Communication method and apparatus

Abstract

A communication method and 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 an RRC connected 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, the terminal device maintains an RRC connection between the terminal device and a network device, and stops measuring a periodic reference signal.

Description

A communication method and apparatus

[0001] Cross-reference to Related Applications

[0002] This application claims priority to the Chinese Patent Application No. 202411247932.6, 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 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, the terminal device maintaining an RRC connection with a network device and stopping measurement on a periodic reference signal in the first state.

[0013] In the above implementation, since the terminal device maintains the RRC connection with the network device in the first state, data transmission can be implemented. Since the terminal device stops measurement on the periodic reference signal in the first state, the power consumption of the terminal device can be reduced compared with the RRC connected state, and energy saving can be achieved.

[0014] In a possible implementation, the first indication information is carried in L1 signaling or L2 signaling.

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

[0016] In a possible implementation, the service information comprises 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.

[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 state change tendency 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 service duration is less than or equal to a duration threshold.

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

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

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

[0023] In a possible implementation manner, 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 manner, in the first state, the method further includes: receiving downlink data and a reference signal sent along with the downlink data; performing measurement on the reference signal to obtain a measurement result; and sending the measurement result.

[0025] In the foregoing implementation manner, in the first state, the terminal device can perform channel measurement and reporting based on the reference signal sent along, so as to select resources 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 the periodical reference signal, thereby saving the power consumption of the terminal device.

[0026] In a possible implementation manner, in the first state, the method further includes: receiving 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 entering the RRC connected state according to the second indication information, and the terminal device resumes measurement on the periodical reference signal in the RRC connected state.

[0027] Optionally, the second indication information is carried in L1 signaling or L2 signaling.

[0028] In a possible implementation manner, before the receiving of the second indication information, the method further includes: sending service information and / or state change tendency information, the state change tendency information indicating the RRC connected state.

[0029] In a possible implementation manner, in the first state, the method further includes: receiving third indication information, the third indication information being 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, and the RRC connection between the terminal device and the network device is released in the RRC idle state.

[0030] In a possible implementation, in the first state, the method 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, in the RRC inactive state, the RRC connection between the terminal device and the network device is released.

[0031] 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 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 the RRC connected state according to the second indication information, in the RRC connected state, the terminal device resumes measurement on a periodic reference signal. In the first state, the RRC connection between the terminal device and the network device is maintained, and the measurement on the periodic reference signal is stopped.

[0032] Optionally, the second indication information is carried in L1 signaling or L2 signaling.

[0033] Optionally, before the receiving the second indication information, the method further includes: sending service information and / or state change tendency information, the state change tendency information indicating the RRC connected state.

[0034] In a third aspect, a communication method is provided, which can be applied to a terminal device. The method includes: in a first state, 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, in the RRC inactive state, the RRC connection between the terminal device and the network device is released. In the first state, the RRC connection between the terminal device and the network device is maintained, and the measurement on a periodic reference signal is stopped.

[0035] In a fourth aspect, a communication method is provided, which can be applied to a network device. The method includes: maintaining an RRC connection between the network device and a terminal device; and sending 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; in the first state, the terminal device maintains the RRC connection with the network device, and stops measurement on a periodic reference signal.

[0036] In a possible implementation, before the sending the first indication information, the method further includes: receiving service information corresponding to the terminal device; and determining, according to the service information, that the terminal device changes from the RRC connected state to the first state. In a possible implementation, before the sending the first indication information, the method further includes: receiving service information corresponding to the terminal device; and determining, according to the service information, that the terminal device changes from the RRC connected state to the first state.

[0037] In a possible implementation manner, the service information comprises one or more of the following: a service data volume, a service data volume change trend, a service duration, and a service type.

[0038] In a possible implementation manner, before the first indication information is sent, the method further comprises: receiving state change tendency information of the terminal device, the state change tendency information indicating the first state; and determining, according to the state change tendency information, that the terminal device is to be changed from the RRC connected state to the first state.

[0039] In a possible implementation manner, the state change tendency information comprises first duration information, the first duration information being used to indicate a duration of the first state; and the method further comprises: determining, according to the first duration information, a length of time during which the terminal device is in the first state.

[0040] In a possible implementation manner, the method further comprises: stopping sending periodic reference signals to the terminal device; and / or, stopping measuring the periodic reference signals sent by the terminal device.

[0041] In a possible implementation manner, after the first indication information is sent, the method further comprises: sending second indication information, the second indication information being used to indicate that the terminal device is to be changed from the first state to the RRC connected state.

[0042] In a possible implementation manner, the method further comprises: receiving service information from the terminal device; and determining, according to the service information, that the terminal device is to be changed from the first state to the RRC connected state.

[0043] In a possible implementation manner, the method further comprises: receiving state change tendency information from the terminal device, the state change tendency information indicating the RRC connected state; and determining, according to the state change tendency information, that the terminal device is to be changed from the first state to the RRC connected state.

[0044] In a possible implementation manner, the method further comprises: resuming sending periodic reference signals to the terminal device; and / or, resuming measuring the periodic reference signals sent by the terminal device.

[0045] In a possible implementation manner, after the first indication information is sent, the method further comprises: sending third indication information, the third indication information being used to indicate that the terminal device is to be changed from the first state to the RRC idle state; and releasing an RRC connection between the network device and the terminal device.

[0046] 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; releasing an RRC connection between the network device and the terminal device, and reserving context information of the terminal device.

[0047] In a fifth aspect, a communication method is provided, which can be applied to a network device. The method includes: when a terminal device is in a first state, sending second indication information to the terminal device, the second indication information being used to indicate that the terminal device changes from the first state to an RRC connected state. In the first state, an RRC connection between the terminal device and the network device is maintained, and measurement on a periodic reference signal is stopped.

[0048] Optionally, the method further includes: receiving service information from the terminal device; and determining, according to the service information, that the terminal device changes from the first state to the RRC connected state.

[0049] Optionally, the method further includes: receiving state change tendency information from the terminal device, the state change tendency information indicating the RRC connected state; and determining, according to the state change tendency information, that the terminal device changes from the first state to the RRC connected state.

[0050] Optionally, the method further includes: resuming sending of the periodic reference signal to the terminal device; and / or resuming measurement on the periodic reference signal sent by the terminal device.

[0051] In a sixth aspect, a communication method is provided, which can be applied to a network device. The method includes: when a terminal device is in a first state, sending fourth indication information to the terminal device, the fourth indication information being used to indicate that the terminal device changes from the first state to an RRC inactive state; and releasing an RRC connection between the network device and the terminal device, and reserving context information of the terminal device. In the first state, an RRC connection between the terminal device and the network device is maintained, and measurement on a periodic reference signal is stopped.

[0052] In a seventh aspect, a communication method is provided, which can be applied to a terminal device. The method includes: starting a first timer at a first time point in an RRC connected state; and when the first timer expires, entering a first state, in which the terminal device maintains an RRC connection between the terminal device and a network device, and stops measurement on a periodic reference signal.

[0053] In a possible implementation, the method further includes: during running of the first timer, if the service data volume is less than or equal to the data volume threshold or the service data volume change trend is a downward trend, restarting the first timer at a second time point during running of the first timer; and sending a notification message, the notification message being used to notify the network device to restart the first timer running on the network device at the second time point.

[0054] In a possible implementation, the method further includes: during running of the first timer, receiving a notification message, the notification message being used to notify the terminal device to restart the first timer at a second time point during running of the first timer; and according to the notification message, restarting the first timer running on the terminal device at the second time point.

[0055] In a possible implementation, after the terminal device enters the first state, the method further includes: starting a second timer at a third time point; and when the second timer times out, entering an RRC connected state, and resuming measurement of the periodic reference signal in the RRC connected state.

