CN113518395A

CN113518395A - Information transmission method and device

Info

Publication number: CN113518395A
Application number: CN202010277841.2A
Authority: CN
Inventors: 娄崇; 范强; 韩锋
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-04-10
Filing date: 2020-04-10
Publication date: 2021-10-19
Also published as: WO2021204254A1

Abstract

The application provides an information transmission method and device, and the method comprises the following steps: a first network device sends a first message to a second network device, wherein the first message is used for requesting to switch a terminal device from a first cell to a second cell, the first cell belongs to the first network device, and the second cell belongs to the second network device; the first network equipment receives a response message to the first message from the second network equipment, wherein the response message comprises reference time information; the first network device sends the reference time information to the terminal device. The embodiment of the application is beneficial to avoiding the influence on the service performance of the terminal equipment caused by the sending delay of the reference time in the switching process.

Description

Information transmission method and device

Technical Field

The present application relates to the field of communications, and more particularly, to a method and apparatus for information transmission.

Background

In a conventional Handover (HO) procedure of a mobile communication system, mobility management of a terminal device in a connected state is controlled by a network device, that is, the network device instructs the terminal device to which cell and how to perform handover by sending a handover message. After receiving the handover message, the terminal device accesses the target cell according to the content contained in the handover message, so that the successful sending of the handover message is a necessary condition for ensuring the successful handover under the conventional handover mechanism.

At present, the terminal equipment can only request reference time after executing the switching process and establishing connection with the target base station. For some services of the terminal device, if these services are still in progress during the handover process, the transmission delay of the reference time may affect the performance of these services.

Disclosure of Invention

The application provides an information transmission method and device, which are beneficial to avoiding the influence on the service performance of terminal equipment caused by the sending delay of reference time in the switching process.

In a first aspect, an information transmission method is provided, where the method includes: a first network device sends a first message to a second network device, wherein the first message is used for requesting to switch a terminal device from a first cell to a second cell, the first cell belongs to the first network device, and the second cell belongs to the second network device; the first network equipment receives a response message to the first message from the second network equipment, wherein the response message comprises reference time information; the first network device sends the reference time information to the terminal device.

In the embodiment of the application, the second network device can send the reference time information to the first network device in the switching process, and the reference time information is sent to the terminal device by the first network device, so that the terminal device can obtain the reference time information in the switching process, and the influence of the sending delay of the reference time on the service performance of the terminal device is favorably avoided.

In some possible implementations, if there is an interface between the first network device and the second network device, the first message is a handover request message.

In some possible implementations, if there is no interface between the first network device and the second network device. The first network device may send the first message to the core network device, where the first message is a handover required message. After receiving the handover required message, the core network device may send a handover request message to the second network device.

With reference to the first aspect, in certain implementations of the first aspect, the reference time information includes information of a reference time and information of a reference point corresponding to the reference time.

In the embodiment of the application, the reference time information sent by the second network device includes information of the reference time and information of a reference point corresponding to the reference time, which is helpful for the terminal device to determine the reference time according to the reference point, thereby being helpful for the terminal device to accurately obtain the reference time.

With reference to the first aspect, in certain implementations of the first aspect, the first message includes information of a type of reference time, where the reference time information is reference time information corresponding to the type of reference time, and the method further includes: and the first network equipment receives a second message sent by the terminal equipment, wherein the second message is used for requesting the reference time information and comprises the information of the type of the reference time.

In the embodiment of the application, the first message carries the information of the type of the reference time, which is helpful for the second network device to acquire the type of the requested reference time, and the second network device can send the corresponding reference time information to the first network device according to the type of the reference time, which is helpful for saving signaling overhead of the second network device.

With reference to the first aspect, in certain implementations of the first aspect, the sending, by the first network device, the reference time information to the terminal device includes: the first network device sends a system message block SIB to the terminal device by unicast, wherein the SIB includes the reference time information.

In the embodiment of the application, when the first network device sends the reference time information to the terminal device, the reference time information may be carried in an SIB and sent to the terminal device in a unicast manner, which is helpful for the terminal device to know the reference time in a handover process, thereby helping to avoid an influence on service performance of the terminal device caused by a sending delay of the reference time.

With reference to the first aspect, in certain implementations of the first aspect, the sending, by the first network device to the terminal device, the reference time information includes first time information and second time information, and the sending, by the first network device, the reference time information includes: the first network device sends SIB to the terminal device by unicast, the SIB includes the first time information; and the first network device sending an RRC message to the terminal device, the RRC message including the second time information.

With reference to the first aspect, in some implementations of the first aspect, the RRC message is a downlink information transfer message.

In the embodiment of the application, when the first network device sends the reference time information to the terminal device, the first time information may be carried in an SIB and sent to the terminal device in a unicast manner; and carrying the second time information in an RRC message and sending the RRC message to the terminal equipment. Therefore, the influence of the sending delay of the reference time on the service performance of the terminal equipment is avoided, and meanwhile, the change on the standard is small.

In some possible implementations, the first time information is universal coordinated time (UTC) time information; the second time information is time information (e.g., 5G time) of the wireless network.

With reference to the first aspect, in certain implementations of the first aspect, the sending, by the first network device, the reference time information to the terminal device includes: the first network device transmits a SIB to the terminal device by broadcasting, the SIB including the reference time information.

In this embodiment of the application, when sending the reference time information to the terminal device, the first network device may carry the reference time information in an SIB and send the reference time information to the terminal device in a broadcast manner. When the reference time information is sent in a broadcast mode, the reference time information does not carry information of the reference point, and the terminal device can implicitly acquire the reference point corresponding to the reference time in the reference time information, so that the signaling overhead of the first network device is saved.

With reference to the first aspect, in some implementations of the first aspect, the response message is a handover request acknowledge message or a handover required acknowledge message.

In the embodiment of the application, the second network device may carry the reference time information in the handover request acknowledgement message or the handover requirement acknowledgement message sent to the first network device, which is helpful for saving signaling overhead of the second network device.

With reference to the first aspect, in some implementations of the first aspect, the response message is a handover request acknowledgement message, and the reference time information sent by the first network device to the terminal device is carried in the handover request acknowledgement message; or, the response message is a handover requirement acknowledgement message, and the reference time information sent by the first network device to the terminal device is carried in the handover requirement acknowledgement message.

In this embodiment, the first network device may directly transmit the handover request acknowledgement message or the handover requirement acknowledgement message of the second network device to the terminal device after receiving the handover request acknowledgement message or the handover requirement acknowledgement message. This may save the processing procedure of the handover request acknowledge message or the handover required acknowledge message by the first network device.

In a second aspect, a method for information transmission is provided, the method comprising: a first network device receives a first message sent by a second network device, wherein the first message is used for requesting to switch a terminal device from a first cell to a second cell, the first cell belongs to the second network device, and the second cell belongs to the first network device; the first network device sends a response message to the first message to the second network device, the response message including the reference time information.

With reference to the second aspect, in some implementations of the second aspect, the reference time information includes information of a reference time and information of a reference point corresponding to the reference time.

With reference to the second aspect, in some implementations of the second aspect, the first message includes information of a type of the reference time, and the reference time information is reference time information corresponding to the type of the reference time.

With reference to the second aspect, in some implementations of the second aspect, the response message is a handover request confirm message or a handover required confirm message.

In a third aspect, an information transmission method is provided, where the method includes: the centralized unit CU sends a first message to the distributed unit DU, the first message being used for requesting reference time information, the reference time information including UTC time information; the CU receives the reference time information sent by the DU.

In this embodiment, the CU may request the UTC time information from the DU, and the DU sends the reference time information including the UTC time information to the CU, so that the CU sends the reference time information to the terminal device. This enables the terminal device to acquire UTC time information.

With reference to the third aspect, in certain implementations of the third aspect, the first message further includes information of a type of the reference time, and the reference time information is reference time information corresponding to the type of the reference time.

In the embodiment of the application, the first message carries the information of the type of the reference time, which is helpful for the type of the reference time of the DU acquisition request, and the DU can send the corresponding reference time information to the CU according to the type of the reference time, which is helpful for saving the signaling overhead of the DU.

With reference to the third aspect, in certain implementations of the third aspect, the CU has a protocol layer function of at least one of a radio resource control protocol layer, a service data adaptation layer, and a packet data convergence protocol layer function; and/or the protocol layer function of the DU is at least one of a radio link control protocol layer, a medium access control layer and a physical layer function.

With reference to the third aspect, in certain implementations of the third aspect, the reference time information further includes time information of the wireless network.

With reference to the third aspect, in certain implementations of the third aspect, the first message further includes the first indication information and second indication information, where the first indication information is used to indicate that the DU sends the UTC time information to the CU according to a first cycle, or the first indication information is used to indicate that the DU sends the UTC time information to the CU after receiving a first request message sent by the CU; the second indication information is used to indicate that the DU sends the time information of the wireless network to the CU according to a second period, or the second indication information is used to indicate that the DU sends the time information of the wireless network to the CU after receiving a second request message sent by the CU.

In this embodiment of the present application, a CU may instruct a DU to send reference time information to the CU in different reporting manners, and for different types of reference time, the DU may report in different manners. This helps to increase the flexibility in reporting the reference time information by the DU.

With reference to the third aspect, in certain implementations of the third aspect, the first message further includes the first indication information, where the first indication information is used to instruct the DU to send the UTC time information and the time information of the wireless network to the CU according to a third period, or the first indication information is used to instruct the DU to send the UTC time information and the time information of the wireless network to the CU after receiving a third request message sent by the CU.

