Communication method and device

Abstract

The invention discloses a communication method and device. The terminal device transmits a first message. And the terminal device detects the PDCCH when or after a first time length in which the first message is sent is reached, and the terminal device does not detect the PDCCH within the first time length. The first duration is determined according to a round-trip delay between an access network element of the service terminal device and a core network element of the service terminal device, and a communication link between the access network element and the core network element comprises a link between a satellite and the ground. According to the embodiment of the invention, the receiving of information from a network by the terminal device is not influenced, and the time for detecting the PDCCH by the terminal device can be reduced, so that the power consumption of the terminal device is saved.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication method and apparatus. Background Technology

[0002] Non-terrestrial networks (NTNs) are networks or network segments that use airborne or space-based vehicles to carry relay nodes or base stations. A typical NTN provides communication services via satellite. NTNs have various architectures, one of which is the regenerative satellite architecture, also known as regenerative architecture, regenerative mode, or regenerative scenario. In the regenerative scenario, the satellite has the processing capabilities of a base station, essentially deploying the functions of a base station on the satellite.

[0003] In NTN, after a user equipment (UE) sends information to the network, it can wait for a response. Some responses are sent by the base station, while others are sent by core network elements. In regeneration scenarios, the base station's functionality is deployed on satellites, while the core network elements are located on the ground. For responses from core network elements, the transmission delay can be relatively long. Furthermore, after sending a signal, the UE checks the physical downlink control channel (PDCCH) to await a network response, which can lead to significant power consumption. Summary of the Invention

[0004] This application provides a communication method and apparatus for reducing the power consumption of a UE.

[0005] Firstly, a first communication method is provided, which can be applied to the terminal side, for example, and can be executed by a terminal device. The terminal device is, for example, a terminal equipment, or other equipment including terminal equipment functions, or a circuit, or a system-on-a-chip (or, a chip, such as a modem chip, also known as a baseband chip, or a system-on-a-chip (SoC) chip containing a modem core, or a system-in-package (SIP) chip) or other functional module, which is capable of implementing the functions of the terminal equipment, and which is, for example, disposed in the terminal equipment. The method includes: sending a first message; detecting a PDCCH when or after a first duration has elapsed since the first message was sent, wherein the PDCCH is not detected during the first duration.

[0006] In one optional implementation, the first duration is determined based on the round-trip time between the access network element of the serving terminal device and the core network element serving the terminal device, wherein the communication link between the access network element and the core network element includes a satellite-to-ground link.

[0007] In this embodiment, after the terminal device sends the first message, it can start detecting the PDCCH when or after the first duration has elapsed, but not during the first duration. This reduces the time the terminal device spends detecting the PDCCH and saves power. Optionally, the first duration is determined based on the round-trip time between the access network element and the core network element. For example, in a regeneration scenario, the first duration takes into account the round-trip time between the satellite and the ground. This means that the terminal device can skip detecting the PDCCH during the transmission of the network reply information, and only detect the PDCCH when the information is about to arrive at the terminal device to receive it. Therefore, this embodiment does not affect the terminal device's reception of information from the network and reduces the time the terminal device spends detecting the PDCCH, thereby saving power.

[0008] In one optional implementation, the access network element is located on the satellite, or the access network element is the satellite. The first duration includes a second duration and a third duration. The second duration is determined based on the round-trip time between the access network element and the core network element, and the third duration is determined based on the round-trip time between the terminal device and the access network element. The terminal device's waiting time (e.g., the time during which it does not detect the PDCCH) may include the round-trip time between the terminal device and the access network element, and the round-trip time between the access network element and the core network element. Since the access network element is located on the satellite, the core network element is located on the ground (e.g., on the ground), and the terminal device is also located on the ground, the terminal device can determine the third duration itself, for example, based on ephemeris time. It can also determine the second duration, thereby allowing the terminal device to not detect the PDCCH during the first duration, thus saving power.

[0009] In an optional implementation, the method further includes: receiving a first parameter, the first parameter being used to determine the first duration or the second duration; or, receiving information about the second duration. The terminal device can directly receive the information about the second duration, thus determining the second duration without calculation, simplifying the implementation of the terminal device; alternatively, the terminal device can also determine the first duration or the second duration based on the first parameter, in which case the first duration or the second duration does not need to be calculated by the access network element or other network elements, reducing the burden on the access network element or other network elements.

[0010] In one optional implementation, the access network element and the core network element are located on the ground, and the access network element and the core network element communicate via the satellite. The first duration is determined based on the round-trip time between the access network element serving the terminal device and the core network element serving the terminal device, including: the first duration is determined based on the round-trip time between the access network element and the satellite, and the round-trip time between the satellite and the core network element. If both the access network element and the core network element are located on the ground, and the access network element and the core network element communicate via satellite, then the waiting time of the terminal device (e.g., the time during which the PDCCH is not detected) mainly includes the round-trip time between the access network element and the core network element. The round-trip time between the terminal device and the access network element is small and negligible since both the terminal device and the access network element are located on the ground. Therefore, the terminal device can determine the first duration overall, thereby allowing the terminal device to not detect the PDCCH during the first duration to save power.

[0011] In an optional implementation, the method further includes: receiving a first parameter, the first parameter being used to determine the first duration; or, receiving information about the first duration. The terminal device can directly receive the information about the first duration, thus determining the first duration without calculation, simplifying the implementation of the terminal device; alternatively, the terminal device can also determine the first duration based on the first parameter, in which case the first duration does not need to be calculated by the access network element or other network elements, reducing the burden on the access network element or other network elements.

[0012] In one alternative implementation, the first parameter is included in system information. The first parameter may be included in a broadcast message, such as a system message, or other broadcast message. Alternatively, the first parameter may also be included in a unicast message; there is no limitation on this.

[0013] In one optional implementation, the first message is used to request registration with the first core network element, for example, the first message is a registration request; or, the first message is used to request services from the first core network element, for example, the first message is a service request; or, the first message is used to respond to the authentication result of the terminal device to the first core network element, or to send the authentication response of the terminal device to the first core network element, for example, the first message is an authentication response; or, the first message is used to respond to NAS security configuration to the first core network element, or to send a NAS security command response to the first core network element, for example, the first message is a NAS security command response; or, the first message is used to request the establishment of an RRC connection with the access network element during small packet transmission, for example, the first message is an RRC connection establishment request message.

[0014] In one optional implementation, the first message is the RRC connection establishment request message. Detecting the PDCCH includes: starting a first timer and detecting the PDCCH during the operation of the first timer. Optionally, the first timer may be, for example, a contention resolution timer, or other timers. When or after the first timer times out, the terminal device can stop detecting the PDCCH, thereby reasonably stopping the detection process and saving power.

[0015] In an optional implementation, the method further includes: receiving a contention resolution message in response to the PDCCH. For example, if the first message is an RRC connection establishment request message, then after the terminal device sends the RRC connection establishment request message, the access network element can reply with a contention resolution message, which can be scheduled via the PDCCH. The terminal device can receive the contention resolution message according to the PDCCH scheduling by detecting the PDCCH.

[0016] In one optional implementation, the first message is the RRC connection establishment request message, which further includes uplink small packet data. If the terminal device has uplink data, it can send it to the access network element in the form of uplink small packet data through the RRC connection establishment request message. Thus, the terminal device can achieve data transmission without entering the RRC connection state, saving the resource consumption and power consumption caused by entering the RRC connection state.

[0017] Secondly, a second communication method is provided, which can be applied to the terminal side, for example, and can be executed by a terminal device. This terminal device is, for example, a terminal equipment, or other equipment including terminal equipment functions, or a circuit, or a system-on-a-chip (or chip, such as a modem chip, also known as a baseband chip, or a SoC chip or SIP chip containing a modem core) or other functional module, which can implement the functions of the terminal equipment, and is, for example, disposed within the terminal equipment. The method includes: receiving a contention resolution message during small packet transmission; detecting a PDCCH when or after a first duration following the completion of receiving the contention resolution message, wherein the PDCCH is not detected during the first duration.

[0018] In one optional implementation, the first duration is determined based on the round-trip time between the access network element of the serving terminal device and the core network element serving the terminal device, wherein the communication link between the access network element and the core network element includes a satellite-to-ground link.

[0019] In this embodiment, after receiving the contention resolution message, the terminal device can begin detecting the PDCCH either when or after the first duration has elapsed, but not during the first duration. This reduces the time the terminal device spends detecting the PDCCH and saves power. Optionally, the first duration is determined based on the round-trip time between the access network element and the core network element. For example, regardless of whether it's a regenerator satellite architecture or a radio backhaul architecture, the first duration takes into account the round-trip time between the satellite and the ground. This means that the UE can choose not to detect the PDCCH during the transmission of information replied from the network, but can detect the PDCCH when the information is about to arrive at the terminal device to receive it. Therefore, this embodiment does not affect the terminal device's reception of information from the network and reduces the time the terminal device spends ineffectively detecting the PDCCH, thereby saving power.

[0020] In one optional implementation, the access network element is located on the satellite, or the access network element is the satellite, wherein the first duration includes a second duration and a third duration, the second duration is determined based on the round-trip time delay between the access network element and the core network element, and the third duration is determined based on the round-trip time delay between the terminal device and the access network element.

[0021] In an optional implementation, the method further includes: receiving a first parameter, the first parameter being used to determine the first duration or the second duration; or, receiving information about the second duration.

[0022] In one optional implementation, the access network element and the core network element are located on the ground, and the access network element and the core network element communicate via the satellite. The first duration is determined based on the round-trip time between the access network element serving the terminal device and the core network element serving the terminal device, including: the first duration is determined based on the round-trip time between the access network element and the satellite, and the round-trip time between the satellite and the core network element.

[0023] In an optional implementation, the method further includes: receiving a first parameter, the first parameter being used to determine the first duration; or, receiving information about the first duration.

[0024] In one alternative implementation, the first parameter is included in the system information.

[0025] For the technical effects of the second aspect or various alternative implementation methods, please refer to the introduction of the technical effects of the first aspect or corresponding implementation methods.

[0026] Thirdly, a third communication method is provided, which can be applied to the network side, for example, and can be executed by a network device. This network device is, for example, a network equipment, or other equipment including network equipment functions, or a circuit, or a chip system (or chip) or other functional module capable of implementing the functions of the network equipment, and is, for example, disposed within the network equipment. The network equipment includes, for example, core network equipment and / or access network equipment. The method includes: sending first information, the first information including a first parameter, information of a first duration, or information of a second duration, wherein the first parameter is used to determine the first duration or the second duration, wherein the first duration includes the second duration, the second duration is determined based on the round-trip time delay between the access network element and the core network element, or the first duration is determined based on the round-trip time delay between the access network element and the satellite, and the round-trip time delay between the satellite and the core network element.

[0027] In one alternative implementation, the first information is included in the system information.

[0028] Regarding the technical effects of the third aspect or various alternative implementations, refer to the description of the technical effects of the first aspect or corresponding implementations, and / or refer to the description of the technical effects of the second aspect or corresponding implementations.

[0029] Fourthly, a communication device is provided. The communication device can be a terminal device as described in any of the first to third aspects above. The communication device possesses the functions of the aforementioned terminal device. For example, the communication device is capable of implementing the functions described in any of the first to third aspects above. For instance, the communication device includes modules, units, or means corresponding to the operations described in any of the first to third aspects above. These modules, units, or means can be implemented in software, hardware, or a combination of software and hardware. The communication device is, for example, a terminal device, or other device including the functions of a terminal device, or a chip system (or chip or circuit) or other functional module capable of implementing the functions of a terminal device. This chip system or functional module is, for example, disposed within a terminal device. In one optional implementation, the communication device includes a baseband device and a radio frequency device. In another optional implementation, the communication device includes a processing unit (sometimes also called a processing module) and a transceiver unit (sometimes also called a transceiver module). A transceiver unit can perform both sending and receiving functions. When the transceiver unit performs the sending function, it can be called a sending unit (sometimes also called a sending module), and when it performs the receiving function, it can be called a receiving unit (sometimes also called a receiving module). The sending unit and the receiving unit can be the same functional module, which is called the transceiver unit and can perform both sending and receiving functions; or, the sending unit and the receiving unit can be different functional modules, and the transceiver unit is a collective term for these functional modules.

[0030] In one optional implementation, the transceiver unit (or the sending unit) is configured to send a first message; the processing unit is configured to detect the PDCCH when or after a first duration following the completion of the first message transmission, wherein the PDCCH is not detected during the first duration. Optionally, the first duration is determined based on the round-trip time between the access network element of the serving terminal device and the core network element serving the terminal device, wherein the communication link between the access network element and the core network element includes a satellite-to-ground link.

[0031] In one optional implementation, the transceiver unit (or the receiving unit) is configured to receive a contention resolution message during small packet transmission; the processing unit is configured to detect the PDCCH when or after a first duration has elapsed since the completion of receiving the contention resolution message, wherein the PDCCH is not detected within the first duration. Optionally, the first duration is determined based on the round-trip time between the access network element of the serving terminal device and the core network element serving the terminal device, wherein the communication link between the access network element and the core network element includes a satellite-to-ground link.