[0056] In a possible implementation, the method further includes: during running of the second timer, if the service data volume is greater than the data volume threshold or the service data volume change trend is an upward trend, restarting the second timer at a fourth time point during running of the second timer; and sending a notification message, the notification message being used to notify the network device to restart the second timer running on the network device at the fourth time point.

[0057] In a possible implementation, the method further includes: during running of the second timer, receiving a notification message, the notification message being used to notify the terminal device to restart the first timer at a fourth time point during running of the second timer; and according to the notification message, restarting the first timer running on the terminal device at the fourth time point.

[0058] In an eighth aspect, a communication method is provided, which can be applied to a network device. The method includes: starting a first timer at a first time point when a terminal device is in an RRC connected state; and when the first timer times out, changing the terminal device from the RRC connected state to a first state, in which the network device maintains RRC connection with the terminal device; and wherein the terminal device in the first state stops measurement of a periodic reference signal.

[0059] In a possible implementation, the method further includes: receiving a notification message during running of the first timer, the notification message being used to notify the network device to restart the first timer at a second time during running of the first timer; and restarting the first timer at the second time according to the notification message.

[0060] In a possible implementation, the method further includes: restarting the first timer at a second time during running of the first timer, if the service data volume of the service corresponding to the terminal device is less than or equal to a data volume threshold or a service data volume change trend is a downward trend; and sending a notification message, the notification message being used to notify the terminal device to restart the first timer running on the terminal device at the second time.

[0061] In a possible implementation, after the terminal device is changed from the RRC connected mode to the first state, the method further includes: starting a second timer at a third time; and changing the terminal device from the first state to the RRC connected mode when the second timer times out.

[0062] In a possible implementation, the method further includes: resuming sending of the periodic reference signal to the terminal device when the second timer times out.

[0063] In a possible implementation, the method further includes: receiving a notification message during running of the second timer, the notification message being used to notify the network device to restart the second timer at a fourth time during running of the second timer; and restarting the second timer at the fourth time according to the notification message.

[0064] In a possible implementation, the method further includes: restarting the second timer at a fourth time during running of the second timer, if the service data volume of the service corresponding to the terminal is greater than a data volume threshold or a service data volume change trend is an upward trend; and sending a notification message, the notification message being used to notify the terminal device to restart the second timer running on the terminal device at the fourth time.

[0065] In a ninth aspect, a communication method is provided, which can be applied to a terminal device. The method includes: starting a third timer when a data volume meets a first condition in an RRC connected mode; stopping the third timer during running of the third timer, if the data volume does not meet the first condition; and sending a request message when the third timer times out, the request message being used to request to change to a first state; wherein the terminal device in the first state maintains an RRC connection with a network device and stops measurement of a periodic reference signal.

[0066] In a possible implementation, after the sending the request message, the method further includes: receiving indication information, the indication information being used to indicate that the terminal device changes from the RRC connected state to the first state; and entering the first state according to the indication information.

[0067] In a possible implementation, the data amount of the transmission satisfies a first condition, including one or more of the following: the data amount is less than or equal to a threshold value; and a change trend of the data amount is a decrease.

[0068] In a tenth aspect, a communication apparatus is provided, including units or modules configured to perform the method in any one of the first aspect to the ninth aspect.

[0069] In an eleventh aspect, a communication apparatus is provided, including one or more processors configured to perform the method in any one of the first aspect to the ninth aspect.

[0070] In a twelfth aspect, a readable storage medium is provided, the readable storage medium storing a program or instructions, when the program or instructions are run on an apparatus, causing the apparatus to perform the method in any one of the first aspect to the ninth aspect.

[0071] In a thirteenth aspect, a chip system is provided, including a processor, configured to support a computer apparatus to implement the method in any one of the first aspect to the ninth aspect.

[0072] In a fourteenth aspect, a computer program product is provided, the computer program product including a program; when the computer program is run on a computer, causing the computer to perform the method in any one of the first aspect to the ninth aspect.

[0073] In a fifteenth aspect, a communication system is provided, including a network device and a terminal device, the terminal device performing the method in any one of the first aspect, the network device performing the method in any one of the fourth aspect; or the terminal device performing the method in any one of the second aspect, the network device performing the method in any one of the fifth aspect; or the terminal device performing the method in any one of the third aspect, the network device performing the method in any one of the sixth aspect; or the terminal device performing the method in any one of the seventh aspect, the network device performing the method in any one of the eighth aspect; or the terminal device performing the method in any one of the ninth aspect. BRIEF DESCRIPTION OF DRAWINGS

[0074] FIG. 1 is a schematic diagram of an architecture of a communication system to which embodiments of the present application are applied;

[0075] FIG. 2 is a schematic diagram of a protocol stack of a RAN node according to an embodiment of the present application;

[0076] FIG. 3 is a schematic diagram of an O-RAN structure according to an embodiment of the present application;

[0077] FIG. 4 is a schematic diagram of state transition between RRC connected state, RRC idle state and RRC inactive state according to an embodiment of the present application;

[0078] FIG. 5 is a schematic diagram of state transition between RRC connected state, RRC idle state and H-EDT state according to an embodiment of the present application;

[0079] FIG. 6 is a schematic diagram of state transition between RRC connected state, RRC idle state, RRC inactive state and H-EDT state according to an embodiment of the present application;

[0080] FIG. 7 is a schematic diagram of a process of changing a terminal device from RRC connected state to H-EDT state according to an embodiment of the present application;

[0081] FIG. 8 is a schematic diagram of a process of changing a terminal device from H-EDT state to RRC connected state according to an embodiment of the present application;

[0082] FIG. 9 is a schematic diagram of a process of changing a terminal device from H-EDT state to RRC idle state according to an embodiment of the present application;

[0083] FIG. 10 is a schematic diagram of a process of changing a terminal device from H-EDT state to RRC inactive state according to an embodiment of the present application;

[0084] FIG. 11 is a schematic diagram of another process of changing a terminal device from RRC connected state to H-EDT state according to an embodiment of the present application;

[0085] FIG. 12 is a schematic diagram of another process of changing a terminal device from H-EDT state to RRC connected state according to an embodiment of the present application;

[0086] FIG. 13 is a schematic diagram of another process of changing a terminal device from RRC connected state to H-EDT state according to an embodiment of the present application;

[0087] FIG. 14 is a schematic diagram of a structure of a communication apparatus according to an embodiment of the present application;

[0088] FIG. 15 is a schematic diagram of a structure of another communication apparatus according to an embodiment of the present application. DETAILED DESCRIPTION

[0089] The embodiments of the present application can be applied to various communication systems, for example, 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.

[0090] Referring to FIG. 1, it is a schematic diagram of an architecture of a communication system 1000 to which the embodiments of the present application are 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 (for example, 110a and 110b in FIG. 1) and at least one terminal device (for example, 120a-120j in FIG. 1). The terminal device is connected to the radio access network device in a wireless manner, and the radio access network device is connected to the core network in a wireless or wired manner. The core network device and the radio access network device can be independent and different physical devices, or the functions of the core network device and the logical functions of the radio access network device can be integrated on the same physical device, or a physical device can integrate the functions of part of the core network device and part of the radio access network device. The terminal device and the terminal device, and the radio access network device and the radio access network device can be connected to each other in a wired or wireless manner. FIG. 1 is only a schematic diagram, and the communication system can further include other network devices, for example, a wireless relay device and a wireless backhaul device, which are not shown in FIG. 1.

[0091] The network device and the terminal device can be fixed in position or movable. The network device and the terminal device can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can be deployed on water; and can be deployed on an airplane, a balloon, and a man-made satellite. Embodiments of the present application do not limit the application scenarios of the network device and the terminal device.

[0092] The roles of the network device and the terminal device 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 the terminal device 120j that accesses the wireless 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 communicates with 120i through a wireless air interface protocol. Of course, 110a and 120i can also communicate through an interface protocol between network devices, and in this case, 120i is also a network device relative to 110a. Therefore, the network device and the terminal device can be collectively referred to as a communication apparatus, and 110a and 110b in FIG. 1 can be referred to as a communication apparatus with a network device function, and 120a-120j in FIG. 1 can be referred to as a communication apparatus with a terminal device function.

