Communication method, and apparatus

Abstract

A communication method and an apparatus, relating to the technical field of wireless communications. The method comprises: a terminal device receives first instruction information, the first instruction information being used for instructing the terminal device to change from a RRC connection state to a first state; and the terminal enters the first state on the basis of the first instruction information, and in the first state, releases a RRC connection between the terminal device and a network device, so as to enable measurement on a reference signal aperiodically sent.

Description

A communication method and apparatus

[0001] Cross-reference to Related Applications

[0002] This application claims priority to the Chinese Patent Application No. 202411247589.5, filed on September 5, 2024, and entitled “A communication method and apparatus”, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of wireless communication, and in particular to a communication method and apparatus. BACKGROUND

[0004] In a long term evolution (LTE) system, a radio resource control (RRC) state of a terminal device includes an RRC connected state and an RRC idle state. In the RRC connected state, there is a signaling connection between the terminal device and a base station, and the terminal device and the base station can perform data transmission, or there can be no data transmission between the terminal device and the base station but only RRC signaling transmission. In the RRC idle state, there is no signaling connection between the terminal device and the base station, and there is neither data transmission nor RRC signaling transmission between the terminal device and the base station. When the terminal device is in the RRC idle state, a core network can page the terminal device through one or more base stations in an area corresponding to a tracking area identity (TAI) list. When the terminal device moves out of the area corresponding to the TAI list, a core network registration procedure can be initiated, a non-access stratum (NAS) registration update is performed, the core network registers a location of the terminal device and updates a terminal device registration area of the terminal device, i.e., reassigns the TAI list containing a tracking area (TA) to which a cell currently located by the terminal device belongs to the terminal device.

[0005] In a 5th generation (5G) system, an RRC inactive state is introduced on the basis of the RRC connected state and the RRC idle state. In the RRC connected state, an RRC connection is established between the terminal device and the base station; in the RRC idle state, there is no RRC connection between the terminal device and the base station, and the base station does not need to maintain context information of the terminal device; and in the RRC inactive state, the terminal device suspends data processing, but the base station still maintains context information of the terminal device, which can enable the terminal device to quickly recover to the RRC connected state.

[0006] The terminal device in the RRC inactive state can maintain a power consumption level close to that in the RRC idle state because the data processing is suspended. Meanwhile, the base station still maintains the context information of the terminal device in the RRC inactive state, so the terminal device is still in a connection management connected (CM-connected) state, that is, the terminal device still has a signaling connection with an access and mobility management function (AMF), and therefore, when the terminal device needs to be migrated from the RRC inactive state to the RRC connected state because of data transmission requirements, the terminal device does not need to perform procedures such as bearer establishment and authentication, compared with migration from the RRC idle state to the RRC connected state, and therefore, the service of the terminal device can be restored more quickly.

[0007] To obtain energy saving benefits of the terminal device, the terminal device can use a small data transmission (SDT) technology in the RRC inactive state to implement small packet transmission of the terminal device in the RRC inactive state, so as to reduce signaling transmission and increase the time during which the terminal device is in the non-RRC connected state, thereby obtaining higher energy saving effects.

[0008] In terms of data transmission, in the RRC connected state, the terminal device can perform channel measurement based on periodic reference signals, and select appropriate bandwidth resources for data transmission with the network side, thereby improving data transmission efficiency; in the RRC inactive state, the terminal device can perform small packet transmission with the network side, but because channel measurement is not performed based on reference signals, appropriate bandwidth resources cannot be selected, and therefore, compared with the RRC connected state, the data transmission efficiency is lower. In terms of energy saving, in the RRC connected state, the terminal device needs to perform channel measurement on periodic reference signals, and therefore, the power consumption is high and the energy saving effect is poor; in the RRC non-connected state, the terminal device does not need to perform channel measurement on reference signals, and therefore, compared with the RRC connected state, the power consumption is low and the energy saving effect is good. It can be seen that the RRC connected state and the RRC inactive state cannot balance data transmission efficiency and energy saving.

[0009] Therefore, how to ensure data transmission efficiency while saving energy is a problem that needs to be solved at present. SUMMARY

[0010] Embodiments of the present application provide a communication method and device to ensure data transmission efficiency while saving energy.

[0011] Some embodiments of the present application can be applied to a terminal-side device, which can be a terminal device, or a module (such as a chip) in a terminal device, or software (such as a control subsystem) containing terminal device functions. Some other embodiments of the present application can be applied to a network-side device, which can be a network device, such as a base station or a radio access network device, or a module (such as a chip) in a network device, or software (such as a control subsystem) containing network device functions.

[0012] In a first aspect, a communication method is provided, which can be applied to a terminal device. The method comprises: receiving first indication information, the first indication information being used to indicate that the terminal device changes from an RRC connected state to a first state; and entering the first state according to the first indication information, in the first state, the RRC connection of the terminal device with a network device is released, and the terminal device starts measurement on aperiodically transmitted reference signals.

[0013] In the above implementation, the first state is introduced, and the terminal device does not need to maintain an RRC connection in the first state and can start measurement on aperiodically transmitted reference signals. On the one hand, compared with measurement on periodic reference signals in the RRC connected state, the power consumption of the terminal device can be reduced to achieve energy saving. On the other hand, since measurement is performed on aperiodically transmitted reference signals, resource selection can be performed based on the measurement results for subsequent data transmission. Compared with the case where the terminal device does not perform measurement on reference signals when performing small packet transmission in the RRC inactive state, the above implementation can improve transmission efficiency when data transmission is performed.

[0014] In a possible implementation, the first indication information is carried in L3 signaling.

[0015] In a possible implementation, before the receiving of the first indication information, the method further comprises: sending service information, the service information being used to make a decision on RRC state change.

[0016] In a possible implementation, the service information comprises one or more of the following: service data volume, service data volume change trend, service duration, and service type.

[0017] In a possible implementation, before the receiving of the first indication information, the method further comprises: sending state change tendency information, the state change tendency information indicating the first state.

[0018] In a possible implementation, the state change tendency information comprises first duration information, the first duration information being used to indicate a duration of the first state.

[0019] In a possible implementation, the sending of the state change tendency information comprises: sending the first information when one or more of the following conditions are met: the service data volume is less than or equal to a data volume threshold; the change trend of the service data volume is a downward trend; and the duration of the service is less than or equal to a duration threshold.

[0020] In a possible implementation, in the first state, the terminal device further comprises: receiving a reference signal of at least one cell according to a first period; wherein the length of the first period is determined according to the length of a second period and a measurement relaxation factor, wherein the second period is a measurement period of the terminal device in the RRC connected state or the RRC inactive state; and performing cell reselection according to the reference signal of the at least one cell.

[0021] By using the above implementation, the power consumption of the terminal device can be saved.

[0022] In a possible implementation, the length of the first period is greater than the length of the second period.

[0023] In a possible implementation, the measurement relaxation factor is an integer greater than 1, and the length of the second period is an integer multiple of the length of the first period.

[0024] In a possible implementation, in the first state, the terminal device further comprises: receiving second indication information, wherein the second indication information is used to indicate that the terminal device changes from the first state to the RRC connected state; and entering the RRC connected state according to the second indication information, wherein in the RRC connected state, the terminal device resumes the RRC connection between the terminal device and the network device, and stops measuring the aperiodically transmitted reference signal.

[0025] Optionally, the second indication information is carried in L3 signaling.

[0026] In a possible implementation, before the receiving of the second indication information, the terminal device further comprises: sending service information and / or state change tendency information, wherein the service information is used to make a decision on RRC state change, and the state change tendency information indicates the RRC connected state.

[0027] In a possible implementation, in the first state, the terminal device further comprises: receiving third indication information, wherein the third indication information is used to indicate that the terminal device changes from the first state to the RRC idle state; and entering the RRC idle state according to the third indication information, wherein in the RRC idle state, the RRC connection between the terminal device and the network device is released.

[0028] Optionally, the third indication information is carried in L1 signaling, L2 signaling, or L3 signaling.

[0029] In a possible implementation, in the first state, the terminal device further includes: receiving fourth indication information, the fourth indication information being used to indicate that the terminal device changes from the first state to an RRC inactive state; and entering the RRC inactive state according to the fourth indication information, and the terminal device stops measurement on the aperiodically transmitted reference signal in the RRC inactive state.

[0030] Optionally, the fourth indication information is carried in L1 signaling, L2 signaling, or L3 signaling.

[0031] In a possible implementation, in the RRC inactive state, the terminal device further includes: receiving fifth indication information, the fifth indication information being used to indicate that the terminal device changes from the RRC inactive state to the first state; and entering the first state according to the fifth indication information, and the terminal device resumes measurement on the aperiodically transmitted reference signal in the first state.

[0032] In a possible implementation, the receiving of the fifth indication information includes: receiving a first message and first reference signal sent along with the first message, the fifth indication information being included in the first message; performing time-frequency synchronization according to the first reference signal; initiating a network access procedure according to the first message, and changing from the RRC inactive state to the first state.

[0033] In a possible implementation, the method further includes: performing channel measurement according to the first reference signal to obtain a channel measurement result; and sending the channel measurement result based on an uplink message in the network access procedure.

[0034] In a possible implementation, the initiating of the network access procedure according to the first message includes: sending a second reference signal according to the first message, the second reference signal being used to request access to the network and for channel measurement.

[0035] In a possible implementation, the receiving of the fifth indication information includes: determining to change from the RRC inactive state to the first state; sending a second message, the second message being used to request to change from the RRC inactive state to the first state; and receiving third message corresponding to the second message, the fifth indication information being included in the third message.

[0036] In a possible implementation, in the RRC inactive state, the terminal device further includes: receiving sixth indication information, the sixth indication information being used to indicate that the terminal device receives data on a first time-frequency resource; the first time-frequency resource is a resource configured for terminal devices in the first state to use for data transmission; and the terminal device enters the first state according to the sixth indication information, and in the first state, the terminal device resumes measurement of the aperiodically transmitted reference signal and receives data on the first time-frequency resource.

[0037] In a possible implementation, the aperiodically transmitted reference signal is a reference signal transmitted along with a channel.

[0038] In a possible implementation, in the first state, the terminal device further includes: receiving downlink data and a reference signal transmitted along with the downlink data; measuring the reference signal to obtain a measurement result; and transmitting the measurement result.

[0039] In the above implementation, in the first state, the terminal device can perform channel measurement based on the reference signal transmitted along with a channel and report the channel measurement result, so as to select a resource for subsequent data transmission, thereby ensuring the efficiency of data transmission, and compared with the RRC connected state, the terminal device does not need to perform measurement on a periodic reference signal, thereby saving power consumption of the terminal device.

[0040] In a second aspect, a communication method is provided, which can be applied to a terminal device. The method includes: in a first state, receiving, by the terminal device, second indication information, the second indication information being used to indicate that the terminal device changes from the first state to an RRC connected state; and entering, by the terminal device, the RRC connected state according to the second indication information, in the RRC connected state, the terminal device resumes RRC connection between the terminal device and a network device, and stops measurement of a non-periodically transmitted reference signal.

[0041] In a possible implementation, before the receiving of the second indication information, the method further includes: transmitting service information and / or state change tendency information, the service information being used to make a decision on RRC state change, and the state change tendency information indicating the RRC connected state.

[0042] In a third aspect, a communication method is provided, which can be applied to a terminal device. The method includes: in an RRC inactive state, receiving, by the terminal device, fifth indication information, the fifth indication information being used to indicate that the terminal device changes from the RRC inactive state to a first state; and entering, by the terminal device, the first state according to the fifth indication information, in the first state, the terminal device resumes measurement of a non-periodically transmitted reference signal.

[0043] In a possible implementation, the receiving the fifth indication information comprises: receiving a first message and a first reference signal sent along with the first message, the fifth indication information being included in the first message; performing time-frequency synchronization according to the first reference signal; initiating a network access procedure according to the first message, and changing from an RRC inactive state to the first state.

[0044] In a possible implementation, the method further comprises: performing channel measurement according to the first reference signal to obtain a channel measurement result; and sending the channel measurement result based on an uplink message in the network access procedure.

[0045] In a possible implementation, the initiating the network access procedure according to the first message comprises: sending a second reference signal according to the first message, the second reference signal being used for requesting network access and for channel measurement.