[0032] In an alternative embodiment, the communication device further includes a storage unit (sometimes also called a storage module), and the processing unit is configured to couple with the storage unit and execute programs or instructions in the storage unit to enable the communication device to perform the functions of the terminal device described in any one of the first to third aspects above.

[0033] Fifthly, a communication device is provided. The communication device can be a network device as described in any of the first to third aspects above. The communication device possesses the functions of the aforementioned network device. For example, the communication device is capable of implementing the functions described in any of the first to third aspects above. For instance, the communication device includes modules, units, or means corresponding to the operations described in any of the first to third aspects above. These modules, units, or means can be implemented in software, hardware, or a combination of software and hardware. The communication device is, for example, a network device, or other device including network device functions, or a chip system (or chip or circuit) or other functional module capable of implementing the functions of a network device. This chip system or functional module is, for example, disposed within a network device. The network device includes, for example, core network equipment and / or access network equipment. In one optional implementation, the communication device includes a baseband device and a radio frequency device. In another optional implementation, the communication device includes a processing unit (sometimes also called a processing module) and a transceiver unit (sometimes also called a transceiver module). For details on the implementation of the transceiver unit, please refer to the relevant description in the fourth aspect.

[0034] In one optional implementation, the transceiver unit (or the sending unit) is configured to send first information, the first information including a first parameter, information of a first duration, or information of a second duration, wherein the first parameter is used to determine the first duration or the second duration, and the first duration includes the second duration. Optionally, the second duration is determined based on the round-trip time between the access network element and the core network element, or the first duration is determined based on the round-trip time between the access network element and the satellite, and the round-trip time between the satellite and the core network element.

[0035] In an alternative embodiment, the communication device further includes a storage unit (sometimes also called a storage module), and the processing unit is configured to couple with the storage unit and execute programs or instructions in the storage unit to enable the communication device to perform the functions of the network device described in any one of the first to third aspects above.

[0036] A sixth aspect provides a communication device comprising a memory and one or more processors. The memory stores part or all of a computer program or instructions necessary for implementing the functions described in the first or second aspect. The one or more processors are executable to carry out the computer program or instructions, which, when executed, cause the communication device to implement the methods in any possible design or implementation of the first or second aspect.

[0037] In one possible design, the communication device may further include an interface circuit, wherein the processor is used to communicate with other devices or components through the interface circuit.

[0038] In one possible design, the communication device may also include the memory.

[0039] The aforementioned communication device may be a terminal, a communication module in a terminal, or a chip in a terminal that is responsible for communication functions, such as a modem chip (also known as a baseband chip) or a SoC or SIP chip containing a modem module.

[0040] A seventh aspect provides a communication device comprising a memory and one or more processors. The memory stores part or all of a computer program or instructions necessary for implementing the functions described in the third aspect above. The one or more processors are executable to carry out the computer program or instructions, such that, when executed, the communication device implements the methods in any possible design or implementation of the third aspect above.

[0041] In one possible design, the communication device may further include an interface circuit, wherein the processor is used to communicate with other devices or components through the interface circuit.

[0042] In one possible design, the communication device may also include the memory.

[0043] The aforementioned communication device may be a network device, a communication module in a network device, or a chip in a network device that is responsible for communication functions, such as a modem chip (also known as a baseband chip) or a SoC or SIP chip that contains a modem module.

[0044] Eighthly, a communication system is provided, comprising a terminal device and a network device, wherein the network device is configured to perform the method described in any one of the first to third aspects, and the terminal device is configured to perform the method described in any one of the first to third aspects. For example, the network device may be implemented using the communication device described in the fifth or seventh aspect, and the terminal device may be implemented using the communication device described in the fourth or sixth aspect. Optionally, the communication system may also include other devices, without limitation.

[0045] Ninthly, a computer-readable storage medium is provided for storing a computer program or instructions that, when executed, cause the methods performed by the terminal device or network device in the above aspects to be implemented.

[0046] In a tenth aspect, a computer program product containing instructions is provided, which, when the computer program or instructions are run on a computer, causes the methods described in the above aspects to be implemented.

[0047] Eleventhly, a chip system is provided, including a processor and an interface, wherein the processor is configured to call and execute instructions from the interface to enable the chip system to implement the methods described above. Attached Figure Description

[0048] Figure 1A Transparent satellite architecture;

[0049] Figure 1B For satellite backhaul architecture;

[0050] Figure 1C It is a regenerable star architecture;

[0051] Figure 2 A flowchart for the initial registration of a UE with the core network;

[0052] Figure 3 A flowchart for non-initial UE registration;

[0053] Figure 4 A schematic diagram illustrating the detection of PDCCH during non-initial registration of a UE;

[0054] Figure 5A and Figure 5B Two schematic diagrams illustrating the detection of PDCCH during small packet transmission for the UE;

[0055] Figure 6 A flowchart illustrating the first communication method provided in this application embodiment;

[0056] Figure 7This is a schematic diagram illustrating that the first duration includes a second duration and a third duration in an embodiment of this application;

[0057] Figure 8 This is a schematic diagram of the detection of PDCCH during initial registration of the UE in an embodiment of this application;

[0058] Figure 9 This is a schematic diagram of a UE detecting PDCCH during non-initial registration in an embodiment of this application;

[0059] Figure 10 A flowchart illustrating the second communication method provided in this application embodiment;

[0060] Figure 11 This is a schematic diagram illustrating the detection of PDCCH by the UE when performing small packet transmission in an embodiment of this application.

[0061] Figure 12 A flowchart illustrating the third communication method provided in the embodiments of this application;

[0062] Figure 13 This is a schematic diagram illustrating the detection of PDCCH by the UE when performing small packet transmission in an embodiment of this application.

[0063] Figure 14 A schematic diagram of an apparatus provided in an embodiment of this application;

[0064] Figure 15 This is a schematic diagram of another device provided in an embodiment of this application. Detailed Implementation

[0065] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the embodiments of this application will be further described in detail below with reference to the accompanying drawings.

[0066] In this application embodiment, the number of nouns, unless otherwise specified, refers to "singular nouns or plural nouns," that is, "one or more." "At least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. For example, A / B means: A or B. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c means: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0067] The ordinal numbers such as "first" and "second" mentioned in the embodiments of this application are used to distinguish multiple objects, and are not used to limit the size, content, order, timing, priority, or importance of the multiple objects. Furthermore, the numbering of steps in the various embodiments described in this application is only to distinguish different steps and is not used to limit the order in which the steps are performed.

[0068] The following explanations of some terms or concepts used in the embodiments of this application are provided to facilitate understanding by those skilled in the art.

[0069] In this application embodiment, the terminal device is a device with wireless transceiver function, which may be a fixed device, a mobile device, a handheld device (e.g., a mobile phone), a wearable device, an in-vehicle device, a satellite terminal device, or a wireless device (e.g., a communication module, a modem, or a chip system, etc.) built into the above devices. The terminal devices are used to connect people, things, and machines, and can be widely used in various scenarios, including but not limited to the following: satellite communication scenarios, sensing scenarios, cellular communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, machine-to-machine / machine-type communications (M2M / MTC) communication, Internet of Things (IoT), virtual reality (VR), augmented reality (AR), industrial control, self-driving, remote medical care, smart grid, smart furniture, smart office, smart wearables, smart transportation, smart city, drones, robots, and terminal devices for indoor commercial scenarios (such as mobile phone screen mirroring, file sharing, and mobile phone to VR glasses). When the terminal equipment is applied to V2X, it can also be called a V2X device, such as a smart car, digital car, unmanned car, driverless car, pilotless car, or automobile, self-driving car, or autonomous car, pure electric vehicle (EV), hybrid electric vehicle (HEV), range-extended electric vehicle (REEV), plug-in hybrid electric vehicle (PHEV), new energy vehicle, or roadside unit (RSU). The terminal equipment can also be a device used in D2D communication, such as an electricity meter or water meter.

[0070] Furthermore, in this embodiment of the application, the terminal device can also be a terminal device in an Internet of Things (IoT) system. IoT is an important component of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network of human-machine interconnection and object-to-object interconnection.

[0071] The various terminal devices described above, if located in a vehicle (e.g., placed inside or installed inside a vehicle), can all be considered in-vehicle terminal devices, also known as on-board units (OBUs). The terminal device of this application can also be an in-vehicle module, in-vehicle component, in-vehicle chip, or in-vehicle unit built into a vehicle as one or more components or units. The vehicle can implement the methods of this application through the built-in in-vehicle module, in-vehicle component, in-vehicle chip, or in-vehicle unit.

[0072] The terminal equipment may sometimes be referred to as UE, terminal, access station, UE station, remote station, wireless communication equipment, or user equipment, etc.

[0073] In this application embodiment, the communication device used to implement the terminal device function can be the terminal device itself, or it can be a device capable of supporting the terminal device in implementing the function, such as a chip system. This device can be installed in the terminal device. In the technical solutions provided in this application embodiment, the terminal device is used as an example to describe the technical solutions provided in this application embodiment. Furthermore, for ease of description, the terminal device in this application embodiment is described using a UE as an example.

[0074] The network devices in this application embodiment include, for example, access network devices (or access network elements) and / or core network devices (or core network elements). The access network devices are devices with wireless transceiver capabilities, used to communicate with the terminal devices. The access network devices include, but are not limited to, base stations (base transceiver stations (BTS), Node B, evolved Node B (eNodeB) / eNB, or the next generation Node B (gNodeB) / gNB), transmission reception points (TRPs), base stations evolved from the 3rd generation partnership project (3GPP), access nodes in wireless fidelity (Wi-Fi) systems, wireless relay nodes, wireless backhaul nodes, etc. The base stations can be: macro base stations, micro base stations, pico base stations, small cells, relay stations, etc. Multiple base stations can support networks using the same access technology or networks using different access technologies. A base station can contain one or more co-located or non-co-located transmission and reception points. The access network equipment can also be a radio controller, centralized unit (CU), and / or distributed unit (DU) in a cloud radioaccess network (CRAN) scenario. The access network equipment can also be a server, etc. For example, the network equipment in V2X technology can be a roadside unit (RSU). The following description uses a base station as an example to illustrate the access network equipment. A base station can communicate with a terminal device, or it can communicate with a terminal device through a relay station. A terminal device can communicate with multiple base stations in different access technologies. The core network equipment is used to implement functions such as mobility management, data processing, session management, policy and billing. The names of the equipment implementing core network functions may differ in systems using different access technologies; this application does not limit this.Taking the 5th generation (5G) mobile communication technology system as an example, the core network equipment includes, for example, access and mobility management function (AMF), session management function (SMF), policy control function (PCF), or user plane function (UPF), etc.

[0075] In the CU-DU architecture, access network equipment can include centralized units (CU) and distributed units.

[0076] One or more logical network elements, such as distributed unit (DU), control plane (CP), user plane (UP), or radio unit (RU). CU and DU can be separate entities or included in the same network element, such as a baseband unit (BBU). RU can be included in radio frequency equipment or radio frequency units, such as remote radio unit (RRU), active antenna unit (AAU), or remote radio head (RRH).

[0077] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an open RAN (ORAN) system, CU can also be called open CU (open CU, O-CU), DU can also be called open DU (open DU, O-DU), CU-CP can also be called open CU-CP (open CU-CP, O-CU-CP), CU-UP can also be called open CU-UP (open CU-CP, O-CU-UP), and RU can also be called open RU (open RU, O-RU). For ease of description, the embodiments of this application use CU, CU-CP, CU-UP, DU, and RU as examples. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in the embodiments of this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0078] Optionally, in various embodiments of this application, if the network device is a distributed architecture, such as the network device including CU and DU, or including CU-CP, CU-UP and DU, then the network device sends information to the UE, specifically the DU included in the network device sends information to the UE; the network device receives information from the UE, specifically the DU included in the network device receives information from the UE.

[0079] In this application embodiment, the communication device used to implement the network device function can be a network element, or a network device, or a device capable of supporting the network device to implement the function, such as a chip system. This device can be installed in the network device. In the technical solutions provided in this application embodiment, the technical solutions provided in this application embodiment are described using the example of a network device as the device used to implement the network device function (for example, the device used to implement the access network device function is an access network device or an access network element, and the device used to implement the core network device function is a core network device or a core network element).

[0080] Please refer to Figures 1A to 1C This diagram illustrates several network architectures for NTN. Depending on the deployment scenario of satellite and terrestrial networks, NTN network architectures can include transparent satellite architecture, satellite backhaul architecture, and regenerator satellite architecture. An architecture where the UE connects to the terrestrial access network via satellite can be called a transparent satellite architecture (e.g., Figure 1A The architecture where the UE connects to the terrestrial access network and then connects to the terrestrial network via satellite can be called a satellite backhaul architecture, a wireless backhaul architecture, or a satellite wireless backhaul architecture (e.g.) Figure 1B Additionally, an architecture that places access network elements on a satellite (or where the satellite has the function of access network elements) is called a regenerative satellite architecture or regenerative star architecture (e.g., Figure 1C ).

