WO2022016473A1 - 一种用于接入回传一体化iab系统中的通信方法和通信装置 - Google Patents

一种用于接入回传一体化iab系统中的通信方法和通信装置 Download PDF

Info

Publication number
WO2022016473A1
WO2022016473A1 PCT/CN2020/103893 CN2020103893W WO2022016473A1 WO 2022016473 A1 WO2022016473 A1 WO 2022016473A1 CN 2020103893 W CN2020103893 W CN 2020103893W WO 2022016473 A1 WO2022016473 A1 WO 2022016473A1
Authority
WO
WIPO (PCT)
Prior art keywords
node
network device
access network
rrc reconfiguration
indication information
Prior art date
Application number
PCT/CN2020/103893
Other languages
English (en)
French (fr)
Inventor
朱元萍
刘菁
罗海燕
史玉龙
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to KR1020237005378A priority Critical patent/KR20230041037A/ko
Priority to AU2020459888A priority patent/AU2020459888B2/en
Priority to BR112023001182A priority patent/BR112023001182A2/pt
Priority to PCT/CN2020/103893 priority patent/WO2022016473A1/zh
Priority to CN202080105148.5A priority patent/CN116097745A/zh
Priority to CA3189789A priority patent/CA3189789A1/en
Priority to JP2023504426A priority patent/JP2023534851A/ja
Priority to EP20945967.6A priority patent/EP4185005A4/en
Publication of WO2022016473A1 publication Critical patent/WO2022016473A1/zh
Priority to US18/156,560 priority patent/US20230156848A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/20—Manipulation of established connections
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0055—Transmission or use of information for re-establishing the radio link
    • H04W36/0072—Transmission or use of information for re-establishing the radio link of resource information of target access point
    • H04W36/00725—Random access channel [RACH]-less handover
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/24—Reselection being triggered by specific parameters
    • H04W36/249—Reselection being triggered by specific parameters according to timing information
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access
    • H04W74/08—Non-scheduled access, e.g. ALOHA
    • H04W74/0833—Random access procedures, e.g. with 4-step access
    • H04W74/0841—Random access procedures, e.g. with 4-step access with collision treatment
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0055—Transmission or use of information for re-establishing the radio link
    • H04W36/0066—Transmission or use of information for re-establishing the radio link of control information between different types of networks in order to establish a new radio link in the target network
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access
    • H04W74/08—Non-scheduled access, e.g. ALOHA
    • H04W74/0833—Random access procedures, e.g. with 4-step access
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/02—Terminal devices
    • H04W88/04—Terminal devices adapted for relaying to or from another terminal or user
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/08—Access point devices

