. Therefore, for terminal devices in idle / inactive state, it is not required to identify the different physical cell identifiers corresponding to the first cell and the second cell, and terminal devices in the connected state need to identify the different physical cell identifiers corresponding to the first cell and the second cell.

[0099] In a possible implementation, the physical cell identifier calculated by PSS / SSS can be used as a public physical cell identifier (i.e., a first-level physical cell identifier), and at the same time, physical cell identifiers different from those of the first cell and the second cell can be configured as specific physical cell identifiers (i.e., second-level physical cell identifiers). The physical cell identifier of the first cell is different from that of the second cell, and the physical cell identifier of the first cell or the physical cell identifier of the second cell can be the same as the identifier of the public physical cell. As an example: the public physical cell identifier is PCI 1, the physical cell identifier of the first cell is PCI 2, and the physical cell identifier of the second cell is PCI 3, wherein PCI 1, PCI 2, and PCI 3 can all be different, or PCI 1 can be the same as PCI 2 but different from PCI 3, or PCI 1 can be the same as PCI 3 but different from PCI 2.

[0100] The network device and the terminal device may determine the physical cell identifier of the first cell and the physical cell identifier of the second cell in the following manner:

[0101] Method 1: The network device and the terminal device calculate the physical cell identifier of the first cell and the physical cell identifier of the second cell based on the common physical cell identifier according to the physical cell identifier offset parameter.

[0102] As an example, the physical cell identifier offset parameter can be configured to the terminal device by predefinition through a protocol or the like, or by broadcasting by a network device or the like, and the network device or the terminal device determines the physical cell identifier of the first cell and / or the physical cell identifier of the second cell based on the offset result of the public physical cell identifier by the physical cell identifier offset parameter. For example: the network device and the terminal device may determine the result of an offset of the public physical cell identifier by physical cell identifier offset parameter 1 as the physical cell identifier of the first cell; and determine the result of an offset of the public physical cell identifier by physical cell identifier offset parameter 2 as the physical cell identifier of the second cell. For another example, the network device and the terminal device may determine the result of an offset of the public physical cell identifier by the physical cell identifier offset parameter as the physical cell identifier of the first cell (or the physical cell identifier of the second cell), and the public physical cell identifier as the physical cell identifier of the second cell (or the physical cell identifier of the first cell).

[0103] Method 2: The network device sends the physical cell identifier of the first cell and / or the physical cell identifier of the second cell to the terminal device by broadcasting or other means. For example, the network device sends the physical cell identifier 1 of the first cell and the physical cell identifier 2 of the second cell to the terminal device. For another example, the network device sends the physical cell identifier of the first cell (or the physical cell identifier of the second cell) to the terminal device, and the public physical cell identifier is the physical cell identifier of the second cell (or the physical cell identifier of the first cell).

[0104] Through the first and second methods, a terminal device in an idle state / inactive state or a terminal device in a connected state can identify different physical cell identifiers corresponding to the first cell and the second cell. The communication between the network device and the terminal device can determine the corresponding physical cell identifier according to the cell accessed by the terminal device; the physical layer behavior of a specific part of the terminal device can also be indicated by the network device indication or protocol pre-definition, and / or the physical layer behavior of the public part uses a public physical cell identifier.

[0105] Method three: The network device can send the physical cell identifier of the first cell and / or the physical cell identifier of the second cell to the terminal device in the connected state through RRC dedicated signaling. At this time, the terminal device in the idle state / inactive state cannot identify the different physical cell identifiers corresponding to the first cell and the second cell, and only uses the public physical cell identifier. At the same time, the physical layer behavior of a specific part of the terminal device can also be indicated by network device indication or protocol pre-definition to use the public physical cell identifier or the specific physical cell identifier of the first cell or the second cell. At this time, the physical layer behavior of the public part can only use the public physical cell identifier.

[0106] It should be noted that the physical cell identifier of the first cell and the physical cell identifier of the second cell specifically refer to a specific physical cell identifier corresponding to the first cell and a specific physical cell identifier corresponding to the second cell.

[0107] The uplink coverage of the second cell is greater than the uplink coverage of the first cell. For terminal devices in an idle state / inactive state, if the first cell and the second cell start neighbor cell measurement and neighbor cell reselection based on the same downlink channel quality threshold value, the terminal device may not switch in time in the first cell, or the terminal device may switch in advance in the second cell. In order to solve the above problem, the network device may also send a third message to the terminal device, the third message including one or more of the second threshold value, the third threshold value, the fourth threshold value and the fifth threshold value, the second threshold value is used to start the neighbor cell measurement of the first cell, the third threshold value is used to start the neighbor cell reselection of the first cell, the fourth threshold value is used to start the neighbor cell measurement of the second cell, and the fifth threshold value is used to start the neighbor cell reselection of the second cell. The terminal device starts the neighbor cell measurement and / or neighbor cell reselection of the first cell or the second cell according to the third message. In a possible implementation, the second threshold value is greater than or equal to the third threshold value, the fourth threshold value is greater than or equal to the fifth threshold value, the second threshold value is less than the fourth threshold value, and the third threshold value is less than the fifth threshold value.