[0081] exist Figure 1A In this system, the network elements used for transmitting services (such as access network elements and / or core network elements) are all located on the ground. The UE accesses the network through the access network elements located on the ground via satellite, and the satellite has a pass-through function.

[0082] exist Figure 1B In this system, the access network elements are located on the ground. The UE communicates with the satellite through the ground access network and then connects to the ground network through the satellite.

[0083] exist Figure 1CIn this configuration, access network elements are located on satellites, or the underlying processing modules of access network elements are located on satellites, or the satellite has some or all of the functions of the access network elements. Besides the access network elements, other network elements used for transmitting services (such as core network elements) are located on the ground. Alternatively, some or all of the network elements in the core network can also be located on satellites, or the satellite can have some or all of the functions of the network elements in the core network.

[0084] In NTN, after a UE sends information to the network, it can wait for a response. Some responses are sent by access network elements, while others are sent by core network elements. In a regenerating satellite architecture, the access network elements are deployed on the satellite, while the core network elements are located on the ground. For responses from core network elements, the transmission delay is relatively long. Furthermore, the UE checks the PDCCH after sending a signal to wait for a network response, resulting in significant power consumption. Several possible scenarios are described below. In these scenarios, if the embodiments of this application are applied to a 5G system, the core network element can be an AMF or UPF; or, if the embodiments of this application are applied to a 4G system, the core network element can be a mobility management entity (MME) or a serving gateway (S-GW); or, if the embodiments of this application are applied to a 6G system or other communication systems, the core network element can be a corresponding network element within that communication system.

[0085] 1. Scenario A: The scenario where a UE establishes a connection with a core network element when transitioning from the Radio Resource Control (RRC) idle state to the RRC connected state. Scenario A is further divided into two scenarios: Scenario 1 and Scenario 2. Scenario 1 is the scenario where the UE initially registers with the core network, while Scenario 2 is the scenario where the UE does not initially register.

[0086] (1) Scenario 1: The scenario of UE initial registration with the core network. Please refer to... Figure 2 This is the flowchart for Scenario 1.

[0087] S201. The UE establishes an RRC connection with the access network element. For example, the UE performs random access to establish an RRC connection with the access network element.

[0088] S202, the UE sends a registration request to the core network element. The core network element receives the registration request. This registration request is used to request registration with the core network element.

[0089] For example, after establishing an RRC connection with an access network element, such as after receiving message 4 (Msg4) during the random access procedure, the UE can send a registration request to the core network element. The UE can send an RRC connection completion message, which includes a NAS message, and this NAS message can include the registration request. After receiving the RRC connection completion message, the access network element can forward the registration request to the core network element.

[0090] S203. The core network element sends an authentication request to the UE. The UE receives the authentication request. For example, the authentication request can be forwarded to the UE through an access network element. This authentication request can be used to authenticate the UE to determine its legitimacy.

[0091] S204. The UE sends an authentication response to the core network element. Correspondingly, the core network element receives the authentication response.

[0092] S205. The core network element sends a NAS security command to the UE. The UE receives the NAS security command accordingly. This NAS security command can be used to configure and / or activate NAS layer security mechanisms, such as encryption mechanisms.

[0093] S206. The UE sends a NAS security command response to the core network element. Correspondingly, the core network element receives the NAS security command response.

[0094] S207. The core network element sends a registration acceptance message to the access network element. Correspondingly, the access network element receives the registration acceptance message.

[0095] For example, if the core network element determines that the UE is legitimate through authentication, the core network element can send the registration acceptance message. However, if the UE is illegitimate, and / or the UE cannot complete the NAS security response, the core network element may not send the registration acceptance message; for example, it may send a registration rejection message.

[0096] S208, the UE and the access network element complete the AS layer security establishment.

[0097] For example, the UE and core network elements can establish AS-layer security mechanisms, such as encryption mechanisms.

[0098] S209. The access network element sends an RRC reconfiguration message to the UE. The UE receives this RRC reconfiguration message. This message can configure relevant parameters for the UE, such as configuring connected mode discontinuous reception (C-DRX), allowing the UE to save power.

[0099] S210, the UE sends an RRC reconfiguration complete message to the access network element. Correspondingly, the access network element receives this RRC reconfiguration complete message.

[0100] S211. The access network element sends a registration acceptance message to the UE. The UE then receives this registration acceptance message. At this point, the UE has registered with the core network element.

[0101] As can be seen from the above process, the UE and core network elements may have multiple interaction processes. For example, before the UE has a power-saving mechanism (e.g., C-DRX is configured), the UE and core network elements have three interaction processes. During these three interaction processes, after sending messages (e.g., registration request, authentication response, or NAS security command response), the UE needs to continuously monitor the PDCCH to receive corresponding messages (e.g., authentication request, NAS security command, or messages used to establish AS layer security mechanisms). The messages that the UE is waiting for require interaction between the access network element and the core network element. If there is a large time delay between the access network element and the core network element (e.g., ...), ... Figure 1A The transparent satellite architecture shown or Figure 1C The regenerating star architecture shown or Figure 1B In the wireless backhaul architecture shown, the UE needs to wait a long time to receive a response. Continuous monitoring of the PDCCH by the UE obviously leads to significant power consumption.

[0102] (2) Scenario 2, the scenario where the UE is not initially registered. Please refer to... Figure 3 This is the flowchart for scenario 2.

[0103] S301. The UE establishes an RRC connection with the access network element. For example, the UE performs random access to establish an RRC connection with the access network element.

[0104] S302, the UE sends a service request to the core network element. The core network element then receives the service request. This service request is used to request the corresponding service.

[0105] For example, after establishing an RRC connection with an access network element, such as after receiving Msg4 during the random access procedure, the UE can send a service request to the core network element. The UE can send an RRC connection completion message, which includes a NAS message, and this NAS message can include the service request. Upon receiving the RRC connection completion message, the access network element can forward the service request to the core network element.

[0106] S303. The core network element sends a context establishment request to the access network element. Correspondingly, the access network element receives the context establishment request. This context establishment request can request the establishment of the UE's context.

[0107] S304. The access network element sends a context establishment complete message to the core network element. Correspondingly, the core network element receives this context establishment complete message. For example, this context establishment complete message may include the UE's context.

[0108] S305, UE and access network elements complete AS layer security establishment.

[0109] For example, the UE and core network elements can establish AS-layer security mechanisms, such as encryption mechanisms. S304 and S305 can be executed simultaneously, or S304 can be executed before or after S305.

[0110] S306. The access network element sends an RRC reconfiguration message to the UE. The UE receives this RRC reconfiguration message. This message can configure relevant parameters for the UE, such as configuring C-DRX, to save power for the UE.

[0111] S307. The UE sends an RRC reconfiguration complete message to the access network element. Correspondingly, the access network element receives the RRC reconfiguration complete message.

[0112] S308. The core network element sends a service accept message to the access network element. Correspondingly, the access network element receives the service accept message. This service accept message indicates that the core network element can provide the UE with the service requested by the UE. For example, the core network element can send this service accept message after receiving the UE's context.

[0113] In this embodiment, the core network element can execute S308 after receiving the context establishment completion message in S304. The execution order between S308 and S305 to S307 is not restricted.

[0114] S309. The access network element sends a service acceptance message to the UE. Correspondingly, the UE receives the service acceptance message.

[0115] As can be seen from the above process, after sending a service request, the UE needs to continuously monitor the PDCCH to receive corresponding messages, such as messages used to establish AS layer security mechanisms. The messages the UE waits for require interaction between the access network element and the core network element. If there is a significant time delay between the access network element and the core network element (e.g., ...), ... Figure 1A The transparent satellite architecture shown or Figure 1CThe regenerating star architecture shown or Figure 1B In the wireless backhaul architecture shown, the UE needs to wait a long time to receive the message. Continuous monitoring of the PDCCH by the UE obviously leads to significant power consumption.

[0116] Please refer to Figure 4 ,for Figure 3 A schematic diagram of scenario 2 shown. Figure 4 This can correspond to either a regenerator architecture or a wireless backhaul architecture. Specifically, if... Figure 4 In the corresponding wireless backhaul architecture, satellite backhaul is involved between the UE and the access network elements. According to Figure 4 As can be seen, after receiving Msg4 (also known as a contention resolution message), the UE can send a service request, and the UE needs to maintain detection of the PDCCH, for example, detecting the PDCCH scrambled with C-RNTI. The access network element needs to interact with the core network element to obtain the UE's context before sending messages to the UE to establish AS-layer security mechanisms. Only then can C-DRX be configured for the UE via RRC reconfiguration messages, allowing the UE to save power. However, after the UE sends the service request, a significant portion of the UE's detection time is actually invalid detection time, increasing the UE's power consumption.

[0117] 2. Scenario B: UE performs small packet transmission. This small packet transmission could be, for example, small data transmission (SDT) in a 5G new radio (NR) system, early data transmission (EDT) in a long term evolution (LTE) system, or other small packet transmission technologies.

[0118] The UE can transmit uplink small packets via message 3 (Msg3) during the random access procedure. After receiving Msg3, the access network element can send Msg4 to the UE. Normally, the access network element can send an RRC release message to the UE to release it. However, the access network element may not be certain whether the core network element also has downlink small packet data to send to the UE. Therefore, the access network element may not send the RRC release message initially, but instead interact with the core network element. If there is still downlink small packet data, the access network element can send the downlink small packet data from the core network element to the UE; if there is no downlink small packet data, the access network element then sends the RRC release message to the UE. Therefore, for the UE, after sending Msg3 or receiving Msg4, it needs to continuously monitor the PDCCH to receive downlink small packet data or the RRC release message. The message the UE is waiting for requires interaction between the access network element and the core network element. If there is a significant time delay between the access network element and the core network element (e.g., ...), ... Figure 1C The regenerating star architecture shown or Figure 1B In the wireless backhaul architecture shown, the UE needs to wait a considerable amount of time to receive downlink small packet data or RRC release messages. It can be assumed that the UE is performing invalid detection for a significant portion of the detection time. Furthermore, continuous detection of the PDCCH by the UE obviously leads to substantial power consumption.

[0119] Please refer to Figure 5A This is a schematic diagram of scenario B. Figure 5A Take the regenerating star architecture as an example. According to... Figure 5A As can be seen, after receiving Msg4 (also known as a contention resolution message), the UE needs to maintain PDCCH detection, for example, detecting the PDCCH scrambled with the cell-radio network temporary identifier (C-RNTI). The access network element needs to interact with the core network element before it can send downlink small packet data or RRC release messages to the UE. After receiving Msg4, a significant portion of the UE's detection time is actually invalid, increasing the UE's power consumption. Furthermore... Figure 5A In this context, after sending the preamble, the UE can wait for the RTT before detecting the RAR. For example, after sending the preamble, the UE waits for the RTT, the RAR window begins, and the UE can receive the RAR within the RAR window. Similarly, after sending Msg3, the UE can wait for the RTT before detecting the PDCCH, for example, waiting for the RTT before starting the contention resolution timer. Here, the RTT is, for example, the round-trip time between the UE and the access network element.

[0120] Please refer to this again. Figure 5B This is another schematic diagram of scenario B. Figure 5B Take the wireless backhaul architecture as an example. According to... Figure 5B As can be seen, after receiving Msg4 (also known as a contention resolution message), the UE needs to maintain PDCCH monitoring, for example, monitoring the PDCCH scrambled with C-RNTI. The access network element needs to interact with the core network element before it can send downlink small packet data or RRC release messages to the UE. Therefore, a significant portion of the detection time after receiving Msg4 is actually invalid detection time, increasing the UE's power consumption. Furthermore... Figure 5B In this context, after sending the preamble, the UE can wait for the RTT before detecting the RAR; and after sending Msg3, the UE can wait for the RTT before detecting the PDCCH, for example, waiting for the RTT before starting the contention resolution timer. Additionally... Figure 5B In this context, the UE can detect RAR without waiting for RTT after sending the preamble; and the UE can detect PDCCH without waiting for RTT after sending Msg3, for example, the contention resolution timer can be started after sending Msg3.

[0121] Therefore, in this embodiment, after the UE sends the first message or receives a corresponding message (e.g., Msg4), it will only start detecting the PDCCH when the first duration arrives, and will not detect the PDCCH during the first duration. The first duration is determined based on the round-trip time between the access network element and the core network element. For example, for a regenerable satellite architecture, the first duration takes into account the round-trip time between the satellite and the ground. This means that the UE can not detect the PDCCH during the transmission of information replied by the network, but can detect the PDCCH when the information is about to arrive at the UE to receive the information. Thus, this embodiment does not affect the UE's reception of information from the network and reduces the time the UE spends detecting the PDCCH, thereby saving the UE's power consumption.

[0122] The technical solutions provided in this application can be applied to fourth-generation (4G) mobile communication systems, such as LTE systems, or to 5G systems, such as NR systems, or to next-generation mobile communication systems or other similar communication systems, such as sixth-generation (6G) mobile communication systems, or to existing satellite mobile communication systems. No specific limitations are imposed. The technical solutions provided in this application can be used in NTN, or they can be applied to other scenarios. For example, in scenarios where the transmission delay between access network elements and core network elements is long, whether it is an NTN or a terrestrial network, the technical solutions of this application can be applied.