[0093] The network device and the terminal device, the network device and the network device, and the terminal device and the terminal device can communicate through a licensed spectrum, can communicate through an unlicensed spectrum, and can simultaneously communicate through a licensed spectrum and an unlicensed spectrum; can communicate through a spectrum below 6 gigahertz (GHz), can communicate through a spectrum above 6 GHz, and can simultaneously use a spectrum below 6 GHz and a spectrum above 6 GHz. Embodiments of the present application do not limit the spectrum resources used for wireless communication.

[0094] In 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 a control subsystem containing network device functions. The control subsystem containing network device functions 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 a device containing terminal device functions.

[0095] 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 referred to as a serving cell of the terminal device.

[0096] 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 media 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 used in 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, autonomous driving, remote medical treatment, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc. The embodiments of the present application do not limit the specific technology and specific device form of the terminal device.

[0097] 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 to help 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.

[0098] 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).

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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 part of the functions of the protocol layers are controlled by the CU, and the rest or all of the functions 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.

[0103] 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).

[0104] 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).

[0105] 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 embodiments 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.

[0106] 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.

[0107] Table 1: Correspondence between network elements of O-RAN and protocol layer functions that can be implemented

[0108] 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).

[0109] 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.

[0110] In current communication protocols, 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, a terminal device in an RRC connected state initiates an RRC connection release procedure according to a received RRC connection release message, and switches to an RRC idle state or an RRC inactive state. A terminal device in an RRC idle state or an RRC inactive state switches to an RRC connected state through a random access procedure. For a terminal device in an RRC connected state, if the RRC connection release message contains suspendConfig, the terminal device enters an RRC inactive state after RRC connection release, and if the RRC connection release message does not contain suspendConfig, the terminal device enters an RRC idle state after RRC connection release. The suspendConfig carries the contents of an inactive radio network temporary identity (I-RNTI), RAN-NotificationAreaInfo, a RAN paging cycle, a T380 timer, and the like, and is used for RRC inactive state paging, RAN-based notification area (RNA) updating, and the like.

[0111] In order to ensure data transmission efficiency while obtaining better energy saving effect, 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.

[0112] 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, a terminal device in the first state maintains an RRC connection with a network, can perform data transmission, but stops measuring a periodic reference signal. Compared with the RRC inactive state, the terminal device in the first state can obtain better data transmission efficiency, and compared with the RRC connected state, the terminal device in the first state can obtain better energy saving effect.

[0113] Based on the above description of the first state, in one possible manner, the first state can be regarded as an enhanced RRC connected state, and the first state can achieve better energy saving effect on the basis of the RRC connected state. Optionally, 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 connected state", an "energy-saving RRC connected state", a "CONNECTED 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 the H-EDT state as an example for description below.

[0114] When the terminal device is in the H-EDT state, the RRC connection is maintained between the terminal device and the network device, and the network device stores and maintains the context information of the terminal device. Therefore, 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). Therefore, when there is a data transmission requirement, the terminal device in the H-EDT state can perform data transmission with the network side.

[0115] Optionally, 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. Optionally, 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 terminal device in the current RRC inactive state, only the control plane integrity key K_{RRC,int} is retained.

[0116] In one possible implementation, unlike the terminal device in the RRC inactive state, the data transmission between the terminal device in the H-EDT state and the network side can have no time limit. Optionally, the data transmission between the terminal device in the H-EDT state and the network side can also have no data packet size limit.

[0117] In another possible implementation, the data transmission between the terminal device in the H-EDT state and the network side has a time length limit, that is, the data transmission time length between the terminal device in the H-EDT state and the network side is less than or equal to a transmission time length threshold. Optionally, the transmission time length threshold can be preconfigured or configured by the network side. Optionally, the data transmission between the terminal device in the H-EDT state and the network side has a data volume limit, that is, the data volume of the data transmission between the terminal device in the H-EDT state and the network side is less than or equal to a data volume threshold. Optionally, the data volume threshold can be preconfigured or configured by the network side.

[0118] Unlike the RRC connected state, the terminal device in the H-EDT state does not need to detect the downlink reference signal periodically transmitted by the network side, and optionally, does not need to transmit the periodic uplink reference signal to the network side. For example, the downlink reference signal periodically transmitted by the network side can include a channel state information reference signal (CSI-RS), and more specifically, for example, a CSI-RS with a period of 20 ms; for another example, the periodic uplink reference signal transmitted by the terminal device can include a sounding reference signal (SRS). The type of reference signal is not limited in the present application.

[0119] Since the terminal device in the H-EDT state does not need to monitor the periodic downlink reference signal, it also does not need to perform channel measurement based on the periodic downlink reference signal and report the measurement result to the network side, thereby saving the power consumption of the terminal device. Optionally, for the network device, since the terminal device in the H-EDT state does not need to monitor the periodic downlink reference signal, the network device does not need to transmit the downlink reference signal to the terminal device in the H-EDT state, thereby saving the power consumption of the network device.

[0120] Since the terminal device in the H-EDT state does not need to periodically transmit the uplink reference signal, the power consumption of the terminal device can be saved. Optionally, for the network device, since the terminal device in the H-EDT state does not need to periodically transmit the uplink reference signal, the network device also does not need to perform channel measurement based on the uplink reference signal, thereby saving the power consumption of the network device.

[0121] In a possible implementation, for the terminal device in the H-EDT state, the network device can send a reference signal along with the data, and correspondingly, the terminal device can receive the reference signal sent by the network device along with the data, perform channel measurement based on the reference signal, and the result of the channel measurement can be used to select appropriate resources for subsequent data transmission.

[0122] An example of the network device sending the reference signal along with the data is that the network device sends the reference signal along with the downlink data. For example, the network device can send the downlink data (data carried by PDSCH, including a paging message or data) and the reference signal along with the downlink data. Another example is that the network device sends the reference signal along with the control signaling. Still another example is that the 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 along with the downlink data can be sent on the same channel or different channels, which is not limited in the present application.

[0123] For example, in the case of sending the reference signal along with the downlink data, the network device can send the reference signal to the terminal device in the H-EDT state on a channel along with the data. The channel along with the data and the reference signal shares the same physical channel as the service channel used to transmit the 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 the PDSCH. For example, the network device transmits 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 downlink reference signal sent along with the data can be a CSI-RS.

[0124] For another example, the network device sends the downlink control signaling and the downlink reference signal 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 a certain rule. For example, there is at least one TRS in the 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.

[0125] The present application does not limit the implementation of sending the downlink reference signal 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.

[0126] Since the network device sends downlink data and a reference signal sent along the way to the terminal device in the H-EDT state only when there is a demand for downlink data transmission, and the terminal device measures the reference signal sent along the way accordingly, the terminal device in the H-EDT state can reduce power consumption compared with the terminal device in the RRC connected state that needs to monitor and measure the periodic downlink reference signal.

[0127] 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 can improve data transmission efficiency by measuring the downlink reference signal sent along the way and selecting a suitable bandwidth resource for data transmission with the network side based on channel measurement.

[0128] In a possible implementation, the terminal device in the H-EDT state can receive a reference signal periodically sent by a current cell and a neighboring cell, and can determine whether to perform cell switching according to signal reception strength and the like. For example, the reference signal can be a synchronization signal block (SSB).

[0129] Optionally, compared with the terminal device in the RRC connected state, the terminal device in the H-EDT state can monitor the reference signal of the current cell and the neighboring cell with a longer period, and thus determine whether to perform cell switching according to signal reception strength and the like. Since the terminal device in the H-EDT state monitors and measures the reference signal of the current cell and the neighboring cell with a longer period, the terminal device in the H-EDT state can save power consumption compared with the terminal device in the RRC connected state.

