Communication method and related product

Abstract

Disclosed in the present application are a communication method and a related product. The method comprises: a terminal device detecting a downlink reference signal on a first link; and when it is detected that the signal strength of the downlink reference signal is less than a first threshold value, sending a random access preamble on a second link according to a first sending power, wherein the second link is a link only for transmitting an uplink signal, the first link corresponds to a first network device, and the second link corresponds to a second network device. By using the method in the embodiments of the present application, the terminal device can initiate random access to the second network device on the second link when path loss information of the second link is not obtained, thus improving the possibility of the terminal device discovering a path with a better communication quality in a new scenario.

Description

Communication methods and related products

[0001] This application claims priority to Chinese Patent Application No. 202411516070.2, filed on October 26, 2024, entitled "Communication Method and Related Products", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, and in particular to a communication method and related products. Background Technology

[0003] In existing supplementary uplink (SUL) or super uplink (SUL) technologies, a cell consists of a normal downlink (NDL) carrier, a normal uplink (NUL) carrier in the same frequency band as the NDL, and a SUL carrier in a lower frequency band than the NUL. Existing supplementary uplink technologies are typically co-located, meaning that for a single base station, the uplink frequency band deployed on that base station includes both the NUL and SUL bands.

[0004] The existing fifth generation (the5) th In 5G systems, in addition to existing SUL co-location scheduling, it is desirable to use uplink dense deployment or scheduling to enhance uplink capacity. This uplink dense deployment or scheduling involves placing transmission reception points (TRPs) with only uplink reception (UL reception only) under the macro gNB, thereby creating more and denser uplink transmissions and expanding uplink capacity. This also supplements the uplink transmission at the macro gNB.

[0005] In scenarios with dense uplink deployments, for a TRP that only receives uplink signals, there is no downlink synchronization reference signal being transmitted. The terminal cannot measure the downlink signal based on the TRP's reference signal at the TRP, and therefore cannot directly establish a communication connection with the TRP. Summary of the Invention

[0006] This application provides a communication method and related products, enabling a terminal device to initiate random access to a second network device on a second link when path loss information on the second link is not obtained. This increases the likelihood that the terminal device will discover a path with better communication quality in new scenarios.

[0007] In a first aspect, this application provides a communication method. The method includes: detecting a downlink reference signal on a first link; when the signal strength of the detected downlink reference signal is less than a first threshold, transmitting a random access preamble on a second link at a first transmission power; the second link is a link that only transmits uplink signals, the first link corresponds to a first network device, and the second link corresponds to a second network device.

[0008] The transmission of uplink signals alone can be replaced by the transmission of uplink information alone, wherein the uplink information includes at least one of uplink reference signals, uplink control information, or uplink data information.

[0009] The first approach can be executed by a terminal device or a module (such as a chip system) within the terminal device, or by a logical node, logical module, or software capable of implementing all or part of the terminal device's functions; there are no restrictions on this.

[0010] From a technical perspective, when the terminal device detects that the signal strength of the downlink reference signal is less than a first threshold on the first link, it initiates a random access preamble on the second link at a first transmit power. This method provides a way for the terminal device to initiate random access to the second network device even without obtaining path loss information on the second link. It increases the likelihood that the terminal device will discover a path with better communication quality in new scenarios.

[0011] In one feasible implementation, the method further includes: receiving a random access response from a first network device, the random access response including path loss information of a second link; and transmitting uplink data information on the second link, the transmission power of the uplink data information being determined based on a target received power value and the path loss information, the target received power value being the power value used by the second network device when receiving uplink data information on the second link.

[0012] The target received power value is the power value used by the second network device when receiving uplink data information on the second link. It can also be replaced by: the target received power value is the target detection value or target threshold of the second network device when receiving uplink information on the second link.

[0013] For example, the second network device receives a target power value detection signal on the second link.

[0014] In other words, when the second network device performs uplink signal detection on the second link, the signal strength it can detect corresponds to the target detection value. The signal strength that the second network device can detect on the second link is greater than or equal to the target threshold.

[0015] In one feasible implementation, the method further includes: receiving first information from a first network device, the first information including a target received power value.

[0016] In one feasible implementation, the first information further includes at least one of the following: a first threshold value, a first transmission power, and a RACH resource set, wherein the RACH resource set includes RACH resources for the terminal device to transmit a random access preamble on the second link.

[0017] For example, the first information can be carried in DCI or RRC signaling. The target receive power and information such as the first transmit power, the first threshold value, and / or RACH resource set in the first information can be sent in the same message or in different messages.

[0018] In one feasible implementation, the path loss information is determined based on the signal strength of the random access preamble received by the second network device and the first transmission power.

[0019] Unlike conventional methods where network devices transmit signals at a preset transmission power, and terminal devices calculate path loss information based on received signal strength and the network device's preset transmission power, this embodiment involves the terminal device transmitting signals at a preset first transmission power, while the network device calculates path loss information based on received signal strength and the first transmission power. This enables the determination of path loss information on the second link communicating with the second network device even when the terminal device cannot receive the downlink reference signal transmitted by the second network device, expanding the communication scenarios for the terminal device and ensuring the reliability of the terminal device's access to network services.

[0020] In one feasible implementation, the first transmission power is a preset value.

[0021] In one feasible implementation, the second link is different from the first link, which is a link with downlink reference signal transmission.

[0022] In one feasible implementation, the uplink data information is message 3.

[0023] In one feasible implementation, a random access preamble is transmitted on the second link at a first transmit power, including:

[0024] Send K random access preambles. The transmission power of the K random access preambles is the first transmission power. K is less than or equal to M, where M is the maximum number of random access attempts. K and M are positive integers.

[0025] From a beneficial perspective, setting a maximum number of random access attempts initiated by a terminal device can help control the energy consumption of the terminal device and prevent it from consuming excessive resources to initiate random access on links that cannot be accessed.

[0026] In one feasible implementation, the method further includes: if K equals M and no random access response is received, then transmitting a signal on the first link at a second transmission power, the second transmission power being used by the terminal device for communication transmission on the first link.

[0027] In this embodiment, after the terminal device initiates the maximum number of random access attempts on the second link and fails, it falls back to the first link to continue communication, ensuring that the terminal device can continuously obtain network services.

[0028] In one feasible implementation, the first link includes a first uplink carrier and a second uplink carrier. The method further includes: when the signal strength of the detected downlink reference signal is less than a second threshold and greater than or equal to a first threshold, the terminal device transmits a signal on the first uplink carrier of the first link, where the first threshold is less than the second threshold; and when the signal strength of the detected downlink reference signal is greater than or equal to the second threshold, the terminal device transmits a signal on the second uplink carrier of the first link.

[0029] The second threshold can be defined as the threshold that triggers the UE to select an uplink carrier on the first link.

[0030] Optionally, the second threshold value can be a value agreed upon in the protocol.

[0031] Optionally, the second threshold value can be a value configured by the first network device for the terminal device.

[0032] Specifically, the second threshold value can be configured to the UE via messages such as DCI or RRC signaling. The second threshold value can be configured to the UE in the same message as the first threshold value, or it can be configured to the UE in different messages.

[0033] From a technical perspective, this embodiment provides a method for the terminal device to determine whether to initiate random access based on whether the detected downlink reference signal is less than a first threshold. Furthermore, in the case of supplementary uplink carriers or co-located conventional uplink carriers, the terminal device determines whether to communicate with the second network device on the first link via supplementary uplink carriers or conventional uplink carriers based on whether the detected downlink reference signal is less than a second threshold. This ensures the richness of scenarios for the terminal device to access network devices and the reliability of the communication process.

[0034] In one feasible implementation, the first threshold value is associated with the first synchronization signal block SSB index, where the first SSB is the SSB detected at the current location of the terminal device.

[0035] The first network device corresponds to different SSB indices in different beam coverage directions. Because the signal strength provided by the first network device varies with different beam coverage directions, the threshold value that triggers the terminal device to initiate other path probing also changes with the beam coverage direction of the terminal device. In other words, different SSB indices are associated with different threshold values.

[0036] From a technical perspective, establishing the association between threshold values ​​and SSB indices allows terminal devices, when covered by different beams in different locations, to determine whether to initiate random access based on a first threshold value associated with the SSB index of that beam. This ensures that terminal devices can make more accurate judgments about the access method based on their current location, thereby guaranteeing the reliability of network communication.

[0037] Secondly, this application provides a communication method. The method includes: receiving second information from a second network device, the second information including the signal strength of a random access preamble received by the second network device, wherein the random access preamble is transmitted by a terminal device on a second link at a first transmission power, and the second link is a link that only transmits uplink signals; and sending a random access response to the terminal device, the random access response including path loss information, the path loss information being determined based on the signal strength of the random access preamble received by the second network device and the first transmission power.

[0038] The second approach can be executed by the first network device or a module (such as a chip system) within the first network device, or by a logical node, logical module, or software capable of performing all or part of the functions of the network device; there are no limitations on this.