[0123] The embodiments of this application can be applied to Figure 1A or Figure 1B or Figure 1CThe scenario shown can also be used in other scenarios, such as any scenario where the transmission delay between access network elements and core network elements is long.

[0124] The method provided in the embodiments of this application is described below with reference to the accompanying drawings. In various embodiments of this application, "detecting PDCCH" can also be replaced with "monitoring PDCCH". In the accompanying drawings corresponding to various embodiments of this application, all steps indicated by dashed lines are optional steps. The various embodiments herein can be applied to... Figure 1A or Figure 1B or Figure 1C The network architecture shown, i.e., in the various embodiments of this document, includes a communication link between the access network element serving the UE and the core network element serving the UE, which may include a link between a satellite and a ground station. For example, the UE described in the various embodiments of this document may be... Figure 1A or Figure 1B or Figure 1C The UE shown; the access network elements described in the various embodiments of this document can be Figure 1A or Figure 1B The access network element shown, or Figure 1C The regenerating satellite shown (or the access network element is located on the regenerating satellite, or the function of the access network element is deployed on the regenerating satellite); the core network element described in the various embodiments of this document can be Figure 1A or Figure 1B or Figure 1C The core network elements are shown. Among them, Figure 1A or Figure 1B or Figure 1C The core network elements shown may include some or all of the network elements within the core network. For example, the first core network element described in the various embodiments of this document may include... Figure 1A or Figure 1B or Figure 1C Among the core network elements shown.

[0125] This application provides a first communication method, please refer to... Figure 6 Here is a flowchart of the method.

[0126] S601, the UE sends the first message. Correspondingly, the first core network element receives the first message.

[0127] In this embodiment, the first message can be a non-access stratum (NAS) message. The UE can send the first message to an access network element, which can then forward it to a first core network element. Specifically, if this embodiment is applied to a 5G system, the first core network element is, for example, an AMF; or, if this embodiment is applied to a 4G system, the first core network element is, for example, an MME; or, if this embodiment is applied to a 6G system or other communication systems, the first core network element can be a corresponding core network element within that system.

[0128] This application embodiment can be a scenario where a UE establishes a connection with a first core network element when entering the RRC connected state from the RRC idle state. This application embodiment can be a scenario of initial UE registration or a non-initial registration scenario. For example, if this application embodiment is a scenario of initial registration, the first message can have one or more of the following uses: for requesting registration with the first core network element, for sending the authentication response of the terminal device to the first core network element, or for sending a NAS security command response to the first core network element. Optionally, the first message is a NAS message sent by the UE to the core network before AS security activation. Or, if the initial registration process involves other interactions between the UE and the core network element, the first message can also be a message sent by the UE during those interactions. Specifically, if the first message is used to request registration with the first core network element, optionally, the first message is, for example, a registration request; if the first message is used to respond to the authentication result of the terminal device to the first core network element, optionally, the first message is, for example, an authentication response; if the first message is used to respond to the NAS security configuration to the first core network element, optionally, the first message is, for example, a NAS security command response.

[0129] For example, if the embodiments of this application involve a non-initial registration scenario, the first message can be used to request services from the first core network element. Optionally, the first message can be, for example, a service request. Optionally, the first message can be a NAS message sent by the UE to the core network before the UE's AS security activation. Alternatively, if other interactions between the UE and the core network element are involved in the non-initial registration process, the first message can also be a message sent by the UE during those interactions.

[0130] Optionally, before S601, the method may also include S602, whereby the UE establishes an RRC connection with the access network element, for example, the UE performs random access with the access network element. After the UE completes the random access, S601 can be executed; for example, the first message can be considered as message 5 (Msg5).

[0131] During the establishment of an RRC connection between the UE and the access network element, the processing methods may differ depending on the network architecture. For example, for a transparent satellite architecture or a regenerable satellite architecture, after sending message 1 (Msg1) or Msg3 in the random access process, the UE may delay for a fourth duration before starting to detect the PDCCH. Optionally, after sending Msg1, the PDCCH detected by the UE may be a radio access (RA)-RNTI scrambled PDCCH; after sending Msg3, the PDCCH detected by the UE may be a temporary cell (TC)-RNTI scrambled PDCCH. Msg1 may be, for example, a random access request, such as a preamble; Msg3 may be, for example, an RRC connection establishment request. For example, the UE may start detecting the PDCCH when the fourth duration arrives after Msg1 or Msg3 has been sent, but may not detect the PDCCH within the fourth duration. Optionally, after sending Msg3, the UE may not detect the TC-RNTI scrambled PDCCH within the fourth duration. The fourth duration can be determined based on the round-trip time between the UE and the access network element. Optionally, this fourth duration can be the same as the third duration, which will be introduced later, for example, using the same parameter or derived from the same parameter, such as calculated by the UE using its location and / or ephemeris information. Since the UE needs to wait for a reply from the access network element after sending Msg1 or Msg3 (for example, waiting for message 2 (Msg2) or Msg4 from the access network element, where Msg2 is, for example, a random access response (RAR)), and Msg2 or Msg4 is sent by the access network element without the need for interaction between the access network element and the core network element, the UE's waiting time for Msg2 or Msg4 does not need to consider the delay between the access network element and the core network element, but only the delay between the UE and the access network element. Therefore, in this embodiment, the UE can wait a fourth time interval after sending Msg1 or Msg3 before starting to detect the PDCCH. This means the UE can refrain from detecting the corresponding RNTI-scrambled PDCCH during the transmission of information from the access network element, and can start detecting the PDCCH to receive the information after the earliest expected arrival time of that information. Thus, this embodiment does not affect the UE's reception of information from the access network element, and reduces the UE's PDCCH detection time, thereby saving UE power consumption.

[0132] For the wireless backhaul architecture, after the UE sends Msg1 or Msg3, due to the relatively small transmission delay between the UE and the access network element, it is not necessary to delay for a fourth duration; instead, it can detect the PDCCH in the traditional way. Specifically, the UE can directly detect the PDCCH after sending Msg1 or Msg3, for example, it can start detecting the PDCCH as soon as Msg1 or Msg3 is sent; or, the UE can delay by a corresponding offset after sending Msg1 or Msg3 before starting to detect the PDCCH, and this offset can be less than the fourth duration.

[0133] S603. When or after the first duration following the completion of the first message transmission, the UE detects the PDCCH. Optionally, the PDCCH can be a C-RNTI scrambled PDCCH.

[0134] Optionally, after the UE sends the first message, it does not detect the PDCCH within the first duration, but starts detecting the PDCCH when or after the first duration has elapsed.

[0135] For example, the start time of the first duration could be the time when the first message is sent, the time when the UE starts sending the first message, or the time when the first offset arrives after the first message is sent. This first offset could be, for example, the UE's processing time.

[0136] Optionally, the UE can determine the first duration using a timer, for example, a second timer. For instance, the UE can start the second timer at the beginning of the first duration, with the second timer's duration being the first duration. The second timer expires when the first duration has elapsed. During the second timer's operation, the UE does not detect the PDCCH. For example, the UE detects the PDCCH when the second timer expires, after it expires, or after it has expired. Alternatively, the UE can reset the second timer when it expires or after it has expired, for example, by resetting its value to the first duration so that the second timer can be used again next time. Or, the UE can determine the first duration using other methods instead of the second timer, such as a counter, etc. This embodiment does not limit this approach.

[0137] During the first duration, the UE may not detect the PDCCH. For example, during the first duration, the UE may not detect the C-RNTI scrambled PDCCH. Optionally, the first duration may be determined based on the round-trip time (RTT) between the access network element and the core network element, where the core network element may include a first core network element; or, the first duration may be determined based on the round-trip time between the access network element and a ground gateway station, where the access network element can communicate with the core network element through the gateway station, which may, for example, refer to... Figure 1C ; optional Figure 1B The scenario shown can also include gateway stations, for example, satellites communicating with ground core network elements through ground gateway stations.

[0138] Optionally, in the regenerator architecture, the first duration is determined based on the round-trip time between the access network element and the core network element. This may include determining the first duration based on the round-trip time between the UE and a ground gateway station (the UE communicates with this gateway station via satellite) or based on the round-trip time between the UE and the core network element. The access network element serving the UE can communicate with the core network element serving the UE through this gateway station. For this network architecture, please refer to [reference needed]. Figure 1C Alternatively, in a wireless backhaul architecture, the initial duration can be determined based on the round-trip delay between the access network element and the core network element, for example, by referring to... Figure 1B In the wireless backhaul architecture, since both the UE and the access network element are located on the ground, communication between the UE and the access network element does not pass through a satellite, therefore the latency between the UE and the access network element can be ignored. Alternatively, in a transparent satellite architecture, the first duration can be determined based on the round-trip time between the UE and the access network element, or the first duration can be determined based on the UE's TA and K. mac This is confirmed; the network architecture can be referenced. Figure 1A .

[0139] Optionally, due to the movement of the satellite, the first duration may vary over time, and the first duration determined by the UE may be related to the current time and / or ephemeris time.

[0140] In summary, regardless of the architecture, the first duration takes into account the round-trip time of the first message sent by the UE during transmission between the satellite and the ground network element. This is equivalent to the period between the UE receiving the first message from the network and, assuming the network immediately replies, receiving the reply. Within this first duration, the UE is highly unlikely to receive a reply from the network, therefore the UE does not need to detect the PDCCH. However, when or after the first duration expires, the network reply may reach the UE, allowing the UE to begin detecting the PDCCH to receive the information. Thus, the embodiments of this application neither affect the UE's reception of information from the network nor reduce the time the UE spends detecting the PDCCH, thereby saving UE power consumption.

[0141] The duration of the first step may vary depending on the network architecture.

[0142] Optionally, for a regenerator architecture, the first duration may include a second duration and a third duration. The second duration may be determined based on the round-trip time between the access network element and the core network element; or, the second duration may be determined based on the round-trip time between the access network element and a ground gateway station; or, the second duration may be determined based on the round-trip time between the satellite and a ground gateway station; or, the second duration may be determined based on the round-trip time between the satellite and a core network element. For example, the second duration may include the round-trip time between the access network element and the core network element, or the second duration may include the round-trip time between the access network element and a ground gateway station, or the second duration may include the round-trip time between the satellite and a ground gateway station, or the second duration may include the round-trip time between the satellite and a core network element.

[0143] The third duration can be determined based on the round-trip time delay between the UE and the access network element, the round-trip time delay between the UE and the satellite, or the UE's time advance (TA). Optionally, the UE can determine the third duration based on one or more of the following: its location, ephemeris information provided by the access network element, or the current time. Specifically, based on ephemeris information and the current time, the UE can determine the current location of the satellite serving the UE (e.g., the satellite where the access network element is located), and thus determine the third duration based on the UE's location and the satellite's location. For example, see [reference needed]. Figure 7 This is an example of the first duration. Figure 7 Taking the second duration as an example, which is the round-trip delay between the access network element and the ground gateway station.

[0144] Optionally, for a wireless backhaul architecture, the first duration can be a single unit. For example, the first duration can be determined based on the round-trip time between the access network element and the satellite, and the round-trip time between the satellite and the core network element. The core network element may include a first core network element, which in various embodiments of this application is, for example, an AMF or UPF in a 5G system, or an MME or S-GW in a 4G system. For example, the first duration includes the round-trip time between the access network element and the satellite, and the round-trip time between the satellite and the core network element.

[0145] Optionally, for a transparent satellite architecture, the first duration can also be a single unit. For example, the first duration can be determined based on the round-trip time between the UE and the access network element.

[0146] The UE can determine the first duration in different ways. Optionally, due to satellite movement, the first duration can change over time, and the first duration determined by the UE can be related to the current time and / or ephemeris time. Alternatively, the first duration can also be a fixed value.

[0147] As a first optional implementation for the UE to determine the first duration, the UE can receive a first parameter. The UE can determine the first duration based on the first parameter; for example, the UE can calculate the duration based on the first parameter, and this duration can be used as the first duration. The first parameter can come from an access network element, for example, the access network element can send the first parameter via broadcast or unicast. Taking the access network element broadcasting the first parameter as an example, the first parameter may be included in system information (SI), or it may also be included in other broadcast information. In this implementation, the access network element only needs to send the parameter to the UE, which is relatively simple for the access network element and can reduce its burden. Alternatively, the first parameter can also come from a core network element, such as a first core network element or other core network elements. The UE can obtain the first parameter from the core network element in advance, and then determine the first duration based on the first parameter; for example, the UE can determine the first duration by combining its location information and the first parameter. Having the core network element indicate the first parameter can reduce the amount of information broadcast by the access network element, making the implementation simpler.

