WO2022233190A1 - 接入回传一体化网络中的切换的方法、设备和介质 - Google Patents

接入回传一体化网络中的切换的方法、设备和介质 Download PDF

Info

Publication number
WO2022233190A1
WO2022233190A1 PCT/CN2022/081715 CN2022081715W WO2022233190A1 WO 2022233190 A1 WO2022233190 A1 WO 2022233190A1 CN 2022081715 W CN2022081715 W CN 2022081715W WO 2022233190 A1 WO2022233190 A1 WO 2022233190A1
Authority
WO
WIPO (PCT)
Prior art keywords
iab
host
node
handover
iab node
Prior art date
Application number
PCT/CN2022/081715
Other languages
English (en)
French (fr)
Inventor
孙飞
朱元萍
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
Publication of WO2022233190A1 publication Critical patent/WO2022233190A1/zh

Links

Images

Classifications

    • 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
    • H04W36/0011—Control or signalling for completing the hand-off for data sessions of end-to-end connection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • 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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/16—Performing reselection for specific purposes

Definitions

  • the present disclosure relates to the field of wireless local area networks, and more particularly, to a method, apparatus and medium for handover in an integrated access and backhaul network.
  • the fifth generation (5G) mobile communication system puts forward more stringent requirements for various performance indicators of the network. For example, the capacity is required to be increased by 1000 times, with wider coverage requirements, and it requires ultra-high reliability and ultra-low latency.
  • the capacity is required to be increased by 1000 times, with wider coverage requirements, and it requires ultra-high reliability and ultra-low latency.
  • the use of high-frequency small cells to form a network is becoming more and more popular.
  • the propagation characteristics of high-frequency carriers are poor, the attenuation is severe due to occlusion, and the coverage is not wide, so a large number of small cells need to be densely deployed.
  • IAB integrated access and backhaul
  • 5G 5th Generation
  • IAB technology has been widely used.
  • both the access link (Access Link) and the backhaul link (Backhaul Link) adopt the wireless transmission scheme, so the deployment of optical fibers for a large number of dense small cells can be reduced.
  • the present disclosure provides a handover scheme in an Integrated Backhaul Access (IAB) network.
  • IAB Integrated Backhaul Access
  • a handover method is provided.
  • the first IAB node determines that the conditions for switching from the first IAB host to the second IAB host have been met. Then, the first IAB node sends an instruction to switch to the second IAB host to the next-hop communication device to instruct the next-hop communication device to switch to the second IAB host, or sends an instruction for switching to the second IAB host to the first IAB host. ask.
  • the downstream IAB node or user equipment can be switched to the target IAB host together with the upstream node in time, thereby ensuring service continuity sex.
  • the first IAB node in response to the first IAB node receiving the handover completion indication from the next-hop communication device, the first IAB node performs the handover to the second IAB host. In this way, the probability of a successful handover can be further improved, and the efficiency of the handover operation can be improved.
  • the handover to the second IAB host includes index information with pre-configured information of the target cell controlled by the second IAB host, so that the next-hop communication device validates the pre-configuration information for handover to the target cell.
  • the indication to switch to the second IAB host is controlled by the first IAB node via the Backhaul Adaptation Protocol (BAP) layer Control Packet Data Unit (PDU) or Medium Access Control (MAC) Control Element (CE) Sent to the next-hop communication device.
  • BAP Backhaul Adaptation Protocol
  • PDU Packet Data Unit
  • MAC Medium Access Control
  • CE Control Element
  • the first IAB node where the first IAB node sends a request to the first IAB host to switch to the second IAB host, the first IAB node receives the first IAB node's next-hop communication from the first IAB host Following the indication that the device has switched to the second IAB host, the switch to the second IAB host is performed. Thereby, the probability of a successful handover can be further improved, and the efficiency of the handover operation can be improved.
  • a handover method is provided.
  • the second IAB node receives an indication from the previous hop IAB node to switch from the first IAB host to the second IAB host. Then, the second IAB node forwards the instruction of switching from the first IAB host to the second IAB host to the downstream communication device, so as to instruct the downstream communication device to switch from the first IAB host to the second IAB host.
  • the second IAB node performs the handover to the second IAB host in response to the second IAB node receiving an indication from the next-hop communication device that the handover is complete.
  • the instruction to switch from the first IAB host to the second IAB host includes index information of the pre-configuration information received by the second IAB node from the first IAB host, the index information being the same as that controlled by the second IAB host associated with the target cell. Also, the second IAB node validates the pre-configuration information for handover to the target cell.
  • a switching device in a third aspect of the present disclosure, includes a condition determination module and a first transmission module.
  • the condition determination module is configured to determine, by the first IAB node, that a condition for switching from the first IAB host to the second IAB host has been satisfied.
  • the first sending module is configured to send an indication of switching to the second IAB host to the next-hop communication device through the first IAB node to instruct the next-hop communication device to switch to the second IAB host, or to send the first IAB host to the first IAB host for switching. A request to the second IAB host.
  • the device when the first sending module is configured to send an instruction to switch to the second IAB host through the first IAB node to the next-hop communication device, the device further includes a first switching module, the first The handover module is configured to perform handover to the second IAB host by the first IAB node in response to the first IAB node receiving an indication of handover completion from the next-hop communication device.
  • the handover to the second IAB host includes index information with pre-configured information of the target cell controlled by the second IAB host, so that the next-hop communication device validates the pre-configuration information for handover to the target cell.
  • the indication to switch to the second IAB host is sent by the first IAB node to the next-hop communication device through the backhaul adaptation protocol BAP layer control packet data unit PDU or medium access control MAC control element CE.
  • the device when the first sending module is configured to send a request to the first IAB host to switch to the second IAB host through the first IAB node, the device further includes an instruction receiving module and a second switching module .
  • the indication receiving module is configured to receive, via the first IAB node, an indication from the first IAB host that the next-hop communication device of the first IAB node has switched to the second IAB host.
  • the second handover module is configured to perform a handover to the second IAB host by the first IAB node.
  • a switching device in a fourth aspect of the present disclosure, includes a first receiving module and a forwarding module.
  • the first receiving module is configured to receive, through the second IAB node, an indication of switching from the first IAB host to the second IAB host from the previous hop IAB node.
  • the forwarding module is configured to forward the instruction of switching from the first IAB host to the second IAB host to the downstream communication device through the second IAB node, so as to instruct the downstream communication device to switch from the first IAB host to the second IAB host.
  • the apparatus further includes a first switching module.
  • the first handover module is configured to perform the handover to the second IAB host by the second IAB node in response to the second IAB node receiving an indication of handover completion from the next-hop communication device.
  • the instruction to switch from the first IAB host to the second IAB host includes index information of the pre-configuration information received by the second IAB node from the first IAB host, the index information being the same as that controlled by the second IAB host associated with the target cell.
  • the first handover module includes a configuration validation module, and the configuration validation module is configured to validate the pre-configuration information through the second IAB node to handover to the target cell.
  • an IAB system in a fifth aspect of the present disclosure, includes a first IAB node and a second IAB node.
  • the first IAB node is configured to perform the method according to the first aspect of the present disclosure.
  • the second IAB node is configured to perform the method according to the second aspect of the present disclosure.
  • a communication device in a sixth aspect of the present disclosure, includes a processor coupled to a memory storing instructions. The instructions, when executed by a processor, cause a method according to the first or second aspect of the present disclosure to be performed.
  • a computer-readable storage medium having a program stored thereon, at least part of the program, when executed by a processor in a device, causes the device to perform the first or second aspect of the present disclosure Methods.
  • a chip comprising a processing circuit configured to perform a method according to the first or second aspect of the present disclosure.
  • a computer program product storing a computer program, at least part of the program, when executed by a processor in a device, causing the device to perform the method according to the first or second aspect of the present disclosure.
  • FIG. 1 shows an example scenario of wireless relay utilizing an IAB network
  • Figure 2 shows an example process of switching IAB hosts in a top-down order in an IAB network
  • Figure 3 shows an example process of switching IAB hosts in a bottom-up order in an IAB network
  • Figure 4 illustrates another example process of bottom-up switching of IAB hosts initiated from an intermediate IAB node in an IAB network
  • FIG. 5 illustrates an example environment in which embodiments of the present disclosure may be implemented
  • Figure 6a illustrates an example architecture of a control plane protocol stack of an IAB network in accordance with certain embodiments of the present disclosure
  • Figure 6b illustrates an example architecture of a user plane protocol stack of an IAB network in accordance with certain embodiments of the present disclosure
  • FIG. 7 shows a flowchart of a handover method implemented at an IAB node that initiates a cross-IAB home handover, according to certain embodiments of the present disclosure
  • FIG. 8 illustrates a flowchart of a handover method implemented at a communication device downstream of an IAB node that initiates a cross-IAB home handover in accordance with certain embodiments of the present disclosure
  • FIG. 9 illustrates an example handover process performed in the environment shown in FIG. 5 in accordance with certain embodiments of the present disclosure
  • Figure 10 illustrates an example handover process performed in the environment shown in Figure 5 in accordance with certain embodiments of the present disclosure
  • FIG. 11 shows a flowchart of a handover method implemented at an IAB host according to certain embodiments of the present disclosure
  • FIG. 12 illustrates an example handover process centrally controlled by an IAB host in the environment shown in FIG. 5 in accordance with certain embodiments of the present disclosure
  • FIG. 13 shows a schematic structural block diagram of an apparatus at an IAB node that initiates a cross-IAB host handover according to some embodiments of the present disclosure
  • FIG. 14 shows a schematic structural block diagram of an apparatus at a downstream communication device of an IAB node that initiates a cross-IAB hosting handover according to some embodiments of the present disclosure
  • FIG. 15 shows a schematic structural block diagram of an apparatus at an IAB host according to some embodiments of the present disclosure
  • FIG. 16 shows a block diagram of a device in which certain embodiments of the present disclosure may be implemented.
  • the term “including” and variations thereof are open inclusive, ie “including but not limited to”.
  • the term “based on” is “based at least in part on.”