[0039] The first network device is a network device on the first link. Therefore, the first network device can receive uplink signals and also send downlink signals.

[0040] In one feasible implementation, the method further includes: sending first information to a terminal device, the first information including a target received power value, the target received power value being the power value used by the second network device when receiving uplink data on the second link.

[0041] In one feasible implementation, the first information further includes at least one of the following: a first threshold value, a first transmit power value, and a RACH resource set, wherein the first threshold value is the maximum signal strength that triggers the terminal device to transmit a random access preamble on the second link, and the RACH resource set includes RACH resources for the terminal device to transmit a random access preamble on the second link.

[0042] In one feasible implementation, the second information also includes the RACH resource identifier of the second link.

[0043] For example, the second information sent by the second network device to the first network device includes the RACH resource identifier of the second link. After receiving the RACH resource identifier, the first network device can calculate the radio access network temporary identifier (RA-RNTI) based on the RACH resource, and then determine which UE initiated the random access.

[0044] In one feasible implementation, the first transmission power is a preset value.

[0045] In one feasible implementation, the second link is different from the first link, which is a link with downlink reference signal transmission.

[0046] In one feasible implementation, when the first information includes a first threshold value, the first information includes the association between multiple threshold values ​​and multiple synchronization signal block (SSB) indices, including the association between the first threshold value and the first SSB index.

[0047] Thirdly, this application provides a communication method. The method includes: receiving a random access preamble from a terminal device on a second link, wherein the random access preamble is transmitted by the terminal device at a first transmission power, and the second link is a link that only transmits uplink signals; sending second information to a first network device, the second information including the signal strength of the received random access preamble; and receiving uplink data information from the terminal device on the second link, wherein the transmission power of the uplink data information is determined based on a target received power value and path loss information, wherein the target received power value is the power value used by the second network device when receiving uplink data on the second link, and the path loss information is determined based on the signal strength of the received random access preamble and the first transmission power.

[0048] The third approach can be executed by a second network device or a module (such as a chip system) within the second network device, or by a logical node, logical module, or software capable of performing all or part of the functions of the network device; there are no restrictions on this.

[0049] Optionally, the second network device can only receive uplink signals and cannot send downlink signals.

[0050] In one feasible implementation, the second information also includes the RACH resource identifier corresponding to the second link.

[0051] Fourthly, a communication device is provided, comprising units or modules for performing any of the possible methods described in the first, second, or third aspects above.

[0052] Fifthly, embodiments of this application provide a communication device, the communication device including at least one processor coupled to a memory; wherein the at least one processor is configured to execute a computer program or instructions stored in the memory, such that the methods that may be implemented in any of the first, second, or third aspects described above are executed.

[0053] Sixthly, embodiments of this application provide a communication system, which includes a terminal device, a first network device, and a second network device, wherein the terminal device is used to perform the method described in any one of the first aspects, the first network device is used to perform the method described in any one of the second aspects, and the second network device is used to perform the method described in any one of the third aspects.

[0054] In a seventh aspect, embodiments of this application provide a computer-readable storage medium storing computer instructions that, when executed, cause the computer to perform the method described in any of the above methods.

[0055] Eighthly, embodiments of this application provide a computer program product, the computer program product including: computer program code, which, when executed by a computer, causes the computer to perform the method described in any of the above methods.

[0056] Ninthly, embodiments of this application provide a chip coupled to a memory for reading and executing program instructions in the memory, so that the device in which the chip is located implements the method described in any of the above methods. Attached Figure Description

[0057] The accompanying drawings used in the embodiments of this application are described below.

[0058] Figure 1A shows a wireless communication system architecture provided in an embodiment of this application.

[0059] Figure 1B is a schematic diagram of a dense UL deployment provided in an embodiment of this application.

[0060] Figure 1C is a schematic diagram of a UL capacity enhancement provided in an embodiment of this application.

[0061] Figure 1D is a schematic diagram of a co-location method provided in an embodiment of this application.

[0062] Figure 1E is a schematic diagram of downlink synchronization reference signal transmission in a scenario of dense uplink deployment provided by an embodiment of this application.

[0063] Figure 2A is a flowchart of a communication method provided in an embodiment of this application.

[0064] Figure 2B is a schematic diagram of a multi-link communication system provided in an embodiment of this application.

[0065] Figure 3 is a flowchart of another communication method provided in an embodiment of this application.

[0066] Figure 4 is a flowchart of another communication method of the system in the embodiment of this application.

[0067] Figure 5A is a flowchart of another communication method provided in an embodiment of this application.

[0068] Figure 5B illustrates a multi-link communication system with a SUL carrier provided in an embodiment of this application.

[0069] Figure 6A is a flowchart of another communication method provided in an embodiment of this application.

[0070] Figure 6B illustrates a multi-beam multi-link communication system provided in an embodiment of this application.

[0071] Figure 7 is a schematic diagram of the structure of a communication device provided in an embodiment of this application.

[0072] Figure 8 is a simplified structural diagram of a network device provided in an embodiment of this application.

[0073] Figure 9 is a simplified structural diagram of a UE provided in an embodiment of this application. Detailed Implementation

[0074] The technical solutions in the embodiments of this application will be described below with reference to the accompanying drawings. The terms "system" and "network" in the embodiments of this application can be used interchangeably. Unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship; for example, A / B can represent A or B. "And / or" in this application is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone, where A and B can be singular or plural. Furthermore, in the description of this application, unless otherwise stated, "multiple" refers to two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be one or multiple. Furthermore, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish between network elements and similar items with essentially the same function. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that the terms "first" and "second" are not necessarily different.

[0075] References to "one embodiment" or "some embodiments" in the embodiments described in this application mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0076] Furthermore, in the embodiments of this application, the words "exemplary," "for example," etc., are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design scheme described as "exemplary" in this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the term "exemplary" is intended to present the concept in a concrete manner.

[0077] In the embodiments of this application, the terms "information," "signal," "message," "channel," and "singaling" may sometimes be used interchangeably. It should be noted that, without emphasizing their distinction, their intended meanings are consistent. Similarly, "of," "corresponding (relevant)," and "corresponding" may sometimes be used interchangeably. It should be noted that, without emphasizing their distinction, their intended meanings are consistent. Furthermore, the " / " mentioned in this application can be used to indicate an "or" relationship.

[0078] The following detailed embodiments further illustrate the objectives, technical solutions, and beneficial effects of this application. It should be understood that the following are merely specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made based on the technical solutions of this application should be included within the scope of protection of this application.

[0079] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0080] The system architecture involved in the embodiments of this application is described below.

[0081] Referring to Figure 1A, which illustrates a wireless communication system architecture provided in an embodiment of this application, the wireless communication system may include multiple radio access network (RAN) nodes and at least one terminal. Some RAN nodes only provide uplink receiving functionality, such as transmitting and receiving points (TRPs) 1 and 2 in Figure 1A. Other RAN nodes provide both uplink receiving and downlink transmitting functionality, such as the base station in Figure 1A. Additionally, the cell where the base station is located provides one NUL and one NDL. Alternatively, the cell may also provide at least one SUL. The NUL and NDL operate in the same frequency band, while the SUL and NUL operate in different frequency bands and at a lower frequency. For example, the NUL / NDL operates in the 3.5GHz band, and the SUL operates in the 700MHz band. The TRPs that only provide uplink receiving operate in a different frequency band than the base station. Optionally, TRPs operating in the same frequency band as the base station may also be included. For example, TRP1 operates in the 3.5GHz band, while TRP2 operates in the 4.9GHz band. TRP1 operates on the same frequency band as the base station.

[0082] The terminal involved in the embodiments of this application can also be referred to as a terminal device, UE, etc. A terminal device can be a user-side entity used to receive or transmit signals, such as a mobile phone. Terminal devices can be used to connect people, objects, and machines. Terminal devices can communicate with one or more core networks through network devices. Terminal devices include handheld devices with wireless connectivity, other processing devices connected to a wireless modem, or vehicle-mounted devices. Terminal devices can be portable, pocket-sized, handheld, computer-embedded, or vehicle-mounted mobile devices. Terminal devices can be widely used in various scenarios, such as cellular communication, D2D, V2X, point-to-point (P2P), machine-to-machine (M2M), machine-type communication (MTC), Internet of Things (IoT), virtual reality (VR), augmented reality (AR), industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, drones, robots, remote sensing, passive sensing, positioning, navigation, autonomous delivery and mobility, etc.Examples of terminal devices include: 3GPP standard user equipment (UE), fixed equipment, mobile equipment, handheld devices, wearable devices, cellular phones, smartphones, session initiated protocol (SIP) phones, laptops, personal computers, smart books, vehicles, satellites, global positioning system (GPS) devices, drones, helicopters, aircraft, ships, remote control devices, smart home devices, industrial equipment, personal communication service (PCS) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), wireless network cameras, tablets, handheld computers, mobile internet devices (MIDs), wearable devices such as smartwatches, VR devices, AR devices, wireless terminals in industrial control, terminals in vehicle-to-everything (V2X) systems, wireless terminals in self-driving vehicles, wireless terminals in smart grids, wireless terminals in transportation safety, and smart city applications. Wireless terminals in various scenarios include smart gas pumps, high-speed rail terminals, and smart home terminals such as smart speakers, smart coffee machines, and smart printers. Terminal 120 can be a wireless device in these scenarios or a device for installing on a wireless device, such as a communication module, modem, or chip. Terminal devices can also be called terminals, user equipment (UE), mobile stations (MS), mobile terminals (MT), etc. Terminal devices can also be terminal devices in future wireless communication systems. Terminal devices can be used in dedicated network equipment or general-purpose equipment. The embodiments of this application do not limit the specific technology or device form used in the terminal device.