[0148] The first parameter can be used to determine the first duration. Optionally, for a radio backhaul architecture, the first parameter may include the coefficients of an Nth-order function fitted based on the change in the sum of the round-trip delay between the access network element and the satellite, and the round-trip delay between the satellite and the core network element over time; or, the first parameter may also include the coefficients of an Nth-order function fitted based on the change in the time required for the UE to delay listening to the PDCCH after sending the NAS message before AS security activation. Here, N is, for example, 2 or 3. Taking the fitting using a quadratic function (i.e., N=2) as an example, the first parameter may include one or more of the following: a second parameter, a third parameter, or a fourth parameter. Here, the second parameter can be a constant term of the round-trip delay change, the third parameter can be a coefficient of a linear term of the round-trip delay change, and the fourth parameter can be a coefficient of a quadratic term of the round-trip delay change. For example, the first duration determined at time t can satisfy the following relationship:

[0149] First duration (t) = Second parameter + Third parameter × (tt) epoch )+fourth parameter×(tt) epoch ) 2

[0150] Formula (1)

[0151] Where t is the current time or the time at which the first duration is determined (e.g., calculated), such as the time when the first message is sent;

[0152] t epoch This indicates the ephemeris time, which is, for example, the reference time provided by the ephemeris information.

[0153] Optionally, for the regenerator architecture, the first parameter may include the coefficients of an Nth-order function fitted based on the round-trip delay from the ground cell reference point (which can be the nadir point or the farthest point of the cell) to the satellite, and the sum of the round-trip delays between the satellite and the core network elements over time; or, the first parameter may include the coefficients of an Nth-order function fitted based on the time the UE needs to delay listening to the PDCCH after sending the NAS message before AS security activation. For details, refer to the method for obtaining the first parameter in the radio backhaul architecture.

[0154] As previously mentioned, for a regenerating satellite architecture, the first duration can include a second duration and a third duration. Optionally, one way to determine the first duration using the first parameter is that the first parameter can be used to determine the second duration, and the first duration can be further determined based on the second duration. For example, the first duration can be determined based on the second duration and the third duration. The first parameter can include the coefficients of an Nth-order function fitted based on the time-varying round-trip delay between the satellite and the ground gateway. The first parameter may include, for example, one or more of the following: a second parameter, a third parameter, or a fourth parameter. The second parameter can be a constant term in the variation of the second duration, the third parameter can be a coefficient of a linear term in the variation of the second duration, and the fourth parameter can be a coefficient of a quadratic term in the variation of the second duration. For example, the second duration determined at time t can satisfy the following relationship:

[0155] Second duration (t) = Second parameter + Third parameter × (tt) epoch )+fourth parameter×(tt) epoch ) 2

[0156] Formula (2)

[0157] Where t represents the current time, or the time at which the second duration is determined (e.g., calculated), or the time at which the first duration is determined (e.g., calculated), for example, t is the time when the first message is sent; t epoch This indicates the ephemeris time, which is, for example, the reference time provided by the ephemeris information.

[0158] Alternatively, the second duration can be calculated by referring to the method used in transparent satellite architectures to calculate the round-trip delay from the satellite to the ground gateway. For example, it can be calculated using the round-trip delay K from the satellite to a given reference point (RP). mac The round-trip time from the satellite to the RP is calculated. The round-trip time from the satellite to the RP can be characterized by one or more of the following: timing advance common (TACommon), timing advance common drift (TACommonDrift), or timing advance common drift variation (TACommonDriftVariation). Optionally, the second duration can satisfy the following relationship:

[0159] Second duration (t) = TACommon + TACommonDrift × (tt) epoch )+TACommonDriftVariation×(ttepoch ) 2

[0160] +K mac

[0161] Formula (3)

[0162] The first duration can be determined based on the second and third durations. For example, the first duration determined at time t can satisfy the following relationship:

[0163] First duration (t) = Second duration (t) + Third duration (t)

[0164] Formula (4)

[0165] The method for determining the third duration can be found in the previous text. Alternatively, the third duration at time t can also be the timing advance of the UE at time t.

[0166] As a second optional implementation for the UE to determine the first duration, the UE can receive information about the first duration, thereby directly determining the first duration based on this information without having to perform a calculation process. If the first duration is variable, the UE can receive the first duration information once or multiple times, for example, periodically. This implementation reduces the UE's calculation process, simplifies the UE's implementation, and allows the technical solution of this application embodiment to be applied to both high-capacity and low-capacity UEs. This information may come from an access network element, which can send the information via broadcast or unicast. For example, if the access network element broadcasts the information, the information may be included in system information or other broadcast information. Alternatively, the information may come from a core network element, such as a first core network element or other core network elements. Optionally, for a wireless backhaul architecture, the access network element or core network element can send information about the first duration, which the UE receives, and the UE can determine the first duration based on this information. Alternatively, for the regenerator architecture, the access network element or core network element can send information of a first duration, and the UE receives the information of the first duration and can determine the first duration based on the information; or the access network element or core network element can send information of a second duration, and the UE receives the information of the second duration and can determine the second duration based on the information. The UE can then combine the second duration and the third duration to determine the first duration.

[0167] Optionally, the first or second duration configured by the access network element or core network element for the UE can be related to the waiting time the UE needs to wait after sending a NAS message before AS security is activated. For example, the configured first duration can be the waiting time the UE needs to wait after sending a NAS message before AS security is activated. Alternatively, if the access network element or core network element configures a second duration, the UE can combine the second and third durations to determine the waiting time the UE needs to wait after sending a NAS message before AS security is activated. This determined duration can be used as the first duration. This first or second duration may be greater than, less than, or equal to the round-trip time between the access network element and the core network element, but it can still help the UE reduce the time spent detecting the PDCCH, thereby saving energy.

[0168] Optionally, for a transparent satellite architecture, the UE can determine the first duration without relying on the first parameter or receiving the first duration information. For example, the UE can determine the first duration based on factors such as the current time and / or ephemeris time. Optionally, one way for the UE to determine the first duration is to refer to Formulas 3 and 4 above, where the first duration in Formula 4 is the first duration determined by the UE. For example, the UE can use the calculation result of Formula 4 as the first duration. Alternatively, the first duration determined by the UE can be less than or equal to the first duration in Formula 4. For example, the UE can use a duration less than or equal to the calculation result of Formula 4 as the first duration. The reason why the first duration determined by the UE can be less than or equal to the calculation result of Formula 4 is to ensure that the UE and the network can understand the duration in a consistent way, thereby enabling the UE to save energy without affecting the network's implementation. In addition, the second duration in Formula 3 can be regarded as an intermediate amount for the UE to calculate the first duration.

[0169] Under the regenerator architecture, if the second duration is less than or equal to the minimum round-trip time (RTD) between the cell's satellite and the ground gateway or between the satellite and the core network element, the access network element can simply send the corresponding information to the UE upon receiving the response from the core network element, making the process relatively simple. However, for the UE, if the RTD between the UE and the core network element is large (or the RTD between the access network element and the core network element is large), the energy-saving effect on the UE will be relatively limited. Alternatively, if the second duration is greater than the maximum RTD between the cell's satellite and the ground gateway or between the satellite and the core network element, the access network element may delay sending the corresponding information to the UE after receiving the response from the core network element. This ensures that the UE receives the information from the access network element only after it begins detecting the PDCCH, which can achieve greater energy savings for the UE, but the transmission delay may be relatively large. Alternatively, the second duration can be the average latency from the satellite to the ground gateway station or from the satellite to the core network element, or any value between the maximum and minimum latency from the satellite to the ground gateway station or from the satellite to the core network element. This application does not impose any restrictions on this.

[0170] For the wireless backhaul architecture, the UE can determine the first duration based on the first parameter. If the first duration is less than or equal to the minimum round-trip time between the access network element and the core network element, or between the access network element and the ground gateway station, the access network element can simply send the corresponding information to the UE upon receiving the reply from the core network element, which is relatively simple. However, for the UE, if the round-trip time between the UE and the core network element is large (or the round-trip time between the access network element and the core network element is large), the energy-saving effect of the UE is relatively limited. Alternatively, if the first duration is greater than the maximum round-trip time between the access network element and the gateway station of the core network element, or between the access network element and the ground gateway station, the access network element may delay sending the corresponding information to the UE after receiving the reply from the core network element, in order to ensure that the information from the access network element is received only after the UE starts detecting the PDCCH. This can achieve greater energy saving for the UE, but the transmission delay may be relatively large. Alternatively, the first duration can be the average latency between the access network element and the core network element, or the average latency between the access network element and the ground gateway station, or any value between the maximum and minimum latency between the access network element and the core network element, or any value between the maximum and minimum latency between the access network element and the ground gateway station. This application embodiment does not impose any restrictions on this.

[0171] As mentioned above, the first duration or the second duration can be determined based on the round-trip time between the access network element and the core network element, or based on the round-trip time between the access network element and the ground gateway station. The UE can be aware of this; for example, the UE knows the current network architecture and the meaning of the first duration or the second duration. Alternatively, the UE may not be aware of this. For example, the UE may not know the current network architecture, or the UE may know the network architecture but not be aware of the meaning of the first duration or the second duration. In the case where the UE is unaware, the UE can also determine the first duration based on the first parameter, or based on received information (such as information about the first duration or the second duration).

[0172] Optionally, the UE may detect the PDCCH in the manner provided in the embodiments of this application if certain conditions are met, such as detecting the PDCCH when or after the first duration following the completion of the first message transmission; if the conditions are not met, the UE may not detect the PDCCH in the manner provided in the embodiments of this application. If the UE does not detect the PDCCH in the manner provided in the embodiments of this application, then, regardless of whether it is a regenerator architecture or a radio backhaul architecture, the UE may directly detect the PDCCH after sending the first message without delay; or, the UE may delay by a corresponding second offset after sending the first message before starting to detect the PDCCH, and this second offset may be less than the fourth duration.

[0173] This condition may include, for example, one or more of the following: the access network element sends information of a first duration or a second duration; the access network element sends a first parameter; the access network element indicates that there is a time delay (or a significant time delay) between the access network element and the core network element; the UE is located in a regenerator architecture; the UE is located in a radio backhaul architecture; and K is not configured. mac And / or the fifth parameter, K mac =0 and / or the value of the fifth parameter =0, or, K mac =0 and / or The fifth parameter, for example, includes one or more of TACommon, TACommonDrift, or TACommonDriftVariation, and can be used to determine... Taking the fifth parameter, which includes TACommon, TACommonDrift, and TACommonDriftVariation, as an example, when TACommon, TACommonDrift, and TACommonDriftVariation are all 0, the value of the fifth parameter is 0. This represents the round-trip time delay between the satellite and the reference point (RP).

[0174] For example, in a wireless backhaul architecture, if an access network element can indicate that there is a time delay (or a large time delay) between the access network element and the core network element, it is considered to meet the condition, and the UE can use the solution provided in the embodiments of this application accordingly.

[0175] Please refer to Figure 8 This is a schematic diagram of an embodiment of this application. Figure 8 Taking the initial registration of a UE as an example. Figure 8 As can be seen, after sending the registration request, authentication response, and NAS security command response, the UE will not check the PDCCH for the first time period, and will check the PDCCH again when or after the first time period expires. This reduces the UE's invalid detection time and saves the UE's power consumption.

[0176] Please refer to this again. Figure 9 This is another schematic diagram of an embodiment of this application. Figure 9 Taking a UE performing a non-initial registration as an example. According to Figure 9 As can be seen, after sending a service request, the UE does not check the PDCCH for the first time period, and then checks the PDCCH when or after the first time period has elapsed. This reduces the UE's invalid detection time and saves the UE's power consumption.

[0177] In this embodiment, after the UE sends the first message, it will start detecting the PDCCH when or after the first duration has elapsed, but will not detect the PDCCH during the first duration. The first duration is determined based on the round-trip time between the access network element and the core network element. For example, regardless of the architecture, the first duration takes into account the round-trip time of the transmission of the first message sent by the UE through the satellite and ground network elements during transmission. This is equivalent to the period between the UE receiving the first message from the network and the transmission of the information assuming the network immediately replies, which arrives at the UE. In other words, the UE is unlikely to receive the network's reply information during the first duration, so the UE can choose not to detect the PDCCH during the first duration. However, when or after the first duration has elapsed, the network's reply information may reach the UE, so the UE can start detecting the PDCCH to receive the information. It can be seen that this embodiment does not affect the UE's reception of information from the network and can reduce the time the UE spends ineffectively detecting the PDCCH, thereby saving the UE's power consumption.

[0178] This application provides a second communication method, please refer to the embodiments therein. Figure 10 Here is a flowchart of the method.

[0179] S1001, the UE sends the first message. Correspondingly, the access network element receives the first message.

[0180] In this embodiment, the first message can be an access stratum (AS) message. The UE can send the first message to the access network element, and the access network element can receive the first message. After receiving the first message, the access network element can send corresponding information to the UE. The access network element can also send the information to the UE after interacting with the first core network element. This information may include one or more of the following: contention resolution message (e.g., Msg4 in 4-step random access channel (RACH) or MsgB in 2-step RACH), downlink small packet data, or RRC release message. Specifically, if this embodiment is applied to a 5G system, the first core network element may be, for example, an AMF or a UPF; or, if this embodiment is applied to a 4G system, the first core network element may be, for example, an MME or an S-GW; or, if this embodiment is applied to a 6G system or other communication systems, the first core network element may be a corresponding core network element within that system.