[0108] As an example, when the terminal device resides in the first cell or determines to access the network from the first cell, when the downlink channel quality of the first cell is less than or equal to the second threshold value, the terminal device starts measuring the neighboring cells of the first cell, and when the downlink channel quality of the first cell is less than or equal to the third threshold value, the terminal device starts reselecting the neighboring cells of the first cell. When the terminal device resides in the second cell or determines to access the network from the second cell, when the downlink channel quality of the second cell is less than or equal to the fourth threshold value, the terminal device starts measuring the neighboring cells of the second cell, and when the downlink channel quality of the second cell is less than or equal to the fifth threshold value, the terminal device starts reselecting the neighboring cells of the second cell.

[0109] It should be noted that the neighbor cell measurement includes one or more of intra-frequency neighbor cell measurement, inter-frequency neighbor cell measurement, and inter-system (inter-radio access technology, inter-RAT) neighbor cell measurement. For example, the threshold value for enabling neighbor cell measurement may include: one or more of the threshold value for enabling intra-frequency neighbor cell measurement and the threshold value for enabling inter-frequency and inter-system neighbor cell measurement. The neighbor cell reselection includes one or more of intra-frequency neighbor cell reselection, inter-frequency neighbor cell reselection, and inter-system neighbor cell reselection. Specifically, it may include one or more of intra-frequency neighbor cell reselection, high-priority inter-frequency neighbor cell reselection, equal-priority and low-priority inter-frequency neighbor cell reselection, high-priority inter-system neighbor cell reselection, and equal-priority and low-priority inter-system neighbor cell reselection. For example, the threshold value for enabling neighbor cell reselection may include: a threshold value for enabling same-frequency neighbor cell reselection, a threshold value for enabling high-priority inter-frequency and inter-system neighbor cell reselection, and a threshold value for enabling equal-priority and low-priority inter-frequency and inter-system neighbor cell reselection, or one or more of the threshold values.

[0110] Among them, the third message can be a message broadcast (such as SIB1) or multicast by the network device to the terminal device, or it can be an RRC dedicated signaling sent by the network device to the terminal device, etc., which is not limited in this application.

[0111] For cell switching of terminal devices in a connected state, since the triggering of cell switching is configured by the network equipment, no matter whether the terminal device is connected to the first cell or the second cell, the network equipment can determine when the terminal device triggers the cell switching based on factors such as the capability of the terminal device, the uplink coverage of the resident cell, and the uplink load of the resident cell.

[0112] In addition, the handover execution process after the existing cell handover is triggered. The terminal device receives the synchronous reconfiguration (reconfiguration with sync) message sent by the network device, and switches to the target cell according to the configuration in the synchronous reconfiguration message. The process specifically includes the steps: the terminal device applies the physical cell identifier calculated by the target cell, the terminal device performs downlink synchronization in the target cell, the terminal device applies the target cell-specific broadcast signal configuration, the terminal device obtains the master information block (MIB) of the target cell, the terminal device resets the medium access control (MAC) entity, the terminal device applies the new terminal device identifier under the target cell (i.e., the cell radio network temporary identifier (cell-radio network temporary identifier, C-RNTI)), the terminal device applies the low-level configuration (such as the configuration of the main service cell of the main network device and / or the auxiliary network device (spCellConfigCommon)) according to the received configuration message, etc.

[0113] However, for the special case where the terminal device switches from the first cell to the second cell or from the second cell to the first cell, taking into account the particularity that the first downlink carrier remains unchanged, the terminal device may not perform some or all of the downlink-related actions such as downlink synchronization, specific broadcast signal configuration, acquisition of the main information block, and resetting the medium access control entity (clearing the cache and / or performing random access in the target cell), so as to reduce the complexity of the cell switching of the terminal device and shorten the data interruption time caused by the cell switching.