[0046] In a possible implementation, the receiving the fifth indication information comprises: determining to change from an RRC inactive state to the first state; sending a second message, the second message being used for requesting to change from the RRC inactive state to the first state; and receiving a third message corresponding to the second message, the fifth indication information being included in the third message.

[0047] In a fourth aspect, a communication method is provided, which can be applied to a terminal device. The method comprises: receiving, by the terminal device in an RRC inactive state, sixth indication information, the sixth indication information being used to indicate that the terminal device receives data on first time-frequency resources; wherein the first time-frequency resources are resources configured for terminal devices in the first state to perform data transmission; and entering, by the terminal device, the first state according to the sixth indication information, the terminal device in the first state resuming measurement on aperiodically sent reference signals and receiving data on the first time-frequency resources.

[0048] In a possible implementation, if a current RRC state of the terminal device does not match the first state corresponding to the first time-frequency resources, the terminal device changes from the current RRC state to the first state.

[0049] In a fifth aspect, a communication method is provided, which can be applied to a network device. The method comprises: sending first indication information, the first indication information being used to indicate that a terminal device changes from an RRC connected state to a first state, the terminal device in the first state releasing an RRC connection with the network device and starting measurement on aperiodically sent reference signals; and releasing, by the network device, an RRC connection between the network device and the terminal device.

[0050] In a possible implementation, before the first indication information is sent, the method further includes: receiving service information corresponding to the terminal device; and determining to change the terminal device from the RRC connected state to the first state according to the service information.

[0051] In a possible implementation, the service information includes one or more of the following: a service data volume, a change trend of the service data volume, a service duration, and a service type.

[0052] In a possible implementation, before the first indication information is sent, the method further includes: receiving state change tendency information of the terminal device, the state change tendency information indicating the first state; and determining to change the terminal device from the RRC connected state to the first state according to the state change tendency information.

[0053] In a possible implementation, the state change tendency information includes first duration information, the first duration information being used to indicate a duration of the first state; and the method further includes: determining a length of time that the terminal device stays in the first state according to the first duration information.

[0054] In a possible implementation, the method further includes: stopping sending a periodic reference signal to the terminal device; and / or, stopping measuring the periodic reference signal sent by the terminal device.

[0055] In a possible implementation, after the first indication information is sent, the method further includes: sending second indication information, the second indication information being used to indicate that the terminal device changes from the first state to the RRC connected state; and resuming the RRC connection with the terminal device.

[0056] In a possible implementation, the method further includes: receiving service information corresponding to the terminal device; and determining to change the terminal device from the first state to the RRC connected state according to the service information.

[0057] In a possible implementation, the method further includes: receiving state change tendency information of the terminal device, the state change tendency information indicating the RRC connected state; and determining to change the terminal device from the first state to the RRC connected state according to the state change tendency information.

[0058] In a possible implementation, the method further includes: resuming sending a periodic reference signal to the terminal device; and / or, resuming measuring the periodic reference signal sent by the terminal device.

[0059] In a possible implementation manner, after the first indication information is sent, the method further includes: sending third indication information, the third indication information being used to indicate that the terminal device changes from the first state to an RRC idle state; releasing RRC connection between the network device and the terminal device, and deleting context information of the terminal device.

[0060] In a possible implementation manner, after the first indication information is sent, the method further includes: sending fourth indication information, the fourth indication information being used to indicate that the terminal device changes from the first state to an RRC inactive state.

[0061] Optionally, the fourth indication information is sent when one or more of the following conditions are met: a service data volume of the downlink service corresponding to the terminal device meets a data volume limit condition of SDT; a change trend of the service data volume is a downward trend; and a service duration meets a transmission duration limit condition of SDT.

[0062] In a possible implementation manner, after the fourth indication information is sent, the method further includes: sending fifth indication information, the fifth indication information being used to indicate that the terminal device changes from the RRC inactive state to the first state.

[0063] Optionally, the fifth indication information is sent when one or more of the following conditions are met: the service data volume of the downlink service corresponding to the terminal device no longer meets the data volume limit condition of SDT transmission; the change trend of the service data volume is an upward trend; and the service duration does not meet the transmission duration limit condition of SDT.

[0064] In a possible implementation manner, the fifth indication information is sent by: sending a first message and a first reference signal sent along with the first message, the fifth indication information being included in the first message, and the first reference signal being used for time-frequency synchronization.

[0065] In a possible implementation manner, the method further includes: receiving an uplink message in a network access procedure initiated by the terminal device based on the first message, the uplink message including channel measurement results, and the channel measurement results being obtained based on the first reference signal.

[0066] In a possible implementation manner, the method further includes: receiving an uplink message in a network access procedure initiated by the terminal device based on the first message and a second reference signal, the second reference signal being used for requesting access to a network and for channel measurement.

[0067] In a possible implementation manner, the sending the fifth indication information comprises: receiving a second message, the second message being used for requesting to change from the RRC inactive state to the first state; and sending a third message in response to the second message, the third message comprising the fifth indication information.

[0068] In a possible implementation manner, after the sending the fourth indication information, the method further comprises: sending sixth indication information, the sixth indication information being used for indicating to receive data on a first time-frequency resource; and the first time-frequency resource being a resource configured for a terminal device in the first state to perform data transmission.

[0069] In a possible implementation manner, the method further comprises: sending context information of the terminal device to a target network device, the target network device being a network device corresponding to a target cell determined by the terminal device based on cell reselection.

[0070] In a possible implementation manner, the aperiodic reference signal is a reference signal sent along with a channel.

[0071] In a possible implementation manner, the method further comprises: sending downlink data and a reference signal sent along with the downlink data; and receiving a measurement result, the measurement result being obtained based on measurement on the reference signal.

[0072] In a sixth aspect, a communication method is provided, which can be applied to a network device. The method comprises: sending second indication information, the second indication information being used for indicating a terminal device to change from a first state to an RRC connected state; and resuming an RRC connection with the terminal device.

[0073] In a possible implementation manner, the method further comprises: receiving service information corresponding to the terminal device; and determining, according to the service information, to change the terminal device from the first state to the RRC connected state.

[0074] In a possible implementation manner, the method further comprises: receiving state change tendency information of the terminal device, the state change tendency information indicating the RRC connected state; and determining, according to the state change tendency information, to change the terminal device from the first state to the RRC connected state.

[0075] In a possible implementation manner, the method further comprises: resuming to send a periodic reference signal to the terminal device; and / or, resuming to measure the periodic reference signal sent to the terminal device.

[0076] In a seventh aspect, a communication method is provided, which can be applied to a network device. The method comprises: sending fifth indication information, the fifth indication information being used to indicate that a terminal device changes from an RRC inactive state to a first state. In the first state, an RRC connection with the network device is released, and measurement on aperiodic transmission reference signals is started.

[0077] Optionally, the fifth indication information is sent when one or more of the following conditions are met: a service data volume of a downlink service corresponding to the terminal device no longer meets a data volume limit condition for SDT transmission; a change trend of the service data volume is an upward trend; and a service duration does not meet a transmission duration limit condition for SDT.

[0078] In a possible implementation, the sending of the fifth indication information comprises: sending a first message and a first reference signal sent along with the first message, the first message comprising the fifth indication information, and the first reference signal being used for time-frequency synchronization.

[0079] In a possible implementation, the method further comprises: receiving an uplink message in a network access procedure initiated by the terminal device based on the first message, the uplink message comprising a channel measurement result, and the channel measurement result being obtained based on the first reference signal.

[0080] In a possible implementation, the method further comprises: receiving an uplink message and a second reference signal in a network access procedure initiated by the terminal device based on the first message, the second reference signal being used for requesting access to a network and for channel measurement.

[0081] In a possible implementation, the sending of the fifth indication information comprises: receiving a second message, the second message being used to request a change from the RRC inactive state to the first state; and sending a third message in response to the second message, the third message comprising the fifth indication information.

[0082] In a possible implementation, the method further comprises: sending context information of the terminal device to a target network device, the target network device being a network device corresponding to a target cell determined by the terminal device based on cell reselection.

[0083] In a possible implementation, the aperiodic transmission reference signal is a reference signal sent along with the first message.

[0084] In a possible implementation, in the first state, the method further comprises: sending downlink data and a reference signal sent along with the downlink data; and receiving a measurement result, the measurement result being obtained based on measurement on the reference signal.

[0085] In an eighth aspect, a communication method is provided, which can be applied to a network device. The method comprises: sending sixth indication information, the sixth indication information being used to indicate that data is received on a first time-frequency resource; and the first time-frequency resource is a resource configured for a terminal device in a first state to perform data transmission.

[0086] In a possible implementation, the method further comprises: sending context information of the terminal device to a target network device corresponding to a target cell determined by the terminal device based on cell reselection.

[0087] In a possible implementation, the aperiodic reference signal is a reference signal transmitted along with a channel.

[0088] In a possible implementation, in the first state, the method further comprises: sending downlink data and a reference signal transmitted along with the downlink data; and receiving a measurement result, the measurement result being obtained based on measurement on the reference signal.

[0089] In a ninth aspect, a communication apparatus is provided, which comprises units or modules for performing the method in any one of the first aspect to the eighth aspect.

[0090] In a tenth aspect, a communication apparatus is provided, which comprises one or more processors configured to perform the method in any one of the first aspect to the eighth aspect.

[0091] In an eleventh aspect, a readable storage medium is provided, which stores a program or instructions, when the program or instructions are run on an apparatus, the apparatus is caused to perform the method in any one of the first aspect to the eighth aspect.

[0092] In a twelfth aspect, a chip system is provided, which comprises a processor configured to support a computer apparatus to implement the method in any one of the first aspect to the eighth aspect.

[0093] In a thirteenth aspect, a computer program product is provided, which comprises a program; when the computer program is run on a computer, the computer is caused to perform the method in any one of the first aspect to the eighth aspect.

[0094] In a fourteenth aspect, a communication system is provided, including a network device and a terminal device, the terminal device performing the method of any one of the first aspect, the network device performing the method of any one of the fifth aspect; or the terminal device performing the method of any one of the second aspect, the network device performing the method of any one of the sixth aspect; or the terminal device performing the method of any one of the third aspect, the network device performing the method of any one of the seventh aspect; or the terminal device performing the method of any one of the fourth aspect, the network device performing the method of any one of the eighth aspect. BRIEF DESCRIPTION OF DRAWINGS

[0095] FIG. 1 is a schematic diagram of an architecture of a communication system to which embodiments of the present application are applied;

[0096] FIG. 2 is a schematic diagram of a protocol stack of a RAN node in an embodiment of the present application;

[0097] FIG. 3 is a schematic diagram of an O-RAN structure in an embodiment of the present application;

[0098] FIG. 4 is a schematic diagram of state transitions between an RRC connected state, an RRC idle state and an RRC inactive state in an embodiment of the present application;

[0099] FIG. 5 is a schematic diagram of state transitions between an RRC connected state, an RRC idle state and an H-EDT state in an embodiment of the present application;

[0100] FIG. 6 is a schematic diagram of state transitions between an RRC connected state, an RRC idle state, an RRC inactive state and an H-EDT state in an embodiment of the present application;

[0101] FIG. 7 is a schematic diagram of a procedure in which a terminal device changes from an RRC connected state to an H-EDT state in an embodiment of the present application;

[0102] FIG. 8 is a schematic diagram of a procedure in which a terminal device changes from an H-EDT state to an RRC connected state in an embodiment of the present application;

[0103] FIG. 9 is a schematic diagram of a procedure in which a terminal device changes from an H-EDT state to an RRC idle state in an embodiment of the present application;

[0104] FIG. 10 is a schematic diagram of a procedure in which a terminal device changes from an H-EDT state to an RRC inactive state in an embodiment of the present application;

[0105] FIG. 11 is a schematic diagram of a procedure in which a terminal device changes from an RRC inactive state to an H-EDT state in an embodiment of the present application;

[0106] FIG. 12 is a flowchart of a process of changing a terminal device from an RRC inactive state to an H-EDT state determined by a network device according to an embodiment of the present application;

[0107] FIG. 13 is a flowchart of a process of changing a terminal device from an RRC inactive state to an H-EDT state determined by a terminal device according to an embodiment of the present application;

[0108] FIG. 14 is a flowchart of a process of changing a terminal device from an RRC inactive state to an H-EDT state implicitly indicated by a network device according to an embodiment of the present application;

[0109] FIG. 15 is a schematic diagram of a structure of a communication apparatus according to an embodiment of the present application;

[0110] FIG. 16 is a schematic diagram of a structure of another communication apparatus according to an embodiment of the present application. DETAILED DESCRIPTION

[0111] Embodiments of the present application can be applied to various communication systems, such as a global system for mobile communications (GSM) system, a code division multiple access (CDMA) system, a wideband code division multiple access (WCDMA) system, a general packet radio service (GPRS), a long term evolution (LTE) system, an LTE frequency division duplex (FDD) system, an LTE time division duplex (TDD), a universal mobile telecommunication system (UMTS), a worldwide interoperability for microwave access (WIMAX) communication system, a 5th generation (5G) system or a new radio (NR), or a future communication system or other similar communication system.