[0181] This application embodiment can be applied to small packet transmission scenarios, for example, S1001 occurs during small packet transmission. The small packet transmission process can end after the UE receives the RRC release message, while S1001 can occur before the UE receives the RRC release message. Alternatively, S1001 can occur after the start of small packet transmission, or S1001 can be considered as the start of the small packet transmission process. For example, SDT or EDT, or other small packet transmission scenarios. Optionally, the first message can be Msg3 in a 4-step RACH or MsgA in a 2-step RACH. For example, Msg3 or MsgA can be used to request the establishment of an RRC connection with the access network element; for instance, Msg3 or MsgA is an RRC connection establishment request message. Optionally, Msg3 or MsgA may include uplink small packet data, or may not include uplink small packet data. If Msg3 or MsgA includes uplink small packet data, the small packet transmission scenario in this application embodiment can be uplink small packet transmission, or uplink small packet transmission + downlink small packet transmission; while if Msg3 or MsgA does not include uplink small packet data, the small packet transmission scenario in this application embodiment can be downlink small packet transmission. In this embodiment, if the small packet transmission scenario is uplink small packet transmission, or uplink small packet transmission + downlink small packet transmission, since the access network element is unsure whether the core network element has downlink small packet data for the UE, the access network element can send information to the UE after interacting with the access network element. Therefore, after the UE sends the first message, the access network element can send information to the UE after interacting with the core network element. Alternatively, if the small packet transmission scenario in this embodiment is downlink small packet transmission, the small packet transmission process can be initiated by the access network element by paging the UE. The access network element clearly has downlink small packet data for the UE, so after receiving the first message, the access network element needs to request downlink small packet data from the core network element. Therefore, after the UE sends the first message, the access network element can send information to the UE after interacting with the core network element.

[0182] Optionally, before S1001, the method may further include S1002 and S1003. In S1002, the UE sends Msg1, and the access network element receives Msg1, which is, for example, a preamble; in S1003, the access network element sends Msg2, and the UE receives Msg2, which is, for example, a RAR. If the UE performs a two-step RACH, then the method may not include S1002 and S1003.

[0183] S1004. When or after the first duration of the first message has been sent, the UE detects the PDCCH.

[0184] Optionally, one method for the UE to detect the PDCCH includes the UE starting a first timer and detecting the PDCCH during the execution of the first timer. The UE can stop detecting the PDCCH when or after the first timer expires. The first timer may be, for example, a contention-resolved timer, or other timers. Optionally, the UE can detect the TC-RNTI scrambled PDCCH during the execution of the contention-resolved timer.

[0185] For example, the start time of the first duration could be the time when the first message is completed, the time when the UE starts sending the first message, or the time when the first offset arrives after the first message is completed. The first offset could be, for example, the UE's processing time.

[0186] Optionally, the UE can determine the first duration using a timer, for example, a second timer. For instance, the UE can start the second timer at the beginning of the first duration, with the second timer's duration being the first duration. The second timer expires when the first duration has elapsed. During the second timer's operation, the UE does not detect the PDCCH, or the UE does not start the first timer. For example, the UE detects the PDCCH when the second timer expires, after it expires, or after it has expired. Alternatively, the UE can start the first timer to detect the PDCCH when the second timer expires, after it expires, or after it has expired. Optionally, when the second timer expires, or after it has expired, the UE can reset the second timer, for example, by resetting its value to the first duration so that the second timer can be used again next time. Alternatively, the UE can determine the first duration using other methods besides the second timer, such as a counter, etc. This embodiment does not limit this approach.

[0187] During the first duration, the UE may not detect the PDCCH, or the UE may not start the first timer. Optionally, the first duration may be determined based on the round-trip time between the access network element and the core network element, where the core network element may include a first core network element; or, the first duration may be determined based on the round-trip time between the access network element and a ground gateway station, where the access network element can communicate with the core network element through the gateway station, which may, for example, refer to... Figure 1C ; optional Figure 1B It may also include gateway stations, such as satellites connecting to the core network elements on the ground through gateway stations.

[0188] For example, regardless of whether it's a regenerator satellite architecture or a wireless backhaul architecture, the first time interval takes into account the round-trip time between the satellite and the ground. This means that while the access network element is determining whether the core network element has downlink small packet data to respond, the UE can delay starting the first timer, for example, delay starting the contention resolution timer. Therefore, when the first timer is not running, the UE does not need to detect the PDCCH. Only after the access network element has relatively certain information from the core network element (e.g., the first core network element) does the UE start the first timer. During the first timer's operation, the UE can detect the TC-RNTI scrambled PDCCH to quickly receive one or more of the following: contention resolution message, potential downlink small packet data, or RRC release message. Therefore, this application embodiment can centrally send the downlink information (e.g., one or more of the following: contention resolution message, downlink small packet data, or RRC release message) that the UE is waiting for to the UE, without affecting the UE's reception of information from the network, and reducing the time the UE spends detecting the PDCCH, thereby saving UE power consumption.

[0189] The duration of the first time interval may vary depending on the network architecture. For example, for a regenerator architecture, the first time interval may include the second and third time intervals; for a wireless backhaul architecture, the first time interval may be a single, continuous duration. For more information on this topic, please refer to [link / reference needed]. Figure 6 The following is a description of the embodiments shown.

[0190] There are different ways for the UE to determine the first duration. As a first possible implementation, the UE can receive a first parameter, and the UE can determine the first duration based on the first parameter. For example, the UE can calculate the duration based on the first parameter, and this duration can be used as the first duration. In this implementation, the access network element only needs to send the parameter to the UE, which is relatively simple for the access network element and can reduce its burden. Alternatively, for a regenerator architecture, the UE determines the first duration based on the first parameter, for example, by determining a second duration based on the first parameter; and for a radio backhaul architecture, the UE can determine the first duration based on the first parameter. See [reference needed] for more information. Figure 6 The following is a description of the embodiments shown.

[0191] As a second optional implementation for the UE to determine the first duration, the UE can receive information about the first duration or the second duration, and thus directly determine the first duration or the second duration based on the received information, without having to perform a calculation process. This implementation reduces the UE's calculation process, simplifies the UE's implementation, and allows the technical solution of this application embodiment to be applied to both high-capacity and low-capacity UEs. For this part, please refer to... Figure 6 The following is a description of the embodiments shown.

[0192] As mentioned above, the first duration or the second duration can be determined based on the round-trip time between the access network element and the core network element, or based on the round-trip time between the access network element and the ground gateway station. The UE can be aware of this; for example, the UE knows the current network architecture and the meaning of the first duration or the second duration. Alternatively, the UE may not be aware of this. For example, the UE may not know the current network architecture, or the UE may know the network architecture but not be aware of the meaning of the first duration or the second duration. In the case where the UE is unaware, the UE can also determine the first duration based on the first parameter, or based on received information (such as information about the first duration or the second duration).

[0193] Optionally, the UE can detect the PDCCH in the manner provided in the embodiments of this application if certain conditions are met, such as detecting the PDCCH when or after the first duration following the completion of the first message transmission; otherwise, the UE may not detect the PDCCH in the manner provided in the embodiments of this application. If the UE does not detect the PDCCH in the manner provided in the embodiments of this application, then, in the case of a regenerator architecture, the UE can delay for a fourth duration after sending the first message before starting to detect the PDCCH. Alternatively, in the case of a radio backhaul architecture, the UE can directly detect the PDCCH after sending the first message without delaying for a fourth duration. In the radio backhaul architecture, the UE can directly detect the PDCCH after sending the first message, for example, the UE can start detecting the PDCCH as soon as the first message is completed; or, the UE can delay for a corresponding second offset after sending the first message before starting to detect the PDCCH, and this second offset may be less than the fourth duration. For this part, such as the content included in the conditions, please refer to [reference needed]. Figure 6 The following is a description of the embodiments shown.

[0194] For example, for a regenerator architecture, if the first message is Msg3, based on network indications (e.g., indicating a regenerator architecture, or indicating corresponding parameters (e.g., K not configured)... mac and / or the fifth parameter; or K is configured. mac =0 and / or the fifth parameter =0), the UE determines that it is a regenerable satellite architecture based on this parameter. If Msg3 is sent through a non-terrestrial network (e.g., through satellite) and carries uplink small packet data, the UE can start the first timer (e.g., contention resolution timer) after Msg3 is sent and add a first duration. Otherwise, if Msg3 is sent through a non-terrestrial network and does not carry uplink small packet data, the UE can start the first timer (e.g., contention resolution timer) after Msg3 is sent and add a fourth duration (e.g., the round-trip delay from the UE to the access network element).

[0195] For example, in a wireless backhaul architecture, if the first message is Msg3, according to network indications (e.g., indicating wireless backhaul architecture, or indicating corresponding parameters, which the UE uses to determine if it is wireless backhaul architecture), if Msg3 carries uplink small packet data, the UE can start the first timer (e.g., contention resolution timer) after Msg3 is sent and add a first duration; otherwise, if Msg3 does not carry uplink small packet data, the UE can start the first timer (e.g., contention resolution timer) when Msg3 is sent or after it is sent.

[0196] For access network elements, after receiving the first message, they can wait for a first duration to send one or more of the following to the UE: a contention resolution message, downlink small packet data, or an RRC release message. For example, the access network element can send one or more of these messages when the first duration of receiving the first message arrives, but not send them within the first duration, to improve the UE's reception success rate. The contention resolution message does not actually require interaction with the core network element, but since the UE also waits for a first duration to receive the contention resolution message, the access network element can also wait for a first duration to maintain consistency with the UE.

[0197] For example, after receiving the first message, the access network element can interact with the first core network element, such as sending information to the first core network element. If the first core network element has downlink small packet data to be sent to the UE, it can send the downlink small packet data to the access network element after receiving the information. In this case, the access network element can send a contention resolution message and the downlink small packet data to the UE. Alternatively, if the first core network element does not have downlink small packet data to be sent to the UE, it can inform the access network element after receiving the information. In this case, the access network element can send a contention resolution message and an RRC release message to the UE. If the access network element has sent downlink small packet data to the UE, after the downlink small packet data transmission is complete, the access network element can send an RRC release message to the UE, or it can send other messages to instruct the UE to enter the RRC connected state.

[0198] Optionally, one or more of the contention resolution message, downlink small packet data, or RRC release message can be scheduled via PDCCH. For example, the UE detects the PDCCH when or after the first duration following the completion of the first message transmission, and can receive one or more of the above according to the scheduling of the PDCCH.

[0199] Please refer to this again. Figure 11 This is a schematic diagram of an embodiment of this application. Figure 11As can be seen, after sending Msg3, the UE does not start the contention resolution timer for the first duration, thus not detecting the PDCCH. The contention resolution timer is then started when the first duration expires, at which point the UE begins detecting the PDCCH, for example, detecting the TC-RNTI scrambled PDCCH. This delays the UE's PDCCH detection time, reducing the invalid detection time after receiving the contention resolution message and saving UE power consumption.

[0200] In this embodiment, after the UE sends the first message, it will start detecting the PDCCH when or after the first duration has elapsed, but will not detect the PDCCH during the first duration. The first duration is determined based on the round-trip time between the access network element and the core network element. For example, regardless of whether it is a regenerable satellite architecture or a radio backhaul architecture, the first duration takes into account the round-trip time between the satellite and the ground. This means that the UE can not detect the PDCCH during the transmission of the information replied by the network, but can detect the PDCCH when the information is about to reach the UE to receive the information. It can be seen that this embodiment does not affect the UE's reception of information from the network, and can reduce the time of the UE's invalid PDCCH detection, thereby saving the UE's power consumption.

[0201] This application provides a third communication method; please refer to [reference needed]. Figure 12 Here is a flowchart of the method.

[0202] S1201, The access network element sends a contention resolution message. Correspondingly, the UE receives the contention resolution message. This contention resolution message is, for example, Msg4 or MsgB during the random access procedure.

[0203] After receiving Msg3 or MsgA, the access network element can send corresponding information to the UE. This information may include one or more of the following: contention resolution message, downlink small packet data, or RRC release message. For the contention resolution message, the access network element can send it directly to the UE without interacting with the core network element. For the downlink small packet data or RRC release message, the access network element can interact with the first core network element before sending it to the UE. If this embodiment is applied to a 5G system, the first core network element may be, for example, an AMF or UPF; or if this embodiment is applied to a 4G system, the first core network element may be, for example, an MME or S-GW; or if this embodiment is applied to a 6G system or other communication systems, the first core network element may be a corresponding core network element within that system.

[0204] Optionally, prior to S1201, the method may further include S1202, S1203, and S1204. In S1202, the UE sends Msg1, which is received by the access network element; Msg1 is, for example, a preamble. In S1203, the access network element sends Msg2, which is received by the UE; Msg2 is, for example, a RAR. In S1204, the UE sends Msg3, which is received by the access network element; Msg3 may request the establishment of an RRC connection with the access network element, for example, an RRC connection establishment request message. If the UE uses a two-step RACH, S1202 and S1203 may be omitted, and Msg3 in S1204 may be replaced with MsgA, which may request the establishment of an RRC connection with the access network element; for example, MsgA is an RRC connection establishment request message.