[0114] In a possible implementation, the network device may send a fourth message to the terminal device (the fourth message may be a synchronization reconfiguration message, etc.) to instruct the terminal device to switch from the current cell to the target cell and the configuration of the target cell, wherein instructing the terminal device to switch from the current cell to the target cell includes instructing the terminal device to switch from the first cell to the second cell, or from the second cell to the first cell. After receiving the fourth message sent by the network device, the terminal device switches to the target cell and applies the configuration of the target cell. Specifically, the configuration of the target cell includes a physical cell identifier and / or a low-level configuration. The terminal device applying the configuration of the target cell includes applying the physical cell identifier and / or the low-level configuration of the target cell.

[0115] As an example, when a terminal device switches from a first cell to a second cell, the terminal device uses the physical cell identifier of the second cell and the low-layer configuration to communicate with the network device. For example, the physical cell identifier of the second cell of the terminal device can be used by the network device to obtain context information of the terminal device from other network devices, and the low-layer configuration includes configuration information related to the physical layer process, such as one or more of physical layer resource information, physical layer feedback-related information, power-related information, and decoding-related information, so that the terminal device and the network device can normally send and receive data through these configuration information.

[0116] In addition, when the C-RNTI used by the terminal device after switching from the current cell to the target cell changes, the configuration of the target cell indicated by the fourth message also includes the C-RNTI used by the terminal device in the target cell. The terminal device also applies the C-RNTI used in the target cell when switching to the target cell.

[0117] Among them, for the terminal device to switch between the first cell and the second cell, a simplified switching process is performed, that is, the terminal device does not perform some or all of the downlink-related downlink synchronization, specific broadcast signal configuration, acquisition of the main information block, and resetting the media access control entity, which can be pre-configured by the protocol, or the network device can explicitly or implicitly notify the terminal device. For example: the network device can indicate the terminal device to switch between the first cell and the second cell to perform a simplified switching process by adding a new field to the new RRC signaling or the existing RRC signaling, or it can implicitly instruct the terminal device to switch between the first cell and the second cell to perform a simplified switching process by not carrying downlink-related configuration (such as only carrying uplink frequency information but not carrying downlink frequency information) and other information in the fourth message.

[0118] In another possible implementation, the network device may also send information such as the configuration of the terminal device in the target cell, such as the physical cell identifier and / or low-layer configuration, to the terminal device in advance through RRC signaling, etc. When the terminal device switches between the first cell and the second cell, the fourth message only indicates that the terminal device switches between the first cell and the second cell (from the current cell to the target cell), and the terminal device performs a simplified switching process.

[0119] As an example: the fourth message may be a new RRC message, an RRC reconfiguration message carrying synchronization reconfiguration, MAC layer signaling (such as MAC CE), physical layer signaling (such as downlink control information (DCI)), etc.

[0120] In addition, it takes a certain amount of time for the terminal device to parse the fourth message, and different terminal devices have different capabilities in parsing the fourth message, and the time required is different. Therefore, after the network sends the fourth message to the terminal device, there is a certain period of ambiguity between the network device and the terminal device. During the ambiguity period, the network device is not sure whether the terminal device has successfully parsed the fourth message, that is, it is not sure whether the terminal device is still in the original cell or has successfully switched to the target cell. During this ambiguity period, if the network device is still performing data scheduling in the original cell, the terminal device may have switched to the target cell, so there is data loss; if the network device is performing data scheduling in the target cell, the terminal device may not have switched to the target cell, so there is also data loss. This situation is particularly prominent when the network device does not send the configuration of the terminal device in the target cell to the terminal device in advance.

[0121] To solve the problem of data loss during the ambiguous period, in a possible implementation, the network device does not actively start data scheduling (such as sending or receiving data of the terminal device) after sending the fourth message, and waits for the terminal device to successfully switch to the target cell. When the target cell sends a scheduling request (scheduling request, SR) to the network device to request the network device to send an uplink authorization (UL grant) to the terminal device and send an RRC completion message, the network device determines that the terminal device has successfully switched to the target cell and starts data scheduling in the target cell.

[0122] In another possible implementation, a duration threshold may be preconfigured through a network device indication or protocol, and when the network device sends the fourth message and the terminal device receives the fourth message, both start timing (such as starting a timer), and when the duration threshold is reached (such as the timer times out), it is considered that the terminal device has successfully switched to the target cell, and the network device starts data scheduling in the target cell. The duration threshold may also be reported to the network device by the terminal device according to its own performance.

[0123] The above is mainly described from the perspective of reusing the downlink carrier of the existing cell, flexibly combining the downlink carrier of the TDD frequency band and the uplink carrier of the FDD frequency band into an uplink and downlink carrier pair, and pairing them into a new cell, and the first message indicates two cells on the same downlink carrier. It can be understood that the downlink carrier of the TDD frequency band and the uplink carrier of the FDD frequency band can also be flexibly combined into an uplink and downlink carrier pair, and paired into a new cell, the network equipment directly indicates the new cell to the terminal equipment, and the terminal equipment accesses the new cell.