[0083] In this application, the communication device used to implement the functions of the terminal device can be a terminal device, a terminal device having some of the functions of the aforementioned terminal device, or a device capable of supporting the implementation of the functions of the aforementioned terminal device, such as a chip system. This device can be installed in the terminal device or used in conjunction with the terminal device. In this application, the chip system can be composed of chips or include chips and other discrete components. The technical solutions provided in this application are described using the example of a terminal device or UE as the communication device.

[0084] The RAN node involved in the embodiments of this application may also be referred to as RAN equipment or network element, base station (BS), access point (AP), network equipment, small tower, etc. Base stations can broadly encompass various names such as, or be interchangeable with, those listed below, including: RAN node, NodeB, evolved NodeB (eNB), next-generation NodeB (gNB), access network equipment in an open radio access network (O-RAN), relay station, access point, transmitting and receiving point (TRP), transmitting point (TP), master eNB (MeNB), secondary eNB (SeNB), multi-standard radio (MSR) node, home base station, network controller, access node, radio node, access point (AP), transmission node, transceiver node, building baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), centralized unit (CU), distributed unit (DU), and radio unit (CU). Units (RU), centralized unit control plane (CU-CP) nodes, centralized unit user plane (CU-UP) nodes, positioning nodes, etc. Base stations can be macro base stations, micro base stations, relay nodes, donor nodes, or similar entities, or combinations thereof. Network equipment can also refer to communication modules, modems, or chips installed within the aforementioned equipment or devices. Network equipment can also be mobile switching centers and equipment that performs base station functions in device-to-device (D2D), vehicle-to-everything (V2X), and machine-to-machine (M2M) communications, as well as network-side equipment in future communication systems. Network equipment can support networks using the same or different access technologies. The embodiments of this application do not limit the specific technologies or equipment forms used in the network equipment.

[0085] In some deployments, the network devices mentioned in the embodiments of this application may be devices including CU, DU, or CU and DU, or devices with control plane CU nodes (central unit-control plane (CU-CP)) and user plane CU nodes (central unit-user plane (CU-UP)) and DU nodes. For example, the network devices may include gNB-CU-CP, gNB-CU-UP, and gNB-DU.

[0086] In some deployments, multiple RAN nodes collaborate to assist terminals in achieving wireless access, with different RAN nodes each implementing some of the base station's functions. For example, RAN nodes can be CUs, DUs, CU-CPs, CU-UPs, or RUs. CUs and DUs can be configured separately or included in the same network element, such as a BBU. RUs can be included in radio frequency equipment or radio frequency units, such as RRUs, AAUs, or RRHs.

[0087] In this application, the communication device used to implement the above-mentioned network access functions can be an access network device, a network device with some access network functions, or a device capable of supporting the implementation of access network functions, such as a chip system, hardware circuit, software module, or hardware circuit plus software module. This device can be installed in the access network device or used in conjunction with the access network device. In the method of this application, the example of an access network device being used as the communication device to implement the access network device functions is described.

[0088] It should be understood that the number and type of each device in the communication system shown in Figure 1A are for illustrative purposes only, and this application is not limited thereto. In actual applications, the communication system may include more terminal devices, more access network devices, and other network elements, such as network elements used to implement artificial intelligence functions.

[0089] It is understandable that all or part of the functions implemented by terminal devices and access network devices can be virtualized, that is, implemented through one or more dedicated processors or general-purpose processors and corresponding software modules. Since terminal devices and access network devices involve air interface transmission, the transmit and receive functions of this interface can be implemented in hardware. Optionally, one or more functions of the virtualized terminal devices, access network devices, or network elements used to implement artificial intelligence functions can be implemented by cloud devices, such as cloud devices in over-the-top (OTT) systems.

[0090] The prior art of the embodiments of this application is described below.

[0091] 1. Increased capacity of communication systems

[0092] In carrier aggregation (CA), a cell is defined as a primary cell (Pcell) [DL CC, UL CC] and a secondary cell (SCell) [DL CC, UL CC]. Specifically, a Pcell contains one uplink component carrier (UL CC) and one downlink component carrier (DL CC); an Scell ​​contains one uplink carrier and one downlink carrier. In flexible access technologies, not limited by CA requirements, a cell can contain one downlink carrier and multiple uplink carriers. The UE can flexibly select the uplink carrier within the cell according to service requirements.

[0093] In existing SUL (Supplemental Uplink or Super Uplink) technology, a cell is configured as [B1 NDL, B1 NUL / B0 SUL]. This means it includes (normal) downlink (normal DL, NDL) in band 1 (B1), (normal) uplink (normal UL, NUL) in band B1, and supplemental uplink (SUL) in band 0 (B0). Specifically, NUL and NDL operate on the same frequency band, and the frequency band of SUL is lower than that of B1, where NUL is located. Existing supplemental uplink technology is typically co-located, meaning that for a single base station, the uplink frequency band deployed on that base station includes both the frequency band where NUL is located and the frequency band where SUL is located.

[0094] On the other hand, in order to expand capacity, 5G communication systems use higher carrier frequencies than LTE. These carrier frequencies include the 4.9GHz band, as well as those above 6GHz, such as the 28GHz, 38GHz, or 60GHz bands, to achieve wireless communication with greater bandwidth and higher transmission rates.

[0095] In existing 5G systems, in addition to the existing SUL co-location scheduling, dense UL deployment / scheduling is expected to be used for UL capacity enhancement. This dense UL deployment / scheduling places TRP sites with only uplink reception under the macro base station, thereby forming more and denser uplink transmissions and expanding uplink capacity. This also forms a supplementary uplink transmission to the macro base station's uplink transmission. Refer to Figure 1B, which is a schematic diagram of a dense UL deployment provided by an embodiment of this application. As shown in Figure 1B, a macro base station and TRP sites with only uplink reception are deployed in the cell. Alternatively, refer to Figure 1C, which is a schematic diagram of UL capacity enhancement provided by an embodiment of this application. As shown in Figure 1C, due to the deployment of TRP sites with only uplink reception in Figure 1B, uplink transmission in a cell includes the macro base station's NUL and SUL1, as well as the TRP site's SUL2, achieving UL capacity enhancement for the cell.

[0096] The new higher frequency spectrum of 4.9 GHz or the higher frequency spectrum can be used on TRP. Typically, it can be used in plant area coverage scenarios.

[0097] 2. UL CC's path loss (PL) value

[0098] Path loss refers to the attenuation of a signal during transmission. In existing systems, uplink transmission is typically supplemented by co-location. Specifically, refer to Figure 1D, which is a schematic diagram of a co-location method provided in an embodiment of this application. As shown in Figure 1D, for a macro base station, when uplink capacity expansion is required, the SUL (including SUL1 and SUL3) and NUL are configured as a single cell on the macro base station side. Furthermore, existing standards stipulate that if a UE is configured with two carriers in a cell, one of which is an NUL carrier and the other or several others are SUL carriers, the SUL carrier and the NUL carrier use the same timing advance (TA) offset and PL value.

[0099] In scenarios with dense uplink deployment, for a TRP that only receives uplink signals, there is no downlink synchronization reference signal being transmitted. The UE cannot measure the downlink signal at the TRP based on the TRP's reference signal, as shown in Figure 1E. Therefore, the path loss of the link between the UE and the TRP cannot be directly determined. How the UE knows the path loss for UL transmission when performing uplink transmission under the TRP in scenarios with dense uplink deployment is an issue that needs to be determined.

[0100] 3. Deficiencies of existing technology

[0101] For the scenario of uplink-only reception, the 3rd Generation Partnership Project (3GPP) currently considers the case where a macro base station and a TRP (Telecommunications Protection Unit) that only receives uplink data share the same frequency band. That is, a macro base station covers a TRP site that only receives uplink data, and the macro base station's uplink frequency band is the same as the TRP site's. In this case, since the UE cannot perform downlink measurements on the link of the TRP site that only receives uplink data, it cannot obtain path loss. Therefore, the UE sends a Sounding Reference Signal (SRS). The base station detects the signal strength of the SRS and the signal strength of the TRP site that only receives uplink data (and feeds it back to the base station). The base station then determines the PL offset based on the difference in signal strength between the two and sends it to the UE. Based on this, the UE can obtain path loss information for the link of the TRP site that only receives uplink data. However, existing technology does not consider the scenario where the base station and the TRP site that only receives uplink data do not share the same frequency band, and how to determine the path loss information for the link of the TRP site that only receives uplink data.