Definitions

  • the present application relates to the field of wireless communication technologies, and in particular, to a communication method and communication device used in an integrated IAB system for access and backhaul.
  • the fifth-generation (5G) mobile communication puts forward more stringent requirements in all aspects for various network performance indicators.
  • the capacity index has increased by 1000 times, wider coverage requirements, ultra-high reliability and ultra-low latency, etc.
  • the integrated access and backhaul (IAB) system came into being. Through a large number of densely deployed nodes, it can provide flexible and convenient access and backhaul services for terminals, improve coverage, and meet the stricter requirements of 5G. harsh performance indicators.
  • relay nodes may be switched due to link quality and other reasons.
  • the switching of relay nodes will affect other nodes or terminals in the IAB system, resulting in interruption of service transmission, which greatly affects the Degraded user experience.
  • the present application provides a communication method, a communication device and a communication system applied to an integrated IAB system for access and backhaul, which can make the sub-node stop the timer in time during the random access-free process of the sub-node to avoid
  • the timeout of the timer leads to handover failure, which improves the success rate of handover, reduces the delay of handover, and guarantees the performance of handover.
  • a first aspect of the present application provides a communication method applied to an integrated IAB system for access and backhaul.
  • the method may be performed by the child node, or may be performed by a chip in the child node.
  • the following is an example of sub-node execution.
  • the method includes: the child node receives, through the parent node, a first radio resource control RRC reconfiguration message from an access network device, where the first RRC reconfiguration message includes an indication of free random access; the child node receives the first RRC reconfiguration After the message, start the timer; then the child node sends the first RRC reconfiguration complete message to the access network device through the parent node; the child node receives the first indication information from the parent node, the first indication information indicates to stop the timer; The node stops the timer according to the first indication information.
  • the child node can stop the timer in time to avoid handover failure and cell reselection caused by timer timeout, reduce the handover delay, and ensure the communication performance after the handover.
  • the first indication information may instruct to stop the timer in an explicit or implicit manner. Two ways of hinting are described below.
  • the first indication information is the first type of medium access control element MAC CE, and the sub-node stops the timer by default after receiving the first type of MAC CE.
  • the first indication information is a MAC CE carrying a contention resolution identifier
  • the contention resolution identifier may be the C-RNTI of the child node, or may be the value of one or more bits (bits) in the C-RNTI , or the competition resolution identifier may be any numerical value, which is not limited in this application.
  • the child node may stop the timer after parsing out the MAC CE carrying the contention resolution identifier.
  • the cell radio network temporary identifier C-RNTI before the sub-node receives the first RRC reconfiguration message, and the cell radio network temporary identifier C-RNTI after receiving the first RRC reconfiguration message can be the same.
  • the first RRC reconfiguration message does not include the cell radio network temporary identity of the child node.
  • the first RRC reconfiguration message includes second indication information, and the second indication information indicates that the cell radio network temporary identity of the sub-node remains unchanged.
  • the first RRC reconfiguration message includes the cell radio network temporary identifier used before the sub-node receives the first RRC reconfiguration message.
  • the method may further include: the parent node receives third indication information from the access network device; then, in response to the third indication information, the parent node sends the first indication information to the child node.
  • the third indication information includes the identifier of the child node. Since the parent node may have multiple child nodes, it is convenient for the parent node to know which child node to send the first indication information to by including the identifiers of the child nodes in the third indication information.
  • the access network device is the target access network device of the child node and the parent node in the group switching process.
  • a group in performing group switching includes at least a child node and a parent node, and the group may also include one or more other nodes.
  • the child node is always connected to the parent node, that is, the parent node of the child node does not change.
  • the method further includes: after the parent node receives the first RRC reconfiguration message from the access network device or sends the first RRC reconfiguration message to the child node, the parent node receives the second RRC reconfiguration message from the access network device, And the parent node starts the timer.
  • the parent node may switch, thereby stopping the transmission with the access network device, and the parent node first receives the first RRC reconfiguration message from the access network device or sends the first RRC reconfiguration message to the child node. configuration message, the parent node then receives the second RRC reconfiguration message, which can ensure that the parent node sends the first RRC reconfiguration message to the child node, and ensures the switching performance of the child node.
  • the method may further include: after the parent node receives the first RRC reconfiguration message from the access network device or sends the first RRC reconfiguration message to the child node, the parent node sends fourth indication information to the source access network device to trigger the source access network device.
  • the network access device sends the second RRC reconfiguration message to the parent node, and the source access network device is the source access network device of the child node and the parent node in the group switching process.
  • the second RRC reconfiguration message may be sent by the target access network device to the source access network device first, and then sent by the source access network device to the parent node, and the parent node sends the fourth indication to the source access network device. information, it can be ensured that after the parent node receives the first RRC reconfiguration message from the access network device or sends the first RRC reconfiguration message to the child node, the parent node receives the second RRC reconfiguration message again.
  • the child node is a terminal or an IAB node
  • the parent node is an IAB node
  • the access network device may include a CU, and optionally, the access network device may further include a DU.
  • a second aspect of the present application provides a communication method applied to an integrated IAB system for access and backhaul.
  • the method may be performed by the parent node, or may be performed by a chip in the parent node.
  • the following takes the execution of the parent node as an example to introduce.
  • the method includes: the parent node receives a first RRC reconfiguration message from an access network device, the first RRC reconfiguration message includes an indication of free random access; the parent node sends the first RRC reconfiguration message to the child node to trigger the child node The node starts a timer; the parent node receives the first RRC reconfiguration complete message from the child node; the parent node sends the first RRC reconfiguration complete message to the access network device; the parent node sends first indication information to the child node, the first indication information Indicates to stop the timer.
  • the method further includes: the parent node receives second indication information from the access network device; and in response to the second indication information, the parent node sends the first indication information to the child node.
  • the second indication information includes the identifier of the child node.
  • the first indication information is a first type of medium access control element MAC CE, or the first indication information is a MAC CE carrying a contention resolution identifier.
  • the cell radio network temporary identifier C-RNTI before the sub-node receives the first RRC reconfiguration message, and the cell radio network temporary identifier C-RNTI after receiving the first RRC reconfiguration message can be the same.
  • the first RRC reconfiguration message does not include the cell radio network temporary identity of the child node.
  • the first RRC reconfiguration message includes third indication information, where the third indication information indicates that the cell radio network temporary identity of the sub-node remains unchanged.
  • the first RRC reconfiguration message includes the cell radio network temporary identifier of the child node before the parent node sends the first RRC reconfiguration message to the child node.
  • the access network device is the target access network device of the sub-node during the group handover process.
  • the method further includes: after the parent node receives the first RRC reconfiguration message from the access network device or sends the first RRC reconfiguration message to the child node, the parent node receives the second RRC reconfiguration message from the access network device, and The parent node starts the timer.
  • the method further includes: after the parent node receives the first RRC reconfiguration message from the access network device or sends the first RRC reconfiguration message to the child node, the parent node sends fourth indication information to the source access network device to trigger the source access network device The device sends a second RRC reconfiguration message to the parent node, and the source access network device is the source access network device of the child node and the parent node in the group switching process.
  • the child node is a terminal or an IAB node
  • the parent node is an IAB node
  • the access network device may include a CU, and optionally, the access network device may further include a DU.
  • a third aspect of the present application provides a communication method applied to an integrated IAB system for access and backhaul.
  • the method may be performed by an access network device, or may be performed by a chip in the access network device.
  • the following takes the implementation of the access network device as an example for introduction.
  • the method includes: an access network device sends a first radio resource control RRC reconfiguration message to a child node through a parent node, so as to trigger the child node to start a timer, the first RRC reconfiguration message includes an indication of free random access;
  • the network device receives the first RRC reconfiguration complete message from the child node through the parent node;
  • the access network device sends the second indication information to the parent node to trigger the parent node to send the first indication information to the child node, and the first indication information indicates to stop the timing device.
  • the second indication information includes the identifier of the child node.
  • the first indication information is a first type of medium access control element MAC CE, or the first indication information is a MAC CE carrying a contention resolution identifier.
  • the cell radio network temporary identifier C-RNTI before the sub-node receives the first RRC reconfiguration message, and the cell radio network temporary identifier C-RNTI after receiving the first RRC reconfiguration message can be the same.
  • the first RRC reconfiguration message does not include the cell radio network temporary identity of the child node.
  • the first RRC reconfiguration message includes third indication information, where the third indication information indicates that the cell radio network temporary identity of the sub-node remains unchanged.
  • the first RRC reconfiguration message includes the cell radio network temporary identifier of the child node before the access network device sends the first RRC reconfiguration complete message to the child node through the parent node.
  • the access network device is the target access network device of the sub-node during the group handover process.
  • the method further includes: the target access network device receives a handover request message from the source access network device, where the handover request message includes one or more of the following: the cell radio network temporary identifier of the child node before the handover, the child node before the handover The identity of the accessed cell and the hierarchical information of the child node in the network topology, and the source access network device is the source access network device of the child node and the parent node in the group handover process.
  • the method further includes: the target access network device determines the duration of the timer according to the level information; wherein the first RRC reconfiguration message includes information of the duration of the timer.
  • the target access network device receives the level information of the child node in the network topology, and the target access network device can reasonably determine the duration of the timer according to the level information, such as the number of hops of the wireless backhaul link with the migrated IAB node.
  • the level information such as the number of hops of the wireless backhaul link with the migrated IAB node.
  • the present application provides a communication method applied in an integrated IAB system for access and backhaul, which can keep the C-RNTI before and after the handover of the child node unchanged, reduce the process of configuring the C-RNTI on the child node, and reduce the function of the child node. consumption, save power.
  • a fourth aspect of the present application provides a communication method applied to an integrated IAB system for access and backhaul.
  • the method may be performed by the child node, or may be performed by a chip in the child node.
  • the following is an example of sub-node execution.
  • the method includes: a child node receives a first radio resource control RRC reconfiguration message from an access network device through a parent node; the child node performs handover according to the first RRC reconfiguration message; wherein the cell radio network temporary identifier before the child node handover is the same as The temporary identifiers of the cell wireless networks after the handover are the same.
  • the process of configuring the C-RNTI of the sub-node can be reduced, the power consumption of the sub-node can be reduced, and the power of the sub-node can be saved.
  • the cell radio network temporary identifier C-RNTI before the sub-node receives the first RRC reconfiguration message, and the cell radio network temporary identifier C-RNTI after receiving the first RRC reconfiguration message can be the same.
  • the first RRC reconfiguration message does not include the cell radio network temporary identity of the child node, or the first RRC reconfiguration message includes first indication information, and the first indication information indicates that the cell radio network temporary identity of the child node remains unchanged, Or the first RRC reconfiguration message includes the cell radio network temporary identifier used before the sub-node receives the first RRC reconfiguration message.
  • the first RRC reconfiguration message includes an indication of free random access.
  • the method of the fourth aspect may further include the method of the first aspect, and for details, please refer to the content of the first method.
  • the method further includes: the child node starts a timer; the child node sends a first RRC reconfiguration complete message to the access network device through the parent node; the child node receives second indication information from the parent node, and the second indication information indicates to stop the timer ; The child node stops the timer.
  • the child node is a terminal or an IAB node
  • the parent node is an IAB node
  • the access network device may include a CU, and optionally, the access network device may further include a DU.
  • a fifth aspect of the present application provides a communication method applied to an integrated IAB system for access and backhaul.
  • the method may be performed by an access network device, or may be performed by a chip in the access network device.
  • the following takes the implementation of the access network device as an example for introduction.
  • the method includes: the access network device obtains the first RRC reconfiguration message; the access network device sends the first RRC reconfiguration message to the child node through the parent node; wherein, the first RRC reconfiguration message is used for the child node's
  • the temporary identification of the cell wireless network before the handover of the child node is the same as the temporary identification of the cell wireless network after the handover.
  • the cell radio network temporary identifier C-RNTI before the sub-node receives the first RRC reconfiguration message, and the cell radio network temporary identifier C-RNTI after receiving the first RRC reconfiguration message can be the same.
  • the first RRC reconfiguration message does not include the cell radio network temporary identity of the child node, or the first RRC reconfiguration message includes first indication information, and the first indication information indicates that the cell radio network temporary identity of the child node remains unchanged, Or the first RRC reconfiguration message includes the cell radio network temporary identifier used before the sub-node receives the first RRC reconfiguration message.
  • the first RRC reconfiguration message includes an indication of free random access.
  • the method of the fifth aspect may further include the method of the third aspect, and for details, reference may be made to the method of the third aspect.
  • the method of the fifth aspect may further include: the access network device receives the first RRC reconfiguration complete message from the child node through the parent node; the access network device sends the second indication information to the parent node to trigger the parent node to send the child node to the child node. Send third indication information, where the third indication information instructs to stop the timer.
  • the present application provides a solution, which can ensure that the parent node receives the RRC reconfiguration message of the child node first, and then receives the RRC reconfiguration message of the parent node during the group switching process, so as to avoid the parent node from receiving its own RRC reconfiguration message first. After the RRC reconfiguration message, the transmission with the source access network device will be stopped, so that the RRC reconfiguration message of the sub-node cannot be received, and the handover function of the sub-node is guaranteed.
  • a sixth aspect of the present application provides a communication method applied to an integrated IAB system for access and backhaul.
  • the method can be performed by the parent node, or by a chip in the parent node.
  • the following takes the execution of the parent node as an example to introduce.
  • the method includes: after the parent node receives the first RRC reconfiguration message from the source access network device or sends the first RRC reconfiguration message to the child node, the parent node receives the second RRC reconfiguration message from the source access network device.
  • the first RRC reconfiguration message is used to trigger the child node to start the timer
  • the second RRC reconfiguration message is used to trigger the parent node to start the timer
  • the source access network device may be the source access network device of the child node and the parent node in the group switching process.
  • the group for group switching may include one or more other nodes.
  • the method further includes: after the parent node receives the first RRC reconfiguration message from the source access network device or sends the first RRC reconfiguration message to the child node, the parent node sends the first indication information to the source access network device, In response to the first indication information, the source access network device sends a first RRC reconfiguration message to the parent node.
  • the method of the sixth aspect may include the content of the method of the second aspect.
  • the content of the method in the second aspect refer to the content of the method in the second aspect.
  • a seventh aspect of the present application provides a communication method applied to an integrated IAB system for access and backhaul.
  • the method may be performed by the source access network device, or by a chip in the source access network device.
  • the following takes the source access network device behavior as an example for introduction.
  • the method includes: after the source access network device sends the first RRC reconfiguration message to the parent node, the source access network device sends the second RRC reconfiguration message to the parent node.
  • the first RRC reconfiguration message is used for the handover or RRC reconfiguration of the parent node, which may be referred to as the RRC reconfiguration message of the parent node
  • the second RRC reconfiguration message is used for the handover of the child node Or reconfiguration, which may be referred to as a child node's RRC reconfiguration message.
  • the first RRC reconfiguration message is used to trigger the child node to start the timer
  • the second RRC reconfiguration message is used to trigger the parent node to start the timer
  • the source access network device may be the source access network device of the child node and the parent node in the group switching process.
  • the group for group switching may include one or more other nodes.
  • the method further includes: after the source access network device sends the first RRC reconfiguration message to the parent node, the source access network device receives the first indication information from the parent node, and responds to the first indication information, the source access network device sends the second RRC reconfiguration message to the parent node.
  • the source access network device can use the C-RNTI of one or more nodes in the group to perform group handover, and the cell identifier of the accessed cell. And/or level information in the network topology is sent to the target access network device.
  • An eighth aspect of the present application provides a communication method applied to an integrated IAB system for access and backhaul.
  • the method may be performed by the source access network device, or by a chip in the source access network device.
  • the following takes the execution of the source access network device as an example for introduction.
  • the method includes: a source access network device obtains a handover request message, and the source access network device sends a handover request message to a target access network device, including the C-RNTI of one or more nodes, the cell identifier of the accessed cell and/or or hierarchical information in the network topology.
  • the source access network device sends the C-RNTI of one or more nodes to the target access network device, so that the target access network device can carry the C-RNTI of each node in the RRC reconfiguration message and send it to the node.
  • the C-RNTI of the node can remain unchanged before and after the handover, which reduces the process of configuring the C-RNTI and reduces the power consumption of the node.
  • the source access network device can facilitate the target access network device to uniquely identify the one or more nodes.
  • the cell identifier of the accessed cell may include a physical cell identifier (physical cell identifier, PCI), an NR cell identifier (NR Cell Identity, NCI), an NR cell global identifier (NR cell global identifier, NCGI), E - One or more of UTRAN cell global identifiers (E-UTRAN cell global identifiers, ECGI).
  • PCI physical cell identifier
  • NCI NR Cell Identity
  • NR cell global identifier NR cell global identifier
  • E-UTRAN cell global identifiers E-UTRAN cell global identifiers
  • the PCI of the cell before and after the handover may remain unchanged, and the NCGI and ECGI may be changed.
  • the source access network device sends information about the level of one or more nodes in the network topology to the target access network device, so that the target access network device can reasonably determine the duration of the timer according to the level information.
  • a node with a larger number of hops on the wireless backhaul link between nodes has a longer timer duration, and a node with a smaller number of hops on the wireless backhaul link with the migrating IAB node has a smaller timer duration. . Avoid the situation that the child node switching fails due to the unreasonable setting of the timer duration.
  • the source access network device is the source access network device of the one or more nodes in the group handover process
  • the target access network device is the one or more nodes in the group Target access network device during group handover.
  • the level information of the one or more nodes in the network topology is used to determine the information of the duration of the timers of the one or more nodes.
  • the method further includes: the source access network device receives the respective RRC reconfiguration messages of the one or more nodes from the target access network device, and the source access network device sends the one or more RRC reconfiguration messages to the one or more nodes.
  • Each of the nodes sends an RRC reconfiguration message of the node, and the RRC reconfiguration message of each node includes information on the duration of the timer at that point. It can be understood that sending the RRC reconfiguration message of the node to each node by the source access network device may specifically include that the source access network device first sends the RRC reconfiguration message of the node to the parent node of the node, and then the parent node sends the RRC reconfiguration message to the node. Send the RRC reconfiguration message.
  • the method of the eighth aspect may further include the method of the seventh aspect. It can be understood that the child node and the parent node of the seventh aspect may be one or more nodes in the method of the eighth aspect.
  • a ninth aspect of the present application provides a communication method applied to an integrated IAB system for access and backhaul.
  • the method may be performed by the target access network device, or by a chip in the target access network device.
  • the following takes the execution of the target access network device as an example for introduction.
  • the method includes: the target access network device receives a handover request message from the source access network device, including the C-RNTI of one or more nodes, the cell identity of the accessed cell, and/or level information in the network topology.
  • the source access network device is the source access network device of the one or more nodes in the group handover process
  • the target access network device is the one or more nodes in the group Target access network device during group handover.
  • the target access network device determines duration information of respective timers of one or more nodes according to the level information.
  • the method further includes: the target access network device acquires the respective RRC reconfiguration messages of one or more nodes, and the target access network device sends the one or more nodes to the source access network device The respective RRC reconfiguration message, the source access network device sends the RRC reconfiguration message of the node to each of the one or more nodes, and the RRC reconfiguration message of each node includes the duration of the timer of the node. information.
  • the method of the ninth aspect may further include the method of the third aspect, which will not be described herein again.
  • the method further includes: the target access network device receives the RRC reconfiguration message of each node, and after receiving the RRC reconfiguration message of each node, the target access network device sends indication information to the parent node of the node to trigger the The parent node instructs the node to stop the timer.
  • the method of the ninth aspect may further include the method of the fifth aspect, which will not be described herein again.
  • the cell radio network temporary identity of each node before and after handover remains unchanged.
  • a tenth aspect of the present application provides a communication method applied to an integrated IAB system for access and backhaul.
  • the method may be performed by the target access network device, or by a chip in the target access network device.
  • the following takes the execution of the target access network device as an example for introduction.
  • the method includes: the target access network device obtains a group handover command, and the group handover command includes one or more of the following: indication information of free random access, the duration of the handover timer and the public configuration information of the serving cell.
  • the target access network device broadcasts a group switching command.
  • the target access network device is the target access network device in the group handover process.
  • the group performing group switching may include one or more nodes, and correspondingly, the one or more nodes may acquire the group switching command.
  • the signaling overhead of the air interface can be saved.
  • the signaling overhead caused by individually sending signaling to multiple nodes in the group can be avoided by the above-mentioned broadcasting method.
  • the method of the tenth aspect may further include the methods of the third aspect, the fifth aspect and/or the ninth aspect, which will not be described herein again.
  • An eleventh aspect of the present application provides a communication method, which can be applied to a single air interface scenario.
  • the terminal switches from a source access network device to a target access network device, where the target access network device includes a CU and a DU, and the method may include: the CU sends first indication information to the DU, so as to trigger the DU to send second indication information to the terminal, The terminal stops the timer according to the second indication information.
  • the method may further include: the target CU sends the first RRC reconfiguration message to the terminal through the source access network device, and the terminal receives the first RRC reconfiguration message.
  • the configuration message starts a timer, the terminal sends the first RRC reconfiguration complete message to the DU, and the DU sends the first RRC reconfiguration complete message to the CU.
  • the first indication information in the eleventh aspect may refer to the content of the second indication information in the first aspect
  • the second indication information in the eleventh aspect may refer to the content of the first indication information in the first aspect.
  • the content will not be described here.
  • One or more of the methods in the above-mentioned first to eleventh aspects may be combined with each other, and in the method of each aspect, one or more of the various possible implementations may be combined with each other.
  • a twelfth aspect of an embodiment of the present application provides a communication device, where the communication device may be a child node or a chip in a child node, or the communication device may be a parent node or a chip in the parent node, or the communication device may be The source access network device or the chip in the source access network device, or the communication device may be the target access network device or the chip in the target access network device, or the communication device may be the CU or the chip in the CU, or The communication means may be a DU or a chip in a DU.
  • the communication device includes a processor for executing a computer program or instructions to cause the communication device to perform the methods of the first to eleventh aspects.
  • the communication device further includes the memory.
  • the processor is coupled to a memory for storing computer programs or instructions, the processor for executing the computer programs or instructions in the memory.
  • the communication apparatus may further include a communication unit, and the communication unit is configured to communicate with other devices or other components in the communication apparatus.
  • the communication device is a child node or a parent node, and the communication unit is a transceiver.
  • the communication device is an access network device, and the communication unit may include an interface between a transceiver and the access network device, where the transceiver is used for the access network device to communicate with a sub-node of the access network device, and the interface is used to communicate with the access network device.
  • Communication between access network equipment and other access network equipment is a CU, and the communication unit is an interface between the CU and the DU, and an interface between the CU and other access network devices.
  • the communication device is a DU, the communication unit is an interface between the CU and the DU, and the transceiver of the DU.
  • the communication unit is an input/output circuit or interface of the chip.
  • a ninth aspect of the embodiments of the present application provides a communication device, the communication device has a child node, a parent node, a source access network device, a target access network device, a source access network device, or a target access network device for implementing the above method aspects
  • the function of the behavior of the CU of the network device, the source access network device, or the DU of the target access network device which includes components for performing the steps or functions described in the method aspects of the first to eleventh aspects above. (means).
  • the steps or functions can be implemented by software, or by hardware, or by a combination of hardware and software.
  • a thirteenth aspect of an embodiment of the present application provides a chip, the chip includes a processor and an interface circuit, the interface circuit is coupled to the processor, and the processor is configured to run a computer program or instructions to implement the first to the first aspect
  • the interface circuit is configured to communicate with other modules other than the chip.
  • a fourteenth aspect of the embodiments of the present application provides a computer storage medium storing a program for implementing the method in any one of the foregoing first aspect to the eleventh aspect.
  • the wireless communication device is caused to perform the method of any one of the first to eleventh aspects.
  • a fifteenth aspect of the embodiments of the present application provides a computer program product, the program product includes a program, when the program is executed, the method of any one of the first to seventh aspects above is executed.
  • a sixteenth aspect of the embodiments of the present application provides a communication system, including one of a child node, a parent node, a source access network device, and a target access network device involved in the methods of the first aspect to the eleventh aspect, or multiple.
  • FIG. 1 is a schematic diagram of a mobile communication system 100 provided by an embodiment of the present application.
  • FIG. 2 is a schematic diagram of a separation architecture of a CU-DU provided by an embodiment of the present application
  • IAB integrated access and backhaul node
  • 4A is a schematic diagram of a control plane protocol stack of a single air interface provided by an embodiment of the present application.
  • 4B is a schematic diagram of a user plane protocol stack of a single air interface provided by an embodiment of the present application.
  • 5A is a schematic diagram of a control plane protocol stack in an IAB network provided by an embodiment of the present application.
  • 5B is a schematic diagram of a user plane protocol stack in an IAB network provided by an embodiment of the present application.
  • FIG. 6 is a schematic diagram of group switching provided by an embodiment of the present application.
  • Fig. 7 is a kind of communication method provided by the implementation of the present application.
  • FIG. 9 is another communication method provided by an embodiment of the present application.
  • FIG. 10 is a schematic structural diagram of a terminal provided by an embodiment of the present application.
  • FIG. 11 is a schematic structural diagram of an access network device provided by an embodiment of the present application.
  • FIG. 12 is a schematic structural diagram of a communication device provided by an embodiment of the present application.
  • FIG. 13 is a schematic structural diagram of a communication device according to an embodiment of the present application.
  • FIG. 1 is a schematic structural diagram of a communication system 100 provided by an embodiment of the present application.
  • the communication system 100 includes at least one terminal (eg, terminal 110 , terminal 120 and terminal 130 ), at least one relay node 140 (relay node, RN), at least one access network device 150 and at least one core network device 160 .
  • the terminal may be connected to at least one access network device, or the terminal may be connected to at least one access network device through at least one relay node, and the at least one access network device is connected to at least one core network device.
  • both the terminal 110 and the terminal 120 are connected to the relay node 140
  • the relay node 140 is connected to the access network device 150
  • the terminal 130 is connected to the access network device 150 .
  • the access network device 150 is connected to the core network device 160 .
  • the connection mode between the terminal 110, the terminal 120, the terminal 130, the relay node 140, the access network device 150, and the core network device 160 may be wireless or wired, which is not limited in this application.
  • the communication system provided by this application may be, for example, a long term evolution (LTE) system supporting 4G access technology, a new radio (NR) system supporting 5G access technology, any system related to the 3rd Generation Partnership Project ( 3rd generation partnership project, 3GPP) related cellular systems, wireless-fidelity (WiFi) systems, worldwide interoperability for microwave access (WiMAX) systems, multiple radio access technologies (Radio Access Technology, RAT) system, or other future-oriented communication technologies.
  • LTE long term evolution
  • NR new radio
  • 5G access technology any system related to the 3rd Generation Partnership Project ( 3rd generation partnership project, 3GPP) related cellular systems, wireless-fidelity (WiFi) systems, worldwide interoperability for microwave access (WiMAX) systems, multiple radio access technologies (Radio Access Technology, RAT) system, or other future-oriented communication technologies.
  • 3rd Generation Partnership Project 3rd generation partnership project, 3GPP
  • WiFi wireless-fidelity
  • WiMAX worldwide interoperability for microwave access
  • the terminal in this application is a device with wireless transceiver function, which can be deployed on land, including indoor or outdoor, handheld, wearable or vehicle-mounted; it can also be deployed on water (such as ships, etc.); it can also be deployed in the air (such as unmanned aircraft, planes, balloons and satellites, etc.).
  • the terminal can be a mobile phone (mobile phone), a tablet computer (Pad), a computer with a wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, an industrial control (industrial control) wireless terminals in self-driving, wireless terminals in remote medical, wireless terminals in smart grid, wireless terminals in transportation safety, Wireless terminals in smart cities, wireless terminals in smart homes, and so on.
  • a terminal may also sometimes be referred to as terminal equipment, user equipment (UE), access terminal equipment, station, UE unit, UE station, mobile station, mobile station, remote station, remote terminal equipment, mobile equipment, UE terminal equipment , terminal device, wireless communication device, UE proxy or UE device, or some other suitable term.
  • Terminals can also be stationary or mobile.
  • the access network device may be a device on the access network side used to support terminal access to the communication system, and the access network device may be called a base station (base station, BS), for example, an evolved base station in a 4G access technology communication system ( evolved nodeB (eNB), next generation nodeB (gNB), transmission reception point (TRP), relay node (relay node), access point (access point, etc.) in the 5G access technology communication system AP), access nodes in WiFi systems, wireless backhaul nodes, etc., or access network devices can be called host nodes, IAB donors (IAB donor), host IAB, host or host gNB (DgNB, donor gNB), etc. .
  • IAB donors IAB donor
  • DgNB host or host gNB
  • the base station can be: a macro base station, a micro base station, a pico base station, a small base station, a relay station, and the like. Multiple base stations may support the above-mentioned networks of the same technology, or may support the above-mentioned networks of different technologies.
  • a base station may include one or more co-sited or non-co-sited transmission receiving points (TRPs).
  • the access network device may also be a wireless controller, a central unit (central unit, CU), and/or a distributed unit (distributed unit, DU) in a cloud radio access network (cloud radio access network, CRAN) scenario.
  • the access network device may also be a server, a wearable device, or a vehicle-mounted device.
  • the multiple access network devices in the communication system may be base stations of the same type, or may be base stations of different types.
  • the base station can communicate with the terminal, and can also communicate with the terminal device through the relay station.
  • the terminal can communicate with multiple base stations of different technologies.
  • the terminal can communicate with the base station supporting the LTE network, and can also communicate with the base station supporting the 5G network, and can also support dual connection with the base station of the LTE network and the base station of the 5G network. .
  • the core network device can be connected to one or more access network devices, and can provide one or more functions of session management, access authentication, Internet Protocol (IP) address allocation, and data transmission for the terminals in the system.
  • the core network equipment may be a mobile management entity (MME) or a serving gateway (SGW) in the 4G access technology communication system, and the access and mobility management functions in the 5G access technology communication system ( Access and Mobility Management Function, AMF) network element or user plane performance (User Plane Function, UPF) network element and so on.
  • AMF Access and Mobility Management Function
  • UPF User Plane Function
  • a relay node may be a node that provides wireless access services and/or backhaul services.
  • the wireless access service refers to the provision of data and/or signaling through the wireless access link
  • the wireless backhaul service refers to the data and/or signaling backhaul service provided through the wireless backhaul link.
  • the relay node is used to realize the forwarding of data and/or signaling between the terminal and the access network device.
  • the relay node provides wireless access services for the terminal through an access link (AL), and on the other hand, it is connected to the access network equipment through a one-hop or multi-hop backhaul link (BL).
  • AL access link
  • BL one-hop or multi-hop backhaul link
  • the relay node may have different names in different communication systems, for example, the relay node may be called a wireless backhaul node or a wireless backhaul device.
  • a relay node can be called an integrated access and backhaul node (IAB node).
  • IAB node integrated access and backhaul node
  • the relay node may also have different names, which is not limited here.
  • the relay node may also act as a terminal device.
  • the relay node may also be a CPE in a home access scenario.
  • the IAB node may be a device such as customer premises equipment (customer premises equipment, CPE) or a residential gateway (residential gateway, RG).
  • CPE customer premises equipment
  • RG residential gateway
  • the method provided by the embodiment of the present application may also be applied to a scenario of home access (home access).
  • FIG. 2 is a schematic diagram of a separation architecture of a CU-DU provided by an embodiment of the present application.
  • the access network device 150 in FIG. 1 may adopt a CU-DU separation architecture, and FIG. 2 takes the access network device as a gNB (new radio nodeB, gNB) as an example for description.
  • gNB new radio nodeB
  • the gNB can be implemented through the cloud radio access network (C-RAN) architecture. Part of the functions of the gNB are implemented by the central unit (CU), and another part of the functions are implemented by the distributed unit (DU). .
  • the segmentation of CU and DU can be divided according to the protocol stack.
  • One possible way is to aggregate the radio resource control (RRC) layer, service data adaptation protocol (SDAP) layer and packet data.
  • the protocol (packet data convergence protocol, PDCP) layer is deployed in the CU, and the rest of the radio link control (radio link control, RLC) layer, media access control (media access control, MAC) layer and physical (physical, PHY) layer is deployed in DU.
  • One CU can be connected to one DU or multiple DUs, which facilitates network expansion.
  • the CU and the DU are connected through an interface (such as the F1 interface), and the CU and the core network (such as a 5G core network (5G core network, 5GC)) are connected through an interface (such as an NG interface).
  • an interface such as the F1 interface
  • the CU and the core network such as a 5G core network (5G core network, 5GC)
  • 5G core network 5G core network, 5GC
  • the CU includes a user plane (User plane, UP for short) (abbreviated as CU-UP in this application) and a control plane (Control plane, CP for short) (abbreviated as CU-CP in this application).
  • User plane UP for short
  • Control plane CP for short
  • FIG. 3 is a schematic diagram of an integrated access and backhaul node (IAB) network provided by an embodiment of the present application.
  • FIG. 3 is an application scenario of the communication system 100 shown in FIG. 1 .
  • the terminal, the relay node and the access network device in FIG. 1 are further described below with reference to FIG. 3 .
  • the IAB network includes one or more terminals (for clarity, only terminal 1 is shown in FIG. 3 ), one or more IAB nodes (for clarity, two IAB nodes are shown in FIG. 2 , namely IAB node 1 and IAB node 2), and one or more host nodes (for clarity, only IAB donor 1 is shown in Figure 2).
  • the terminal 1 can be connected with one or more IAB nodes, each IAB node can be connected with one or more other IAB nodes, and one or more IAB nodes can be connected with one or more host nodes.
  • one or more IAB nodes may also be connected to each other, which is not limited in this application.
  • the IAB donor may be called a donor node (donor node), a DgNB (that is, a donor gNodeB) or other suitable names, which are not limited in this application.
  • the terminal 1 may be the terminal 110 in FIG. 1 .
  • IAB node 1 and IAB node 2 may be relay nodes 140 in FIG. 1 .
  • the IAB donor 1 may be the access network device 150 in FIG. 1 .
  • the 5G core network (5G Core Network, 5GC) and the evolved packet core (evolved packet core, EPC) may be composed of at least one core network device in FIG. 1 . core network.
  • the IAB donor 1 in Fig. 3 can be the gNB in Fig. 2, and the IAB donor 1 can adopt the CU-DU separation architecture in Fig. 2, that is, the IAB donor 1 can be composed of a centralized unit (which can be called the IAB donor CU 1 ) and distribution unit (can be called IAB donor DU 1), IAB donor CU 1 can be composed of CP (can be called IAB donor CU 1-CP) and UP (can be called IAB donor CU 1-UP), specifically Refer to the content in Figure 2.
  • CP can be called IAB donor CU 1-CP
  • UP can be called IAB donor CU 1-UP
  • the IAB network supports an independent networking (standalone, SA) or a non-standalone (non-standalone, NSA) networking mode.
  • SA independent networking
  • non-standalone non-standalone
  • the IAB donor 1 can be connected to the 5GC.
  • the IAB donor CU 1-CP can be connected to the control plane network elements in the 5GC, such as access and mobility management functions (access and mobility management functions).
  • the mobility management function, AMF is connected, and the IAB donor CU 1-UP can be connected to the user plane network elements in the 5GC, such as the user plane function (user plane function, UPF).
  • IAB donor 1 as a secondary gNB (secondary gNB, SgNB), establishes dual connections with the primary eNB (master eNB, MeNB).
  • the IAB donor CU 1-CP is connected to the MeNB, the MeNB is connected to the EPC, and the IAB donor CU 1-UP is connected to a network element in the EPC, such as a service gateway (serving gateway, SGW).
  • SGW service gateway
  • a transmission path between the terminal and the host node may include one or more IAB nodes. If an IAB node is a node accessed by a terminal, the link between the IAB node and a sub-node (ie, a terminal) may be called an access link. If an IAB node is a node that provides backhaul services for terminals under other IAB nodes, the link between the IAB node and its child nodes (that is, other IAB nodes) can be called a backhaul link.
  • terminal 1 is connected to IAB node 1 through a wireless access link
  • IAB node 1 is connected to IAB node 2 through a wireless backhaul link
  • IAB node 2 is connected to IAB donor 1 through a wireless backhaul link .
  • the IAB network supports multi-hop IAB node and multi-connection IAB node networking.
  • On a path there is a definite hierarchical relationship between IAB nodes, as well as between IAB nodes and the host node serving the IAB node, and each IAB node or terminal will provide access services for the IAB node or terminal as a parent node. . Accordingly, each IAB node or terminal can be regarded as a child node of its parent node.
  • the parent node of the parent node of the IAB node is called the grandparent node of the IAB node, and the child nodes of the child node of the IAB node are regarded as the grandchild nodes of the IAB node.
  • the parent node and the child node are relative concepts, and a certain node can be a child node relative to one node, and can be a parent node relative to another node.
  • IAB node 1 is the parent node of terminal 1, and terminal 1 is the child node of IAB node 1
  • IAB node 2 is the parent node of IAB node 1
  • IAB node 1 is the child node of IAB node 2
  • IAB donor 1 (specifically can be IAB donor DU) is the parent node of IAB node 2
  • IAB node 2 is the child node of IAB donor 1 (specifically can be IAB donor DU).
  • the uplink data packets of the terminal can be transmitted to the host node through one or more IAB nodes, and then sent by the host node to the core network device, such as a mobile gateway device (such as the user plane function (UPF) in the 5G network). network element).
  • the core network device such as a mobile gateway device (such as the user plane function (UPF) in the 5G network). network element).
  • the downlink data packet of the terminal will be received by the host node from the mobile gateway device of the core network device, and then sent to the terminal through one or more IAB nodes.
  • the transmission path of the uplink data packet between terminal 1 and IAB donor 1 is: terminal 1 ⁇ IAB node 1 ⁇ IAB node 2 ⁇ IAB donor 1, and the downlink data packet between terminal 1 and IAB donor 1
  • the transmission path is: IAB donor 1 ⁇ IAB node 2 ⁇ IAB node 1 ⁇ terminal 1.
  • an IAB node accessed by a terminal may be referred to as an access IAB node, and other IAB nodes on the transmission path may be referred to as intermediate IAB nodes.
  • the intermediate IAB node can provide backhaul services for the terminal.
  • An IAB node can be used as an access IAB node for a terminal, or as an intermediate IAB node for other terminals.
  • IAB node 1 is an access IAB node
  • IAB node 2 is an intermediate IAB node
  • terminal 2 accesses IAB node 3 (not shown in Figure 3)
  • IAB node 3 accesses IAB node 1