[0124] Figure 6 A schematic diagram of a communication method provided in an embodiment of the present application, the method comprising:

[0125] S601: A network device sends a first message to a terminal device, and the terminal device receives the first message, where the first message indicates a second cell, and the second cell includes a first downlink carrier and a second uplink carrier.

[0126] The duplex modes of the frequency band to which the first downlink carrier belongs and the frequency band to which the second uplink carrier belongs are different. Specifically, the frequency band to which the first downlink carrier belongs may be a TDD frequency band, and the frequency band to which the second uplink carrier belongs may be an FDD frequency band; or the frequency band to which the first downlink carrier belongs may be an FDD frequency band, and the frequency band to which the second uplink carrier belongs may be a TDD frequency band.

[0127] S602: The terminal device accesses the second cell.

[0128] Frequency bands are defined in the 3GPP protocol. For cells belonging to the TDD frequency band, due to the fact that the transmission power of network equipment is higher than that of terminal equipment, there is a problem that the downlink coverage of the cell is greater than the uplink coverage of the cell. In actual applications, usually the downlink carrier of a 5G millimeter wave is equivalent to the coverage of a 6GHz uplink carrier, the 6GHz downlink carrier is equivalent to the coverage of a 2.6GHz uplink carrier, and the 3.5GHz downlink carrier is equivalent to the coverage of a 2.1GHz uplink carrier. In order to achieve symmetric uplink and downlink coverage of the cell, in an embodiment of the present application, the downlink carrier of the TDD frequency band and the uplink carrier of the FDD frequency band can be flexibly combined into an uplink and downlink carrier pair to form a new cell. Since the lower the frequency, the smaller the signal attenuation, in one possible implementation, in order to make the uplink coverage and downlink coverage of the second cell symmetrical, the frequency band to which the second uplink carrier included in the second cell belongs is lower than the frequency band to which the first uplink carrier belongs, such as Figure 5 The second district in.

[0129] Since the second cell can be a cell formed by pairing a TDD band downlink carrier and an FDD band uplink carrier, it is necessary to first release the originally paired TDD band uplink carrier in the existing system information, and then add a new field to indicate the frequency band number and carrier frequency information of the second uplink carrier of the second cell.

[0130] In one possible implementation, as shown in Table 2, the network device may add a new optional field in the system information, such as the UL configuration information 2 field, which is mandatory when indicating the second cell through the system information, and is used to indicate the uplink configuration information of the second cell, wherein the uplink configuration information of the second cell includes the frequency band number and / or carrier frequency information of the second uplink carrier, and the network device no longer carries information in the existing UL configuration information field and the SUL configuration information field, and the terminal device and the network device both release the pairing relationship between the DL configuration information field and the existing UL configuration information field and the SUL configuration information field, and pair the second uplink carrier and the first downlink carrier configured by the UL configuration information 2 field and the DL configuration information field to form a new cell, namely, the second cell.

[0131] In another possible implementation, as shown in Table 3, the network device can reuse the UL configuration information field in the system information to indicate the uplink configuration information of the second cell, wherein the uplink configuration information of the second cell includes the frequency band number and / or carrier frequency information of the second uplink carrier, and the terminal device and the network device both release the pairing relationship between the DL configuration information field and the existing UL configuration information field and the SUL configuration information field, and pair the second uplink carrier and the first downlink carrier configured by the UL configuration information field and the DL configuration information field to form a new cell, namely, the second cell.

[0132] System Information: DL configuration information (required) UL configuration information (indicates new UL configuration information) SUL configuration information (optional)

[0133] Table 3

[0134] As shown in Table 4 and Table 5, on the basis of Table 2 and Table 3, a release indication domain field may be added to explicitly indicate the release of the pairing relationship between the existing DL configuration information field, the existing UL configuration information field and the SUL configuration information field. When indicating the second cell, the network device indicates through the release indication domain field that the pairing relationship between the existing DL configuration information field, the existing UL configuration information field and the SUL configuration information field of the terminal device is released.