  • the term “one embodiment” means “at least one embodiment”; the term “another embodiment” means “at least one additional embodiment”. Relevant definitions of other terms will be given in the description below.
  • an IAB node acts as a relay node RN (Relay Node), which can provide wireless access services for user equipment (User Equipment, UE).
  • the service data of the UE is transmitted by the IAB node connected to the IAB donor (IAB donor) through the wireless backhaul link.
  • the IAB donor may also be referred to as a donor node (donor node) or a donor base station, such as a donor next-generation base station (DgNB) or a donor evolved base station (DeNB).
  • DgNB donor next-generation base station
  • DeNB donor evolved base station
  • one or more transmission paths exist between the UE and the IAB host, and each transmission path may contain one or more IAB nodes.
  • Each IAB node needs to maintain the wireless backhaul link facing the parent node, and also needs to maintain the wireless link with the child node.
  • FIG. 1 shows an example scenario 100 of wireless relay utilizing an IAB network.
  • UE 101-1 and UE 101-2 may be connected to IAB nodes 102-1, 102-2, 102-3, 102-4 and 102-5 through radio access links, Thereby connecting to the IAB host 103 via a wireless backhaul link.
  • the IAB nodes 102-1, 102-2, 102-3, 102-4 and 102-5 may be connected to a core network, eg to a 5G core network (5GC) (not shown in Figure 1).
  • 5GC 5G core network
  • each transmission path may include IAB nodes 102-1, 102-2 , multiple IAB nodes in 102-3, 102-4 and 102-5.
  • IAB node 102-1 its child node is the UE 101-1, so there is a radio access link between the IAB node 102-1 and the child node (ie, the UE 101-1).
  • IAB node 102-2 its child nodes are other IAB nodes 102-1 or 102-5, so there is wireless backhaul between this IAB node 102-2 and the child nodes (ie, IAB node 102-1 or 102-5) link.
  • UE 101-2 accesses IAB node 102 through the wireless access link -5, IAB node 102-5 is connected to IAB node 102-4 through a wireless backhaul link, IAB node 102-4 is connected to IAB node 102-3 through a wireless backhaul link, and IAB node 102-3 is wirelessly backhauled
  • the link connects to the IAB host 103 .
  • the term "access IAB node” may refer to an IAB node accessed by a UE, and the term “intermediate IAB node” may refer to an IAB node that provides wireless backhaul services to the UE or IAB node.
  • IAB node 102-5 is the access The IAB node, the IAB node 102-4 and the IAB node 102-3 are intermediate IAB nodes. It should be understood that whether the IAB node is an access IAB node or an intermediate IAB node is not fixed and needs to be determined according to a specific application scenario.
  • the terms “upstream”, “downstream”, “previous hop” and “next hop” may refer to the direction of data flow in the backhaul link.
  • UE 101-2 ⁇ IAB node 102-5 ⁇ IAB node 102-4 ⁇ IAB node 102-3 ⁇ IAB host 103 UE 101-2 and IAB node 102-5 may be considered to be in the IAB Downstream of node 102-4, and IAB node 102-5 may be considered a next-hop node to IAB node 102-4.
  • the next-hop node is also called a child node, and the previous-hop node is also called a parent node.
  • the downstream nodes may include child nodes, grandchild nodes, etc.
  • the upstream nodes include ancestor nodes such as parent nodes.
  • IAB nodes can be implemented through a distributed architecture.
  • the IAB node node may include an MT (mobile termination, mobile terminal) part and a DU (distributed unit, distributed unit) part, also referred to as IAB-MT and IAB-DU, respectively.
  • MT mobile termination, mobile terminal
  • DU distributed unit, distributed unit
  • IAB hosting can be implemented through a distributed architecture or through a centralized architecture.
  • the IAB host may be an access network element with a complete base station function, or may be an access network element in the form of a centralized unit (centralized unit, CU) and a distributed unit (distributed unit, DU) separated.
  • a centralized unit of the IAB host may be abbreviated as a host CU (donor CU, or directly referred to as a CU), and the distributed unit of the IAB host may be abbreviated as a host DU or a donor DU.
  • the services of the IAB node or the services of the UE connected to the IAB node may require different nodes for transmission.
  • the IAB-MT and the IAB-DU of a certain IAB node are managed by a certain IAB host CU (for example, denoted as IAB donor CU1)
  • the IAB node managed by the IAB donor CU1 can be used to transmit services.
  • IAB-MT and IAB-DU of an IAB node are respectively connected to two host CUs (denoted as IAB donor CU I and IAB donor CU2)
  • the IAB node jointly managed by IAB donor CU1 and IAB donor CU2 can be used to transmit business.
  • the IAB node managed by the IAB donor CU2 can be used to transmit services.
  • an IAB node needs to switch between different IAB hosts. For example, the IAB node needs to switch to the cell controlled by the target IAB host to obtain better communication quality.
  • the downstream node can also switch to the new IAB host to ensure the service continuity of the UE.
  • Various switching sequences are possible. For example, a top-down switching order, a bottom-up switching order, or an arbitrary order.
  • An example procedure for switching IAB hosts in an IAB network is discussed below with reference to FIGS. 2 and 3 .
  • FIG. 2 an example process 200 of switching IAB hosts in a top-down order in an IAB network is shown.
  • the process 200 includes an initial stage 201 , an intermediate stage 202 and a final stage 203 that switch from top to bottom.
  • Source IAB host 211 includes host CU 212 (labeled as CU1) and host DU 213 (labeled as donor DU1)
  • target IAB host 214 includes CU 215 (labeled as CU2) and donor DU 216 (labeled as donor DU2).
  • MT 222 (labeled MT1) and DU 223 (labeled DU1a) of IAB node 221 are connected to CU1
  • MT 225 (labeled MT2) and DU 226 (labeled DU2b) of IAB node 224 are connected to CU2
  • MT 228 (labeled MT3) and DU 229 (labeled DU3a) of IAB node 227 are connected to CU1.
  • the IAB node 227 is handed over from the IAB host 211 to the IAB host 214 before the downstream node UE 230.
  • IAB node 227 enables DU 232 (labeled DU3b) controlled by CU2.
  • DU3b may first establish a communication interface (eg, F1 interface) with CU2.
  • CU1 can assign an IP address to DU3b, and tell DU3b that this IP address is to be used for communication with CU2 and not for other purposes, eg, not to communicate with source CU1.
  • the IAB node 227 when it receives the IP address, it can determine that it is sent by the target CU2 and communicated with the DU3b. As shown in Figure 2, when MT3 switches from source CU1 to target CU2, DU3a is still connected to CU1. In this case, the IAB node 227 still needs to communicate with CU1. Therefore, the relevant data packets need to pass through the transmission path of the IAB node 227, the IAB node 224 and the Donor DU2. In addition, data packets will also be transmitted via the IP network between Donor DU2 and CU1.
  • the MT3 of the IAB node 227 is handed over from the source CU1 to the target CU2, and the UE 230 is also handed over from the source CU1 to the target CU2.
  • FIG. 3 an example process 300 of switching IAB hosts in a bottom-up order in an IAB network is shown.
  • the bottom-up handover process 300 may include an initial stage 201 , an intermediate stage 302 and a final stage 203 of the bottom-up handover.
  • the initial stage 201 and the final stage 203 are the same as those shown in FIG. 2 , so the specific details will not be repeated.
  • the IAB node 227 is handed over from the IAB host 211 to the IAB host 214 after the downstream node UE 230.
  • the IAB node performing the handover is the access IAB node, and its child nodes only include UEs.
  • the IAB node performing the handover may be an intermediate IAB node that can provide wireless backhaul for other IAB nodes. An example process of switching IAB hosts in this scenario is discussed below with reference to FIG. 4 .
  • FIG. 4 illustrates another example process 400 for bottom-up switching of IAB hosting from an intermediate IAB node in an IAB network.
  • Process 400 includes an initial stage 401 , a first intermediate stage 402 , a second intermediate stage 403 and a final stage 404 .
  • the intermediate IAB node 227 confirms the handover from the IAB host 211 to the IAB host 214, ie from the IAB node 221 connected to CU1 to the IAB node 224 connected to CU2.
  • the IAB node 227 and its downstream IAB node 410 and the UE 230 need to be handed over to the IAB node 224 together.
  • IAB node 424 includes MT 425 (labeled MT4) and DU 426 (labeled DU4a) controlled by CU1 and DU 427 (labeled DU4b) controlled by CU2.
  • DU4a and DU4b belong to the same IAB node 424, but are controlled by different CUs and have different configurations. Examples of configuration may include configuration information such as topology management, routing management, and quality of service (QoS) management.
  • the configuration information may be pre-configured by the CU. For example, it is configured through Radio Resource Control (RRC) or F1 Application Protocol (F1AP) information.
  • RRC Radio Resource Control
  • F1AP F1 Application Protocol
  • the IAB node 424 first enables DU4b, and the specific process is similar to the process of enabling the DU3b by the IAB node 227 described above with reference to FIG. 2, and thus will not be repeated.
  • the UE 230 switches from DU4a controlled by CU1 to DU4b controlled by CU2, while MT4 is still connected to CU1.
  • the MT4 of the parent node IAB node 424 of the UE 230 switches from DU3a to DU3b.
  • the corresponding configuration of DU3b is activated accordingly. In this manner, the IAB node 424 switches to the IAB host 214 .
  • the MT3 of the parent node IAB node 227 of the IAB node 424 is handed over from DU1a to DU2b.
  • the corresponding configuration of DU2b is activated accordingly.
  • the IAB node 227 switches to the IAB host 214 .
  • the IAB node 227 and its downstream IAB node 424 and the UE 230 complete the process of switching from the IAB host 211 to the IAB host 214.
  • the IAB node 227 when the IAB node 227 confirms the handover from the IAB host 211 to the IAB host 214, the downstream nodes of the IAB node 227 (the IAB node 424 and the UE 230) are handed over to the IAB host 214 together.
  • the IAB node In the process of conditional handover (CHO), the IAB node can confirm that the handover needs to be performed based on the handover condition being satisfied.
  • the switching condition may be preconfigured by the network, and configuration information corresponding to the switching condition is also preconfigured.
  • the handover condition being satisfied may be determined based on the signal quality of the serving cell and neighboring cells.
  • the IAB node can handover to the cell controlled by the target IAB host without network triggering.
  • the downstream node e.g., IAB node 424 or UE 230
  • the downstream node does not necessarily reach the handover condition.
  • downstream nodes may not switch automatically.
  • the downstream node should also switch to the target IAB host in time to avoid the situation where the upstream node has been switched but the downstream node has not been switched, thereby ensuring service continuity. Therefore, there is a need for a solution that enables the downstream node to switch to the target IAB host together with the upstream node in a timely manner.
  • Embodiments of the present disclosure propose a mechanism for handover in an IAB network. According to this mechanism, when an IAB node determines that the conditions for switching from one IAB host (referred to as “first IAB host”) to another IAB host (referred to as “second IAB host”) have been satisfied, the IAB node moves to the next The hop communication device (which may be another IAB node or UE) sends an indication to switch to the second IAB host or sends a request to the first IAB host to switch to the second IAB host.
  • the hop communication device which may be another IAB node or UE
  • the downstream node may receive an instruction to switch from the first IAB host to the second IAB host from the previous hop IAB node or the first IAB host, and perform the handover to the second IAB host. In this way, the downstream node can switch to the target IAB host in time. In this way, the synchronization of switching between upstream and downstream nodes is maintained, thereby ensuring service continuity.
  • FIG. 5 illustrates an example environment 500 in which embodiments of the present disclosure may be implemented.
  • environment 500 may be part of an IAB network including UE 510, IAB nodes 520, 530 and 540, and IAB hosts 550 and 560.
  • UE 510 may communicate with IAB hosts 550 or 560 via IAB nodes 520, 530 and 540.
  • IAB node 520 is an access IAB node
  • IAB nodes 530 and 540 are intermediate IAB nodes.
  • wireless communication is enabled between the UE, the IAB node, and the IAB host. The communication may follow any suitable communication technology and corresponding communication standard.
  • UEs, IAB nodes and IAB hosts shown in FIG. 5 are only examples and not limitations. Depending on the specific implementation and scenario, there may be any suitable number of UEs, IAB nodes and IAB hosts, which may have any suitable connection or coupling relationship.