[0102] Example 1: Based on the above description, this application provides a communication method. Referring to Figure 2A, which is a flowchart of a communication method provided in an embodiment of this application, the method includes the following steps:

[0103] 201. The terminal equipment detects the downlink reference signal on the first link.

[0104] The first link corresponds to the first network device.

[0105] The method provided in this application embodiment is applied to a multi-link communication system. Referring to Figure 2B, it is a schematic diagram of a multi-link communication system provided in this application embodiment. As shown in Figure 2B, it includes a terminal device (or UE), a first network device (or gNB), and a second network device (or a TRP with only uplink reception). The first link corresponds to the first network device, meaning the UE communicates with the first network device on the first link. The second link corresponds to the second network device, meaning the UE communicates with the second network device (a TRP with only uplink reception, or simply TRP) on the second link. That is, the first link and the second link are different links; the signal transmitting station on both links is the UE, but the signal receiving station on different links is a different network device. Furthermore, UL and DL transmissions can be performed on the first link, while only uplink transmissions can be performed on the second link. In other words, only uplink information is transmitted on the second link. The uplink information includes at least one of uplink reference signals, uplink control information, or uplink data information.

[0106] In addition, the UE can also perform UL transmission with other TRPs on other links. For example, the UE can perform UL transmission with TRP2 on the third link. The process of the UE establishing a communication connection with the second network device through the second link in this embodiment can also be applied to the process of the UE establishing a communication connection on the third link or other links. This will not be elaborated further.

[0107] The UE detects downlink reference signal (DL RS) on the first link. DL RS can be cell-specific reference signal (CRS), demodulation reference signal (DMRS), channel state information reference signal (CSI-RS), etc.

[0108] 202. When the signal strength of the downlink reference signal is detected to be less than the first threshold, the terminal device transmits a random access preamble on the second link at the first transmit power. Correspondingly, the second network device receives the random access preamble on the second link.

[0109] The second link is a link that only transmits uplink signals. The second link corresponds to the second network device.

[0110] When the UE detects that the signal strength of the UL RS on the first link is less than a first threshold value, it considers the communication quality with the first network device to be poor and probes for a TRP with a better signal in the vicinity. The first threshold value is the maximum threshold value that triggers the UE to probe for a path to access the TRP.

[0111] When the detected downlink reference signal strength is less than the first threshold, it can also be understood as when the detected downlink reference signal strength is less than the first threshold. In this application, detection can be understood as measurement.

[0112] The UE probes the TRP path by sending a random access preamble (or initiating random access, sending a random access request, etc.) at a first transmit power on the second link. The second link is the communication link between the UE and the second network device; sending the random access preamble on the second link is equivalent to probing the path to access the second network device.

[0113] The first transmit power is a preset value, or a fixed value. In other words, the first transmit power is not calculated based on the power control formula related to path loss information on the random access channel (RACH) resources, but is a directly obtained value. In this application, the preset value can be pre-defined by the protocol or configured by the network device through signaling. The signaling is radio resource control (RRC) signaling.

[0114] Optionally, the second link corresponds to a RACH resource, which includes a random access preamble sequence and / or a random access occasion.

[0115] During the UE's transmission of the Probe Random Access Preamble (TRP) path, the parameters involved include: first transmit power, first threshold value, and RACH resources. These parameters can be configured by the first network device for the UE, or they can be specified by the protocol or set by default. Alternatively, some parameters can be configured by the first network device for the UE, while others are specified by the protocol or set by default.

[0116] For example, the following situations may be included:

[0117] The first network device configures the first transmit power through the first information, and the protocol agrees on the first threshold value and RACH resources; or

[0118] The first network device configures the first transmit power and the first threshold value through the first information, and the protocol specifies RACH resources; or

[0119] The first network device configures the first transmit power, the first threshold value, and RACH resources through the first information; or

[0120] The protocol specifies the first transmit power, the first threshold value, and RACH resources.

[0121] Optionally, the first threshold value configured in the first network device is related to the first transmit power. That is, the UE will only transmit the random access preamble at the first transmit power if it detects that the signal strength of the DL RS is less than the first threshold value.

[0122] Optionally, the first threshold value, the first transmit power, and the RACH resource configured in the first network device are correlated. That is, the UE will only transmit the random access preamble on the RACH resource at the first transmit power if it detects that the signal strength of the LRS is less than the first threshold value.

[0123] The first piece of information can be carried in downlink control information (DCI) or RRC signaling messages. Alternatively, the first piece of information used to configure different information can be carried in different messages. For example, the first transmit power can be carried in the DCI, and the first threshold value can be carried in the RRC signaling.

[0124] Additionally, the first network device may have configured a RACH resource set for the UE, including RACH resources corresponding to the second link. This resource set includes a pool of random access preamble sequences and / or packet random access timings.

[0125] As can be seen, in this embodiment, when the terminal device detects that the signal strength of the downlink reference signal is less than a first threshold on the first link, it initiates a random access preamble on the second link according to the first transmission power. This method provides a way for the terminal device to initiate random access to the second network device when it has not obtained path loss information on the second link. This increases the possibility of the terminal device discovering a path with better communication quality in new scenarios.

[0126] Optionally, the first link and the second link do not share the same frequency band.

[0127] For example, if the first link and the second link do not share a frequency band, the path loss on the first link differs significantly from that on the second link. Furthermore, the random access preamble sent by the UE according to the path loss on the first link cannot guarantee that the second network device on the second link will receive it. Therefore, the UE needs to send a message to the second network device on the second link based on the first transmit power. The first transmit power is correlated with the RACH resources of the second link, ensuring that the probability of the random access preamble sent by the UE on the second link according to the first transmit power being received by the second network device is increased. In other words, this method improves the possibility that the network device can access a second network device that only has uplink reception capabilities in the new scenario.

[0128] Example 2:

[0129] The above embodiment one describes the process of a terminal device initiating random access on a second link. Furthermore, the terminal device can access a second network device on the second link and achieve communication with the second network device.

[0130] For details, please refer to Figure 3, which is a flowchart of another communication method provided in an embodiment of this application. As shown in Figure 3, the method includes the following steps:

[0131] 301. The terminal equipment detects the downlink reference signal on the first link.

[0132] The first link corresponds to the first network device.

[0133] 302. When the signal strength of the downlink reference signal is detected to be less than the first threshold, the terminal device transmits a random access preamble on the second link at the first transmit power. Correspondingly, the second network device receives the random access preamble on the second link.

[0134] The second link is a link that only transmits uplink signals. The second link corresponds to the second network device.

[0135] The descriptions of steps 301 and 302 are the same as those of steps 201 and 202 in the foregoing embodiments, and will not be repeated here.

[0136] 303. The second network device sends second information to the first network device, the second information including the signal strength of the received random access preamble. Correspondingly, the first network device receives the second information.

[0137] The second network device sends the signal strength of the received random access preamble to the first network device via second information.

[0138] For the terminal device, random access preambles can be transmitted on multiple RACH resources. Therefore, other network devices on the links corresponding to these multiple RACH resources can also receive the random access preambles and send their signal strengths to the first network device. Correspondingly, the first network device can receive the signal strengths of random access preambles transmitted by multiple network devices that only have uplink reception capabilities.

[0139] For example, the signal strength of the random access preamble received by the first network device on the second link from the second network device is A1 dBm;

[0140] The first network device receives a signal strength of A2 dBm for the random access preamble from the third network device on the third link.

[0141] The first network device receives a signal strength of A3 dBm for the random access preamble from the fourth network device on the fourth link.

[0142] Among them, the third network device and the fourth network device are both network devices that only receive uplink signals, and the third link and the fourth link only transmit uplink signals.

[0143] Optionally, when the second network device sends the second information to the first network device, it may also send the RACH resource identifier corresponding to the second link to the first network device. After receiving the RACH resource identifier, the first network device can calculate the radio access network temporary identifier (RA-RNTI) based on the RACH resource, and then determine which UE initiated the random access.

[0144] 304. The first network device sends a random access response to the terminal device. The random access response includes path loss information, which is determined based on the signal strength of the random access preamble received by the second network device and the first transmission power. Correspondingly, the terminal device receives the random access response.

[0145] After receiving the signal strength of the random access preamble sent by the second network device, the first network device can determine the path loss information of the second link based on the first transmit power of the random access preamble sent by the UE and the signal strength of the random access preamble received by the second network device. For example, the path loss information = α * (first transmit power - signal strength of the random access preamble) + β, where α and β can be constants. For example, α is 1 and β is 0.