[0135]

[0136]

[0137] Table 4

[0138] System Information: DL configuration information (required) UL configuration information (indicates new UL configuration information) SUL configuration information (optional) Remove indication field (optional)

[0139] Table 5

[0140] In another possible implementation, a new frequency band can also be directly defined through a protocol, etc. The uplink frequency range or downlink frequency range of the original TDD frequency band can be flexibly paired with the downlink frequency range or uplink frequency range of the original FDD frequency band to form a new frequency band. The terminal device works on the new frequency band and uses the new cell paired with the uplink carrier and downlink carrier of the new frequency band. The network device can directly indicate the downlink configuration information and uplink configuration information of the new frequency band through the DL configuration information field and the UL configuration information field in the existing system information, wherein the downlink configuration information of the new frequency band includes the frequency band number and / or carrier frequency information of the downlink carrier of the new frequency band, and the uplink configuration information of the new frequency band includes the carrier frequency information of the uplink carrier of the new frequency band. The frequency band number of the uplink carrier of the new frequency band is the same as the frequency band number of the downlink carrier of the new frequency band, and may be carried in the uplink configuration information or not.

[0141] As an example, the network device may send the above-mentioned system information that can be used to indicate the second cell to the terminal device via a first message, and the first message may be a message broadcast by the network device in the SIB, etc.

[0142] In addition, it should be understood that in the embodiments of the present application, information is indicated through messages, such as indicating the second cell through a first message, and indicating the terminal device to access the first cell or the second cell through a second message. This usually refers to indicating the information content that needs to be indicated through one or more fields in the message, or information carried by one or more information indication fields.

[0143] The above mainly introduces the solution provided by the present application from the perspective of the interaction between the terminal device and the network device. It can be understood that in order to realize the above functions, each network element includes a hardware structure and / or software module (or unit) corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of each example described in the embodiments disclosed in this document, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0144] Figure 7 and Figure 8 The following is a schematic diagram of the structure of possible communication devices provided in the embodiments of the present application. These communication devices can be used to implement the functions of the terminal device or network device in the above method embodiments, and thus can also achieve the beneficial effects of the above method embodiments. In the embodiments of the present application, the communication device can be Figure 4 or Figure 6 The terminal device in Figure 4 or Figure 6 The network device in the embodiment may also be a module (such as a chip) applied to a terminal device or a network device.

[0145] like Figure 7 The communication device 700 may include: a processing unit 702 and a communication unit 703, and may also include a storage unit 701. The communication device 700 is used to implement the above Figure 4 or Figure 6 The functions of the terminal device or the network device in the method embodiment shown in FIG.

[0146] In one possible design, the processing unit 702 is used to implement the corresponding processing function. The communication unit 703 is used to support the communication between the communication device 700 and other network entities. The storage unit 701 is used to store the program code and / or data of the communication device 700. Optionally, the communication unit 703 may include a receiving unit and / or a sending unit, which are respectively used to perform receiving and sending operations.

[0147] When the communication device 700 is used to implement the function of the terminal device in the method embodiment:

[0148] In a possible implementation, the communication unit 703 is configured to receive a first message from a network device, where the first message indicates a first cell and a second cell, where the first cell includes a first downlink carrier and a first uplink carrier, and the second cell includes the first downlink carrier and a second uplink carrier, wherein a frequency band to which the first downlink carrier belongs and a frequency band to which the first uplink carrier belongs have the same duplex mode, and a frequency band to which the first downlink carrier belongs and a frequency band to which the second uplink carrier belongs have different duplex modes;

[0149] The processing unit 702 is configured to select the first cell or the second cell for access.

[0150] In a possible design, the first downlink carrier and the first uplink carrier belong to the same frequency band, and the second uplink carrier belongs to a frequency band lower than the first uplink carrier.

[0151] In one possible design, when the processing unit 702 selects the first cell or the second cell for access, it is specifically used to obtain the downlink channel quality of the first cell or the second cell; when the downlink channel quality is greater than or equal to a first threshold value, the first cell is selected for access; when the downlink channel quality is less than the first threshold value, the second cell is selected for access.

[0152] In one possible design, the first threshold value is indicated or preconfigured by the network device.

[0153] In one possible design, when the processing unit 702 selects the first cell or the second cell for access, it is specifically used to obtain uplink load information of the first cell and the second cell; when the uplink load of the first cell is less than or equal to the uplink load of the second cell, the first cell is selected for access; when the uplink load of the first cell is greater than the uplink load of the second cell, the second cell is selected for access.

[0154] In one possible design, when the processing unit 702 selects the first cell or the second cell for access, it is specifically used to select the second cell for access when access from the second cell is supported, and select the first cell for access when access from the second cell is not supported.

[0155] In one possible design, the communication unit 703 is further configured to receive a second message from the network device, where the second message indicates access to the first cell or access to the second cell;

[0156] When the processing unit 702 selects the first cell or the second cell for access, it is specifically configured to select the first cell or the second cell for access according to the second message.