In this embodiment, the CU may instruct the DU to send the reference time information to the CU in a unified reporting manner.

In a fourth aspect, an information transmission method is provided, the method including: the distributed unit DU receives a first message sent by the centralized unit CU, wherein the first message is used for requesting reference time information, and the reference time information comprises UTC time information; the DU sends the reference time information to the CU.

In this embodiment, the CU may request the DU for the UTC time information, and the DU sends the CU reference time information including the UTC time information, so that the CU sends the reference time information to the terminal device. This enables the terminal device to acquire UTC time information.

With reference to the fourth aspect, in some implementations of the fourth aspect, the first message further includes information of a type of the reference time, and the reference time information is reference time information corresponding to the type of the reference time.

With reference to the fourth aspect, in some implementations of the fourth aspect, the CU has a protocol layer function of at least one of a radio resource control protocol layer, a service data adaptation layer, and a packet data convergence protocol layer function; and/or the protocol layer function of the DU is at least one of a radio link control protocol layer, a medium access control layer and a physical layer function.

In a fifth aspect, a method for information transmission is provided, the method comprising: the method comprises the steps that terminal equipment sends a first message to network equipment, wherein the first message is used for requesting a system message block SIB, and the SIB comprises reference time information; the terminal equipment receives the information of the reference time and the information of the reference point corresponding to the reference time, which are sent by the network equipment.

In the embodiment of the application, the terminal device can acquire the reference time sent by the network device and the information of the reference point corresponding to the reference time when requesting the SIB, which is helpful for the terminal device to accurately acquire the reference time according to the reference point.

With reference to the fifth aspect, in some implementations of the fifth aspect, the first message further includes information of the type of the reference time, and the reference time information is reference time information corresponding to the type of the reference time.

In the embodiment of the application, the first message carries the information of the type of the reference time, which is helpful for the network device to acquire the type of the requested reference time, and the network device can send the corresponding reference time information to the terminal device according to the type of the reference time, thereby being helpful for saving the signaling overhead of the network device.

With reference to the fifth aspect, in some implementations of the fifth aspect, the receiving, by the terminal device, the information about the reference time and the reference point corresponding to the reference time sent by the network device includes: the terminal device receives the SIB sent by the network device through unicast, where the SIB includes information of the reference time and information of a reference point corresponding to the reference time.

With reference to the fifth aspect, in some implementations of the fifth aspect, the information of the reference time includes first time information and second time information, and the receiving, by the terminal device, information of the reference time and a reference point corresponding to the reference time sent by the network device includes: the terminal device receives the SIB sent by the network device through unicast, wherein the SIB comprises information of the first time and information of a reference point corresponding to the first time; and the terminal equipment receives the RRC message sent by the network equipment, wherein the RRC message comprises the information of the second time and the information of the reference point corresponding to the second time.

With reference to the fifth aspect, in some implementations of the fifth aspect, the RRC message is a downlink information transfer message.

In the embodiment of the application, when the network device sends the reference time information to the terminal device, the first time information can be carried in an SIB and sent to the terminal device in a unicast manner; and carrying the second time information in an RRC message and sending the RRC message to the terminal equipment. Thus, the standard is less modified.

With reference to the fifth aspect, in some implementations of the fifth aspect, the receiving, by the terminal device, the information about the reference time and the reference point corresponding to the reference time sent by the network device includes: the terminal device receives the SIB sent by the network device through broadcasting, where the SIB includes the reference time and information of a reference point corresponding to the reference time.

In the embodiment of the present application, when the network device sends the reference time information to the terminal device, the reference time information may be carried in an SIB and sent to the terminal device in a broadcast manner. When the reference time information is sent in a broadcast mode, the reference time information does not carry information of the reference point, and the terminal equipment can implicitly acquire the reference point corresponding to the reference time in the reference time information, so that the signaling overhead of the network equipment is saved.

In a sixth aspect, there is provided an apparatus for information transmission, the apparatus comprising means for performing the steps of the above first to fourth aspects.

In a seventh aspect, there is provided an apparatus for information transmission, the apparatus comprising means or means (means) for performing the steps of the above fifth aspect or fifth aspect.

In an eighth aspect, an apparatus for information transmission is provided, the apparatus comprising at least one processor and a memory, the at least one processor being configured to perform the method provided in the first to fourth aspects above.

In a ninth aspect, there is provided an apparatus for information transmission, the apparatus comprising at least one processor and a memory, the at least one processor being configured to perform the method provided in the fifth aspect above.

A tenth aspect provides a terminal device, where the terminal device includes the apparatus provided in the seventh aspect, or the terminal includes the apparatus provided in the ninth aspect.

In an eleventh aspect, a network device is provided, where the terminal device includes the apparatus provided in the sixth aspect, or the terminal includes the apparatus provided in the eighth aspect.

In a twelfth aspect, a program is provided, which, when being executed by a processor, is adapted to carry out the method of any one of the first to fifth aspects.

In a thirteenth aspect, the present application provides a program product, such as a computer readable storage medium, comprising the program of the twelfth aspect.

Drawings

Fig. 1 is a schematic diagram of a communication system provided in an embodiment of the present application.

Fig. 2 is a schematic diagram of a network architecture according to an embodiment of the present application.

Fig. 3 is a schematic diagram of another network architecture provided in the embodiment of the present application.

Fig. 4 is a schematic flow chart of a process of a terminal device handing over from a source network device to a target network device.

Fig. 5 is a schematic flow chart of a method for information transmission provided by an embodiment of the present application.

Fig. 6 is a diagram illustrating the terminal device determining the reference time.

Fig. 7 is another schematic flow chart of a method for information transmission provided by an embodiment of the present application.

Fig. 8 is another schematic flow chart of a method for information transmission provided by an embodiment of the present application.

Fig. 9 is a schematic block diagram of an apparatus for information transmission provided by an embodiment of the present application.

Fig. 10 is another schematic block diagram of an apparatus for information transmission provided by an embodiment of the present application.

Fig. 11 is another schematic block diagram of an apparatus for information transmission provided by an embodiment of the present application.

Fig. 12 is another schematic block diagram of an apparatus for information transmission provided by an embodiment of the present application.

Fig. 13 is another schematic block diagram of an apparatus for information transmission provided by an embodiment of the present application.

Fig. 14 is a schematic structural diagram of a terminal device provided in an embodiment of the present application.

Fig. 15 is a schematic structural diagram of a network device provided in an embodiment of the present application.

Detailed Description

In the following, some terms in the present application will be explained:

1) a terminal, also called a User Equipment (UE), a Mobile Station (MS), or a Mobile Terminal (MT), is a device for providing voice/data connectivity to a user, such as a handheld device with a wireless connection function or a vehicle-mounted device. Currently, some examples of terminals are: a mobile phone (mobile phone), a tablet computer, a notebook computer, a palm top computer, a Mobile Internet Device (MID), a wearable device, a Virtual Reality (VR) device, an Augmented Reality (AR) device, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote surgery (remote medical supply), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety (smart security), a wireless terminal in city (smart city), a wireless terminal in smart home (smart home), and the like.

2) A network device is a device in a wireless network, such as a Radio Access Network (RAN) node that accesses a terminal to the wireless network. Currently, some examples of RAN nodes are: a gbb, a Transmission Reception Point (TRP), an evolved Node B (eNB), a Radio Network Controller (RNC), a Node B (NB), a Base Station Controller (BSC), a Base Transceiver Station (BTS), a home base station (e.g., home evolved Node B, or home Node B, HNB), a Base Band Unit (BBU), or a wireless fidelity (Wifi) Access Point (AP), etc. In one network configuration, a network device may include a Centralized Unit (CU) node, or a Distributed Unit (DU) node, or a RAN device including a CU node and a DU node.

The technical scheme of the embodiment of the 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 (long term evolution, LTE) system, a LTE Frequency Division Duplex (FDD) system, a LTE Time Division Duplex (TDD) system, a universal mobile telecommunications system (universal mobile telecommunications system, UMTS), a Worldwide Interoperability for Microwave Access (WiMAX) communication system, a 5G system, or a New Radio (NR) system, etc.

Before describing the embodiments of the present application, a few concepts related to the embodiments of the present application will be briefly described.

Coordinated universal time (coordinated universal time), also known as universal time, international coordinated time. Because English (CUT) and French (TUC) have different abbreviations, UTC is abbreviated as a compromise.

The coordinated universal time is a time metering system which is based on the length of atomic hour and second and is as close to the universal time as possible in time. The data element and exchange format information exchange date and time representation (GB/T7408-1994) of ISO 8601-1988 is called international coordinated time in China, and replaces the original GB/T7408-1994; taiwan adopts "information element and exchange format-information exchange-date and time representation" of CNS 7648, which is called universal time in the world. The accuracy of international atomic time is nanoseconds per day and the accuracy of world time is milliseconds per day. Many applications require a time system to be near Universal Time (UT). For this case, a trade-off time scale called coordinated universal time was introduced in 1972. To ensure that the world time is not different from the world time by more than 0.9 seconds, positive or negative leap seconds are added to the coordinated world time if necessary. Therefore, the difference of several integral seconds between the coordinated universal time and the international atomic time is accumulated year by year, and the time of the coordinated universal time is close to the time of the universal time by adopting a leap second method, and the difference is not more than 1 s. It not only maintains the uniformity of time scale, but also can approximately reflect the change of earth rotation. The maximum difference between UTC and UT1 (obtained by adding polar shift correction to UT) from 1/1972 can be up to ± 0.9s, according to the UTC amendment by the international council radio council (CCIR). The international terrestrial rotation central office in paris is responsible for deciding when to join leap seconds. Typically, the adjustment will be made during the last second of 6 months, 30 days and 12 months, 31 days each year.