[0146] Optionally, when the first network device receives the signal strength of random access preambles sent by multiple network devices, it can determine the link with the best signal strength and determine the path loss information of that link.

[0147] For example, if the random access preamble of the second network device has the best signal strength, i.e., A1 > A2 and A1 > A3, then the first network device determines the path loss information on the second link based on the first transmission power and A1.

[0148] Alternatively, the first network device can send path loss information to the terminal device using existing messages. For example, the path loss information can be carried in a random access response (RAR), i.e., message 2 (MSG 2).

[0149] For example, please refer to Table 1, which is a schematic table of road loss information carried in a RAR provided in an embodiment of this application:

[0150] Table 1

[0151] As shown in Table 1, the RAR grant field sent by the first network device includes: a frequency hopping flag (1 bit); a physical uplink shared channel (PUSCH) frequency domain resource allocation field (14 bits); a PUSCH time resource allocation field (4 bits); a modulation and coding scheme (MCS) field (4 bits); a PUSCH transmission power command (TPC) field (3 bits); and a channel state information (CSI) request field (1 bit). Optionally, this embodiment adds a path loss information (PL) field to the RAR grant field, which occupies X bits, where X is a positive integer.

[0152] Optionally, the first network device can send the path loss information to the terminal device via a separate, dedicated message. This dedicated message only carries the path loss information.

[0153] 305. The terminal device transmits uplink data information on the second link. The transmission power of the uplink data information is determined based on the target received power value and path loss information. The target received power value is the power value used by the second network device when receiving uplink data on the second link. Correspondingly, the second network device receives uplink data information on the second link.

[0154] After the UE obtains the path loss information on the second link sent by the first network device, it can determine the UE's transmission power on the second link based on the target received power value and the path loss information.

[0155] Optionally, the target received power value is defined as at least one of the following:

[0156] a. The power value used by the second network device when receiving uplink data information on the second link.

[0157] b. The target received power value is the target detection value or target threshold when the second network device receives uplink information on the second link.

[0158] For example, the second network device receives a target power value detection signal on the second link.

[0159] In other words, when the second network device performs uplink signal detection on the second link, the signal strength it can detect corresponds to the target detection value. The signal strength that the second network device can detect on the second link is greater than or equal to the target threshold.

[0160] Therefore, the target received power value and the target detection value can be range values, while the target threshold is a single value.

[0161] The UE determines the transmission power on the second link based on the target received power value and path loss information. Specifically, it can be: W = W1 + PL, where W represents the UE's transmission power on the second link, W1 represents the target received power value, and path loss information represents the path loss corresponding to the path loss information.

[0162] After determining the transmission power on the second link, the UE can send uplink data information to the second network device on the second link according to the transmission power. Optionally, the uplink data information can be message 3 (MSG 3). It can also be other uplink data information, which will not be described in detail here.

[0163] As can be seen, in this embodiment, after the first network device obtains the signal strength of the received random access preamble of the second network device on the second link, it calculates the path loss information of the second link based on the signal strength of the random access preamble and the first transmission power of the terminal device transmitting the random access preamble on the second link. The path loss information is then indicated to the terminal device, enabling the terminal device to determine its transmission power on the second link based on the path loss information and the target received power value of the second network device. This achieves uplink data transmission with the second network device. This method ensures that the UE can detect and access the second network device, achieving communication transmission, even when the UE cannot obtain the downlink reference signal sent by the second network device. It expands the communication scenarios of the terminal device and ensures the reliability of the terminal device obtaining network services.

[0164] Optionally, before the terminal device sends uplink data information on the second link, the method further includes: the first network device sending a target received power value to the terminal device.

[0165] Optionally, the first network device sends first information to the terminal device, the first information including a target received power value. The first network device also sends the target received power value to the second network device.

[0166] For example, the first information, as described in Embodiment 1 above, can be carried in DCI or RRC signaling. The target received power and the first transmitted power, first threshold value, and / or RACH resource set information in the aforementioned first information can be sent in the same message or in different messages.

[0167] Optionally, the target received power value is carried in the RAR message. That is, the target received power value is sent to the UE via RAR, just like the PL.

[0168] The first network device can send the target received power value after receiving the signal strength of the random access preamble from the second network device. Assuming the first network device receives multiple random access preamble signal strengths from TRPs (Telecommunications Protocols) that only receive uplink signals, it determines that the signal strength of the random access preamble sent by the second network device is the best. Therefore, it determines to establish communication between the second network device and the UE on the second link. At this time, the first network device sends the target received power value of the second network device to the UE.

[0169] Optionally, the first network device can send multiple received power values ​​and their indices to the UE via first information, whereby the multiple received power values ​​include the target received power value corresponding to the second network device. When the first network device determines that the signal strength of the random access preamble sent by the second network device is the best, it can indicate the index of the target received power value to the UE, thereby enabling the UE to determine the target received power value of the second network device.

[0170] As can be seen, this application embodiment provides a method for a first network device to send the target received power value of a second network device to a terminal device. Sending both path loss information and the target received power value simultaneously via a RAR message improves the ease with which the terminal device obtains this information. Sending the target received power value via a separate message reduces the complexity of the RAR message field design. By having the first network device send multiple received power values ​​first, and then indicating the index of the target received power value to the terminal device when establishing a communication connection between the second network device and the terminal device, mistransmission of the target received power during transmission can be avoided, ensuring the accuracy of the obtained target received power.

[0171] Example 3:

[0172] The above embodiments describe the process by which a terminal device discovers a second link, accesses a second network device on the second link, and establishes communication with the second network device. In some cases, the terminal device may not be able to access the second network device after sending a random access preamble only once.

[0173] Referring to Figure 4, which is a flowchart of another communication method of the system in this application embodiment, the method includes the following steps:

[0174] 401. The terminal device detects that the signal strength of the downlink reference signal is less than the first threshold value on the first link, and sets K=1. The first link corresponds to the first network device.

[0175] 402. The terminal device transmits the random access preamble for the Kth time on the first link at the first transmission power.

[0176] The second link is a link that only transmits uplink signals. The second link corresponds to the second network device.

[0177] When K=1, steps 401 to 402 can be referred to the descriptions of steps 201 and 202 above.

[0178] 403. The terminal device determines whether it receives a random access response from the first network device within a preset time.

[0179] The preset time is a time window.

[0180] 404. If no random access response is received from the first network device within the preset time, the terminal device determines whether K is equal to M.

[0181] In this embodiment, there is a situation where the UE transmits the random access preamble on the second link at the first transmit power, but does not receive the RAR from the first network device. Possible reasons include the following:

[0182] (1) The second network device did not receive the random access preamble.

[0183] (2) The second network device did not send the signal strength of the random access preamble to the first network device. Or the first network device did not receive the signal strength of the random access preamble sent by the second network device.

[0184] For example, the first network device sets a minimum received strength value and sends this minimum received strength value to the second network device. When the signal strength of the random access preamble sent by the second network device is less than the minimum received strength value, the second network device does not send the signal strength of the random access preamble.

[0185] Alternatively, the second network device may send the signal strength of the random access preamble, but due to a communication failure, the first network device may not receive the signal strength of the random access preamble.

[0186] (3) The first network device does not send a random access response.

[0187] For example, the first network device receives the signal strength of the random access preamble sent by the second network device, but the signal strength of the random access preamble does not meet the requirements, or the first network device does not have the remaining resources to process the service, etc., which causes the first network device not to send the RAR.

[0188] The preset time can be specified by the protocol, set by the UE itself, or configured by the first network device.

[0189] 405. If K < M, then promote K. Optionally, the terminal device sets K to K = K + 1 and repeats step 402.

[0190] 406. If K = M, then the terminal device transmits the signal on the first link according to the second transmission power.

[0191] As described in step 404, if the UE does not receive a RAR from the first network device, it prepares to perform the Kth cycle of transmitting the random access preamble. The preparation process includes:

[0192] 1) The value of K is incremented by 1. When the execution from step 402 to step 404 is executed for the first time, K = 1 for step 402, so K = K + 1 = 2 in step 405; when the execution from step 402 to step 404 is executed for the first time in a loop, K = 2 for step 402, so K = K + 1 = 3 in step 405; and so on.

[0193] 2) Determine if the value of K is equal to M. M is the maximum number of times a random access can be initiated. The initial value of K is 1, which is accumulated during the loop execution of step 405. If K < M, it means that the number of times the random access preamble has been sent in the loop has not yet reached the maximum number of times a random access can be initiated. In this case, the process can proceed from step 405 to step 402, and the random access preamble can be sent to the second network device again.

[0194] If K = M, it means that the number of times the random access preamble has been sent has reached the maximum number of times to initiate random access. The UE will no longer send the random access preamble, but will return to (or remain on) the first link and send signals according to the second transmission power to realize signal transmission with the first network device.