  • IAB nodes 520, 530 and 540 and IAB hosts 550 and 560 are all implemented in a distributed fashion.
  • IAB node 520 may include DU 521 and MT 522
  • IAB node 530 may include DU 531 and MT 532
  • IAB node 540 may include DU 541 and MT 542.
  • IAB host 550 may include host DU 551 and CU 552
  • IAB host 560 may include host DU 561 and CU 562. Both the CUs 552 and 562 may be in a form in which the control plane (CP) and the user plane (UP) are separated.
  • CP control plane
  • UP user plane
  • CU 552 may include one CU-CP 553 and one CU-UP 554, and CU 562 may include one CU-CP 563 and one CU-UP 564. It should be understood that one CU shown in FIG. 5 includes one CU-UP is only an example, not a limitation. In some embodiments, one CU may include one CU-CP and multiple CU-UPs.
  • the IAB network may be a standalone (SA) IAB network or a non-standalone (NSA) IAB network.
  • SA mode the CU-CP 553 can connect to control plane network elements in the 5GC 590, such as access and mobility management functions (AMF), through the NG control plane interface NG-C.
  • AMF access and mobility management functions
  • the CU-UP 554 can be connected to user plane network elements in the 5GC 590 through the NG user plane interface NG-U, such as a user plane function (UPF).
  • the 5GC 590 can be connected to the 5G base station gNB 570 through the NG interface.
  • the gNB 570 may establish a user plane and/or control plane interface with the 5GC 590.
  • gNB 570 and IAB host 550 may provide dual connectivity services for IAB nodes (eg, IAB node 540).
  • IAB nodes eg, IAB node 540
  • the gNB 570 may play the role of the primary base station or the role of the secondary base station of the IAB node 540.
  • the CU-UP 554 can be connected to the 4G core network EPC 580 through the S1 user plane interface S1-U, for example, to a service gateway (serving gateway, SGW).
  • the NSA mode is also called Evolved Universal Terrestrial Radio Access (E-UTRA) New Radio (NR) Dual Connectivity or EN-DC mode.
  • the EPC 580 is connected to the LTE base station MeNB 570 through the S1 interface (including the S1 interface user plane and the S1 interface control plane).
  • MeNB 570 and IAB host 540 may provide dual connectivity services for an IAB node (eg, IAB node 540).
  • MeNB 570 may act as the primary base station for IAB node 540.
  • F1 interface (not shown in FIG. 5 ) for communication between the DUs 521, 531 and 541 and the CUs 552 and 560 of each IAB node 520, 530 and 540.
  • control plane protocol stack and the user plane protocol stack of an IAB network is described below with reference to Figures 6a and 6b.
  • Figure 6a illustrates an example architecture 600 of a control plane protocol stack of an IAB network in accordance with certain embodiments of the present disclosure.
  • a Uu interface is established between the UE 510 and the DU 521 of the IAB node 520, and the peer-to-peer protocol layers include an RLC layer, a MAC layer, and a PHY layer.
  • An F1-C interface is established between the DU 521 of the IAB node 520 and the CU 552 of the IAB host 550, and the peer-to-peer protocol layers include an F1 application protocol (F1 application protocol, F1AP) layer, a stream control transmission protocol (Stream Control Transmission Protocol, SCTP) )Floor.
  • F1 application protocol F1 application protocol, F1AP
  • SCTP stream Control Transmission Protocol
  • the host DU 551 and the CU 552 in the IAB host 550 are connected by wire, and the peer-to-peer protocol layers include an internet protocol IP (internet protocol) layer, L2 and L1.
  • Backhaul (BL) links are established between the IAB node 520 and the IAB node 530, between the IAB node 530 and the IAB node 540, and between the IAB node 540 and the host DU 551 in the IAB host 550, and the peer-to-peer protocol
  • the layers include a backhaul adaptation protocol (Bakhaul Adaptation Protocol, BAP) layer, an RLC layer, a MAC layer, and a PHY layer.
  • BAP backhaul adaptation protocol
  • a peer-to-peer RRC layer and a PDCP layer are established between the UE 510 and the CU 552, and a peer-to-peer IP layer is established between the DU 521 of the IAB node 520 and the host DU 551 in the IAB host 550.
  • the control plane protocol stack of the IAB network is compared with the control plane protocol stack of the single air interface.
  • the DU accessing the IAB node realizes the function of the gNB-DU of the single air interface (that is, establishing a peer RLC layer, MAC layer with the UE). and the functions of the PHY layer, as well as the functions of the F1AP layer and SCTP layer that establish peering with the CU). That is, the DU connected to the IAB node in the IAB network realizes the function of the gNB-DU with a single air interface, and the IAB donor CU (for example, CU 552) realizes the function of the gNB-CU with a single air interface.
  • RRC messages are encapsulated and transmitted in F1AP messages between the access IAB node and the IAB donor CU.
  • the UE 510 encapsulates the RRC message in a PDCP protocol data unit (protocol data unit, PDU), and sends it to the DU 521 of the IAB node 520 after being processed by the RLC layer, the MAC layer, and the PHY layer in sequence.
  • PDU protocol data unit
  • the DU 521 of the IAB node 520 obtains the PDCP PDU after being processed by the PHY layer, the MAC layer and the RLC layer in turn, encapsulates the PDCP PDU in the F1AP message, and sequentially processes the SCTP layer and the IP layer to obtain the IP packet.
  • the MT 522 sends the IP packet to the DU 531 of the IAB node 530 after being processed by the BAP layer, the RLC layer, the MAC layer and the PHY layer respectively.
  • the DU 531 of the IAB node 530 is sequentially processed by the PHY layer, the MAC layer, the RLC layer and the BAP layer to obtain an IP packet, and then the MT 532 of the IAB node 530 adopts an operation similar to the MT 522 to send the IP packet to the IAB node 540 Similarly, the MT 542 of the IAB node 540 sends the IP packet to the host DU 551 in the IAB host 550.
  • the IP packet is sent to the CU 552 of the IAB host 550, and the CU 552 sequentially processes the IP packet through the SCTP layer, the F1AP layer and the PDCP layer to obtain an RRC message.
  • the downstream direction is similar and will not be described here.
  • Figure 6b illustrates an example architecture 610 of a user plane protocol stack of an IAB network in accordance with certain embodiments of the present disclosure.
  • a Uu interface is established between the UE 510 and the DU 521 of the IAB node 520, and the peer-to-peer protocol layers include an RLC layer, a MAC layer, and a PHY layer.
  • the DU 521 of the IAB node 520 and the CU 552 of the IAB host 550 establish an F1-U interface, and the peer-to-peer protocol layers include the GPRS tunneling protocol for the user plane (GTP-U) layer, the user datagram protocol (user datagram protocol, UDP) layer.
  • GTP-U GPRS tunneling protocol for the user plane
  • UDP user datagram protocol
  • the host DU 551 and the CU 552 in the IAB host 550 are connected by wire, and the peer-to-peer protocol layers include the IP layer, L2 and L1.
  • BL links are established between the IAB node 520 and the IAB node 530, between the IAB node 530 and the IAB node 540, and between the IAB node 540 and the host DU 551 in the IAB host 550, and the peer-to-peer protocol layers include the BAP layer , RLC layer, MAC layer and PHY layer.
  • a peer-to-peer SDAP layer and a PDCP layer are established between the UE 510 and the CU 552, and a peer-to-peer IP layer is established between the DU 521 of the IAB node 520 and the host DU 551 in the IAB host 550.
  • 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 (for example, the IAB node 520) realizes part of the functions of the single air interface gNB-DU (that is, establishes with the terminal.
  • the DU of the IAB access node realizes the function of the single air interface gNB-DU; the IAB donor CU realizes the function of the single air interface gNB-CU.
  • the PDCP data packets are encapsulated and transmitted in the GTP-U tunnel between the access IAB node and the IAB donor CU (eg CU 552).
  • the GTP-U tunnel is established on the F1-U interface.
  • UE 510 the IAB nodes 520, 530 and 540 and the IAB host are shown in and described with reference to Figures 5 and 6a and 6b for purposes of illustration only and not intended to suggest any limitation.
  • 550 and 560 structure and protocol stack architecture.
  • IAB nodes and IAB hosts that may implement embodiments of the present disclosure may have any suitable other structures and any suitable other protocol stack architectures. Any structure and protocol architecture currently known and developed in the future for communication devices in an IAB network may be used herein, and the scope of the present disclosure is not limited in this regard.
  • IAB nodes 520, 530 and/or 540 may be implemented with a centralized architecture, eg, with full base station functionality, and likewise, IAB hosts 550 and 560 may be implemented centrally with full base station functionality Function.
  • IAB nodes 520 , 530 and 540 may perform conditional switching between IAB host 550 and IAB host 560 .
  • the IAB node 530 determines that the conditions for switching from the IAB host 550 to the IAB host 560 have been satisfied, it sends an instruction to switch to the IAB host 560 to the next-hop IAB node 520, or sends a switch to the IAB host 560 to the IAB host 550. ask.
  • the downstream IAB node 520 may perform the handover to the IAB host 560 based on the handover instruction from the previous hop IAB node 530 or the IAB host 550 . In this way, upstream and downstream nodes can perform handover synchronously, thereby ensuring service continuity.
  • FIG. 7 illustrates a flow diagram of a handover method 700 implemented at an IAB node that initiates a cross-IAB home handover, in accordance with certain embodiments of the present disclosure.
  • the method 700 may be performed by the IAB nodes 520, 530 or 540 in FIG. 5 .
  • the method 700 will be described below with reference to FIG. 5 in conjunction with a scenario where the IAB node 530 initiates a handover from the IAB host 550 to the IAB host 560 .
  • the first IAB node determines that the conditions for switching from the first IAB host (IAB host 550) to the second IAB host (IAB host 560) have been met.
  • the switching conditions can be pre-configured in the network.
  • the handover condition may be pre-configured by a network management system, such as an IAB host node.
  • the handover condition may be associated with the signal quality of the serving cell and neighbor cells. For example, it may be determined that the handover condition is satisfied based on the difference between the signal quality of the serving cell controlled by the first IAB donor and the signal quality of the neighbor cell controlled by the second IAB donor being lower than a predetermined threshold.
  • the threshold can also be pre-configured by the network management system.
  • the first IAB host is also referred to as the source IAB host
  • the second IAB host is also referred to as the target IAB host.
  • the cell controlled by the second IAB donor to which the first IAB node will be handed over is also referred to as the target cell.
  • the first IAB node sends an indication to switch to the second IAB home to the next-hop communication device (eg, IAB node 520) to instruct the next-hop communication device to switch to the second IAB home, or to the first IAB home
  • the next-hop communication device of the first IAB node may be an IAB node or a UE that is a child node of the first IAB node.
  • the next hop communication device is the IAB node 520.
  • the next hop communication device is the UE 510.
  • the first IAB node may directly send an instruction to the next-hop communication device to switch to the second IAB host.
  • the first IAB node may send the handover indication to the next hop via a Backhaul Adaptation Protocol (BAP) layer control Packet Data Unit (PDU) or a Medium Access Control (MAC) Control Element (CE) communication device.
  • BAP Backhaul Adaptation Protocol
  • PDU Packet Data Unit
  • MAC Medium Access Control
  • CE Medium Access Control
  • an indication of index information including pre-configuration information of the target cell controlled by the target IAB host may be sent by the IAB node 530 to the next-hop communication device IAB node 520 using a BAP layer control PDU or a MAC CE.
  • the first IAB node may send an instruction to switch to the second IAB host to all next-hop communication devices.
  • the first IAB node may perform a handover to the second IAB home after sending an indication to the next-hop communication device to switch to the second IAB home.
  • IAB node 530 may perform a handover to the target IAB host.
  • the next-hop communication device may also perform handover to the second IAB host based on the instruction, thereby realizing synchronous handover of the upstream and downstream devices.
  • the first IAB node may implement the handover to the target cell of the target IAB host through a random access procedure.
  • the first IAB node may perform a four-step random access procedure or a two-step random access procedure to access the target cell.