[0205] This application embodiment can be applied to small packet transmission scenarios, for example, S1201 occurs during small packet transmission. The small packet transmission process can end after the UE receives the RRC release message, while S1201 can occur before the UE receives the RRC release message. Alternatively, S1201 can occur after the start of small packet transmission, or S1201 can be considered as the start of the small packet transmission process. This small packet transmission can be, for example, SDT or EDT, or other small packet transmission scenarios. Optionally, Msg3 or MsgA may include uplink small packet data, or may not include uplink small packet data. If Msg3 or MsgA includes uplink small packet data, the small packet transmission scenario in this application embodiment can be uplink small packet transmission, or uplink small packet transmission + downlink small packet transmission; while if Msg3 or MsgA does not include uplink small packet data, the small packet transmission scenario in this application embodiment can be downlink small packet transmission. In this embodiment, if the small packet transmission scenario is uplink small packet transmission, or uplink small packet transmission + downlink small packet transmission, since the access network element is unsure whether the core network element has downlink small packet data for the UE, the access network element can send downlink small packet data or an RRC release message to the UE after interacting with the access network element. Therefore, after the UE sends Msg3 or MsgA, the access network element can send downlink small packet data or an RRC release message to the UE after interacting with the core network element. Alternatively, if the small packet transmission scenario in this embodiment is downlink small packet transmission, the small packet transmission process can be initiated by the access network element by paging the UE. If the access network element clearly has downlink small packet data for the UE, then after receiving the first message, the access network element needs to request downlink small packet data from the core network element. Therefore, after the UE sends the first message, the access network element can send downlink small packet data or an RRC release message to the UE after interacting with the core network element.

[0206] During the establishment of an RRC connection between the UE and the access network element, the corresponding processing methods may differ depending on the network architecture. For example, in a regenerator architecture, after sending Msg3 or MsgA, the UE can delay for a fourth duration before starting the contention resolution timer, and detect the PDCCH during the contention resolution timer's operation. The UE detects the PDCCH after sending Msg3 or MsgA to receive the contention resolution message in S1201. For example, the UE can start detecting the PDCCH when the fourth duration arrives after Msg3 or MsgA has been sent, but not detect the PDCCH within the fourth duration. The fourth duration can be determined based on the round-trip time delay between the UE and the access network element; optionally, this fourth duration can be the same as the third duration described later, for example, the same parameter. Since the UE needs to wait for a reply from the access network element after sending Msg3 or MsgA (e.g., waiting for a contention resolution message from the access network element), and the contention resolution message is sent by the access network element without interaction between the access network element and the core network element, the UE's waiting time for the contention resolution message does not need to consider the delay between the access network element and the core network element, but only the delay between the UE and the access network element. Therefore, in this embodiment, the UE can wait for a fourth duration after sending Msg3 or MsgA before starting the contention resolution timer. During the timer's operation, the PDCCH is detected. This means the UE can not detect the PDCCH during the transmission of the information replied by the access network element, but can start detecting the PDCCH to receive the information when it is about to arrive at the UE. Optionally, the contention resolution message can be scheduled via PDCCH. For example, the UE can detect the PDCCH after sending Msg3 or MsgA, and receive the contention resolution message according to the PDCCH scheduling. As can be seen, the embodiments of this application do not affect the UE's reception of information from the access network element, and can reduce the time for the UE to detect the PDCCH, thereby saving the UE's power consumption.

[0207] For the wireless backhaul architecture, after sending Msg3 or MsgA, the UE does not need to delay for a fourth duration and can immediately start the contention resolution timer, thereby detecting the PDCCH during the timer's execution. Specifically, the UE can directly detect the PDCCH after sending Msg3 or MsgA, for example, it can start detecting the PDCCH as soon as Msg3 or MsgA is sent; or, the UE can delay for a corresponding second offset after sending Msg3 or MsgA before starting to detect the PDCCH, and this second offset can be less than the fourth duration.

[0208] S1205. When or after the first duration of receiving the contention resolution message has elapsed, or when or after the first duration of the contention resolution timer has stopped, the UE detects the PDCCH.

[0209] Optionally, one method for the UE to detect the PDCCH includes detecting the PDCCH when or after the first duration following the completion of receiving the contention resolution message, or when or after the first duration following the stopping of the contention resolution timer, but not detecting the PDCCH within the first duration. This is equivalent to the UE delaying the start of PDCCH detection after the first duration. This method can reduce the UE's invalid listening while waiting for information transmission between access network elements and core network elements, thus helping the UE save energy.

[0210] Optionally, one method for the UE to detect the PDCCH includes the UE starting a third timer and detecting the PDCCH during the operation of the third timer. The UE can stop detecting the PDCCH when or after the third timer expires.

[0211] For example, the start time of the first duration could be the time when the contention resolution message is received, the time when the UE starts receiving the contention resolution message, or the time when the first offset arrives after the contention resolution message is received. This first offset could be, for example, the UE's processing time, or the time when or after the contention resolution timer stops. When the UE receives its own contention resolution message, it can stop the contention resolution timer.

[0212] Optionally, the UE can determine the first duration using a timer, for example, a second timer. For instance, the UE can start the second timer at the beginning of the first duration, with the second timer's duration being the first duration. The second timer expires when the first duration has elapsed. During the second timer's operation, the UE does not detect the PDCCH. For example, the UE detects the PDCCH when, after, or when the second timer expires. Alternatively, the UE can start a third timer when or after the second timer expires to detect the PDCCH. Optionally, when the second timer expires, the UE can reset the second timer, for example, by resetting its value to the first duration, so that the second timer can be used again next time. Alternatively, the UE can determine the first duration using other methods besides the second timer, such as a counter, which is not limited in this embodiment.

[0213] During the first duration, the UE may not detect the PDCCH, or the UE may not start the third timer. For example, the UE may not detect the C-RNTI scrambled PDCCH during the first duration. Optionally, the first duration may be determined based on the round-trip delay between the access network element and the core network element, where the core network element may include a first core network element; or, the first duration may be determined based on the round-trip delay between the access network element and a ground gateway station, where the access network element can communicate with the core network element through the gateway station, which may, for example, refer to... Figure 1C ; optional Figure 1BIt may also include gateway stations, such as satellites connecting to the core network elements on the ground through gateway stations.

[0214] For example, regardless of whether it's a regenerator satellite architecture or a wireless backhaul architecture, the first time interval takes into account the round-trip delay between the satellite and the ground. This means that while the access network element is determining whether the core network element has downlink small packet data to reply, the UE can delay starting the third timer, thus not detecting the PDCCH when the first timer is not running. Only after the access network element has relatively certain information from the core network element (e.g., the first core network element) does the UE start the third timer. During the third timer's operation, the UE can detect the PDCCH to quickly detect potential downlink small packet data or RRC release messages. Therefore, the embodiments of this application do not affect the UE's reception of information from the network and reduce the time the UE spends detecting the PDCCH, thereby saving UE power consumption.

[0215] The duration of the first duration may vary depending on the network architecture. For example, for a regenerator architecture, the first duration may include a second duration; details regarding the second duration can be found in [reference needed]. Figure 6 The illustrated embodiment is described, wherein... Figure 6 The difference between the illustrated embodiments and the actual embodiments is that the first duration in this application may include a second duration but not a third duration. For example, in a wireless backhaul architecture, the first duration may be a single, continuous period, as can be found in [reference needed]. Figure 6 The following is a description of the embodiments shown.

[0216] There are different ways for the UE to determine the first duration. As a first possible implementation, the UE can receive a first parameter, and the UE can determine the first duration based on the first parameter. For example, the UE can calculate the duration based on the first parameter, and this duration can be used as the first duration. In this implementation, the access network element only needs to send the parameter to the UE, which is relatively simple for the access network element and can reduce its burden. Alternatively, for a regenerator architecture, the UE determines the first duration based on the first parameter, for example, by determining a second duration based on the first parameter; and for a radio backhaul architecture, the UE can determine the first duration based on the first parameter. See [reference needed] for more information. Figure 6 The following is a description of the embodiments shown.

[0217] As a second optional implementation for the UE to determine the first duration, the UE can receive information about the first duration or the second duration, and thus directly determine the first duration or the second duration based on the received information, without having to perform a calculation process. For more information on this, please refer to [link / reference needed]. Figure 6The embodiments shown are described below. This implementation reduces the computational process of the UE, simplifies the implementation of the UE, and allows the technical solutions of this application to be applied to both high-capacity and low-capacity UEs.

[0218] As mentioned above, the first duration or the second duration can be determined based on the round-trip time between the access network element and the core network element, or based on the round-trip time between the access network element and the ground gateway station. The UE can be aware of this; for example, the UE knows the current network architecture and the meaning of the first duration or the second duration. Alternatively, the UE may not be aware of this. For example, the UE may not know the current network architecture, or the UE may know the network architecture but not be aware of the meaning of the first duration or the second duration. In the case where the UE is unaware, the UE can also determine the first duration based on the first parameter, or based on received information (such as information about the first duration or the second duration).

[0219] Optionally, the UE can detect the PDCCH in the manner provided in the embodiments of this application if certain conditions are met, such as detecting the PDCCH when or after the first duration of the contention resolution message has been received; otherwise, the UE may not detect the PDCCH in the manner provided in the embodiments of this application. If the UE does not detect the PDCCH in the manner provided in the embodiments of this application, then, in the case of a regenerator architecture, the UE can delay for four durations after receiving the contention resolution message before starting to detect the PDCCH. Alternatively, in the case of a radio backhaul architecture, the UE can detect the PDCCH without delaying for four durations after receiving the contention resolution message. In the radio backhaul architecture, the UE can directly detect the PDCCH after receiving the contention resolution message, for example, the UE can start detecting the PDCCH as soon as the contention resolution message is received; or, the UE can delay by a corresponding offset after receiving the contention resolution message before starting to detect the PDCCH, and this offset may be less than the fourth duration. For this part, such as the content included in the conditions, please refer to [reference needed]. Figure 6 The following is a description of the embodiments shown.

[0220] For example, for a regenerating star architecture, this might be based on network indications (e.g., indicating a regenerating star architecture, or indicating corresponding parameters (e.g., K not configured)). mac and / or the fifth parameter; or K is configured. macWhen the contention resolution message is received (or the fifth parameter is 0), the UE stops the contention resolution timer. If the UE is transmitting small packets, the UE can start a second timer. During the second timer's operation, the UE does not detect the C-RNTI scrambled PDCCH. When the second timer's duration expires or after it expires, the UE can detect the C-RNTI scrambled PDCCH; otherwise, if the UE is not transmitting small packets, the UE can detect the C-RNTI scrambled PDCCH after receiving the contention resolution message.

[0221] For example, in a radio backhaul architecture, based on network indications (such as indicating a radio backhaul architecture or indicating corresponding parameters, which the UE uses to determine if it is a radio backhaul architecture), the UE can stop the contention resolution timer after receiving the contention resolution message. If the UE is performing small packet transmission, the UE can start a second timer. During the second timer's operation, the UE does not detect the C-RNTI-scrambled PDCCH. When the second timer's duration expires or after it expires, the UE can detect the C-RNTI-scrambled PDCCH; otherwise, if the UE is not performing small packet transmission, the UE can detect the C-RNTI-scrambled PDCCH after receiving the contention resolution message.

[0222] For access network elements, after sending a contention resolution message, they can wait for a first duration before sending downlink small packet data or an RRC release message to the UE. For example, the access network element can send downlink small packet data or an RRC release message when or after the first duration of sending the contention resolution message has elapsed, but not during the first duration. This allows more time for the core network element to send the corresponding information to the UE, improving the UE's reception efficiency. For the UE, since the access network element is waiting for information from the core network element, the UE does not need to detect the PDCCH, thus saving energy.

[0223] For example, after receiving Msg3 or MsgA, the access network element can interact with the first core network element, such as sending information to the first core network element. If the first core network element has downlink small packet data to be sent to the UE, it can send the downlink small packet data to the access network element after receiving the information. In this case, the access network element can send the downlink small packet data to the UE. Alternatively, if the first core network element does not have downlink small packet data to be sent to the UE, it can inform the access network element after receiving the information. In this case, the access network element can send an RRC release message to the UE. If the access network element has sent downlink small packet data to the UE, after the downlink small packet data transmission is complete, the access network element can send an RRC release message to the UE, or it can send other messages to instruct the UE to enter the RRC connected state.

[0224] Optionally, the downlink small packet data or the RRC release message can be received by the PDCCH. For example, the UE detects the PDCCH when or after the first duration of receiving the contention resolution message has elapsed, and can receive the downlink small packet data or the RRC release message according to the scheduling of the PDCCH.

[0225] Please refer to this again. Figure 13 This is a schematic diagram of an embodiment of this application. According to... Figure 13 As can be seen, after receiving the contention resolution message, the UE will not detect the PDCCH for the first time period, and will then detect the PDCCH when the first time period expires. This reduces the UE's invalid detection time and saves the UE's power consumption.