[0157] In one possible design, the communication unit 703 is also used to receive a third message from a network device, where the third message includes one or more of a second threshold value, a third threshold value, a fourth threshold value and a fifth threshold value, where the second threshold value and the third threshold value are used to enable neighbor cell measurement and neighbor cell reselection for the first cell, and the fourth threshold value and the fifth threshold value are used to enable neighbor cell measurement and neighbor cell reselection for the second cell; the processing unit 702 is also used to enable neighbor cell measurement and / or neighbor cell reselection for the first cell or the second cell according to the third message.

[0158] In one possible design, the communication unit 703 is also used to receive a fourth message from the network device, the fourth message indicating a switch from a current cell to a target cell and a configuration of the target cell, wherein the configuration of the target cell includes a physical cell identifier and / or a low-layer configuration of the target cell, and the indication of the switch from the current cell to the target cell includes an indication of a switch from the first cell to the second cell, or from the second cell to the first cell; the processing unit 702 is also used to switch to the target cell and apply the physical cell identifier and / or the low-layer configuration of the target cell.

[0159] In one possible design, when the configuration of the target cell also includes a cell radio network temporary identifier C-RNTI used in the target cell, the processing unit 702 switches to the target cell and applies the C-RNTI, the physical cell identifier of the target cell and / or the low-layer configuration.

[0160] In one possible design, the processing unit 702 is also used to determine a common physical cell identifier based on the primary synchronization signal SSS and / or secondary synchronization information PSS of the first downlink carrier; and determine the physical cell identifier of the first cell and the physical cell identifier of the second cell based on the common physical cell identifier.

[0161] In another possible implementation, the communication unit 703 is configured to receive a first message from a network device, where the first message indicates a second cell, where the second cell includes a first downlink carrier and a second uplink carrier, wherein a frequency band to which the first downlink carrier belongs and a frequency band to which the second uplink carrier belongs have different duplex modes;

[0162] The processing unit 702 is configured to access the second cell.

[0163] In one possible design, a frequency band to which the second uplink carrier belongs is lower than a frequency band to which the first downlink carrier belongs.

[0164] When the communication device 700 is used to implement the function of the network device in the method embodiment:

[0165] The processing unit 702 is configured to determine a first message, where the first message indicates a first cell and a second cell, where the first cell includes a first downlink carrier and a first uplink carrier, and the second cell includes the first downlink carrier and a second uplink carrier, wherein a frequency band to which the first downlink carrier belongs and a frequency band to which the first uplink carrier belongs have the same duplex mode, and a frequency band to which the first downlink carrier belongs and a frequency band to which the second uplink carrier belongs have different duplex modes;

[0166] The communication unit 703 is used to send the first message to the terminal device.

[0167] In a possible design, the first downlink carrier and the first uplink carrier belong to the same frequency band, and the second uplink carrier belongs to a frequency band lower than the first uplink carrier.

[0168] In a possible design, the communication unit 703 is also used to send a second message to the terminal device, where the second message indicates that the terminal device accesses the first cell or accesses the second cell.

[0169] In one possible design, the communication unit 703 is also used to send a third message to the terminal device, and the third message includes one or more of a second threshold value, a third threshold value, a fourth threshold value and a fifth threshold value, the second threshold value and the third threshold value are used for the first cell to enable neighbor cell measurement and neighbor cell reselection, and the fourth threshold value and the fifth threshold value are used for the second cell to enable neighbor cell measurement and neighbor cell reselection.

[0170] In one possible design, the communication unit 703 is also used to send a fourth message to the terminal device, wherein the fourth message indicates that the terminal device switches from the current cell to the target cell and the configuration of the target cell, wherein the configuration of the target cell includes the physical cell identifier and / or low-layer configuration of the target cell, and the indication that the terminal device switches from the current cell to the target cell includes indicating that the terminal device switches from the first cell to the second cell, or from the second cell to the first cell.

[0171] In one possible design, when the cell radio network temporary identifier C-RNTI used by the terminal device when switching from the current cell to the target cell changes, the configuration of the target cell also includes the C-RNTI used by the terminal device in the target cell.

[0172] In one possible design, the processing unit 702 is also used to start data scheduling in the target cell when the duration of the communication unit 703 sending the fourth message reaches a duration threshold; or to start data scheduling in the target cell when the communication unit 703 receives a scheduling request sent by the terminal device in the target cell.

[0173] In another possible implementation, the processing unit 702 is configured to determine a first message, where the first message indicates a second cell, where the second cell includes a first downlink carrier and a second uplink carrier, wherein a frequency band to which the first downlink carrier belongs and a frequency band to which the second uplink carrier belongs have different duplex modes;

[0174] The communication unit 703 is used to send the first message to the terminal device.