  • the random access of the first IAB node it can be determined that the handover is completed.
  • the first IAB node may perform the handover to the second IAB host in response to receiving an indication of handover completion from the next-hop communication device. For example, after IAB node 530 sends a handover indication to next-hop communication device IAB node 520, if IAB node 530 receives an indication of handover completion from IAB node 520, IAB node 530 may perform a handover to the target IAB host.
  • the IAB node 520 can trigger the handover of its child node UE 510 based on the handover instruction from the IAB node 530, and after receiving the indication that the handover of the UE 510 is complete Switch after that.
  • the IAB node 520 may forward the handover indication to its downstream node UE 510.
  • the IAB node 520 may perform a handover to the target IAB host in response to receiving the indication that the UE 510 handover is complete.
  • IAB node 530 may perform a handover to the target IAB host in response to IAB node 520 indicating that the handover is complete.
  • the operation of the IAB node 520 will be further described later with reference to FIG. 8 .
  • the first IAB node may directly perform the handover to the second IAB host without receiving an indication that the handover is complete .
  • the IAB node 530 sends the handover instruction to the next-hop communication device IAB node 520
  • the IAB node 530 can directly perform the handover to the target IAB host without waiting for the indication of the completion of the handover of the downstream node IAB node 520 and the UE 510 . In this way, the handover delay can be further reduced, and the handover efficiency can be improved.
  • the instruction sent to the next-hop communication device to switch to the second IAB host may include index information of pre-configured information of the target cell controlled by the second IAB host.
  • receiving pre-configuration information from an IAB host may be included in an IAB node or UE, which may include topology management, routing management, QoS management, and the like.
  • the pre-configuration information of different communication devices may be different, but may correspond to the same index information.
  • the index information may be associated with the identity of the target cell. In this way, when the next-hop communication device receives the handover instruction, it can determine which target cell to hand over to according to the identifier of the target cell.
  • the index information may also be associated with the first IAB node, so that which upstream node needs to be handed over can be determined according to the identifier of the first IAB node.
  • the next-hop communication device can activate the pre-configuration information corresponding to the index information accordingly, that is, make the pre-configuration information corresponding to the index information take effect, without requiring the CU of the IAB host to re-issue the configuration information, thereby Delay can be reduced.
  • the first IAB node may send a request to the first IAB host to switch to the second IAB host. Then, the first IAB host centrally controls the handover of the first IAB node and its downstream communication devices to the second IAB host. The operation of the first IAB host will be described in detail later with reference to FIG. 11 and FIG. 12 .
  • the first IAB node may receive an indication from the first IAB host that the next-hop communication device of the first IAB node has switched to the second IAB host.
  • the first IAB node may perform the handover to the second IAB host after receiving an indication from the first IAB host that the next-hop communication device has switched to the second IAB host. For example, after IAB node 530 sends a request to IAB host 550, if IAB node 530 receives an indication from IAB host 550 that the IAB node 520 handover is complete, IAB node 530 may perform a handover to the target IAB host.
  • an identity of a target cell controlled by the second IAB donor may be included in the handover request sent to the first IAB donor to notify the first IAB donor of the handover target cell.
  • the first IAB host can notify the downstream nodes of the first IAB node of the target cell for handover, so that the downstream nodes of the first IAB node can be handed over to the target IAB host corresponding to the target cell.
  • the switching conditions can be pre-configured. Therefore, IAB nodes may experience configuration conflicts.
  • the first IAB node may trigger a conditional handover at the same time as its upstream node (or device). For example, a first IAB node (eg, IAB node 530 ) receives a switch from a previous hop IAB node (eg, IAB node 540 ) to a different third IAB host while determining that the conditions for switching to the second IAB host have been met instructions.
  • the IAB node 530 may also receive from the upstream IAB node 540 a handover to another IAB host (not shown) instructions.
  • the first IAB node may also send a request for switching to the second IAB host to the first IAB host, and the first IAB host may make a handover decision and conflict resolution.
  • the IAB node 530 may send a handover request to the IAB host 550 to which it belongs when a handover condition is triggered.
  • the handover request may include the identity of the target cell.
  • the IAB node 540 may also send a handover request carrying the identity of the target cell to the IAB host 550 . In this way, which cell to switch to and which set of configurations to adopt can be decided by the first IAB host.
  • the first IAB node may have handover priority.
  • the first IAB node and its downstream nodes may switch to the second IAB host first, and then switch to the previous IAB node.
  • the IAB node 530 and its downstream nodes may first switch to the IAB host 560 determined by the IAB node 530 itself triggering the switching. Then, the upstream node IAB node 540 performs handover again. In this case, it may happen that the MT and DU parts of the IAB node 540 are managed by different IAB hosts, respectively.
  • the upstream IAB node may have handover priority.
  • the first IAB node and its downstream nodes follow the handover decision of the previous hop IAB node, and firstly switch to a third IAB host that is different from the second IAB host. Then, the first IAB node determines whether to continue to perform the handover according to the handover condition.
  • the IAB node 540 and its downstream nodes may first switch to the third IAB host determined by the IAB node 540 triggering the switching by itself.
  • the IAB node 530 may determine whether the handover condition is satisfied based on the communication quality of the cell controlled by the handed-over third IAB donor and the neighboring cell, so as to determine whether the handover is still to be performed. The embodiment of this aspect will be further described later with reference to FIG. 8 .
  • FIG. 8 illustrates a flowchart 800 of a handover method implemented at a communication device downstream of an IAB node that initiates a cross-IAB home handover in accordance with certain embodiments of the present disclosure.
  • the method 800 may be performed by the IAB nodes 520, 530 or 540 in FIG. 5 .
  • the method 800 will be described below with reference to FIG. 5 in conjunction with a scenario where the IAB node 530 initiates a handover from the IAB host 550 to the IAB host 560 .
  • the method 800 may be performed by the IAB node 520 .
  • a second IAB node receives a handover from a previous hop IAB node (eg, IAB node 530 or IAB node 520) from the first IAB host to the second IAB host (IAB Host 560).
  • the handover to the second IAB host is triggered by the first IAB node (eg, IAB node 530 ) located upstream of the second IAB node based on the condition that the handover to the second IAB host has been met. Accordingly, the handover instruction is generated by the first IAB node or the first IAB host (IAB host 550).
  • the last hop IAB node may or may not be the same as the first IAB node.
  • the IAB node 530 when the second IAB node is implemented by the IAB node 520 , the previous hop IAB node and the first IAB node are the same node, and both are the IAB node 530 .
  • the first IAB node is implemented by the IAB node 540 and the second IAB node is implemented by the IAB node 520
  • its previous hop IAB node is the IAB node 530, which is different from the IAB node 540 which is the first IAB node.
  • the second IAB node forwards to the next hop communication device (eg, UE 510) an indication to switch to the second IAB host.
  • the next hop communication device eg, UE 510
  • the second IAB node may first determine whether there is a next-hop device. If the second IAB node has a next-hop communication device, the second IAB node may forward an instruction to switch to the second IAB home to the next-hop communication device of the second IAB node before performing the handover to the second IAB home. The second IAB node may perform a handover to the second IAB host in response to receiving an indication of handover completion from its next-hop communication device.
  • the second IAB node 520 may send a handover to the next-hop communication device UE 510 before handing over to the target IAB host 560 Instructions to the same target IAB host 560.
  • the second IAB node 520 may perform a handover to the target IAB host 560 in response to receiving an indication from the UE 510 that the handover is complete.
  • the second IAB node and its downstream nodes can be jointly handed over to the second IAB host as the handover target.
  • the second IAB node may directly perform the handover to the second IAB host without waiting for a handover complete indication from the downstream node.
  • the second IAB node may directly perform a handover to the second IAB host.
  • the second IAB node may send an indication that the handover is completed to the previous-hop IAB node.
  • the indication of handover completion may be an RRC message relayed to the IAB host by the upstream node.
  • the upstream node can determine that the downstream node has completed the handover according to the message type. For example, after the UE 510 is handed over to the target IAB host 560, an indication of handover completion may be sent to the IAB node 520 of the previous hop. After switching to the target IAB 560, the IAB node 520 may send an indication that the switching is completed to the IAB node 530 of the previous hop.
  • the second IAB node may receive from the previous hop IAB node an indication generated by the first IAB host to switch from the first IAB host to the second IAB host.
  • the first IAB host may generate and send the indication to the second IAB node in response to a handover request from the second IAB node. For example, if the second IAB node determines that the conditions for switching to a different fourth IAB host have been met at the same time as the second IAB node receives an instruction to switch to the second IAB host from the previous hop IAB, it may send a switch to the fourth IAB host to the first IAB host.
  • the handover request may include a handover target cell.
  • a handover instruction may be sent to the second IAB node. It should be understood that the handover instruction generated by the first IAB host and sent to the second IAB node can be forwarded by the upstream node of the second IAB node to the second IAB node step by step, so the second IAB node can hop from the previous IAB node.
  • a handover indication generated by the first IAB host is received.
  • the upstream IAB node may have handover priority when the handover decision of the downstream second IAB node collides with the upstream first IAB node.
  • the downstream second IAB node follows the handover decision of the first IAB node and firstly switches to the second IAB host. Then, the second IAB node determines whether to continue the handover according to the handover condition.
  • the downstream second IAB node may have handover priority. For example, the second IAB node may switch to the fourth IAB host first, and then switch to the previous IAB node.
  • the handover indication sent by the first IAB host to the second IAB node may be triggered by a handover request from an upstream node of the second IAB node.
  • the second IAB node is implemented by the IAB node 520
  • at its upstream IAB node 530 sends the IAB host 550 acting as the first IAB host to the IAB host 560 acting as the second IAB host based on the handover condition decision Following the handover request
  • IAB node 520 may receive an indication from IAB host 550 in response to IAB node 530's handover request.
  • the instruction to switch to the second IAB host may include index information of the pre-configured information received by the second IAB node from the first IAB host.
  • the index information may be associated with the target cell.
  • the IAB node or UE may receive pre-configuration information from the IAB host, and the pre-configuration information may include topology management, routing management, QoS management, and the like.