[0130] For example, the measurement period of the terminal device in the H-EDT state for the reference signal of the current cell and the neighboring cell is a first period, and the measurement period of the terminal device in the RRC connected state for the reference signal of the current cell and the neighboring cell is a second period. The length of the first period is greater than the length of the second period.

[0131] In a possible implementation, the length of the first period can be preconfigured or configured by the network side.

[0132] 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, an integer greater than 1, so that the length of the first period is an integer multiple of the length of the second period.

[0133] It should be understood that the "measurement relaxation factor" can also be referred to as a "correction factor" or an "adjustment factor", and the like, and the naming of this parameter in the present application is not limited.

[0134] Optionally, the measurement relaxation factor can be preconfigured or configured to the terminal device by the network side. For example, the network device can send the measurement relaxation factor to the terminal device in a message for instructing 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.

[0135] In a possible implementation, unlike the terminal device in the RRC connected state which supports dual connectivity (DC) and carrier aggregation (CA), the terminal device in the H-EDT state does not support DC and CA. In this way, the complexity of technical implementation can be reduced.

[0136] In a possible implementation, the related parameters of the H-EDT state (for example, including the related parameters of the condition to be met by the terminal device when entering the H-EDT state, and / or the related parameters of the restriction condition of data transmission in the H-EDT state, and the like) can be configured in combination with the service characteristics of the terminal device, so that the terminal device can be provided with on-demand mobility management. Optionally, the network can configure the related parameters of the H-EDT state in combination with the characteristics and needs 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 configuration of the H-EDT state can be performed according to the QoS class identifier (QCI; where QoS is the abbreviation of quality of service) of the terminal device.

[0137] For example, the related parameters of the condition to be met by the terminal device when entering the H-EDT state can include one or more of the following:

[0138] - a 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;

[0139] - a time threshold: when the duration of the service corresponding to the terminal device is less than or equal to the time threshold, the terminal device can change from the RRC connected state to the H-EDT state;

[0140] - a service type: the terminal device can change from the RRC connected state to the H-EDT state if 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 a small amount of data, or a service with a short duration, or a service with a low requirement for log transmission efficiency, for example, an IOT service, a short message service, a voice service, or a signaling data transmission service, which is not limited in the present application.

[0141] - a QoS level threshold: the terminal device can change from the RRC connected state to the H-EDT state if 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).

[0142] - a timer parameter, for example, the duration of a timer. The timer can include one or more of the following: a first timer, a second timer, and a third timer. The first timer is used to time the duration of the RRC connected state, and when the first timer expires, the terminal device changes from the RRC connected state to the H-EDT state. The second timer is used to time the duration of the H-EDT state, and when the terminal device enters the H-EDT state, the second timer is started, and when the second timer expires, the terminal device enters the RRC connected state. The third timer is used to determine whether the terminal device continuously meets the condition for changing to the H-EDT state within a certain duration, and when the third timer expires, it indicates that the terminal device continuously meets the condition for changing to the H-EDT state within a certain duration, and at this time the terminal device can request the network device to change it from the RRC connected state to the H-EDT state.

[0143] For example, the related parameters of the restriction condition of log transmission in the H-EDT state can include one or more of the following:

[0144] - a transmission duration threshold: the duration of data transmission between the terminal device in the H-EDT state and the network side is less than or equal to the transmission duration threshold;

[0145] - a data packet size threshold: the size of the data packet transmitted by the terminal device in the H-EDT state during data transmission is less than or equal to the data packet size threshold.

[0146] 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.

[0147] In a possible implementation, the RRC states of the terminal device can include: an RRC connected state, an RRC idle state, and an 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, the RRC states of the terminal device can include: an RRC connected state, an RRC idle state, an RRC inactive state, and an 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 switch between different RRC states. FIG. 5 shows a schematic diagram of switching between different RRC states, taking the RRC states including the RRC connected state, the RRC idle state, and the H-EDT state as an example, and FIG. 6 shows a schematic diagram of switching between different RRC states, taking the RRC states including the RRC connected state, the RRC idle state, the RRC inactive state, and the H-EDT state as an example.

[0148] As shown in FIG. 5 and FIG. 6, the terminal device in the RRC connected state can stop measuring the periodic reference signal while maintaining the RRC connection with the network device, thereby entering the H-EDT state, and the network device retains the context information of the terminal device. The terminal device in the H-EDT state resumes measuring the periodic reference signal while maintaining the RRC connection with the network device, thereby entering the RRC connected state, and the network device retains the context information of the terminal device. The terminal device in the H-EDT state can enter the RRC idle state after releasing the RRC connection. For the terminal device in the RRC idle state, the network device no longer retains the context information of the terminal device.

[0149] The terminal device in the H-EDT state can enter the RRC inactive state after releasing the RRC connection and stopping measuring the reference signal sent along with the channel. For the terminal device in the RRC inactive state, the network device retains the context information of the terminal device.

[0150] The switching between the RRC connected state and the RRC idle state, the switching between the RRC connected state and the RRC inactive state, and the switching from the RRC inactive state to the RRC idle state can refer to FIG. 4 and the related description.

[0151] The other characteristics of the terminal device in the H-EDT state can refer to the description above, for example, the terminal device in the H-EDT state can measure the reference signal sent along with the channel.

[0152] It should be understood that in the present application, “transition”, “switch”, “enter”, “release”, and “change” are all used to describe the change of the RRC state, and can be replaced with each other. For example, the transition from the RRC connected state to the RRC inactive state can be expressed as “transition from RRC_CONNECTED to RRC_INACTIVE”.

[0153] It should be understood that, in this application, "stop", "suspend", "suspend", "suspend", "pause", "cancel" or "cancel" can be replaced by each other. For example, "stopping the measurement of the periodic reference signal" can also be expressed as "canceling the measurement of the periodic reference signal".

[0154] 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. 7 shows a flow diagram of a terminal device changing from an RRC connected state to an 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 herein can be a control center in the above-mentioned application scenarios such as smart grid, industrial control, intelligent transportation, smart city, etc. 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.

[0155] As shown in FIG. 7, the flow can include the following steps:

[0156] Step 701: The terminal device in the RRC connected state sends service information and / or state change tendency information to the network device.

[0157] The service information can include uplink service information or downlink service information, and the service information and state change tendency information can be used to make a decision on RRC state change.

[0158] Optionally, the service information can include one or more of the following: service data volume, service data volume change trend (used to reflect the distribution of data volume over time, such as 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.

[0159] The service data volume can be estimated by the terminal device according to the service type. The 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.

[0160] 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.

[0161] 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.

[0162] Optionally, the state change tendency information can be determined by the terminal device based on the service information.

[0163] For example, if the service information satisfies one or more of the following conditions, the terminal device can suggest changing from the RRC connected state to the H-EDT state:

[0164] 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 terminal device's downlink data transmission 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.

[0165] 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 terminal device's downlink data transmission 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.

[0166] Condition 3: The data volume of the service corresponding to the terminal device has a downward trend, indicating that the data volume of the terminal device's downlink data transmission 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.

[0167] 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 terminal device has a small amount of downlink data transmission, a short duration, or a low requirement for log transmission efficiency. In this case, in order to reduce the power consumption of the terminal device, the terminal device can be changed from the RRC connected state to the H-EDT state.

[0168] Condition 5: the QoS level of the service corresponding to the terminal device is lower than or equal to the QoS level threshold, indicating that the terminal device has a low requirement for log transmission efficiency. In this case, in order to reduce the power consumption of the terminal device, the terminal device can be changed from the RRC connected state to the H-EDT state.

[0169] 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.

[0170] 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.

[0171] Optionally, the state change tendency information can further include first duration information, the first duration information being used to indicate the duration of the RRC state (herein, the H-EDT state is taken as an example) suggested by the terminal device. The network device can determine the duration of the terminal device in the H-EDT state according to the first duration information.