[0112] Referring to FIG. 1, there is shown a schematic diagram of an architecture of a communication system 1000 to which embodiments of the present application can be applied. As shown in FIG. 1, the communication system includes a radio access network 100 and a core network 200. Optionally, the communication system 1000 can further include an Internet 300. The radio access network 100 can include at least one radio access network device (e.g., 110a and 110b in FIG. 1) and at least one terminal device (e.g., 120a-120j in FIG. 1). The terminal devices are connected to the radio access network devices by radio means, and the radio access network devices are connected to the core network by wire or radio means. The core network device and the radio access network device can be independent and different physical devices, or can be integrated into the same physical device with the functions of the core network device and the logical functions of the radio access network device, or can be a physical device integrated with part of the functions of the core network device and part of the functions of the radio access network device. The terminal devices and the terminal devices, and the radio access network devices and the radio access network devices can be connected to each other by wire or wireless means. FIG. 1 is only a schematic diagram, and the communication system can further include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in FIG. 1.

[0113] The network devices and the terminal devices can be fixed in position or mobile. The network devices and the terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can be deployed on water; can be deployed on airplanes, balloons and artificial satellites. The embodiments of the present application do not limit the application scenarios of the network devices and the terminal devices.

[0114] The roles of the network devices and the terminal devices can be relative, for example, the helicopter or the unmanned aerial vehicle 120i in FIG. 1 can be configured as a mobile network device, and for those terminal devices 120j accessing the radio access network 100 through 120i, the unmanned aerial vehicle 120i is a network device; but for the network device 110a, 120i is a terminal device, that is, 110a and 120i communicate with each other through a wireless air interface protocol. Of course, 110a and 120i can also communicate with each other through an interface protocol between network devices and network devices, at this time, relative to 110a, 120i is also a network device. Therefore, the network devices and the terminal devices can be collectively referred to as communication apparatuses, 110a and 110b in FIG. 1 can be referred to as communication apparatuses with network device functions, and 120a-120j in FIG. 1 can be referred to as communication apparatuses with terminal device functions.

[0115] The network device and the terminal device, the network device and the network device, the terminal device and the terminal device can communicate through the licensed spectrum, or through the unlicensed spectrum, or through the licensed spectrum and the unlicensed spectrum simultaneously; can communicate through the spectrum below 6 gigahertz (GHz), or through the spectrum above 6 GHz, or through the spectrum below 6 GHz and the spectrum above 6 GHz simultaneously. The embodiments of the present application do not limit the spectrum resources used for wireless communication.

[0116] In the embodiments of the present application, the functions of the network device can also be executed by a module (such as a chip) in the network device, or by a control subsystem containing the functions of the network device. The control subsystem containing the functions of the network device herein can be a control center in the above-mentioned application scenarios such as smart grid, industrial control, intelligent transportation, and smart city. The functions of the terminal device can also be executed by a module (such as a chip or a modem) in the terminal device, or by a device containing the functions of the terminal device.

[0117] In the embodiments of the present application, the network device sends a downlink signal or downlink information to the terminal device, and the downlink information is carried on a downlink channel; the terminal device sends an uplink signal or uplink information to the base station, and the uplink information is carried on an uplink channel. In order to communicate with the network device, the terminal device needs to establish a wireless connection with a cell controlled by the network device. The cell that establishes a wireless connection with the terminal device is called the service cell of the terminal device.

[0118] The terminal device 120a-120j can be a terminal device, a user equipment (UE), a mobile station, a mobile terminal, an access terminal, a UE unit, a UE station, a mobile station, a remote station, a remote terminal, a mobile device, a UE terminal, a terminal, a wireless communication device, a multimedia device, a streaming device, a UE agent, or a UE apparatus, etc. The access terminal can be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device, or other processing device connected to a wireless modem, a vehicle, a vehicle-mounted device, a wearable device, a drone, a helicopter, an airplane, a ship, a robot, a mechanical arm, a smart home device, a terminal device in a future 5G network, or a terminal device in a future evolved public land mobile network (PLMN) network, etc. The terminal device can be widely applied to various scenarios, such as device-to-device (D2D), vehicle to everything (V2X) communication, machine-type communication (MTC), internet of things (IOT), virtual reality, augmented reality, industrial control, automatic driving, remote medical treatment, smart power grid, smart home, smart office, smart wear, smart transportation, smart city, etc. Embodiments of the present application do not limit the specific technology and specific device form of the terminal device.

[0119] The wireless access network device can also be referred to as an access network device, a RAN, a RAN entity or a RAN node, or an access node, etc., which constitutes a part of the communication system, helps the terminal device to realize wireless access, and can communicate with the terminal device. The multiple RANs in the communication system 1000 can be nodes of the same type or nodes of different types.

[0120] The RAN node can be a base station, an evolved NodeB (eNodeB), a relay station, an access point (AP), a transmission reception point (TRP), a next generation NodeB (gNB), a base station in a future mobile communication system, an access node in a wireless fidelity (Wi-Fi) system, or an access network device in a future evolved PLMN network, etc. The RAN node can be a macro base station (e.g., 110a in FIG. 1), a micro base station or an indoor station (e.g., 110b in FIG. 1), a relay node or a donor node, or a wireless controller in a cloud radio access network (CRAN) scenario, or an open RAN (O-RAN or ORAN). Optionally, the RAN node can also be a server, a wearable device, a vehicle or a vehicle-mounted device, etc. For example, the access network device in vehicle to everything (V2X) technology can be a road side unit (RSU).

[0121] The RAN node can be applied to a 3rd generation partnership project (3GPP)-related cellular system, such as a 4G or 5G mobile communication system, a non-terrestrial network (NTN) system, or a future-oriented evolved system (e.g., a 6G mobile communication system), and can also be applied to a communication system in which two or more of the above systems are fused.

[0122] In the NTN system, the RAN node can be in a transparent mode or a regenerative mode, and the corresponding cell can be an earth fixed cell or an earth moving cell.

[0123] The communication between the access network device and the terminal device follows a certain protocol layer structure. The protocol layer can include a control plane protocol layer and a user plane protocol layer. The control plane protocol layer can include at least one of a radio resource control (RRC) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, a media access control (MAC) layer, or a physical (PHY) layer, etc. The user plane protocol layer can include at least one of a service data adaptation protocol (SDAP) layer, a PDCP layer, an RLC layer, a MAC layer, or a PHY layer, etc.

[0124] In a scenario where a plurality of RAN nodes cooperate to assist a terminal device to implement wireless access, different RAN nodes can respectively implement part of the functions of a base station. For example, as shown in (a) of FIG. 2, the RAN node can be a central unit (CU), a distributed unit (DU), and can also be a radio unit (RU), etc. For another example, as shown in (b) of FIG. 2, the CU can be split into a CU-control plane (CP) and a CU-user plane (UP). The CU and the DU can be separately arranged, or can also be included in the same network element, such as a baseband unit (BBU). The CU and the DU split the protocol layers of the RAN node, and the functions of part of the protocol layers are controlled by the CU, and the functions of the remaining part or all of the protocol layers are distributed in the DU and controlled by the CU. As an implementation manner, the CU is deployed with the RRC layer, the SDAP layer and the PDCP layer in the protocol stack; the DU is deployed with the RLC layer, the MAC layer and the PHY layer in the protocol stack. Based on the above deployment, the CU has the processing capability of RRC, PDCP and SDAP. The DU has the processing capability of RLC, MAC and PHY.

[0125] It can be understood that the above-mentioned splitting of functions is only an example and does not constitute a limitation on the CU and the DU. The RU can be included in a radio frequency device or a radio frequency unit, such as a remote radio unit (RRU), an active antenna unit (AAU) or a remote radio head (RRH).

[0126] O-RAN aims to realize an intelligent and open access network. The main feature of the O-RAN architecture is the separation of software and hardware, which can realize the virtualization of network functions and the standardization of hardware. In addition, the O-RAN also introduces artificial intelligence (AI).

[0127] FIG. 3 shows an O-RAN architecture diagram. In the O-RAN system, the CU can also be referred to as O-CU (open CU), the DU can also be referred to as O-DU, the CU-CP can also be referred to as O-CU-CP, the CU-UP can also be referred to as O-CU-UP, and the RU can also be referred to as O-RU. In different systems, the CU (or CU-CP and CU-UP), DU or RU can also have different names, and those skilled in the art can understand their meanings. Any one of the CU (or CU-CP, CU-UP), DU and RU in the embodiment of the present application can be realized by a software module, a hardware module, or a combination of a software module and a hardware module.

[0128] For the correspondence between the network elements (or nodes) in the O-RAN system and the protocol layer functions that can be implemented, refer to Table 1.

[0129] Table 1: Correspondence between network elements of O-RAN and protocol layer functions that can be implemented

[0130] In the system control plane protocol stack, the protocol layer below the RRC layer is called the access layer (AS), and the protocol layer above the RRC layer is called the non-access layer (NAS). In simple terms, the AS process refers to a process that needs to be processed by the terminal device and the base station; the NAS process refers to a process that needs to be processed by the terminal device and the core network, and the base station only forwards and does not process. Different protocol layers define different layer states, such as NAS layer states and RRC layer states. Generally speaking, mobility management is usually based on the RRC layer state of the terminal device (hereinafter referred to as RRC state).

[0131] The RRC state of the terminal device reflects the AS connection of the terminal device, and the AS connection refers to the signaling connection between the terminal device and the base station. The AS signaling interaction can establish a signaling path between the terminal device and the core network, and based on the signaling path, the NAS signaling interaction between the terminal device and the core network can be ensured.

[0132] In the current communication protocol, terminal devices have different states, and different RRC states can be converted. FIG. 4 shows an RRC state conversion diagram. As shown in FIG. 4, the terminal device in the RRC connected state initiates an RRC connection release procedure according to the received RRC connection release message, and switches to the RRC idle state or the RRC inactive state. The terminal device in the RRC idle state or the RRC inactive state switches to the RRC connected state through a random access procedure. For the terminal device in the RRC connected state, if the RRC connection release message contains suspendConfig, the terminal device enters the RRC inactive state after RRC connection release, and if the RRC connection release message does not contain suspendConfig, the terminal device enters the RRC idle state after RRC connection release. The suspendConfig carries the inactive-radio network temporary identity (I-RNTI), RAN-NotificationAreaInfo, RAN paging cycle, T380 timer, and other contents, and is used for RRC inactive state paging, RAN-based notification area (RNA) update, and other processes.

[0133] In order to ensure data transmission efficiency while saving energy, the embodiments of the present application provide a communication method and related devices that can implement the method. The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0134] The embodiments of the present application provide a new RRC state, referred to as the first state in the following embodiments, for the first state. In the first state, the terminal device releases the RRC connection with the network and can perform data transmission. Compared with the RRC inactive state, the terminal device in the first state can obtain better data transmission efficiency. Compared with the RRC connected state, the terminal device in the first state can obtain better energy saving effect.

[0135] Based on the above description of the first state, in one possible manner, the first state can be regarded as an enhanced RRC inactive state, and the first state has higher data transmission performance on the basis of the RRC inactive state. Alternatively, the first state can be referred to as a high-efficiency data transmission (H-EDT) state. It should be understood that the first state can also be referred to as an "enhanced RRC inactive state", an "RRC inactive state with high-efficiency data transmission", an "INACTIVE state with H-EDT", and the like. The naming of the new RRC state is not limited in the present application. For the convenience of description, the first state is taken as an H-EDT state in the following description.

[0136] When the terminal device is in the H-EDT state, the RRC connection between the terminal device and the network device is released, but the network device stores the context information of the terminal device, so the terminal device in the H-EDT state is still in the CM state, that is, the terminal device still has a signaling connection with the core network element (such as the AMF), and therefore the terminal device in the H-EDT state can quickly restore the RRC connection and perform data transmission with the network side when there is a data transmission requirement.