[0226] In this embodiment, after receiving the contention resolution message, the UE will begin detecting the PDCCH when or after the first duration has elapsed, but will not detect the PDCCH during the first duration. The first duration is determined based on the round-trip time between the access network element and the core network element. For example, regardless of whether it is a regenerable satellite architecture or a radio backhaul architecture, the first duration takes into account the round-trip time between the satellite and the ground. This means that the UE can not detect the PDCCH during the transmission of information replied by the network, but can detect the PDCCH when the information is about to arrive at the UE to receive the information. Therefore, this embodiment does not affect the UE's reception of information from the network and reduces the time the UE spends ineffectively detecting the PDCCH, thereby saving the UE's power consumption.

[0227] Figure 14 A schematic diagram of a communication device according to an embodiment of this application is provided. The communication device 1400 may be... Figure 6 , Figure 10 or Figure 12The UE or its circuitry, as shown in any of the accompanying drawings, is used to implement the method corresponding to the UE in the above method embodiments. Alternatively, the communication device 1400 may be... Figure 6 , Figure 10 or Figure 12 The access network element or its circuit system, as shown in any of the accompanying drawings, is used to implement the method corresponding to the access network element in the above method embodiments. Alternatively, the communication device 1400 may be... Figure 6 , Figure 10 or Figure 12 The first core network element or its circuit system, as shown in any of the accompanying drawings, is used to implement the method corresponding to the first core network element in the above method embodiments. For example, one such circuit system is a chip system.

[0228] The communication device 1400 includes at least one processor 1401. The processor 1401 can be used for internal processing within the device to implement certain control processing functions. Optionally, the processor 1401 includes instructions. Optionally, the processor 1401 can store data. Optionally, different processors can be independent devices, located in different physical locations, or located on different integrated circuits. Optionally, different processors can be integrated into one or more processors, for example, integrated on one or more integrated circuits.

[0229] Optionally, the communication device 1400 includes one or more memories 1403 for storing instructions. Optionally, the memories 1403 may also store data. The processor and the memories may be separate or integrated together.

[0230] Optionally, the communication device 1400 includes a communication line 1402 and at least one communication interface 1404. Since the memory 1403, communication line 1402, and communication interface 1404 are all optional, therefore... Figure 14 All are represented by dashed lines.

[0231] Optionally, the communication device 1400 may further include a transceiver and / or an antenna. The transceiver can be used to send information to or receive information from other devices. The transceiver may be referred to as a transceiver unit, transceiver circuit, input / output interface, etc., and is used to realize the transmission and reception functions of the communication device 1400 via the antenna. Optionally, the transceiver includes a transmitter and a receiver. For example, the transmitter can be used to generate a radio frequency (RF) signal from a baseband signal, and the receiver can be used to convert the RF signal back into a baseband signal.

[0232] Processor 1401 may include a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of programs according to the present application.

[0233] Communication line 1402 may include a path for transmitting information between the aforementioned components.

[0234] Communication interface 1404 uses any transceiver-like device for communicating with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area network (WLAN), wired access network, etc.

[0235] Memory 1403 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. Memory 1403 may exist independently and be connected to processor 1401 via communication line 1402. Alternatively, memory 1403 may be integrated with processor 1401.

[0236] The memory 1403 stores computer execution instructions for implementing the scheme of this application, and its execution is controlled by the processor 1401. The processor 1401 executes the computer execution instructions stored in the memory 1403, thereby realizing... Figure 6 , Figure 10 or Figure 12 The steps performed by the UE, access network element, or first core network element as shown in any of the accompanying drawings.

[0237] Optionally, the computer execution instructions in the embodiments of this application may also be referred to as application code, and the embodiments of this application do not specifically limit this.

[0238] In a specific implementation, as one embodiment, the processor 1401 may include one or more CPUs, for example... Figure 14 CPU0 and CPU1 in the CPU.

[0239] In a specific implementation, as one example, the communication device 1400 may include multiple processors, such as... Figure 14 Processors 1401 and 1405 are mentioned. Each of these processors can be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor here can refer to one or more devices, circuits, and / or processing cores used to process data (such as computer program instructions).

[0240] when Figure 14 When the device shown is a chip, such as a UE chip, an access network element chip, or a first core network element chip, the chip includes a processor 1401 (and may also include a processor 1405), a communication line 1402, and a communication interface 1404. Optionally, it may include a memory 1403. Specifically, the communication interface 1404 may be an input interface, pins, or circuits, etc. The memory 1403 may be a register, cache, etc. The processor 1401 and processor 1405 may be a general-purpose CPU, microprocessor, ASIC, or one or more integrated circuits for controlling the execution of a program that controls the communication method of any of the above embodiments.

[0241] This application embodiment can divide the device into functional modules according to the above method example. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing module. The integrated modules can be implemented in hardware or as software functional modules. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods. For example, when dividing the device into functional modules according to each function, Figure 15 This is a schematic diagram of an apparatus. The apparatus 1500 may be a UE, an access network element, or a first core network element involved in the above-described method embodiments, or it may be a chip in the UE, a chip in the access network element, or a chip in the first core network element. The apparatus 1500 includes a processing unit 1502 and a transceiver unit 1501.

[0242] It should be understood that the device 1500 can be used to implement the steps performed by the UE, access network element, or first core network element in the communication method of the embodiments of this application, and the relevant features can be referred to above. Figure 6 , Figure 10 or Figure 12 The embodiments shown in any of the accompanying drawings will not be described in detail here.

[0243] Optional, Figure 15 The functions / implementation process of the transceiver unit 1501 and the processing unit 1502 can be obtained through Figure 14 The processor 1401 in the memory calls computer execution instructions stored in memory 1403 to implement the function. Alternatively, Figure 15 The function / implementation process of the processing unit 1502 can be achieved through... Figure 14 The processor 1401 in the memory calls computer execution instructions stored in memory 1403 to implement this. Figure 15 The function / implementation process of the transceiver unit 1501 can be obtained through Figure 14 It is implemented using the communication interface 1404.

[0244] Optionally, when the device 1500 is a chip or circuit, the function / implementation process of the transceiver unit 1501 can also be implemented through pins or circuits, etc. Optionally, the transceiver unit 1501 may include a transmitting unit and / or a receiving unit, whereby the transmitting unit implements the transmitting function and the receiving unit implements the receiving function; or, the transceiver unit 1501 may be an integral module capable of implementing both transmitting and / or receiving functions. Optionally, the transceiver unit 1501 can be implemented using a transceiver.

[0245] This application also provides a computer-readable storage medium storing a computer program or instructions. When the computer program or instructions are executed, they implement the methods performed by the UE, access network element, or first core network element in the aforementioned method embodiments. Thus, the functions described in the above embodiments can be implemented as software functional units and sold or used as independent products. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to it, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0246] This application also provides a computer program product, which includes: computer program code, which, when run on a computer, causes the computer to perform the method executed by the UE, access network element, or first core network element in any of the foregoing method embodiments.

[0247] This application also provides a processing apparatus, including a processor and an interface; the processor is used to execute the methods performed by the UE, access network element, or first core network element involved in any of the above method embodiments.

[0248] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0249] The various illustrative logic units and circuits described in the embodiments of this application can be implemented or operate the described functions using a general-purpose processor, digital signal processor (DSP), ASIC, field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. The general-purpose processor can be a microprocessor; alternatively, it can be any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented using a combination of computing devices, such as a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors combined with a digital signal processor core, or any other similar configuration.

[0250] The steps of the methods or algorithms described in the embodiments of this application can be directly embedded in hardware, software units executed by a processor, or a combination of both. The software units can be stored in RAM, flash memory, ROM, erasable programmable read-only memory (EPROM), EEPROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium in the art. Exemplarily, the storage medium can be connected to the processor so that the processor can read information from the storage medium and write information to the storage medium. Optionally, the storage medium can also be integrated into the processor. The processor and storage medium can be disposed in an ASIC, which can be disposed in the terminal device. Optionally, the processor and storage medium can also be disposed in different components of the terminal device.

[0251] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

[0252] The contents of the various embodiments of this application can be referenced to each other. Unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0253] It is understood that in the embodiments of this application, the UE and / or access network element and / or first core network element may execute some or all of the steps in the embodiments of this application. These steps or operations are merely examples. In the embodiments of this application, other operations or variations of various operations may also be performed. Furthermore, the steps may be performed in different orders as presented in the embodiments of this application, and it is not necessarily necessary to perform all the operations in the embodiments of this application.

Claims

1. A communication method, characterized in that, The method includes: Send the first message; When or after the first duration of the first message has been sent, the PDCCH is detected. However, the PDCCH is not detected within the first duration. The first duration is determined based on the round-trip time between the access network element of the serving terminal device and the core network element serving the terminal device. The communication link between the access network element and the core network element includes a satellite-to-ground link.

2. The method according to claim 1, characterized in that, The access network element is located on the satellite, or the access network element is the satellite, wherein... The first duration includes a second duration and a third duration. The second duration is determined based on the round-trip time between the access network element and the core network element, and the third duration is determined based on the round-trip time between the terminal device and the access network element.

3. The method according to claim 2, characterized in that, The method further includes: Receive a first parameter, which is used to determine the first duration or the second duration; or, Receive information for the second duration.

4. The method according to claim 1, characterized in that, The access network element and the core network element are located on the ground, and the access network element and the core network element communicate via the satellite. The first duration is determined based on the round-trip time between the access network element serving the terminal device and the core network element serving the terminal device, and includes: The first duration is determined based on the round-trip time between the access network element and the satellite, and the round-trip time between the satellite and the core network element.

5. The method according to claim 4, characterized in that, The method further includes: Receive a first parameter, which is used to determine the first duration; or, Receive information for the first duration.

6. The method according to claim 3 or 5, characterized in that, The first parameter is included in the system information.

7. The method according to any one of claims 1 to 6, characterized in that, The first message is used to request registration with the first core network element; or, The first message is used to request services from the first core network element; or, The first message is used to send the authentication response of the terminal device to the first core network element; or, The first message is used to send a NAS security command response to the first core network element; or, The first message is used to request the establishment of an RRC connection with the access network element during small packet transmission.

8. The method according to claim 7, characterized in that, The first message is the RRC connection establishment request message, which detects the PDCCH and includes: Start a first timer and detect the PDCCH during the operation of the first timer.

9. The method according to claim 8, characterized in that, The method further includes: In response to the PDCCH, a contention resolution message is received.

10. The method according to any one of claims 7 to 9, characterized in that, The first message is the RRC connection establishment request message, which also includes uplink small packet data.

11. A communication method, characterized in that, The method includes: During small packet transmission, a contention resolution message is received; When or after the first duration of receiving the contention resolution message has elapsed, the PDCCH is detected. However, the PDCCH is not detected within the first duration. The first duration is determined based on the round-trip time between the access network element of the serving terminal device and the core network element serving the terminal device. The communication link between the access network element and the core network element includes a satellite-to-ground link.

12. The method according to claim 11, characterized in that, The access network element is located on the satellite, or the access network element is the satellite, wherein... The first duration includes a second duration and a third duration. The second duration is determined based on the round-trip time between the access network element and the core network element, and the third duration is determined based on the round-trip time between the terminal device and the access network element.

13. The method according to claim 12, characterized in that, The method further includes: Receive a first parameter, which is used to determine the first duration or the second duration; or, Receive information for the second duration.

14. The method according to claim 11, characterized in that, The access network element and the core network element are located on the ground, and the access network element and the core network element communicate via the satellite. The first duration is determined based on the round-trip time between the access network element serving the terminal device and the core network element serving the terminal device, and includes: The first duration is determined based on the round-trip time between the access network element and the satellite, and the round-trip time between the satellite and the core network element.

15. The method according to claim 14, characterized in that, The method further includes: Receive a first parameter, which is used to determine the first duration; or, Receive information for the first duration.

16. The method according to claim 13 or 15, characterized in that, The first parameter is included in the system information.

17. A communication method, characterized in that, The method includes: Send first information, which includes a first parameter, information of a first duration, or information of a second duration. The first parameter is used to determine the first duration or the second duration. The first duration includes the second duration, which is determined based on the round-trip time between the access network element and the core network element. Alternatively, the first duration is determined based on the round-trip time between the access network element and the satellite, and the round-trip time between the satellite and the core network element.

18. The method according to claim 17, characterized in that, The first piece of information is included in the system information.

19. A communication device, characterized in that, The communication device includes a module for performing the method as described in any one of claims 1 to 10, or a module for performing the method as described in any one of claims 11 to 16, or a module for performing the method as described in any one of claims 17 to 18.

20. A communication device, characterized in that, The communication device includes a processor configured to perform the method as described in any one of claims 1 to 10, or the method as described in any one of claims 11 to 16, or the method as described in any one of claims 17 to 18.

21. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store a computer program that, when run on a computer, causes the method as described in any one of claims 1 to 10 to be performed, or causes the method as described in any one of claims 11 to 16 to be performed, or causes the method as described in any one of claims 17 to 18 to be performed.

22. A computer program product, characterized in that, The computer program product includes a computer program that, when run on a computer, causes the computer to perform the method as described in any one of claims 1 to 10, or causes the computer to perform the method as described in any one of claims 11 to 16, or causes the computer to perform the method as described in any one of claims 17 to 18.

Images