  • IAB node 1 is the intermediate IAB node.
  • one or more IAB nodes and one or more terminals served by an IAB node may be referred to as descendant nodes of the IAB node.
  • the descendant nodes may include the IAB nodes served by the IAB node, Or it can be understood that descendant nodes include subordinate IAB nodes that are connected to the IAB node through at least one hop link, for example descendant nodes include child nodes and grandchild nodes, etc., and terminals that access these IAB nodes include, for example, access child nodes. and grandchild nodes etc.
  • the descendant nodes of IAB node 2 include terminal 1 and IAB node 1.
  • the above-mentioned IAB network is only an example.
  • the IAB network combining multi-hop and multi-connection, there are more other possibilities for the IAB network.
  • the host node and the IAB node under another host node form dual connections as terminals. Services, etc., will not be listed here.
  • an IAB node when the IAB node acts as a parent node, it can act as a similar access network device to provide access services to its child nodes. For example, its child nodes can be allocated for transmission through scheduling. Uplink resources for uplink data.
  • an IAB node When an IAB node is a child node, it can act as a terminal device for the parent node that provides services for the IAB node, for example, through cell selection, random access and other operations, establish a connection with the parent node, and obtain the parent node to schedule it The uplink resources used to transmit uplink data.
  • the functional unit in the IAB node that supports the IAB node to realize the role of the terminal device is referred to as the mobile terminal (mobile terminal, MT) functional unit of the IAB node, and is referred to as IAB-MT or IAB-UE for short.
  • the functional unit in the IAB node that supports the IAB node to realize the role of the access network device is called the DU functional unit of the IAB node, and is referred to as IAB-DU for short.
  • IAB-MT and IAB-DU can be a logical functional unit whose functions are implemented by IAB nodes; or IAB-MT and IAB-DU can be a physical division, and IAB-MT and IAB-DU can be IAB nodes different physical devices in .
  • IAB node 1 includes MT functional unit and DU functional unit
  • IAB node 2 includes MT functional unit and DU functional unit.
  • FIG. 4A and FIG. 4B are respectively a schematic diagram of a control plane protocol stack and a schematic diagram of a user plane protocol stack provided by an embodiment of the present application.
  • the single air interface can be understood as the terminal is directly connected to the access network device without connecting to the access network device through a relay node.
  • the UE in FIG. 4A and FIG. 4B may be the terminal 130 in FIG. 1
  • the gNB in FIG. 4A and FIG. 4B may be the access network device 150 in FIG. 1
  • the CU-DU separation architecture shown in FIG. 2 may be adopted .
  • the UE can access the CU through the DU, in which the functions of the RLC layer, MAC layer and PHY layer equivalent to the UE are implemented by the DU, and the functions of the RRC layer, SDAP layer and PDCP layer corresponding to the UE can be implemented by the CU. accomplish.
  • a peer-to-peer RRC layer and a PDCP layer are established between the UE and the CU.
  • the UE and the DU are connected through an interface (such as the Uu interface), and the peer RLC layer, MAC layer and PHY layer are established between the UE and the DU; the DU and the CU are connected through a control plane interface (such as the F1 control plane F1-control plane).
  • F1-C interface between DU and CU, there are peer-to-peer F1 application protocol (F1application protocol, F1AP) layer, stream control transmission protocol (stream control transmission protocol, SCTP) layer, Internet Protocol (Internet Protocol, IP) layer, layer(L)2 and layer(L)1.
  • a peer-to-peer SDAP layer and a PDCP layer are established between the UE and the CU.
  • the UE and the DU are connected through the Uu interface, and the equivalent RLC layer, MAC layer and PHY layer are established between the UE and the DU; the DU and the CU are connected through the F1 user plane (F1-user plane, F1-U) interface, and the DU
  • F1-user plane, F1-U F1 user plane
  • F1-U F1-U
  • a peer-to-peer general packet radio service (GPRS) tunneling protocol user plane (GPRS tunneling protocol-user plane, GTP-U) layer and user datagram protocol (UDP) layer are established between the CU and the CU. layer, IP layer, L2 and L1.
  • GPRS general packet radio service
  • 5A and 5B are respectively a schematic diagram of a control plane protocol stack and a schematic diagram of a user plane protocol stack in an IAB network provided by an embodiment of the present application.
  • the PHY layer, MAC layer and RLC layer that are equivalent to the terminal are located on the access IAB node, while the PDCP layer, SDAP layer and RRC layer that are equivalent to the UE are located on the IAB donor CU.
  • the RRC layer equivalent to the UE is located on the CP (that is, the donor-CU-CP) of the IAB donor CU, and the PDCP layer and SDAP layer that are equivalent to the UE are located on the UP of the IAB donor CU (that is, the donor-CU- UP).
  • a Uu interface is established between the terminal 1 and the DU of the IAB node 1, and the peer-to-peer protocol layers include the RLC layer, the MAC layer, and the PHY layer.
  • the DU of the IAB node 1 and the IAB donor CU1 establish an F1-C interface, and the equivalent protocol layers include the F1AP layer, the SCTP layer and the IP layer.
  • the F1 interface in the IAB host is established between the IAB donor DU 1 and the IAB donor CU 1, and the equivalent protocol layers include the IP layer, L2 and L1.
  • BL is established between IAB node 1 and IAB node 2, as well as between IAB node 2 and IAB donor DU 1, and the peer-to-peer protocol layers include Bakhaul Adaptation Protocol (BAP) layer, RLC layer, MAC layer and PHY layer.
  • BAP Bakhaul Adaptation Protocol
  • RLC Radio Link Control
  • MAC Media Access Control
  • PHY PHY Layer
  • a peer-to-peer RRC layer and a PDCP layer are established between the terminal 1 and the IAB donor CU 1
  • a peer-to-peer IP layer is established between the DU of the IAB node 1 and the IAB donor DU 1.
  • the BAP layer includes one or more of the following capabilities: adding routing information (routing information) that can be identified by a wireless backhaul node (IAB node) to a data packet;
  • the identified routing information performs routing, adds identification information to the data packet related to quality of service (QoS) requirements that can be identified by the wireless backhaul node, and performs routing for the data packet in multiple segments containing the wireless backhaul node.
  • QoS mapping on the link adding data packet type indication information to data packets, and sending flow control feedback information to nodes with flow control capabilities.
  • the name of the protocol layer with these capabilities is not necessarily the BAP layer, and may also be other names. Those skilled in the art can understand that as long as the protocol layer having these capabilities can be understood as the BAP layer in this embodiment of the present application.
  • control plane protocol stack of the IAB network is compared with the control plane protocol stack of the single air interface.
  • the DU connected to the IAB node realizes the function of the DU of the single air interface gNB, that is, the peer RLC layer and MAC layer are established with the terminal. and the functions of the PHY layer, as well as the functions of the F1AP layer, SCTP layer, and IP layer that establish equivalence with the CU.
  • the IAB donor CU implements the function of the CU of the single air interface gNB.
  • a Uu interface is established between the terminal 1 and the DU of the IAB node 1, and the peer-to-peer protocol layers include the RLC layer, the MAC layer, and the PHY layer.
  • the DU of the IAB node 1 and the IAB donor CU1 establish the F1-U interface, and the equivalent protocol layers include the GTP-U layer, the UDP layer and the IP layer.
  • the F1 interface in the IAB host is established between the IAB donor DU 1 and the IAB donor CU 1, and the equivalent protocol layers include the IP layer, L2 and L1.
  • BL is established between IAB node 1 and IAB node 2, and between IAB node 2 and IAB donor DU 1, and the peer-to-peer protocol layers include BAP layer, RLC layer, MAC layer and PHY layer.
  • a peer-to-peer SDAP layer and a PDCP layer are established between the terminal 1 and the IAB donor CU 1, and a peer-to-peer IP layer is established between the DU of the IAB node 1 and the IAB donor DU 1.
  • the user plane protocol stack of the IAB network is compared with the user plane protocol stack of the single air interface.
  • the DU of the IAB access node realizes part of the functions of the DU of the single air interface gNB, that is, it establishes a peer RLC layer, MAC layer with the terminal. Layer and PHY layer functions, as well as the functions of GTP-U layer, UDP layer and IP layer to establish equivalence with IAB donor CU 1.
  • the IAB donor CU implements the function of the CU of the single air interface gNB.
  • FIG. 5A and FIG. 5B only take the protocol stack in the IAB scenario shown in FIG. 3 as an example for description.
  • an IAB node may have one or more roles, and the IAB node may have protocol stacks of the one or more roles; or, the IAB node may have a set of protocol stacks, and the protocol stack may Different roles are processed using the protocol layers corresponding to different roles.
  • the following is an example of the protocol stack in which the IAB node has the one or more roles:
  • the IAB node When the IAB node starts to access the IAB network or after accessing the IAB network, it can play the role of the terminal, and the MT of the IAB node has the protocol stack of the terminal, for example, the protocol stack of the terminal 1 in FIG. 5A and FIG. 5B .
  • the IAB node can transmit its own upstream and/or downstream data packets (eg OAM data packets) with the IAB donor, perform measurements through the RRC layer, and so on.
  • OAM data packets eg OAM data packets
  • the IAB node After the IAB node accesses the IAB network, the IAB node can provide access services for the terminal, so as to play the role of an access IAB node. At this time, the IAB node has a protocol stack for accessing the IAB node, such as FIG. 5A and FIG. The protocol stack of IAB node 1 in 5B.
  • the IAB node After the IAB node accesses the IAB network, the IAB node can play the role of an intermediate IAB node. At this time, the IAB node has the protocol stack of the intermediate IAB node, such as the protocol stack of the IAB node 2 in FIG. 5A and FIG. 5B .
  • the IAB node may have protocol stacks for one or more roles of the above-mentioned terminal, access IAB node and intermediate IAB node.
  • FIG. 6 is a schematic diagram of group switching provided by an embodiment of the present application. The following description will be made with reference to FIG. 6 .
  • the IAB node 1 may provide access and/or backhaul services for one or more terminals and/or other IAB nodes.
  • the one or more terminals and/or other IAB nodes may be referred to as descendant nodes or subordinate nodes.
  • Figure 6 shows that IAB node 1 is connected to terminal 1 and IAB node 4, and IAB node 3 is connected to terminal 2, wherein IAB node 1 provides access services for terminal 1 and IAB node 4, and IAB node 4 is the terminal 2 provides access services, and IAB node 1 provides backhaul services for terminal 2.
  • IAB node 1 may also have one or more grandchild nodes, and IAB node 4 can provide access and/or backhaul services for more terminals or IAB nodes.
  • IAB node 4 can provide access and/or backhaul services for more terminals or IAB nodes. This application implements The example does not limit this.
  • IAB node 1 can switch. IAB node 1 switches from IAB node 2 to IAB node 3 (or IAB node 1 switches from a cell served by IAB node 2 to a cell served by IAB node 3), IAB node 2 is connected to IAB donor 1, and IAB node 3 is connected to IAB Donor 2 is connected.
  • the switch of the IAB node 1 can be called the switch of the cross-host node.
  • IAB node 1 can switch from IAB node 2 to IAB node 3 in the role of a terminal.
  • these descendant nodes can change from connecting to IAB node 2 to connecting to IAB node 3 along with IAB node 1. Since the host node of descendant nodes has also changed, it can be considered that descendants Nodes are also switched.
  • IAB node 1 and descendant nodes can be called a group, and the switching between IAB node 1 and descendant nodes can be called group switching or group switching.
  • a group that performs group switching may include one or more IAB nodes.
  • a node whose parent node changes during group switching is referred to as a migrating IAB node or a migrating node.
  • the migrating IAB node is The parent node before the group switch is the source parent node, and the parent node of the migrated IAB node after the group switch is the target parent node.
  • IAB node 1 can be called the migrated IAB node
  • IAB node 2 can be called as The source parent node of IAB node 1
  • IAB node 3 can be called the target parent node of IAB node 1.
  • IAB donor 1 may be called the source IAB donor of the group switch, or the source IAB donor of one or more nodes in the group, or the source IAB donor of one or more nodes in the group during the group switch process.
  • IAB donor 2 can be referred to as the target IAB donor for group handover, or the target IAB donor for one or more nodes in the group, or the target IAB for one or more nodes in the group during group handover donor.
  • the group handover process can be understood as the process of group handover, which can include the process of switching from the source IAB donor decision to one or more nodes in the group to perform the handover.
  • One or more nodes in the group may be handed over successfully or The handover fails, which is not limited in this embodiment of the present application.
  • the source IAB donor may be referred to as a source host node or a source access network device
  • the target IAB donor may be referred to as a target host node or a target access network device, which is not limited in this embodiment of the present application.
  • each node in the group needs to perform the handover process and re-initiate random access in the new cell after the handover. Re-initiating random access by each node in the system will impact the limited random access resources, and a large amount of signaling in the random access process will cause signaling storms.
  • the parent node of each descendant node may not change, and each descendant node
  • the cell served by the accessed parent node may not change (the identity of the cell itself may or may not change, for example, the NCGI or ECGI of the cell may change, and the physical cell identity PCI of the cell may not change), so It can be considered that the descendant nodes of the migrated IAB nodes in the group do not need to perform random access during the handover process (that is, perform random access-free handover), but random access-free handover may cause the node to be uncertain when the handover is successful.
  • the timer for detecting whether the handover is successful cannot be stopped in time, and the timeout of the timer will cause the handover to fail, and the node may initiate processes such as RRC reconstruction, which brings unnecessary delay.
  • the present application provides a solution, so that the nodes in the group that perform random access-free handover can receive indication information and can stop the timer in time according to the indication information, so as to improve the success rate of handover and reduce the probability of handover. Delay to ensure the communication performance after handover.
  • FIG. 7 is a communication method provided by the implementation of this application, which can be applied to a relay system such as an IAB system.
  • group switching may occur, that is, a certain group is switched from the source access network device to the target access network device.
  • the group that performs group switching includes at least a child node and a parent node. It can be understood that during the group switching process, the parent node of the child node does not change.
  • the group may also include one or more other IAB nodes, for example, the migrated IAB node in the group may be a parent node, and the group may also include other descendant nodes of the parent node except child nodes, Alternatively, the migrated IAB node in the group may be a node between the parent node and the source access network device, and the group may also include other descendant nodes of the node other than the parent node and child nodes.
  • the child node can be an IAB node or a terminal
  • the parent node can be an IAB node
  • the parent node's superior node can be an IAB node
  • the source access network device can be the source IAB donor
  • the target access network device can be for the target IAB donor.
  • the group that performs group switching includes IAB node 1, terminal 1, IAB node 4 and terminal 2.
  • the child node is terminal 1 or IAB node 4, and the parent node is IAB node 1; or, the child node is terminal 2, the parent node is IAB node 4, the source access network device is IAB donor 1, and the target access network device is IAB donor 2.
  • the method includes:
  • S701 The access network device sends a first message to the parent node.
  • the access network device may be the target access network device of the parent node and the child nodes of the parent node in the group switching process.
  • the parent node may be called a first node
  • the child node may be called a second node
  • one or more other nodes may exist between the second node and the access network device.
  • the description is given below with child nodes and parent nodes.
  • S701 may include the target access network device sending a first message to a source access network device, and the source access network device sending the first message to the parent node.
  • the source access network device may be the source access network device of the parent node and the child nodes of the parent node in the group switching process.
  • the source access network device can send the first node to the parent node through the other one or more nodes. information.
  • the first message sent by the target access network device to the source access network device may be included in a handover request response message, and the first message sent by the source access network device to the parent node.
  • a message may be included in the F1AP message (eg, UE context modification request message).
  • S702 The parent node sends a first message to the child node.
  • S701 to S702 can be expressed as: the access network device sends the first message to the child node through the parent node, or the child node receives the message from the access network through the parent node. the first message of the network device.
  • the child node may perform random access-free handover.
  • handover may also be referred to as RRC reconfiguration, master cell group (master cell group, MCG) change (change) or secondary cell group (secondary cell group, SCG) change.
  • the child node receives the first message may be referred to as before handover.
  • the first message may be a first RRC reconfiguration message.
  • the RRC reconfiguration message in this application may be referred to as a handover command message.
  • the first message may not include random access configuration information.
  • the first message may indicate that the child node is exempt from random access, and the indication may be explicit or implicit.
  • the indication may be explicit
  • the first message may include an indication that random access is exempted
  • the child node is exempted from random access according to the indication.
  • the indication may be an indication
  • the first message may not include the indication of free random access
  • the sub-node and the target access network device may agree that when the sub-node receives the first
  • the child node is exempt from random access
  • the child node and the target access network device may agree that when the first message does not include random access configuration information ; or, there are other ways to indicate in the implementation, which is not limited in this embodiment of the present application.
  • the first message may include a synchronous reconfiguration (reconfigurationwithsync) information element.
  • the above random access-free indication may be carried in the synchronous reconfiguration information element.
  • the synchronous reconfiguration information element does not include the configuration information of the random access.
  • the child node may determine that the child node needs to perform handover according to the synchronization reconfiguration information element, and avoid random access during the handover.
  • the parent node may have one or more child nodes, and the child node does not need to be randomly selected in the parent node's cell. Access can greatly reduce the number of random access initiated by child nodes. On the one hand, it can reduce the delay caused by handover, and on the other hand, it can avoid the situation that random access resources are limited when a large number of child nodes initiate random access.
  • the cell radio network temporary identifier (C-RNTI) of the child node before the handover and after the handover may remain unchanged.
  • the C-RNTI is used to uniquely identify the child node in the cell of the parent node, or it can be understood as the identification of the child node in the cell of the accessed parent node, and the name of the C-RNTI is not used in this embodiment of the present application.
  • the C-RNTI in this application can be replaced with other identifiers used to identify the sub-node in the cell.
  • the first message may not include the C-RNTI of the child node.
  • the first message does not include the C-RNTI of the child node, and after receiving the first message, the child node may continue to use the C-RNTI before receiving the first message by default.
  • the first message may include indication information indicating that the C-RNTI of the child node is unchanged.
  • the child node may determine that the C-RNTI of the child node remains unchanged according to the indication information, so that after receiving the first message, the child node continues to use the C-RNTI before receiving the first message.
  • the first message may include the C-RNTI of the sub-node before receiving the first message.
  • the child node can use the C-RNTI carried in the first message according to the C-RNTI.
  • the access network device serving the child node has changed.
  • the access network device serving the child node has changed from the source access network device to the target.
  • Access network equipment, and part of the identity of the cell to which the child node accesses is the identity of the access network equipment.
  • the identity has changed, that is, the partial configuration of the cell accessed by the child node has changed.
  • the C-RNTI of the child node can be kept unchanged, thereby reducing the process of configuring the C-RNTI of the child node, avoiding a large number of reconfiguring C-RNTI work in the group handover of the IAB, and reducing the number of child nodes.
  • the power consumption of the node saving the power of the child nodes.
  • the C-RNTI of the child node before handover and after handover can be changed.
  • the first message may include the updated C-RNTI, and the child node may use the updated C-RNTI in the first message during the handover process and after the handover is completed. This application does not limit this.
  • the child node After receiving the first message, the child node can start the timer.
  • the timer can be used to monitor whether the handover of the child node is successful.
  • the duration of the timer may be included in the above-mentioned first message.
  • the child node may perform random access-free handover, and after the handover is completed, the child node sends the second message to the parent node.
  • S705 The parent node sends a second message to the target access network device.
  • S705 and S706 may be expressed as: the child node sends the second message to the target access network device through the parent node; or, the target access network device receives the second message from the child node through the parent node.
  • the second message may be a first RRC reconfiguration complete message
  • the first RRC reconfiguration complete message may be referred to as a handover complete message.
  • S706 The target access network device sends the first indication information to the parent node.
  • the target access network device parses the second message, it can determine that the reconfiguration of the child node is completed, and the target access network device can send the first indication information to the parent node to trigger the parent node to send the second message to the child node. Instructions.
  • the first indication information may instruct the parent node to send the second indication information to the child node, or may indicate that the reconfiguration of the child node is completed, or may indicate that the child node may stop the timer, or the first indication information may indicate other content , as long as the indication information that can trigger the parent node to send the second indication information to the child node may be the first indication information in this application.
  • the first indication information may include the identifier of the child node. It can be understood that the parent node may have multiple child nodes, and the first indication information carries the identifiers of the child nodes, and the parent node can determine to which child node to send the second indication information after receiving the first indication information.
  • S706 is optional.
  • S707 The parent node sends the second indication information to the child node.
  • the parent node in response to the first indication information, sends the second indication information to the child node.
  • the parent node After the parent node receives the second message from the child node, or after the parent node sends the second message to the target access network device, it can be determined that the child node reconfiguration is completed, and the parent node can Send second indication information to the child node.
  • the second indication information may indicate to stop the timer.
  • the timer may be a T304 timer (timer) or the timer may have other names, which are not limited in this application.
  • the second indication information may be indicated in an explicit manner, the second indication information occupies 1 bit (bit) or multiple bits, and the 1 bit or multiple bits of information indicates to stop the timer.
  • the second indication information may be indicated in an implied manner.
  • the second indication information can be a first type of MAC CE, the first type can be understood as a certain type of MAC CE, and the sub-node can stop the timer when receiving the type of MAC CE.
  • the first type of MAC CE may not carry information or carry information, which is not limited in this embodiment of the present application.
  • the type of the MAC CE may be identified by a logical channel ID (Logical channel ID, LCID) corresponding to the MAC CE agreed in the protocol. This application does not limit the type of the MAC CE.
  • the second indication information may be indicated in an implied manner.
  • the second indication information may be a MAC CE carrying a UE Contention Resolution Identity (UE Contention Resolution Identity).
  • the MAC CE may be a specific type of MAC CE.
  • the type of the MAC CE may be identified by a logical channel identifier (logical channel identifier, LCID) corresponding to the MAC CE agreed in the protocol.
  • the MAC CE carrying the UE contention resolution identifier can be transmitted in the PDSCH, and the PDSCH is scheduled by the PDCCH, and the PDCCH is scrambled by the C-RNTI of the sub-node. Therefore, after the sub-node successfully parses the MAC CE carrying the UE contention resolution identifier, it can be considered that the second indication information has been received, thereby stopping the timer.
  • the MAC CE carrying the UE contention resolution identifier may be any type of MAC CE, which is not limited in this embodiment of the present application.
  • the UE contention resolution identifier may be any value, for example, the value may be the C-RNTI of the child node, or may be the value of one or more bits in the C-RNTI, or the value may be For any numerical value, the numerical value may have no meaning, which is not limited in this application.
  • the child node After receiving the second indication information, the child node stops the timer according to the second indication information.
  • the child node by sending the second indication information to the child node by the parent node, the child node can stop the timer in time to avoid handover failure and subsequent failure processing (for example, performing recovery operations such as RRC reconstruction) caused by timer timeout, Reduce the delay and improve the continuity of service transmission.
  • subsequent failure processing for example, performing recovery operations such as RRC reconstruction
  • the method in FIG. 7 may further include: the target access network device sends a third message to the parent node.
  • the target access network device may send the third message to the source access network device, and the source access network device may send the third message to the parent node.
  • the third message may be a third RRC reconfiguration message.
  • the parent node may perform random access-free handover according to the third message.
  • the third message may indicate that the parent node is exempt from random access, which may be explicit or implicit, and may refer to the content of the first message, which will not be described here.
  • the C-RNTI of the parent node before the handover and after the handover may be unchanged or changed. For details, refer to the content in S702, which will not be described here.
  • the parent node may perform random access switching according to the third message.
  • the third RRC reconfiguration message may include random access configuration information.
  • the parent node may start the timer after receiving the third message. This timer is used to monitor whether the handover of the parent node is successful.
  • the parent node may first receive the first message or send the first message to the child node first, and then receive the third message. In this way, it can be avoided that the parent node performs handover after receiving the third message, stops receiving messages and/or data from the source host node, and cannot forward the first message for the child node, which can be implemented in the following implementation manner.
  • the parent node after the parent node receives the first message or sends the first message to the child node, the parent node sends third indication information to the source access network device to trigger the source access network device to send the parent node Send a third message.
  • the third indication information may instruct the source access network device to send the third message to the parent node, or may indicate that the parent node has received the first message from the source access network device, or has sent the first message to the child node. message, or may indicate that the parent node is ready to receive a third message, and so on.
  • the information used to trigger the source access network device to send the third message to the parent node may be considered as the third indication information of the present application, and the third indication information may also indicate other content, which the embodiments of the present application do. Not limited.
  • the present application describes one child node. It can be understood that a parent node may have one or more child nodes, and each child node will receive the first message of the child node through the parent node.
  • the parent node may receive the first message of all child nodes from the source access network device, or after sending the first message of the child node to each child node, the parent node sends the first message to the source access network device.
  • Three instructions are possible.
  • the third indication information may be carried in an F1AP message, and the F1AP message may be a non-UE associated (non-UE associated) F1AP message.
  • the parent node may send an F1AP message to the source access network device, for example, for the In the UE context modification response message of the child node, the third indication information may be carried in the UE context modification response message sent by the parent node for the last child node.
  • the parent node may send an F1AP message to the source access network device, for example, a UE context modification response message for the child node
  • the source access network device may send the third message to the parent node after receiving the UE context modification response message.
  • the parent node can send F1AP to the source access network device.
  • message such as a UE context modification response message for the child node
  • the source access network device may send a third message to the parent node after receiving the UE context modification response message for all child nodes sent by the parent node.
  • the method in FIG. 7 may further include: the source access network device sends a handover request message to the target access network device, where the handover request message includes one or more of the following: cell radio network temporary identifiers of one or more nodes , the identity of the cell accessed by the one or more nodes and the level information of the one or more descendant nodes in the network topology.
  • the one or more nodes are one or more nodes in the group, including child nodes and parent nodes.
  • the hierarchical information of one or more nodes in the network topology is used to determine the duration of the timers of the one or more nodes.
  • the first message and/or the third message may be carried in a handover request response message sent by the target access network device to the source access network device.
  • the above-mentioned first message includes information on the duration of the timer, and in S703, the sub-node may set a timer according to the information on the duration of the timer, and start the timer.
  • the third message includes information on the duration of the timer.
  • the parent node After receiving the third message, the parent node starts a timer that is set according to the information on the duration of the timer in the first message, and starts the timer.
  • FIG. 8 is a method for group switching provided by an embodiment of the present application, which may be applied to a relay system such as an IAB system.
  • FIG. 7 will be further described below with reference to FIG. 8 .
  • a certain group performs group handover from a source access network device to a target access network device, and the group at least includes a first node, a second node and a third node.
  • the third node is the migration IAB node; the third node is the parent node of the second node, and the second node is the parent node of the first node.
  • the third node is connected to the source parent node before the handover, and the third node is connected to the target parent node after the handover.
  • the source parent node may be a source access network device, and the target parent node may be a target access network device.
  • the migrating IAB node is an IAB node that needs to replace the parent node in the switching process.
  • first node and the second node in FIG. 8 may be the child node and the parent node in FIG. 7, respectively, or the second node and the third node in FIG. 8 may be the child nodes and parent node.
  • the third node may also have one or more other child nodes, and the content of the second node in this application is also applicable to one or more other child nodes of the third node.
  • the second node may also have one or more other child nodes, and the content of the first node in this application is also applicable to one or more other child nodes of the second node.
  • the first node is terminal 2
  • the second node is IAB node 4
  • the third node is IAB node 1
  • the source access network device is IAB donor 1
  • the target access network device is IAB donor 2
  • the source access network device is IAB donor 2.
  • the parent node is IAB node 2
  • the target parent node is IAB node 3.
  • IAB node 1 also has a sub-node terminal 1, and the content of IAB node 4 is also applicable to terminal 1. If IAB node 4 also has a child node IAB node 5 (not shown in the figure), the content of terminal 2 is also applicable to IAB node 5.
  • the method includes:
  • S801 The third node sends a measurement report to the source parent node.
  • the source parent node sends a measurement report to the source access network device.
  • S803 The source access network device sends a handover request message to the target access network device.
  • the source access network device determines, according to the measurement report, that the third node switches from the source access network device to the target access network device, and sends a handover request message to the target access network device.
  • the group handover request message includes one or more of the following: the cell identifier of the cell accessed by each node (for example, an IAB node or a terminal) in the group, and the cell ID of the node in the accessed cell. C-RNTI, and the level information of this node in the network topology.
  • the cell identifier of the cell accessed by each node may be the cell identifier of the primary cell accessed by the node, and the primary cell may be called a special cell (special Cell, SpCell).
  • the cell identifier may include a physical cell identifier (PCI), an NR cell identifier (NR Cell Identity, NCI), and an NR cell global identifier (NCGI). ), one or more of the E-UTRAN cell global identifier (E-UTRAN cell global identifier, ECGI).
  • PCI physical cell identifier
  • NCI NR Cell Identity
  • NCGI NR cell global identifier
  • E-UTRAN cell global identifier E-UTRAN cell global identifier
  • the cell identifier of the cell to which the migrated IAB node (ie, the third node) is accessed may be the cell identifier of the target cell of the third node. It can be understood that after the source access network device decides to handover, it can decide to carry the cell identifier of the target cell of the third node in the handover request message and send it to the target access network device.
  • the cell identity of the target cell may be NGCI or ECGI.
  • the parent node of the descendant node of the migrated IAB node does not change during the group switching process.
  • the cell identifier of the cell accessed by the descendant node may be the cell identifier of the cell accessed by the descendant node before handover.
  • the cell identifier of the cell accessed by a node and the C-RNTI of the node in the accessed cell may uniquely identify the node.
  • the hierarchical information is used to indicate the relative position of a node in the network topology or the connection relationship with other nodes.
  • the level information may be the level or position relative to the migration relay node (that is, the third node).
  • the level of the third node is 0 (it may be other values, which are not limited in this embodiment of the present application)
  • the level of one or more child nodes of the third node is 1, that is, the level of the second node is 1, the level of one or more grandchild nodes of the third node is 2, that is, the level of the first node is 2, and so on , if a descendant node is connected to the third node through an X-hop link, the level information of the descendant node can be recorded as X, where X is a positive integer.
  • the level information may be a level relative to other nodes, and the other nodes may be the second node, the first node, or a node from the source parent node to the source host node, etc., which is not limited in this embodiment of the present application.
  • the handover request message may be a group handover request message
  • the group handover request message may be referred to as a group handover request message, which is used to request handover for a group.
  • Table 1 is a schematic diagram of a group switching request message. As shown in Table 1, the group switching request message includes multiple items, each item corresponds to a node, the item of each node further includes one or more items, and the one or more items include each node The cell identity, C-RNTI and/or level information of the accessed cell. In Table 1, the items of each node are juxtaposed.
  • Table 2 is another schematic diagram of a group switching request message.
  • the group handover request message includes one item, and the item corresponds to the third node.
  • the item of the third node further includes one or more items, and the one or more items include the cell accessed by the third node.
  • the item of the second node includes the cell identity of the cell accessed by the second node, the C-RNTI and/or level information, and the first node;
  • the item of the second node includes the cell identifier, C-RNTI and/or level information of the cell accessed by the second node.
  • the item of each node includes the items of the child nodes of that node.
  • the item of each node may not carry the hierarchical information of the node, through the mutual inclusion of the items of each node. relationship, you can get the hierarchical information of each node.
  • the relative topological relationship between the first node, the second node, and the third node can be inferred according to the structure of the information in Table 2 (the second node is a child node of the third node, and the first node is the second node child nodes), and then the level information of each node can be obtained (for example, if the level of the third node is 0, the level of the second node is 1, and the level of the first node is 2).
  • the handover request message may include one or more independent handover request messages, wherein one handover request message corresponds to a node, or can be understood as a handover request message for a node to request handover.
  • the handover request message of each node includes the cell identifier of the cell to which the node is accessed, the C-RNTI of the cell to which the node is accessed, and/or the node in the network topology. level information.
  • the target access network device sends a handover request response message to the source access network device.
  • the handover request response message in S804 may be a group handover request response message, and the group handover request response message may be referred to as a group handover request response message.
  • the group handover request response message includes an RRC reconfiguration message of each node.
  • this application refers to the RRC reconfiguration message of the first node as the first RRC reconfiguration message, the RRC reconfiguration message of the second node as the second RRC reconfiguration message, and the RRC reconfiguration message of the third node as the second RRC reconfiguration message. Called the third RRC reconfiguration message.
  • the group handover request response message includes a first RRC reconfiguration message, a second RRC reconfiguration message and a third RRC reconfiguration message.
  • the handover request message in S803 includes one or more independent handover request messages
  • the handover request response message in S804 may include one or more independent handover request response messages, wherein each handover request The response message corresponds to a node, and the handover request response message of each node includes the RRC reconfiguration message of the node.
  • the handover request message of S803 includes a first handover request message, a second handover request message and a third handover request message
  • the handover request response message of S804 includes a first handover request response message, the second handover request message A request response message and a third handover request response message.
  • the first handover request response message is the handover request response message of the first node, including the first RRC reconfiguration message
  • the second handover request response message is the handover request response message of the second node, including the second RRC reconfiguration message
  • the third handover request response message is the handover request response message of the third node, including the third RRC reconfiguration message.
  • the RRC reconfiguration message of each node may include duration information of the timer of the node.
  • the duration information of the timer of the node is further described below.
  • the target access network device may determine the duration of the timer of the node according to the level information of each node in the handover request response message in S803.
  • a descendant node with a larger level can be understood as a node with more hops in the backhaul link with the migration node (ie, the third node), and the timer duration is longer; a node with a smaller level , it can be understood that the node with fewer hops of the backhaul link with the third node has a shorter duration of the timer.
  • the level of the first node is 2, the duration of the timer of the first node is 200ms; the level of the second node is 1, the duration of the timer of the second node is 150ms; the level of the third node is 0, and the duration of the timer of the third node is 0.
  • the duration of the node's timer is 100ms.
  • the duration information of the timer may directly indicate the duration of the timer.
  • the duration information of the timer of the first node indicates 200ms
  • the duration information of the timer of the second node indicates 150ms
  • the duration information of the timer of the third node indicates 100ms.
  • the duration information of the timer may include one or more parameters, and the one or more parameters are used to determine the duration of the timer. After each node receives the duration information of the timer of the node, it can obtain the duration of the timer according to the one or more parameters.
  • the one or more parameters may obtain the duration of the timer through a certain operation, and the operation may include multiplication or exponentiation, and the application does not limit the operation method.
  • the one or more parameters include the duration of the basic timer and the scaling factor, and each node can obtain the duration of the timer of the node by performing an operation on the duration of the basic timer and the scaling factor.
  • the duration information of the timer of the first node includes the duration of the basic timer of 50ms and the scaling factor of 4.
  • the first node can multiply 50 by 4 to obtain the duration of the timer of the first node of 200ms; the timer of the second node
  • the duration information includes the duration of the basic timer of 50ms and the scaling factor of 3.
  • the first node can multiply 50 by 3 to obtain the duration of the timer of the first node of 150ms.
  • the duration information of the timer of the first node includes the duration of the basic timer of 50ms and the scaling factor of 2.
  • the first node can multiply 50 by 2 to obtain the duration of the timer of the first node of 100ms.
  • the target access network device can reasonably determine the duration of the timer according to the level of the node, so as to avoid handover failure caused by the unreasonable setting of the timer duration. , which can reduce the handover delay and reduce signaling overhead.
  • the handover request message and the handover request response message in S803 to S804 may refer to each other with the handover request message and the handover request response message in FIG. 7 .
  • the source access network device sends a downlink F1AP message, such as a UE context modification request (UE context modification request) message, to the second node, including the first RRC reconfiguration message.
  • a downlink F1AP message such as a UE context modification request (UE context modification request) message
  • the downlink F1AP message may further include indication information for instructing the second node to stop data transmission with the first node.
  • the indication information may be carried in a transmission action indicator (transmission action indicator) information element.
  • the second node may read the indication information, and then stop data transmission with the first node, including downlink data transmission and/or uplink data transmission with the first node. Specifically, the second node may stop data transmission with the first node after performing step S806.
  • S806 The second node sends the first RRC reconfiguration message to the first node.
  • the first RRC reconfiguration message may not include random access configuration information.
  • the first RRC reconfiguration message may indicate that the child node is exempt from random access, which may be explicit or implicit, and reference may be made to the content of the first message in S702.
  • the C-RNTI of the first node before and after the handover may remain unchanged.
  • the first RRC reconfiguration message may not include the C-RNTI of the first node, or indicate the C-RNTI of the first node.
  • the C-RNTI of the first node before handover and after handover may vary. For details, refer to the content in S702.
  • S807 The first node starts a timer.
  • the first node may start a timer after receiving the first RRC reconfiguration message.
  • the first node may start a timer after receiving the first RRC reconfiguration message.
  • the first node may obtain the duration of the timer according to the information on the duration of the timer, set the timer, and then start the timer.
  • the second node sends an uplink F1AP message to the source host node, such as a UE context modification response (UE CONTEXT MODIFICATION RESPONSE) message.
  • UE CONTEXT MODIFICATION RESPONSE UE context modification response
  • Step S808 is an optional step. If the downlink F1AP message in step S805 is a UE context modification request message, step S808 is required.
  • the UE context modification response message in S808 may be understood as the UE context modification response message fed back by the second node to the first node.
  • the first node sends a first RRC reconfiguration complete message to the second node.
  • the source access network device sends a downlink F1AP message to the third node, such as a UE context modification request (UE context modification request) message, which includes a second RRC reconfiguration message.
  • the downlink F1AP message (for example, a UE context modification request message) may further include indication information for instructing the third node to stop data transmission with the second node.
  • the third node may read the indication information, and then stop data transmission with the second node, including downlink data transmission and/or uplink data transmission with the second node.
  • the content of the indication information may refer to the content of S805.
  • S810 may occur after S805 and/or S806. Specifically, it can be done in the following ways:
  • the second node may send indication information to the source access network device to trigger the source access network device to send the second RRC reconfiguration message to the second node, that is, to trigger the source access network device to send a second RRC reconfiguration message.
  • the network device executes S810.
  • For the indication information reference may be made to the content of the third indication information in FIG. 7 .
  • the second node may receive RRC reconfiguration messages of all child nodes from the source access network device or send RRC reconfiguration messages to all child nodes. After that, the indication information is sent to the source access network device.
  • the second node is IAB node 4
  • the first node can be terminal 2
  • IAB node 4 can have child node IAB node 5 in addition to child node terminal 2 (not shown in Fig. 6)
  • IAB node 4 sends indication information to IAB donor 1.
  • IAB node 4 sends the first RRC reconfiguration message to terminal 2
  • IAB node 4 sends the RRC reconfiguration message of IAB node 5 to IAB node 5, IAB node 4 sends indication information to IAB donor 1.
  • the indication information may be carried in the uplink F1AP message sent to the source access network device.
  • the indication information may be carried in an uplink F1AP message (for example, a UE context modification request response message) sent by the second node for the last child node.
  • an uplink F1AP message for example, a UE context modification request response message
  • the IAB node 4 first receives the UE context modification request message of the terminal 2 from the IAB donor 1, which includes the RRC reconfiguration message of the terminal 2, and the IAB node 4 sends the RRC reconfiguration message to the terminal 2.
  • the IAB donor 1 sends the UE context modification request response message
  • the IAB node 4 receives the UE context modification request message of the IAB node 5 from the IAB donor 1, which includes the RRC reconfiguration message of the IAB node 5, and the IAB node 4 sends the IAB node 5.