Fig. 1 is a schematic diagram of a communication system 100 provided by an embodiment of the present application, and as shown in fig. 1, a terminal 130 accesses to a wireless network to obtain a service of an external network (e.g., the internet) through the wireless network, or communicates with other terminals through the wireless network. The wireless network includes a RAN110 and a Core Network (CN)120, where the RAN110 is used to access terminals 130 to the wireless network and the CN120 is used to manage the terminals and provide a gateway for communication with external networks.

It should be understood that the method of transmitting data provided herein may be applied to a wireless communication system, such as the wireless communication system 100 shown in fig. 1. Two communication devices in a wireless communication system have a wireless communication connection therebetween, and one of the two communication devices may correspond to the terminal 130 shown in fig. 1, and may be, for example, the terminal 130 in fig. 1, or may be a chip configured in the terminal 130; the other of the two communication devices may correspond to RAN110 shown in fig. 1, and may be RAN110 in fig. 1, or a chip configured in RAN110, for example.

Hereinafter, the embodiments of the present application will be described in detail by taking an interaction process between a terminal and a network device as an example without loss of generality. It is to be understood that any one terminal in a wireless communication system can communicate with one or more network devices having wireless communication connections based on the same method. This is not limited in this application.

It should be understood that for the communication system shown in fig. 1, the network device may be RAN110 in fig. 1 and the terminal may be terminal 130 in fig. 1.

Fig. 2 is a schematic diagram of a network architecture provided in an embodiment of the present application, and as shown in fig. 2, the network architecture includes a CN device and a RAN device. The RAN device includes a baseband device and a radio frequency device, where the baseband device may be implemented by one node or by multiple nodes, and the radio frequency device may be implemented independently by being pulled away from the baseband device, or integrated with the baseband device in the same physical device, or partially pulled away and partially integrated with the baseband device. For example, in an LTE communication system, an eNB as RAN equipment includes a baseband device and a radio frequency device, where the radio frequency device may be remotely arranged with respect to the baseband device, for example, a Remote Radio Unit (RRU) is remotely arranged with respect to a BBU.

The communication between the RAN equipment and the terminal follows a certain protocol layer structure. For example, the control plane protocol layer structure may include functions of protocol layers such as an RRC layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and a physical layer. The user plane protocol layer structure can comprise functions of protocol layers such as a PDCP layer, an RLC layer, an MAC layer, a physical layer and the like; in one implementation, a Service Data Adaptation Protocol (SDAP) layer may be further included above the PDCP layer.

The functions of these protocol layers may be implemented by one node, or may be implemented by a plurality of nodes; for example, in an evolved structure, a RAN device may include a Centralized Unit (CU) and a Distributed Unit (DU), and a plurality of DUs may be centrally controlled by one CU. As shown in fig. 3, the CU and the DU may be divided according to protocol layers of the radio network, for example, functions of a PDCP layer and above protocol layers are provided in the CU, and functions of protocol layers below the PDCP layer, for example, functions of an RLC layer and a MAC layer, are provided in the DU.

This division of the protocol layers is only an example, and it is also possible to divide the protocol layers at other protocol layers, for example, at the RLC layer, and the functions of the RLC layer and the protocol layers above are set in the CU, and the functions of the protocol layers below the RLC layer are set in the DU; alternatively, the functions are divided into some protocol layers, for example, a part of the functions of the RLC layer and the functions of the protocol layers above the RLC layer are provided in the CU, and the remaining functions of the RLC layer and the functions of the protocol layers below the RLC layer are provided in the DU. In addition, the processing time may be divided in other manners, for example, by time delay, a function that needs to satisfy the time delay requirement for processing is provided in the DU, and a function that does not need to satisfy the time delay requirement is provided in the CU.

In addition, the radio frequency device may be pulled away, not placed in the DU, or integrated in the DU, or partially pulled away and partially integrated in the DU, which is not limited herein.

Referring to fig. 3, fig. 3 is a schematic diagram illustrating another network architecture provided in the embodiment of the present application, and with respect to the architecture shown in fig. 2, the Control Plane (CP) and the User Plane (UP) of a CU may be separated and implemented by being divided into different entities, namely, a control plane CU entity (CU-CP entity) and a user plane CU entity (CU-UP entity), respectively.

In the above network architecture, the signaling generated by the CU may be sent to the terminal through the DU, or the signaling generated by the terminal may be received by the DU and then sent to the CU. The DU may pass through the protocol layer encapsulation directly to the terminal or CU without parsing the signaling. In the following embodiments, if transmission of such signaling between the CU and the terminal is involved, in this case, transmission or reception of signaling by the DU includes such a scenario. For example, the signaling of the RRC or PDCP layer is finally processed as data of the physical layer to be transmitted to the terminal or converted from the received data of the physical layer. Under this architecture, the signaling of the RRC or PDCP layer can be considered to be sent by the DU, or sent by the DU and the radio frequency.

In the above embodiment, the CU is divided into the network devices on the RAN side, and in addition, the CU may also be divided into the network devices on the CN side, which is not limited herein.

The apparatus in the following embodiments of the present application may be located in a terminal or a network device according to the functions implemented by the apparatus. When the above structure of CU-DU is adopted, the network device may be a CU node, or a DU node, or a network device including a CU node and a DU node.

Fig. 4 is a process for a terminal device to handover from a source network device to a target network device. In a conventional handover procedure of a mobile communication system, mobility management of a terminal device in a connected state is controlled by a network device, that is, the network device instructs the terminal device to which cell and how to perform handover by sending a handover message. As shown in fig. 4, specifically, after receiving the handover message, the terminal device accesses the target cell according to the content included in the handover message. Therefore, successful transmission of the handover message is a necessary condition to ensure successful handover under the conventional handover mechanism. The handover procedure includes:

s101, the source network equipment sends a first RRC reconfiguration message to the terminal equipment.

Optionally, the RRC reconfiguration message includes parameters such as a measurement object, a report configuration, and a measurement identifier.

And S102, after the terminal equipment measures according to the RRC reconfiguration message, the terminal equipment sends a measurement result to the source network equipment.

The terminal device may measure a series of cells according to the RRC reconfiguration message, and then form a report to report various events to the source network device, where the signal strength of the current serving cell is lower than the threshold and the signal strength of the target cell is higher than the threshold.

S103, the source network device determines whether the terminal device needs to be switched.

After receiving the report reported by the terminal device, the source base station determines that the terminal device needs not to switch, and if the source network device needs to be switched, the source base station sends a switching request message to the target network device.

And S104, if the source network equipment determines that the terminal equipment needs to be switched, the source network equipment sends a switching request to the target network equipment.

S105, the target network device determines not to allow the access of the terminal device according to the self connection number and other conditions, and if the access is allowed, the target network device sends a switching confirmation message to the source network device.

Optionally, the handover confirmation message includes parameters such as a new cell radio network temporary identifier (C-RNTI), a security-related algorithm of the target base station, and the like.

S106, the source network device sends a second RRC reconfiguration message (or, a handover command) to the terminal device.

After receiving the handover confirmation message sent by the target network device, the source network device sends a second RRC reconfiguration message (or a handover command) to the terminal device. Wherein the second RRC reconfiguration message contains the content from the handover confirm message of S105, which is transparent at the layer corresponding to the source network device. Specifically, the handover command in the NR system includes information about a target cell and related configuration parameters required by the terminal device to access the target cell, for example, the handover command includes information about the target cell (e.g., a Physical Cell Identifier (PCI) of the target cell and frequency information corresponding to the target cell (e.g., a frequency point corresponding to the target cell).

S107, the terminal device initiates random access to the target network device.

In the current handover procedure, the terminal device will disconnect from the source network device, and a short interruption will occur when the terminal device receives and transmits data before the terminal device successfully accesses the target network device. For ultra-reliable and low-latency communication (URLLC) traffic, if the URLLC traffic is still in progress during handover, the terminal device will receive information of the reference time (e.g., UTC time) from the target network device only after successfully accessing the target network device, so that the transmission delay of the reference time will cause a damage to the performance of the URLLC traffic. In the embodiment of the application, the target network device sends the information of the reference time in advance in the switching process, so that the influence of the sending delay of the reference time on the performance of the URLLC service in the switching process is reduced.

Fig. 5 shows a schematic flow chart of a method 200 for information transmission provided by an embodiment of the present application. As shown in fig. 5, the method 200 includes:

s201, a first network device sends a first message to a second network device, and the second network device receives the first message sent by the first network device, where the first message is used to request to switch a terminal device from a first cell to a second cell, where the first cell belongs to the first network device and the second cell belongs to the second network device.

Illustratively, the first network device may be the source network device in fig. 4, and the second network device may be the target network device in fig. 4.

Optionally, when an Xn interface exists between the first network device and the second network device, the first network device may initiate Xn handover, and the first message may be a handover request message (handover request), and the first network device directly sends the first message to the second network device.