[0195] Where K and M are both positive integers. M can be configured by the first network device for the UE, or it can be specified by the protocol, or it can be set by the UE itself.

[0196] It should be noted that the UE transmits the random access preamble K times on the second link, and the transmission power of each random access preamble is the same as the first transmission power. That is, the UE transmits the random access preamble on the second link at a fixed first transmission power and will not actively change the transmission power due to changes in channel conditions (if, during the transmission of the K random access preambles, the first network device indicates an updated second transmission power to the UE, then the UE passively changes its transmission power). In other words, the UE transmits the random access preamble K times on the second link without power ramping.

[0197] 407. If the terminal device receives a random access response from the first network device within a preset time, the terminal device sends uplink data information on the second link.

[0198] The random access response includes path loss information, which is determined based on the signal strength of the random access preamble received by the second network device and the first transmit power. The transmission power of the uplink data information is determined based on the target receive power value and the path loss information. The target receive power value is the power value used by the second network device when receiving uplink data on the second link.

[0199] Assuming that the UE receives a RAR from the first network device within a preset time, and the RAR includes path loss information, the UE can send uplink data information on the second link to transmit uplink data information with the second network device. The specific process can be found in the descriptions of steps 304 and 305 in the aforementioned embodiments, and will not be repeated here.

[0200] As can be seen, in this embodiment, setting a maximum number of random access attempts initiated by the terminal device helps control its energy consumption and prevents it from consuming excessive resources to initiate random access on unreachable links. Furthermore, if the terminal device fails to initiate the maximum number of random access attempts on the second link, it can fall back to the first link for communication, ensuring that the terminal device can continuously obtain network services.

[0201] Example 4:

[0202] The method embodiments of this application can be combined with SUL technology scenarios.

[0203] Referring to Figure 5A, which is a flowchart of another communication method provided in an embodiment of this application, the method includes the following steps:

[0204] 501. The terminal device detects the downlink reference signal on the first link. The first link corresponds to the first network device.

[0205] 502. When the signal strength of the downlink reference signal is detected to be less than the first threshold, the terminal device transmits a random access preamble on the second link at the first transmit power. The second link is a link that only transmits uplink signals, and the second link corresponds to the second network device.

[0206] Referring to Figure 5B, which illustrates a multi-link communication system with a SUL carrier according to an embodiment of this application, the method of this embodiment is applied to this communication system. As shown in Figure 5B, the communication system includes a first link, a second link, a first network device, and a second network device. Their descriptions can be found in the relevant description in Figure 2B of the aforementioned embodiment. Furthermore, in this communication system, the second network device is a co-located network device, meaning that the second link can communicate with the second network device via both NUL and NDL, and also via SUL.

[0207] For a description of steps 501 and 502 of the method in this embodiment, please refer to the description of steps 201 and 202 in the aforementioned embodiment 1, which will not be repeated here.

[0208] 503. When the signal strength of the detected downlink reference signal is less than the second threshold and greater than or equal to the first threshold, the terminal device transmits the signal on the first uplink carrier of the first link. The first threshold is less than the second threshold.

[0209] The signal strength of the downlink reference signal detected by the UE on the first link is the current signal strength. When the first threshold value is ≤ (less than or equal to) the current signal strength < (less than) the second threshold value, the UE transmits the signal on the first uplink carrier of the first link. The first uplink carrier can be a SUL carrier. The first threshold value can be defined as the minimum value at which the UE directly transmits the signal on the first link (without probing the second link).

[0210] 504. When the signal strength of the downlink reference signal is detected to be greater than or equal to the second threshold value, the terminal device transmits the signal on the second uplink carrier of the first link.

[0211] Assuming the UE detects a current signal strength ≥ (greater than or equal to) a second threshold value on the first link, the UE transmits a signal on the second uplink carrier of the first link. The second uplink carrier can be an NUL carrier. The second threshold value can be defined as the threshold value that triggers the UE to select an uplink carrier on the first link.

[0212] Optionally, the second threshold value can be the value of the first threshold in the protocol.

[0213] Optionally, the second threshold value can be a value configured by the first network device for the terminal device.

[0214] Specifically, the second threshold value can be configured to the UE via messages such as DCI or RRC signaling. The second threshold value can be configured to the UE in the same message as the first threshold value, or it can be configured to the UE in different messages.

[0215] As can be seen, this embodiment provides a method for the terminal device to determine whether to initiate random access based on whether the detected downlink reference signal is less than a first threshold value. Furthermore, in the case of supplementary uplink carriers or co-location of conventional uplink carriers, the terminal device determines whether to communicate with the second network device on the first link via supplementary uplink carriers or conventional uplink carriers based on whether the detected downlink reference signal is less than a second threshold value. This ensures the richness of scenarios for the terminal device to access network devices and the reliability of the communication process.

[0216] Optionally, this embodiment can be combined with the foregoing embodiments. For example, when this embodiment is combined with Embodiment 2, after step 502, steps 303 to 305 from Embodiment 2 can also be included, which will not be repeated here.

[0217] Optionally, this embodiment can be combined with the aforementioned Embodiment 3. Similarly, when the signal strength of the downlink reference signal detected on the first link is less than a first threshold, the UE can initiate K random access attempts, where K ≤ M. If the UE does not receive a RAR from the first network device after initiating K random access attempts, the UE then communicates with the second network device on the first link. Optionally, the UE can specifically communicate with the second network device on the first link via a SUL carrier, because the SUL carrier has lower signal strength requirements.

[0218] Example 5:

[0219] The method embodiments of this application can be combined with multi-beam technology scenarios.

[0220] Referring to Figure 6A, which is a flowchart of another communication method provided in an embodiment of this application, the method includes the following steps:

[0221] 601. The terminal device detects the downlink reference signal on the first link. The first link corresponds to the first network device.

[0222] 602. When the signal strength of the downlink reference signal is detected to be less than a first threshold, the terminal device transmits a random access preamble on the second link at a first transmit power. The first threshold is associated with the first synchronization signal block (SSB) index, and the first SSB is the SSB detected at the current location of the terminal device. The second link is a link that only transmits uplink signals. The second link corresponds to the second network device.

[0223] Referring to Figure 6B, which illustrates a multi-beam multi-link communication system provided in this embodiment, the method of this embodiment is applied to this communication system. As shown in Figure 6B, the communication system includes a first network device (macro base station) and a second network device (any one of TRP1 to TRP3). The UE communicates with the first network device and the second network device on the first link and the second link, respectively. For a description of them, please refer to the relevant description in Figure 2B of the aforementioned embodiment. Furthermore, in this communication system, the first network device communicates in multiple beam coverage directions. As shown in Figure 6B, different beam coverage directions correspond to different synchronization signal block (SSB) indices. There are a total of 8 SSB indices, specifically SSB 0 to SSB 7. Because the communication capabilities of the first network device differ in different beam coverage directions, the signal strength requirements for the UE to communicate with the first network device in that beam coverage direction may also differ. In this embodiment, different SSB indices correspond to different threshold values.

[0224] Specific examples are as follows:

[0225] SSB 0~SSB 2: Corresponds to the first threshold value of 0;

[0226] SSB 2~SSB 4: Corresponding to the first threshold value of 1;

[0227] SSB 5~SSB 7: Corresponding to the first threshold value of 2.

[0228] When a UE accesses the first network device, it needs to detect the SSB from the first network device to determine the SSB index. If the UE and the first network device have not established a connection, it can be said that the downlink reference signal detected on the first link includes the SSB. If the UE and the first network device have established a connection, the method of this embodiment, before step 601, further includes (not shown in the figure) the terminal device detecting the SSB on the first link and obtaining the SSB index.

[0229] The SSB index obtained by UE1 is SSB 1, and its corresponding configured threshold value is the first threshold value of 0. Then, UE1 determines whether to initiate random access on the second link according to the first threshold value.

[0230] Assuming UE3 obtains SSB index 4, and the corresponding configured threshold value is the first threshold value 1, then the UE determines whether to initiate random access on the second link according to the first threshold value 1. That is, when UE3 detects that the signal strength of the downlink reference signal on the first link is less than the first threshold value 1, it initiates random access on the second link.

[0231] Optionally, each SSB index can have its own threshold value. For example:

[0232] SSB 0: Corresponds to the first threshold value of 0;

[0233] SSB 1: Corresponds to the first threshold value of 1;

[0234] SSB 2: Corresponds to the first threshold value of 2;

[0235] ...

[0236] SSB 7: Corresponds to the first threshold value of 7.

[0237] That is, there is a corresponding threshold value for each SSB index. Similarly, the UE obtains the corresponding first threshold value based on the SSB index obtained from the current location detection, and determines whether to initiate random access on the second link based on the first threshold value.