  • the configuration information of different communication devices may be different, but may correspond to the same index information.
  • the second IAB node can validate the pre-configuration information associated with the index information to perform handover using the pre-configuration information. For example, which target cell to be handed over can be determined according to the identity of the target cell corresponding to the index information.
  • the second IAB node can also determine which upstream node needs to be handed over.
  • the communication device may perform the handover by validating the corresponding pre-configuration. In this way, the communication device can activate the corresponding configuration information accordingly without requiring the CU of the IAB host to re-issue the configuration information, thereby saving system overhead and reducing time delay.
  • FIG. 9 illustrates an example handover process 900 when a handover from an IAB host 550 to 560 is initiated by an IAB node 530 in an environment 500 in accordance with certain embodiments of the present disclosure.
  • the MT 532 of the IAB node 530 determines (902) that a switch from the IAB host 550 (as the first IAB host) to the IAB host 560 (as the second IAB host) is reached host) conditions.
  • the MT 532 of the IAB node 530 instructs the DU 531 to send (904) an indication to the next hop IAB node 520 to switch to the IAB host 560.
  • the indication can be delivered via BAP layer control PDU or MAC CE.
  • the instruction may carry configuration information or corresponding index information that the IAB node 530 needs to activate.
  • the configuration information may be configuration information at DU2b under the control of the CU 562 of the target IAB host 560, such as topology management, routing management and QoS management information.
  • the IAB node 530 may have correspondingly different configurations. Different configurations can correspond to different indexes.
  • the IAB node 530 may select a corresponding configuration according to the target cell.
  • the configuration information may be previously sent to the IAB node 530 by the CU 552 of the source IAB host 550.
  • the CU 55 of the IAB host 550 may also take the IAB node 530 as the head node, and send configuration information to the downstream nodes of the IAB node 530 (including the IAB node 520 and the UE 510) in advance for different target cells that it can switch to.
  • the configuration information of different nodes may be different, but may correspond to the same index information.
  • the index information can be distinguished by the ID of the IAB node and the ID of the target cell. In this way, when the downstream node receives the handover instruction, it can determine which upstream node needs to be handed over and which is the target cell. In this way, the corresponding configuration information can be used without requiring the CU 552 of the IAB host 550 to re-issue the configuration information, thereby reducing the time delay.
  • IAB node 520 After receiving the indication sent by IAB node 530, IAB node 520 determines (906) whether it has a next-hop node. In this example, there is also UE 510 downstream of IAB node 520. Accordingly, the IAB node 520 forwards (908) an indication to the downstream UE 510 to switch to the IAB host 560. Since UE 510 has no downstream nodes, UE 510 performs handover after receiving the handover indication (910). After the UE 510 completes the handover, it may send (912) a handover completion indication to the IAB node 520 of the previous hop. IAB node 520 may determine (914) whether handover complete indications have been received from all next-hop nodes, including UE 510.
  • IAB node 520 may hand over ( 918 ) to destination IAB host 560 . Afterwards, the IAB node 520 may send (920) a handover complete indication to the IAB node 530. After IAB node 530 determines ( 922 ) that handover complete indications from all next-hop nodes (including IAB node 520 ) have been received, IAB node 530 may switch ( 924 ) to destination IAB host 560 .
  • FIG. 10 illustrates another example handover process 1000 when a handover from an IAB host 550 to 560 is initiated by an IAB node 530 in an environment 500 in accordance with certain embodiments of the present disclosure.
  • the difference from the first process 900 shown in FIG. 9 is that after the upstream node (eg, IAB node 530 ) sends the instruction to switch to the target IAB host 560 to the downstream node (eg, IAB node 520 ), the upstream node can directly The handover is performed without waiting to receive an indication of the completion of the handover from the downstream node.
  • the upstream node eg, IAB node 530
  • the upstream node can directly The handover is performed without waiting to receive an indication of the completion of the handover from the downstream node.
  • MT 532 of IAB node 530 determines (1002) that the conditions for switching from IAB host 550 to IAB host 560 are reached.
  • the MT 532 of the IAB node 530 instructs the DU 531 to send (1004) an instruction to the next hop IAB node 520 to switch to the IAB host 560.
  • the indication may include configuration information or corresponding index information as described with reference to FIG. 9 .
  • the IAB node 530 directly activates the corresponding configuration to switch (1006) to the IAB host 560 after sending the handover indication to the next-hop IAB node 520.
  • the MT 532 of the IAB node 530 switches from the DU of the upstream node controlled by the IAB host 550 to the DU of the upstream node controlled by the IAB host 560.
  • IAB node 520 may determine (1008) whether it has a next-hop device. Since the IAB node 520 has the downstream device UE 510, the IAB node 520 forwards (1010) the indication to switch to the IAB host 560 to the downstream UE 510. After sending an indication to the downstream UE 510, the IAB node 520 may activate the corresponding configuration to switch (1012) to the IAB host 560.
  • the MT 522 of the IABIAB node 520 switches from the DU of the upstream node controlled by the IAB host 550 to the DU of the upstream node controlled by the IAB host 560.
  • UE 510 may switch (1014) to IAB host 560 after receiving an indication from IAB node 520.
  • the handover of the first IAB node and its downstream communication devices to the second IAB host which is the destination IAB host can be centrally controlled by the first IAB host which is the source IAB host during the handover process. Specific embodiments of this aspect are described below with reference to FIGS. 11 and 12 .
  • Figure 11 shows a flow diagram of a handover method 1100 implemented at an IAB host in accordance with certain embodiments of the present disclosure.
  • Method 1100 may be performed by IAB host 550 or IAB host 560 in FIG. 5 .
  • the method 1100 will be described below with reference to FIG. 5 in conjunction with a scenario where the IAB node 530 initiates a handover from the IAB host 550 to the IAB host 560 .
  • a first IAB host receives a request from a first IAB node (eg, IAB node 530) to switch to a second IAB host (eg, IAB host 560).
  • the handover to the second IAB host is triggered by the first IAB node based on that the conditions for handover to the second IAB host have been met.
  • the switching conditions can be pre-configured by the network.
  • the identity of the target cell controlled by the second IAB host may be included in the handover request to the second IAB host.
  • the first IAB host sends an indication to the communication device downstream of the first IAB node to switch to the second IAB host in bottom-up order.
  • the first IAB host may first send an indication to switch to the second IAB host to end communication devices downstream of the first IAB node.
  • the end communication device may be a UE or an IAB node without downstream nodes.
  • the first IAB home may send an indication to switch to the second IAB home to the last hop communication device of the end communication device located downstream of the first IAB node.
  • the terminal device is the UE 510
  • the first IAB host 550 may first send a handover instruction to the UE 510.
  • the first IAB host 550 may send a handover instruction to the previous hop node of the UE 510, that is, the IAB node 520.
  • the instruction to switch to the second IAB host may include index information of pre-configured information of the target cell controlled by the second IAB host.
  • the index information is associated with the target cell.
  • the node can determine the configuration to activate based on the index information.
  • the pre-configuration information may be sent by the first IAB host to the communication device downstream of the first IAB node.
  • the first IAB host may send pre-configuration information to the communication device downstream of the first IAB node. In this way, the communication devices downstream of the first IAB node are pre-configured, so that based on the received index information, it is possible to determine which set of configurations is valid for performing handover to the target cell controlled by the second IAB host.
  • configuration information for switching to a target cell controlled by the second IAB donor may be included in the handover instruction to the second IAB donor.
  • the communication device downstream of the first IAB node can be able to use the received configuration information to perform handover to the target cell controlled by the second IAB host without being preconfigured.
  • the first IAB host sends to the first IAB node that the first IAB node's next-hop communication device has switched to the second IAB Host's instructions. For example, after all devices (including IAB node 520 and UE 510) downstream of the first IAB node (eg, IAB node 530) have completed the handover, the first IAB host determines that the next-hop communication device of the first IAB node has been handed over to The second IAB host may then send the above indication to the first IAB node.
  • the first IAB host in addition to receiving handover requests from the first IAB node, the first IAB host (eg, IAB host 550) may also receive handover requests from one or more other IAB nodes. For example, during a CHO process, IAB node 530 and IAB node 540 may trigger a handover condition at the same time. If the destination IAB hosts of the multiple IAB nodes are different, the first IAB host may make a handover decision to determine which destination IAB host and/or which destination cell to switch to. In this case, the handover instruction sent by the first IAB host to each IAB node may include the identity of the cell to be handed over, configuration information or corresponding index information. In this way, each IAB node can switch synchronously, avoiding conflict.
  • FIG. 12 illustrates an example handover process 1200 in an environment 500 where an IAB host 550 centrally controls an IAB node 530-initiated switch from an IAB host 550 to 560 in accordance with certain embodiments of the present disclosure.
  • the MT 532 of the IAB node 530 determines (1202) that the conditions for switching from the IAB host 550 to the IAB host 560 are reached.
  • the handover to the IAB host 560 is triggered by the IAB node 530 based on that the conditions for handover to the IAB host 560 have been met.
  • the IAB node 530 sends (1204) a request to the CU 552 of the IAB host 550 to switch from the IAB host 550 to the IAB host 560.
  • the request may include the identity of the target cell controlled by the IAB host 560 .
  • the IAB host 550 sends an instruction to switch to the IAB host 560 to the communication devices downstream of the IAB node 530 (including the UE 510 and the IAB node 520) in a bottom-up order.
  • the indication may include index information of the configuration to be activated for handover to the target cell controlled by the IAB host 560 .
  • the index information is associated with the IAB node 530 and the target cell.
  • the indication may also directly include configuration information corresponding to a downstream communication device (eg, UE 510 or IAB node 520).
  • the IAB host 550 may first send (1210) an indication to switch to the IAB host 560 to the end communication device UE 510 downstream of the IAB node 530.
  • the CU 552 of the IAB host 550 may send a handover indication to the UE 510.
  • the handover indication may have the following possible situations.
  • the instruction may include an index corresponding to the configuration information. The index can be associated with the IAB head node (ie, IAB node 530) ID and the target cell ID, so the receiving device can activate the relevant configuration according to the index.
  • the instruction may include configuration information corresponding to the receiving device.
  • the receiving device can directly use the configuration information issued by the CU 552 of the IAB host 550 to activate the corresponding configuration.
  • the UE 510 may activate the corresponding configuration to handover from the IAB host 550 to the IAB host 560 based on the indication (1208).
  • the UE 510 may send (1210) an indication that the handover is complete to the IAB host 550 after the handover is complete.
  • the IAB donor 550 may send (1212) a handover indication to the previous hop node IAB node 520 of the UE 510 after receiving the indication that the handover of the UE 510 is complete.