Optionally, when an NG interface does not exist between the first network device and the second network device, the first network device may initiate an NG handover, and the first message may be a handover required message (handover required). The first network device may send a first message to the core network device, and the message a sent by the core network device to the second network device may be a message a (the message a may be the same as or different from the first message).

Illustratively, the first network device sends a handover request message to the core network device, and the core network device sends a handover request message (handover request) to the second network device.

Optionally, the first message includes, but is not limited to, one or more of the following information:

(1) the context information of the terminal device includes security capability information of the terminal device, such as encryption and integrity protection algorithms supported by the terminal device.

(2) Reference time request information for indicating that the second network device is requested to transmit reference time information.

Optionally, the reference time information includes at least one of the following information:

(2a) system Information Block (SIB) indication information for indicating SIB information requested by the terminal device. For example, can be the number of a SIB, such as SIB9, for instructing the terminal device to request the first network device to transmit SIB 9.

(2b) The type information of the reference time is used for indicating the type of the reference time requested by the terminal equipment, for example, the type of the reference time is UTC time, and is used for indicating the terminal equipment to request the second network equipment to send UTC time information; the time of the wireless network is used for indicating the terminal equipment to request the base station to send the time information of the wireless network; and the time of the wireless network and the UTC time are used for indicating the terminal equipment to request the second network equipment to send the UTC time and the time of the wireless network.

Optionally, the method 200 further comprises: and the terminal equipment sends a second message to the first network equipment, and the first network equipment receives the second message sent by the terminal equipment, wherein the second message comprises the information of the type of the reference time.

It should be understood that in the embodiments of the present application, the time of the wireless network may be the third generation partnership project (3)^rdgeneration partnership project, 3GPP), fifth generation mobile communication technology (5)^thgeneration mobile networks, 5G) time or 6G time, etc., for synchronization within a 5G or 6G system, respectively, e.g., 5G or 6GSynchronization between the network device and the terminal device of 6G is not limited in this embodiment.

(2c) The first period information is used to indicate a transmission period of SIB information requested by the terminal device, for example, in units of radio frames (radio frames) or system frames (system frames), or in units of milliseconds, minutes, slots (slots), and the like.

(2d) The second period information indicates a transmission period of the reference time information, for example, in units of a radio frame or a system frame, or in units of milliseconds, minutes, time slots, or the like.

(2e) The transmission mode information is used for indicating the transmission mode of the SIB information and/or the reference time information requested by the terminal device, for example, the transmission mode is unicast or broadcast, the transmission mode information may be a terminal device-oriented transmission mode and is transmitted to the first network device as the auxiliary information, and a specific transmission mode is subject to the decision of the first network device.

Optionally, before the first network device sends the first message to the second network device, the first network device receives the sent measurement result. The first network device determines to switch the first network device from the first cell to the second cell according to the measurement result.

S202, the second network device sends a response message to the first network device, and the first network device receives the response message from the second network device, where the response message includes the reference time information.

Optionally, when an Xn interface exists between the first network device and the second network device, the first network device may initiate Xn handover, and the response message may be a handover request acknowledge message (handover request acknowledge), and the response message is directly sent to the first network device by the second network device.

Alternatively, when there is no NG interface between the first network device and the second network device, the first network device may initiate an NG handover, and the response message may be a handover request acknowledge message (handover request acknowledge). The second network device may send the response message to the core network device, a message b sent by the core network device to the first network device (the message b may be the same as or different from the response message, but both include the reference time information).

For example, the second network device may send a handover request acknowledgement message to the core network device, and the core network device may send a handover requirement acknowledgement message (handover command) to the first network device.

Optionally, the reference time information includes information of a reference time (information of reference time) and information of a reference point corresponding to the reference time.

Illustratively, the reference time includes a UTC time, and the information of the UTC time includes, but is not limited to, one or more of the following:

(1) UTC time, for example, is on the order of 10 ms.

(2) And the reference point of the UTC time is used for indicating the reference point corresponding to the UTC time, namely the UTC time corresponding to the reference point is the UTC time.

It should be understood that, in this embodiment of the present application, the reference point may be a boundary of a time unit, and the time unit may be a slot (slot), a mini-slot (mini-slot), a slot after aggregation of multiple slots, a radio frame, or a system frame, and the present application is not limited thereto.

For example, the reference point may be a starting position or an ending position of a radio frame corresponding to a certain System Frame Number (SFN). The terminal device may determine the reference time by referring to a reference point of the time. As shown in fig. 6, the terminal device may receive the reference time information in a certain timeslot where SFN is x-3, where the reference time information includes information of the reference time and information of a reference point SFN is x, and then the terminal device may determine that a time corresponding to a system frame end position where SFN is x is the reference time.

(3) UTC time and local time offset.

(4) Global Positioning System (GPS) time and UTC time bias.

Illustratively, the reference time includes a time of the wireless network (hereinafter, the 5G time is taken as an example for explanation), and the information of the 5G time includes but is not limited to one or more of the following:

(1)5G time, for example, 10ns as a particle size.

(2) And the reference point of the 5G time is used for indicating the reference point corresponding to the 5G time, namely the 5G time corresponding to the reference point is the 5G time.

(3) A time type for indicating that the 5G time is a local clock or GPS time.

Illustratively, the reference time information may further include the information of the UTC time and the information of the 5G time described above.

S203, the first network device sends reference time information to the terminal device, and the terminal device receives the reference time information sent by the first network device.

Optionally, the sending, by the first network device, the reference time information to the terminal device includes: the first network device sends a system message block SIB to the terminal device by unicast, wherein the SIB comprises the reference time information.

For example, if the reference time information includes information of UTC time or time information of the wireless network, the SIB may include 2 information elements, where one information element may indicate the reference time and another information element may indicate a reference point corresponding to the reference information element.

For example, if the reference time information includes information of the UTC time and time information of the wireless network (e.g., information of 5G time), the SIB may include 4 information elements, where one information element may indicate the UTC time and another information element may indicate a reference point corresponding to the UTC time; one cell indicates the time of the wireless network and the other can indicate the reference point corresponding to the time of the wireless network.

Alternatively, the SIB may include 3 information elements, where one information element indicates the UTC time, another information element indicates the time of the wireless network, and another information element indicates the reference point corresponding to the UTC time and the time of the wireless network. That is, the reference point corresponding to the time of the wireless network may be used as the reference point corresponding to the UTC time.

Optionally, the first network device may also indicate the reference point of the UTC time in an implicit indication manner instead of carrying information of the reference point in the unicast SIB. For example, the first network device may broadcast a boundary of a System Information (SI) window in which an SIB of the UTC time is located as a reference point of the UTC time. In this case, the first network device is not required to carry the reference point of the UTC time when unicasting the SIB. When receiving the SIB transmitted by the first network device through unicast, the terminal device may use the boundary of the SI window as a reference point of the UTC time, thereby helping to save signaling overhead of the network device.

Optionally, the first network device may also send a first RRC message to the terminal device by unicast, where the first RRC message includes the reference time information.

Optionally, the first RRC message is RRC reconfiguration (RRC reconfiguration), RRC setup (RRC setup), RRC recovery (RRC resume), or downlink Information Transfer (DL Information Transfer), and the specific first RRC message is not limited herein.

Optionally, the reference time information includes first time information and second time information, and the sending, by the first network device, the reference time information to the terminal device includes: the first network device sends an SIB to the terminal device by unicast, where the SIB includes the first time information, and the first RRC message may include the SIB, for example, an Information Element (IE) used to send the SIB; and the first network device sending a second RRC message to the terminal device, the second RRC message including the second time information.

Optionally, the first time information is information of UTC time, and the second time information is time information of a wireless network.

Optionally, the second RRC message may be an RRC reconfiguration (RRC reconfiguration) message, an RRC setup (RRC setup) message, an RRC resume (RRC resume) message, or a downlink information transfer (DL information transfer) message, and the specific second RRC message is not limited herein.

In the embodiment of the present application, the first network device may carry the UTC time information in the first RRC message or the SIB included in the first RRC message, and carry the time information of the wireless network in the second RRC message, so that only one information element needs to be added in the SIB to indicate the reference point corresponding to the UTC time, which is less modified for the standard.

Optionally, the sending, by the first network device, the reference time information to the terminal device includes: the first network equipment sends SIB to the terminal equipment through broadcasting, and the SIB comprises reference time information.

It should be understood that, when the first network device sends the SIB to the terminal device through broadcasting, the reference time information in the SIB may not include information of the reference point corresponding to the reference time.

Since the first network device may transmit the SIB in the SI window when transmitting the SIB to the terminal device by broadcasting. Then, when receiving the SIB sent by the first network device through broadcasting, the terminal device may determine the reference point corresponding to the reference time through an SI window in which the SIB is located.

Optionally, the sending, by the first network device, the reference time information to the terminal device includes:

the first network equipment sends an RRC container (container) carried in a switching request confirmation message to the terminal equipment, wherein the RRC container carried in the switching request confirmation message comprises the reference time information; alternatively, the first and second electrodes may be,

the first network device sends an RRC container (container) carried in a handover requirement acknowledgement message to the terminal device, where the RRC container carried in the handover requirement acknowledgement message includes the reference time information.

After receiving the handover request acknowledgement message or the handover requirement acknowledgement message sent by the second network device, the first network device may pass through an RRC container in the handover request acknowledgement message or the handover requirement acknowledgement message to the terminal device.

In the embodiment of the application, the terminal device can request the reference time information from the network device in the handover preparation stage, so that the target network device sends the reference time information in advance, and the influence on the sending of the reference time information caused by the handover delay in the handover process is reduced.