[0175] In one possible design, a frequency band to which the second uplink carrier belongs is lower than a frequency band to which the first downlink carrier belongs.

[0176] For more detailed description of the processing unit 702 and the communication unit 703, please refer to Figure 4 or Figure 6 The relevant description in the method embodiment shown in is directly obtained and will not be repeated here.

[0177] like Figure 8As shown, the communication device 800 includes a processor 810 and an interface circuit 820. The processor 810 and the interface circuit 820 are coupled to each other. It is understood that the interface circuit 820 can be a transceiver or an input-output interface. Optionally, the communication device 800 may also include a memory 830 for storing instructions executed by the processor 810 or storing input data required by the processor 810 to execute instructions or storing data generated after the processor 810 executes instructions.

[0178] When the communication device 800 is used to implement Figure 4 or Figure 6 When the method is shown, the processor 810 is used to implement the function of the processing unit 702, and the interface circuit 820 is used to implement the function of the communication unit 703.

[0179] As another form of this embodiment, a computer-readable storage medium is provided, on which instructions are stored. When the instructions are executed, the communication method applicable to a terminal device or a network device in the above method embodiment can be executed.

[0180] As another form of this embodiment, a computer program product including instructions is provided, and when the instructions are executed, the communication method applicable to a terminal device or a network device in the above method embodiment can be executed.

[0181] As another form of this embodiment, a chip is provided. When the chip is running, it can execute the communication method applicable to a terminal device or a network device in the above method embodiment.

[0182] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0183] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1A device that provides the functions specified in a block or multiple blocks.

[0184] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0185] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0186] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0187] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the embodiments of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A communication method, characterized in that: include: The terminal device receives a first message from a network device, where the first message indicates a first cell and a second cell, where the first cell includes a first downlink carrier and a first uplink carrier, and the second cell includes the first downlink carrier and a second uplink carrier, where a frequency band to which the first downlink carrier belongs has a same duplex mode as a frequency band to which the first uplink carrier belongs, and a frequency band to which the first downlink carrier belongs has a different duplex mode from a frequency band to which the second uplink carrier belongs; The terminal device selects the first cell or the second cell for access; The first downlink carrier and the first uplink carrier belong to the same frequency band, and the second uplink carrier belongs to a frequency band lower than the first uplink carrier.

2. The method according to claim 1, characterized in that The terminal device selects the first cell or the second cell for access, including: The terminal device obtains the downlink channel quality of the first cell or the second cell; When the downlink channel quality is greater than or equal to a first threshold value, the terminal device selects the first cell for access; when the downlink channel quality is less than the first threshold value, the terminal device selects the second cell for access.

3. The method according to claim 2, characterized in that The first threshold value is indicated or pre-configured by the network device.

4. The method according to claim 1, characterized in that The terminal device selects the first cell or the second cell for access, including: The terminal device obtains uplink load information of the first cell and the second cell; When the uplink load of the first cell is less than or equal to the uplink load of the second cell, the terminal device selects the first cell for access; when the uplink load of the first cell is greater than the uplink load of the second cell, the terminal device selects the second cell for access.

5. The method according to claim 1, characterized in that The terminal device selects the first cell or the second cell for access, including: When the terminal device supports access from the second cell, the terminal device selects the second cell for access; when the terminal device does not support access from the second cell, the terminal device selects the first cell for access.

6. The method according to claim 1, characterized in that The method further comprises: The terminal device receives a second message from the network device, where the second message indicates that the terminal device accesses the first cell or the second cell; The terminal device selects the first cell or the second cell for access, including: The terminal device selects the first cell or the second cell to access according to the second message.

7. The method according to any one of claims 1 to 6, characterized in that The method further comprises: The terminal device receives a third message from the network device, where the third message includes one or more of a second threshold value, a third threshold value, a fourth threshold value, and a fifth threshold value, where the second threshold value and the third threshold value are used for the first cell to start neighbor cell measurement and neighbor cell reselection, and the fourth threshold value and the fifth threshold value are used for the second cell to start neighbor cell measurement and neighbor cell reselection; The terminal device starts neighboring cell measurement and / or neighboring cell reselection for the first cell or the second cell according to the third message.