  • Send RRC reconfiguration information IAB node 4 sends UE context modification request response message to IAB donor 1 for IAB node 5.
  • the indication information can be carried in the UE context modification request response message sent by the IAB node 4 to the IAB donor 1 for the IAB node 5.
  • the source access network device may perform S810 after S808.
  • the source access network device may perform S810 after receiving the UE context modification response message for all child nodes from the second node.
  • IAB donor 1 performs S810 after receiving the UE context modification request response message for terminal 2 and the UE context modification request response message for IAB node 5 sent by IAB node 4 from IAB node 4.
  • S811 The third node sends a second RRC reconfiguration message to the second node.
  • the second RRC reconfiguration message may not include random access configuration information.
  • the second RRC reconfiguration message may indicate that the child node is exempt from random access, which may be explicit or implicit, and reference may be made to the content of the first message in FIG. 7 .
  • the C-RNTI of the second node before and after the handover may remain unchanged.
  • the second RRC reconfiguration message may not include the C-RNTI of the second node, or indicate the C-RNTI of the second node.
  • the C-RNTI of the second node before handover and after handover may vary. For details, refer to the content in S702.
  • the second node may start a timer after receiving the second RRC reconfiguration message.
  • the second node may start a timer after receiving the second RRC reconfiguration message.
  • the second node may obtain the duration of the timer according to the information on the duration of the timer, set the timer, and then start the timer.
  • the third node sends an uplink F1AP message, such as a UE context modification response message, to the source donor node.
  • an uplink F1AP message such as a UE context modification response message
  • Step S813 is an optional step. If the downlink F1AP message in step S810 is a UE context modification request message, step S813 is required.
  • the UE context modification response message in S813 may be understood as the UE context modification response message fed back by the third node to the second node.
  • S814 The second node sends a second RRC reconfiguration complete message to the third node.
  • the source access network device sends a downlink F1AP message, such as a UE context modification request (UE context modification request) message, to the source parent node, including a third RRC reconfiguration message.
  • a downlink F1AP message such as a UE context modification request (UE context modification request) message
  • the downlink F1AP message may further include instruction information instructing the source parent node to stop data transmission with the third node.
  • the source parent node may read the indication information, and then stop data transmission with the third node, including downlink data transmission and/or uplink data transmission with the third node.
  • the indication information refer to the content in S805 and S810.
  • S815 may occur after S810 and/or S811. Specifically, it can be achieved in the following ways:
  • the third node may send indication information to the source access network device to trigger the source access network device to send the third RRC reconfiguration message to the third node.
  • indication information reference may be made to the content of the third indication information in FIG. 7 .
  • the third node may receive RRC reconfiguration messages of all subnodes from the source access network device or send RRC reconfiguration messages to all subnodes Afterwards, the indication information is sent to the source access network device.
  • the third node is IAB node 1, and the second node is IAB node 4.
  • IAB node 1 can also have child node terminal 1, then IAB node 1 from IAB donor 1
  • the IAB node 1 can send the indication information to the IAB donor 1.
  • the IAB node 1 sends the second RRC reconfiguration message to the IAB node 4, and sends the RRC reconfiguration message of the terminal 1 to the IAB node 1 to the terminal 1, the IAB node 1 sends the indication information to the IAB donor 1.
  • the source access network device may perform S815 after S813.
  • the source access network device may perform S815 after receiving the UE context modification response message for all child nodes from the third node.
  • IAB donor 1 performs S815 after receiving the UE context modification request response message for terminal 1 and the UE context modification request response message for IAB node 4 sent by IAB node 1 from IAB node 1.
  • S816 The source parent node sends a third RRC reconfiguration message to the third node.
  • the third RRC reconfiguration message may instruct the third node to perform random access in the target cell
  • the third RRC reconfiguration message may include the cell identity of the target cell (eg, the PCI of the target cell).
  • the target cell is the cell served by the target parent node of the third node.
  • the third RRC reconfiguration message may include random access configuration information and/or a new C-RNTI.
  • the third RRC reconfiguration message may indicate that the third node is exempt from random access.
  • the third RRC reconfiguration message may not include random access configuration information.
  • the third RRC reconfiguration message may indicate that the child node is exempt from random access, which may be explicit or implicit, and reference may be made to the content of the first message in FIG. 7 .
  • the third node does not need to synchronize with the target parent node.
  • the third node is free from random access, which can avoid the delay caused by random access and reduce the delay of handover. On the other hand, it can avoid the situation of limited random access resources.
  • the C-RNTI of the third node before and after the handover may remain unchanged.
  • the third RRC reconfiguration message may not include the C-RNTI of the third node, or indicate the C-RNTI of the third node.
  • the C-RNTI of the third node before handover and after handover may vary. For details, refer to the content in S702.
  • S817 The third node starts a timer.
  • the third node may start the timer after receiving the third RRC reconfiguration message.
  • the third node may start the timer after receiving the third RRC reconfiguration message.
  • the third node may obtain the duration of the timer according to the information on the duration of the timer, set the timer, and then start the timer.
  • the source parent node sends an uplink F1AP message, such as a UE context modification response message, to the source host node.
  • an uplink F1AP message such as a UE context modification response message
  • Step S818 is an optional step. If the downlink F1AP message in step S815 is a UE context modification request message, step S818 is required.
  • the UE context modification response message in S818 may be understood as the UE context modification response message fed back by the source parent node to the third node.
  • the third node may perform random access or free random access in the target cell according to the third RRC reconfiguration message.
  • Mode 1 and Mode 2 are performed alternatively. Wherein, mode 1 includes S819 and S820, and mode 2 includes S823 to S825. Regardless of mode 1 or mode 2, S821 and S822 exist.
  • the third node may perform random access according to the third RRC reconfiguration message.
  • the third node can re-synchronize with the target parent node through the random access process to ensure the performance of the communication between the third node and the target parent node.
  • the third node may stop the timer.
  • the third node sends a third RRC reconfiguration complete message to the target parent node.
  • the target parent node sends a third RRC reconfiguration complete message to the target access network device.
  • the third RRC reconfiguration complete message in S822 may be carried in an uplink F1AP message, such as an uplink RRC message transfer (UL RRC message transfer) message.
  • an uplink RRC message transfer UL RRC message transfer
  • the target access network device sends the first indication information to the target parent node.
  • the third node is free of random access, and there are no S819 and S820.
  • the target access network device parses the third RRC reconfiguration complete message, it can be determined that the third node handover is completed, and the target access network is complete.
  • the network access device may send the first indication information to the target parent node to trigger S824.
  • S823 is optional.
  • S824 The target parent node sends the second indication information to the third node.
  • the target parent node in response to the first indication information, sends the second indication information to the third node.
  • the target parent node sends the second indication information to the third node.
  • the third node After receiving the second indication information, the third node stops the timer according to the second indication information.
  • the source access network device sends a message containing the transmission status of the data packet to the target access network device, such as a sequence number (sequence number, SN) status transfer (SN Status Transfer) message.
  • a sequence number sequence number, SN
  • SN Status Transfer SN Status Transfer
  • uplink data packet and/or downlink data packet may be a PDCP packet data unit (packet data unit, PDU).
  • PDU packet data unit
  • the target access network device After receiving the SN Status Transfer message, the target access network device can continue the uplink and/or downlink data transmission after the third node completes the handover according to the data packet transmission status in it, so as to avoid the loss of terminal service data.
  • the CP of the CU of the source access network device may initiate a bearer context modification process to obtain the uplink/downlink data packet transmission status (for example, corresponding to SN status information of the PDCP PDU carried by each UE data radio), and exchange endpoint configuration information for data forwarding between the source access network device and the target access network device.
  • a bearer context modification process to obtain the uplink/downlink data packet transmission status (for example, corresponding to SN status information of the PDCP PDU carried by each UE data radio), and exchange endpoint configuration information for data forwarding between the source access network device and the target access network device.
  • the CP of the CU of the source access network device may send a bearer context modification request message to the UP of the CU of the source access network device, and the UP of the CU of the source access network device may send the UP of the CU of the source access network device to the CP of the CU of the source access network device Send a bearer context modification response message, the bearer context modification response message includes the SN status information of the uplink/downlink PDCP PDU, and may also include the UP of the source access network device CU for data forwarding (data forwarding) tunnel endpoint information.
  • the source access network device sends the data and the SN status to the CP of the CU of the target access network device.
  • the CP of the CU of the target access network device may initiate a bearer context modification process, thereby sending the downlink transport network layer address information (DL TNL address information) of the F1-U interface to the UP of the CU of the target access network device, and/or, The transmission status of the data packet (eg, SN status information corresponding to the PDCP PDU of each UE data radio bearer).
  • DL TNL address information downlink transport network layer address information
  • the CP of the CU of the target access network device may send a bearer context modification request message to the UP of the CU of the target access network device, where the context modification request message includes the transmission status of the data packet, the CU of the target access network device
  • the UP may send a bearer context modification response message to the CP of the CU of the target access network device.
  • the method in FIG. 8 may further include: the target access network device sends an RRC reconfiguration message to the third node, where the RRC reconfiguration message may include the configuration information of the BAP layer of the third node, and/or the third node and the third node.
  • the configuration information of the BAP layer of the third node and/or the configuration information of the backhaul RLC channel between the third node and the target parent node may be included in the third RRC reconfiguration message in S815 and S816.
  • the configuration information of the BAP of the third node may include the identification of the BAP layer allocated by the target access network device for the third node, and the routing identification (BAP routing ID) of the default (default) upstream BAP layer.
  • the configuration information of the BAP of the third node may also include: one or more other non-default upstream BAP layer routing identifiers, and the next hop of the third node corresponding to each uplink BAP layer routing identifier (that is, The BAP layer identifier of the target parent node).
  • the routing identifier of each uplink BAP layer includes a BAP address (BAP address) and a BAP path identifier (BAP path ID), and the BAP address is used to identify the target connection.
  • BAP address BAP address
  • BAP path ID BAP path identifier
  • the configuration information of the BAP layer of the third node included in the RRC reconfiguration message can be used to transmit the corresponding data packets in step S827, including, for example, establishing an F1 interface between the third node and the target access network device.
  • the configuration information of the RLC channel sent back between the third node and the target parent node may include configuration information of the default RLC channel sent back between the third node and the target parent node, and the like.
  • S827 The third node establishes an F1 interface with the target access network device.
  • the third node before establishing the F1 interface, the third node establishes an SCTP association (Association) with the target access network device.
  • SCTP association Association
  • the third node may initiate the establishment process of the F1 interface to the target access network device.
  • the third node may initiate the reestablishment process of the F1 interface to the target access network device, thereby triggering the target access network device to request from the source access network device the source access network device maintained at the source access network device and the third node.
  • the context of the F1 interface between nodes, and then the target access network device updates the context of the F1 interface.
  • the target access network device first obtains the context of the F1 interface between the source access network device and the third node maintained by the source access network device from the source access network device, and then the target access network device can initiate F1
  • the interface context update process updates the context of the F1 interface between the source access network device and the third node.
  • the method may further include: the target access network device sends the updated configuration of the BAP layer to the third node, and the configuration information in this step may include one or more of the following contents:
  • the third node is used as the uplink mapping configuration when accessing the IAB node, the BAP layer routing identifier used for sending uplink data packets, the identifier of the next hop node corresponding to the routing identifier, and the relationship between the third node and the next hop node.
  • the identifier of the BH RLC channel used to carry such uplink data packets, and the uplink data packets here can be any of the following: UE-related F1AP messages, non-UE-related F1AP messages, non-F1 interface messages, And the F1-U data packet; the bearer mapping relationship when the third node is used as an intermediate IAB node, specifically including: the identity of the previous hop node of the third node, the BH RLC on the link between the third node and the previous hop node.
  • the third node sends an uplink F1AP message to the target access network device, which includes a second RRC reconfiguration complete message.
  • the second RRC reconfiguration complete message of S828 may be carried in the UL RRC message transfer message.
  • S829 The target access network device sends third indication information to the third node.
  • the target access network device After the target access network device receives the second RRC reconfiguration complete message and parses the second RRC reconfiguration complete message, it can determine that the handover of the second node is completed, and the target access network device can send the third node to the third node. indicating information to trigger S830.
  • S829 is optional.
  • S830 The third node sends fourth indication information to the second node.
  • the third node in response to the third indication information, the third node sends the fourth indication information to the second node.
  • the second node After receiving the fourth indication information, the second node stops the timer according to the fourth indication information.
  • S832 The second node establishes an F1 interface with the target access network device.
  • the target access network device may also send BAP layer configuration information and/or backhaul RLC channel configuration information to the second node.
  • BAP layer configuration information and/or backhaul RLC channel configuration information For details, refer to the content of the third node, and replace the third node in S827. for the second node.
  • the second node sends an uplink F1AP message to the target access network device, which includes the first RRC reconfiguration complete message.
  • the first RRC reconfiguration complete message in S830 may be carried in the UL RRC message transfer message.
  • S834 The target access network device sends fifth indication information to the second node.
  • the target access network device After the target access network device receives the first RRC reconfiguration complete message and parses the first RRC reconfiguration complete message, it can determine that the handover of the first node is completed, and the target access network device can send a fifth message to the second node. indicating information to trigger S835.
  • S835 The second node sends fifth indication information to the first node.
  • the second node in response to the fourth indication information, the second node sends fifth indication information to the first node.
  • the second node sends fourth indication information to the first node.
  • S836 The first node stops the timer.
  • the first node After receiving the fifth indication information, the first node stops the timer according to the fifth indication information.
  • S837 The target access network device and the core network complete the path switching.
  • the core network transfers the user plane path for transmitting the services of the third node and its descendant nodes from the source access network device to the target access network device.
  • the target access network device sends a UE context release (UE context release) message to the source access network device.
  • UE context release UE context release
  • the CP of the CU of the source access network device may receive a UE context release message from the target access network device, and the CU of the source access network device may receive a UE context release message.
  • the CP may send a bearer context release command (bearer context release command) to the UP of the CU of the source access network device.
  • S839 and S840 describe the UE context release procedure of the F1 interface between the source access network device and the source parent node.
  • the source access network device sends a UE context release command (UE context release command) message to the source parent node.
  • UE context release command UE context release command
  • the source parent node sends a UE context release Complete (UE context release Complete) message to the source access network device.
  • UE context release Complete UE context release Complete
  • S841 Release the BAP routing configuration on the path between the source access network device and the third node.
  • the nodes on the path between the source access network device and the third node include the source access network device, and other nodes between the source access network device and the third node, for example, the source parent node.
  • the source access network device in this step may specifically be the DU part in the source access network device.
  • S841 may specifically include: the source access network device sends an F1AP message for releasing the BAP layer configuration related to the third node or the first node or the second node to the nodes on the path respectively, and the nodes on the path After receiving the F1AP message, release the corresponding BAP layer configuration of the node.
  • the actions performed by the access network device may be performed by the CU of the access network device or the CP of the CU.
  • the first node in FIG. 8 may be the child node in FIG. 7
  • the second node may be the parent node in FIG. 7
  • the contents of S804 to S807 can refer to each other with the contents of S701 to S703, S809 can refer to S704, S833 can refer to S705, and S834 to S836 can refer to S706 to S708.
  • the content of the second RRC reconfiguration message in S810 to S811 may refer to each other with the content of the third message in FIG. 7 .
  • the second node in FIG. 8 may be the child node in FIG. 7
  • the third node in FIG. 8 may be the parent node in FIG. 7
  • the contents of S804, S810 to S812 can be cross-referenced with the contents of S701-S703, S814 can be cross-referenced with S704, S828 can be cross-referenced with S705, and S829-S831 can be cross-referenced with S706-S708.
  • the contents of the third RRC reconfiguration messages of S815 to S816 may refer to each other with the contents of the third message in FIG. 7 .
  • the methods of the first node, the second node, and the third node may all be implemented independently, for example, the method of the third node may be implemented independently.
  • the methods of the first node, the second node and the third node may be implemented in a combined manner.
  • the combination may include the first node and the second node, the second node and the third node, and the first node and the second node.
  • the method in FIG. 8 may only include S804, S805 and S806, that is, the first node receives the first RRC reconfiguration information from the target access network device through the second node, and the first RRC reconfiguration message indicates that Free random access.
  • the C-RNTI of the first node before handover and after handover may remain unchanged.
  • one or more other steps in FIG. 8 may also be included.
  • Using the first RRC reconfiguration message to indicate the free random access can reduce the handover time of the node, reduce the handover delay, save the signaling overhead, and avoid a large number of nodes initiating random access due to resource constraints. Frequent collisions or nodes waiting for random access It takes too long to enter resources. In addition, by keeping the C-RNTI unchanged, a lot of reconfiguration work can be avoided, and the power consumption of the first node can be saved.
  • the method in FIG. 8 may only include S805 , S806 , S810 and S811 , and S810 may occur after S805 and/or S806 , for details, please refer to the content in FIG. 8 .
  • the first RRC reconfiguration message and/or the second RRC reconfiguration message may indicate random access or random access, which is not limited in this embodiment of the present application.
  • one or more other steps in FIG. 8 may also be included.
  • the method in FIG. 8 may only include S803, that is, the source access network device sends a handover request message to the target access network device, including the C-RNTI of one or more nodes, the accessed cell cell identities and/or hierarchy information in the network topology.
  • the target access network device determines the duration information of the timer according to the level information, and carries it in the RRC reconfiguration message and sends it to the one or more nodes.
  • the target access network device determines the duration information of the timer according to the level information, and carries it in the RRC reconfiguration message and sends it to the one or more nodes.
  • the content of FIG. 8 please refer to the content of FIG. 8 .
  • one or more other steps in FIG. 8 may also be included.
  • the RRC reconfiguration message is first sent to the farthest node in the group (for example, the first node in Figure 8), and then sent step by step.
  • the first-level RRC reconfiguration complete message is sent, and finally the RRC reconfiguration complete message of the farthest node is sent. Therefore, it can be understood that, in the group handover, the node with a larger number of hops of the wireless backhaul link with the migrating IAB node takes a longer time from the start of the handover to the completion of the handover.
  • the node in the group handover may fail to switch due to the timeout of the timer.
  • the node will initiate RRC re-establishment after judging that the handover fails, and the initiation of the RRC re-establishment process will bring delay and cause Unnecessary signaling overhead.
  • the child node initiates RRC reconstruction, if the switching of the parent node has not been completed, the parent node cannot provide services for the child node, which may also cause the RRC reconstruction of the child node to fail.
  • the required time delay is very large, which seriously affects the user experience.
  • the source access network device sends the level information to the target access network device, and the target access network device can reasonably determine the duration of the timer according to the level of the node.
  • a node with a larger hop count has a longer timer duration, and a node with a smaller hop count on the wireless backhaul link with the migrating IAB node has a smaller timer duration. Avoiding the above consequences caused by the unreasonable setting of the timer duration can reduce the handover delay and reduce signaling overhead.
  • each node may receive its own reconfiguration message. Considering that some information in the reconfiguration message of each node may be the same, the present application provides a reconfiguration message. Solution, in this solution, the target access network device can send the same information by way of broadcasting.
  • the target access network device broadcasts a group reconfiguration message, where the group reconfiguration message includes the public configuration of the primary serving cell, the indication of free random access, and/or the duration information of the timer, and the like.
  • the group reconfiguration message may be called a group switching command.
  • the duration information of the timer may indicate the duration of the basic timer in S804, and then the target access network device may send a message to each node in the group, where the message includes the scaling factor, and the The node obtains the duration of the timer according to the duration of the base timer and the scaling factor.
  • the target access network device may also separately send a message to each node in the group, where the message includes different information between each node, for example, the configuration of the PDCP layer of each node (such as security-related information). configuration), etc.
  • the above-mentioned broadcasting method can avoid the overhead caused by individually sending signaling to multiple nodes in the group.
  • FIG. 7 and FIG. 8 take the relay system as an example for introduction. It should be noted that the method in this embodiment of the present application is also applicable to a single air interface scenario in which a terminal directly accesses an access network device, for example, the terminal 130 in FIG. 1 . A scenario in which the access network device 150 communicates directly.
  • Fig. 9 is another communication method provided by an embodiment of the present application, which can be applied to a scenario where a terminal directly accesses an access network device. The following description will be made with reference to FIG. 9 .
  • the access network device 150 may adopt the CU-DU separation architecture shown in FIG. 2 .
  • the terminal 130 may switch from the access network device 150 to another access network device (not shown in FIG. 1 ), and the access network device 150 is hereinafter referred to as the source access network device, and the other access network device is
  • the network device is called the target access network device, and the target access network device may adopt the CU-DU separation architecture shown in FIG. 2, wherein the CU of the target access network device may be called the target CU, and the target access network device A DU may be referred to as a target DU.
  • S901 The target CU sends a first message to the source access network device.
  • the source access network device may adopt a CU-DU separation architecture, wherein the CU of the source access network device may be referred to as the source CU, and the DU of the source access network device may be referred to as the source DU.
  • S901 may include: the target CU sends a first message to the source CU.
  • S902 The source access network device sends a first message to the terminal.
  • S902 may include: the source CU sends the first message to the source DU, and the source DU sends the first message to the terminal.
  • S903 The terminal starts a timer.
  • S904 The terminal sends the second message to the target DU.
  • the target DU sends a second message to the target CU.
  • the first message and the second message in S901 to S905 may refer to the content of the first message and the second message in FIG. 7 .
  • S906 The target CU sends the first indication information to the target DU.
  • the target DU sends second indication information to the terminal.
  • the first indication information and the second indication information in S906 to S907 may refer to the content of the first indication information and the second indication information in FIG. 7 .
  • the target DU in FIG. 9 can perform the actions of the parent node in FIG. 7
  • the target CU in FIG. 9 can perform the actions of the access network device in FIG. 7
  • the terminal in FIG. 9 can perform the actions of the child node in FIG. 7 .
  • FIG. 7 For other contents of FIG. 9 , reference may be made to FIG. 7 , which will not be repeated here.
  • FIGS. 10 to 13 The apparatuses provided in the embodiments of the present application are described below with reference to FIGS. 10 to 13 .
  • the apparatuses in FIGS. 10 to 13 can complete the methods in FIGS. 7 to 9 , and the content of the apparatus and the content of the method may be referred to each other.
  • FIG. 10 is a schematic structural diagram of a terminal provided by an embodiment of the present application, where the terminal can implement the functions of the terminal in the foregoing method embodiment.
  • Figure 10 illustrates the main components of the terminal, as shown in Figure 10:
  • the terminal includes at least one processor 611 , at least one transceiver 612 and at least one memory 613 .
  • the processor 611 , the memory 613 and the transceiver 612 are connected.
  • the terminal may further include an output device 614 , an input device 615 and one or more antennas 616 .
  • the antenna 616 is connected to the transceiver 612 , and the output device 614 and the input device 615 are connected to the processor 611 .
  • the processor 611 is mainly used to process communication protocols and communication data, control the entire terminal, execute software programs, and process data of the software programs.
  • the terminal device may include a baseband processor and a central processing unit.
  • the baseband processor is mainly used to process communication protocols and communication data.
  • the central processing unit is mainly used to control the entire terminal equipment, execute the software program, and process the data of the software program.
  • the processor in FIG. 10 may integrate the functions of the baseband processor and the central processing unit.
  • the baseband processor and the central processing unit may also be independent processors, interconnected by technologies such as a bus.
  • a terminal device may include multiple baseband processors to adapt to different network standards, a terminal device may include multiple central processors to enhance its processing capability, and various components of the terminal device may be connected through various buses.
  • the baseband processor may also be expressed as a baseband processing circuit or a baseband processing chip.
  • the central processing unit can also be expressed as a central processing circuit or a central processing chip.
  • the function of processing the communication protocol and communication data may be built in the processor, or may be stored in the memory in the form of a software program, and the processor executes the software program to realize the baseband processing function.
  • the memory 613 is mainly used to store software programs and data.
  • the memory 613 may exist independently and be connected to the processor 611 .
  • the memory 613 may be integrated with the processor 611, for example, integrated within a chip, that is, an on-chip memory, or the memory 613 is an independent storage element, which is not limited in this embodiment of the present application.
  • the memory 613 can store program codes for implementing the technical solutions of the embodiments of the present application, and is controlled and executed by the processor 611 .
  • the transceiver 612 can be used for converting the baseband signal to the radio frequency signal and processing the radio frequency signal, and the transceiver 612 can be connected to the antenna 616 .
  • the transceiver 612 includes a transmitter (Tx) and a receiver (Rx).
  • one or more antennas 616 may receive radio frequency signals
  • the receiver Rx of the transceiver 612 is configured to receive the radio frequency signals from the antennas, convert the radio frequency signals into digital baseband signals or digital intermediate frequency signals, and convert the digital
  • the baseband signal or digital intermediate frequency signal is provided to the processor 611, so that the processor 611 performs further processing on the digital baseband signal or digital intermediate frequency signal, such as demodulation processing and decoding processing.
  • the transmitter Tx in the transceiver 612 is used for receiving the modulated digital baseband signal or the digital intermediate frequency signal from the processor 611, and converting the modulated digital baseband signal or the digital intermediate frequency signal into a radio frequency signal, and passing through an or A plurality of antennas 616 transmit the radio frequency signals.
  • the receiver Rx can selectively perform one or more stages of down-mixing processing and analog-to-digital conversion processing on the radio frequency signal to obtain a digital baseband signal or a digital intermediate frequency signal. The order of precedence is adjustable.
  • the transmitter Tx can selectively perform one or more stages of up-mixing processing and digital-to-analog conversion processing on the modulated digital baseband signal or digital intermediate frequency signal to obtain a radio frequency signal, and the up-mixing processing and digital-to-analog conversion processing
  • the order of s is adjustable.
  • Digital baseband signals and digital intermediate frequency signals can be collectively referred to as digital signals.
  • the transmitter Tx and the receiver Rx may be implemented by different physical structures/circuits, or may be implemented by the same physical structure/circuit, that is, the transmitter Tx and the receiver Rx may be inherited together.
  • a transceiver may also be referred to as a transceiver unit, a transceiver, a transceiver, or the like.
  • the device used to implement the receiving function in the transceiver unit may be regarded as a receiving unit
  • the device used to implement the transmitting function in the transceiver unit may be regarded as a transmitting unit, that is, the transceiver unit includes a receiving unit and a transmitting unit, and the receiving unit also It can be called a receiver, an input port, a receiving circuit, etc.
  • the sending unit can be called a transmitter, a transmitter, or a transmitting circuit, etc.
  • a combination of Tx, Rx and antenna can be used as a transceiver.
  • Output device 614 displays information in a variety of ways.
  • the output device 614 may be a Liquid Crystal Display (LCD), a Light Emitting Diode (LED) display device, a Cathode Ray Tube (CRT) display device, or a projector (projector) Wait.
  • Input device 615 may accept user input in a variety of ways.
  • the input device 615 may be a mouse, a keyboard, a touch screen device, a sensor device, or the like.
  • FIG. 11 is a schematic structural diagram of an access network device provided by an embodiment of the present application, which may be a schematic structural diagram of an access network device by way of example, and the access network device may adopt a CU-DU separation architecture.
  • the base station can be applied to the system shown in FIG. 1 or FIG. 2 or FIG. 3 to implement the access network device (source access network device and/or target access network device) in the foregoing method embodiment. ) function.
  • An access network device may include one or more DUs 1101 and one or more CUs 1102.
  • the DU 1101 may include at least one antenna 11011, at least one radio frequency unit 11012, at least one processor 11013 and at least one memory 11014.
  • the DU 1101 part is mainly used for the transmission and reception of radio frequency signals, the conversion of radio frequency signals and baseband signals, and part of baseband processing.
  • the CU 1102 may include at least one processor 11022 and at least one memory 11021 . Communication between the CU 1102 and the DU 1101 may be performed through an interface, wherein the control plane (control plane) interface may be F1-C, and the user plane (user plane) interface may be F1-U.
  • control plane control plane
  • user plane user plane
  • the CU 1102 part is mainly used to perform baseband processing, control the base station, and the like.
  • the DU 1101 and the CU 1102 may be physically set together, or may be physically separated, that is, a distributed base station.
  • the CU 1102 is the control center of the base station, which can also be called a processing unit, and is mainly used to complete the baseband processing function.
  • the CU 1102 may be used to control the base station to execute the operation flow of the network device in the foregoing method embodiments.
  • the baseband processing on the CU and the DU may be divided according to the protocol layer of the wireless network, and the above content may be referred to for details.
  • the CU 1102 may be composed of one or more boards, and the multiple boards may jointly support a wireless access network (such as a 5G network) with a single access indication, or may respectively support a wireless access network with different access standards.
  • Wireless access network (such as LTE network, 5G network or other access network).
  • the memory 11021 and the processor 11022 may serve one or more single boards. That is to say, the memory and processor can be provided separately on each single board. It can also be that multiple boards share the same memory and processor. In addition, necessary circuits may also be provided on each single board.
  • the DU 1101 can be composed of one or more single boards, and multiple single boards can jointly support a wireless access network (such as a 5G network) with a single access indication, or can support a wireless access network with different access standards (such as a 5G network). Such as LTE network, 5G network or other access network).
  • the memory 11014 and processor 11013 may serve one or more single boards. That is to say, the memory and processor can be provided separately on each single board. It can also be that multiple boards share the same memory and processor. In addition, necessary circuits may also be provided on each single board.
  • the CU 1102 can transmit with the child node of the access network device through the DU 1101, the CU 1102 can be connected with other access network devices through the interface, and the CU 1102 can transmit from other access network devices (such as other access network devices) through the interface.
  • the CU of the network access device receives data and/or messages, or the CU 1102 can send data and/or messages to the other access network devices through the interface.
  • FIG. 12 is a schematic structural diagram of a communication device provided by an embodiment of the present application.
  • the communication device may be a relay node, and may implement the functions of a relay node (for example, an IAB node) in the above method embodiments; or the communication device may be It is an access network device, and can implement the functions of the source access network device or the target access network device in the above method embodiments.
  • Fig. 12 illustrates the main components of the communication device, as shown in Fig. 12:
  • the communication device includes at least one processor 711 , at least one memory 712 , at least one transceiver 713 , at least one network interface 714 and one or more antennas 715 .
  • the processor 711, the memory 712, the transceiver 713 and the network interface 714 are connected, for example, through a bus. In this embodiment of the present application, the connection may include various interfaces, transmission lines, or buses, which are not limited in this embodiment. .
  • Antenna 715 is connected to transceiver 713 .
  • the network interface 714 is used to connect the communication device with other network devices through a communication link.
  • the transceiver 713, the memory 712 and the antenna 716 can refer to the related description in FIG. 10 to achieve similar functions.
  • FIG. 13 is a schematic structural diagram of a communication device according to an embodiment of the present application.
  • the communication apparatus may execute the methods described in the foregoing method embodiments, and reference may be made to the descriptions of the foregoing method embodiments.
  • the communication device may be used in a communication device, circuit, hardware component or chip, for example, the communication device may be a terminal, a chip in a terminal, a host node (including a source host node or a target host node) or a host node (including a source host node or a target host node) host node).
  • the communication device 1300 includes a processing unit 1301 and a communication unit 1302 .
  • the communication device 1300 further includes a storage unit 1303 .
  • the processing unit 1301 may be a device with processing functions, and may include one or more processors.
  • the processor may be a general-purpose processor or a special-purpose processor, or the like.
  • the processor may be a baseband processor, or a central processing unit.
  • the baseband processor may be used to process communication protocols and communication data
  • the central processing unit may be used to control devices (eg, host nodes, terminals or chips, etc.), execute software programs, and process data of software programs.
  • the communication unit 1302 may be a device having signal input (reception) or output (transmission) for transmitting signals with other network devices or other devices in the device.
  • the storage unit 1303 may be a device with a storage function, and may include one or more memories.
  • processing unit 1301, the communication unit 1302 and the storage unit 1303 are connected through a communication bus.
  • the storage unit 1303 may exist independently and be connected to the processing unit 1301 through a communication bus.
  • the storage unit 1303 may also be integrated with the processing unit 1301 .
  • the communication apparatus 1300 may be a chip in a terminal or a host node in this embodiment of the present application.
  • the communication unit 1302 may be an input or output interface, a pin or a circuit, or the like.
  • the storage unit 1303 may be a register, a cache or a RAM, etc., and the storage unit 1303 may be integrated with the processing unit 1301; the storage unit 1303 may be a ROM or other types of static storage devices that can store static information and instructions, and the storage unit 1303 may The processing units 1301 are independent.
  • the transceiver may be integrated on the communication device 1300 , for example, the communication unit 1302 integrates the transceiver 612 shown in FIG. 10 .
  • the processing unit 1301 may include instructions, and the instructions may be executed on the processor, so that the communication apparatus 1300 executes the method of the terminal or the host node in the above embodiments.
  • the storage unit 1303 stores instructions, and the instructions can be executed on the processing unit 1301, so that the communication device 1300 executes the method of the terminal or the host node in the above embodiments.
  • the storage unit 1303 may also store data.
  • the processing unit 1301 may also store instructions and/or data.
  • the communication apparatus 1300 may be a terminal in this embodiment of the present application.
  • a schematic diagram of the terminal may be as shown in FIG. 10 .
  • the communication unit 1302 of the apparatus 1300 may include an antenna and a transceiver of the terminal, for example, the antenna and the transceiver in FIG. 10 .
  • the communication unit 1302 may further include an output device and an input device, for example, the output device and the input device in FIG. 10 .
  • the communication apparatus 1300 may be a terminal or a chip of the terminal in the embodiment of the present application, the communication apparatus 1300 may implement the functions implemented by the terminal in the foregoing method embodiments.
  • the communication apparatus 1300 may be a relay node or a chip of the relay node in the embodiment of the present application, the communication apparatus 1300 may implement the functions implemented by the relay node in the foregoing method embodiments.
  • the communication apparatus 1300 may be a chip of an access network device (for example, a source access network device or a target access network device) in this embodiment of the present application, the communication apparatus 1300 may implement the function of the host node in the foregoing method embodiments.
  • an access network device for example, a source access network device or a target access network device
  • the terminal may have functional units (means) corresponding to the methods or steps of the terminal, and the relay node may have functions corresponding to the methods or steps of the relay node.
  • the source host node eg CU and/or DU
  • the target host node eg CU and/or DU
  • the functional unit corresponding to the method or step of the target host node eg CU and/or DU
  • the CU of the source host node may have a functional unit corresponding to the method or step of the CU of the source host node
  • other nodes in the relay system There may be functional units corresponding to the other nodes.
  • One or more of the above modules or units may be implemented in software, hardware or a combination of both.
  • the software exists in the form of computer program instructions and is stored in the memory, and the processor can be used to execute the program instructions to implement the above method flow.
  • the processor in this application may include, but is not limited to, at least one of the following: a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), a microcontroller (MCU), or Artificial intelligence processors and other types of computing devices that run software, each computing device may include one or more cores for executing software instructions to perform operations or processing.
  • the processor can be a separate semiconductor chip, or can be integrated with other circuits into a semiconductor chip. on a chip), or it can be integrated in the ASIC as a built-in processor of an application-specific integrated circuit (ASIC). Other circuits are packaged together.
  • the processor may further include necessary hardware accelerators, such as field programmable gate arrays (FPGA), programmable logic devices (programmable logic devices), in addition to cores for executing software instructions for operation or processing. device, PLD), or a logic circuit that implements dedicated logic operations.
  • FPGA field programmable gate arrays
  • programmable logic devices programmable logic devices
  • PLD programmable logic circuit that implements dedicated logic operations.
  • the memory in this embodiment of the present application may include at least one of the following types: read-only memory (ROM) or other types of static storage devices that can store static information and instructions, random access memory (random access memory) , RAM) or other types of dynamic storage devices that can store information and instructions, and can also be electrically erasable programmable read-only memory (electrically erasable programmable read-only memory, EEPROM).
  • ROM read-only memory
  • RAM random access memory
  • EEPROM electrically erasable programmable read-only memory
  • the memory may also be compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.) , a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, without limitation.
  • CD-ROM compact disc read-only memory
  • optical disc storage including compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.
  • magnetic disk storage medium or other magnetic storage device or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, without limitation.
  • the bus may also include a power bus, a control bus, a status signal bus, and the like.
  • the various buses are labeled as buses in the figure.
  • each step of the above-mentioned method can be completed by a hardware integrated logic circuit in a processor or an instruction in the form of software.
  • the steps of the methods disclosed in conjunction with the embodiments of the present application may be directly embodied as executed by a hardware processor, or executed by a combination of hardware and software modules in the processor.
  • the software modules may be located in random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers and other storage media mature in the art.
  • the storage medium is located in the memory, and the processor reads the information in the memory, and completes the steps of the above method in combination with its hardware. To avoid repetition, detailed description is omitted here.
  • the embodiment of the present application further provides a system, which includes the foregoing apparatus and one or more than one network device.
  • the size of the sequence numbers of the above-mentioned processes does not mean the sequence of execution, and the execution sequence of each process should be determined by its functions and internal logic, and should not be dealt with in the embodiments of the present application. implementation constitutes any limitation.
  • the disclosed system, apparatus and method may be implemented in other manners.
  • the apparatus embodiments described above are only illustrative.
  • the division of the units is only a logical function division. In actual implementation, there may be other division methods.
  • multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented.
  • the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.
  • the above-mentioned embodiments it may be implemented in whole or in part by software, hardware, firmware or any combination thereof.
  • software it can be implemented in whole or in part in the form of a computer program product.
  • the computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated.
  • the computer may be a general purpose computer, special purpose computer, computer network, or other programmable device.
  • the computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be downloaded from a website site, computer, server, or data center Transmission to another website site, computer, server, or data center by wire (eg, coaxial cable, optical fiber, digital subscriber line, DSL) or wireless (eg, infrared, wireless, microwave, etc.).
  • the computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, or the like that includes an integration of one or more available media.
  • the usable media may be magnetic media (eg, floppy disks, hard disks, magnetic tapes), optical media (eg, digital versatile discs (DVDs)), or semiconductor media (eg, solid state drives), and the like.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Computer Security & Cryptography (AREA)
  • Radio Relay Systems (AREA)