[0172] 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:

[0173] Condition a: the data amount of the service corresponding to the terminal device is less than 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;

[0174] Condition b: the data amount of the service corresponding to the terminal device has a downward trend;

[0175] Condition c: the duration of the service corresponding to the terminal device is less than or equal to a duration threshold.

[0176] 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 according to the service information and / or the state change tendency information in subsequent steps.

[0177] Based on the system architecture shown in FIG. 3, in step 701, the terminal device sends service information and / or state change tendency information to the O-CU (e.g., 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 according to the service information and / or state change tendency information in subsequent steps.

[0178] Step 701 is an optional step.

[0179] 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.

[0180] 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 for determining whether to change the terminal device from the RRC connected state to the H-EDT state according to the service information in step 701.

[0181] 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.

[0182] 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 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.

[0183] 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 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, it 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, it decides to change the terminal device from the RRC connected state to the H-EDT state.

[0184] 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 while adding indication information in the F1 signaling, which is used to indicate that the change trend of the buffered data volume is decreasing, 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.

[0185] 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 while adding indication information in the F1 signaling, which is used to indicate that the change trend of the buffered data volume is decreasing, 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.

[0186] 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 stored on the network device, and record the current RRC state of the terminal device as the H-EDT state.

[0187] Step 703: The network device sends first indication information to the terminal device.

[0188] The first indication information is used to indicate that the terminal device is changed from the RRC connected state to the H-EDT state.

[0189] Optionally, the first indication information is carried in L1 signaling or L2 signaling. The L1 signaling is sent by the L1 layer (that is, the physical layer), for example, the L1 signaling can be downlink control information (DCI). The L2 signaling is sent by the L2 layer (that is, the MAC layer), for example, the L2 signaling can be a MAC CE (CE is the abbreviation of control element, that is, control unit).

[0190] Based on the system architecture shown in FIG. 2, in step 703, the CU (for example, the 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 the first indication information to the terminal device according to the F1 instruction.

[0191] Based on the system architecture shown in FIG. 3, in step 701, the O-CU (for example, O-CU-CP) in the RAN sends an F1 signaling to the O-DU, and the F1 instruction can include indication information, which can be used to indicate that the H-EDT state is changed. The O-DU sends first indication information to the terminal device according to the F1 instruction.

[0192] Step 704: The terminal device enters the H-EDT state according to the first indication information. In the H-EDT state, the terminal device maintains the RRC connection with the network device and stops measuring the periodic reference signal.

[0193] Optionally, the terminal device can also send RRC state change confirmation information to the network device to inform the terminal device that the H-EDT state is changed.

[0194] In a possible implementation, in the H-EDT state, the terminal device can receive a reference signal sent 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.

[0195] In a possible implementation, in the H-EDT state, the terminal device can receive a reference signal of at least one cell according to a first period, and can perform cell switching or cell switching decision based on the reference signal.

[0196] 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. 8 shows a flowchart of changing the terminal device from the H-EDT state to the 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 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.

[0197] As shown in FIG. 8, the flowchart can include the following steps:

[0198] Step 801: The terminal device in the H-EDT state sends service information and / or state change tendency information to the network device.

[0199] In this step, the content of the service information and the obtaining manner can refer to step 701 in the flow shown in FIG. 7.

[0200] In this step, the RRC state indicated by the state change tendency information is the RRC connected state, which indicates that the RRC state suggested by the terminal device is the RRC connected state.

[0201] 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:

[0202] 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.

[0203] 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.

[0204] 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.

[0205] Condition 4: The type of the service corresponding to the terminal device is not the type of the service specified in the configuration information of the H-EDT state, indicating that the data volume of the downlink transmission of the terminal device is large, or the time length is long, or the requirement for data transmission efficiency is high. 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.

[0206] Condition 5: The QoS level of the service corresponding to the terminal device is higher than a QoS level threshold, indicating that the downlink data transmission of the terminal device has a high requirement for data transmission efficiency. 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.

[0207] 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.

[0208] 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.

[0209] Optionally, the state change tendency information can further include second duration information, the second duration information being used to indicate a duration of the RRC state (here taking the RRC connected state as an example) suggested by the terminal device. The network device can determine the duration of the RRC connected state of the terminal device according to the second duration information.

[0210] 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:

[0211] Condition a: the data volume of the service corresponding to the terminal device is greater than or equal to a threshold, which can be equal to or different from the aforementioned data volume threshold, and the present application does not limit this;

[0212] Condition b: the data volume of the service corresponding to the terminal device has an upward trend;

[0213] Condition c: the duration of the service corresponding to the terminal device is greater than a duration threshold.

[0214] 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.

[0215] Based on the system architecture shown in FIG. 3, in step 801, 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 H-EDT state to the RRC connected state according to the service information and / or the state change tendency information in subsequent steps.

[0216] Step 801 is an optional step.

[0217] 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.

[0218] 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 of the terminal device for determining whether to change from the H-EDT state to the RRC connected state according to the service information for determining whether to change the terminal device from the H-EDT state to the RRC connected state.

[0219] 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 sent by the terminal device according to the RRC state indicated by the state change tendency information.

[0220] 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.

[0221] 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 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 greater than a data volume threshold, the network device 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 volume change trend of the service corresponding to the terminal device is an upward trend, the network device decides to change the terminal device from the H-EDT state to the RRC connected state.

[0222] 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 to indicate that the change trend of the buffered data volume is upward or 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 to indicate that the terminal device is changed from the H-EDT state to the RRC connected state.

[0223] 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 to indicate that the change trend of the buffered data volume is upward or 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 to indicate that the terminal device is changed from the H-EDT state to the RRC connected state.

[0224] In a possible implementation, after the network device determines 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 saved on the network device, and record the current RRC state of the terminal device as the RRC connected state.

[0225] Step 803: The network device sends second indication information to the terminal device.

[0226] The second indication information is used for indicating the change from the H-EDT state to the RRC connected state.

[0227] Optionally, the second indication information is carried in L1 signaling or L2 signaling.

[0228] Based on the system architecture shown in FIG. 2, in step 803, the CU (for example, the CU-CP) in the RAN sends an F1 signaling to the DU, the F1 signaling can include indication information, which can be used to indicate the change to the RRC connected state, and the DU sends the second indication information to the terminal device according to the F1 signaling.

[0229] Based on the system architecture shown in FIG. 3, in step 803, the O-CU (for example, the O-CU-CP) in the RAN sends an F1 signaling to the O-DU, the F1 signaling can include indication information, which can be used to indicate the change to the RRC connected state, and the O-DU sends the second indication information to the terminal device according to the F1 signaling.

[0230] In step 804, the terminal device enters the RRC connected state according to the second indication information.

[0231] In the RRC connected state, the terminal device resumes the measurement on the periodic reference signal.

[0232] Optionally, the terminal device can also send RRC state change confirmation information to the network device, to inform the terminal device that the change to the RRC connected state.

[0233] In a possible implementation, in the RRC connected state, the terminal device no longer detects the reference signal sent along with the road. 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.

[0234] In a possible implementation, in the RRC connected state, the terminal device can detect the reference signal of the current cell and the neighboring cell according to a second period, and can perform cell switching or cell switching decision based on the reference signal.

[0235] 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 flow diagram of changing the RRC state of a terminal device from H-EDT state to 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 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.

[0236] As shown in FIG. 9, the flow can include the following steps:

[0237] Step 901: The network device determines to change the RRC state of the terminal device from H-EDT state to RRC idle state.

[0238] Optionally, when the network device determines that the terminal device has no data transmission for a long time, it can decide to change the terminal device from H-EDT state to RRC idle state to save power consumption.

[0239] Step 902: The network device sends third indication information to the terminal device.

[0240] The third indication information is used to indicate the change from H-EDT state to RRC idle state.