Fig. 7 shows a schematic flow chart of a method 300 for information transmission provided by an embodiment of the present application. As shown in fig. 7, the method 300 includes:

s301, the terminal device sends a third message to the network device, and the network device receives the third message sent by the terminal device, wherein the third message is used for requesting the reference time.

Optionally, the third message may be an RRC message, which may be a dedicated system message request (dedicated SIB request) message, user equipment assistance information (UE assistance information), an RRC setup request (RRC setup request), an RRC recovery request (RRC resume request), and the like, and the RRC message is not limited in this embodiment.

Optionally, the third message may include, but is not limited to, one or more of the following:

(1) SIB indication information for indicating SIB information requested by the terminal device. For example, can be a SIB number, such as SIB9, for instructing the terminal device to request the network device to transmit SIB 9.

(2) And type information of the reference time, which is used for indicating the type of the reference time requested by the terminal equipment. For example UTC time and/or time of the wireless network.

One possible way is that the terminal device may display information carrying the type of the reference time in the third message. The type of reference time is indicated, for example, by some information element in the third message. For example, the information value of the type of the reference time may be one of the following manners: {1,2,3}. Wherein 1 represents that the terminal equipment requests UTC time; 2 represents the time when the terminal equipment requests the wireless network; and 3 represents a time when the terminal device requests the UTC time and the wireless network.

Another possibility is that the terminal device may indicate the type of the reference time by a certain information element in the third message when requesting only the UTC time or only the time of the wireless network. For example, the information value of the type of the reference time may be one of the following manners: {1,2}. Wherein 1 represents that the terminal equipment requests UTC time; and 2 represents the time when the terminal device requests the wireless network. If the terminal device does not indicate the type of the reference time by a certain information element in the third message, the terminal device implicitly indicates that it requests the UTC time and the time of the wireless network.

It should be understood that the above values are only illustrative, and the present application is not limited to this.

Another possible way is that the terminal device implicitly carries information of the type of the reference time. For example, different reference time information is requested through different third messages. For example, if the third message is a dedicated system message request message, the terminal implicitly indicates that it requests the UTC time; if the third message is the UE assistance information, the terminal device implicitly indicates that it requests the time of the wireless network. This eliminates the need for information indicating the type of reference time by some information element in the third message, which helps to save the signaling overhead of the terminal device.

(3) The first period information is used to indicate the transmission period of the SIB information requested by the terminal device, for example, in units of radio frames or system frames, or in units of milliseconds, minutes, slots, and the like.

(4) The second period information indicates a transmission period of the reference time information, for example, in units of a radio frame or a system frame, or in units of milliseconds, minutes, time slots, or the like.

(5) The transmission mode information is used for indicating the transmission mode of the SIB information and/or the reference time information requested by the terminal device, for example, the transmission mode information may be a transmission mode intended by the terminal device, and the specific transmission mode is subject to a network device decision.

S302, the network device sends a fourth message to the terminal device, and the terminal device receives the fourth message sent by the network device, wherein the fourth message includes reference time information.

Optionally, the reference time information includes information of a reference time and information of a reference point corresponding to the reference time.

It should be understood that, reference may be made to the description of the reference time information in S202 above for the information carried in the reference time information, and details are not described herein for brevity.

It should also be understood that, reference may be made to the description in S203 above for a manner in which the network device sends the fourth message to the terminal device, and details are not described herein for brevity.

In the prior art, only a terminal device supporting a connection state requests an SIB in an on-demand system information (OSI) manner, and a network device does not carry a reference point corresponding to UTC time when unicasting the SIB, so that the terminal device cannot accurately acquire the UTC time when receiving the SIB transmitted by the network device through unicasting. In this embodiment, the network device may carry the reference point corresponding to the UTC time in the fourth message, so that the terminal device may accurately acquire the UTC time in the SIB.

It should be understood that the method 300 may be combined with the method 200, for example, in S201, before the first network device sends the first message to the second network device, the first network device may receive the third message sent by the terminal device and send the fourth message to the terminal device, so that the terminal device may obtain the reference time information sent by the first network device. Subsequently, the terminal device may further acquire the reference time information transmitted by the second network device through S203.

Fig. 8 shows a schematic flow chart of a method 400 for information transmission provided by an embodiment of the present application. As shown in fig. 8, the method 400 includes:

s401, the centralized unit CU sends a fifth message to the distributed unit DU, and the DU receives the fifth message sent by the CU, where the fifth message is used to request reference time information, and the reference time information includes UTC time.

Alternatively, the fifth information may be a reference time information reporting control (reference time information reporting control) message, and may also be a message transmitted on any CU and DU interface, which is not limited herein.

Optionally, the fifth message includes one or more of the following information:

(1) reporting request types, including periodic reporting or on-demand reporting. For example, if the reporting request type is periodic reporting, a period value is included in the reporting request type to indicate a period size of the periodic reporting, for example, in units of radio frames. For example, if on-demand reporting is performed, the DU reports the reference time information to the CUs only after receiving the request of the CUs.

(2) Information of the type of the reference time for indicating the type of the reference time requested by the CU. For example, the type of the reference time is UTC time, which indicates that the type of the reference time that the CU requests the DU to transmit is UTC time; for example, the type of the reference time is the time of the wireless network, and is used for indicating that the type of the reference time for which the CU requests the DU to be sent is the time of the wireless network; for example, the type of the reference time is the UTC time and the time of the wireless network is used to indicate that the type of the reference time that the CU requests the DU transmission is the UTC time and the time of the wireless network.

One possible way is that the CU can display information carrying the type of reference time in this fifth message. The type of reference time is indicated, for example, by some information element in the fifth message. For example, the information value of the type of the reference time may be one of the following manners: {1,2,3}. Where 1 represents the CU requesting UTC time; 2 represents the time when the CU requests the wireless network; and 3 denotes the time the CU requests the UTC time and the wireless network.

Another possibility is that the CU may indicate the type of reference time by some information element in the fifth message when requesting only UTC time or only time of the wireless network. For example, the information value of the type of the reference time may be one of the following manners: {1,2}. Where 1 represents the CU requesting UTC time; and 2 represents the time when the CU requests the wireless network. If the CU does not indicate the type of reference time by some information element in the fifth message, the CU implicitly indicates that it requests the UTC time and the time of the wireless network.

Optionally, if the CU requests the DU for the UTC time and the time of the wireless network, the fifth message includes indication information i1 and indication information i2, where the indication information i1 is used to indicate that the DU sends the information of the UTC time to the CU according to the first cycle, or the indication information i1 is used to indicate that the DU sends the information of the UTC time to the CU after receiving the first request message sent by the CU;

the indication information i2 is used to indicate that the DU transmits time information of the wireless network to the CU according to the second period, or the indication information i2 is used to indicate that the DU transmits time information of the wireless network to the CU after receiving the second request message transmitted by the CU.

Optionally, if the CU requests the DU for the UTC time and the time of the wireless network, the fifth message includes indication information i3, where the indication information i3 is used to indicate that the DU sends information of the UTC time and the time information of the wireless network to the CU according to the third period, or the indication information i3 is used to indicate that the DU sends information of the UTC time and the time information of the wireless network to the CU after receiving the third request message sent by the CU.

Optionally, if the reference time information requested by the CU from the DU includes UTC time information, the fifth message may also be used to request one or more of the following information:

(1) daylight Saving Time (DST): the time is set up one hour faster by national regulations to save energy, and daylight savings are implemented in areas with higher latitudes, such as in the summer (usually starting from the day of summer) in europe, new zealand, canada, etc.

(2) Jump seconds difference (leap seconds): the time difference value used for indicating the GPS time and the UTC time, for example, after the terminal device receives the UTC time and the second-hop difference, the GPS time can be obtained according to the two pieces of information.

(3) Local time offset (LTC): the local time difference is used to indicate the difference between the local time and the UTC time, for example, after the terminal device receives the UTC time and the LTC, the local time can be obtained according to the two pieces of information.

S402, the DU sends a sixth message to the CU, and the CU receives the sixth message sent by the DU, wherein the sixth message comprises the reference time information.

Alternatively, the sixth information may be a reference time information report (reference time information report) message, and may also be a message transmitted on any CU and DU interface, which is not limited herein.

Alternatively, if the sixth message sent by the DU to the CU includes information of the UTC time and information of the wireless network time (taking 5G time as an example), the DU may indicate the reference point for the same time of the UTC time and the wireless network. UTC time may be included in the sixth message, e.g., at 10ms granularity; 5G time, e.g., 10ns as particle size; a reference point for indicating a reference point corresponding to the UTC time and the time of the wireless network; a time type to indicate whether the 5G time is local clock or GPS time.

Optionally, if the sixth message sent by the DU to the CU includes the information of the UTC time and the time information of the wireless network, wherein,

the information of the UTC time includes the UTC time, for example, with a granularity of 10 ms; the reference point corresponding to the UTC time is used for indicating the reference point corresponding to the UTC time, namely the UTC time corresponding to the reference point is the UTC time; offset of UTC time and local time; GPS time and UTC time.

The information of 5G time includes 5G time, for example, with granularity of 10 ns; a reference point corresponding to 5G time; a time type to indicate whether the 5G time is local clock or GPS time.