Abstract

本申请提供了一种用于接入回传一体化IAB系统中的通信方法，其特征在于，该方法包括：子节点通过父节点接收来自接入网设备的第一无线资源控制RRC重配置消息，所述第一RRC重配置消息包括免随机接入的指示；所述子节点启动定时器；所述子节点通过所述父节点向所述接入网设备发送第一RRC重配置完成消息；所述子节点从所述父节点接收第一指示信息，所述第一指示信息指示停止所述定时器；所述子节点停止所述定时器。

Description

一种用于接入回传一体化IAB系统中的通信方法和通信装置 技术领域
本申请涉及无线通信技术领域，尤其涉及一种一种用于接入回传一体化IAB系统中的通信方法和通信装置。
背景技术
相较于第四代移动通信系统，第五代(fifth generation，5G)移动通信针对网络各项性能指标，全方位得都提出了更严苛的要求。例如，容量指标提升1000倍，更广的覆盖需求和超高可靠超低时延等。接入回传一体化(Integrated access and backhaul，IAB)系统应运而生，通过大量密集部署的节点，可以为终端提供灵活便利的接入和回传服务，提升覆盖范围，从而满足5G更为严苛的性能指标。
在诸如IAB系统等中继系统中，由于链路质量等原因，中继节点可能发生切换，中继节点的切换会对IAB系统中的其他节点或者终端造成影响，导致业务传输的中断，极大地降低了用户体验。
发明内容
本申请提供了一种应用于接入回传一体化IAB系统中的通信方法、通信装置和通信系统，可以在子节点的免随机接入的过程中，使得子节点及时停止定时器，避免因定时器超时导致切换失败，提高切换的成功率，降低切换的时延，保障切换的性能。
下面结合第一方面至第三方面描述本申请实施例提供的方案，需要说明的实，第一方面至第三方面从不同网元的角度描述了方案，其内容可以相互参考和引用。
本申请第一方面提供了一种应用于接入回传一体化IAB系统中的通信方法。该方法可以由子节点执行，或者可以由子节点中的芯片执行。下面以子节点执行为例进行介绍。该方法包括：子节点通过父节点接收来自接入网设备的第一无线资源控制RRC重配置消息，该第一RRC重配置消息包括免随机接入的指示；子节点接收到第一RRC重配置消息后，启动定时器；然后子节点通过父节点向接入网设备发送第一RRC重配置完成消息；子节点从父节点接收第一指示信息，该第一指示信息指示停止定时器；最后子节点根据该第一指示信息停止定时器。
通过父节点向子节点发送第一指示信息，子节点可以及时停止定时器，避免因定时器超时导致的切换失败和小区重选，减小切换的时延，保障切换后的通信性能。
在一种可能的实现方式中，第一指示信息可以通过明示或者暗示的方式指示停止定时器。下面介绍了两种暗示的方式。
可选的，第一指示信息为第一类型的媒体接入控制元素MAC CE，子节点在接收到第一类型的MAC CE后，就默认停止定时器。
或者，可选的，第一指示信息为携带竞争解决标识的MAC CE，该竞争解决标识可以是子节点的C-RNTI，或者可以是C-RNTI中的一个或者多个比特(bit)的数值， 或者该竞争解决标识可以是任意一个数值，本申请不作限制。子节点可以在解析出携带该竞争解决标识的MAC CE后，停止定时器。
在一种可能的实现方式中，子节点在收到第一RRC重配置消息前的小区无线网络临时标识C-RNTI，与收到第一RRC重配置消息后的小区无线网络临时标识C-RNTI可以相同。
可选的，第一RRC重配置消息不包括子节点的小区无线网络临时标识。
或者，可选的，第一RRC重配置消息包括第二指示信息，第二指示信息指示子节点的小区无线网络临时标识不变。
或者，可选的，第一RRC重配置消息包括子节点接收第一RRC重配置消息之前的使用的小区无线网络临时标识。
在一种可能的实现方式中，该方法还可以包括：父节点从接入网设备接收第三指示信息；然后，响应于第三指示信息，父节点向子节点发送第一指示信息。
可选的，第三指示信息包括子节点的标识。由于父节点可能具有多个子节点，通过第三指示信息包括子节点的标识，可以便于父节点知道给哪个子节点发送第一指示信息。
在一种可能的实现方式中，该接入网设备是子节点和父节点在群组切换过程中的目标接入网设备。可以理解，进行群组切换中的群组至少包括子节点和父节点，该群组还可以包括其他一个或者多个节点。在该群组切换中，子节点始终与父节点相连，也就是说，子节点的父节点没有发生变化。
在一种可能的实现方式中，方法还包括：父节点从接入网设备接收或者向子节点发送第一RRC重配置消息后，父节点接收来自接入网设备的第二RRC重配置消息，且父节点启动定时器。
由于父节点接收第二RRC重配置消息后，父节点可能会进行切换，从而停止与接入网设备之间的传输，通过父节点先从接入网设备接收或者向子节点发送第一RRC重配置消息，父节点再接收第二RRC重配置消息，可以保证父节点向子节点发送第一RRC重配置消息，保障子节点的切换的性能。
可选的，该方法还可以包括：父节点从接入网设备接收或者向子节点发送第一RRC重配置消息后，父节点向源接入网设备发送第四指示信息，用以触发源接入网设备向父节点发送第二RRC重配置消息，源接入网设备为子节点和父节点在群组切换过程中的源接入网设备。
可以理解，第二RRC重配置消息可以是目标接入网设备先发送给源接入网设备，由源接入网设备发送给父节点的，通过父节点向源接入网设备发送第四指示信息，可以确保父节点从接入网设备接收或者向子节点发送第一RRC重配置消息后，父节点再接收第二RRC重配置消息。
在一种可能的实现方式中，子节点为终端或者IAB节点，父节点为IAB节点。
在一种可能的实现方式中，接入网设备可以包括CU，可选的，接入网设备还可以包括DU。
本申请第二方面提供了一种应用于接入回传一体化IAB系统中的通信方法。该方法可以由父节点执行，或者可以由父节点中的芯片执行。下面以父节点执行为例进行介绍。该方法包括：父节点从接入网设备接收第一RRC重配置消息，第一RRC重配置消息包括免随机接入的指示；父节点向子节点发送第一RRC重配置消息，用以触发子节点启动定时器；父节点从子节点接收第一RRC重配置完成消息；父节点向接入网设备发送第一RRC重配置完成消息；父节点向子节点发送第一指示信息，第一指示信息指示停止定时器。
在一种可能的实现方式中，方法还包括：父节点从接入网设备接收第二指示信息；响应于第二指示信息，父节点向子节点发送第一指示信息。
可选的，第二指示信息包括子节点的标识。
在一种可能的实现方式中，第一指示信息为第一类型的媒体接入控制元素MAC CE，或者第一指示信息为携带竞争解决标识的MAC CE。
在一种可能的实现方式中，子节点在收到第一RRC重配置消息前的小区无线网络临时标识C-RNTI，与收到第一RRC重配置消息后的小区无线网络临时标识C-RNTI可以相同。
可选的，第一RRC重配置消息不包括子节点的小区无线网络临时标识。
或者，可选的，第一RRC重配置消息包括第三指示信息，第三指示信息指示子节点的小区无线网络临时标识不变。
或者，可选的，第一RRC重配置消息包括父节点向子节点发送第一RRC重配置消息之前，子节点的小区无线网络临时标识。
在一种可能的实现方式中，接入网设备是子节点在群组切换过程中的目标接入网设备。
在一种可能的实现方式中，方法还包括：父节点从接入网设备接收或者向子节点发送第一RRC重配置消息后，父节点接收来自接入网设备第二RRC重配置消息，且父节点启动定时器。
可选的，方法还包括：父节点从接入网设备接收或者向子节点发送第一RRC重配置消息后，父节点向源接入网设备发送第四指示信息，用以触发源接入网设备向父节点发送第二RRC重配置消息，源接入网设备为子节点和父节点在群组切换过程中的源接入网设备。
在一种可能的实现方式中，子节点为终端或者IAB节点，父节点为IAB节点。
在一种可能的实现方式中，接入网设备可以包括CU，可选的，接入网设备还可以包括DU。
本申请第三方面提供了一种应用于接入回传一体化IAB系统中的通信方法。该方法可以由接入网设备执行，或者可以由接入网设备中的芯片执行。下面以接入网设备 执行为例进行介绍。该方法包括：接入网设备通过父节点向子节点发送第一无线资源控制RRC重配置消息，用以触发子节点启动定时器，第一RRC重配置消息包括免随机接入的指示；接入网设备通过父节点从子节点接收第一RRC重配置完成消息；接入网设备向父节点发送第二指示信息，以触发父节点向子节点发送第一指示信息，第一指示信息指示停止定时器。
在一种可能的实现方式中，第二指示信息包括子节点的标识。
在一种可能的实现方式中，第一指示信息为第一类型的媒体接入控制元素MAC CE，或者第一指示信息为携带竞争解决标识的MAC CE。
在一种可能的实现方式中，子节点在收到第一RRC重配置消息前的小区无线网络临时标识C-RNTI，与收到第一RRC重配置消息后的小区无线网络临时标识C-RNTI可以相同。
可选的，第一RRC重配置消息不包括子节点的小区无线网络临时标识。
或者，可选的，第一RRC重配置消息包括第三指示信息，第三指示信息指示子节点的小区无线网络临时标识不变。
或者，可选的，第一RRC重配置消息包括接入网设备通过父节点向子节点发送第一RRC重配置完成消息之前，子节点的小区无线网络临时标识。
在一种可能的实现方式中，接入网设备是子节点在群组切换过程中的目标接入网设备。
可选的，方法还包括：目标接入网设备从源接入网设备接收切换请求消息，切换请求消息包括以下一项或者多项：切换前子节点的小区无线网络临时标识，切换前子节点接入的小区的标识和子节点在网络拓扑中的层级信息，源接入网设备为子节点和父节点在群组切换过程中的源接入网设备。
可选的，方法还包括：目标接入网设备根据层级信息确定定时器的时长；其中，第一RRC重配置消息包括定时器的时长的信息。
目标接入网设备接收子节点在网络拓扑中的层级信息，目标接入网设备可以根据该层级信息合理地确定定时器的时长，例如与迁移IAB节点之间的无线回传链路的跳数越大的节点，定时器的时长越大，与迁移IAB节点之间的无线回传链路的跳数越小的节点，定时器的时长越小。避免由于定时器的时长设置地不合理，而带来的子节点切换失败的情况。
本申请提供了一种应用于接入回传一体化IAB系统中的通信方法，可以使得子节点切换前后的C-RNTI保持不变，减少子节点配置C-RNTI的过程，降低子节点的功耗，节约电量。
下面结合第四方面和第五方面描述本申请实施例提供的方案，需要说明的实，第四方面至第五方面从不同网元的角度描述了方案，其内容可以相互参考和引用。
本申请第四方面提供了一种应用于接入回传一体化IAB系统中的通信方法。该方 法可以由子节点执行，或者可以由子节点中的芯片执行。下面以子节点执行为例进行介绍。方法包括：子节点通过父节点接收来自接入网设备的第一无线资源控制RRC重配置消息；子节点根据第一RRC重配置消息进行切换；其中，子节点切换前的小区无线网络临时标识与切换后的小区无线网络临时标识相同。
通过该子节点的C-RNTI保持不变，可以减少子节点配置C-RNTI的过程，降低子节点的功耗，节约子节点的电量。
在一种可能的实现方式中，子节点在收到第一RRC重配置消息前的小区无线网络临时标识C-RNTI，与收到第一RRC重配置消息后的小区无线网络临时标识C-RNTI可以相同。
可选的，第一RRC重配置消息不包括子节点的小区无线网络临时标识，或者第一RRC重配置消息包括第一指示信息，第一指示信息指示子节点的小区无线网络临时标识不变，或者第一RRC重配置消息包括子节点接收第一RRC重配置消息之前的使用的小区无线网络临时标识。
在一种可能的实现方式中，第一RRC重配置消息包括免随机接入的指示。
在一种可能的实现方式中，第四方面的方法还可以包括第一方面的方法，具体可以参考第一方法的内容。例如，方法还包括：子节点启动定时器；子节点通过父节点向接入网设备发送第一RRC重配置完成消息；子节点从父节点接收第二指示信息，第二指示信息指示停止定时器；子节点停止定时器。
在一种可能的实现方式中，子节点为终端或者IAB节点，父节点为IAB节点。
在一种可能的实现方式中，接入网设备可以包括CU，可选的，接入网设备还可以包括DU。
本申请第五方面提供了一种应用于接入回传一体化IAB系统中的通信方法。该方法可以由接入网设备执行，或者可以由接入网设备中的芯片执行。下面以接入网设备执行为例进行介绍。该方法包括：接入网设备获取第一无线资源控制RRC重配置消息；接入网设备通过父节点向子节点发送第一RRC重配置消息；其中，第一RRC重配置消息用于子节点的切换，子节点切换前的小区无线网络临时标识与切换后的小区无线网络临时标识相同。
在一种可能的实现方式中，子节点在收到第一RRC重配置消息前的小区无线网络临时标识C-RNTI，与收到第一RRC重配置消息后的小区无线网络临时标识C-RNTI可以相同。
可选的，第一RRC重配置消息不包括子节点的小区无线网络临时标识，或者第一RRC重配置消息包括第一指示信息，第一指示信息指示子节点的小区无线网络临时标识不变，或者第一RRC重配置消息包括子节点接收第一RRC重配置消息之前的使用的小区无线网络临时标识。
在一种可能的实现方式中，第一RRC重配置消息包括免随机接入的指示。
在一种可能的实现方式中，第五方面的方法还可以包括第三方面的方法，具体可以参考第三方面的方法。例如，第五方面的方法还可以包括：接入网设备通过父节点从子节点接收第一RRC重配置完成消息；接入网设备向父节点发送第二指示信息，以触发父节点向子节点发送第三指示信息，第三指示信息指示停止定时器。
本申请提供了一种方案，可以在群组切换的过程中，保证父节点先收到子节点的RRC重配置消息，再接收到父节点的RRC重配置消息，避免父节点先收到自己的RRC重配置消息后会停止与源接入网设备之间的传输，从而导致接收不到子节点的RRC重配置消息的情况，保障子节点的切换的功能。
下面结合第六方面和第七方面描述本申请实施例提供的方案，需要说明的实，第四方面至第五方面从不同网元的角度描述了方案，其内容可以相互参考和引用。
本申请第六方面提供了一种应用于接入回传一体化IAB系统中的通信方法。该方法可以由父节点执行，或者由父节点中的芯片执行。下面以父节点执行为例进行介绍。该方法包括：父节点从源接入网设备接收或者向子节点发送第一RRC重配置消息后，父节点从源接入网设备接收第二RRC重配置消息。
在一种可能实施方式中，该第一RRC重配置消息用于触发子节点开启定时器，该第二RRC重配置消息用于触发父节点开启定时器。
在一种可能的实现方式中，该源接入网设备可以是子节点和父节点在群组切换过程中的源接入网设备。
可选的，进行群组切换的群组中可以包括一个或者多个其他节点。
在一种可能的实现方式中，该方法还包括：父节点从源接入网设备接收或者向子节点发送第一RRC重配置消息后，父节点向源接入网设备发送第一指示信息，响应于第一指示信息，源接入网设备向父节点发送第一RRC重配置消息。
在一种可能的实现方式中，第六方面的方法可以包括第二方面的方法的内容。具体可以参考第二方面的方法的内容。
本申请第七方面提供了一种应用于接入回传一体化IAB系统中的通信方法。该方法可以由源接入网设备执行，或者由源接入网设备中的芯片执行。下面以源接入网设备行为例进行介绍。该方法包括：源接入网设备向父节点发送第一RRC重配置消息后，源接入网设备向父节点发送第二RRC重配置消息。
在一种可能实施方式中，该第一RRC重配置消息用于父节点的切换或者RRC重配置，可以称为父节点的RRC重配置消息，该第二RRC重配置消息用于子节点的切换或者重配置，可以称为子节点的RRC重配置消息。
在一种可能实施方式中，该第一RRC重配置消息用于触发子节点开启定时器，该第二RRC重配置消息用于触发父节点开启定时器。
在一种可能的实现方式中，该源接入网设备可以是子节点和父节点在群组切换过 程中的源接入网设备。
可选的，进行群组切换的群组中可以包括一个或者多个其他节点。
在一种可能的实现方式中，该方法还包括：源接入网设备向父节点发送第一RRC重配置消息后，源接入网设备从父节点接收第一指示信息，响应于第一指示信息，源接入网设备向父节点发送第二RRC重配置消息。
第六方面和第七方面的方法中第一RRC重配置消息和第二RRC重配置消息的内容可以参考上面第一方面至第五方面的内容。
本申请提供了一种方案，可以在群组切换的过程中，由源接入网设备将进行群组切换的群组中的一个或者多个节点的C-RNTI、接入的小区的小区标识和/或在网络拓扑中的层级信息发送给目标接入网设备。
下面结合第八方面和第九方面描述本申请实施例提供的方案，需要说明的实，第八方面至第九方面从不同网元的角度描述了方案，其内容可以相互参考和引用。
本申请第八方面提供了一种应用于接入回传一体化IAB系统中的通信方法。该方法可以由源接入网设备执行，或者由源接入网设备中的芯片执行。下面以源接入网设备执行为例进行介绍。该方法包括：源接入网设备获取切换请求消息，源接入网设备向目标接入网设备发送切换请求消息，包括一个或者多个节点的C-RNTI，接入的小区的小区标识和/或在网络拓扑中的层级信息。
通过源接入网设备向目标接入网设备发送一个或者多个节点的C-RNTI，便于目标接入网设备将每个节点的C-RNTI携带在RRC重配置消息中发送给该节点，从而该节点的C-RNTI在切换前和切换后可以保持不变，减少配置C-RNTI的过程，降低节点的功耗。
通过源接入网设备向目标接入网设备发送一个或者多个节点接入的小区的标识和C-RNT，可以便于目标接入网设备唯一地标识该一个或者多个节点。
可选的，该接入的小区的小区标识可以包括物理小区标识(physical cell identifier，PCI)，NR小区标识(NR Cell Identity，NCI)，NR小区全球标识(NR cell global identifier，NCGI)，E-UTRAN小区全球标识(E-UTRAN cell global identifier，ECGI)中的一种或者多种。
可选的，切换前后小区的PCI可以不变，NCGI和ECGI可以改变。
通过源接入网设备向目标接入网设备发送一个或者多个节点在网络拓扑中的层级信息，可以便于目标接入网设备可以根据该层级信息合理地确定定时器的时长，例如与迁移IAB节点之间的无线回传链路的跳数越大的节点，定时器的时长越大，与迁移IAB节点之间的无线回传链路的跳数越小的节点，定时器的时长越小。避免由于定时器的时长设置地不合理，而带来的子节点切换失败的情况。
在一种可能的实现方式中，该源接入网设备是该一个或者多个节点在群组切换过 程中的源接入网设备，该目标接入网设备是该一个或者多个节点在群组切换过程中的目标接入网设备。
在一种可能的实现方式中，该一个或者多个节点在网络拓扑中层级信息用于确定该一个或者多个节点的定时器的时长的信息。
在一种可能的实现方式中，该方法还包括：源接入网设备从目标接入网设备接收该一个或者多个节点各自的RRC重配置消息，源接入网设备向该一个或者多个节点中的每个节点发送该节点的RRC重配置消息，每个节点的RRC重配置消息包括该点的定时器的时长的信息。可以理解，源接入网设备向每个节点发送该节点的RRC重配置消息具体可以包括源接入网设备先向该节点的父节点发送该节点的RRC重配置消息，父节点再向该节点发送该RRC重配置消息。
在一种可能的实现方式中，第八方面的方法还可以包括第七方面的方法，可以理解，第七方面的子节点和父节点可以为第八方面的方法中的一个或者多个节点。
本申请第九方面提供了一种应用于接入回传一体化IAB系统中的通信方法。该方法可以由目标接入网设备执行，或者由目标接入网设备中的芯片执行。下面以目标接入网设备执行为例进行介绍。该方法包括：目标接入网设备从源接入网设备接收切换请求消息，包括一个或者多个节点的C-RNTI，接入的小区的小区标识和/或在网络拓扑中的层级信息。
在一种可能的实现方式中，该源接入网设备是该一个或者多个节点在群组切换过程中的源接入网设备，该目标接入网设备是该一个或者多个节点在群组切换过程中的目标接入网设备。
在一种可能的实现方式中，目标接入网设备根据层级信息确定一个或者多个节点各自的定时器的时长信息。
在一种可能的实现方式中，该方法还包括：目标接入网设备获取一个或者多个节点各自的RRC重配置消息，目标接入网设备向源接入网设备发送该一个或者多个节点各自的RRC重配置消息，源接入网设备向该一个或者多个节点中的每个节点发送该节点的RRC重配置消息，每个节点的RRC重配置消息包括该节点的定时器的时长的信息。
在一种可能的实现方式中，第九方面的方法还可以包括第三方面的方法，在此不再描述。例如，方法还包括：目标接入网设备接收每个节点的RRC重配置消息，且目标接入网设备接收每个节点的RRC重配置消息后，向该节点的父节点发送指示信息，以触发该父节点指示该节点停止定时器。
在一种可能的实现方式中，第九方面的方法还可以包括第五方面的方法，在此不再描述。例如，每个节点在切换前后的小区无线网络临时标识保持不变。
本申请第十方面提供了一种应用于接入回传一体化IAB系统中的通信方法。该方 法可以由目标接入网设备执行，或者由目标接入网设备中的芯片执行。下面以目标接入网设备执行为例进行介绍。该方法包括：目标接入网设备获取群组切换命令，所述组切换命令包括以下一项或者多项：免随机接入的指示信息，切换定时器的时长和服务小区的公共配置信息中的一种或者多种；目标接入网设备广播群组切换命令。
在一种可能的实现方式中，该目标接入网设备是群组切换过程中的目标接入网设备。进行群组切换的群组可以包括一个或者多个节点，相应地，该一个或者多个节点可以获取该群组切换命令。
通过将每个节点相同的信息通过广播的方式发送，可以节省空口的信令开销。尤其在IAB系统中，通过上述广播的方式，可以避免向群组中的多个节点单独发送信令带来的信令开销。
在一种可能的实现方式中，第十方面的方法还可以包括第三方面、第五方面和/或第九方面的方法，在此不再描述。
本申请第十一方面提供一种通信方法，可以应用于单空口的场景。终端从源接入网设备切换到目标接入网设备，目标接入网设备包括CU和DU，该方法可以包括：CU向DU发送第一指示信息，以触发DU向终端发送第二指示信息，终端根据该第二指示信息停止定时器。
在一种可能的实现方式中，CU向DU发送第一指示信息之前，该方法还可以包括：目标CU通过源接入网设备向终端发送第一RRC重配置消息，终端收到第一RRC重配置消息启动定时器，终端向DU发送第一RRC重配置完成消息，DU向CU发送第一RRC重配置完成消息。
可选的，第十一方面中的第一指示信息可以参考第一方面中的第二指示信息的内容，第十一方面中的第二指示信息可以参考第一方面中的第一指示信息的内容，在此不再描述。
上述第一方面至第十一方面中的一个或者多个方法可以相互结合，并且在每个方面的方法中，多种可能的实现方式中一种或者多种实现方式可以相互结合。
本申请实施例第十二方面提供了一种通信装置，该通信装置可以是子节点或者子节点中的芯片，或者该通信装置可以是父节点或者父节点中的芯片，或者该通信装置可以是源接入网设备或者源接入网设备中的芯片，或者该通信装置可以是目标接入网设备或者目标接入网设备中的芯片，或者该通信装置可以是CU或者CU中的芯片，或者该通信装置可以是DU或者DU中的芯片。该通信装置包括处理器，该处理器用于执行计算机程序或指令，使得该通信装置执行第一方面至第十一方面的方法。
可选的，该通信装置还包括该存储器。该处理器与存储器耦合，该存储器用于存储计算机程序或指令，该处理器用于执行该存储器中的计算机程序或指令。
可选的，该通信装置还可以包括通信单元，该通信单元用于与其他设备或者该通信装置中的其他组件通信。例如，该通信装置是子节点或者父节点，该通信单元为收发器。例如，该通信装置是接入网设备，该通信单元可以包括收发器和接入网设备之间的接口，该收发器用于接入网设备与接入网设备的子节点进行通信，该接口用于接 入网设备与其他接入网设备之间的通信。例如，该通信装置是CU，该通信单元为CU与DU之间的接口，以及该CU与其他接入网设备之间的接口。例如，该通信装置是DU，该通信单元为CU与DU之间的接口，以及该DU的收发器。
例如，该通信装置芯片，该通信单元为芯片的输入/输出电路或者接口。
本申请实施例第九方面提供了一种通信装置，该通信装置具有实现上述方法方面中子节点、父节点、源接入网设备、目标接入网设备、源接入网设备或者目标接入网设备的CU、源接入网设备或者目标接入网设备的DU的行为的功能，其包括用于执行上述第一方面至第十一方面的方法方面所描述的步骤或功能相对应的部件(means)。该步骤或功能可以通过软件实现，或硬件实现，或者通过硬件和软件结合来实现。
本申请实施例第十三方面提供了一种芯片，该芯片包括处理器和接口电路，该接口电路和该处理器耦合，该处理器用于运行计算机程序或指令，以实现如第一方面至第十一方面中任一方面的方法，该接口电路用于与该芯片之外的其它模块进行通信。
本申请实施例第十四方面提供了一种计算机存储介质，存储有用于实现上述第一方面至第十一方面中任一方面的方法的程序。当该程序在无线通信装置中运行时，使得该无线通信装置执行第一方面至第十一方面中任一方面的方法。
本申请实施例第十五方面提供了一种计算机程序产品，该程序产品包括程序，当该程序被运行时，使得上述第一方面至第七方面中任一方面的方法被执行。
本申请实施例第十六方面提供了一种通信系统，包括上述第一方面至第十一方面的方法中涉及的子节点、父节点、源接入网设备和目标接入网设备的一个或者多个。
附图说明
为了更清楚地说明本申请实施例或背景技术中的技术方案，下面将对本申请实施例或背景技术中所需要使用的附图进行说明。
图1是本申请实施例提供的一种移动通信系统100的示意图；
图2是本申请实施例提供的CU-DU的分离架构的示意图；
图3是本申请实施例提供的接入回传一体化(integrated access and backhaul node，IAB)网络的示意图；
图4A是本申请实施例提供的单空口的控制面协议栈的示意图；
图4B是本申请实施例提供的单空口的用户面协议栈的示意图；
图5A是本申请实施例提供的IAB网络中的控制面协议栈的示意图；
图5B是本申请实施例提供的IAB网络中的用户面协议栈的示意图；
图6是本申请实施例提供的群组切换的示意图；
图7是本申请实施提供的一种通信方法；
图8是本申请实施例提供的一种群组切换的方法；
图9是本申请实施例提供的另一种通信方法；
图10是本申请实施例提供的一种终端的结构示意图；
图11是本申请实施例提供的一种接入网设备的结构示意图；
图12是本申请实施例提供的一种通信装置的结构示意图；
图13为本申请实施例提供的一种通信装置的结构示意图。
具体实施方式
下面结合本申请实施例中的附图对本申请的实施例进行描述。
图1是本申请实施例提供的一种通信系统100的架构示意图。通信系统100包括至少一个终端(例如，终端110，终端120和终端130)、至少一个中继节点140(relay node，RN)、至少一个接入网设备150以及至少一个核心网设备160。
其中，终端可以与至少一个接入网设备相连，或者终端可以通过至少一个中继节点与至少一个接入网设备相连，该至少一个接入网设备与至少一个核心网设备相连。如图1所示，终端110和终端120均与中继节点140相连，中继节点140与接入网设备150相连，终端130与接入网络设备150相连。接入网设备150与核心网设备160连接。终端110，终端120，终端130，中继节点140，接入网设备150，以及核心网设备160之间的连接方式可以是无线或者有线，本申请中并不限定。
本申请提供的通信系统例如可以是支持4G接入技术的长期演进(long term evolution，LTE)系统，5G接入技术的新无线(new radio，NR)系统，任何与第三代合作伙伴计划(3rd generation partnership project，3GPP)相关的蜂窝系统，无线保真(wireless-fidelity，WiFi)系统，全球微波互联接入(worldwide interoperability for microwave access，WiMAX)系统，多无线接入技术(Radio Access Technology,RAT)系统，或者其他面向未来的通信技术。本申请中终端是具有无线收发功能的设备，可以部署在陆地上，包括室内或室外、手持、穿戴或车载；也可以部署在水面上(如轮船等)；还可以部署在空中(例如无人机、飞机、气球和卫星上等)。终端可以是手机(mobile phone)、平板电脑(Pad)、带无线收发功能的电脑、虚拟现实(virtual reality，VR)终端设备、增强现实(augmented reality，AR)终端设备、工业控制(industrial control)中的无线终端、无人驾驶(self driving)中的无线终端、远程医疗(remote medical)中的无线终端、智能电网(smart grid)中的无线终端、运输安全(transportation safety)中的无线终端、智慧城市(smart city)中的无线终端、智慧家庭(smart home)中的无线终端等等。本申请的实施例对应用场景不做限定。终端有时也可以称为终端设备、用户设备(user equipment，UE)、接入终端设备、站、UE单元、UE站、移动站、移动台、远方站、远程终端设备、移动设备、UE终端设备、终端设备、无线通信设备、UE代理或UE装置、或某种其他合适的术语。终端也可以是固定的或者移动的。
接入网设备可以是接入网侧用于支持终端接入通信系统的设备，接入网设备可以称为基站(base station，BS)，例如，4G接入技术通信系统中的演进型基站(evolved nodeB，eNB)，5G接入技术通信系统中的下一代基站(next generation nodeB，gNB)，收发点(transmission reception point，TRP)，中继节点(relay node)，接入点(access point，AP)，WiFi系统中的接入节点，无线回传节点等等，或者接入网设备可以称为宿主节点、IAB宿主(IAB donor)、宿主IAB、宿主或宿主gNB(DgNB，donor gNB)等。基站可以是：宏基站，微基站，微微基站，小站，中继站等。多个基站可以支持上述提及的同一种技术的网络，也可以支持上述提及的不同技术的网络。基站可以包含一个或多个共站或非共站的传输接收点(Transmi ssion receiving point,TRP)。接入网设备还可以是云无线接入网络(cloud radio access network，CRAN)场景下的 无线控制器、集中单元(central unit，CU)，和/或分布单元(distributed unit,DU)。接入网设备还可以是服务器，可穿戴设备，或车载设备等。以下以接入网设备为基站为例进行说明。通信系统中的多个接入网设备可以为同一类型的基站，也可以为不同类型的基站。基站可以与终端进行通信，也可以通过中继站与终端设备进行通信。终端可以与不同技术的多个基站进行通信，例如，终端可以与支持LTE网络的基站通信，也可以与支持5G网络的基站通信，还可以支持与LTE网络的基站以及5G网络的基站的双连接。
核心网设备可以连接一个或者多个接入网设备，可以为系统中的终端提供会话管理、接入认证、互联网协议(Internet Protocol，IP)地址分配和数据传输中的一种或者多种功能。例如核心网设备可以是4G接入技术通信系统中的移动管理实体(mobile management entity，MME)或者服务网关(serving gateway，SGW)，5G接入技术通信系统中的接入和移动性管理功能(Access and Mobility Management Function，AMF)网元或者用户面性能(User Plane Function，UPF)网元等等。核心网设备也可以称为核心网网元。
中继节点可以是提供无线接入服务和/或回传服务的节点。无线接入服务是指通过无线接入链路提供数据和/或信令，无线回传服务是指通过无线回传链路提供的数据和/或信令回传服务。中继节点用于实现终端和接入网设备之间的数据和/或信令的转发。中继节点一方面通过接入链路(access link，AL)为终端提供无线接入服务，另一方面通过一跳或者多跳回传链路(backhaul link，BL)连接到接入网设备。
中继节点在不同的通信系统中可以有不同的名称，例如，中继节点可以称为无线回传节点或者无线回传设备。例如，在5G系统中，中继节点可以称为接入回传一体化节点(integrated access and backhaul node，IAB node)。当然，在未来的通信系统中，中继节点还可以有不同的名称，在此不作限制。
可选的，中继节点也可以是由终端设备充当的。或者，中继节点还可以是家庭接入场景的CPE。示例性的，IAB节点可以是用户驻地设备(customer premises equipment，CPE)或者家庭网关(residential gateway，RG)等设备。该情况下，本申请实施例提供的方法还可以应用于家庭连接(home access)的场景中。
图2是本申请实施例提供的CU-DU的分离架构的示意图。图1中的接入网设备150可以采用CU-DU的分离架构，图2以接入网设备为gNB(new radio nodeB，gNB)为例进行说明。
gNB可以通过云无线接入网(cloud radio access network，C-RAN)架构来实现，gNB的一部分功能由集中单元(central unit，CU)实现，另一部分功能又分布单元(distributed unit，DU)实现。CU和DU的切分可以按照协议栈切分，其中一种可能的方式是将无线资源控制(radio resource control，RRC)层、服务数据映射协议(service data adaptation protocol，SDAP)层以及分组数据汇聚协议(packet data convergence protocol，PDCP)层部署在CU，其余的无线链路控制(radio link control，RLC)层、媒体接入控制(media access control，MAC)层以及物理(physical，PHY)层部署在DU。
一个CU可以连接一个DU或者多个DU，从而易于网络扩展。CU和DU通过接 口相连(例如F1接口)，CU和核心网(例如5G核心网(5G core network，5GC))之间通过接口相连(例如NG接口)。
在一种实现方式中，CU包括用户面(User plane，简称UP)(本申请中简称为CU-UP)和控制面(Control plane，简称CP)(本申请中简称为CU-CP)。
图3是本申请实施例提供的接入回传一体化(integrated access and backhaul node，IAB)网络的示意图。图3为图1所示的通信系统100下的一种应用场景，下面结合图3，对图1中的终端、中继节点和接入网设备做进一步的说明。
IAB网络包括一个或者多个终端(清楚起见，图3中仅示出终端1)，一个或者多个IAB节点(清楚起见，图2中示出了2个IAB节点，即IAB node 1和IAB node 2)，以及一个或者多个宿主节点(清楚起见，图2中仅示出IAB donor 1)。
其中，终端1可以与一个或者多个IAB节点连接，每个IAB节点可以与一个或者多个其他IAB节点连接，一个或者多个IAB节点可以与一个或者多个宿主节点连接。可选的，一个或者多个IAB节点还可以彼此相互连接，本申请并不限定。
IAB donor可以称为宿主节点(donor node)、DgNB(即donor gNodeB)或其他合适的名字，本申请对此不做限定。
在图3中，终端1可以为图1中的终端110。IAB node(节点)1和IAB node 2可以为图1中的中继节点140。IAB donor 1可以为图1中的接入网设备150。5G核心网(5G Core Network，5GC)和演进型分组核心网(evolved packet core，EPC)可以为图1中的至少一个核心网设备组成的核心网。
图3中的IAB donor 1可以为图2中的gNB，IAB donor 1可以采用图2中的CU-DU的分离架构，也就是说，IAB donor 1可以由集中单元(可以称为IAB donor CU 1)和分布单元(可以称为IAB donor DU 1)组成，IAB donor CU 1可以由CP(可以称为IAB donor CU 1-CP)和UP(可以称为IAB donor CU 1-UP)组成，具体可以参考图2中的内容。
IAB网络支持独立组网(standalone，SA)或者非独立组网(non-standalone，NSA)的组网方式。
例如，图3的SA的组网方式中，IAB donor 1可以与5GC相连，具体地，IAB donor CU 1-CP可以与5GC中的控制面网元，例如接入和移动性管理功能(access and mobility management function，AMF)相连，IAB donor CU 1-UP可以与5GC中的用户面网元，例如用户面功能(user plane function，UPF)相连。
例如，图3的NSA的组网方式中，IAB donor 1作为辅gNB(secondary gNB，SgNB)，与主eNB(master eNB，MeNB)建立双连接，其中，IAB node 1和IAB node 2均与MeNB相连，IAB donor CU 1-CP与MeNB相连，MeNB与EPC相连，IAB donor CU 1-UP与EPC中的网元，例如业务网关(serving gateway，SGW)相连。
可以理解的是，在IAB网络中，终端和宿主节点之间的一条传输路径上，可以包含一个或多个IAB节点。若一个IAB节点是终端接入的节点，该IAB节点和子节点(即终端)之间的链路可以称为接入链路。若一个IAB节点是为其他IAB节点下的终端提供回传服务的节点，该IAB节点和子节点(即其他IAB节点)之间的链路可 以称为回传链路。例如，如图3中，终端1通过无线接入链路与IAB node 1相连，IAB node 1通过无线回传链路与IAB node 2相连，IAB node 2通过无线回传链路与IAB donor 1相连。
为了保证业务传输的可靠性，可选的，IAB网络支持多跳IAB节点和多连接IAB节点组网。在终端和IAB宿主之间可能存在多条传输路径。在一条路径上，IAB节点之间，以及IAB节点和为IAB节点服务的宿主节点有确定的层级关系，每个IAB节点或者终端将为该IAB节点或者终端提供接入服务的节点视为父节点。相应地，每个IAB节点或者终端可视为其父节点的子节点。
此外，本申请实施例中将IAB节点的父节点的父节点称为该IAB节点的祖父节点，将IAB节点的子节点的子节点视为该IAB节点的孙节点。
可以理解，父节点和子节点是相对的概念，某个节点相对一个节点可以是子节点，相对另一个节点可以是父节点。例如，图3中，IAB node 1为终端1的父节点，终端1为IAB node 1的子节点；IAB node 2为IAB node 1的父节点，IAB node 1为IAB node 2的子节点；IAB donor 1(具体可以为IAB donor DU)为IAB node 2的父节点，IAB node 2为IAB donor 1(具体可以为IAB donor DU)的子节点。
终端的上行数据包可以经过一个或多个IAB节点传输至宿主节点后，再由宿主节点发送至核心网设备，例如移动网关设备(例如5G网络中的用户面功能(user plane function，简称UPF)网元)。终端的下行数据包将由宿主节点从核心网设备移动网关设备处接收后，再经过一个或多个IAB节点发送至终端。
例如，图3中，终端1和IAB donor 1之间的上行数据包的传输路径为：终端1→IAB node 1→IAB node 2→IAB donor 1，终端1和IAB donor 1之间的下行数据包的传输路径为：IAB donor 1→IAB node 2→IAB node 1→终端1。
在IAB网络中，在一条传输路径上，可以将终端接入的IAB节点称为接入IAB节点，该条传输路径上的其他IAB节点称为中间IAB节点。中间IAB节点可以为终端提供回传服务。一个IAB节点既可以作为某个终端的接入IAB节点，也可以作为其他终端的中间IAB节点。
例如，图3中，在路径“终端1→IAB node 1→IAB node 2→IAB donor 1”上，IAB node 1为接入IAB节点，IAB node 2为中间IAB节点。若终端2(图2中未示出)接入IAB node 3(图3中未示出)，IAB node 3接入IAB node 1，那么对终端2而言，IAB node 3是接入IAB节点，IAB node 1是中间IAB节点。
在IAB网络中，可以将IAB节点服务的一个或者多个IAB节点和一个或者多个终端称为该IAB节点的后代(descendant)节点，可以理解，后代节点可以包括该IAB节点服务的IAB节点，或者可以理解，后代节点包括至少通过一跳链路连接到该IAB节点的下属IAB节点，例如后代节点包括子节点和孙节点等等，以及接入这些IAB节点的终端，例如包括接入子节点和孙节点等的终端。
例如，图3中，IAB node 2的后代节点包括终端1和IAB node 1。
上述IAB网络仅仅是示例性的，在多跳和多连接结合的IAB网络中，IAB网络还有更多其他的可能性，例如，宿主节点和另一宿主节点下的IAB节点组成双连接为终端服务等，此处不再一一列举。
IAB网络中，对于IAB节点而言，IAB节点作为父节点时，可以充当一个类似接入网设备的角色，为其子节点提供接入服务，例如：可以通过调度为其子节点分配用于传输上行数据的上行资源。IAB节点作为子节点时，对于为该IAB节点提供服务的父节点而言可以充当一个终端设备的角色，例如通过小区选择、随机接入等操作，与父节点建立连接，获取父节点为其调度的用于传输上行数据的上行资源。