[0241] Optionally, the third indication information is carried in L3 signaling. The L3 signaling is sent by the L3 layer (i.e. the RRC layer), for example, the L3 signaling is an RRC message, more specifically, the L3 signaling is an RRC connection release message.

[0242] Step 903: The terminal device enters RRC idle state according to the third indication information.

[0243] 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 saved on the network device, and record the current RRC state of the terminal device as RRC idle state.

[0244] 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 flow diagram of changing the RRC state of a terminal device from H-EDT state to 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 modem) in the terminal device, or by a device containing the functions of the terminal device.

[0245] As shown in FIG. 10, the flow can include the following steps:

[0246] Step 1001: The network device determines to change the RRC state of the terminal device from H-EDT state to RRC inactive state.

[0247] Optionally, when the network device determines that the terminal device has no data transmission for a long time, it can decide to change the terminal device from H-EDT state to RRC inactive state to save power consumption.

[0248] Step 1002: The network device sends fourth indication information to the terminal device.

[0249] The fourth indication information is used to indicate the change from H-EDT state to RRC inactive state.

[0250] Optionally, the third indication information is carried in L3 signaling. The L3 signaling is sent by the L3 layer (i.e. the RRC layer), for example, the L3 signaling is an RRC message, more specifically, the L3 signaling is an RRC connection release message.

[0251] Step 1003: The terminal device enters RRC inactive state according to the fourth indication information.

[0252] In the RRC inactive state, the RRC connection between the terminal device and the network device is released, the context information of the terminal device is retained on the network device, and the network device can record the current RRC state of the terminal device as RRC inactive state.

[0253] 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. 11 shows a flow diagram of another process 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 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.

[0254] As shown in FIG. 11, the process can include the following steps:

[0255] Steps 1101a and 1101b: The terminal device in the RRC connected state and the network device start a first timer at a first time.

[0256] In one possible implementation, after the terminal device accesses the network, the terminal device negotiates with the network device to start the first timer. Here, the terminal device and the network device negotiate to determine to start the first timer at the first time. For example, the first time is the time when the RRC connection is established, or a certain time after the RRC connection is established.

[0257] In another possible implementation, the terminal device and the network device configure the first timer according to the configuration information of the H-EDT state. After the terminal device accesses the network and establishes the RRC connection, the network device can send signaling (such as DCI) to the terminal device to instruct the terminal device to start the first timer at the first time, and at the same time, the network device also starts the first timer at the first time.

[0258] Step 1102: At the terminal device side, when the first timer expires, the terminal device enters the H-EDT state. In the H-EDT state, the terminal device maintains the RRC connection with the network device and stops measuring the periodic reference signal.

[0259] Optionally, during the running of the first timer, if the terminal device determines to extend the duration of the H-EDT state, the first timer can be restarted so that the first timer starts counting again.

[0260] For example, the terminal device can determine to extend the duration of the H-EDT state in the following cases:

[0261] Condition 1: The total data amount of the service corresponding to the terminal device is less than or equal to a data amount threshold;

[0262] Condition 2: the data volume of the service corresponding to the terminal device has a downward trend.

[0263] Optionally, the network device can send a notification message to the terminal device to inform the terminal device to restart the first timer when it is determined to restart the first timer.

[0264] Optionally, the network device can send a notification message to the terminal device to inform the terminal device to restart the first timer when it is determined to restart the first timer.

[0265] The operation of the terminal device when entering the H-EDT state and the operation of the terminal device in the H-EDT state can refer to the foregoing embodiments.

[0266] Step 1103: On the network device side, when the first timer expires, the RRC connection with the terminal device is maintained, and the terminal device is changed from the RRC connected state to the H-EDT state.

[0267] Optionally, when the first timer expires, the network device can update the context information of the terminal device and record the RRC state of the terminal device as the H-EDT state. Other operations of the network device for the terminal device in the H-EDT state can refer to the foregoing embodiments.

[0268] Optionally, during the running of the first timer, if the network device determines to extend the duration of the H-EDT state, the first timer can be restarted so that the first timer starts counting again.

[0269] Optionally, the network device can determine to extend the duration of the H-EDT state in the following cases:

[0270] Condition 1: the total data volume of the service corresponding to the terminal device is less than or equal to the data volume threshold;

[0271] Condition 2: the data volume of the service corresponding to the terminal device has a downward trend.

[0272] Optionally, the network device can send a notification message to the terminal device to inform the terminal device to restart the first timer when it is determined to restart the first timer.

[0273] Optionally, the network device can send a notification message to the terminal device to inform the terminal device to restart the first timer when it is determined to restart the first timer.

[0274] Based on the flow shown in FIG. 11, the terminal device and the network side can count the duration of the RRC connected state based on the timer, and change from the RRC connected state to the H-EDT state when the timer expires, thereby realizing the timer-based state conversion.

[0275] 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. 12 shows another flow schematic diagram of the terminal device converting from the H-EDT state to the RRC connected state. 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 can be executed 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 can be executed by a device containing the functions of the terminal device.

[0276] As shown in FIG. 12, the flow can include the following steps:

[0277] Steps 1201a and 1201b: The terminal device and the network device in the RRC connected state start a second timer at a third time.

[0278] In a possible implementation, after the terminal device accesses the network, the terminal device negotiates with the network device to start the second timer. Here, the terminal device and the network device negotiate to determine to start the second timer at the third time. For example, the third time is the time when the terminal device enters the H-EDT state.

[0279] Step 1202: At the terminal device side, when the second timer expires, the terminal device enters the RRC connected state. In the RRC connected state, the terminal device maintains the RRC connection with the network device and resumes the measurement on the periodic reference signal.

[0280] Optionally, during the running of the second timer, if the terminal device determines to extend the duration of the RRC connected state, the second timer can be restarted so that the second timer starts counting again.

[0281] For example, the terminal device can determine to extend the duration of the RRC connected state in the following cases:

[0282] Condition 1: The total data amount of the service corresponding to the terminal device is greater than a data amount threshold;

[0283] Condition 2: The data amount of the service corresponding to the terminal device has an upward trend.

[0284] Optionally, when the terminal device decides to restart the second timer, or before restarting the second timer, it may send a notification message to the network device to notify the network device to restart the second timer.

[0285] For example, the terminal device can send a notification message to the network device to notify the network device to restart the second timer at the fourth moment during the second timer's operation, and the terminal device also restarts the second timer at the fourth moment.

[0286] Step 1203: On the network device side, when the second timer expires, maintain the RRC connection with the terminal device and change the terminal device from H-EDT state to RRC connection state.

[0287] Optionally, when the second timer expires, the network device may update the context information of the terminal device and record the RRC status of the terminal device as RRC connected state.

[0288] Optionally, if the network device determines to extend the duration of the RRC connection state during the operation of the second timer, the second timer can be restarted to restart the timing.

[0289] For example, a network device may determine the duration of an extended H-EDT state in the following circumstances:

[0290] Condition 1: The total data volume of the services corresponding to this terminal device is greater than the data volume threshold;

[0291] Condition 2: The data volume of the service corresponding to this terminal device shows an upward trend.

[0292] Optionally, when the network device decides to restart the second timer, or before restarting the second timer, it may send a notification message to the terminal device to notify the terminal device to restart the second timer.

[0293] For example, the network device can send a notification message to the terminal device to notify the terminal device to restart the first timer at the fourth moment during the second timer's operation, and the terminal device also restarts the timer at the fourth moment.

[0294] Based on the process shown in Figure 11 above, the terminal device and the network side can time the duration of the H-EDT state based on a timer, and change from the H-EDT state to the RRC connection state when the timer expires, thus realizing the state transition based on the timer.

[0295] 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. 13 shows a flowchart of another process of transitioning from the RRC connected state to the H-EDT state by the terminal device. 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.

[0296] As shown in FIG. 13, the process can include the following steps:

[0297] Step 1301: The terminal device counts the amount of data transmitted in the RRC connected state.