[0137] Alternatively, when the terminal device is in the H-EDT state, the context information of the terminal device stored by the network device is the same as or substantially the same as the context information of the terminal device stored by the network device when the terminal device is in the RRC inactive state. For example, the network device stores more terminal device context information for the terminal device in the H-EDT state than for the terminal device in the RRC inactive state. Alternatively, the additional context information includes at least one of a data plane integrity key K_{UP,int}, a data plane encryption key K_{UP,enc}, and a control plane encryption key K_{CP,enc}. In the terminal device context information stored by the network device for the terminal device in the current RRC inactive state, only the control plane integrity key K_{RRC,int} is retained.

[0138] The terminal device in the H-EDT state has one or more of the following characteristics:

[0139] (1) Transmission is not limited

[0140] Compared with the SDT transmission of the terminal device in the RRC inactive state with a time limit, the data transmission of the terminal device in the H-EDT state with the network side can have no time limit.

[0141] Optionally, compared with the terminal device in the RRC inactive state, the terminal device in the H-EDT state can perform SDT transmission without a data packet size limit.

[0142] (2) No limit on the bearer

[0143] When the terminal device in the H-EDT state performs data transmission with the network side, there can be no DRB limit. For example, the terminal device in the H-EDT state can forward data or signaling to the core network or receive data or signaling from the core network based on the DRB or SRB configured for the H-EDT state in advance, or the terminal device in the H-EDT state can also forward data or signaling to the core network or receive data or signaling from the core network based on other DRBs or SRBs.

[0144] Optionally, the terminal device in the H-EDT state can also use some suspended DRBs (DRB suspend) as DRBs used in the H-EDT state for data transmission.

[0145] (3) Context information can be migrated between network devices

[0146] For the terminal device in the H-EDT state, if it migrates from a source cell to a target cell (for example, by selecting to reside in the target cell through cell reselection), the context information of the terminal device can be transferred from the network device corresponding to the source cell to the network device corresponding to the target cell along with the movement of the terminal device, so that the context information of the terminal device is saved in the network device where the terminal device resides, and the network device where the terminal device currently resides can directly instruct the terminal device to perform data transmission through L1 signaling or L2 signaling. In this way, for the terminal device in the H-EDT state that has migrated from the source cell to the target cell, when performing data transmission in the target cell, since the context information of the terminal device has been stored in the network device corresponding to the target cell, there is no need to perform the operation of obtaining the context information of the terminal device from the network device corresponding to the source cell, thereby improving the data transmission efficiency.

[0147] (4) Channel measurement based on aperiodically transmitted reference signals

[0148] When the terminal device is in the H-EDT state, it does not need to detect the periodically transmitted downlink reference signals of the network side, that is, it does not need to perform channel measurement based on the periodically transmitted downlink reference signals. Correspondingly, the network device can also not transmit periodic downlink reference signals for the terminal device in the H-EDT state.

[0149] Optionally, the terminal device in the H-EDT state also does not need to send a periodic uplink reference signal to the network side. Correspondingly, the network device can also not need to perform channel measurement based on the periodic uplink reference signal for the terminal device in the H-EDT state.

[0150] For the terminal device in the H-EDT state, the network device can send an aperiodic reference signal, and correspondingly, the terminal device can receive the aperiodic reference signal sent by the network device, perform channel measurement based on the reference signal, and use the result of the channel measurement to select appropriate resources for subsequent data transmission.

[0151] In a possible implementation, the aperiodic reference signal is a reference signal sent by the network device along with a path. For example, the reference signal is sent along with downlink data. For example, the network device can send downlink data (data carried by a PDSCH, including a paging message or data) and a reference signal sent along with the downlink data. For another example, the reference signal is sent along with control signaling. For another example, downlink control signaling sent by the network device can be used as an aperiodic reference signal. The downlink data (or control signaling) and the reference signal sent along with the path can be sent on the same channel or different channels, which is not limited in the present application.

[0152] For example, taking the reference signal sent along with the downlink data as an example, the network device can send the reference signal to the terminal device in the H-EDT state on a channel along with the path. The channel along with the path shares the same physical channel as a service channel used to transmit service data. For example, in one implementation of sending the downlink reference signal along with the downlink data, the network device transmits the downlink data and the reference signal on different time-frequency resources on a PDSCH. For example, the network device sends the downlink reference signal on part of the frequency domain resources on the first symbol or the first two symbols in the time-frequency resources corresponding to the PDSCH, and the remaining time-frequency resources are used to carry the downlink data. That is, the downlink reference signal occupies part of the resources of the downlink data channel. For example, the reference signal sent along with the path can be a CSI-RS.

[0153] For example, the network device sends downlink control signaling and downlink reference signals along with the downlink control signaling. The downlink control signaling can be a paging message or an activation message or a wake-up message, and the downlink reference signal can be a tracking reference signal (channel status information reference signal for tracking, TRS). Optionally, the time domain positions of the downlink control signaling and the downlink reference signal satisfy certain rules, for example, there is at least one TRS in a first time window before the paging occasion, and the time interval between the paging occasion and the first time window can be one or two slots. The time domain position of the TRS can be determined according to the time domain position of the paging occasion.

[0154] The present application does not limit the implementation of the downlink reference signal sent along with the data. The terminal device in the H-EDT state can monitor the downlink reference signal sent along with the downlink data by the network side, and can perform channel measurement based on the downlink reference signal, and send the measurement result to the network side to improve the transmission efficiency of subsequent data transmission.

[0155] Compared with not monitoring and measuring the reference signal when the terminal device in the RRC inactive state performs SDT transmission, the terminal device in the H-EDT state measures the downlink reference signal sent along with the data, and can select appropriate bandwidth resources based on channel measurement to perform data transmission with the network side, thereby improving the data transmission efficiency.

[0156] Since the network device only sends downlink data and reference signals sent along with the data to the terminal device in the H-EDT state when there is a data transmission demand, and the terminal device measures the reference signals sent along with the data, compared with the terminal device in the RRC connected state which needs to monitor and measure the periodic downlink reference signal, the terminal device in the H-EDT state can reduce power consumption.

[0157] (5) Measurement relaxation

[0158] The terminal device in the H-EDT state can receive reference signals periodically sent by the current cell and neighboring cells, and can determine whether to perform cell reselection according to the signal reception strength. For example, the reference signal can be a synchronization signal block (SSB).

[0159] Optionally, compared with the terminal device in the RRC inactive state or the terminal device in the RRC connected state, the terminal device in the H-EDT state can monitor the reference signals of the current cell and the neighboring cells in a longer period, so as to determine whether to perform cell reselection according to factors such as signal receiving strength. Since the terminal device in the H-EDT state monitors and measures the reference signals of the current cell and the neighboring cells in a longer period, compared with the terminal device in the RRC connected state or the terminal device in the RRC inactive state, the power consumption of the terminal device can be saved.

[0160] For example, the measurement period of the terminal device in the H-EDT state for the reference signals of the current cell and the neighboring cells is a first period, and the measurement period of the terminal device in the RRC connected state or the terminal device in the RRC inactive state for the reference signals of the current cell and the neighboring cells is a second period. The length of the first period is greater than the length of the second period.

[0161] In a possible implementation, the length of the first period can be preconfigured or configured by the network side.

[0162] In another possible implementation, the first period can be determined based on a measurement relaxation factor and the length of the second period. For example, the measurement relaxation factor can be multiplied by the length of the second period to obtain the length of the first period. For example, the measurement relaxation factor can be a parameter with a value greater than 1, and more specifically, can be an integer greater than 1, so that the length of the first period is an integer multiple of the length of the second period.

[0163] It should be understood that the “measurement relaxation factor” can also be referred to as a “correction factor” or an “adjustment factor”, and the naming of this parameter in the present application is not limited.

[0164] Optionally, the measurement relaxation factor can be preconfigured or configured by the network side to the terminal device. For example, the network device can send the measurement relaxation factor to the terminal device in a message used to instruct the terminal device to change to the H-EDT. For another example, the network device can include the measurement relaxation factor in a system message sent by the network device.

[0165] (6) Multi-port random access channel (RACH)

[0166] Different from the current single-port RACH, random access is performed by using multiple ports, so that the network can obtain more channel information corresponding to the ports, and in subsequent scheduling, the multi-stream mode can be used to improve the transmission rate of the terminal device. Specifically, the current RACH is a single port, which is mainly considered because the current RACH process does not bear the function of channel measurement. The msg1 sent by the terminal device in the random access process (RACH process) is a preamble sequence, and the purpose is to enable the network to perform time advanced (TA) measurement. Therefore, even in the current random access process with SDT (RACH with SDT), after receiving msg2, the terminal device sends uplink data using a low-order modulation and coding scheme (MCS) (for example, MCS = 0). In the H-EDT state, the msg1 (not limited to the preamble sequence, but can be another sequence, but can achieve the purpose of channel measurement) sent by the terminal device in the random access process can enable the network to perform channel measurement, so the network can use high-order MCS to schedule data when scheduling the terminal device subsequently. Further, through the multi-port RACH process, the network can obtain the channel information of multiple ports of the terminal device, so the network can not only use high-order MCS, but also use multi-stream to schedule data when scheduling the terminal device subsequently, further improving the transmission rate.

[0167] In a possible implementation manner, the related parameters of the H-EDT state (for example, the related parameters including the conditions to be met by the terminal device when entering the H-EDT state, and the like) can be configured in combination with the service characteristics of the terminal device, so as to provide on-demand mobility management for the terminal device. Optionally, the network can configure the related parameters of the H-EDT state in combination with the characteristics and requirements of the service of the terminal device, the assistance information provided by the core network, and the historical mobility of the terminal device. For example, the H-EDT state can be configured according to the QoS class identifier (QCI; QoS is the abbreviation of quality of service) of the terminal device.

[0168] For example, the related parameters of the conditions to be met by the terminal device when entering the H-EDT state can include one or more of the following:

[0169] - data volume threshold: when the total data volume of the service corresponding to the terminal device is less than or equal to the data volume threshold, the terminal device can change from the RRC connected state to the H-EDT state;

[0170] - a time threshold: the terminal device can change from the RRC connected state to the H-EDT state when the duration of the service corresponding to the terminal device is less than or equal to the time threshold;

[0171] - a service type: the terminal device can change from the RRC connected state to the H-EDT state when the type of the service corresponding to the terminal device is the service type indicated by the “service type” parameter. Optionally, the service type indicated by the “service type” parameter can be a service with less data volume, or a service with shorter duration, or a service with lower requirement for log transmission efficiency, for example, an Internet of Things service, a short message service, a voice service, or a signaling data transmission service, which is not limited in the present application.

[0172] - a QoS level threshold: the terminal device can change from the RRC connected state to the H-EDT state when the QoS level of the service corresponding to the terminal device matches the QoS level indicated by the “QoS level threshold” parameter, for example, the QoS level of the service corresponding to the terminal device is lower than or equal to the QoS level threshold (the higher the QoS level, the higher the requirement for log transmission reliability).

[0173] It can be understood that all or part of the above parameters can also be agreed by the system. The configuration mode of the above parameters is not limited in the present application.

[0174] In a possible implementation manner, the RRC state of the terminal device can include the RRC connected state, the RRC idle state, and the H-EDT state. That is, the H-EDT state in the present application is used to replace the RRC inactive state in the current NR. In another possible implementation manner, the RRC state of the terminal device can include the RRC connected state, the RRC idle state, the RRC inactive state, and the H-EDT state. That is, the H-EDT state is introduced in addition to the three states in the existing NR. The terminal device can be converted between different RRC states. FIG. 5 shows a schematic diagram of conversion between different RRC states when the RRC state includes the RRC connected state, the RRC idle state, and the H-EDT state, and FIG. 6 shows a schematic diagram of conversion between different RRC states when the RRC state includes the RRC connected state, the RRC idle state, the RRC inactive state, and the H-EDT state.

[0175] As shown in FIGS. 5 and 6, the terminal device in the RRC connected state releases the RRC connection, starts measurement on the non-periodically transmitted reference signal, and stops measurement on the periodically transmitted reference signal, thereby entering the H-EDT state. The terminal device in the H-EDT state resumes the RRC connection, starts measurement on the periodically transmitted reference signal, and stops measurement on the non-periodically transmitted reference signal, thereby entering the RRC connected state. For the terminal device in the H-EDT state, the network side deletes the context of the terminal device, thereby making the terminal device enter the RRC idle state.