作为示例而非限定，本申请实施例将IAB节点中支持IAB节点实现终端设备的角色的功能单元称为IAB节点的移动终端(mobile terminal，MT)功能单元，简称为IAB-MT或者IAB-UE，将IAB节点中支持IAB节点实现接入网设备的角色的功能单元称为IAB节点的DU功能单元，简称为IAB-DU。IAB-MT和IAB-DU可以是一种逻辑功能单元，其功能均由IAB节点实现；或者IAB-MT和IAB-DU可以是一种物理的划分，IAB-MT和IAB-DU可以是IAB节点中的不同的物理设备。
例如，图3中，IAB node 1包括MT功能单元和DU功能单元，IAB node 2包括MT功能单元和DU功能单元。
图4A和图4B分别是本申请实施例提供的单空口的控制面协议栈的示意图和用户面协议栈的示意图。
单空口可以理解为终端直接与接入网设备相连，而不需要通过中继节点与接入网设备相连。图4A和图4B中的UE可以为图1中的终端130，图4A和图4B中的gNB可以为图1中的接入网设备150，可以采用图2所示的CU-DU的分离架构。
单空口场景中，UE可以通过DU接入CU，其中，与UE对等的RLC层、MAC层和PHY层的功能由DU实现，与UE对应的RRC层、SDAP层和PDCP层的能由CU实现。
对于控制面而言，如图4A所示，UE与CU之间建立有对等的RRC层和PDCP层。UE与DU通过接口相连(例如Uu接口)，UE与DU之间建立有对等的RLC层、MAC层和PHY层；DU与CU之间通过控制面接口相连(例如F1控制面F1-control plane，F1-C接口)，DU与CU之间建立有对等的F1应用协议(F1application protocol，F1AP)层、流控制传输协议(stream control transmission protocol，SCTP)层、互联网协议(Internet Protocol，IP)层、层(layer，L)2和层(layer，L)1。
对于用户面而言，如图4B所示，UE与CU之间建立有对等的SDAP层和PDCP层。UE与DU通过Uu接口连接，UE与DU之间建立有对等的RLC层、MAC层和PHY层；DU与CU之间通过F1用户面(F1-user plane，F1-U)接口连接，DU与CU之间建立有对等的通用分组无线服务(general packet radio service，GPRS)隧道协议用户面(GPRS tunneling protocol-user plane，GTP-U)层、用户数据报协议(user datagram protocol，UDP)层、IP层、L2和L1。
图5A和图5B分别是本申请实施例提供的IAB网络中的控制面协议栈的示意图和用户面协议栈的示意图，图5A和图5B以图3中的场景为例进行说明。
IAB网络中，与终端对等的PHY层、MAC层和RLC层位于接入IAB节点上，而与UE对等的PDCP层、SDAP层和RRC层位于IAB donor CU上，若IAB donor-CU由CP和UP组成，则与UE对等的RRC层位于IAB donor CU的CP(即donor-CU-CP) 上，UE对等的PDCP层和SDAP层位于IAB donor CU的UP(即donor-CU-UP)上。
对于控制面而言，如图5A所示，终端1和IAB node 1的DU之间建立有Uu接口，对等的协议层包括RLC层、MAC层和PHY层。IAB node 1的DU和IAB donor CU1建立有F1-C接口，对等的协议层包括F1AP层、SCTP层和IP层。IAB donor DU 1和IAB donor CU 1之间建立有IAB宿主内的F1接口，对等的协议层包括IP层、L2和L1。IAB node 1和IAB node 2之间，以及IAB node 2和IAB donor DU 1之间均建立有BL，对等的协议层包括回传适配协议(Bakhaul Adaptation Protocol，BAP)层、RLC层、MAC层以及PHY层。另外，终端1和IAB donor CU 1之间建立有对等的RRC层和PDCP层，IAB node 1的DU和IAB donor DU 1之间建立有对等的IP层。
本申请实施例中，BAP层包括以下一种或多种能力：为数据包添加能被无线回传节点(IAB节点)识别出的路由信息(routing information)、基于所述能被无线回传节点识别出的路由信息执行路由选择、为数据包添加能被无线回传节点识别出的与服务质量(quality of service，QoS)需求相关的标识信息、为数据包执行在包含无线回传节点的多段链路上的QoS映射、为数据包添加数据包类型指示信息、向具有流量控制能力的节点发送流控反馈信息。需要说明的是，具备这些能力的协议层的名称不一定为BAP层，也可以为其它名称。本领域技术人员可以理解，只要具备这些能力的协议层均可以理解为本申请实施例中的BAP层。
可以看出，IAB网络的控制面协议栈与单空口的控制面协议栈相比，接入IAB节点的DU实现了单空口的gNB的DU的功能，即与终端建立对等RLC层、MAC层和PHY层的功能，以及与CU建立对等的F1AP层、SCTP层和IP层的功能。IAB donor CU实现了单空口的gNB的CU的功能。
对于用户面而言，如图5B所示，终端1和IAB node 1的DU之间建立有Uu接口，对等的协议层包括RLC层、MAC层和PHY层。IAB node 1的DU和IAB donor CU1建立有F1-U接口，对等的协议层包括GTP-U层、UDP层和IP层。IAB donor DU 1和IAB donor CU 1之间建立有IAB宿主内的F1接口，对等的协议层包括IP层、L2和L1。IAB node 1和IAB node 2之间，以及IAB node 2和IAB donor DU 1之间均建立有BL，对等的协议层包括BAP层、RLC层、MAC层以及PHY层。另外，终端1和IAB donor CU 1之间建立有对等的SDAP层和PDCP层，IAB node 1的DU和IAB donor DU 1之间建立有对等的IP层。
可以看出，IAB网络的用户面协议栈与单空口的用户面协议栈相比，IAB接入节点的DU实现了单空口的gNB的DU的部分功能，即与终端建立对等RLC层、MAC层和PHY层的功能，以及与IAB donor CU 1建立对等的GTP-U层、UDP层和IP层的功能。IAB donor CU实现了单空口的gNB的CU的功能。
图5A和图5B仅以图3所示的IAB场景下的协议栈为例进行了描述。需要说明的是，一个IAB节点可能具备一个或者多个角色，该IAB节点可以拥有该一个或者多个角色的协议栈；或者，IAB节点可以具有一套协议栈，该协议栈可以针对IAB节点的不同角色，使用不同角色对应的协议层进行处理。下面以该IAB节点拥有该一个或者多个角色的协议栈为例进行说明：
(1)终端的协议栈
IAB节点在开始接入IAB网络时或者接入IAB网络后，可以充当终端的角色，该IAB节点的MT具有终端的协议栈，例如图5A和图5B中的终端1的协议栈。该IAB节点可以与IAB donor传输自己的上行和/或下行的数据包(例如OAM数据包)，通过RRC层执行测量等等。
(2)接入IAB节点的协议栈
IAB节点在接入IAB网络后，该IAB节点可以为终端提供接入服务，从而充当一个接入IAB节点的角色，此时，该IAB节点具有接入IAB节点的协议栈，例如图5A和图5B中的IAB node 1的协议栈。
(3)中间IAB节点的协议栈
IAB节点在接入IAB网络后，该IAB节点可以充当一个中间IAB节点的角色，此时，该IAB节点具有中间IAB节点的协议栈，例如图5A和图5B中的IAB node 2的协议栈。
IAB节点可以拥有上述终端、接入IAB节点和中间IAB节点中的一个或者多个角色的协议栈。
图6是本申请实施例提供的群组切换的示意图。下面结合图6进行说明。
图6中，IAB node 1可以为一个或者多个终端和/或者其他IAB节点提供接入和/或回传服务，为了便于描述，可以将该一个或者多个终端和/或其他IAB节点称为后代节点或者下属节点。清楚起见，图6示意出了IAB node 1与终端1和IAB node 4相连，IAB node 3与终端2相连，其中，IAB node 1为终端1和IAB node 4提供接入服务，IAB node 4为终端2提供接入服务，IAB node 1为终端2提供回传服务。需要说明的是，在实际网络部署场景中，IAB node 1还可能具有一个或者多个孙节点，IAB node 4可以为更多的终端或者IAB node提供接入和/或回传服务，本申请实施例对此不做限制。
由于链路质量或者负载变化等原因，IAB node 1可以发生切换。IAB node 1从IAB node 2切换至IAB node 3(或者说IAB node 1从IAB node 2服务的小区切换连接至IAB node 3服务的小区)，IAB node 2与IAB donor 1相连，IAB node 3与IAB donor 2相连。
由于IAB node 1在切换前和切换后连接的IAB donor发生了变化，可以将IAB node1的切换称为跨宿主节点的切换。
首先，IAB node 1可以以一个终端的角色从IAB node 2切换至IAB node 3。另外，由于IAB node 1还服务于后代节点，这些后代节点可以跟随着IAB node 1一起从连接到IAB node 2变化为连接至IAB node 3，由于后代节点的宿主节点也发生了变化，可以认为后代节点同样发生了切换。可以将IAB node 1和后代节点称为一个群组，将IAB node 1和后代节点的切换称为群组切换或者组切换。
进行群组切换的群组可以包括一个或者多个IAB节点，便于说明，本申请实施例将群组切换中父节点发生变化的节点称为迁移(migrating)IAB节点或者迁移节点，迁移IAB节点在群组切换前的父节点为源父节点，迁移IAB节点在群组切换后的父节点为目标父节点，例如，图6中，IAB node 1可以称为迁移IAB节点，IAB node 2可以称为IAB node 1的源父节点，IAB node 3可以称为IAB node 1的目标父节点。
IAB donor 1可以称为群组切换的源IAB donor，或者群组中的一个或者多个节点的源IAB donor，或者群组中一个或者多个节点在群组切换过程中的源IAB donor。类似地，IAB donor 2可以称为群组切换的目标IAB donor，或者群组中的一个或者多个节点的目标IAB donor，或者群组中一个或者多个节点在群组切换过程中的目标IAB donor。
群组切换过程可以理解为群组切换的过程，可以包括从源IAB donor判决切换，至群组中的一个或者多个节点执行切换的过程，群组中的一个或者多个节点可能切换成功或者切换失败，本申请实施例对此不作限制。
本申请中，源IAB donor可以称为源宿主节点或者源接入网设备，目标IAB donor可以称为目标宿主节点或者目标接入网设备，本申请实施例对此不作限制。
在群组切换中，由于每个节点连接的接入网设备发生了变化，群组中的每个节点均需要执行切换流程，并在切换后的新的小区中重新发起随机接入，群组中的每个节点都重新发起随机接入会对有限的随机接入的资源造成冲击，并且随机接入过程的大量信令会造成信令风暴。为了解决这一问题，考虑到群组中除了迁移IAB节点之外，迁移IAB节点的后代节点均为跟随迁移IAB节点进行的切换，每个后代节点的父节点可以不发生改变，每个后代节点接入的父节点服务的小区也可以不发生改变(小区本身的标识可以发生变化，也可以不改变，例如小区的NCGI或ECGI可能发生变化，小区的物理小区标识PCI可以不发生变化)，因此可以考虑使得群组中迁移IAB节点的后代节点在切换过程中无需执行随机接入(即执行免随机接入的切换)，但是免随机接入的切换可能会导致节点不确定何时切换成功，故而不能及时停止用于检测切换是否成功的定时器，而定时器超时将导致切换失败，该节点可能会发起RRC重建等过程，带来不必要的时延。为了解决这一问题，本申请提供了一种方案，使得群组中执行免随机接入切换的节点可以接收指示信息并可以根据该指示信息及时停止定时器，提高切换的成功率，降低切换的时延，保障切换后的通信性能。
图7是本申请实施提供的一种通信方法，可以应用在例如IAB系统的中继系统中。
可选的，在图7的中继系统中，可以发生群组切换，即某一群组从源接入网设备切换至目标接入网设备。进行群组切换的群组至少包括子节点和父节点，可以理解，在群组切换过程中，该子节点的父节点没有发生变化。可选的，该群组还可以包括一个或者多个其他IAB节点，例如，群组中的迁移IAB节点可以是父节点，该群组还可以包括父节点的除了子节点以外的其他后代节点，或者群组中的迁移IAB节点可以是父节点与源接入网设备之间的节点，该群组还可以包括该节点除了父节点和子节点以外的其他后代节点。
可选的，该子节点可以为IAB节点或者终端，父节点可以为IAB节点，父节点的上级节点可以为IAB节点，该源接入网设备可以为源IAB donor，该目标接入网设备可以为目标IAB donor。
以图6为例，进行群组切换的群组包括IAB node 1、终端1、IAB node 4和终端2。子节点为终端1或者IAB node 4，父节点为IAB node 1；或者，子节点为终端2，父节点为IAB node 4，源接入网设备为IAB donor 1，目标接入网设备为IAB donor 2。
如图7所示，该方法包括：
S701：接入网设备向父节点发送第一消息。
所述接入网设备可以是父节点和所述父节点的子节点在群组切换过程中的目标接入网设备。
可选的，该父节点可以称为第一节点，该子节点可以称为第二节点，可选的，该第二节点与该接入网设备之间可以存在一个或者多个其他节点。为了便于描述，下面以子节点和父节点进行描述。
在一种可能的实现方式中，S701可以包括所述目标接入网设备向源接入网设备发送第一消息，所述源接入网设备向所述父节点发送所述第一消息。
可以理解，所述源接入网设备可以是父节点和所述父节点的子节点在群组切换过程中的源接入网设备。
可以理解，所述源接入网设备与所述父节点之间可能具有其他一个或者多个节点，所述源接入网设备可以通过该其他一个或者多个节点向父节点发送所述第一消息。
可选的，所述目标接入网设备向所述源接入网设备发送的所述第一消息可以包括在切换请求响应消息中，所述源接入网设备向所述父节点发送的第一消息可以包括在F1AP消息(例如UE上下文修改请求消息)中。
S702：所述父节点向所述子节点发送第一消息。
可选的，S701至S702可以表述为，所述接入网设备通过所述父节点向所述子节点发送所述第一消息，或者所述子节点通过所述父节点接收来自所述接入网设备的所述第一消息。
可选的，所述子节点接收到所述第一消息后，可以进行免随机接入的切换。本申请实施例中，切换也可以称为RRC重配置，主小区组(master cell group，MCG)改变(change)或者辅小区组(secondary cell group，SCG)change。
可选的，所述子节点接收到所述第一消息前可以称为切换前。
可选的，所述第一消息可以是第一RRC重配置消息。本申请中的RRC重配置消息可以称为切换命令消息。
可选的，所述第一消息可以不包括随机接入的配置信息。
可选的，所述第一消息可以指示子节点免随机接入，所述指示可以是明示或者暗示。
例如，所述指示可以是明示，所述第一消息可以包括免随机接入的指示，子节点根据所述指示免随机接入。
又例如，所述指示可以是暗示，所述第一消息可以不包括所述免随机接入的指示，所述子节点和所述目标接入网设备可以约定，当所述子节点接收到第一消息时，免随机接入；或者，所述子节点和所述目标接入网设备可以约定，当所述第一消息不包括随机接入的配置信息时，所述子节点免随机接入；或者，实现中有其他方式进行指示，本申请实施例对此不作限定。
可选的，所述第一消息可以包括同步重配置(reconfigurationwithsync)信元。
可选的，上述免随机接入的指示可以携带在所述同步重配置信元中。
可选的，所述同步重配置信元不包括所述随机接入的配置信息。
可选的，所述子节点可以根据所述同步重配置信元可以确定所述子节点需要进行 切换，并且在所述切换中免随机接入。
由于子节点是跟随着父节点进行群组切换的，子节点和父节点不需要重新进行同步，IAB网络中，父节点可能具有一个或者多个子节点，通过子节点无需在父节点的小区中随机接入，可以大大减少子节点发起随机接入的次数，一方面可以减少切换带来的时延，另一方面可以避免大量子节点发起随机接入时随机接入资源受限的情况。
可选的，子节点在切换前和切换后的小区无线网络临时标识(cell radio network temporary identifier，C-RNTI)可以保持不变。
可选的，C-RNTI用于在父节点的小区中唯一地标识子节点，或者可以理解为子节点在接入的父节点的小区中的标识，本申请实施例对C-RNTI的名称不作限定，本申请中的C-RNTI可以替换成用于在小区中标识子节点的其他标识。
作为一种实施方式，第一消息可以不包括子节点的C-RNTI。
在该方式中，第一消息不包括子节点的C-RNTI，子节点接收到第一消息后，可以默认继续使用接收到第一消息之前的C-RNTI。
作为另一种实施方式，第一消息可以包括指示该子节点的C-RNTI不变的指示信息。
在该方式中，子节点可以根据该指示信息确定子节点的C-RNTI不变，从而在接收到第一消息后，继续使用接收到第一消息之前的C-RNTI。
作为再一种实施方式，第一消息可以包括子节点在接收第一消息之前的C-RNTI。
在该方式中，子节点可以根据第一消息中携带的C-RNTI，使用该C-RNTI。
虽然子节点在切换前后，子节点的父节点没有发生变化，但是为子节点服务的接入网设备发生了变化，例如，为子节点服务的接入网设备由源接入网设备变为目标接入网设备，而子节点接入的小区的标识(例如NCGI)中有一部分是接入网设备的标识，所以子节点在切换前后，虽然接入的小区没有改变，但接入的小区的标识发生了变化，也就是说，子节点接入的小区的部分配置发生了变化。通过上述几种实施方式，可以使得子节点的C-RNTI保持不变，从而减少子节点配置C-RNTI的过程，避免IAB的群组切换中的大量重新配置C-RNTI的工作，并且降低子节点的功耗，节约子节点的电量。
可选的，子节点在切换前和切换后的C-RNTI可以变化。例如，第一消息可以包括更新的C-RNTI，子节点在切换过程和完成切换后可以使用第一消息中的更新的C-RNTI。本申请对此不作限定。
S703：子节点启动定时器。
子节点接收到第一消息后，可以启动定时器。
可选的，该定时器可以用于监测子节点的切换是否成功。可选的，该定时器的时长可以包括在上述第一消息中。
S704：子节点向父节点发送第二消息。
可选的，子节点接收到第一消息后，可以进行免随机接入的切换，当切换完成后，子节点向父节点发送第二消息。
S705：父节点向目标接入网设备发送第二消息。
可选的，S705和S706可以表述为，子节点通过父节点向目标接入网设备发送第二消息；或者，目标接入网设备通过父节点接收来自子节点的第二消息。
可选的，该第二消息可以是第一RRC重配置完成消息，该第一RRC重配置完成消息可以称为切换完成消息。
S706：目标接入网设备向父节点发送第一指示信息。
可选的，目标接入网设备解析第二消息后，可以确定子节点重配置完成了，目标接入网设备可以向父节点发送第一指示信息，用以触发父节点向子节点发送第二指示信息。
可选的，该第一指示信息可以指示父节点向子节点发送第二指示信息，或者可以指示子节点重配置完成，或者可以指示子节点可以停止定时器，或者第一指示信息可以指示其他内容，只要能触发父节点向子节点发送第二指示信息的指示信息均可以是本申请中的第一指示信息。
可选的，该第一指示信息可以包括子节点的标识。可以理解，父节点可能具有多个子节点，通过第一指示信息携带子节点的标识，父节点接收到第一指示信息，可以确定向哪个子节点发送第二指示信息。
S706是可选的。
S707：父节点向子节点发送第二指示信息。
作为一种实施方式，存在S706，响应于第一指示信息，父节点向子节点发送第二指示信息。
作为另一种实施方式，不存在S706，父节点从子节点收到第二消息后，或者父节点向目标接入网设备发送第二消息后，可以确定子节点重配置完成了，父节点可以向子节点发送第二指示信息。
在上述两种实施方式中，该第二指示信息可以指示停止定时器。本申请实施例中，定时器可以是T304定时器(timer)或者定时器可以有其他名称，本申请对此不作限定。
例如，该第二指示信息可以通过明示的方式进行指示，该第二指示信息占用1比特(bit)或者多bit，该1bit或者多bit的信息指示停止定时器。
又例如，该第二指示信息可以通过暗示的方式进行指示。该第二指示信息可以为第一类型的MAC CE，第一类型可以理解为某种特定类型的MAC CE，子节点接收该类型的MAC CE时，可以停止定时器。该第一类型的MAC CE可以不携带信息或者携带信息，本申请实施例对此不作限定。可选的，该MAC CE的类型可以通过协议约定的MAC CE对应的逻辑信道标识(Logical channel ID,LCID)来标识。本申请对该MAC CE的类型不作限定。
又例如，该第二指示信息可以通过暗示的方式进行指示。该第二指示信息可以是携带UE竞争解决标识(UE Contention Resolution Identity)的MAC CE。可选的，该MAC CE可以是特定类型的MAC CE。可选的，该MAC CE的类型可以通过协议约定的MAC CE对应的逻辑信道标识(logical channel identifier,LCID)来标识。
可选的，携带UE竞争解决标识的MAC CE可以在PDSCH中传输，且该PDSCH是通过PDCCH调度的，该PDCCH是通过子节点的C-RNTI加扰的。从而，子节点 成功解析携带UE竞争解决标识的MAC CE后，可以认为接收到了第二指示信息，从而停止定时器。
可选的，携带UE竞争解决标识的MAC CE可以为任意一种类型的MAC CE，本申请实施例对此不作限制。
可选的，该UE竞争解决标识可以为任意一个数值，例如，该数值可以是子节点的C-RNTI，或者可以是C-RNTI中的一个或者多个bit的数值，或者，该数值可能是任意一个数值，该数值可以不具备含义，本申请对此不作限制。
S709：子节点停止定时器。
子节点接收到第二指示信息后，根据第二指示信息停止定时器。
图7的方法中，通过父节点向子节点发送第二指示信息，子节点可以及时停止定时器，避免因定时器超时导致的切换失败和后续的失败处理(例如执行RRC重建等恢复操作)，减小时延，提高业务传输的连续性。
可选的，图7的方法还可以包括：目标接入网设备向父节点发送第三消息。具体可以包括目标接入网设备向源接入网设备发送第三消息，以及源接入网设备向父节点发送第三消息。
可选的，第三消息可以是第三RRC重配置消息。
作为一种实施方式，父节点可以根据该第三消息，进行免随机接入的切换。该第三消息可以指示父节点免随机接入，具体可以是明示或者暗示，具体可以参考第一消息中的内容，在此不再描述。可选的，父节点的切换前和切换后的C-RNTI可以不变或者变化，具体可以参考S702中的内容，在此不再描述。
作为另一种实施方式，父节点可以根据该第三消息，进行执行随机接入的切换。该第三RRC重配置消息中可以包括随机接入的配置信息。
在上述两种实施方式中，父节点接收到第三消息后，可以启动定时器。该定时器用于监测父节点的切换是否成功。
可选的，父节点可以先接收到第一消息或者先向子节点发送第一消息，然后再收到第三消息。这样可以避免父节点收到第三消息后执行切换，停止从源宿主节点接收消息和/或数据，而无法为子节点转发第一消息的情况，具体可以通过如下实施方式实现。
作为一种实施方式，父节点在接收到第一消息，或者向子节点发送第一消息后，父节点向源接入网设备发送第三指示信息，用以触发源接入网设备向父节点发送第三消息。
可选的，该第三指示信息可以指示源接入网设备向父节点发送第三消息，或者可以指示父节点已经从源接入网设备接收到第一消息，或者已经向子节点发送第一消息，或者可以指示父节点已经做好接收第三消息的准备等等。需要说明的是，用以触发源接入网设备向父节点发送第三消息的信息均可以认为是本申请的第三指示信息，第三指示信息还可以指示其他内容，本申请实施例对此不作限定。
本申请以一个子节点进行了说明，可以理解，父节点可以具有一个或者多个子节点，每个子节点都会通过该父节点接收到该子节点的第一消息。
可选的，父节点可以从源接入网设备接收到所有子节点的第一消息，或者向每个 子节点都发送该子节点的第一消息后，该父节点向源接入网设备发送第三指示信息。
可选的，该第三指示信息可以携带在F1AP消息中，该F1AP消息可以是非UE相关(non-UE associated)的F1AP消息。
或者，可选的，该父节点在接收到所有子节点的第一消息或向每个子节点发送该子节点的第一消息后，父节点可以向源接入网设备发送F1AP消息，例如针对该子节点的UE上下文修改响应消息，该第三指示信息可以携带在父节点为最后一个子节点发送的UE上下文修改响应消息中。
作为另一种实施方式，该父节点在接收到第一消息或向子节点发送第一消息后，父节点可以向源接入网设备发送F1AP消息，例如针对该子节点的UE上下文修改响应消息，源接入网设备可以在收到UE上下文修改响应消息后，再向父节点发送第三消息。
可以理解，若父节点具有多个子节点，该父节点在接收到每个子节点的第一消息或者向每个子节点发送该子节点的第一消息后，父节点可以向源接入网设备发送F1AP消息，例如针对该子节点的UE上下文修改响应消息，源接入网设备可以在收到父节点发送的针对所有子节点的UE上下文修改响应消息后，再向父节点发送第三消息。
可选的，图7的方法还可以包括：源接入网设备向目标接入网设备发送切换请求消息，切换请求消息包括以下一项或者多项：一个或者多个节点的小区无线网络临时标识，所述一个或者多个节点接入的小区的标识和一个或者多个后代节点在网络拓扑中的层级信息。该一个或者多个节点为群组中的一个或者多个节点，包括子节点和父节点。
可选的，一个或者多个节点在网络拓扑中的层级信息用于确定该一个或者多个节点的定时器的时长。
可选的，第一消息和/或第三消息可以携带在目标接入网设备向源接入网设备发送的切换请求响应消息中。
可选的，上述第一消息包括定时器的时长的信息，S703中子节点可以根据该定时器的时长的信息设置定时器，并启动定时器。
可选的，上述第三消息包括定时器的时长的信息，父节点接收到第三消息后，开一根据第一消息中的定时器的时长的信息设置定时器，并启动定时器。
图8是本申请实施例提供的一种群组切换的方法，可以应用在例如IAB系统的中继系统中。下面结合图8对图7进行进一步的说明。
图8中，某一群组进行群组切换，从源接入网设备切换至目标接入网设备，该群组至少包括第一节点、第二节点和第三节点。其中，第三节点是迁移IAB节点；第三节点是第二节点的父节点，第二节点是第一节点的父节点。第三节点在切换前与源父节点相连，第三节点在切换后与目标父节点相连，可选的，源父节点可以是源接入网设备，目标父节点可以是目标接入网设备。其中，迁移IAB节点是需要在切换过程更换父节点的IAB节点。
可选的，图8中的第一节点和第二节点可以分别是图7中的子节点和父节点，或者图8中的第二节点和第三节点可以分别是图7中的子节点和父节点。
需要说明的是，可选的，第三节点还可以具有其他一个或者多个子节点，本申请中第二节点的内容同样适用于第三节点的其他一个或者多个子节点。可选的，第二节点还可以具有其他一个或者多个子节点，本申请中第一节点的内容同样适用于第二节点的其他一个或者多个子节点。
以图6为例，第一节点是终端2，第二节点是IAB node 4，第三节点是IAB node 1，源接入网设备为IAB donor 1，目标接入网设备为IAB donor 2，源父节点是IAB node 2，目标父节点是IAB node 3。图6中IAB node 1还有一个子节点终端1，IAB node 4的内容同样适用于终端1。若IAB node 4还有一个子节点IAB node 5(图中没有示意)，终端2的内容同样适用于IAB node 5。
如图8所示，该方法包括：
S801：第三节点向源父节点发送测量报告。
S802：源父节点向源接入网设备发送测量报告。
S803：源接入网设备向目标接入网设备发送切换请求消息。
可选的，源接入网设备根据测量报告判决第三节点从源接入网设备切换至目标接入网设备，并向目标接入网设备发送切换请求消息。
可选的，该群组切换请求消息包括以下一项或者多项：群组中每个节点(例如可以是IAB节点或者终端)接入的小区的小区标识，该节点在接入的小区中的C-RNTI，和该节点在网络拓扑中的层级信息。
可选的，每个节点接入的小区的小区标识，可以是节点接入的主小区的小区标识，主小区可以称为特殊小区(special Cell，SpCell)。
可选的，在上述多种实施方式中，该小区标识可以包括物理小区标识(physical cell identifier，PCI)，NR小区标识(NR Cell Identity，NCI)，NR小区全球标识(NR cell global identifier，NCGI)，E-UTRAN小区全球标识(E-UTRAN cell global identifier，ECGI)中的一种或者多种。
可选的，迁移IAB节点(即第三节点)的接入的小区的小区标识可以是第三节点的目标小区的小区标识。可以理解，源接入网设备判决切换后，可以决定将第三节点的目标小区的小区标识携带在切换请求消息中发送给目标接入网设备。可选的，目标小区的小区标识可以是NGCI或者ECGI。
可选的，迁移IAB节点的后代节点在群组切换的过程中，其父节点没有发生变化。该后代节点接入的小区的小区标识可以是该后代节点在切换前接入的小区的小区标识。
可选的，一个节点接入的小区的小区标识和该节点在接入的小区中的C-RNTI可以唯一地标识该节点。
可选的，层级信息用于表示某个节点在网络拓扑中所处的相对位置或者与其他节点的连接关系。
示例性地，该层级信息可以是相对于迁移中继节点(即第三节点)的层级或者位置，例如，假设第三节点的层级为0(可以为其他数值，本申请实施例不作限定)，第三节点的一个或者多个子节点的层级为1，即第二节点的层级为1，第三节点的一个或者多个孙节点的层级为2，即第一节点的层级为2，以此类推，如某个后代节点 通过X跳链路连接第三节点，则该后代节点的层级信息可以记为X，X为正整数。或者，该层级信息可以是相对于其他节点的层级，该其他节点可以是第二节点、第一节点或者源父节点至源宿主节点的某个节点等，本申请实施例对此不作限定。
作为一种实施方式，该切换请求消息可以是组切换请求消息，该组切换请求消息可以称为群组切换请求消息，用于为群组请求切换。
表1是群组切换请求消息的一种示意图。如表1所示，组切换请求消息包括多个项目(item)，每个item对应于一个节点，每个节点的item中进一步包括一个或者多个item，该一个或者多个item包括每个节点的接入的小区的小区标识，C-RNTI和/或者层级信息。在表1中，每个节点的item都是并列的。
Figure PCTCN2020103893-appb-000001
表1
表2是群组切换请求消息的另一种示意图。如表2所示，组切换请求消息包括一个item，该item对应于第三节点，第三节点的item中进一步包括一个或者多个item，该一个或者多个item包括第三节点接入的小区的小区标识，C-RNTI和/或层级信息，以及第二节点；第二节点的item包括第二节点接入的小区的小区标识，C-RNTI和/或层级信息，以及第一节点；第二节点的item包括第二节点接入的小区的小区标识，C-RNTI和/或层级信息。在表2中，每个节点的item包括该节点的子节点的item。
Figure PCTCN2020103893-appb-000002
表2
可选的，如表2所示的每个节点的item包括该节点的子节点的item的情况下， 每个节点的item中可以不携带该节点的层级信息，通过各个节点的item的相互包含关系，可以得到各个节点的层级信息。例如可以根据上述表2中的信息的结构，推断出第一节点、第二节点、第三节点之间的相对拓扑关系(第二节点是第三节点的子节点，第一节点是第二节点的子节点)，进而还可以获知各个节点的层级信息(例如，若第三节点层级为0，第二节点层级为1，第一节点层级为2)。
上述表1和表2仅仅是示意，群组切换请求消息可以以其他形式存在，本申请实施例对此不作限定。
作为另一种实施方式，该切换请求消息可以包含一条或者多条独立的切换请求消息，其中一条切换请求消息对应于一个节点，或者可以理解为一条切换请求消息为一个节点请求切换。
可选的，在该实施方式下，每个节点的切换请求消息包括该节点接入的小区的小区标识，该节点在接入的小区中的C-RNTI，和/或该节点在网络拓扑中的层级信息。
S804：目标接入网设备向源接入网设备发送切换请求响应消息。
作为一种实施方式，若S803中的切换请求消息是组切换请求消息，S804的切换请求响应消息可以是组切换请求响应消息，该组切换请求响应消息可以称为群组切换请求响应消息。
可选的，该组切换请求响应消息包括每个节点的RRC重配置消息。
为了清楚，本申请将第一节点的RRC重配置消息称为第一RRC重配置消息，将第二节点的RRC重配置消息称为第二RRC重配置消息，将第三节点的RRC重配置消息称为第三RRC重配置消息。
在该实施方式中，组切换请求响应消息包括第一RRC重配置消息、第二RRC重配置消息和第三RRC重配置消息。
作为另一种实施方式，如S803中的切换请求消息包括一条或者多条独立的切换请求消息，S804的切换请求响应消息可以包括一条或者多条独立的切换请求响应消息，其中，每条切换请求响应消息对应于一个节点，每个节点的切换请求响应消息包括该节点的RRC重配置消息。
在该另一种实施方式中，S803的切换请求消息包括第一切换请求消息，第二切换请求消息和第三切换请求消息，S804的切换请求响应消息包括第一切换请求响应消息，第二切换请求响应消息和第三切换请求响应消息。其中，第一切换请求响应消息是第一节点的切换请求响应消息，包括第一RRC重配置消息；第二切换请求响应消息是第二节点的切换请求响应消息，包括第二RRC重配置消息；第三切换请求响应消息是第三节点的切换请求响应消息，包括第三RRC重配置消息。
可选的，在上述多种实施方式中，每个节点的RRC重配置消息可以包括该节点的定时器的时长信息。下面对节点的定时器的时长信息作进一步的说明。
可选的，目标接入网设备可以根据S803中切换请求响应消息的每个节点的层级信息确定该节点的定时器的时长。
可选的，层级越大的后代节点，可以理解为与迁移节点(即第三节点)之间的回传链路的跳数越多的节点，定时器的时长越长；层级越小的节点，可以理解为与第三节点之间的回传链路的跳数越少的节点，定时器的时长越短。
例如，第一节点的层级为2，第一节点的定时器的时长为200ms；第二节点的层级为1，第二节点的定时器的时长为150ms；第三节点的层级为0，第三节点的定时器的时长为100ms。
作为一种实施方式，该定时器的时长信息可以直接指示定时器的时长。
例如，第一节点的定时器的时长信息指示200ms，第二节点的定时器的时长信息指示150ms，第三节点的定时器的时长信息指示100ms。
作为另一种实施方式，该定时器的时长信息可以包括一个或者多个参数，该一个或者多个参数用于确定定时器的时长。每个节点收到该节点的定时器的时长信息后，可以根据该一个或者多个参数得到定时器的时长。
可选的，该一个或者多个参数可以通过某种运算得到定时器的时长，该运算可以包括相乘或者取幂等，本申请对运算的方式不作限定。
例如，该一个或者多个参数包括基础定时器的时长和缩放因子，每个节点可以通过基础定时器的时长和缩放因子进行运算，得到该节点的定时器的时长。
例如，第一节点的定时器的时长信息包括基础定时器的时长50ms，缩放因子4，第一节点可以通过50乘以4，得到第一节点的定时器的时长200ms；第二节点的定时器的时长信息包括基础定时器的时长50ms，缩放因子3，第一节点可以通过50乘以3，得到第一节点的定时器的时长150ms。第一节点的定时器的时长信息包括基础定时器的时长50ms，缩放因子2，第一节点可以通过50乘以2，得到第一节点的定时器的时长100ms。
通过源接入网设备向目标接入网设备发送层级信息，目标接入网设备可以根据节点所处的层级合理地确定定时器的时长，避免由于定时器的时长设置不合理带来的切换失败，可以减少切换的时延，并减少信令开销。
可选的，S803至S804的切换请求消息和切换请求响应消息可以与图7中的切换请求消息和切换请求响应消息相互参考。
S805：源接入网设备向第二节点发送下行F1AP消息，例如UE上下文修改请求(UE context modification request)消息，其中包括第一RRC重配置消息。可选的，所述下行F1AP消息(例如UE上下文修改请求消息)还可以包括指示第二节点停止与第一节点之间的数据传输的指示信息。
可选的，该指示信息可以携带在传输动作指示(transmission action indicator)信元中。第二节点可以读取该指示信息，然后停止与第一节点之间的数据传输，包括与第一节点的下行数据传输和/或上行数据传输。具体的，第二节点可以在执行了步骤S806之后，停止与第一节点之间的数据传输。
S806：第二节点向第一节点发送第一RRC重配置消息。
可选的，第一RRC重配置消息可以不包括随机接入的配置信息。可选的，第一RRC重配置消息可以指示子节点免随机接入，具体可以是明示或者暗示，可以参考S702中第一消息的内容。
可选的，第一节点在切换前和切换后的C-RNTI可以保持不变，具体地，第一RRC重配置消息可以不包括第一节点的C-RNTI，或者指示该第一节点的C-RNTI不变的指示信息，或者可以包括第一节点在接收第一消息之前的C-RNTI。或者，第一节点在 切换前和切换后的C-RNTI可以变化。具体可以参考S702中的内容。
S807：第一节点启动定时器。
第一节点接收到第一RRC重配置消息后可以启动定时器。具体可以参考S703的内容。
可选的，若第一RRC重配置消息包括定时器的时长的信息，第一节点可以根据该定时器的时长的信息得到定时器的时长，并对定时器进行设置，然后启动定时器。
S808：第二节点向源宿主节点发送上行F1AP消息，例如UE上下文修改响应(UE CONTEXT MODIFICATION RESPONSE)消息。
步骤S808为可选步骤，若步骤S805中的下行F1AP消息为UE上下文修改请求消息，则需要步骤S808。
S808中的UE上下文修改响应消息可以理解为第二节点针对第一节点反馈的UE上下文修改响应消息。
S809：第一节点向第二节点发送第一RRC重配置完成消息。
S810：源接入网设备向第三节点发送下行F1AP消息，例如UE上下文修改请求(UE context modification request)消息，其中包括第二RRC重配置消息。可选的，该下行F1AP消息(例如UE上下文修改请求消息)还可以包括指示第三节点停止与第二节点之间的数据传输的指示信息。第三节点可以读取该指示信息，然后停止与第二节点之间的数据传输，包括与第二节点的下行数据传输和/或上行数据传输。该指示信息的内容可以参考S805的内容。
可选的，S810可以发生在S805和/或S806之后。具体可以通过如下方式：
作为一种实施方式，S805或者S806后，第二节点可以向源接入网设备发送指示信息，用以触发源接入网设备向第二节点发送第二RRC重配置消息，即触发源接入网设备执行S810。该指示信息可以参考图7中的第三指示信息的内容。
可选的，若第二节点除了第一节点以外，还有其他子节点，第二节点可以从源接入网设备接收到所有子节点的RRC重配置消息或者向所有子节点发送RRC重配置消息后，向源接入网设备发送指示信息。
例如，以图6为例，第二节点为IAB node 4，第一节点可以为终端2，IAB node 4除了子节点终端2，还有可以有子节点IAB node 5(图6中没有示意)，则IAB node 4从IAB donor 1接收第一RRC重配置消息(终端2的RRC重配置消息)和IAB node 5的RRC重配置消息后，IAB node 4向IAB donor 1发送指示信息。或者，IAB node 4向终端2发送第一RRC重配置消息，且IAB node 4向IAB node 5发送IAB node 5的RRC重配置消息后，IAB node 4向IAB donor 1发送指示信息。
可选的，该指示信息可以携带在发送给源接入网设备的上行F1AP消息中。
可选的，该指示信息可以携带在第二节点发送的针对最后一个子节点的上行F1AP消息(例如UE上下文修改请求响应消息)中。
例如，IAB node 4先从IAB donor 1接收到终端2的UE上下文修改请求消息，其中包含终端2的RRC重配置消息，IAB node 4向终端2发送RRC重配置消息，IAB node 4为终端2向IAB donor 1发送UE上下文修改请求响应消息，然后，IAB node 4从IAB donor 1接收到IAB node 5的UE上下文修改请求消息，其中包含IAB node 5 的RRC重配置消息，IAB node 4向IAB node 5发送RRC重配置信息，IAB node 4为IAB node 5向IAB donor 1发送UE上下文修改请求响应消息。该指示信息可以携带在IAB node 4为IAB node 5向IAB donor 1发送的UE上下文修改请求响应消息中。
作为另一种实施方式，源接入网设备可以在S808后，再执行S810。
可选的，若第二节点除了第一节点以外，还有其他子节点，源接入网设备可以在从第二节点接收到针对所有子节点的UE上下文修改响应消息后，再执行S810。