[0238] As can be seen, in this embodiment, establishing the association between a threshold value and an SSB index enables the terminal device to determine whether to initiate random access based on a first threshold value associated with the SSB index of the beam when it is covered by different beams at different locations. This ensures that the terminal device can make a more accurate judgment on the access method based on its current location, thereby ensuring the reliability of network communication for the terminal device.

[0239] Optionally, this embodiment can be combined with the foregoing embodiments. For example, when this embodiment is combined with Embodiment 2, after step 602, steps 303 to 305 from Embodiment 2 can also be included, which will not be repeated here.

[0240] Optionally, this embodiment can be combined with the aforementioned Embodiment 3, that is, when the signal strength of the downlink reference signal detected on the first link is less than a first threshold value, the UE can initiate K random access attempts, where K≤M. If the UE does not receive a RAR from the first network device after initiating K random access attempts, the UE then communicates with the second network device on the first link.

[0241] Optionally, this embodiment can be combined with the aforementioned embodiment four. That is, the UE can also determine the second threshold value based on the SSB index detected at the current location, and when the signal strength of the downlink reference signal on the first link is greater than or equal to the first threshold value, determine whether to communicate with the second network device on the SUL carrier or NUL carrier based on the relationship between the signal strength of the downlink reference signal and the second threshold value.

[0242] Please refer to Figure 7, which is a schematic diagram of a communication device provided in an embodiment of this application. This communication device can be used to execute any of the methods in the foregoing embodiments.

[0243] As shown in Figure 7, the communication device includes a processing module 1501 and a transceiver module 1502. The processing module 1501 may be one or more processors, and the transceiver module 1502 may be a transceiver or a communication interface. This communication device can be used to implement the functions of the first and second devices involved in any of the above method embodiments. These devices may be hardware devices, software functions running on dedicated hardware, or virtualization functions instantiated on a platform (e.g., a cloud platform). Optionally, the communication device may also include a storage module 1503 for storing the program code and data of the communication device.

[0244] In the first example, the communication device can be used as a terminal device or a chip in a terminal device as described in Embodiments 1 to 5, and execute the steps performed by the terminal device in the above method embodiments. The transceiver module 1502 is used to support communication with a first network device or a second network device, etc. The processing module 1501 can be used to support the execution of actions performed by the terminal device in the above method embodiments, other than sending and receiving.

[0245] Specifically, the transceiver module 1502 is used to detect downlink reference signals on the first link;

[0246] The processing module 1501 is used to send a random access preamble on the second link at a first transmission power when the signal strength of the downlink reference signal is detected to be less than a first threshold value; the second link is a link that only transmits uplink signals, the first link corresponds to the first network device, and the second link corresponds to the second network device.

[0247] In one feasible implementation, the transceiver module 1502 is further configured to receive a random access response from the first network device, the random access response including path loss information of the second link; and to send uplink data information on the second link, wherein the transmission power of the uplink data information is determined based on the target received power value and the path loss information, the target received power value being the power value used by the second network device when receiving uplink data information on the second link.

[0248] In one feasible implementation, the transceiver module 1502 is further configured to receive first information from the first network device, the first information including a target received power value.

[0249] In one feasible implementation, the first information further includes at least one of the following: a first threshold value, a first transmission power, and a RACH resource set, wherein the RACH resource set includes RACH resources for the terminal device to transmit a random access preamble on the second link.

[0250] In one feasible implementation, the second link is different from the first link, which is a link with downlink reference signal transmission.

[0251] In one feasible implementation, the uplink data information is message 3.

[0252] In one feasible implementation, a random access preamble is transmitted on the second link at a first transmit power, including:

[0253] Send K random access preambles. The transmission power of the K random access preambles is the first transmission power. K is less than or equal to M, where M is the maximum number of random access attempts. K and M are positive integers.

[0254] In one feasible implementation, the processing module 1501 is further configured to: if K equals M and no random access response is received, then the receiving transceiver module 1502 transmits a signal on the first link according to a second transmission power, the second transmission power being used by the terminal device for communication transmission on the first link.

[0255] In one feasible implementation, the first link includes a first uplink carrier and a second uplink carrier. The processing module 1501 is further configured to: when the signal strength of the downlink reference signal is detected to be less than a second threshold value and greater than or equal to a first threshold value, transmit the signal on the first uplink carrier of the first link in conjunction with the transceiver module 1502, wherein the first threshold value is less than the second threshold value.

[0256] When the signal strength of the downlink reference signal is detected to be greater than or equal to the second threshold value, the transceiver module 1502 transmits the signal on the second uplink carrier of the first link.

[0257] In one feasible implementation, the first threshold value is associated with the first synchronization signal block SSB index, where the first SSB is the SSB detected at the current location of the terminal device.

[0258] In a second example, the communication device can function as the first network device or a chip within the first network device in Embodiments 1 to 5, and execute the steps performed by the first network device in the above method embodiments. The transceiver module 1502 supports communication with the terminal device and the second network device. The processing module 1501 can be used to support the execution of actions performed by the first network device in the above method embodiments, excluding sending and receiving.

[0259] Specifically, the transceiver module 1502 is used to receive second information from the second network device. The second information includes the signal strength of the random access preamble received by the second network device. The random access preamble is transmitted by the terminal device on the second link at the first transmission power. The second link is a link that only transmits uplink signals.

[0260] The transceiver module 1502 is also used to send a random access response to the terminal device. The random access response includes path loss information, which is determined based on the signal strength of the random access preamble received by the second network device and the first transmission power.

[0261] In one feasible implementation, the transceiver module 1502 is further configured to: send first information to the terminal device, the first information including a target received power value, the target received power value being the power value used by the second network device when receiving uplink data on the second link.

[0262] In one feasible implementation, the first information further includes at least one of the following: a first threshold value, a first transmit power value, and a RACH resource set, wherein the first threshold value is the maximum signal strength that triggers the terminal device to transmit a random access preamble on the second link, and the RACH resource set includes RACH resources for the terminal device to transmit a random access preamble on the second link.

[0263] In one feasible implementation, the second information also includes the RACH resource identifier of the second link.

[0264] In one feasible implementation, the first transmission power is a preset value.

[0265] In one feasible implementation, the second link is different from the first link, which is a link with downlink reference signal transmission.

[0266] In one feasible implementation, when the first information includes a first threshold value, the first information includes the association between multiple threshold values ​​and multiple synchronization signal block (SSB) indices, including the association between the first threshold value and the first SSB index.

[0267] In a third example, the communication device can function as the second network device or a chip within the second network device in Embodiments 1 to 5, and execute the steps performed by the second network device in the above method embodiments. The transceiver module 1502 supports communication between the terminal device and the first network device. The processing module 1501 can be used to support the execution of actions performed by the second network device in the above method embodiments, excluding sending and receiving.

[0268] Specifically, the transceiver module 1502 is used to receive a random access preamble from the terminal device on the second link, wherein the random access preamble is sent by the terminal device according to the first transmission power, and the second link is a link that only transmits uplink signals.

[0269] The transceiver module 1502 is also used to send second information to the first network device, the second information including the signal strength of the received random access preamble;

[0270] The transceiver module 1502 is also used to receive uplink data information from the terminal device on the second link. The transmission power of the uplink data information is determined based on the target received power value and path loss information. The target received power value is the power value used by the second network device when receiving uplink data on the second link. The path loss information is determined based on the signal strength of the random access preamble received by the second network device and the first transmission power.

[0271] In one feasible implementation, the second information also includes the RACH resource identifier corresponding to the second link.

[0272] The processing module 1501 may be a processor that can execute computer execution instructions stored in the storage module to cause the chip to perform the methods involved in any of the above embodiments.

[0273] Please refer to Figure 8, which is a simplified structural diagram of a network device provided in an embodiment of this application, and can be used as an implementation of the first device of this application.

[0274] The network device includes a radio frequency (RF) signal transceiver and conversion section and a baseband section 42. The RF signal transceiver and conversion section further includes a receiving module 41 and a transmitting module 43 (which can also be collectively referred to as transceiver modules). The RF signal transceiver and conversion section is mainly used for transmitting and receiving RF signals and converting RF signals to baseband signals. The baseband section 42 is mainly used for baseband processing and controlling the network device. The receiving module 41 can also be called a receiver, receiver circuit, etc., and the transmitting module 43 can also be called a transmitter, transmitter, transmitter circuit, etc. The baseband section 42 is usually the control center of the network device, and can also be called a processing module, used to execute the steps performed by the network device in any of the above methods. See the description of the relevant sections above for details. The transmitting module 43 may include an antenna and RF circuitry. The RF circuitry is mainly used for converting baseband signals to RF signals and processing RF signals. The antenna is mainly used for transmitting and receiving RF signals in the form of electromagnetic waves.

[0275] The baseband section 42 may include one or more boards, each board may include one or more processors and one or more memories. The processors are used to read and execute programs in the memories to implement baseband processing functions and control network devices. If multiple boards exist, they can be interconnected to increase processing power. As an optional implementation, multiple boards may share one or more processors, multiple boards may share one or more memories, or multiple boards may simultaneously share one or more processors.