[0176] The terminal device in the H-EDT state stops measuring the aperiodically transmitted reference signal, and can enter the RRC inactive state. The terminal device in the RRC inactive state starts measuring the aperiodically transmitted reference signal, and can enter the H-EDT state.

[0177] The conversion between the RRC connected state and the RRC idle state, the conversion between the RRC connected state and the RRC inactive state, and the conversion from the RRC inactive state to the RRC idle state can refer to FIG. 4 and the related description.

[0178] The terminal device in the H-EDT state has other characteristics, which can refer to the description above.

[0179] It should be understood that "conversion", "switching", "entry", "release", "change" in the present application are used to describe the change of RRC state, and can be replaced with each other. For example, the conversion from the RRC connected state to the RRC inactive state can be expressed as "transition from RRC_CONNECTED to RRC_INACTIVE".

[0180] It should be understood that "stop", "suspend", "suspend", "suspend", "pause", "cancel" or "cancel" in the present application can be replaced with each other. For example, "stopping measuring the aperiodically transmitted reference signal" can also be expressed as "canceling the measurement of the aperiodically transmitted reference signal".

[0181] Based on the system architecture shown in FIG. 1, FIG. 2 or FIG. 3, and the RRC state conversion schematic diagram shown in FIG. 5 or FIG. 6, FIG. 7 shows a flowchart of changing the terminal device from the RRC connected state to the H-EDT state. In the embodiments of the present application, the functions of the network device can also be performed by the modules (such as chips) in the network device, or by the control subsystem containing the functions of the network device. The control subsystem containing the functions of the network device here can be the control center in the above application scenarios such as smart grid, industrial control, intelligent transportation, and smart city. The functions of the terminal device can also be performed by the modules (such as chips or modems) in the terminal device, or by the device containing the functions of the terminal device.

[0182] As shown in FIG. 7, the flowchart can include the following steps:

[0183] Step 701: The terminal device in the RRC connected state sends service information and / or state change tendency information to the network device.

[0184] The service information can include service information of an uplink service or service information of a downlink service, and the service information and the state change tendency information can be used to make a decision on the RRC state change.

[0185] Optionally, the service information can include one or more of the following: service data volume, change trend of service data volume (used to reflect the distribution of data volume over time, for example, gradually increasing or gradually decreasing), service duration, service type, QoS level, etc. The network device can determine whether to change the terminal device from the RRC connected state to the H-EDT state according to the service information reported by the terminal device.

[0186] The "service data volume" can be estimated by the terminal device according to the service type. The corresponding service data volume can be different according to different service types, for example, the service data volume of machine type communication (MTC) or ultra reliable low latency communication (URLLC) service is small, while the service data volume of enhanced mobile broadband (eMBB) service or real-time broadband (RTBC) service can be large. The correspondence between the service type and the service data volume can be pre-configured for different service types, so that the terminal device can estimate the corresponding service data volume according to the service type.

[0187] Optionally, the terminal device can obtain the service information based on an AT (attention) command. More specifically, the terminal device can obtain the service information based on the AT command in the case of beam alignment.

[0188] The state change tendency information indicates the terminal device's opinion on the RRC state, or in other words, the state change tendency information can indicate the RRC state suggested or expected by the terminal device. In this process, the RRC state indicated by the state change tendency information is the H-EDT state, indicating that the RRC state suggested by the terminal device is the H-EDT state.

[0189] Optionally, the state change tendency information can be determined by the terminal device based on the service information.

[0190] For example, if the service information meets one or more of the following conditions, the terminal device can suggest changing from the RRC connected state to the H-EDT state:

[0191] Condition 1: the total data volume of the service corresponding to the terminal device is less than or equal to a data volume threshold, indicating that the service volume of the downlink data transmission of the terminal device is small. In this case, in order to reduce the power consumption of the terminal device, the RRC connected state can be changed to the H-EDT state.

[0192] Condition 2: the duration length (i.e., the data transmission time length) of the service corresponding to the terminal device is less than or equal to a time length threshold, indicating that the time length of the downlink data transmission of the terminal device is short. In this case, in order to reduce the power consumption of the terminal device, the RRC connected state can be changed to the H-EDT state.

[0193] Condition 3: the data volume of the service corresponding to the terminal device is in a downward trend, indicating that the data volume of the downlink data transmission of the terminal device is gradually decreasing. In this case, in order to reduce the power consumption of the terminal device, the RRC connected state can be changed to the H-EDT state.

[0194] Condition 4: the type of the service corresponding to the terminal device is a service type specified in the configuration information of the H-EDT state, indicating that the data volume of the downlink transmission of the terminal device is small, or the duration length is short, or the requirement for data transmission efficiency is low. In this case, in order to reduce the power consumption of the terminal device, the RRC connected state can be changed to the H-EDT state.

[0195] Condition 5: the QoS level of the service corresponding to the terminal device is lower than or equal to a QoS level threshold, indicating that the downlink data transmission of the terminal device has a low requirement for data transmission efficiency. In this case, in order to reduce the power consumption of the terminal device, the RRC connected state can be changed to the H-EDT state.

[0196] It should be understood that the above only exemplarily lists several conditions that can cause the terminal device to change from the RRC connected state to the H-EDT state, and the present application does not limit this.

[0197] Optionally, the state change tendency information can include indication information of the RRC state to which the terminal device tends, for example, in the present flow, the state change tendency information can be indication information of the H-EDT state.

[0198] Optionally, the state change tendency information can further include first time length information, the first time length information being used to indicate the duration length of the RRC state (here taking the H-EDT state as an example) suggested by the terminal device. The network device can determine the time length during which the terminal device is in the H-EDT state according to the first time length information.

[0199] In a possible implementation, after obtaining the service information, the terminal device can send the service information and / or the state change tendency information to the network device only when a certain condition is met, and the terminal device does not send the service information or the state change tendency information to the network device if the condition is not met. Optionally, the condition can include one or more of the following:

[0200] Condition a: the data amount of the service corresponding to the terminal device is less than a threshold, which can be equal to or different from the data amount threshold described above, and the application does not limit this;

[0201] Condition b: the data amount of the service corresponding to the terminal device has a downward trend;

[0202] Condition c: the duration of the service corresponding to the terminal device is less than or equal to a duration threshold.

[0203] Based on the system architecture shown in FIG. 2, in step 701, the terminal device sends the service information and / or the state change tendency information to the CU (for example, the CU-CP), and the CU can determine whether to change the terminal device from the RRC connected state to the H-EDT state in a subsequent step according to the service information and / or the state change tendency information.

[0204] Based on the system architecture shown in FIG. 3, in step 701, the terminal device sends the service information and / or the state change tendency information to the O-CU (for example, the O-CU-CP), and the O-CU can determine whether to change the terminal device from the RRC connected state to the H-EDT state in a subsequent step according to the service information and / or the state change tendency information.

[0205] Step 701 is an optional step.

[0206] Step 702: The network device determines to change the RRC state of the terminal device from the RRC connected state to the H-EDT state.

[0207] In a possible implementation, the network device can determine whether to change the terminal device from the RRC connected state to the H-EDT state according to the service information sent by the terminal device. The network device can refer to the method of the terminal device for determining whether to change from the RRC connected state to the H-EDT state according to the service information.

[0208] In another possible implementation, the network device can determine to change the terminal device from the RRC connected state to the RRC state indicated by the state change tendency information according to the state change tendency information sent by the terminal device.

[0209] In another possible implementation, the network device can determine to change the terminal device from the RRC connected state to the H-EDT state according to service information corresponding to the terminal device obtained from the core network. The content included in the service information can refer to the related description of the service information in step 701.

[0210] In another possible implementation, the network device can determine to change the terminal device from the RRC connected state to the H-EDT state according to the data volume or the data volume change trend of the service data corresponding to the terminal device received from the core network. For example, if the network device determines that the data volume of the service corresponding to the terminal device is less than or equal to a data volume threshold, the network device decides to change the terminal device from the RRC state to the H-EDT state. For another example, if the network device determines that the data volume change trend of the service corresponding to the terminal device is a downward trend, the network device decides to change the terminal device from the RRC connected state to the H-EDT state.

[0211] Taking the system architecture shown in FIG. 2 as an example, the CU at the RAN side receives downlink data, and the CU sends the data to the DU. When the CU sends the data to the DU, indication information is added in the F1 signaling, which is used to indicate that the change trend of the buffered data volume is downward, or used to indicate that the H-EDT state is changed. After the DU receives the indication information, the DU sends L1 signaling or L2 signaling to the terminal device, so as to indicate that the terminal device is changed from the RRC connected state to the H-EDT state.

[0212] Taking the system architecture shown in FIG. 3 as an example, the O-CU (for example, O-CU-UP) at the RAN side receives downlink data, and the O-CU sends the data to the O-DU. When the O-CU sends the data to the O-DU, indication information is added in the F1 signaling, which is used to indicate that the change trend of the buffered data volume is downward, or used to indicate that the H-EDT state is changed. After the O-DU receives the indication information, the O-DU sends L1 signaling or L2 signaling to the terminal device, so as to indicate that the terminal device is changed from the RRC connected state to the H-EDT state.

[0213] In a possible implementation, after the network device determines to change the terminal device from the RRC connected state to the H-EDT state, or after the network device receives the RRC state change confirmation information sent by the terminal device, the network device can modify the context information of the terminal device saved on the network device, and record the current RRC state of the terminal device as the H-EDT state.

[0214] Step 703: The network device sends first indication information to the terminal device.

[0215] The first indication information is used to indicate that the terminal device is changed from the RRC connected state to the H-EDT state.

[0216] Optionally, the first indication information is carried in L3 signaling. The L3 signaling is sent by an L3 layer (i.e., an RRC layer), for example, the L3 signaling can be an RRC connection release message.

[0217] Optionally, the RRC release message can include indication information for indicating release to the H-EDT state.

[0218] Based on the system architecture shown in FIG. 2, in step 703, the CU (e.g., the CU-CP) in the RAN sends an F1 signaling to the DU, the F1 signaling can include indication information, the indication information can be used to indicate change to the H-EDT state, and the DU sends the first indication information to the terminal device according to the F1 signaling.

[0219] Based on the system architecture shown in FIG. 3, in step 701, the O-CU (e.g., the O-CU-CP) in the RAN sends an F1 signaling to the O-DU, the F1 signaling can include indication information, the indication information can be used to indicate change to the H-EDT state, and the O-DU sends the first indication information to the terminal device according to the F1 signaling.

[0220] In step 704, the terminal device enters the H-EDT state according to the first indication information, in the H-EDT state, the RRC connection between the terminal device and the network device is released, and the measurement on the aperiodic reference signal is started.

[0221] Optionally, the terminal device can further send RRC state change confirmation information to the network device, to notify that the terminal device changes to the H-EDT state.

[0222] In a possible implementation, in the H-EDT state, the terminal device can receive the reference signal sent along with the downlink data, perform channel measurement based on the reference signal, and send the channel measurement result to the network device. The terminal device can also stop receiving the periodic downlink reference signal sent by the network device, and stop sending the periodic uplink reference signal to the network device. Correspondingly, the network device can stop sending the periodic downlink reference signal to the terminal device, and stop detecting the uplink reference signal on the time-frequency resource used by the terminal device to send the periodic uplink reference signal.

[0223] In a possible implementation, in the H-EDT state, the terminal device can receive the reference signal of at least one cell according to a first period, and can perform cell reselection or cell reselection decision based on the reference signal.

[0224] Based on the system architecture shown in FIG. 1, FIG. 2 or FIG. 3, and the RRC state transition diagram shown in FIG. 5 or FIG. 6, FIG. 8 shows a flow diagram of a terminal device changing from an H-EDT state to an RRC connected state. In the embodiments of the present application, the functions of the network device can also be performed by a module (such as a chip) in the network device, or by a control subsystem containing the functions of the network device. The control subsystem containing the functions of the network device herein can be a control center in the above-mentioned application scenarios such as smart grid, industrial control, intelligent transportation, and smart city. The functions of the terminal device can also be performed by a module (such as a chip or modem) in the terminal device, or by a device containing the functions of the terminal device.