例如，IAB donor 1在从IAB node 4接收IAB node 4发送的针对终端2的UE上下文修改请求响应消息和针对IAB node 5的UE上下文修改请求响应消息后，再执行S810。
通过上述两种实施方式，可以避免若S810发生在S805之前，第二节点收到第二RRC重配置消息后，会执行切换的动作，停止与源接入网设备之间的数据传输，导致第二节点无法接收且无法向第一节点转发该第一RRC重配置消息的情况，可以保证第二节点可以为第一节点转发第一RRC重配置消息，保障第一节点的切换的成功率。
S811：第三节点向第二节点发送第二RRC重配置消息。
可选的，第二RRC重配置消息可以不包括随机接入的配置信息。可选的，第二RRC重配置消息可以指示子节点免随机接入，具体可以是明示或者暗示，可以参考图7中第一消息的内容。
可选的，第二节点在切换前和切换后的C-RNTI可以保持不变，具体地，第二RRC重配置消息可以不包括第二节点的C-RNTI，或者指示该第二节点的C-RNTI不变的指示信息，或者可以包括第二节点在接收第一消息之前的C-RNTI。或者，第二节点在切换前和切换后的C-RNTI可以变化。具体可以参考S702中的内容。
S812：第二节点启动定时器。
第二节点接收到第二RRC重配置消息后可以启动定时器。具体可以参考S703的内容。
可选的，若第二RRC重配置消息包括定时器的时长的信息，第二节点可以根据该定时器的时长的信息得到定时器的时长，并对定时器进行设置，然后启动定时器。
S813：第三节点向源宿主节点发送上行F1AP消息，例如UE上下文修改响应消息。
步骤S813为可选步骤，若步骤S810中的下行F1AP消息为UE上下文修改请求消息，则需要步骤S813。S813中的UE上下文修改响应消息可以理解为第三节点针对第二节点反馈的UE上下文修改响应消息。
S814：第二节点向第三节点发送第二RRC重配置完成消息。
S815：源接入网设备向源父节点发送下行F1AP消息，例如UE上下文修改请求(UE context modification request)消息，包括第三RRC重配置消息。
可选的，该下行F1AP消息(例如UE上下文修改请求消息)中还可以包括指示源父节点停止与第三节点之间的数据传输的指示信息。源父节点可以读取该指示信息，然后停止与第三节点之间的数据传输，包括与第三节点的下行数据传输和/或上行数据传输。该指示信息的内容可以参考S805和S810中的内容。
可选的，与上述S810发生在S805和/或S806之后类似，S815可以发生S810和/或S811之后。具体可以通过如下方式实现：
作为一种实施方式，S810或者S811之后，第三节点可以向源接入网设备发送指示信息，用以触发源接入网设备向第三节点发送第三RRC重配置消息。该指示信息可以参考图7中的第三指示信息的内容。
可选的，若第三节点除了第二节点以外，还有其他子节点，第三节点可以从源接入网设备接收到所有子节点的RRC重配置消息或者向所有子节点发送RRC重配置消息后，向源接入网设备发送该指示信息。
例如，以图6为例，第三节点为IAB node 1，第二节点为IAB node 4，IAB node 1除了子节点IAB node 4，还有可以有子节点终端1，则IAB node 1从IAB donor 1接收第二RRC重配置消息(IAB node 4的RRC重配置消息)和终端1的RRC重配置消息后，IAB node 1可以向IAB donor 1发送该指示信息。或者，IAB node 1向IAB node4发送第二RRC重配置消息，且向IAB node 1向终端1发送终端1的RRC重配置消息后，IAB node 1向IAB donor 1发送该指示信息。
作为另一种实施方式，源接入网设备可以在S813后，再执行S815。
可选的，若第三节点除了第二节点以外，还有其他子节点，源接入网设备可以在从第三节点接收到针对所有子节点的UE上下文修改响应消息后，再执行S815。
例如，IAB donor 1在从IAB node 1接收IAB node 1发送的针对终端1的UE上下文修改请求响应消息和针对IAB node 4的UE上下文修改请求响应消息后，再执行S815。
S816：源父节点向第三节点发送第三RRC重配置消息。
作为一种实施方式，第三RRC重配置消息可以指示第三节点在目标小区执行随机接入，第三RRC重配置消息可以包含目标小区的小区标识(例如目标小区的PCI)。其中目标小区为第三节点的目标父节点所服务的小区。
可选的，第三RRC重配置消息可以包括随机接入的配置信息和/或新的C-RNTI。
作为另一种实施方式，第三RRC重配置消息可以指示第三节点免随机接入。
可选的，第三RRC重配置消息可以不包括随机接入的配置信息。可选的，第三RRC重配置消息可以指示子节点免随机接入，具体可以是明示或者暗示，可以参考图7中第一消息的内容。
第三节点的父节点虽然发生了变化，即由源父节点变为目标父节点，但是若源父节点和目标父节点是同步的，第三节点可以不需要再与目标父节点进行同步，通过第三节点免随机接入，可以避免随机接入带来的时延，减少切换的时延，另一方面可以避免随机接入资源受限的情况。
可选的，第三节点在切换前和切换后的C-RNTI可以保持不变，具体地，第三RRC重配置消息可以不包括第三节点的C-RNTI，或者指示该第三节点的C-RNTI不变的指示信息，或者可以包括第三节点在接收第三RRC重配置消息之前的C-RNTI。或者，第三节点在切换前和切换后的C-RNTI可以变化。具体可以参考S702中的内容。
S817：第三节点启动定时器。
第三节点接收到第三RRC重配置消息后可以启动定时器。具体可以参考S703的 内容。
可选的，若第三RRC重配置消息包括定时器的时长的信息，第三节点可以根据该定时器的时长的信息得到定时器的时长，并对定时器进行设置，然后启动定时器。
S818：源父节点向源宿主节点发送上行F1AP消息，例如UE上下文修改响应消息。
步骤S818为可选步骤，若步骤S815中的下行F1AP消息为UE上下文修改请求消息，则需要步骤S818。S818中的UE上下文修改响应消息可以理解为源父节点针对第三节点反馈的UE上下文修改响应消息。
可选的，第三节点接收到第三RRC重配置消息后，第三节点可以根据第三RRC重配置消息在目标小区进行随机接入或者免随机接入，下面结合方式1和方式2进行说明。需要说明的是，方式1和方式2是择一进行的。其中，方式1包括S819和S820，方式2包括S823至S825，无论是方式1，还是方式2，S821和S822都是存在的。
S819：第三节点可以根据第三RRC重配置消息进行随机接入。
在该实施方式中，第三节点的父节点发生了变化，第三节点可以通过随机接入过程与目标父节点重新进行同步，保证第三节点与目标父节点之间的通信的性能。
S820：第三节点停止定时器。
第三节点在S819中的随机接入成功后，第三节点可以停止定时器。
S821：第三节点向目标父节点发送第三RRC重配置完成消息。
S822：目标父节点向目标接入网设备发送第三RRC重配置完成消息。
可选的，S822中的第三RRC重配置完成消息可以携带在上行F1AP消息中，例如上行RRC消息传输(UL RRC message transfer)消息中。
S823：目标接入网设备向目标父节点发送第一指示信息。
方式2中，第三节点免随机接入，不存在S819和S820，在S821和S822后，目标接入网设备解析第三RRC重配置完成消息后，可以确定第三节点切换完成了，目标接入网设备可以向目标父节点发送第一指示信息，以触发S824。
S823是可选的。
S824：目标父节点向第三节点发送第二指示信息。
作为一种实施方式，存在S823，响应于第一指示信息，目标父节点向第三节点发送第二指示信息。
作为另一种实施方式，不存在S823，S821或者S822之后，目标父节点向第三节点发送第二指示信息。
S825：第三节点停止定时器。
第三节点接收到第二指示信息后，根据第二指示信息停止定时器。
S826：源接入网设备向目标接入网设备发送包含数据包传输状态的消息，例如序列号(sequence number，SN)状态传输(SN Status Transfer)消息。
其中包含源接入网设备的上行和/或下行数据包传输状态信息，该上行数据包和/或下行数据包可以是PDCP分组数据单元(packet data unit，PDU)。
目标接入网设备接收到SN Status Transfer消息后，可以根据其中的数据包传输状态，在第三节点完成切换后继续上行和/或下行数据的传输，避免终端业务数据的丢失。
可选的，若源接入网设备的CU为CP和UP分离的架构，源接入网设备的CU的CP可以发起承载上下文修改流程，用于获取上行/下行的数据包传输状态(例如对应于每个UE数据无线承载的PDCP PDU的SN状态信息)，并交互用于源接入网设备和目标接入网设备之间进行数据转发(data forwarding)的端点配置信息。例如，源接入网设备的CU的CP就可以向源接入网设备的CU的UP发送承载上下文修改请求消息，源接入网设备的CU的UP可以向源接入网设备的CU的CP发送承载上下文修改响应消息，该承载上下文修改响应消息包括上行/下行PDCP PDU的SN状态信息，还可以包含源接入网设备的CU的UP用于数据转发(data forwarding)的隧道端点信息。
可选的，若目标接入网设备为CU的CP和CU的UP分离的架构，源接入网设备向目标接入网设备的CU的CP发送数据和SN状态。目标接入网设备的CU的CP可以发起承载上下文修改流程，从而向目标接入网设备的CU的UP发送F1-U接口的下行传输网络层地址信息(DL TNL address information)，和/或，数据包的传输状态(例如对应于每个UE数据无线承载的PDCP PDU的SN状态信息)。例如，例如，目标接入网设备的CU的CP就可以向目标接入网设备的CU的UP发送承载上下文修改请求消息，上下文修改请求消息包括数据包的传输状态，目标接入网设备的CU的UP可以向目标接入网设备的CU的CP发送承载上下文修改响应消息。
可选的，图8的方法还可以包括：目标接入网设备向第三节点发送RRC重配置消息，RRC重配置消息可以包括第三节点的BAP层的配置信息，和/或第三节点与目标父节点之间的回传RLC信道的配置信息。
可选的，第三节点的BAP层的配置信息，和/或第三节点与目标父节点之间的回传RLC信道的配置信息可以包括在S815和S816中的第三RRC重配置消息中。
可选的，第三节点的BAP的配置信息可以包括目标接入网设备为第三节点分配的BAP层的标识，默认的(default)上行的BAP层的路由标识(BAP routing ID)。第三节点的BAP的配置信息还可以包含：一个或多个其他的非默认的上行的BAP层的路由标识，以及与每个上行BAP层的路由标识对应的第三节点的下一跳(即目标父节点)的BAP层标识。其中，每个上行的BAP层的路由标识(包括默认的上行的BAP层的路由标识)，包含一个BAP地址(BAP address)和BAP路径标识(BAP path ID)，该BAP address用于标识目标接入网设备，或者目标接入网设备的DU，该BAP path ID用于标识从第三节点到BAP address所标识的设备的一条传输路径。
可以理解的是，通过RRC重配置消息包含的第三节点的BAP层的配置信息，可用于传输步骤S827中的相应数据包，包括例如第三节点与目标接入网设备之间建立F1接口的F1AP消息，第三节点与目标接入网设备之间建立SCTP偶联过程相关的SCTP握手消息等。
可选的，第三节点与目标父节点之间回传RLC信道的配置信息可以包括第三节点和目标父节点之间的默认的回传RLC信道的配置信息等。
S827：第三节点与目标接入网设备建立F1接口。
可选的，第三节点在建立F1接口之前，与目标接入网设备之间建立SCTP偶联(Association)。
例如，第三节点可以向目标接入网设备发起F1接口的建立过程。又例如，第三节点可以向目标接入网设备发起F1接口的重建过程，从而触发目标接入网设备向源接入网设备请求源接入网设备处维护的源接入网设备与第三节点之间的F1接口的上下文，然后目标接入网设备对该F1接口的上下文进行更新。再例如，目标接入网设备先从源接入网设备获取源接入网设备处维护的源接入网设备与第三节点之间的F1接口的上下文，然后目标接入网设备可以发起F1接口的上下文更新过程，对源接入网设备与第三节点之间的F1接口的上下文进行更新。
可选的，S827后，该方法还可以包括：目标接入网设备向第三节点发送BAP层的更新配置，此步骤中的配置信息可以包含以下内容中的一项或多项：
第三节点作为接入IAB节点时的上行映射配置，用于发送上行数据包的BAP层路由标识，与该路由标识对应的下一跳节点的标识，以及第三节点与该下一跳节点之间用于承载此类上行数据包的BH RLC channel的标识，此处的上行数据包可以是以下中的任意一种：与UE相关的F1AP消息、非UE相关的F1AP消息、非F1接口消息、以及F1-U数据包；第三节点作为中间IAB节点时的承载映射关系，具体包含：第三节点的上一跳节点的标识，第三节点与上一跳节点之间链路上的BH RLC channel标识，第三节点的下一跳节点的标识，第三节点与下一跳节点之间链路上的BH RLC channel标识。
S828：第三节点向目标接入网设备发送上行F1AP消息，其中包含第二RRC重配置完成消息。
可选的，S828的第二RRC重配置完成消息可以携带在UL RRC message transfer消息中。
S829：目标接入网设备向第三节点发送第三指示信息。
S829中目标接入网设备接收到第二RRC重配置完成消息，并解析第二RRC重配置完成消息后，可以确定第二节点切换完成了，目标接入网设备可以向第三节点发送第三指示信息，以触发S830。
S829是可选的。
S830：第三节点向第二节点发送第四指示信息。
作为一种实施方式，存在S829，响应于第三指示信息，第三节点向第二节点发送第四指示信息。
作为另一种实施方式，不存在S829，S828之后，第三节点向第二节点发送第四指示信息。
S831：第二节点停止定时器。
第二节点接收到第四指示信息后，根据第四指示信息停止定时器。
S832：第二节点与目标接入网设备建立F1接口。
具体可以参考上文第三节点与目标接入网设备之间的F1接口的建立的过程，在此不再描述。
可选的，目标接入网设备还可以向第二节点发送BAP层配置信息和/或回传RLC信道的配置信息等，具体可以参考第三节点的内容，可以将S827中的第三节点替换为第二节点。
S833：第二节点向目标接入网设备发送上行F1AP消息，其中包含第一RRC重配置完成消息。
可选的，S830中的第一RRC重配置完成消息可以携带在UL RRC message transfer消息中。
S834：目标接入网设备向第二节点发送第五指示信息。
S833中目标接入网设备接收到第一RRC重配置完成消息，并解析第一RRC重配置完成消息后，可以确定第一节点切换完成了，目标接入网设备可以向第二节点发送第五指示信息，以触发S835。
S835：第二节点向第一节点发送第五指示信息。
作为一种实施方式，存在S8304，响应于第四指示信息，第二节点向第一节点发送第五指示信息。
作为另一种实施方式，不存在S834，S833之后，第二节点向第一节点发送第四指示信息。
S836：第一节点停止定时器。
第一节点接收到第五指示信息后，根据第五指示信息停止定时器。
S837：目标接入网设备与核心网完成路径切换。
可选的，核心网将传输第三节点和其后代节点的业务的用户面路径从源接入网设备转移至目标接入网设备。
S838：目标接入网设备向源接入网设备发送UE上下文释放(UE context release)消息。
可选的，如果源接入网设备的CU为CP-UP分离的架构，源接入网设备的CU的CP可以从目标接入网设备接收UE上下文释放消息，源接入网设备的CU的CP可以向源接入网设备的CU的UP发送承载上下文释放命令(bearer context release command)。
S839和S840描述了源接入网设备与源父节点之间的F1接口的UE上下文释放过程。
S839：源接入网设备向源父节点发送UE上下文释放命令(UE context release command)消息。
S840：源父节点向源接入网设备发送UE上下文释放完成(UE context release Complete)消息。
S841：释放源接入网设备与第三节点之间的路径上的BAP路由配置。
源接入网设备与第三节点之间的路径上的节点包括源接入网设备，以及源接入网设备与第三节点之间的其他节点，例如，源父节点。此步骤中的源接入网设备，具体可以是源接入网设备中的DU部分。
可选的，S841具体可以包括：源接入网设备向该路径上的节点分别发送用于释放第三节点或第一节点或第二节点相关的BAP层配置的F1AP消息，该路径上的节点收到F1AP消息后，释放该节点的相应BAP层配置。
可选的，图7和图8中，由接入网设备(例如源接入网设备或者目标接入网设备)执行的动作，可以由接入网设备的CU或者CU的CP执行。
可选的，图8中的第一节点可以是图7中的子节点，第二节点可以是图7中的父节点。S804至S807的内容可以与S701至S703的内容相互参考，S809可以与S704相互参考，S833可以与S705相互参考，S834至S836可以与S706至S708相互参考。S810至S811中的第二RRC重配置消息的内容可以与图7中的第三消息的内容相互参考。
可选的，图8中的第二节点可以是图7中的子节点，图8中的第三节点可以是图7中的父节点。S804，S810至S812的内容可以与S701至S703的内容相互参考，S814可以与S704相互参考，S828可以与S705相互参考，S829至S831可以与S706至S708相互参考。S815至S816的第三RRC重配置消息的内容可以与图7中的第三消息的内容相互参考。
可选的，图8中，第一节点、第二节点和第三节点的方法均可以单独实施，例如第三节点的方法可以单独实施。
可选的，图8中，第一节点、第二节点和第三节点的方法可以以组合的方式实施，例如该组合可以包括第一节点和第二节点，第二节点和第三节点，第一节点和第三节点，或者第一节点、第二节点和第三节点。
可选的，图8中的步骤一个或者多个步骤可以有不同的组合方式，下面结合多种设计进行说明：
在一种可能的设计中，图8的方法可以只包括S804、S805和S806，即第一节点通过第二节点从目标接入网设备接收第一RRC重配置信息，第一RRC重配置消息指示免随机接入。可选的，第一节点在切换前和切换后的C-RNTI可以保持不变。具体可以参考S804、S805和S806的内容。可选的，还可以包括图8中的其他一个或者多个步骤。
通过第一RRC重配置消息指示免随机接入，可以减少节点的切换时间，降低切换时延，节省信令开销，避免大量节点发起随机接入由于资源受限导致的频繁冲突或节点等待随机接入资源的时间过长。另外，通过C-RNTI保持不变，可以避免大量的重新配置的工作，并且节约第一节点的功耗。
在另一种可能的设计中，图8的方法可以只包括S805、S806、S810和S811，S810可以发生在S805和/或S806之后，具体可以参考图8中的内容。可选的，第一RRC重配置消息和/或第二RRC重配置消息可以指示随机接入或者免随机接入，本申请实施例对此不作限定。可选的，还可以包括图8中的其他一个或者多个步骤。
通过S810可以发生在S805和/或S806之后，可以确保子节点接收到RRC重配置消息后，才给父节点发送RRC重配置消息，避免因为父节点提前切换无法为子节点提供服务。
在又一种可能的设计中，图8的方法可以只包括S803，即源接入网设备向目标接入网设备发送切换请求消息，包括一个或者多个节点的C-RNTI，接入的小区的小区标识和/或在网络拓扑中的层级信息。可选的，目标接入网设备根据层级信息确定定时器的时长信息，并携带在RRC重配置消息中发送给该一个或者多个节点，具体可以 参考图8的内容。可选的，还可以包括图8中的其他一个或者多个步骤。
由图8可以看出，在群组切换中，在开始切换的阶段，先向群组中的最远端的节点(例如图8的第一节点)发送RRC重配置消息，然后再逐级发送上一级节点的RRC重配置消息，最后向迁移IAB节点发送RRC重配置消息；而在切换完成的阶段，首先向目标接入网设备迁移IAB节点的RRC重配置完成消息，然后逐级发送下一级的RRC重配置完成消息，最后发送最远端的节点的RRC重配置完成消息。因此，可以理解，在群组切换中，与迁移IAB节点之间的无线回传链路的跳数越大的节点，从开始切换到切换完成的过程占用的时间越长。
若定时器的时长设置的不合理，群组切换中的节点可能因定时器超时导致切换失败，节点判断自己切换失败后会发起RRC重建，而发起RRC重建过程会带来时延，并且会造成不必要的信令开销。另外，子节点发起RRC重建后，若父节点切换还没有完成，父节点不能为子节点提供服务，可能还会导致子节点的RRC重建失败，子节点进入空闲态，然后重新入网，而重新入网所需的时延很大，严重影响了用户体验。
通过源接入网设备向目标接入网设备发送层级信息，目标接入网设备可以根据节点所处的层级合理地确定定时器的时长，例如与迁移IAB节点之间的无线回传链路的跳数越大的节点，定时器的时长越大，与迁移IAB节点之间的无线回传链路的跳数越小的节点，定时器的时长越小。避免上述由于定时器的时长设置不合理带来的后果，可以减少切换的时延，并减少信令开销。
可选的，如图8所示，群组切换中，每个节点可以接收到自己的重配置消息，考虑到每个节点的重配置消息中一些信息可以是相同的，本申请提供了一种方案，在该方案中，目标接入网设备可以将这些相同的信息通过广播的方式发送。
例如，目标接入网设备广播群组重配置消息，该群组重配置消息包括主服务小区的公共配置，免随机接入的指示和/或定时器的时长信息等。
可选的，该群组重配置消息可以称为群组切换命令。
可选的，该定时器的时长信息可以指示S804中的基础定时器的时长，然后目标接入网设备可以分别向群组中的每个节点发送消息，该消息包括缩放因子，群组中的节点根据基础定时器的时长和缩放因子得到定时器的时长。
可选的，目标接入网设备还可以分别向群组中的每个节点单独发送消息，该消息包括每个节点之间不同的信息，例如，每个节点的PDCP层的配置(比如安全相关的配置)等。
通过将每个节点相同的信息通过广播的方式发送，可以节省空口的信令开销。尤其在IAB系统中，通过上述广播的方式，可以避免向群组中的多个节点单独发送信令带来的开销。
图7和图8以中继系统为例进行了介绍，需要说明的是，本申请实施例的方法同样适用于终端直接接入接入网设备的场景的单空口场景，例如图1的终端130直接接入接入网设备150通信的场景。
图9是本申请实施例提供的另一种通信方法，可以应用于终端直接接入接入网设 备的场景。下面结合图9进行说明。接入网设备150可以采用图2所示的CU-DU分离的架构。
可选的，终端130可以从接入网设备150切换至另一个接入网设备(图1中没有示意)，下文将接入网设备150称为源接入网设备，将该另一个接入网设备称为目标接入网设备，目标接入网设备可以采用图2所示的CU-DU分离的架构，其中，目标接入网设备的CU可以称为目标CU，目标接入网设备的DU可以称为目标DU。
S901：目标CU向源接入网设备发送第一消息。
可选的，源接入网设备可以采用CU-DU分离的架构，其中，源接入网设备的CU可以称为源CU，源接入网设备的DU可以称为源DU。S901可以包括：目标CU向源CU发送第一消息。
S902：源接入网设备向终端发送第一消息。
可选的，若源接入网设备可以采用CU-DU分离的架构，S902可以包括：源CU向源DU发送第一消息，源DU向终端发送第一消息。
S903：终端启动定时器。
S904：终端向目标DU发送第二消息。
S905：目标DU向目标CU发送第二消息。
S901至S905中的第一消息和第二消息可以参考图7中的第一消息和第二消息的内容。
S906：目标CU向目标DU发送第一指示信息。
S907：目标DU向终端发送第二指示信息。
S906至S907中的第一指示信息和第二指示信息可以参考图7中的第一指示信息和第二指示信息的内容。
S908：终端停止定时器。
图9中的目标DU可以执行图7中的父节点的动作，图9中的目标CU可以执行图7中接入网设备的动作，图9的终端可以执行图7中的子节点的动作。图9的其他内容可以参考图7，在此不再赘述。
下面结合图10至图13介绍本申请实施例提供的装置，图10至图13中的装置可以完成图7至图9中的方法，装置的内容可以与方法的内容相互参考。
图10是本申请实施例提供的一种终端的结构示意图，该终端可以实现上述方法实施例中终端的功能。为了便于说明，图10示意了终端的主要部件，如图10所示：
终端包括至少一个处理器611、至少一个收发器612和至少一个存储器613。处理器611、存储器613和收发器612相连。可选的，终端还可以包括输出设备614、输入设备615和一个或多个天线616。天线616与收发器612相连，输出设备614、输入设备615与处理器611相连。
处理器611主要用于对通信协议以及通信数据进行处理，以及对整个终端进行控制，执行软件程序，处理软件程序的数据。
作为一种可选的实现方式，所述终端设备可以包括基带处理器和中央处理器。基带处理器主要用于对通信协议以及通信数据进行处理。中央处理器主要用于对整个终 端设备进行控制，执行软件程序，处理软件程序的数据。
图10中的处理器可以集成基带处理器和中央处理器的功能，本领域技术人员可以理解，基带处理器和中央处理器也可以是各自独立的处理器，通过总线等技术互联。本领域技术人员可以理解，终端设备可以包括多个基带处理器以适应不同的网络制式，终端设备可以包括多个中央处理器以增强其处理能力，终端设备的各个部件可以通过各种总线连接。所述基带处理器也可以表述为基带处理电路或者基带处理芯片。所述中央处理器也可以表述为中央处理电路或者中央处理芯片。对通信协议以及通信数据进行处理的功能可以内置在处理器中，也可以以软件程序的形式存储在存储器中，由处理器执行软件程序以实现基带处理功能。
存储器613主要用于存储软件程序和数据。存储器613可以是独立存在，与处理器611相连。可选的，存储器613可以和处理器611集成在一起，例如集成在一个芯片之内，即片内存储器，或者存储器613为独立的存储元件，本申请实施例对此不做限定。其中，存储器613能够存储执行本申请实施例的技术方案的程序代码，并由处理器611来控制执行，被执行的各类计算机程序代码也可被视为是处理器611的驱动程序。
收发器612可以用于基带信号与射频信号的转换以及对射频信号的处理，收发器612可以与天线616相连。收发器612包括发射机(transmitter，Tx)和接收机(receiver，Rx)。具体地，一个或多个天线616可以接收射频信号，该收发器612的接收机Rx用于从天线接收所述射频信号，并将射频信号转换为数字基带信号或数字中频信号，并将该数字基带信号或数字中频信号提供给所述处理器611，以便处理器611对该数字基带信号或数字中频信号做进一步的处理，例如解调处理和译码处理。此外，收发器612中的发射机Tx用于从处理器611接收经过调制的数字基带信号或数字中频信号，并将该经过调制的数字基带信号或数字中频信号转换为射频信号，并通过一个或多个天线616发送所述射频信号。具体地，接收机Rx可以选择性地对射频信号进行一级或多级下混频处理和模数转换处理以得到数字基带信号或数字中频信号，所述下混频处理和模数转换处理的先后顺序是可调整的。发射机Tx可以选择性地对经过调制的数字基带信号或数字中频信号时进行一级或多级上混频处理和数模转换处理以得到射频信号，所述上混频处理和数模转换处理的先后顺序是可调整的。数字基带信号和数字中频信号可以统称为数字信号。可选的，发射机Tx和接收机Rx可以是由不同的物理结构/电路实现，或者可以由同一物理结构/电路实现，也就是说发射机Tx和接收机Rx可以继承在一起。
收发器也可以称为收发单元、收发机、收发装置等。可选的，可以将收发单元中用于实现接收功能的器件视为接收单元，将收发单元中用于实现发送功能的器件视为发送单元，即收发单元包括接收单元和发送单元，接收单元也可以称为接收机、输入口、接收电路等，发送单元可以称为发射机、发射器或者发射电路等。或者，可以将Tx、Rx和天线的组合成为收发器。
输出设备614以多种方式来显示信息。例如，输出设备614可以是液晶显示器(Liquid Crystal Display，LCD)、发光二级管(Light Emitting Diode，LED)显示设备、阴极射线管(Cathode Ray Tube，CRT)显示设备、或投影仪(projector)等。输入设 备615可以以多种方式接受用户的输入。例如，输入设备615可以是鼠标、键盘、触摸屏设备或传感设备等。
图11是本申请实施例提供的一种接入网设备的结构示意图，示例性地可以为接入网设备的结构示意图，该接入网设备可以采用CU-DU分离的架构。如图11所示，该基站可应用于如图1或图2或图3所示的系统中，实现上述方法实施例中接入网设备(源接入网设备和/或目标接入网设备)的功能。
接入网设备可包括一个或多个DU 1101和一个或多个CU 1102。所述DU 1101可以包括至少一个天线11011，至少一个射频单元11012，至少一个处理器11013和至少一个存储器11014。所述DU 1101部分主要用于射频信号的收发以及射频信号与基带信号的转换，以及部分基带处理。CU1102可以包括至少一个处理器11022和至少一个存储器11021。CU 1102和DU 1101之间可以通过接口进行通信，其中，控制面(control plane)接口可以为F1-C，用户面(user Plane)接口可以为F1-U。
所述CU 1102部分主要用于进行基带处理，对基站进行控制等。所述DU 1101与CU 1102可以是物理上设置在一起，也可以物理上分离设置的，即分布式基站。所述CU 1102为基站的控制中心，也可以称为处理单元，主要用于完成基带处理功能。例如所述CU 1102可以用于控制基站执行上述方法实施例中关于网络设备的操作流程。
具体的，CU和DU上的基带处理可以根据无线网络的协议层划分，具体可以参考上文的内容。
在一个实例中，所述CU 1102可以由一个或多个单板构成，多个单板可以共同支持单一接入指示的无线接入网(如5G网)，也可以分别支持不同接入制式的无线接入网(如LTE网，5G网或其他接入网)。所述存储器11021和处理器11022可以服务于一个或多个单板。也就是说，可以每个单板上单独设置存储器和处理器。也可以是多个单板共用相同的存储器和处理器。此外每个单板上还可以设置有必要的电路。所述DU 1101可以由一个或多个单板构成，多个单板可以共同支持单一接入指示的无线接入网(如5G网)，也可以分别支持不同接入制式的无线接入网(如LTE网，5G网或其他接入网)。所述存储器11014和处理器11013可以服务于一个或多个单板。也就是说，可以每个单板上单独设置存储器和处理器。也可以是多个单板共用相同的存储器和处理器。此外每个单板上还可以设置有必要的电路。
可选的，CU 1102可以通过DU 1101与接入网设备的子节点进行传输，CU 1102可以通过接口与其他接入网设备相连，CU 1102可以通过该接口从其他接入网设备(例如其他接入网设备的CU)接收数据和/或消息，或者CU 1102可以通过该接口向该其他接入网设备发送数据和/或消息。
图12是本申请实施例提供的一种通信装置的结构示意图，该通信装置可以是中继节点，可以实现上述方法实施例中的中继节点(例如IAB节点)的功能；或者该通信装置可以是接入网设备，可以实现上述方法实施例中的源接入网设备或者目标接入网设备的功能。为了便于说明，图12示意了通信装置的主要部件，如图12所示：
通信装置包括至少一个处理器711、至少一个存储器712、至少一个收发器713、至少一个网络接口714和一个或多个天线715。处理器711、存储器712、收发器713 和网络接口714相连，例如通过总线相连，在本申请实施例中，所述连接可包括各类接口、传输线或总线等，本实施例对此不做限定。天线715与收发器713相连。网络接口714用于使得通信装置通过通信链路，与其它网络设备相连。
收发器713、存储器712以及天线716可以参考图10中的相关描述，实现类似功能。
图13为本申请实施例提供的一种通信装置的结构示意图。通信装置可以执行上述方法实施例中描述的方法，可以参考上述方法实施例的说明。通信装置可以用于通信设备、电路、硬件组件或者芯片中，例如通信装置可以是终端、终端中的芯片、宿主节点(包括源宿主节点或者目标宿主节点)或者宿主节点(包括源宿主节点或者目标宿主节点)中的芯片。
通信装置1300包括处理单元1301和通信单元1302。可选的，通信装置1300还包括存储单元1303。
处理单元1301可以是具有处理功能的装置，可以包括一个或者多个处理器。处理器可以是通用处理器或者专用处理器等。处理器可以是基带处理器、或中央处理器。基带处理器可以用于对通信协议以及通信数据进行处理，中央处理器可以用于对装置(如，宿主节点、终端或芯片等)进行控制，执行软件程序，处理软件程序的数据。
通信单元1302可以是具有信号的输入(接收)或者输出(发送)的装置，用于与其他网络设备或者设备中的其他器件进行信号的传输。
存储单元1303可以是具有存储功能的装置，可以包括一个或者多个存储器。
可选的，处理单元1301、通信单元1302和存储单元1303通过通信总线相连。
可选的，存储单元1303可以独立存在，通过通信总线与处理单元1301相连。存储单元1303也可以与处理单元1301集成在一起。
可选的，通信装置1300可以是本申请实施例的终端或者宿主节点中的芯片。通信单元1302可以是输入或者输出接口、管脚或者电路等。存储单元1303可以是寄存器、缓存或者RAM等，存储单元1303可以和处理单元1301集成在一起；存储单元1303可以是ROM或者可存储静态信息和指令的其他类型的静态存储设备，存储单元1303可以与处理单元1301相独立。可选的，随着无线通信技术的发展，收发机可以被集成在通信装置1300上，例如通信单元1302集成了图10所示的收发器612。
在一种可能的设计中，处理单元1301可以包括指令，所述指令可以在所述处理器上被运行，使得所述通信装置1300执行上述实施例中终端或者宿主节点的方法。
在又一种可能的设计中，存储单元1303上存有指令，所述指令可在所述处理单元1301上被运行，使得所述通信装置1300执行上述实施例中终端或者宿主节点的方法。可选的，所述存储单元1303中还可以存储有数据。可选的，处理单元1301中也可以存储指令和/或数据。
通信装置1300可以是本申请实施例中的终端。终端的示意图可以如图10所示。可选的，装置1300的通信单元1302可以包括终端的天线和收发机，例如图10中的天线和收发机。可选的，通信单元1302还可以包括输出设备和输入设备，例如图10中的输出设备和输入设备。
通信装置1300可以是本申请实施例中的终端或者终端的芯片时，通信装置1300 可以实现上述方法实施例中的终端实现的功能。
通信装置1300可以是本申请实施例中的中继节点或者中继节点的芯片时，通信装置1300可以实现上述方法实施例中的中继节点实现的功能。
通信装置1300可以是本申请实施例中的接入网设备(例如源接入网设备或者目标接入网设备)的芯片时，通信装置1300可以实现上述方法实施例中的宿主节点的功能。
上面介绍了本申请实施例的方法流程图，要理解的是，终端可以存在与终端的方法或者步骤对应的功能单元(means)，中继节点可以存在与中继节点的方法或者步骤对应的功能单元，源宿主节点(例如CU和/或DU)可以存在与源宿主节点的方法(例如CU和/或DU)或者步骤对应的功能单元，目标宿主节点(例如CU和/或DU)可以存在与目标宿主节点(例如CU和/或DU)的方法或者步骤对应的功能单元，源宿主节点的CU可以存在与源宿主节点的CU的方法或者步骤对应的功能单元，另外中继系统中的其他节点可以存在与该其他节点对应的功能单元。以上模块或单元的一个或多个可以软件、硬件或二者结合来实现。当以上任一模块或单元以软件实现的时候，所述软件以计算机程序指令的方式存在，并被存储在存储器中，处理器可以用于执行所述程序指令以实现以上方法流程。
本申请中的处理器可以包括但不限于以下至少一种：中央处理单元(central processing unit，CPU)、微处理器、数字信号处理器(DSP)、微控制器(microcontroller unit，MCU)、或人工智能处理器等各类运行软件的计算设备，每种计算设备可包括一个或多个用于执行软件指令以进行运算或处理的核。该处理器可以是个单独的半导体芯片，也可以跟其他电路一起集成为一个半导体芯片，例如，可以跟其他电路(如编解码电路、硬件加速电路或各种总线和接口电路)构成一个SoC(system on a chip，片上系统)，或者也可以作为一个专用集成电路(application-specific integrated circuit，ASIC)的内置处理器集成在所述ASIC当中，该集成了处理器的ASIC可以单独封装或者也可以跟其他电路封装在一起。该处理器除了包括用于执行软件指令以进行运算或处理的核外，还可进一步包括必要的硬件加速器，如现场可编程门阵列(field programmable gate array，FPGA)、可编程逻辑器件(programmable logic device，PLD)、或者实现专用逻辑运算的逻辑电路。
本申请实施例中的存储器，可以包括如下至少一种类型：只读存储器(read-only memory，ROM)或可存储静态信息和指令的其他类型的静态存储设备，随机存取存储器(random access memory，RAM)或者可存储信息和指令的其他类型的动态存储设备，也可以是电可擦可编程只读存储器(electrically erasable programmabler-only memory，EEPROM)。在某些场景下，存储器还可以是只读光盘(compact disc read-only memory，CD-ROM)或其他光盘存储、光碟存储(包括压缩光碟、激光碟、光碟、数字通用光碟、蓝光光碟等)、磁盘存储介质或者其他磁存储设备、或者能够用于携带或存储具有指令或数据结构形式的期望的程序代码并能够由计算机存取的任何其他介质，但不限于此。
该总线除包括数据总线之外，还可以包括电源总线、控制总线和状态信号总线等。 但是为了清楚说明起见，在图中将各种总线都标为总线。
在实现过程中，上述方法的各步骤可以通过处理器中的硬件的集成逻辑电路或者软件形式的指令完成。结合本申请实施例所公开的方法的步骤可以直接体现为硬件处理器执行完成，或者用处理器中的硬件及软件模块组合执行完成。软件模块可以位于随机存储器，闪存、只读存储器，可编程只读存储器或者电可擦写可编程存储器、寄存器等本领域成熟的存储介质中。该存储介质位于存储器，处理器读取存储器中的信息，结合其硬件完成上述方法的步骤。为避免重复，这里不再详细描述。
根据本申请实施例提供的方法，本申请实施例还提供一种系统，其包括前述的装置和一个或多于一个的网络设备。
还应理解，本文中涉及的第一、第二、第三、第四以及各种数字编号仅为描述方便进行的区分，并不用来限制本申请实施例的范围，该数字编号可以替代为其他数字编号。
应理解，本文中术语“和/或”，仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。另外，本文中字符“/”，一般表示前后关联对象是一种“或”的关系。
应理解，在本申请的各种实施例中，上述各过程的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本申请实施例的实施过程构成任何限定。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各种说明性逻辑块(illustrative logical block)和步骤(step)，能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。
在本申请所提供的几个实施例中，应该理解到，所揭露的系统、装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个系统，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。
在上述实施例中，可以全部或部分地通过软件、硬件、固件或者其任意组合来实现。当使用软件实现时，可以全部或部分地以计算机程序产品的形式实现。所述计算机程序产品包括一个或多个计算机指令。在计算机上加载和执行所述计算机程序指令时，全部或部分地产生按照本申请实施例所述的流程或功能。所述计算机可以是通用计算机、专用计算机、计算机网络、或者其他可编程装置。所述计算机指令可以存储在计算机可读存储介质中，或者从一个计算机可读存储介质向另一个计算机可读存储介质传输，例如，所述计算机指令可以从一个网站站点、计算机、服务器或数据中心通过有线(例如同轴电缆、光纤、数字用户线(digital subscriber line，DSL))或无线(例如红外、无线、微波等)方式向另一个网站站点、计算机、服务器或数据中心进行传输。所述计算机可读存储介质可以是计算机能够存取的任何可用介质或者是包 含一个或多个可用介质集成的服务器、数据中心等数据存储设备。所述可用介质可以是磁性介质(例如，软盘、硬盘、磁带)、光介质(例如，数字通用磁盘(digital versatile disc，DVD))、或者半导体介质(例如固态硬盘)等。
以上所述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以所述权利要求的保护范围为准。