Currently, the DU can only report 5G time information, and the clock types of the UTC time and the 5G time information may be different, for example, when the clock type of the 5G time is a local clock, the CU cannot derive the UTC time according to the 5G time information, and thus cannot acquire accurate UTC time information. The embodiment adds the reporting process of the UTC time, so that the CU can acquire the UTC time and/or the 5G time.

It is understood that the method 400 described above may be combined with either the method 200 or the method 300. For example, when combined with the method 300, a CU may receive a fourth message from a terminal device requesting information of UTC time and information of 5G time. The CU can request information of UTC time and information of 5G time from the DU. After acquiring the information of the UTC time and the information of the 5G time from the DU, the CU may transmit the information of the UTC time and the information of the 5G time to the terminal device.

For another example, when combined with the method 200, a CU of a target network device receives a first message sent by a source network device requesting information of UTC time and information of 5G time. The CU of the target network device may request information of UTC time and information of 5G time from the DU of the target network device. After acquiring the information of the UTC time and the information of the 5G time, the CU of the target network device may send the information of the UTC time and the information of the 5G time to the source network device.

The method for information transmission according to the embodiment of the present application is described in detail above with reference to fig. 1 to 8, and the apparatus, the terminal device, and the network device for information transmission according to the embodiment of the present application are described in detail below with reference to fig. 9 to 15.

The embodiment of the application also provides a device for realizing any one of the methods. For example, there is provided an apparatus comprising means for performing each step performed by a terminal device in any of the above methods. For another example, another apparatus is also provided, which includes means for performing each step performed by a network device in any one of the above methods.

Fig. 9 shows a schematic block diagram of an apparatus 500 for information transmission provided in an embodiment of the present application, and as shown in fig. 9, the apparatus 500 for data transmission may include a first sending unit 510, a first receiving unit 520, and a second sending unit 530.

In a possible implementation manner, the information transmission apparatus 500 may be the first network device in the method 200, and may also be a chip configured in the first network device.

Specifically, the first sending unit 510 is configured to send a first message to a second network device, where the first message is used to request that a terminal device is handed over from a first cell to a second cell, where the first cell belongs to the apparatus 500, and the second cell belongs to the second network device;

a first receiving unit 520, configured to receive a response message to the first message from the second network device, where the response message includes reference time information;

a second sending unit 530, configured to send the reference time information to the terminal device.

It should be understood that the apparatus may transmit the first message to the second network device in a different manner from when the apparatus transmits the reference time information to the terminal device. For example, the apparatus may communicate the first message with a second network device by wire; the device can transmit the reference time information with the terminal equipment through an air interface.

Optionally, the first message includes information of a type of reference time, where the reference time information is reference time information corresponding to the type of reference time, and the apparatus further includes:

a second receiving unit, configured to receive a second message sent by the terminal device, where the second message is used to request the reference time information, and the second message includes information of the type of the reference time.

Optionally, the second sending unit 530 is specifically configured to:

and sending a system message block SIB to the terminal equipment through unicast, wherein the SIB comprises the reference time information.

Optionally, the reference time information includes first time information and second time information, and the second sending unit 530 is specifically configured to:

sending SIB to the terminal device by unicast, wherein the SIB includes the first time information; and

and sending an RRC message to the terminal equipment, wherein the RRC message comprises the second time information.

Optionally, the RRC message is a downlink information transfer message.

Optionally, the second sending unit 530 is specifically configured to:

and transmitting the SIB to the terminal device by broadcasting, the SIB including the reference time information.

Optionally, the response message is a handover request acknowledge message or a handover required acknowledge message.

Optionally, the response message is a handover request acknowledgement message, and the reference time information sent by the first network device to the terminal device is carried in the handover request acknowledgement message; or, the response message is a handover requirement acknowledgement message, and the reference time information sent by the first network device to the terminal device is carried in the handover requirement acknowledgement message.

Fig. 10 shows a schematic block diagram of an apparatus 600 for information transmission provided in an embodiment of the present application, and as shown in fig. 10, the apparatus 600 for information transmission may include a third receiving unit 610 and a third sending unit 620.

In a possible implementation manner, the information transmission apparatus 600 may be the second network device in the method 200, and may also be a chip configured in the second network device.

Specifically, the third receiving unit 610 is configured to receive a first message sent by a second network device, where the first message is used to request that a terminal device is switched from a first cell to a second cell, where the first cell belongs to the second network device, and the second cell belongs to the apparatus 600;

a third sending unit 620, configured to send a response message to the first message to the second network device, where the response message includes the reference time information.

Optionally, the first message includes information of a type of the reference time, and the reference time information is reference time information corresponding to the type of the reference time.

Fig. 11 shows a schematic block diagram of an apparatus 700 for information transmission provided in an embodiment of the present application, and as shown in fig. 11, the apparatus 700 for information transmission may include a fourth sending unit 710 and a fourth receiving unit 720.

In a possible implementation manner, the information transmission apparatus 700 may be the CU in the method 400, and may also be a chip configured in the CU.

Specifically, the fourth sending unit 710 sends a first message to the distributed unit DU, where the first message is used to request reference time information, and the reference time information includes UTC time information;

a fourth receiving unit 720, configured to receive the reference time information sent by the DU.

Optionally, the first message further includes information of a type of the reference time, and the reference time information is reference time information corresponding to the type of the reference time.

Optionally, the apparatus 700 has a protocol layer function of at least one of a radio resource control protocol layer, a service data adaptation layer, and a packet data convergence protocol layer; and/or

The protocol layer function of the DU is at least one of the functions of a radio link control protocol layer, a medium access control layer and a physical layer.

Optionally, the reference time information further includes time information of the wireless network.

Optionally, the first message further includes the first indication information and the second indication information, wherein,

the first indication information is used to indicate that the DU sends the UTC time information to the device 700 according to a first period, or the first indication information is used to indicate that the DU sends the UTC time information to the device 700 after receiving a first request message sent by the device 700;

the second indication information is used to indicate that the DU sends the time information of the wireless network to the device 700 according to a second period, or the second indication information is used to indicate that the DU sends the time information of the wireless network to the device 700 after receiving a second request message sent by the device 700.

Optionally, the first message further includes the first indication information, wherein,

the first indication information is used to indicate that the DU transmits the UTC time information and the time information of the wireless network to the device 700 according to a third period, or the first indication information is used to indicate that the DU transmits the UTC time information and the time information of the wireless network to the device 700 after receiving a third request message transmitted by the device 700.

Fig. 12 shows a schematic block diagram of an apparatus 800 for information transmission provided in an embodiment of the present application, and as shown in fig. 12, the apparatus 800 for information transmission may include a fifth receiving unit 810 and a fifth sending unit 820.

In a possible implementation manner, the information transmission apparatus 800 may be a DU in the method 400, or may be a chip configured in the DU.

Specifically, the fifth receiving unit 810 receives a first message sent by the centralized unit CU, the first message being for requesting reference time information, the reference time information including UTC time information;

a fifth sending unit 820, configured to send the reference time information to the CU.

Optionally, the CU has a protocol layer function of at least one of a radio resource control protocol layer, a service data adaptation layer, and a packet data convergence protocol layer; and/or the device 800 has a protocol layer function that is at least one of a radio link control protocol layer, a medium access control layer, and a physical layer function.

Fig. 13 shows a schematic block diagram of an apparatus 900 for information transmission provided in an embodiment of the present application, and as shown in fig. 13, the apparatus 900 for information transmission may include a sixth sending unit 910 and a sixth receiving unit 920.

In a possible implementation manner, the apparatus 900 for information transmission may be the terminal device in the methods 200 to 400, and may also be a chip configured in the terminal device.

A sixth sending unit 910, configured to send a first message to a network device, where the first message is used to request a system message block SIB, and the SIB includes reference time information;

a sixth receiving unit 920, configured to receive information of the reference time sent by the network device and information of a reference point corresponding to the reference time.

Optionally, the first message further includes information of the type of the reference time, and the reference time information is reference time information corresponding to the type of the reference time.

Optionally, the sixth receiving unit 920 is specifically configured to:

and receiving an SIB sent by the network equipment through unicast, wherein the SIB comprises information of the reference time and information of a reference point corresponding to the reference time.

Optionally, the information of the reference time includes first time information and second time information, and the sixth receiving unit 920 is specifically configured to:

receiving an SIB sent by the network device through unicast, wherein the SIB comprises information of the first time and information of a reference point corresponding to the first time; and

and receiving an RRC message sent by the network device, where the RRC message includes information of the second time and information of a reference point corresponding to the second time.

Optionally, the RRC message is a downlink information transfer message.

Optionally, the sixth receiving unit 920 is specifically configured to:

and receiving an SIB sent by the network equipment through broadcasting, wherein the SIB comprises the reference time and information of a reference point corresponding to the reference time.

It should be understood that the division of the units in the above devices is only a division of logical functions, and the actual implementation may be wholly or partially integrated into one physical entity or may be physically separated. And the units in the device can be realized in the form of software called by the processing element; or may be implemented entirely in hardware; part of the units can also be realized in the form of software called by a processing element, and part of the units can be realized in the form of hardware. For example, each unit may be a processing element separately set up, or may be implemented by being integrated into a chip of the apparatus, or may be stored in a memory in the form of a program, and a function of the unit may be called and executed by a processing element of the apparatus. In addition, all or part of the units can be integrated together or can be independently realized. The processing element described herein may in turn be a processor, which may be an integrated circuit having signal processing capabilities. In the implementation process, the steps of the method or the units above may be implemented by integrated logic circuits of hardware in a processor element or in a form called by software through the processor element.