[0225] As shown in FIG. 8, the flow can include the following steps:

[0226] Step 801: The terminal device in the H-EDT state sends service information and / or state change tendency information to the network device.

[0227] In this step, the content and the obtaining method of the service information can refer to step 701 in the flow shown in FIG. 7.

[0228] In this step, the RRC state indicated by the state change tendency information is the RRC connected state, indicating that the RRC state suggested by the terminal device is the RRC connected state.

[0229] Optionally, the state change tendency information can be determined by the terminal device based on the service information. For example, if the service information satisfies one or more of the following conditions, the terminal device can suggest changing from the H-EDT state to the RRC connected state:

[0230] Condition 1: The total data volume of the service corresponding to the terminal device is greater than a data volume threshold, indicating that the service volume of the downlink data transmission of the terminal device is large. In this case, in order to ensure the efficiency of data transmission, the terminal device can change from the H-EDT state to the RRC connected state.

[0231] Condition 2: The duration length (i.e., the data transmission time length) of the service corresponding to the terminal device is greater than a time length threshold, indicating that the time length of the downlink data transmission of the terminal device is long. In this case, in order to ensure the efficiency of data transmission, the terminal device can change from the H-EDT state to the RRC connected state.

[0232] Condition 3: The data volume of the service corresponding to the terminal device has an upward trend, indicating that the data volume of the downlink data transmission of the terminal device gradually increases. In this case, in order to ensure the efficiency of data transmission, the terminal device can change from the H-EDT state to the RRC connected state.

[0233] Condition 4: the type of the service corresponding to the terminal device is not the service type specified in the configuration information of the H-EDT state, indicating that the terminal device has a large amount of downlink data transmission, or a long duration, or a high requirement on the efficiency of data transmission. In this case, in order to ensure the efficiency of data transmission, the terminal device can be changed from the H-EDT state to the RRC connected state.

[0234] Condition 5: the QoS level of the service corresponding to the terminal device is higher than the QoS level threshold, indicating that the terminal device has a high requirement on the efficiency of data transmission. In this case, in order to ensure the efficiency of data transmission, the terminal device can be changed from the H-EDT state to the RRC connected state.

[0235] It should be understood that the above only exemplarily lists several conditions that can cause the terminal device to change from the H-EDT state to the RRC connected state, and the present application does not limit this.

[0236] Optionally, the state change tendency information can include indication information of the RRC state to which the terminal device tends, for example, in the present flow, the state change tendency information can be indication information of the H-EDT state.

[0237] Optionally, the state change tendency information can further include second duration information, the second duration information being used to indicate the duration of the RRC state (herein, the RRC connected state is taken as an example) suggested by the terminal device. The network device can determine the duration of the terminal device in the RRC connected state according to the second duration information.

[0238] In a possible implementation, after obtaining the service information, the terminal device can send the service information and / or the state change tendency information to the network device only when a certain condition is met, and if the condition is not met, the terminal device will not send the service information or the state change tendency information to the network device. Optionally, the condition can include one or more of the following:

[0239] Condition a: the data amount of the service corresponding to the terminal device is greater than or equal to a threshold, and optionally, the threshold can be equal to the data amount threshold described above, or can not be equal to the data amount threshold, which is not limited by the present application;

[0240] Condition b: the data amount of the service corresponding to the terminal device has an upward trend;

[0241] Condition c: the duration of the service corresponding to the terminal device is greater than a duration threshold.

[0242] Based on the system architecture shown in FIG. 2, in step 801, the terminal device sends the service information and / or the state change tendency information to the CU (for example, the CU-CP), and the CU can determine whether to change the terminal device from the H-EDT state to the RRC connected state according to the service information and / or the state change tendency information in subsequent steps.

[0243] Based on the system architecture shown in FIG. 3, in step 801, the terminal device sends service information and / or state change tendency information to the O-CU (for example, the O-CU-CP), and the O-CU can determine whether to change the terminal device from the H-EDT state to the RRC connected state according to the service information and / or the state change tendency information in subsequent steps.

[0244] Step 801 is an optional step.

[0245] Step 802: The network device determines to change the RRC state of the terminal device from the H-EDT state to the RRC connected state.

[0246] In a possible implementation, the network device can determine whether to change the terminal device from the H-EDT state to the RRC connected state according to the service information sent by the terminal device. The network device can refer to the method for determining whether to change the terminal device from the H-EDT state to the RRC connected state according to the service information in step 801.

[0247] In another possible implementation, the network device can determine to change the terminal device from the RRC connected state to the RRC state indicated by the state change tendency information according to the RRC state indicated by the state change tendency information sent by the terminal device.

[0248] In another possible implementation, the network device can determine to change the terminal device from the H-EDT state to the RRC connected state according to the service information corresponding to the terminal device obtained from the core network. The content included in the service information can refer to the related description of the service information in step 701.

[0249] In another possible implementation, the network device can determine to change the terminal device from the H-EDT state to the RRC connected state according to the data amount or data amount change trend of the service data corresponding to the terminal device received from the core network. For example, if the network device determines that the data amount of the service corresponding to the terminal device is greater than a data amount threshold, it decides to change the terminal device from the H-EDT state to the RRC connected state. For another example, if the network device determines that the data amount of the service corresponding to the terminal device has an upward trend, it decides to change the terminal device from the H-EDT state to the RRC connected state.

[0250] Taking the system architecture shown in FIG. 2 as an example, the CU on the RAN side receives downlink data, and the CU sends the data to the DU, and adds indication information in the F1 signaling, which is used to indicate that the change trend of the buffered data volume is rising, or is used to indicate that the RRC connected state is changed; after the DU receives the indication information, the DU sends L1 signaling or L2 signaling to the terminal device, so as to indicate that the terminal device is changed from the H-EDT state to the RRC connected state.

[0251] Taking the system architecture shown in FIG. 3 as an example, the O-CU (for example, O-CU-UP) on the RAN side receives downlink data, and the O-CU sends the data to the O-DU, and adds indication information in the F1 signaling, which is used to indicate that the change trend of the buffered data volume is rising, or is used to indicate that the RRC connected state is changed; after the O-DU receives the indication information, the O-DU sends L1 signaling or L2 signaling to the terminal device, so as to indicate that the terminal device is changed from the H-EDT state to the RRC connected state.

[0252] In a possible implementation, after determining to change the terminal device from the H-EDT state to the RRC connected state, the network device can modify the context information of the terminal device stored on the network device, and record the current RRC state of the terminal device as the RRC connected state.

[0253] Step 803: The network device sends second indication information to the terminal device.

[0254] The second indication information is used to indicate that the terminal device is changed from the H-EDT state to the RRC connected state.

[0255] Optionally, the second indication information is carried in L3 signaling. For example, the L3 signaling can be an RRC connection establishment request message.

[0256] Based on the system architecture shown in FIG. 2, in step 803, the CU (for example, CU-CP) in the RAN sends F1 signaling to the DU, the F1 instruction can include indication information, which can be used to indicate that the H-EDT state is changed, and the DU sends second indication information to the terminal device according to the F1 instruction.

[0257] Based on the system architecture shown in FIG. 3, in step 803, the O-CU (for example, O-CU-CP) in the RAN sends F1 signaling to the O-DU, the F1 instruction can include indication information, which can be used to indicate that the H-EDT state is changed, and the O-DU sends second indication information to the terminal device according to the F1 instruction.

[0258] Step 804: The terminal device enters the RRC connected state according to the second indication information, and the terminal device resumes the measurement on the periodic reference signal in the RRC connected state.

[0259] Optionally, the terminal device can further send RRC state change confirmation information to the network device, to inform the terminal device that the terminal device changes to the RRC connected state.

[0260] In a possible implementation, in the RRC connected state, the terminal device no longer detects the reference signal sent along with the data. In the RRC connected state, the terminal device can resume sending the periodic uplink reference signal to the network device, and the network device can perform channel measurement based on the uplink reference signal. In the RRC connected state, the network device can resume sending the periodic downlink reference signal to the terminal device, and the terminal device can perform channel measurement based on the downlink reference signal.

[0261] In a possible implementation, in the RRC connected state, the terminal device can detect the reference signals of the current cell and the neighboring cells according to the second period, and can perform cell reselection or cell reselection decision based on the reference signals.

[0262] Based on the system architecture shown in FIG. 1, FIG. 2, or FIG. 3, and the RRC state transition diagram shown in FIG. 5 or FIG. 6, FIG. 9 shows a flowchart of a terminal device changing from the H-EDT state to the RRC idle state. In the embodiments of the present application, the functions of the network device can also be performed by a module (such as a chip) in the network device, or by a control subsystem containing the functions of the network device. The control subsystem containing the functions of the network device can be a control center in the above-mentioned application scenarios such as smart grid, industrial control, intelligent transportation, and smart city. The functions of the terminal device can also be performed by a module (such as a chip or a modem) in the terminal device, or by a device containing the functions of the terminal device.

[0263] As shown in FIG. 9, the flowchart can include the following steps:

[0264] Step 901: The network device determines to change the RRC state of the terminal device from the H-EDT state to the RRC idle state.

[0265] Optionally, when the network device determines that the terminal device has no data transmission for a long time, the network device can decide to change the terminal device from the H-EDT state to the RRC idle state, to save power consumption.

[0266] Step 902: The network device sends third indication information to the terminal device.

[0267] The third indication information is used to indicate the change from the H-EDT state to the RRC idle state.

[0268] Optionally, the network device can delete the context information of the terminal device.

[0269] Optionally, the third indication information is carried in L3 signaling.

[0270] Step 903: The terminal device enters the RRC idle state according to the third indication information.

[0271] In the RRC idle state, the RRC connection between the terminal device and the network device is released. After determining that the terminal device enters the RRC idle state, the network device can delete the context information of the terminal device stored on the network device, and record the current RRC state of the terminal device as the RRC idle state.

[0272] Based on the system architecture shown in FIG. 1, FIG. 2 or FIG. 3, and the RRC state transition diagram shown in FIG. 5 or FIG. 6, FIG. 10 shows a flowchart of a terminal device changing from an H-EDT state to an RRC inactive state. In the embodiments of the present application, the functions of the network device can also be performed by a module (such as a chip) in the network device, or by a control subsystem containing the functions of the network device. The control subsystem containing the functions of the network device herein can be a control center in the above-mentioned application scenarios such as smart grid, industrial control, intelligent transportation, and smart city. The functions of the terminal device can also be performed by a module (such as a chip or a modem) in the terminal device, or by a device containing the functions of the terminal device.

[0273] As shown in FIG. 10, the flowchart can include the following steps:

[0274] Step 1001: The network device determines to change the RRC state of the terminal device from the H-EDT state to the RRC inactive state.

[0275] Optionally, when the network device determines that the terminal device has no data transmission for a long time, or the data transmission meets the SDT restriction condition, the network device can decide to change the terminal device from the H-EDT state to the RRC inactive state, so as to save power consumption.

[0276] For example, when one or more of the following conditions are met, the network device can determine to change the terminal device from the H-EDT state to the RRC connected state:

[0277] The service data volume of the downlink service corresponding to the terminal device meets the data volume limit condition of the SDT, for example, the data volume is less than or equal to a threshold sdt-DataVolumeThreshold;

[0278] The change trend of the service data volume is a downward trend;

[0279] The duration of the service meets the transmission duration limit condition of the SDT, for example, the transmission duration is less than or equal to a transmission duration threshold t319.

[0280] Step 1002: The network device sends fourth indication information to the terminal device.

[0281] The fourth indication information is used to indicate a change from the H-EDT state to the RRC inactive state.

[0282] Optionally, the fourth indication information is carried in L1 signaling, L2 signaling, or L3 signaling.

[0283] In step 1003, the terminal device enters the RRC inactive state according to the fourth indication information, and stops measurement on the aperiodic reference signal in the RRC inactive state.

[0284] In the RRC inactive state, the network device retains the context information of the terminal device, and can record the current RRC state of the terminal device as the RRC inactive state.

[0285] Based on the system architecture shown in FIG. 1, FIG. 2, or FIG. 3, and the RRC state transition schematic diagram shown in FIG. 5 or FIG. 6, FIG. 11 shows a flowchart of a terminal device changing from the RRC inactive state to the H-EDT state. In the embodiments of the present application, the functions of the network device can also be performed by a module (such as a chip) in the network device, or by a control subsystem containing the functions of the network device. The control subsystem containing the functions of the network device can be a control center in the above-mentioned application scenarios such as smart grid, industrial control, intelligent transportation, and smart city. The functions of the terminal device can also be performed by a module (such as a chip or a modem) in the terminal device, or by a device containing the functions of the terminal device.