Claims (57)

  1. 一种用于接入回传一体化IAB系统中的通信方法，其特征在于，所述方法包括：
    子节点通过父节点接收来自接入网设备的第一无线资源控制RRC重配置消息，所述第一RRC重配置消息包括免随机接入的指示；
    所述子节点启动定时器；
    所述子节点通过所述父节点向所述接入网设备发送第一RRC重配置完成消息；
    所述子节点从所述父节点接收第一指示信息，所述第一指示信息指示停止所述定时器；
    所述子节点停止所述定时器。
  2. 根据权利要求1所述的方法，其特征在于，所述第一指示信息为第一类型的媒体接入控制元素MAC CE，或者所述第一指示信息为携带竞争解决标识的MAC CE。
  3. 根据权利要求1或者2所述的方法，其特征在于，所述第一RRC重配置消息不包括所述子节点的小区无线网络临时标识；或者
    所述第一RRC重配置消息包括第二指示信息，所述第二指示信息指示所述子节点的小区无线网络临时标识不变；或者
    所述第一RRC重配置消息包括所述子节点接收所述第一RRC重配置消息之前的使用的小区无线网络临时标识。
  4. 根据权利要求1至3任一项方法所述的方法，还包括：
    所述父节点从所述接入网设备接收第三指示信息；
    响应于第三指示信息，所述父节点向所述子节点发送所述第一指示信息。
  5. 根据权利要求4所述的方法，其特征在于，所述第三指示信息包括所述子节点的标识。
  6. 根据权利要求1至5任一项所述的方法，其特征在于，所述接入网设备是所述子节点和所述父节点在群组切换过程中的目标接入网设备。
  7. 根据权利要求6所述的方法，其特征在于，所述方法还包括：
    所述父节点从所述接入网设备接收或者向所述子节点发送所述第一RRC重配置消息后，所述父节点接收来自所述接入网设备的第二RRC重配置消息，且所述父节点启动定时器。
  8. 根据权利要求7所述的方法，其特征在于，所述方法还包括：
    所述父节点从所述接入网设备接收或者向所述子节点发送所述第一RRC重配置消息后，所述父节点向源接入网设备发送第四指示信息，用以触发所述源接入网设备向所述父节点发送所述第二RRC重配置消息，所述源接入网设备为所述子节点和所述父节点在群组切换过程中的源接入网设备。
  9. 根据权利要求1-8任一项所述的方法，其特征在于，所述子节点为终端或者IAB节点，所述父节点为IAB节点。
  10. 一种用于接入回传一体化IAB系统中的通信方法，其特征在于，所述方法包括：
    父节点从接入网设备接收第一RRC重配置消息，所述第一RRC重配置消息包括免随机接入的指示；
    所述父节点向子节点发送所述第一RRC重配置消息，用以触发所述子节点启动定时器；
    所述父节点从所述子节点接收第一RRC重配置完成消息；
    所述父节点向所述接入网设备发送所述第一RRC重配置完成消息；
    所述父节点向所述子节点发送第一指示信息，所述第一指示信息指示停止所述定时器。
  11. 根据权利要求10所述的方法，其特征在于，所述方法还包括：
    所述父节点从所述接入网设备接收第二指示信息；
    响应于所述第二指示信息，所述父节点向所述子节点发送所述第一指示信息。
  12. 根据权利要求11所述的方法，其特征在于，所述第二指示信息包括所述子节点的标识。
  13. 根据权利要求10-12任一项方法所述的方法，其特征在于，所述第一指示信息为第一类型的媒体接入控制元素MAC CE，或者所述第一指示信息为携带竞争解决标识的MAC CE。
  14. 根据权利要求10-13任一项所述的方法，其特征在于，所述第一RRC重配置消息不包括所述子节点的小区无线网络临时标识；或者
    所述第一RRC重配置消息包括第三指示信息，所述第三指示信息指示所述子节点的小区无线网络临时标识不变；或者
    所述第一RRC重配置消息包括所述父节点向所述子节点发送所述第一RRC重配置消息之前，所述子节点的小区无线网络临时标识。
  15. 根据权利要求10至14任一项所述的方法，其特征在于，所述接入网设备是所述子节点在群组切换过程中的目标接入网设备。
  16. 根据权利要求15所述的方法，其特征在于，所述方法还包括：
    所述父节点从所述接入网设备接收或者向所述子节点发送所述第一RRC重配置消息后，所述父节点接收来自所述接入网设备第二RRC重配置消息，且所述父节点启动定时器。
  17. 根据权利要求16所述的方法，其特征在于，所述方法还包括：
    所述父节点从所述接入网设备接收或者向所述子节点发送所述第一RRC重配置消息后，所述父节点向源接入网设备发送第四指示信息，用以触发所述源接入网设备向所述父节点发送所述第二RRC重配置消息，所述源接入网设备为所述子节点和所述父节点在群组切换过程中的源接入网设备。
  18. 根据权利要求10-17任一项所述的方法，其特征在于，所述子节点为终端或者IAB节点，所述父节点为IAB节点。
  19. 一种用于接入回传一体化IAB系统中的通信方法，其特征在于，所述方法包括：
    接入网设备通过父节点向子节点发送第一无线资源控制RRC重配置消息，用以触发所述子节点启动定时器，所述第一RRC重配置消息包括免随机接入的指示；
    所述接入网设备通过所述父节点从所述子节点接收第一RRC重配置完成消息；
    所述接入网设备向所述父节点发送第二指示信息，以触发所述父节点向所述子节点发送第一指示信息，所述第一指示信息指示停止所述定时器。
  20. 根据权利要求19所述的方法，其特征在于，所述第二指示信息包括所述子节点的标识。
  21. 根据权利要求19或者20所述的方法，其特征在于，所述第一指示信息为第一类型的媒体接入控制元素MAC CE，或者所述第一指示信息为携带竞争解决标识的MAC CE。
  22. 根据权利要求19-21任一项所述的方法，其特征在于，所述第一RRC重配置消息不包括所述子节点的小区无线网络临时标识；或者
    所述第一RRC重配置消息包括第三指示信息，所述第三指示信息指示所述子节点的小区无线网络临时标识不变；或者
    所述第一RRC重配置消息包括所述接入网设备通过所述父节点向所述子节点发送所述第一RRC重配置完成消息之前，所述子节点的小区无线网络临时标识。
  23. 根据权利要求1至5任一项所述的方法，其特征在于，所述接入网设备是所述子节点在群组切换过程中的目标接入网设备。
  24. 根据权利要求23所述的方法，其特征在于，所述方法还包括：
    所述目标接入网设备从源接入网设备接收切换请求消息，所述切换请求消息包括以下一项或者多项：切换前所述子节点的小区无线网络临时标识，切换前所述子节点接入的小区的标识和所述子节点在网络拓扑中的层级信息，所述源接入网设备为所述子节点和所述父节点在群组切换过程中的源接入网设备。
  25. 根据权利要求24所述的方法，其特征在于，所述方法还包括：
    所述目标接入网设备根据所述层级信息确定所述定时器的时长；
    其中，所述第一RRC重配置消息包括所述定时器的时长的信息。
  26. 一种用于接入回传一体化IAB系统中的通信方法，其特征在于，所述方法包括：
    子节点接收来自接入网设备的第一无线资源控制RRC重配置消息；
    所述子节点根据所述第一RRC重配置消息进行切换；
    其中，所述子节点切换前的小区无线网络临时标识与切换后的小区无线网络临时标识相同。
  27. 根据权利要求26所述的方法，其特征在于，所述第一RRC重配置消息不包 括所述子节点的小区无线网络临时标识，或者所述第一RRC重配置消息包括第一指示信息，所述第一指示信息指示所述子节点的小区无线网络临时标识不变，或者所述第一RRC重配置消息包括所述子节点接收所述第一RRC重配置消息之前的使用的小区无线网络临时标识。
  28. 根据权利要求26或者27所述的方法，其特征在于，所述第一RRC重配置消息包括免随机接入的指示。
  29. 根据权利要求28所述的方法，其特征在于，所述方法还包括：
    所述子节点启动定时器；
    所述子节点通过父节点向所述接入网设备发送第一RRC重配置完成消息；
    所述子节点从所述父节点接收第二指示信息，所述第二指示信息指示停止所述定时器；
    所述子节点停止所述定时器。
  30. 根据权利要求29所述的方法，其特征在于，所述第二指示信息为第一类型的媒体接入控制元素MAC CE，或者所述第二指示信息为携带竞争解决标识的MAC CE。
  31. 根据权利要求29或者30任一项方法所述的方法，还包括：
    所述父节点从所述接入网设备接收第三指示信息；
    响应于第三指示信息，所述父节点向所述子节点发送所述第二指示信息。
  32. 根据权利要求31所述的方法，其特征在于，所述第三指示信息包括所述子节点的标识。
  33. 根据权利要求26至32任一项所述的方法，其特征在于，所述接入网设备是所述子节点和所述父节点在群组切换过程中的目标接入网设备。
  34. 根据权利要求33所述的方法，其特征在于，所述方法还包括：
    所述父节点从所述接入网设备接收或者向所述子节点发送所述第一RRC重配置消息后，所述父节点接收来自所述接入网设备的第二RRC重配置消息，且所述父节点启动定时器。
  35. 根据权利要求34所述的方法，其特征在于，所述方法还包括：
    所述父节点从所述接入网设备接收或者向所述子节点发送所述第一RRC重配置消息后，所述父节点向源接入网设备发送第四指示信息，用以触发源接入网设备向所述父节点发送所述第二RRC重配置消息，所述源接入网设备为所述子节点和所述父节点在群组切换过程中的源接入网设备。
  36. 根据权利要求1-8任一项所述的方法，其特征在于，所述子节点为终端或者IAB节点，所述父节点为IAB节点。
  37. 一种用于接入回传一体化IAB系统中的通信方法，其特征在于，所述方法包括：
    接入网设备获取第一无线资源控制RRC重配置消息；
    所述接入网设备向子节点发送第一RRC重配置消息；
    其中，所述第一RRC重配置消息用于所述子节点的切换，所述子节点切换前的小区无线网络临时标识与切换后的小区无线网络临时标识相同。
  38. 根据权利要求37所述的方法，其特征在于，所述第一RRC重配置消息不包括所述子节点的小区无线网络临时标识，或者所述第一RRC重配置消息包括第一指示信息，所述第一指示信息指示所述子节点的小区无线网络临时标识不变，或者所述第一RRC重配置消息包括所述子节点接收所述第一RRC重配置消息之前的使用的小区无线网络临时标识。
  39. 根据权利要求37或者38所述的方法，其特征在于，所述第一RRC重配置消息包括免随机接入的指示。
  40. 根据权利要求39所述的方法，其特征在于，所述方法还包括：
    所述接入网设备通过所述父节点从所述子节点接收第一RRC重配置完成消息；
    所述接入网设备向所述父节点发送第二指示信息，以触发所述父节点向所述子节点发送第三指示信息，所述第三指示信息指示停止所述定时器。
  41. 根据权利要求40所述的方法，其特征在于，所述第二指示信息包括所述子节点的标识。
  42. 根据权利要求40或者41所述的方法，其特征在于，所述第三指示信息为第一类型的媒体接入控制元素MAC CE，或者所述第三指示信息为携带竞争解决标识的MAC CE。
  43. 根据权利要求37至42任一项所述的方法，其特征在于，所述接入网设备是所述子节点在群组切换过程中的目标接入网设备。
  44. 根据权利要求43所述的方法，其特征在于，所述方法还包括：
    所述目标接入网设备从源接入网设备接收切换请求消息，所述切换请求消息包括以下一项或者多项：切换前所述子节点的小区无线网络临时标识，切换前所述子节点接入的小区的标识和所述子节点在网络拓扑中的层级信息，所述源接入网设备为所述子节点和所述父节点在群组切换过程中的源接入网设备。
  45. 根据权利要求44所述的方法，其特征在于，所述方法还包括：
    所述目标接入网设备根据所述层级信息确定所述定时器的时长；
    其中，所述第一RRC重配置消息包括所述定时器的时长的信息。
  46. 一种通信装置，其特征在于，包括至少一个处理器，所述至少一个处理器用于调用存储器中存储的程序，以执行权利要求1至3任一项或者26至30任一项所述的方法。
  47. 一种通信装置，其特征在于，包括至少一个处理器，所述至少一个处理器用于调用存储器中存储的程序，以执行权利要求10至18任一项所述的方法。
  48. 一种通信装置，其特征在于，包括至少一个处理器，所述至少一个处理器用于调用存储器中存储的程序，以执行权利要求19至25任一项或者权利要求37至45任一项所述的方法。
  49. 一种芯片，其特征在于，所述芯片包括处理器和通信接口，所述通信接口和所述处理器耦合，所述处理器用于运行计算机程序或指令，使得权利要求1至3任一项或者26至30任一项所述的方法被执行。
  50. 一种芯片，其特征在于，所述芯片包括处理器和通信接口，所述通信接口和所述处理器耦合，所述处理器用于运行计算机程序或指令，使得权利要求10至18任一项所述的方法被执行。
  51. 一种芯片，其特征在于，所述芯片包括处理器和通信接口，所述通信接口和所述处理器耦合，所述处理器用于运行计算机程序或指令，使得权利要求19至25任一项或者权利要求37至45任一项所述的方法被执行。
  52. 一种装置，其特征在于，所述装置用于执行权利要求1至3任一项或者26至30任一项所述的方法。
  53. 一种装置，其特征在于，所述装置用于执行权利要求10至18任一项所述的方法。
  54. 一种装置，其特征在于，所述装置用于执行权利要求19至25任一项或者权利要求37至45任一项所述的方法。
  55. 一种计算机可读存储介质，其特征在于，存储有用于实现权利要求1至3任一项、26至30任一项、10至18任一项、19至25任一项或者权利要求37至45任一项所述的方法的程序或者指令。
  56. 一种计算机程序产品，其特征在于，所述计算机程序产品包括指令，当所述指令被运行时，使得权利要求1至3任一项、26至30任一项、10至18任一项、19至25任一项或者权利要求37至45任一项所述的方法被执行。
  57. 一种通信系统，其特征在于，所述通信系统包括权利要求46或者49所述的装置，权利要求47或者50所述的装置，以及权利要求48或者51所述的装置中的一个或者多个。
PCT/CN2020/103893 2020-07-23 2020-07-23 一种用于接入回传一体化iab系统中的通信方法和通信装置 WO2022016473A1 (zh)

Priority Applications (9)

Application Number Priority Date Filing Date Title
KR1020237005378A KR20230041037A (ko) 2020-07-23 2020-07-23 통합된 액세스 및 백홀(iab) 시스템을 위한 통신 방법 및 통신 장치
AU2020459888A AU2020459888B2 (en) 2020-07-23 Communication method applied to integrated access and backhaul iab system and communication apparatus
BR112023001182A BR112023001182A2 (pt) 2020-07-23 2020-07-23 Método de comunicação aplicado a sistema de backhaul e acesso integrados iab e aparelho de comunicação
PCT/CN2020/103893 WO2022016473A1 (zh) 2020-07-23 2020-07-23 一种用于接入回传一体化iab系统中的通信方法和通信装置
CN202080105148.5A CN116097745A (zh) 2020-07-23 2020-07-23 一种用于接入回传一体化iab系统中的通信方法和通信装置
CA3189789A CA3189789A1 (en) 2020-07-23 2020-07-23 Communication method applied to integrated access and backhaul iab system and communication apparatus
JP2023504426A JP2023534851A (ja) 2020-07-23 2020-07-23 統合アクセスおよびバックホールｉａｂシステムに適用される通信方法および通信装置
EP20945967.6A EP4185005A4 (en) 2020-07-23 2020-07-23 COMMUNICATION METHOD AND DEVICE FOR AN INTEGRATED ACCESS AND BACKHAUL (IAB) SYSTEM
US18/156,560 US20230156848A1 (en) 2020-07-23 2023-01-19 Communication method applied to integrated access and backhaul iab system and communication apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2020/103893 WO2022016473A1 (zh) 2020-07-23 2020-07-23 一种用于接入回传一体化iab系统中的通信方法和通信装置

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US18/156,560 Continuation US20230156848A1 (en) 2020-07-23 2023-01-19 Communication method applied to integrated access and backhaul iab system and communication apparatus

Publications (1)

Publication Number Publication Date
WO2022016473A1 true WO2022016473A1 (zh) 2022-01-27

Family

ID=79729931

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/103893 WO2022016473A1 (zh) 2020-07-23 2020-07-23 一种用于接入回传一体化iab系统中的通信方法和通信装置

Country Status (8)

Country Link
US (1) US20230156848A1 (zh)
EP (1) EP4185005A4 (zh)
JP (1) JP2023534851A (zh)
KR (1) KR20230041037A (zh)
CN (1) CN116097745A (zh)
BR (1) BR112023001182A2 (zh)
CA (1) CA3189789A1 (zh)
WO (1) WO2022016473A1 (zh)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220132381A1 (en) * 2020-10-23 2022-04-28 At&T Intellectual Property I, L.P. User plane adaptation for mobile integrated access and backhaul
WO2024031230A1 (en) * 2022-08-08 2024-02-15 Apple Inc. Group rrc reestablishment in mobile iab nodes
WO2024066814A1 (zh) * 2022-09-29 2024-04-04 大唐移动通信设备有限公司 切换命令传输方法、设备、装置及存储介质

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220225060A1 (en) * 2021-01-14 2022-07-14 Qualcomm Incorporated Selective forwarding of rrc reconfiguration messages in iab
CN117057579B (zh) * 2023-08-31 2024-04-02 浙江万胜智通科技有限公司 一种分布式配电网的运行维护方法及系统

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110062428A (zh) * 2018-01-19 2019-07-26 中兴通讯股份有限公司 一种小区无线网络临时标识分配方法、装置及系统
CN110392403A (zh) * 2018-04-19 2019-10-29 华为技术有限公司 一种通信方法及装置
CN110784895A (zh) * 2018-07-31 2020-02-11 夏普株式会社 由用户设备执行的方法以及用户设备
CN110831095A (zh) * 2018-08-11 2020-02-21 华为技术有限公司 通信方法和通信装置
WO2020059633A1 (en) * 2018-09-20 2020-03-26 Sharp Kabushiki Kaisha Systems, Devices, and Methods for Handling Radio Link Failures in Wireless Relay Networks
WO2020090988A1 (en) * 2018-10-31 2020-05-07 Sharp Kabushiki Kaisha Methods and apparatus for using conditional handovers for wireless backhaul

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160381611A1 (en) * 2014-08-28 2016-12-29 Ntt Docomo, Inc. Base station and user equipment
US11191001B2 (en) * 2017-11-21 2021-11-30 Ualcomm Incorporated Handover schemes for millimeter wave (MMW) wireless communications
WO2019160343A1 (en) * 2018-02-14 2019-08-22 Lg Electronics Inc. Method and apparatus for performing uplink transmission with pre-allocated beams in wireless communication system
CN112823539B (zh) * 2018-09-08 2024-06-14 欧芬诺有限责任公司 回程链路连接信息

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110062428A (zh) * 2018-01-19 2019-07-26 中兴通讯股份有限公司 一种小区无线网络临时标识分配方法、装置及系统
CN110392403A (zh) * 2018-04-19 2019-10-29 华为技术有限公司 一种通信方法及装置
CN110784895A (zh) * 2018-07-31 2020-02-11 夏普株式会社 由用户设备执行的方法以及用户设备
CN110831095A (zh) * 2018-08-11 2020-02-21 华为技术有限公司 通信方法和通信装置
WO2020059633A1 (en) * 2018-09-20 2020-03-26 Sharp Kabushiki Kaisha Systems, Devices, and Methods for Handling Radio Link Failures in Wireless Relay Networks
WO2020090988A1 (en) * 2018-10-31 2020-05-07 Sharp Kabushiki Kaisha Methods and apparatus for using conditional handovers for wireless backhaul

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
ERICSSON: "Physical layer aspects of RACH-less HO", 3GPP DRAFT; R1-1905220 PHYSICAL LAYER ASPECTS OF RACH-LESS HO, 3RD GENERATION PARTNERSHIP PROJECT (3GPP), MOBILE COMPETENCE CENTRE ; 650, ROUTE DES LUCIOLES ; F-06921 SOPHIA-ANTIPOLIS CEDEX ; FRANCE, vol. RAN WG1, no. Xi’an, China; 20190408 - 20190412, 7 April 2019 (2019-04-07), Mobile Competence Centre ; 650, route des Lucioles ; F-06921 Sophia-Antipolis Cedex ; France , XP051700295 *
See also references of EP4185005A4 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220132381A1 (en) * 2020-10-23 2022-04-28 At&T Intellectual Property I, L.P. User plane adaptation for mobile integrated access and backhaul
WO2024031230A1 (en) * 2022-08-08 2024-02-15 Apple Inc. Group rrc reestablishment in mobile iab nodes
WO2024066814A1 (zh) * 2022-09-29 2024-04-04 大唐移动通信设备有限公司 切换命令传输方法、设备、装置及存储介质

Also Published As

Publication number Publication date
CN116097745A (zh) 2023-05-09
KR20230041037A (ko) 2023-03-23
EP4185005A4 (en) 2023-08-30
AU2020459888A1 (en) 2023-03-09
BR112023001182A2 (pt) 2023-04-04
CA3189789A1 (en) 2022-01-27
EP4185005A1 (en) 2023-05-24
JP2023534851A (ja) 2023-08-14
US20230156848A1 (en) 2023-05-18
CN116097745A8 (zh) 2024-05-24

Similar Documents

Publication Publication Date Title
WO2022016473A1 (zh) 一种用于接入回传一体化iab系统中的通信方法和通信装置
US10595239B2 (en) Data transmission method and device
JP7455998B2 (ja) 通信方法、装置、およびシステム
WO2021147107A1 (zh) 一种通信方法及装置
WO2022151400A1 (zh) 一种用于接入回传一体化iab系统中的通信方法和通信装置
EP4192101A1 (en) Node switching method and related device
US20230171651A1 (en) Logical channel lch configuration method, communication apparatus, and communication system
WO2019042205A1 (zh) 数据传输方法、相关装置及系统
US20240064607A1 (en) Communication method, apparatus, and system
WO2021026706A1 (zh) 一种f1接口管理方法及装置
WO2021159238A1 (zh) 一种数据处理方法、通信装置和通信系统
WO2022151298A1 (zh) 群组迁移方法、装置和系统
TW202033047A (zh) 行動性中斷減少之方法及其使用者設備
CN111586768A (zh) 切换方法及装置
WO2023241658A1 (zh) 一种通信方法、装置及计算机可读存储介质
WO2022041085A1 (zh) 回传配置信息的更新或者释放方法及相关产品
WO2023011621A1 (zh) 一种通信方法及通信装置
WO2023227090A1 (zh) 用于辅小区组的小区更新方法及装置、存储介质
WO2024093833A1 (zh) 一种通信方法和通信装置
WO2022027653A1 (zh) 信息传输方法、通信装置及存储介质
WO2024093735A1 (zh) 一种调度请求处理方法及装置
CN117793821A (zh) 一种通信方法、通信设备、介质及程序产品
WO2016101468A1 (zh) 移动性管理方法及装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20945967

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2023504426

Country of ref document: JP

Kind code of ref document: A

Ref document number: 3189789

Country of ref document: CA

REG Reference to national code

Ref country code: BR

Ref legal event code: B01A

Ref document number: 112023001182

Country of ref document: BR

ENP Entry into the national phase

Ref document number: 20237005378

Country of ref document: KR

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2020945967

Country of ref document: EP

Effective date: 20230215

ENP Entry into the national phase

Ref document number: 2020459888

Country of ref document: AU

Date of ref document: 20200723

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 112023001182

Country of ref document: BR

Kind code of ref document: A2

Effective date: 20230123