8. The method according to any one of claims 1 to 6, characterized in that The method further comprises: The terminal device receives a fourth message from the network device, the fourth message instructing the terminal device to switch from a current cell to a target cell and a configuration of the target cell, wherein the configuration of the target cell includes a physical cell identifier and / or a low-layer configuration of the target cell, and the instructing the terminal device to switch from the current cell to the target cell includes instructing the terminal device to switch from the first cell to the second cell, or from the second cell to the first cell; The terminal device switches to the target cell and applies the physical cell identifier and / or the low-layer configuration of the target cell.

9. The method according to claim 8, characterized in that The method comprises: When the configuration of the target cell also includes a cell radio network temporary identifier C-RNTI used by the terminal device in the target cell, the terminal device switches to the target cell and applies the C-RNTI, the physical cell identifier of the target cell and / or the low-layer configuration.

10. The method according to any one of claims 1 to 6, characterized in that The method further comprises: The terminal device determines a common physical cell identifier according to a primary synchronization signal SSS and / or secondary synchronization information PSS of the first downlink carrier; The terminal device determines the physical cell identifier of the first cell and the physical cell identifier of the second cell according to the public physical cell identifier.

11. A communication method, characterized in that: include: The network device sends a first message to the terminal device, where the first message indicates a first cell and a second cell, where the first cell includes a first downlink carrier and a first uplink carrier, and the second cell includes the first downlink carrier and a second uplink carrier, where a frequency band to which the first downlink carrier belongs has a same duplex mode as a frequency band to which the first uplink carrier belongs, and a frequency band to which the first downlink carrier belongs has a different duplex mode from a frequency band to which the second uplink carrier belongs; The first downlink carrier and the first uplink carrier belong to the same frequency band, and the second uplink carrier belongs to a frequency band lower than the first uplink carrier.

12. The method according to claim 11, characterized in that The method further comprises: The network device sends a second message to the terminal device, where the second message instructs the terminal device to access the first cell or the second cell.

13. The method according to claim 11 or 12, characterized in that The method further comprises: The network device sends a third message to the terminal device, and the third message includes one or more of a second threshold value, a third threshold value, a fourth threshold value and a fifth threshold value, the second threshold value and the third threshold value are used for the first cell to enable neighbor cell measurement and neighbor cell reselection, and the fourth threshold value and the fifth threshold value are used for the second cell to enable neighbor cell measurement and neighbor cell reselection.

14. The method according to claim 11 or 12, characterized in that: The method further comprises: The network device sends a fourth message to the terminal device, the fourth message instructing the terminal device to switch from a current cell to a target cell and the configuration of the target cell, wherein the configuration of the target cell includes a physical cell identifier and / or a low-layer configuration of the target cell, and the instructing the terminal device to switch from the current cell to the target cell includes instructing the terminal device to switch from the first cell to the second cell, or from the second cell to the first cell.

15. The method according to claim 14, characterized in that When the cell radio network temporary identifier C-RNTI used by the terminal device for switching from the current cell to the target cell changes, the configuration of the target cell also includes the C-RNTI used by the terminal device in the target cell.

16. The method according to claim 14, characterized in that The method further comprises: When the duration of sending the fourth message reaches a duration threshold, the network device starts data scheduling in the target cell; or, When the network device receives the scheduling request sent by the terminal device in the target cell, the network device starts data scheduling in the target cell.

17. A terminal device, characterized in that: include: A communication unit for receiving and sending data; A processing unit, configured to implement the method according to any one of claims 1 to 10 through the communication unit.

18. A network device, characterized in that: include: A communication unit for receiving and sending data; A processing unit, configured to implement the method according to any one of claims 11 to 16 through the communication unit.

19. A terminal device, characterized in that: include: A processor and a memory, the memory storing a computer program, the processor executing the computer program to perform the method according to any one of claims 1 to 10.

20. A network device, characterized in that: include: A processor and a memory, the memory storing a computer program, the processor executing the computer program to perform the method according to any one of claims 11 to 16.

21. A communication system, characterized in that: include: Terminal device, used to implement the method according to any one of claims 1 to 10; A network device, used to implement the method according to any one of claims 11 to 16.

22. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a computer, the computer executes a method applicable to a terminal device as claimed in any one of claims 1 to 10, or executes a method applicable to a network device as claimed in any one of claims 11 to 16.

23. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is run on a computer, the computer is enabled to execute the method as claimed in any one of claims 1 to 10 applicable to a terminal device, or to execute the method as claimed in any one of claims 11 to 16 applicable to a network device.

24. A chip system, characterized in that: The chip system comprises: A processor and an interface, wherein the processor is used to call and run a computer program from the interface, and when the processor executes the computer program, a method applicable to a terminal device as described in any one of claims 1 to 10 is implemented, or a method applicable to a network device as described in any one of claims 11 to 16 is implemented.

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