[0286] As shown in FIG. 11, the flowchart can include the following steps:

[0287] In step 1101, the network device sends fifth indication information to the terminal device.

[0288] The fifth indication information is used to indicate a change from the RRC inactive state to the H-EDT state.

[0289] Optionally, the fifth indication information is carried in L1 signaling, L2 signaling, or L3 signaling.

[0290] In one possible implementation, when the network device determines that the terminal device has no data transmission for a long time, or the data transmission no longer meets the SDT restriction condition, the network device can decide to change the terminal device from the RRC inactive state to the H-EDT state, so as to save power consumption.

[0291] For example, when one or more of the following conditions are met, the network device can determine to change the terminal device from the H-EDT state to the RRC connected state:

[0292] The service data volume of the downlink service corresponding to the terminal device does not satisfy the data volume limit condition of the SDT, for example, the data volume is greater than a threshold sdt-DataVolumeThreshold;

[0293] The change trend of the service data volume is an upward trend.

[0294] The duration of the service does not satisfy the transmission duration limit condition of the SDT, for example, the transmission duration is greater than a transmission duration threshold t319.

[0295] Step 1102: The terminal device enters the H-EDT state according to the fifth indication information, and in the H-EDT state, the terminal device starts measurement on the aperiodically transmitted reference signal.

[0296] Based on the flow shown in FIG. 11, in a possible implementation manner, the network device can determine to change the terminal device from the RRC inactive state to the H-EDT state. In this case, the network device can change the terminal device from the RRC inactive state to the H-EDT state by paging the terminal device or sending an activation instruction or a wake-up instruction to the terminal device, and the flow can refer to FIG. 12.

[0297] As shown in FIG. 12, the flow can include the following steps.

[0298] Step 1201: The network device determines to change the terminal device from the RRC inactive state to the H-EDT state.

[0299] Optionally, when the network device determines that there is a downlink transmission demand for the terminal device and the terminal device in the RRC inactive state cannot satisfy the current downlink transmission demand based on the SDT transmission manner, the network device can determine to change the terminal device from the RRC inactive state to the H-EDT state.

[0300] For example, after receiving the downlink data corresponding to the terminal device, the network device determines that the current downlink transmission demand cannot be satisfied based on the SDT transmission manner according to the QoS level of the downlink data, and thus determines to change the terminal device from the RRC inactive state to the H-EDT state.

[0301] Step 1202: The network device sends a first message and a first reference signal sent along with the first message, and the first message includes the fifth indication information.

[0302] Optionally, the first message can be a paging message, or an activation message, or a wake-up message, which is not limited in the present application.

[0303] Optionally, the first reference signal can be a TRS, or other types of reference signals, which are not limited in the present application.

[0304] With the first message being a paging message and the first reference signal being a TRS as an example, in one possible implementation, the location relationship between the paging occasion and the TRS in the time domain is that there is one TRS before one paging occasion, so as to ensure that the terminal device can complete time-frequency synchronization based on the TRS before the paging occasion, and ensure that the terminal device can receive the paging message at the subsequent paging occasion. Specifically, there is at least one TRS in a first time window before the paging occasion, and the time interval between the paging occasion and the first time window can be one or two slots. The terminal device can determine the location of the TRS according to the location of the paging occasion, so as to receive the TRS and perform time-frequency synchronization based on the TRS.

[0305] Step 1203: The terminal device performs time-frequency synchronization according to the first reference signal.

[0306] Step 1204: The terminal device initiates a network access procedure according to the first message, starts measurement on the aperiodically transmitted reference signal (such as the reference signal transmitted along with the data), and enters the H-EDT state.

[0307] In one possible implementation, the first reference signal transmitted along with the data can also be used for channel measurement. The terminal device can perform channel measurement according to the first reference signal, obtain a channel measurement result, and send the channel measurement result to the network device.

[0308] Optionally, the terminal device can send the channel measurement result to the network device through an uplink message in a network access procedure (such as a random access procedure) initiated by the terminal device. For example, the terminal device initiates a random access procedure according to the first message, carries the channel measurement result in a Msg3 message in the random access procedure, and thus sends the channel measurement result to the network device.

[0309] In one possible implementation, the terminal device can also send a second reference signal, and the network device can perform channel measurement based on the second reference signal. The channel measurement result can be used for selecting resources for subsequent transmission of downlink data. Optionally, Msg1 (preamble) in the random access procedure can be used as the second reference signal. The second reference signal can be used for both requesting network access and channel measurement. The network device can allocate resources to the terminal device according to the second reference signal, for subsequent data transmission.

[0310] Based on the flow shown in FIG. 11, in one possible implementation, the terminal device can determine to change the terminal device from the RRC inactive state to the H-EDT state. The flow can refer to FIG. 13.

[0311] As shown in FIG. 13, the flow can include the following steps:

[0312] Step 1301: The terminal device determines to change from the RRC inactive state to the H-EDT state.

[0313] Optionally, the terminal device can determine to change from the RRC inactive state to the H-EDT state according to the obtained service information. The content contained in the service information and the obtaining manner of the service information can refer to the related content in the flowchart shown in FIG. 7.

[0314] Optionally, if the data volume and / or the duration of the service do not meet the restriction condition of the SDT transmission in the RRC inactive state, it can be determined to change from the RRC inactive state to the H-EDT state.

[0315] Step 1302: The terminal device sends a second message to the network device, where the second message is used to request to change from the RRC inactive state to the H-EDT state.

[0316] Optionally, the second message can be L1 signaling or L2 signaling.

[0317] Step 1303: The network device sends a third message to the terminal device, where the third message includes fifth indication information.

[0318] Optionally, the third message can be L1 signaling or L2 signaling.

[0319] Step 1304: The terminal device enters the H-EDT state according to the fifth indication information, and in the H-EDT state, the terminal device starts to measure the non-periodic transmitted reference signal.

[0320] In a possible implementation, before the terminal device sends the second message to the network device, the terminal device can first perform beam alignment by sending an L1 message, and the network device can feed back time-frequency resource scheduling information to the terminal device in response to the L1 message.

[0321] It can be understood that the second message can be a request message, and the third message can be a response message corresponding to the request message, and the message name and the message type are not limited in the present application.

[0322] In a possible implementation, the network device can indicate the terminal device to change from the RRC inactive state to the H-EDT state in an implicit manner, and the flowchart can refer to FIG. 14.

[0323] As shown in FIG. 14, the flowchart can include the following steps.

[0324] Step 1401: The network device sends sixth indication information to the terminal device, where the sixth indication information is used to indicate to receive data on a first time-frequency resource.

[0325] The first time-frequency resource is a resource configured for a terminal device in an H-EDT state for data transmission. Optionally, the first time-frequency resource can be preconfigured or configured by the network device to the terminal device. By indicating the first time-frequency resource to the terminal device, the terminal device can be implicitly instructed to change to the H-EDT state.

[0326] Optionally, the sixth indication information can be carried in L1 signaling or L2 signaling. For example, it can be carried in group downlink control information (group DCI).

[0327] Optionally, the network device can send omnidirectional L1 signaling, so that the terminal device feeds back the optimal beam, thereby realizing beam alignment between the terminal device and the network device.

[0328] Step 1402: The terminal device enters the H-EDT state according to the sixth indication information. In the H-EDT state, the terminal device starts to measure the aperiodic reference signal and receives data on the first time-frequency resource.

[0329] Optionally, the terminal device can determine whether the current RRC state matches the H-EDT state corresponding to the first time-frequency resource. If not, the terminal device changes from the current RRC state to the H-EDT state.

[0330] Optionally, the transmission of subsequent data can also be based on the method shown in the flow.

[0331] In a possible implementation, the terminal device is limited to change to the H-EDT state in the current cell. For example, when the terminal device changes to the RRC inactive state, the network device sends a message for triggering the terminal device to change to the RRC inactive state, which indicates that the terminal device remains in the H-EDT state in the current cell, and instructs the terminal device to monitor L1 signaling according to a given common search space (CSS) configuration or a terminal device-specific search space (UE-specific Search Space, USS) configuration.

[0332] It can be understood that the RRC state conversion flows shown in FIGS. 7 to 14 can be combined with each other. For example, the terminal device can change from the RRC connected state to the H-EDT state based on the flow shown in FIG. 7, and then change from the H-EDT state to the RRC connected state based on the flow shown in FIG. 8. For another example, the terminal device can change from the H-EDT state to the RRC inactive state based on the flow shown in FIG. 10, and then change from the RRC inactive state to the H-EDT state based on the flows shown in FIGS. 12, 13 or 14.

[0333] It should be understood that, in order to realize the functions in the above embodiments, the network device and the terminal device comprise hardware structures and / or software modules corresponding to the functions. Those skilled in the art should easily understand that, in combination with the units and method steps of the examples described in the embodiments disclosed in the present application, the present application can be realized in the form of hardware or a combination of hardware and computer software. Whether a certain function is realized in the form of hardware or computer software driving hardware depends on the specific application scenarios and design constraints of the technical solutions.

[0334] FIG. 15 and FIG. 16 are structural schematic diagrams of possible communication apparatuses provided by the embodiments of the present application. The communication apparatuses can be used to realize the functions of the terminal device or the network device in the above method embodiments, and thus can also realize the beneficial effects possessed by the above method embodiments. In the embodiments of the present application, the communication apparatus can be one of the terminal devices 120a-120j shown in FIG. 1, can be the base station 110a or 110b shown in FIG. 1, or can be a module (such as a chip) applied to a terminal device or a base station.

[0335] As shown in FIG. 15, the communication apparatus 1500 comprises a processing unit 1510 and a transceiver unit 1520. The communication apparatus 1500 is used to realize the functions of the terminal device or the network device in the above method embodiments shown in FIG. 3.

[0336] When the communication apparatus 1500 is used to realize the functions of the terminal device in the method embodiments shown in FIG. 7, the transceiver unit 1520 is used to receive first indication information, the first indication information being used to indicate that the terminal device changes from an RRC connected state to a first state; and the processing unit 1510 is used to cause the terminal device to enter the first state according to the first indication information, in the first state, the terminal device releases an RRC connection between the terminal device and a network device, and starts measurement on aperiodically transmitted reference signals.

[0337] When the communication apparatus 1500 is used to realize the functions of the network device in the method embodiments shown in FIG. 7, the processing unit 1510 is used to send, through the transceiver unit 1520, first indication information, the first indication information being used to indicate that a terminal device changes from an RRC connected state to a first state, in the first state, the terminal device releases an RRC connection between the terminal device and a network device, and starts measurement on aperiodically transmitted reference signals; and the processing unit 1510 releases the RRC connection between the network device and the terminal device.

[0338] When the communication apparatus 1500 is configured to implement the function of the terminal device in the method embodiment shown in FIG. 8: in the first state, the transceiver 1520 is configured to receive second indication information, the second indication information being used to indicate that the terminal device changes from the first state to an RRC connected state; the processing unit 1510 is configured to enter the RRC connected state according to the second indication information, in the RRC connected state, the terminal device resumes the RRC connection between the terminal device and the network device, and stops the measurement of the non-periodically transmitted reference signal.

[0339] When the communication apparatus 1500 is configured to implement the function of the network device in the method embodiment shown in FIG. 8: the processing unit 1510 is configured to send, by the transceiver 1520, second indication information, the second indication information being used to indicate that the terminal device changes from the first state to an RRC connected state; and the RRC connection between the network device and the terminal device is resumed.

[0340] When the communication apparatus 1500 is configured to implement the function of the terminal device in the method embodiment shown in FIG. 11: in the RRC inactive state, the transceiver 1520 is configured to receive fifth indication information, the fifth indication information being used to indicate that the terminal device changes from the RRC inactive state to the first state; and the processing unit 1510 is configured to enter the first state according to the fifth indication information, in the first state, the terminal device resumes the measurement of the non-periodically transmitted reference signal.

[0341] When the communication apparatus 1500 is configured to implement the function of the network device in the method embodiment shown in FIG. 11: the processing unit 1510 is configured to send, by the transceiver 1520, fifth indication information, the fifth indication information being used to indicate that the terminal device changes from the RRC inactive state to the first state. In the first state, the terminal device releases the RRC connection between the terminal device and the network device, and starts the measurement of the non-periodically transmitted reference signal.