  • the IAB node 520 may switch (1214) to the IAB host 560 based on the indication.
  • the IAB node 520 may send (1216) an indication that the handover is complete to the IAB host 550 after the handover is complete. Similarly, the IAB host 550 may in turn send handover indications to communication devices downstream of the IAB node 530 . Based on the IAB host 550 determining (1218) that all downstream nodes of the IAB node 530 have completed the handover, the IAB host 550 may send (1220) an indication to the IAB node 530 that the downstream node handover is complete. The CU 552 of the IAB host 550 may instruct the MT 532 of the IAB node 530 to switch from the CU 552 of the IAB host 550 to the CU 562 of the IAB host 560. The IAB node 530 may switch (1222) to the IAB host 560 based on the indication that the downstream node handover is complete, thereby completing the overall handover process.
  • the IAB node when the IAB node triggers CHO, it can timely instruct its downstream nodes to perform handover from bottom to top, thereby ensuring service continuity of the UE.
  • Embodiments of the present disclosure also provide corresponding apparatuses for implementing the above-mentioned methods or processes.
  • FIG. 13 shows a schematic structural block diagram of an apparatus 1300 at an IAB node that initiates a cross-IAB home handover according to some embodiments of the present disclosure.
  • the apparatus 1300 includes a condition determination module 1305, which is configured to determine through the first IAB node that the condition for switching from the first IAB host to the second IAB host has been satisfied; the first sending module 1310 is configured to pass the first IAB node.
  • An IAB node sends an instruction to switch to the second IAB host to the next-hop communication device to instruct the next-hop communication device to switch to the second IAB host, or sends a request for switching to the second IAB host to the first IAB host.
  • the apparatus 1300 when the first sending module 1310 is configured to send an instruction to switch to the second IAB host through the first IAB node to the next-hop communication device, the apparatus 1300 further includes: a first switching module , the first handover module is configured to perform handover to the second IAB host through the first IAB node in response to the first IAB node receiving an indication of handover completion from the next-hop communication device.
  • index information with the pre-configuration information of the target cell controlled by the second IAB donor is included in the handover instruction to the second IAB donor, so that the next-hop communication device validates the pre-configuration information for handover to the target cell.
  • the indication to switch to the second IAB host is sent by the first IAB node to the next-hop communication device through the backhaul adaptation protocol BAP layer control packet data unit PDU or medium access control MAC control element CE.
  • the apparatus 1300 when the first sending module 1310 is configured to send a request to the first IAB host to switch to the second IAB host through the first IAB node, the apparatus 1300 further includes an instruction receiving module and a second IAB host. Switch modules.
  • the indication receiving module is configured to receive, via the first IAB node, an indication from the first IAB host that the next-hop communication device of the first IAB node has switched to the second IAB host.
  • the second handover module is configured to perform a handover to the second IAB host by the first IAB node.
  • FIG. 14 shows a schematic structural block diagram of an apparatus 1400 at a downstream communication device of an IAB node that initiates a cross-IAB home handover according to some embodiments of the present disclosure.
  • the apparatus 1400 includes a first receiving module 1405 and a forwarding module 1410 .
  • the first receiving module 1405 is configured to receive an indication of switching from the first IAB host to the second IAB host from the previous hop IAB node through the second IAB node.
  • the forwarding module 1410 is configured to forward the instruction of switching from the first IAB host to the second IAB host to the downstream communication device through the second IAB node, so as to instruct the downstream communication device to switch from the first IAB host to the second IAB host.
  • the apparatus 1400 further includes a first switching module.
  • the first handover module is configured to perform the handover to the second IAB host by the second IAB node in response to the second IAB node receiving an indication of handover completion from the next-hop communication device.
  • the instruction to switch from the first IAB host to the second IAB host includes index information of the pre-configuration information received by the second IAB node from the first IAB host, the index information being the same as that controlled by the second IAB host associated with the target cell.
  • the first handover module includes a configuration validation module, and the configuration validation module is configured to validate the pre-configuration information through the second IAB node to handover to the target cell.
  • FIG. 15 shows a schematic structural block diagram of an apparatus 1500 at an IAB host according to some embodiments of the present disclosure.
  • the apparatus 1500 includes a request receiving module 1505 , a first instruction sending module 1510 and a second instruction sending module 1515 .
  • the request receiving module 1505 is configured to receive, via the first IAB host, a request from the first IAB node to switch to the second IAB host, wherein the switch to the second IAB host is performed by the first IAB node based on a condition for switching to the second IAB host triggered by being satisfied.
  • the first instruction sending module 1510 is configured to send an instruction to switch to the second IAB host to the communication device downstream of the first IAB node in a bottom-up order through the first IAB host.
  • the second indication sending module 1515 is configured to send the next-hop communication device of the first IAB node to the first IAB node through the first IAB host after the next-hop communication device of the first IAB node has been switched to the second IAB host Indication that a switch to the second IAB host has been made.
  • the first indication sending module 1510 includes a first handover indication sending module and a second handover indication sending module.
  • the first switching instruction sending module is configured to send an instruction to switch to the second IAB host to the terminal communication device downstream of the first IAB node through the first IAB host.
  • the second handover indication sending module is configured to, after the end communication device has been handed over to the second IAB host, send the handover to the second IAB to the previous hop communication device of the end communication device located downstream of the first IAB node through the first IAB host Host's instructions.
  • the instruction to switch to the second IAB host includes index information of pre-configured information received from the first IAB host by the communication device downstream of the first IAB node, the index information being the same as the one controlled by the second IAB host. associated with the target cell.
  • the first instruction sending module 1510 includes a configuration validating module, which is configured to validate the pre-configuration information through a communication device downstream of the first IAB node to switch to the target cell.
  • the modules included in the apparatuses 1300, 1400, and 1500 may be implemented in various ways, including software, hardware, firmware, or any combination thereof.
  • one or more modules may be implemented using software and/or firmware, such as machine-executable instructions stored on a storage medium.
  • some or all of the modules in apparatuses 1300, 1400, and 1500 may be implemented, at least in part, by one or more hardware logic components.
  • exemplary types of hardware logic components include field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standards (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLD), etc.
  • FIG. 16 shows a block diagram of a device 1600 in which certain embodiments of the present disclosure may be implemented.
  • Apparatus 1600 can be used to implement IAB nodes 520, 530, 540, UE 510, or IAB hosts 550 or 560 shown in Figure 5, for example.
  • the device 1600 includes a processor 1610 that controls the operation and functionality of the device 1600 .
  • processor 1610 may perform various operations by virtue of instructions 1630 stored in memory 1620 coupled thereto.
  • Memory 1620 may be of any suitable type suitable for use in the local technical environment, and may be implemented using any suitable data storage technology, including but not limited to semiconductor-based storage devices, magnetic storage devices and systems, optical storage devices and systems. Although only one memory unit is shown in FIG. 16 , there may be multiple physically distinct memory units in device 1600 .
  • Processor 1610 may be of any suitable type suitable for use in the local technical environment, and may include, but is not limited to, general purpose computers, special purpose computers, microcontrollers, digital signal controllers (DSPs), and controller-based multi-core controller architectures. one or more.
  • Device 1600 may also include multiple processors 1610 .
  • the processor 1610 is coupled with the communication unit 1640 .
  • the communication unit 1640 may enable reception and transmission of information through radio signals or by means of optical fibers, cables, and/or other components.
  • the processor 1610 may implement the operations and actions at the first IAB node described above with reference to FIGS. 5 to 12 by executing instructions.
  • the processor 1610 may implement the operations and actions at the second IAB node described above with reference to FIGS. 5 to 12 by executing instructions.
  • the processor 1610 may implement the operations and actions at the source IAB host described above with reference to FIGS. 5-12 by executing instructions. All of the features described above with reference to FIGS. 5-12 are applicable to the device 1600 and will not be repeated here.
  • the various example embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic, or any combination thereof. Certain aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor or other computing device. While aspects of the example embodiments of the present disclosure are illustrated or described as block diagrams, flowcharts, or using some other graphical representation, it will be understood that the blocks, apparatus, systems, techniques, or methods described herein may be taken as non-limiting Examples of are implemented in hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controllers or other computing devices, or some combination thereof.
  • example embodiments of the present disclosure may be described in the context of machine- or computer-executable instructions, such as included in program modules executed in a device on a target's real or virtual processor.
  • program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data structures.
  • the functionality of the program modules may be combined or divided among the described program modules.
  • Machine-executable instructions for program modules may be executed within local or distributed devices. In a distributed facility, program modules may be located in both local and remote storage media.
  • Computer program code for implementing the methods of the present disclosure may be written in one or more programming languages. Such computer program code may be provided to a processor of a general purpose computer, special purpose computer or other programmable data processing apparatus such that the program code, when executed by the computer or other programmable data processing apparatus, causes the flowchart and/or block diagrams The functions/operations specified in are implemented.
  • the program code may execute entirely on the computer, partly on the computer, as a stand-alone software package, partly on the computer and partly on a remote computer or entirely on the remote computer or server.
  • a machine-readable medium or computer-readable medium may be any tangible medium that contains or stores a program for or in connection with an instruction execution system, apparatus, or device.
  • the machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium.
  • Machine-readable media may include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or devices, or any suitable combination thereof. More detailed examples of machine-readable storage media include electrical connections with one or more wires, portable computer disks, hard disks, random access memory (RAM), read only memory (ROM), erasable programmable read only Memory (EPROM or flash memory), optical storage devices, magnetic storage devices, or any suitable combination thereof.