In one example, the units in any of the above apparatuses may be one or more integrated circuits configured to implement the above methods, such as: one or more Application Specific Integrated Circuits (ASICs), or one or more microprocessors (DSPs), or one or more Field Programmable Gate Arrays (FPGAs), or a combination of at least two of these integrated circuit formats. As another example, when a unit in a device may be implemented in the form of a processing element scheduler, the processing element may be a general-purpose processor, such as a Central Processing Unit (CPU) or other processor capable of invoking programs. As another example, these units may be integrated together and implemented in the form of a system-on-a-chip (SOC).

The above unit for receiving is an interface circuit of the apparatus for receiving signals from other apparatuses. For example, when the device is implemented in the form of a chip, the receiving unit is an interface circuit for the chip to receive signals from other chips or devices. The above unit for transmitting is an interface circuit of the apparatus for transmitting a signal to other apparatuses. For example, when the device is implemented in the form of a chip, the transmitting unit is an interface circuit for the chip to transmit signals to other chips or devices.

Fig. 14 shows a schematic structural diagram of a terminal device provided in an embodiment of the present application. It may be the terminal device in the above embodiment, for implementing the operation of the terminal device in the above embodiment. As shown in fig. 14, the terminal device includes: an antenna 1010, a radio frequency part 1020, a signal processing part 1030. The antenna 1010 is connected to the radio frequency part 1020. In the downlink direction, the rf section 1020 receives information transmitted by the network device through the antenna 1010, and transmits the information transmitted by the network device to the signal processing section 1030 for processing. In the uplink direction, the signal processing part 1030 processes the information of the terminal device and sends the information to the radio frequency part 1020, and the radio frequency part 1020 processes the information of the terminal device and sends the information to the network device through the antenna 1010.

The signal processing section 1030 may include a modem subsystem for implementing processing of each communication protocol layer of data; the system also comprises a central processing subsystem used for realizing the processing of the operating system and the application layer of the terminal equipment; in addition, other subsystems, such as a multimedia subsystem for controlling a camera, a screen display, etc. of the terminal device, a peripheral subsystem for connecting with other devices, etc. may be included. The modem subsystem may be a separately provided chip. Alternatively, the above means for the terminal device may be located at the modem subsystem.

Modem subsystem may include one or more processing elements 1031, including, for example, a master CPU and other integrated circuits. The modem subsystem may also include a memory element 1032 and an interface circuit 1033. The storage element 1032 is used to store data and programs, but a program for executing the method executed by the terminal device in the above method may not be stored in the storage element 1032, but stored in a memory outside the modem subsystem, and the modem subsystem is loaded for use when used. The interface circuit 1033 is used to communicate with other subsystems. The above apparatus for a terminal device may be located in a modem subsystem, which may be implemented by a chip comprising at least one processing element for performing the steps of any of the methods performed by the above terminal device and interface circuitry for communicating with other apparatus. In one implementation, the unit for the terminal device to implement each step in the above method may be implemented in the form of a processing element scheduler, for example, an apparatus for the terminal device includes a processing element and a storage element, and the processing element calls a program stored in the storage element to execute the method executed by the terminal device in the above method embodiment. The memory elements may be memory elements with the processing elements on the same chip, i.e. on-chip memory elements.

In another implementation, the program for performing the method performed by the terminal device in the above method may be a memory element on a different chip than the processing element, i.e. an off-chip memory element. At this time, the processing element calls or loads a program from the off-chip storage element onto the on-chip storage element to call and execute the method executed by the terminal device in the above method embodiment.

In yet another implementation, the unit of the terminal device for implementing the steps of the above method may be configured as one or more processing elements disposed on the modem subsystem, where the processing elements may be integrated circuits, for example: one or more ASICs, or one or more DSPs, or one or more FPGAs, or a combination of these types of integrated circuits. These integrated circuits may be integrated together to form a chip.

The units of the terminal device for realizing the steps of the method can be integrated together and realized in the form of SOC, and the SOC chip is used for realizing the method. At least one processing element and a storage element can be integrated in the chip, and the processing element calls the stored program of the storage element to realize the method executed by the terminal equipment; or, at least one integrated circuit may be integrated in the chip, for implementing the method executed by the above terminal device; alternatively, the above implementation modes may be combined, the functions of the partial units are implemented in the form of a processing element calling program, and the functions of the partial units are implemented in the form of an integrated circuit.

It is seen that the above apparatus for a terminal device may comprise at least one processing element and interface circuitry, wherein the at least one processing element is configured to perform the method performed by any one of the terminal devices provided by the above method embodiments. The processing element may: namely, the method calls the program stored in the storage element to execute part or all of the steps executed by the terminal equipment; it is also possible to: that is, some or all of the steps performed by the terminal device are performed by integrated logic circuits of hardware in the processor element in combination with the instructions; of course, some or all of the steps performed by the terminal device may be performed in combination with the first manner and the second manner.

The processing elements herein, like those described above, may be a general purpose processor, such as a CPU, or one or more integrated circuits configured to implement the above methods, such as: one or more ASICs, or one or more microprocessors DSP, or one or more FPGAs, etc., or a combination of at least two of these integrated circuit forms.

The storage element may be a memory or a combination of a plurality of storage elements.

Fig. 15 is a schematic structural diagram of a network device according to an embodiment of the present application. For implementing the operations of the network devices (e.g., the first network device or the second network device in the method 200, the network device in the method 300, the CU or the DU in the method 400) in the above embodiments. As shown in fig. 15, the network device includes: antenna 1101, radio frequency device 1102, baseband device 1103. An antenna 1101 is connected to the radio frequency device 1102. In the uplink direction, the rf device 1102 receives information sent by the terminal device through the antenna 1101, and sends the information sent by the terminal device to the baseband device 1103 for processing. In the downlink direction, the baseband device 1103 processes the information of the terminal device and sends the information to the rf device 1102, and the rf device 1102 processes the information of the terminal device and sends the processed information to the terminal device through the antenna 1101.

The baseband device 1103 may include one or more processing elements 11031, including, for example, a host CPU and other integrated circuits. In addition, the baseband device 1103 may further include a storage element 11032 and an interface 11033, where the storage element 11032 is used to store programs and data; the interface 11033 is used for exchanging information with the rf device 1102, and is, for example, a Common Public Radio Interface (CPRI). The above means for a network device may be located on the baseband apparatus 1103, for example, the above means for a network device may be a chip on the baseband apparatus 1103, the chip comprising at least one processing element and interface circuitry, wherein the processing element is configured to perform the steps of any one of the methods performed by the above network device, and the interface circuitry is configured to communicate with other devices. In one implementation, the unit of the network device for implementing the steps in the above method may be implemented in the form of a processing element scheduler, for example, an apparatus for the network device includes a processing element and a storage element, and the processing element calls a program stored in the storage element to execute the method executed by the network device in the above method embodiment. The memory elements may be memory elements on the same chip as the processing element, i.e. on-chip memory elements, or may be memory elements on a different chip than the processing element, i.e. off-chip memory elements.

In another implementation, the unit of the network device for implementing the steps of the above method may be configured as one or more processing elements, which are disposed on the baseband apparatus, where the processing elements may be integrated circuits, for example: one or more ASICs, or one or more DSPs, or one or more FPGAs, or a combination of these types of integrated circuits. These integrated circuits may be integrated together to form a chip.

The units of the network device for implementing the steps of the above method may be integrated together and implemented in the form of an SOC, for example, the baseband device includes the SOC chip for implementing the above method. At least one processing element and a storage element can be integrated in the chip, and the method executed by the network equipment is realized in the form that the processing element calls the stored program of the storage element; or, at least one integrated circuit may be integrated in the chip, for implementing the method executed by the above network device; alternatively, the above implementation modes may be combined, the functions of the partial units are implemented in the form of a processing element calling program, and the functions of the partial units are implemented in the form of an integrated circuit.

It is seen that the above apparatus for a network device may comprise at least one processing element and interface circuitry, wherein the at least one processing element is configured to perform the method performed by any one of the network devices provided by the above method embodiments. The processing element may: namely, calling the program stored in the storage element to execute part or all of the steps executed by the network equipment; it is also possible to: that is, some or all of the steps performed by the network device are performed by integrated logic circuitry of hardware in the processor element in combination with the instructions; of course, some or all of the steps performed by the above network device may also be performed in combination with the first manner and the second manner.

The terminal device and the network device in the above-mentioned various apparatus embodiments may completely correspond to the terminal device or the network device in the method embodiment, and the corresponding module or unit performs the corresponding steps, for example, when the apparatus is implemented in the form of a chip, the receiving unit may be an interface circuit of the chip for receiving signals from other chips or apparatuses. The above unit for transmitting is an interface circuit of the apparatus for transmitting a signal to other apparatuses, for example, when the apparatus is implemented in the form of a chip, the transmitting unit is an interface circuit of the chip for transmitting a signal to other chips or apparatuses.

An embodiment of the present application further provides a communication system, including: the terminal device and/or the network device.