[0276] Please refer to Figure 9, which is a simplified structural diagram of a UE provided in an embodiment of this application, as an implementation of the second device in this application.

[0277] For ease of understanding and illustration, Figure 9 uses a mobile phone as an example of the UE. As shown in Figure 9, the UE includes at least one processor, and may also include radio frequency (RF) circuitry, an antenna, and input / output devices. The processor can be used to process communication protocols and communication data, as well as to control the UE, execute software programs, and process data from those programs. The UE may also include a memory, primarily used to store software programs and data. These programs can be loaded into the memory at the time of manufacture or added later when needed. The RF circuitry is mainly used for converting baseband signals to RF signals and processing RF signals. The antenna is mainly used for transmitting and receiving RF signals in the form of electromagnetic waves. Input / output devices, such as touchscreens, displays, and keyboards, are mainly used to receive user input data and output data to the user. It should be noted that some types of UEs may not have input / output devices.

[0278] When a signal needs to be transmitted, the processor performs baseband processing on the data to be transmitted and outputs the baseband signal to the radio frequency (RF) circuit. The RF circuit then processes the baseband signal and transmits it outward as an electromagnetic wave through the antenna. When data is sent to the UE, the RF circuit receives the RF signal through the antenna, converts it into a baseband signal, and outputs it to the processor. The processor converts the baseband signal back into data and processes it. For ease of explanation, Figure 9 only shows one memory and one processor. In actual UE products, there may be one or more processors and one or more memories. Memory can also be called storage medium or storage device, etc. Memory can be set up independently of the processor or integrated with the processor; this embodiment does not limit this.

[0279] In this embodiment, the antenna and radio frequency circuit with transceiver functions can be regarded as the receiving unit and transmitting unit of the UE (or collectively referred to as the transceiver unit), and the processor with processing functions can be regarded as the processing unit of the UE. As shown in Figure 9, the UE includes a receiving module 31, a processing module 32, and a transmitting module 33. The receiving module 31 can also be referred to as a receiver, receiver circuit, etc., and the transmitting module 33 can also be referred to as a transmitter, transmitter, transmitter circuit, etc. The processing module 32 can also be referred to as a processor, processing board, processing device, etc.

[0280] It is understood that the processor in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

[0281] Optionally, the memory may also store data. The processor and memory may be configured separately or integrated together. The memory may be non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), or it may be volatile memory, such as random-access memory (RAM). In the embodiments of this application, the processor may also be flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art.

[0282] Optionally, the UE may include instructions (sometimes referred to as code or program) that can be executed on the processor.

[0283] Optionally, the UE may also include a transceiver and an antenna. The transceiver may be referred to as a transceiver unit, transceiver module, transceiver, transceiver circuit, transceiver, input / output interface, etc., and is used to realize the UE's transmission and reception functions through the antenna.

[0284] This application provides a communication system, which includes the aforementioned terminal device, first network device, and second network device.

[0285] This application provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores computer instructions, which, when executed, cause the computer to perform the method described in any of the above methods.

[0286] This application provides a computer program product, which includes computer program code. When the computer program code is run, it causes the computer to perform the method described in any of the above methods.

[0287] This application provides a chip coupled to a memory for reading and executing program instructions in the memory, so that the device containing the chip implements the method described in any of the above methods.

[0288] In the above embodiments, the descriptions of each embodiment have their own emphasis. Parts not described in detail in a particular embodiment can be found in the relevant descriptions of other embodiments. It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0289] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical or other forms.

[0290] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0291] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A communication method, characterized in that, The method includes: Detect downlink reference signals on the first link; When the signal strength of the downlink reference signal is detected to be less than the first threshold, a random access preamble is transmitted on the second link at the first transmission power; the second link is a link that only transmits uplink signals, the first link corresponds to the first network device, and the second link corresponds to the second network device.

2. The method according to claim 1, characterized in that, The method further includes: Receive a random access response from the first network device, wherein the random access response includes path loss information of the second link; Uplink data information is transmitted on the second link. The transmission power of the uplink data information is determined based on the target received power value and the path loss information. The target received power value is the power value used by the second network device when receiving uplink data information on the second link.

3. The method according to claim 2, characterized in that, The method further includes: Receive first information from the first network device, the first information including the target received power value.

4. The method according to claim 3, characterized in that, The first information also includes at least one of the following: the first threshold value, the first transmission power, and the RACH resource set, wherein the RACH resource set includes RACH resources for the terminal device to transmit random access preambles on the second link.

5. The method according to any one of claims 2-4, characterized in that, The path loss information is determined based on the signal strength of the random access preamble received by the second network device and the first transmission power.

6. The method according to any one of claims 1-5, characterized in that, The first transmission power is a preset value.

7. The method according to claim 2, characterized in that, The uplink data information is message 3.

8. The method according to any one of claims 1-7, characterized in that, The transmission of the random access preamble on the second link at the first transmission power includes: Send K random access preambles, where the transmission power of the K random access preambles is the first transmission power, K is less than or equal to M, M is the maximum number of times random access can be initiated, and K and M are positive integers.

9. The method according to claim 8, characterized in that, The method further includes: If K equals M and no random access response is received, then a signal is transmitted on the first link at a second transmission power, which is used by the terminal device when it performs communication transmission on the first link.

10. The method according to any one of claims 1-9, characterized in that, The first link includes a first uplink carrier and a second uplink carrier, and the method further includes: When the signal strength of the downlink reference signal is detected to be less than the second threshold and greater than or equal to the first threshold, the terminal device transmits a signal on the first uplink carrier of the first link, wherein the first threshold is less than the second threshold. When the signal strength of the downlink reference signal is detected to be greater than or equal to the second threshold value, the terminal device transmits a signal on the second uplink carrier of the first link.

11. The method according to any one of claims 1-10, characterized in that, The first threshold value is associated with the first synchronization signal block SSB index, where the first SSB is the SSB detected at the current location of the terminal device.

12. A communication method, characterized in that, The method includes: Receive second information from a second network device, the second information including the signal strength of the random access preamble received by the second network device, wherein the random access preamble is transmitted by the terminal device on the second link at a first transmission power, and the second link is a link that only transmits uplink signals; A random access response is sent to the terminal device, the random access response including path loss information, the path loss information being determined based on the signal strength of the random access preamble received by the second network device and the first transmission power.

13. The method according to claim 12, characterized in that, The method further includes: Send first information to the terminal device, the first information including a target received power value, the target received power value being the power value used by the second network device when receiving uplink data on the second link.

14. The method according to claim 13, characterized in that, The first information also includes at least one of the following: a first threshold value, a first transmit power value, and a RACH resource set, wherein the first threshold value is the maximum signal strength that triggers the terminal device to transmit a random access preamble on the second link, and the RACH resource set includes RACH resources for the terminal device to transmit a random access preamble on the second link.

15. The method according to claim 14, characterized in that, The second information also includes the RACH resource identifier of the second link.

16. The method according to any one of claims 13-15, characterized in that, The first transmission power is a preset value.

17. The method according to any one of claims 14-16, characterized in that, When the first information includes the first threshold value, the first information includes the association between multiple threshold values ​​and multiple synchronization signal block (SSB) indices, including the association between the first threshold value and the first SSB index.

18. A communication method, characterized in that, The method includes: On the second link, a random access preamble is received from the terminal device, wherein the random access preamble is transmitted by the terminal device at a first transmission power, and the second link is a link that only transmits uplink signals; Send a second message to the first network device, the second message including the signal strength of the received random access preamble; Uplink data information from the terminal device is received on the second link. The transmission power of the uplink data information is determined based on the target received power value and path loss information. The target received power value is the power value used by the second network device when receiving uplink data on the second link. The path loss information is determined based on the signal strength of the random access preamble received by the second network device and the first transmission power.

19. The method according to claim 18, characterized in that, The second information also includes the RACH resource identifier corresponding to the second link.

20. A communication device, characterized in that, Used to implement the method as described in any one of claims 1 to 11.

21. The apparatus according to claim 20, characterized in that, The device includes a terminal device or a chip.

22. A communication device, characterized in that, Used to implement the method as described in any one of claims 12 to 19.

23. The apparatus according to claim 22, characterized in that, The device includes network equipment or a chip.

24. A communication device, characterized in that, The communication device includes at least one processor coupled to a memory; The at least one processor is configured to execute a computer program or instructions stored in the memory, such that the method as described in any one of claims 1 to 11 is implemented, or the method as described in any one of claims 12 to 19 is implemented.

25. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed, causes the method as described in any one of claims 1 to 11 to be implemented, or causes the method as described in any one of claims 12 to 19 to be implemented.

26. A computer program, characterized in that, When the computer program is run, it causes the method as described in any one of claims 1 to 11 to be implemented, or causes the method as described in any one of claims 12 to 19 to be implemented.

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