Landscapes

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

Abstract

提供接入回传一体化(IAB)网络中的切换的方法、设备和介质。在示例方法中，第一IAB节点确定从第一IAB宿主切换到第二IAB宿主的条件已经满足(705)。第一IAB节点向下一跳通信设备发送切换到第二IAB宿主的指示以指示下一跳通信设备切换到第二IAB宿主，或者向第一IAB宿主发送对于切换到第二IAB宿主的请求(710)。由此，下游IAB节点或用户设备可以及时地与上游节点共同切换到目标IAB宿主，从而保证业务的连续性。

Description

接入回传一体化网络中的切换的方法、设备和介质 技术领域
本公开涉及无线局域网领域，更具体地，涉及接入回传一体化网络中的切换的方法、装置和介质。
背景技术
相较于第四代移动通信系统，第五代(the fifth generation，5G)移动通信系统对于网络各项性能指标提出了更严苛的要求。例如，要求容量提升1000倍，具有更广的覆盖需求，并其要求超高可靠性和超低时延等。考虑到高频载波频率资源丰富，在热点区域，为满足5G超高容量需求，利用高频小站组网愈发流行。然而，高频载波传播特性较差，受遮挡衰减严重，覆盖范围不广，故而需要大量密集部署小站。相应地，为这些大量密集部署的高频小站提供光纤回传的代价很高，施工难度大，因此需要经济便捷的回传方案。另外，从广覆盖需求的角度出发，当在一些偏远地区提供网络覆盖时，光纤的部署难度大，成本高，因此也需要设计灵活便利的接入和回传方案。
接入回传一体化(Integrated access and backhaul，IAB)技术为解决上述两个问题提供了思路。随着5G的发展，IAB技术得到了广泛的应用。在IAB网络中，接入链路(Access Link)和回传链路(Backhaul Link)皆采用无线传输方案，因此可以减少用于大量密集小站的光纤的部署。
发明内容
本公开提供了一种在回传接入一体化(IAB)网络中的切换方案。
在本公开的第一方面，提供了一种切换方法。在该方法中，第一IAB节点确定从第一IAB宿主切换到第二IAB宿主的条件已经满足。继而，第一IAB节点向下一跳通信设备发送切换到第二IAB宿主的指示以指示下一跳通信设备切换到第二IAB宿主，或者向第一IAB宿主发送对于切换到第二IAB宿主的请求。通过由满足切换条件的IAB节点向下一跳节点发送指示以指示下一跳通信设备进行切换，可以使下游IAB节点或用户设备及时地与上游节点共同切换到目标IAB宿主，从而保证业务的连续性。
在某些实现方式中，在第一IAB节点向下一跳通信设备发送切换到第二IAB宿主的指示的情况下，响应于第一IAB节点从下一跳通信设备接收到切换完成的指示，第一IAB节点执行到第二IAB宿主的切换。以此方式，可以进一步提高切换成功的概率，提高切换操作的效率。
在某些实现方式中，在切换到第二IAB宿主的指示中包括与由第二IAB宿主控制的目标小区的预配置信息的索引信息，以使得下一跳通信设备使预配置信息生效以切换到目标小区。通过传输索引信息来使相应的预配置信息生效，不需要由IAB宿主或者第一IAB节点向下一跳通信设备发送配置信息，从而可以显著节省系统开销，并且大大降低切换时延。
在某些实现方式中，切换到第二IAB宿主的指示由第一IAB节点通过回传适配协议(BAP)层控制分组数据单元(PDU)或媒体接入控制(MAC)控制元素(CE)发送给下一跳通信设备。通过复用BAP PDU或MAC CE来由第一IAB节点向下一跳通信设备传输切换指示，不 必引入新的信令或消息，有助于实现后向兼容。
在某些实现方式中，在第一IAB节点向第一IAB宿主发送切换到第二IAB宿主的请求的情况下，第一IAB节点在从第一IAB宿主接收第一IAB节点的下一跳通信设备已经切换到第二IAB宿主的指示之后，执行到第二IAB宿主的切换。由此，可以进一步提高切换成功的概率，提高切换操作的效率。
在本公开的第二方面，提供了一种切换方法。在该方法中，第二IAB节点从上一跳IAB节点接收从第一IAB宿主切换到第二IAB宿主的指示。继而，第二IAB节点向下游通信设备转发从第一IAB宿主切换到第二IAB宿主的指示，以指示下游通信设备从第一IAB宿主切换到第二IAB宿主。
在某些实现方式中，响应于第二IAB节点从下一跳通信设备接收到切换完成的指示，第二IAB节点执行到第二IAB宿主的切换。
在某些实现方式中，在从第一IAB宿主切换到第二IAB宿主的指示中包括第二IAB节点从第一IAB宿主接收的预配置信息的索引信息，索引信息与由第二IAB宿主控制的目标小区相关联。而且，第二IAB节点使预配置信息生效以切换到目标小区。
在本公开的第三方面，提供了一种切换设备。该设备包括条件确定模块和第一发送模块。条件确定模块被配置为通过第一IAB节点确定从第一IAB宿主切换到第二IAB宿主的条件已经满足。第一发送模块被配置为通过第一IAB节点向下一跳通信设备发送切换到第二IAB宿主的指示以指示下一跳通信设备切换到第二IAB宿主，或者向第一IAB宿主发送对于切换到第二IAB宿主的请求。
在某些实现方式中，在第一发送模块被配置为通过第一IAB节点向下一跳通信设备发送切换到第二IAB宿主的指示的情况下，该设备还包括第一切换模块，第一切换模块被配置为响应于第一IAB节点从下一跳通信设备接收到切换完成的指示，通过第一IAB节点执行到第二IAB宿主的切换。
在某些实现方式中，在切换到第二IAB宿主的指示中包括与由第二IAB宿主控制的目标小区的预配置信息的索引信息，以使得下一跳通信设备使预配置信息生效以切换到目标小区。
在某些实现方式中，切换到第二IAB宿主的指示由第一IAB节点通过回传适配协议BAP层控制分组数据单元PDU或媒体接入控制MAC控制元素CE发送给下一跳通信设备。
在某些实现方式中，在第一发送模块被配置为通过第一IAB节点向第一IAB宿主发送切换到第二IAB宿主的请求的情况下，该设备还包括指示接收模块和第二切换模块。指示接收模块被配置为通过第一IAB节点从第一IAB宿主接收第一IAB节点的下一跳通信设备已经切换到第二IAB宿主的指示。第二切换模块被配置为通过第一IAB节点执行到第二IAB宿主的切换。
在本公开的第四方面，提供了一种切换装置。该装置包括第一接收模块和转发模块。第一接收模块被配置为通过第二IAB节点从上一跳IAB节点接收从第一IAB宿主切换到第二IAB宿主的指示。转发模块被配置为通过第二IAB节点向下游通信设备转发从第一IAB宿主切换到第二IAB宿主的指示，以指示下游通信设备从第一IAB宿主切换到第二IAB宿主。
在某些实现方式中，该装置还包括第一切换模块。第一切换模块被配置为响应于第二IAB节点从下一跳通信设备接收到切换完成的指示，通过第二IAB节点执行到第二IAB宿主的切换。
在某些实现方式中，在从第一IAB宿主切换到第二IAB宿主的指示中包括第二IAB节点从第一IAB宿主接收的预配置信息的索引信息，索引信息与由第二IAB宿主控制的目标小区相关联。第一切换模块包括配置生效模块，配置生效模块被配置为通过第二IAB节点使预配置信息生效以切换到目标小区。
在本公开的第五方面，提供了一种IAB系统。该IAB系统包括第一IAB节点和第二IAB节点。第一IAB节点被配置为执行根据本公开的第一方面的方法。第二IAB节点被配置为执行根据本公开的第二方面的方法。
在本公开的第六方面，提供了一种通信设备。该设备包括处理器，该处理器与存储指令的存储器耦合。该指令在被处理器执行时使根据本公开的第一或第二方面的方法被执行。
在本公开的第七方面，提供了一种计算机可读存储介质，其上存储有程序，至少部分程序在由设备中的处理器执行时，使设备执行根据本公开的第一或第二方面的方法。
在本公开的第八方面，提供了一种芯片，包括处理电路，被配置为执行根据本公开的第一或第二方面的方法。
在本公开的第九方面，提供了一种计算机程序产品，存储计算机程序，至少部分程序在由设备中的处理器执行时，使设备执行根据本公开的第一或第二方面的方法。