In the embodiment of the present application, it should be noted that the above method embodiments of the embodiment of the present application may be applied to a processor, or implemented by a processor. The processor may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method embodiments may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The processor described above may be a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware components. The various methods, steps, and logic blocks disclosed in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

It will be appreciated that the memory in the embodiments of the subject application can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. The non-volatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM), which acts as external cache memory. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), double data rate SDRAM, enhanced SDRAM, SLDRAM, Synchronous Link DRAM (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

The appearances of the phrases "first," "second," and the like in this application are only for purposes of distinguishing between different items and the phrases "first," "second," and the like do not by themselves limit the actual order or function of the items so modified. The appearances of the phrases "exemplary," e.g., "in an alternative design," or "in a design" in this application are only intended to serve as an example, illustration, or description. Any embodiment or design described herein as "exemplary," e.g., "optional design" or "one design" is not to be construed as preferred or advantageous over other embodiments or designs. Rather, use of these words is intended to present relevant concepts in a concrete fashion.

The terms "upstream" and "downstream" appearing in the present application are used to describe the direction of data/information transmission in a specific scenario, for example, the "upstream" direction generally refers to the direction of data/information transmission from the terminal device to the network side, or the direction of transmission from the distributed unit to the centralized unit, and the "downstream" direction generally refers to the direction of data/information transmission from the network side to the terminal device, or the direction of transmission from the centralized unit to the distributed unit.

Various objects such as various messages/information/devices/network elements/systems/devices/actions/operations/procedures/concepts may be named in the present application, it is to be understood that these specific names do not constitute limitations on related objects, and the named names may vary according to circumstances, contexts, or usage habits, and the understanding of the technical meaning of the technical terms in the present application should be mainly determined by the functions and technical effects embodied/performed in the technical solutions.

The structures of the CU and the DU in the embodiment of the present application are not limited to the 5G NR gbb, and may also be applied to a scenario in which an LTE base station is divided into the CU and the DU; a CU may be further divided into two parts, CP and UP. Optionally, when the LTE base station is used, the protocol layer does not include the SDAP layer.

Additionally, the terms "system" and "network" are often used interchangeably herein. The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

The network architecture and the service scenario described in the embodiment of the present application are for the convenience of readers to clearly understand the technical solution of the embodiment of the present application, and do not form a limitation on the technical solution provided in the embodiment of the present application, and it is known by a person of ordinary skill in the art that the technical solution provided in the embodiment of the present application is also applicable to similar technical problems along with the evolution of the network architecture and the appearance of a new service scenario.

The above embodiments may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product may include one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic disk), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An information transmission method, comprising:

a first network device sends a first message to a second network device, wherein the first message is used for requesting to switch a terminal device from a first cell to a second cell, the first cell belongs to the first network device, and the second cell belongs to the second network device;

the first network equipment receives a response message to the first message from the second network equipment, wherein the response message comprises reference time information;

and the first network equipment sends the reference time information to the terminal equipment.

2. The method according to claim 1, wherein the reference time information comprises information of a reference time and information of a reference point corresponding to the reference time.

3. The method according to claim 1 or 2, wherein the first message includes information of a type of reference time, and the reference time information is reference time information corresponding to the type of reference time, and the method further includes:

and the first network equipment receives a second message sent by the terminal equipment, wherein the second message is used for requesting the reference time information and comprises the information of the type of the reference time.

4. The method according to any one of claims 1 to 3, wherein the first network device sends the reference time information to the terminal device, and comprises:

and the first network equipment sends a system message block SIB to the terminal equipment through unicast, wherein the SIB comprises the reference time information.

5. The method according to any one of claims 1 to 3, wherein the reference time information comprises first time information and second time information, wherein the first network device transmits the reference time information to the terminal device, and wherein the method comprises:

the first network equipment sends SIB to the terminal equipment through unicast, wherein the SIB comprises the first time information; and

and the first network equipment sends an RRC message to the terminal equipment, wherein the RRC message comprises the second time information.

6. The method of claim 5, wherein the RRC message is a Downlink information transfer message.

7. The method according to any one of claims 1 to 3, wherein the first network device sends the reference time information to the terminal device, and comprises:

the first network equipment sends SIB to the terminal equipment through broadcasting, wherein the SIB comprises the reference time information.

8. The method according to any of claims 1 to 3, wherein the response message is a handover request acknowledge message or a handover required acknowledge message.

9. The method of claim 8,

the response message is a handover request confirmation message, and the reference time information sent by the first network device to the terminal device is carried in the handover request confirmation message; alternatively, the first and second electrodes may be,

the response message is a switching requirement confirmation message, and the reference time information sent by the first network device to the terminal device is carried in the switching requirement confirmation message.

10. A method of information transmission, comprising:

a first network device receives a first message sent by a second network device, wherein the first message is used for requesting to switch a terminal device from a first cell to a second cell, the first cell belongs to the second network device, and the second cell belongs to the first network device;

the first network device sends a response message to the first message to the second network device, wherein the response message comprises reference time information.

11. The method of claim 10, wherein the reference time information comprises information of a reference time and information of a reference point corresponding to the reference time.

12. The method according to claim 10 or 11, wherein the first message includes information of a type of the reference time, and the reference time information is reference time information corresponding to the type of the reference time.

13. The method according to any of claims 10 to 12, wherein the response message is a handover request acknowledge message or a handover required acknowledge message.

14. An information transmission method, comprising:

the method comprises the steps that a centralized unit CU sends a first message to a distributed unit DU, wherein the first message is used for requesting reference time information, and the reference time information comprises UTC time information;

and the CU receives the reference time information sent by the DU.

15. The method of claim 14, wherein the first message further includes information of a type of reference time, and wherein the reference time information is reference time information corresponding to the type of reference time.

16. The method according to claim 14 or 15, wherein the CU has a protocol layer function of at least one of radio resource control protocol layer, service data adaptation layer and packet data convergence protocol layer function; and/or

The protocol layer function of the DU is at least one of a radio link control protocol layer, a media access control layer and a physical layer function.

17. The method according to any of claims 14 to 16, wherein the reference time information further comprises time information of a wireless network.

18. The method of claim 17, further comprising the first indication information and second indication information in the first message, wherein,

the first indication information is used for indicating the DU to send the UTC time information to the CU according to a first period, or the first indication information is used for indicating the DU to send the UTC time information to the CU after receiving a first request message sent by the CU;

the second indication information is used to indicate the DU to send the time information of the wireless network to the CU according to a second period, or the second indication information is used to indicate the DU to send the time information of the wireless network to the CU after receiving a second request message sent by the CU.

19. The method of claim 17, further comprising the first indication information in the first message, wherein,

the first indication information is used to indicate the DU to send the UTC time information and the time information of the wireless network to the CU according to a third period, or the first indication information is used to indicate the DU to send the UTC time information and the time information of the wireless network to the CU after receiving a third request message sent by the CU.

20. An information transmission method, comprising:

the distributed unit DU receives a first message sent by a centralized unit CU, wherein the first message is used for requesting reference time information, and the reference time information comprises UTC time information;

the DU transmits the reference time information to the CU.

21. The method of claim 20, wherein the first message further includes information of a type of reference time, and wherein the reference time information is reference time information corresponding to the type of reference time.

22. The method according to claim 20 or 21, wherein the CU has a protocol layer function of at least one of radio resource control protocol layer, service data adaptation layer and packet data convergence protocol layer function; and/or

23. A method of information transmission, the method comprising:

a terminal device sends a first message to a network device, wherein the first message is used for requesting a system message block SIB, and the SIB comprises reference time information;

and the terminal equipment receives the information of the reference time sent by the network equipment and the information of the reference point corresponding to the reference time.

24. The method of claim 23, wherein the first message further includes information of a type of the reference time, and wherein the reference time information is reference time information corresponding to the type of the reference time.

25. The method according to claim 23 or 24, wherein the receiving, by the terminal device, the information about the reference time and the reference point corresponding to the reference time sent by the network device comprises:

and the terminal equipment receives the SIB sent by the network equipment through unicast, wherein the SIB comprises the information of the reference time and the information of the reference point corresponding to the reference time.

26. The method according to claim 23 or 24, wherein the information of the reference time includes first time information and second time information, and the receiving, by the terminal device, information of the reference time and a reference point corresponding to the reference time sent by the network device includes:

the terminal equipment receives the SIB sent by the network equipment through unicast, wherein the SIB comprises the information of the first time and the information of a reference point corresponding to the first time; and

and the terminal equipment receives an RRC message sent by the network equipment, wherein the RRC message comprises the information of the second time and the information of the reference point corresponding to the second time.

27. The method of claim 26, wherein the RRC message is a downlink information transfer message.

28. The method according to claim 23 or 24, wherein the receiving, by the terminal device, the information about the reference time and the reference point corresponding to the reference time sent by the network device comprises:

and the terminal equipment receives the SIB sent by the network equipment through broadcasting, wherein the SIB comprises the reference time and information of a reference point corresponding to the reference time.

29. An apparatus for information transmission, comprising means for performing the steps of the method according to any one of claims 1-22.

30. An apparatus for information transmission, comprising means for performing the steps of the method according to any one of claims 23-28.

31. An apparatus for information transmission, comprising at least one processor configured to perform the method of any one of claims 1-22 and an interface circuit.

32. An apparatus for information transmission, comprising at least one processor configured to perform the method of any one of claims 23-28 and an interface circuit.

33. A terminal device, characterized in that it comprises the apparatus according to claim 30 or 32.

34. A network device comprising an apparatus according to claim 29 or 31.

35. A readable storage medium, comprising a program or instructions for performing the method of any one of claims 1-28 when the program or instructions are run on a computer.

36. A computer program comprising a program or instructions for performing the method of any one of claims 1 to 28 when the program or instructions are run on a computer.