[0342] When the communication apparatus 1500 is configured to implement the function of the terminal device in the method embodiment shown in FIG. 14: in the RRC inactive state, the transceiver 1520 receives sixth indication information, the sixth indication information being used to indicate that the terminal device receives data on a first time-frequency resource; the first time-frequency resource is a resource configured for the terminal device in the first state to use for data transmission; and the processing unit 1510 is configured to enter the first state according to the sixth indication information, in the first state, the terminal device resumes the measurement of the non-periodically transmitted reference signal, and receives data on the first time-frequency resource.

[0343] When the communication apparatus 1500 is configured to implement the function of the network device in the method embodiment shown in FIG. 14, the processing unit 1510 is configured to send, through the transceiver unit 1520, sixth indication information, the sixth indication information being used to instruct the terminal device to receive data on the first time-frequency resource; wherein the first time-frequency resource is a resource configured for the terminal device in the first state to use for data transmission.

[0344] More detailed description of the processing unit 1510 and the transceiver unit 1520 can be directly obtained by referring to the related description in the method embodiment shown in any one of FIGS. 7 to 14, which will not be repeated here.

[0345] As shown in FIG. 16, the communication apparatus 1600 includes a processor 1610 and an interface circuit 1620. The processor 1610 and the interface circuit 1620 are coupled to each other. It can be understood that the interface circuit 1620 can be a transceiver or an input / output interface. Optionally, the communication apparatus 1600 can further include a memory 1630, used to store instructions executed by the processor 1610 or to store input data required by the processor 1610 to run instructions or to store data generated after the processor 1610 runs instructions.

[0346] When the communication apparatus 1600 is configured to implement the method shown in any one of FIGS. 7 to 14, the processor 1610 is configured to implement the function of the processing unit 1510 described above, and the interface circuit 1620 is configured to implement the function of the transceiver unit 1520 described above.

[0347] When the above communication apparatus is a chip applied to a terminal device, the terminal chip implements the function of the terminal device in the above method embodiment. The terminal chip receives information from other modules (such as a radio frequency module or an antenna) in the terminal device, and the information is sent by the network device to the terminal device; or the terminal chip sends information to other modules (such as a radio frequency module or an antenna) in the terminal device, and the information is sent by the terminal device to the network device.

[0348] When the above communication apparatus is a module applied to a network device, the network device module implements the function of the network device in the above method embodiment. The network device module receives information from other modules (such as a radio frequency module or an antenna) in the network device, and the information is sent by the terminal device to the network device; or the network device module sends information to other modules (such as a radio frequency module or an antenna) in the network device, and the information is sent by the network device to the terminal device. The network device module here can be a baseband chip of the network device, or a DU or other module, and the DU here can be a DU under the open radio access network (O-RAN) architecture.

[0349] It can be understood that the processor in the embodiments of the present application can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor can be a microprocessor, or any conventional processor.

[0350] In the present application, another example of a communication apparatus is provided, which comprises at least one processor and at least one memory, the at least one processor and the at least one memory are coupled, the at least one memory is configured to store instructions, when the instructions are executed by the at least one processor, the communication apparatus performs the method in the above embodiments. Taking the communication apparatus comprising one processor and one memory as an example, as shown in FIG. 16, the communication apparatus 1600 comprises one processor 1610 and one memory 1630. The processor 1610 and the memory 1630 are coupled, and the memory 1630 stores instructions, when the instructions stored in the memory 1630 are executed by the processor 1610, the communication apparatus 1600 performs the method performed by the terminal device or the network device in the above embodiments.

[0351] The method steps in the embodiments of the present application can be implemented in hardware, or can be implemented in software instructions executable by a processor. The software instructions can be composed of corresponding software modules, and the software modules can be stored in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically programmable read-only memory, a register, a hard disk, a mobile hard disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor, so that the processor can read information from the storage medium, and can write information to the storage medium. The storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in the network device or the terminal device. The processor and the storage medium can also exist as discrete components in the network device or the terminal device.

[0352] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer programs or instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments are performed. The computer can be a general purpose computer, a special purpose computer, a computer network, a network device, a user equipment or other programmable apparatus. The computer programs or instructions can be stored in a computer readable storage medium or transferred from one computer readable storage medium to another computer readable storage medium, for example, the computer programs or instructions can be transferred from one website site, computer, server or data center to another website site, computer, server or data center through wired or wireless manner. The computer readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center and the like integrated with one or more available media. The available media can be a magnetic medium, such as a floppy disk, a hard disk, a magnetic tape; or an optical medium, such as a digital video disc; or a semiconductor medium, such as a solid state disk. The computer readable storage medium can be a volatile or non-volatile storage medium, or can include both volatile and non-volatile storage media.

[0353] In various embodiments of the present application, the terms and / or descriptions of different embodiments are consistent and can be referred to each other if there is no special description and logical conflict, and the technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0354] In the present application, "at least one" means one or more, and "multiple" means two or more. The "and / or" describes the association relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B, which can represent the following cases: A exists alone, A and B exist together, B exists alone, where A and B can be singular or plural. In the literal description of the present application, the character " / ", generally represents that the associated objects before and after are in an "or" relationship; in the formula of the present application, the character " / ", represents that the associated objects before and after are in a "division" relationship. "Including at least one of A, B and C" can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B and C.

[0355] It can be understood that various numbers involved in the embodiments of the present application are only distinguished for convenience of description, and are not used to limit the scope of the embodiments of the present application. The size of the serial number of the above processes does not mean the order of execution, and the execution order of the processes should be determined according to their functions and inherent logic.

Claims

1. A communication method characterized by comprising: Applied to a terminal device, comprising: receiving first indication information, the first indication information is used to indicate that the terminal device changes from a radio resource control (RRC) connected state to a first state; entering the first state according to the first indication information, in the first state, the RRC connection between the terminal device and the network device is released, and the measurement of the non-periodic transmitted reference signal is started.

2. The method of claim 1, wherein, Before the first indication information is received, further comprising: sending service information, the service information is used to make a decision on RRC state change.

3. The method of claim 2, wherein, The service information includes one or more of the following: service data volume, service data volume trend, service duration and service type.

4. The method of claim 1, wherein, Before the first indication information is received, further comprising: sending state change tendency information, the state change tendency information indicates the first state.

5. The method according to any one of claims 1 to 4, characterized in that, In the first state, the terminal device further comprises: receiving second indication information, the second indication information is used to indicate that the terminal device changes from the first state to the RRC connected state; entering the RRC connected state according to the second indication information, in the RRC connected state, the RRC connection between the terminal device and the network device is restored, and the measurement of the non-periodic transmitted reference signal is stopped.

6. The method of claim 5, wherein, Before the second indication information is received, further comprising: sending service information and / or state change tendency information, the service information is used to make a decision on RRC state change, and the state change tendency information indicates the RRC connected state.

7. The method according to any one of claims 1 to 6, wherein In the first state, the terminal device further comprises: receiving fourth indication information, the fourth indication information is used to indicate that the terminal device changes from the first state to the RRC inactive state; entering the RRC inactive state according to the fourth indication information, in the RRC inactive state, the measurement of the non-periodic transmitted reference signal is stopped.

8. The method of claim 7, wherein, In the RRC inactive state, the terminal device further comprises: receiving fifth indication information, the fifth indication information is used to indicate that the terminal device changes from the RRC inactive state to the first state; entering the first state according to the fifth indication information, in the first state, the measurement of the non-periodic transmitted reference signal is restored.

9. The method of claim 8, wherein, The fifth indication information is received, comprising: receiving a first message and a first reference signal sent with the first message, the fifth indication information is included in the first message; performing time-frequency synchronization according to the first reference signal; initiating a network access procedure according to the first message, and changing from the RRC inactive state to the first state.

10. The method of claim 9, wherein, Further comprising: performing channel measurement according to the first reference signal to obtain channel measurement results; sending the channel measurement results based on the uplink message in the network access procedure.

11. The method according to any one of claims 9-10, wherein, The network access procedure is initiated according to the first message, comprising: sending a second reference signal according to the first message, the second reference signal is used to request network access and is used for channel measurement.

12. The method of claim 8, wherein, The fifth indication information is received, comprising: determining to change from the RRC inactive state to the first state; sending a second message, the second message being used for requesting to change from the RRC inactive state to the first state; receiving a third message corresponding to the second message, the third message comprising the fifth indication information.

13. The method of claim 7, wherein, The terminal device in the RRC inactive state further comprises: receiving sixth indication information, the sixth indication information being used for indicating the terminal device to receive data on a first time-frequency resource; wherein the first time-frequency resource is a resource configured for terminal devices in the first state to perform data transmission; entering the first state according to the sixth indication information, the terminal device in the first state resuming measurement on aperiodically transmitted reference signals and receiving data on the first time-frequency resource.

14. A communication method characterized by comprising: application to a network device, comprising: sending first indication information, the first indication information being used for indicating a terminal device to change from a radio resource control (RRC) connected state to a first state, the terminal device in the first state releasing an RRC connection with the network device and starting measurement on aperiodically transmitted reference signals; releasing the RRC connection between the network device and the terminal device.

15. The method of claim 14, wherein, Before the sending of the first indication information, further comprising: receiving service information corresponding to the terminal device; determining to change the terminal device from the RRC connected state to the first state according to the service information.

16. The method of claim 14, wherein, Before the sending of the first indication information, further comprising: receiving state change tendency information of the terminal device, the state change tendency information indicating the first state; determining to change the terminal device from the RRC connected state to the first state according to the state change tendency information.

17. The method of any one of claims 14-16, wherein, further comprising: stopping sending periodic reference signals to the terminal device; and / or stopping measurement on the periodic reference signals transmitted to the terminal device.

18. The method of any one of claims 14-17, wherein, After the sending of the first indication information, further comprising: sending second indication information, the second indication information being used for indicating the terminal device to change from the first state to the RRC connected state; resuming the RRC connection with the terminal device.

19. The method of claim 18, wherein, further comprising: receiving service information corresponding to the terminal device; determining to change the terminal device from the first state to the RRC connected state according to the service information.

20. The method of claim 18, wherein, further comprising: receiving state change tendency information of the terminal device, the state change tendency information indicating the RRC connected state; determining to change the terminal device from the first state to the RRC connected state according to the state change tendency information.

21. The method of any one of claims 18-20, wherein, further comprising: resuming sending periodic reference signals to the terminal device; and / or resuming measurement on the periodic reference signals transmitted to the terminal device.

22. The method of any one of claims 14-17, wherein, After the sending of the first indication information, further comprising: sending fourth indication information, the fourth indication information being used for indicating the terminal device to change from the first state to the RRC inactive state.

23. The method of claim 22, wherein, After the sending of the fourth indication information, further comprising: sending fifth indication information, the fifth indication information being used for indicating the terminal device to change from the RRC inactive state to the first state.

24. The method of claim 23, wherein, the sending of the fifth indication information comprises: transmitting a first message and a first reference signal sent along with the first message, the first message comprising the fifth indication information, and the first reference signal being used for time-frequency synchronization.

25. The method of claim 24, wherein, Further comprising: receiving an uplink message in a network access procedure initiated by the terminal device based on the first message, the uplink message comprising channel measurement results, the channel measurement results being obtained based on the first reference signal.

26. The method of claim 24, wherein, Further comprising: receiving an uplink message and a second reference signal in a network access procedure initiated by the terminal device based on the first message, the second reference signal being used for requesting network access and for channel measurement.

27. The method of claim 23, wherein, The transmitting of the fifth indication information comprises: receiving a second message, the second message being used for requesting a change from an RRC inactive state to the first state; in response to the second message, transmitting a third message, the third message comprising the fifth indication information.

28. The method of claim 22, wherein, Further comprising, after the transmitting of the fourth indication information: transmitting sixth indication information, the sixth indication information being used for indicating that data is received on a first time-frequency resource, wherein the first time-frequency resource is a resource configured for terminal devices in the first state to use for data transmission.

29. A communications device, characterized by Comprising: one or more processors configured to perform the method of any one of claims 1-13, or perform the method of any one of claims 14-28.

30. A readable storage medium, characterized by, The readable storage medium stores a program or instruction, when the program or instruction is run on the apparatus, causing the apparatus to perform the method of any one of claims 1-13, or perform the method of any one of claims 14-28.

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