[0298] The amount of data transmitted can be the amount of downlink data received by the terminal device, or the amount of uplink data sent by the terminal device.

[0299] In this step, the amount of data can be counted by the MAC layer of the terminal device, or by the RRC layer.

[0300] Step 1302: When the counted amount of data meets the first condition, start a third timer.

[0301] In one possible implementation, the first condition is that the counted amount of data is less than or equal to a threshold value. For example, the terminal device can count the amount of data of N consecutive scheduled downlink transmissions, and if the amount of data of each scheduling in the N times of scheduling is less than a preset threshold, it indicates that the amount of data transmission is small. At this time, the terminal device starts the third timer.

[0302] In another possible implementation, the first condition is that the trend of the counted amount of data is decreasing. For example, the terminal device can count the amount of data of N consecutive scheduled downlink transmissions, and if the trend of the amount of data of the N times of scheduling is decreasing, the terminal device starts the third timer at this time.

[0303] Step 1303: During the running of the third timer, if the counted amount of data does not meet the first condition, stop the third timer.

[0304] Step 1304: When the third timer times out, send a request message to the network device. The request message is used to request to change to the H-EDT state.

[0305] Step 1305: The network device sends indication information to the terminal device, where the indication information is used to indicate that the RRC connected state is changed to the H-EDT state.

[0306] Step 1306: The terminal device enters the H-EDT state according to the indication information.

[0307] The operation of the terminal device when entering the H-EDT state and the operation of the terminal device in the H-EDT state can refer to the foregoing embodiments. The operation of the network device for the terminal device in the H-EDT state can refer to the foregoing embodiments.

[0308] Based on the flow shown in FIG. 13, when the terminal device counts that the data volume meets the first condition, the terminal device does not immediately change to the H-EDT state, but starts a third timer. Only when the data volume counted during the running of the third timer still meets the first condition, the terminal device requests to change to the H-EDT state, so that the data transmission efficiency can be guaranteed, and the reliability can be improved.

[0309] It can be understood that the RRC state conversion flows shown in FIGS. 7 to 13 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 RRC connected state to the H-EDT state based on the flow shown in FIG. 7 or FIG. 13, and then change from the H-ECT state to the RRC connected state based on the flow shown in FIG. 12.

[0310] It can be understood that, in order to implement the functions in the foregoing embodiments, the network device and the terminal device include 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 implemented in hardware or computer software driven hardware depends on the specific application scenarios and design constraints of the technical solutions.

[0311] FIGS. 14 and 15 are structural schematic diagrams of possible communication apparatuses provided by the embodiments of the present application. The communication apparatuses can be used to implement the functions of the terminal device or the network device in the foregoing method embodiments, and thus can also achieve the beneficial effects possessed by the foregoing 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.

[0312] As shown in FIG. 14, the communication apparatus 1400 includes a processing unit 1410 and a transceiver unit 1420. The communication apparatus 1400 is configured to implement the functions of the terminal device or the network device in the method embodiments shown in FIG. 3.

[0313] When the communication apparatus 1400 is configured to implement the functions of the terminal device in the method embodiments shown in FIG. 7, the transceiver unit 1420 is configured to receive first indication information, the first indication information being used to indicate that the terminal device changes from the RRC connected state to a first state; and the processing unit 1410 is configured to enter the first state according to the first indication information, and the terminal device, in the first state, maintains the RRC connection between the terminal device and the network device, and stops the measurement of the periodic reference signal.

[0314] When the communication apparatus 1400 is configured to implement the functions of the network device in the method embodiments shown in FIG. 7, the processing unit 1410 is configured to maintain the RRC connection with the terminal device; and the processing unit 1410 is further configured to send, through the transceiver unit 1420, first indication information, the first indication information being used to indicate that the terminal device changes from the RRC connected state to a first state; and wherein the terminal device, in the first state, maintains the RRC connection with the network and stops the measurement of the periodic reference signal.

[0315] When the communication apparatus 1400 is configured to implement the functions of the terminal device in the method embodiments shown in FIG. 8, the transceiver unit 1420 is configured to receive, in the first state, 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 the processing unit 1410 is configured to enter the RRC connected state according to the second indication information, and the terminal device, in the RRC connected state, resumes the measurement of the periodic reference signal. Wherein, in the first state, the RRC connection between the terminal device and the network device is maintained, and the measurement of the periodic reference signal is stopped.

[0316] When the communication apparatus 1400 is configured to implement the functions of the network device in the method embodiments shown in FIG. 8, the processing unit is configured to send, through the transceiver unit 1420, second indication information to the terminal device when the terminal device is in a first state, the second indication information being used to indicate that the terminal device changes from the first state to the RRC connected state. Wherein, in the first state, the RRC connection between the terminal device and the network device is maintained, and the measurement of the periodic reference signal is stopped.

[0317] When the communication apparatus 1400 is configured to implement the function of the terminal device in the method embodiment shown in FIG. 10, the transceiver 1420 is configured to, in a first state, receive 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; the processing unit 1410 is configured to enter the RRC inactive state according to the fourth indication information, and in the RRC inactive state, the RRC connection between the terminal device and the network device is released. In the first state, the RRC connection between the terminal device and the network device is maintained, and the measurement on the periodic reference signal is stopped.

[0318] When the communication apparatus 1400 is configured to implement the function of the network device in the method embodiment shown in FIG. 10, the processing unit 1410 is configured to, when the terminal device is in a first state, send, by the transceiver 1420, fourth indication information to the terminal device, the fourth indication information being used to indicate that the terminal device changes from the first state to an RRC inactive state; release the RRC connection between the network device and the terminal device, and retain the context information of the terminal device. In the first state, the RRC connection between the terminal device and the network device is maintained, and the measurement on the periodic reference signal is stopped.

[0319] When the communication apparatus 1400 is configured to implement the function of the terminal device in the method embodiment shown in FIG. 11, the processing unit 1410 is configured to start a first timer at a first time point in an RRC connected state; and when the first timer expires, make the terminal device enter a first state, and in the first state, the terminal device maintains the RRC connection between the terminal device and the network device, and stops the measurement on the periodic reference signal.

[0320] When the communication apparatus 1400 is configured to implement the function of the network device in the method embodiment shown in FIG. 11, the processing unit 1410 is configured to start a first timer at a first time point when the terminal device is in an RRC connected state; and when the first timer expires, change the terminal device from the RRC connected state to a first state, and in the first state, the RRC connection between the terminal device and the terminal device is maintained; and in the first state, the terminal device stops the measurement on the periodic reference signal.

[0321] When the communication apparatus 1400 is configured to implement the function of the terminal device in the method embodiment shown in FIG. 12, the processing unit 1410 is configured to, in a first state, start a second timer at a third time point; and when the second timer expires, make the terminal device enter an RRC connected state, and in the RRC connected state, the terminal device resumes the measurement on the periodic reference signal.

[0322] When the communication apparatus 1400 is configured to implement the function of the network device in the method embodiment shown in FIG. 12, the processing unit 1410 is configured to start a second timer at a third time point when the terminal device is in a first state; and change the terminal device from the first state to an RRC connected state when the second timer expires.

[0323] When the communication apparatus 1400 is configured to implement the function of the terminal device in the method embodiment shown in FIG. 13, the processing unit 1410 is configured to start a third timer when the amount of transmitted data meets a first condition in an RRC connected state; stop the third timer if the amount of transmitted data does not meet the first condition during the running of the third timer; and send a request message through the transceiver 1420 when the third timer expires, the request message being used to request to change to a first state; wherein the terminal device in the first state maintains RRC connection with the network device and stops measuring the periodic reference signal.

[0324] The more detailed description of the processing unit 1410 and the transceiver 1420 can be directly obtained by referring to the related description in the method embodiment shown in FIG. 3, which will not be repeated here.

[0325] As shown in FIG. 15, the communication apparatus 1500 includes a processor 1510 and an interface circuit 1520. The processor 1510 and the interface circuit 1520 are coupled with each other. It can be understood that the interface circuit 1520 can be a transceiver or an input / output interface. Optionally, the communication apparatus 1500 can further include a memory 1530 for storing instructions executed by the processor 1510 or storing input data required by the processor 1510 for running instructions or storing data generated after the processor 1510 runs instructions.

[0326] When the communication apparatus 1500 is configured to implement the method shown in FIG. 3, the processor 1510 is configured to implement the function of the processing unit 1410, and the interface circuit 1520 is configured to implement the function of the transceiver 1420.

[0327] 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; 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.

[0328] When the communication apparatus is a module applied to a network device, the network device module implements the functions of the network device in the method embodiments. 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 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. The network device module herein can be a baseband chip of the network device, or a DU or other module, and the DU herein can be a DU under the open radio access network (O-RAN) architecture.

[0329] 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 (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor can be a microprocessor or any conventional processor.

[0330] In the present application, another example of a communication apparatus is provided, which includes at least one processor and at least one memory coupled to the at least one processor, the at least one memory configured to store instructions that, when executed by the at least one processor, cause the communication apparatus to perform the method in the above embodiments. Taking the communication apparatus including one processor and one memory as an example, as shown in FIG. 15, the communication apparatus 1500 includes one processor 1510 and one memory 1530. The processor 1510 and the memory 1530 are coupled, and the memory 1530 stores instructions. When the instructions stored in the memory 1530 are executed by the processor 1510, the communication apparatus 1500 performs the method executed by the terminal device or the network device in the above embodiments.

[0331] The method steps in the embodiments of the present application can be implemented in hardware or in software instructions executable by a processor. The software instructions can be composed of corresponding software modules, which can be stored in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable 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 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 a network device or a terminal. The processor and the storage medium can also exist as discrete components in the network device or the terminal.

[0332] In the above embodiments, the implementation can be entirely or partially achieved by software, hardware, firmware, or any combination thereof. When implemented by software, the implementation can be entirely or partially 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, the processes or functions described in the embodiments of the present application are entirely or partially 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 devices. 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, computer, server, or data center to another website, computer, server, or data center through a wired or wireless manner. The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media. The available medium can be a magnetic medium, such as a floppy disk, a hard disk, a magnetic tape; 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.

[0333] In various embodiments of the present application, the terms and / or descriptions of different embodiments are consistent and can be mutually referenced if there is no special description and no logical conflict. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0334] In the present application, "at least one" means one or more, "multiple" means two or more. The "and / or" describes the relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B, which can represent: A exists alone, A and B exist together, B exists alone, where A, B can be singular or plural. In the text description of the present application, the character " / ", generally indicates that the associated objects before and after are in an "or" relationship; in the formula of the present application, the character " / ", indicates 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.

[0335] It can be understood that various numerical 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 its function and inherent logic.

Claims

1. A communication method characterized by comprising: The application is applied to a terminal device, comprising: receiving first indication information, wherein 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, wherein the terminal device keeps RRC connection between the terminal device and a network device in the first state, and stops measurement on a periodic reference signal.

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

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

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

5. The method of claim 4, wherein, The state change tendency information comprises first duration information, wherein the first duration information is used to indicate a duration of the first state.

6. The method according to any one of claims 4-5, wherein, The sending of the state change tendency information comprises: when one or more of the following conditions are met, the state change tendency information is sent: the service data volume is less than or equal to a data volume threshold; the service data volume change trend is a downward trend; the service duration is less than or equal to a duration threshold.

7. The method according to any one of claims 1 to 6, wherein 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 reference signal for the terminal device in the RRC connected state; performing cell switching according to the reference signal of the at least one cell.

8. The method according to any one of claims 1 to 7, wherein, In the first state, the terminal device further comprises: receiving downlink data and a reference signal sent along with the downlink data; measuring the reference signal to obtain a measurement result; sending the measurement result.

9. The method according to any one of claims 1 to 8, wherein, 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; entering the RRC connected state according to the second indication information, wherein the terminal device resumes measurement on the periodic reference signal in the RRC connected state.

10. The method of claim 9, wherein, Before the receiving of the second indication information, the method 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.

11. The method of any one of claims 1-8, wherein, 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 an RRC idle state; entering the RRC idle state according to the third indication information, wherein the RRC connection between the terminal device and the network device is released in the RRC idle state.

12. The method of any one of claims 1-8, wherein, In the first state, the terminal device further comprises: receiving fourth indication information, wherein the fourth indication information is used to indicate that the terminal device changes from the first state to an RRC inactive state; According to the fourth indication information, the terminal device enters the RRC inactive state. In the RRC inactive state, the RRC connection between the terminal device and the network device is released.

13. A method of communication, comprising: Applied to a network device, comprising: Maintain a radio resource control (RRC) connection with a terminal device; Send first indication information, the first indication information is used to indicate that the terminal device changes from the RRC connected state to a first state; wherein the terminal device in the first state maintains the RRC connection with the network and stops measuring the periodic reference signal.

14. The method of claim 13, wherein, Before the first indication information is sent, further comprising: Receiving service information corresponding to the terminal device; According to the service information, it is determined to change the terminal device from the RRC connected state to the first state.

15. The method of claim 14, wherein, The service information includes one or more of the following: service data volume, service data volume trend, service duration and service type.

16. The method of claim 13, wherein, Before the first indication information is sent, further comprising: Receiving state change tendency information of the terminal device, the state change tendency information indicating the first state; According to the state change tendency information, it is determined to change the terminal device from the RRC connected state to the first state.

17. The method of claim 16, wherein, The state change tendency information includes first time length information, the first time length information is used to indicate the duration of the first state; The method further comprises: According to the first time length information, the length of time that the terminal device is in the first state is determined.

18. The method of any one of claims 13-17, wherein, Further comprising: Stop sending periodic reference signals to the terminal device; and / or Stop measuring the reference signal periodically sent by the terminal device.

19. The method of any one of claims 13-18, wherein, After the first indication information is sent, further comprising: Send 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.

20. The method of claim 19, wherein, Further comprising: Receiving service information corresponding to the terminal device; According to the service information, it is determined to change the terminal device from the first state to the RRC connected state.

21. The method of claim 19, wherein, Further comprising: Receiving state change tendency information of the terminal, the state change tendency information indicating the RRC connected state; According to the state change tendency information, it is determined to change the terminal device from the first state to the RRC connected state.

22. The method of any one of claims 19-21, wherein, Further comprising: Restore sending periodic reference signals to the terminal device; and / or Restore measuring the reference signal periodically sent by the terminal device.

23. The method of any one of claims 13-18, wherein, After the first indication information is sent, further comprising: Send third indication information, the third indication information is used to indicate that the terminal device changes from the first state to the RRC idle state; Release the RRC connection with the terminal device.

24. The method of any one of claims 13-18, wherein, After the first indication information is sent, further comprising: Send 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; Release the RRC connection with the terminal device and retain the context information of the terminal.

25. A communications device, characterized by Comprise a unit or module for executing the method as claimed in any one of claims 1-12, or comprise a unit or module for executing the method as claimed in any one of claims 13-24.

26. A communications device, characterized by Comprise: One or more processors configured to perform the method of any one of claims 1-12, or perform the method of any one of claims 13-24.

27. A readable storage medium characterized by, The readable storage medium stores programs or instructions, when the programs or instructions run on the device, make the device execute the method of any one of claims 1-12, or execute the method of any one of claims 13-24.

28. A chip system, characterized by The computer program product comprises a program; when the computer program runs on the computer, makes the computer execute the method of any one of claims 1-12, or execute the method of any one of claims 13-24.

29. A computer program product, characterised in that, The computer program product comprises a program; when the computer program runs on the computer, makes the computer execute the method of any one of claims 1-12, or execute the method of any one of claims 13-24.

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