应当理解，发明内容部分中所描述的内容并非旨在限定本公开的关键或重要特征，亦非用于限制本公开的范围。本公开的其它特征将通过以下的描述变得容易理解。
附图说明
结合附图并参考以下详细说明，本公开各实施例的上述和其他特征、优点及方面将变得更加明显。在附图中，相同或相似的附图标记表示相同或相似的元素，其中：
图1示出了利用IAB网络的无线中继的示例场景；
图2示出了在IAB网络中按照自上而下的顺序切换IAB宿主的示例过程；
图3示出了在IAB网络中按照自下而上的顺序切换IAB宿主的示例过程；
图4示出了在IAB网络中从中间IAB节点发起的自下而上切换IAB宿主的另一示例过程；
图5示出了本公开的实施例可以在其中实施的示例环境；
图6a示出了根据本公开的某些实施例的IAB网络的控制面协议栈的示例架构；
图6b示出了根据本公开的某些实施例的IAB网络的用户面协议栈的示例架构；
图7示出了根据本公开的某些实施例的在发起跨IAB宿主切换的IAB节点处实施的切换方法的流程图；
图8示出了根据本公开的某些实施例的在发起跨IAB宿主切换的IAB节点的下游通信设备处实施的切换方法的流程图；
图9示出了根据本公开的某些实施例在图5所示的环境中执行的示例切换过程；
图10示出了根据本公开的某些实施例在图5所示的环境中执行的示例切换过程；
图11示出了根据本公开的某些实施例的在IAB宿主处实施的切换方法的流程图；
图12示出了根据本公开的某些实施例在图5所示的环境中由IAB宿主进行集中控制的示例切换过程；
图13示出了根据本公开的某些实施例的在发起跨IAB宿主切换的IAB节点处的装置的 示意性结构框图；
图14示出了根据本公开的某些实施例的在发起跨IAB宿主切换的IAB节点的下游通信设备处的装置的示意性结构框图；
图15示出了根据本公开的某些实施例的在IAB宿主处的装置的示意性结构框图；
图16示出了其中可以实施本公开的某些实施例的设备的框图。
具体实施方式
下面将参照附图更详细地描述本公开的实施例。虽然附图中示出了本公开的某些实施例，然而应当理解的是，本公开可以通过各种形式来实现，而且不应该被解释为限于这里阐述的实施例，相反提供这些实施例是为了更加透彻和完整地理解本公开。应当理解的是，本公开的附图及实施例仅用于示例性作用，并非用于限制本公开的保护范围。
在此使用的术语“包括”及其变形是开放性包括，即“包括但不限于”。术语“基于”是“至少部分地基于”。术语“一个实施例”表示“至少一个实施例”；术语“另一实施例”表示“至少一个另外的实施例”。其他术语的相关定义将在下文描述中给出。
应理解，尽管本文可以使用术语“第一”和“第二”等来描述各种元件，但这些元件不应受到这些术语的限制。这些术语仅用于区分一个元件和另一个元件。如本文所用，术语“和/或”包括一个或多个所列术语的任何和所有组合。
在IAB网络中，IAB节点(IAB node)作为中继节点RN(Relay Node)，可以为用户设备(User Equipment，UE)提供无线接入服务。UE的业务数据由IAB节点通过无线回传链路连接到IAB宿主(IAB donor)传输。IAB宿主也可称为宿主节点(donor node)或宿主基站，例如宿主下一代基站(DgNB)或宿主演进基站(DeNB)。在IAB网络中，在UE和IAB宿主之间存在一条或多条传输路径，并且每条传输路径可以包含一个或多个IAB节点。每个IAB节点需要维护面向父节点的无线回传链路，还需要维护和子节点的无线链路。
图1示出了利用IAB网络的无线中继的示例场景100。
在图1所示的场景100中，UE 101-1和UE 101-2可以通过无线接入链路连接到IAB节点102-1、102-2、102-3、102-4和102-5，从而通过无线回传链路连接到IAB宿主103。经由IAB宿主103，IAB节点102-1、102-2、102-3、102-4和102-5可以连接到核心网，例如连接到5G核心网(5GC)(图1中未示出)。
如图1所示，在IAB网络中，在UE 101-1和UE 101-2与IAB宿主103之间都存在多条传输路径，并且每条传输路径可以包含IAB节点102-1、102-2、102-3、102-4和102-5中的多个IAB节点。对于IAB节点102-1，其子节点是UE 101-1，因此该IAB节点102-1和子节点(即，UE 101-1)之间是无线接入链路。对于IAB节点102-2，其子节点是其他IAB节点102-1或102-5，因此该IAB节点102-2和子节点(即，IAB节点102-1或102-5)之间是无线回传链路。
作为示例，在路径“UE 101-2→IAB节点102-5→IAB节点102-4→IAB节点102-3→IAB宿主103”中，UE 101-2通过无线接入链路接入IAB节点102-5，IAB节点102-5通过无线回传链路连接到IAB节点102-4，IAB节点102-4通过无线回传链路连接到IAB节点102-3，IAB节点102-3通过无线回传链路连接到IAB宿主103。
在本公开的上下文中，术语“接入IAB节点”可以指代UE接入的IAB节点，术语“中 间IAB节点”可以指代向UE或者IAB节点提供无线回传服务的IAB节点。例如，在图1所实施的示例中的路径“UE 101-2→IAB节点102-5→IAB节点102-4→IAB节点102-3→IAB宿主103”中，IAB节点102-5为接入IAB节点，IAB节点102-4和IAB节点102-3为中间IAB节点。应理解，IAB节点是接入IAB节点还是中间IAB节点并不是固定的，需要根据具体的应用场景确定。
在本公开的上下文中，术语“上游”、“下游”、“上一跳”和“下一跳”可以参考回传链路中数据流动的方向。例如，在路径“UE 101-2→IAB节点102-5→IAB节点102-4→IAB节点102-3→IAB宿主103”中，UE 101-2和IAB节点102-5可以被视为在IAB节点102-4的下游，并且IAB节点102-5可以被视为IAB节点102-4的下一跳节点。为讨论方便，下一跳节点也称为子节点，上一跳节点也称为父节点。而下游节点包括可以包括子节点、孙节点、等等，上游节点包括父节点等祖先节点。
IAB节点可以通过分布式架构来实现。例如，IAB节点节点可以包括MT(mobile termination，移动终端)部分和DU(distributed unit，分布式单元)部分，也分别称为IAB-MT和IAB-DU。当IAB节点面向其父节点时，可以作为终端设备，即作为MT；当IAB节点面向其子节点(子节点可能是另一IAB节点，或者普通UE)时，可以作为网络设备，即作为DU。IAB宿主可以通过分布式架构来实现，也可以通过集中式架构来实现。例如，IAB宿主可以是一个具有完整基站功能的接入网网元，也可以是集中式单元(centralized unit，CU)和分布式单元(distributed unit，DU)分离形态的接入网网元。为便于表述，可以将IAB宿主的集中式单元简称为宿主CU(donor CU，或直接称为CU)，并且可以将IAB宿主的分布式单元简称为宿主DU或donor DU。
当IAB节点连接到多个IAB宿主时，或者当IAB节点的MT部分和DU部分不属于同一个IAB宿主管理时，IAB节点的业务或者IAB节点下连接的UE的业务可能需要不同的节点进行传输。例如，在某个IAB节点的IAB-MT和IAB-DU都受某个IAB宿主CU(例如，表示为IAB donor CU1)管理时，可以使用IAB donor CU1所管理的该IAB节点来传输业务。在某个IAB节点的IAB-MT和IAB-DU分别连接到两个宿主CU(表示为IAB donor CU I和IAB donor CU2)时，可以使用由IAB donor CU1和IAB donor CU2共同管理的该IAB节点来传输业务。在某个IAB节点的IAB-MT和IAB-DU都受IAB donor CU2管理时，可以使用IAB donor CU2所管理的该IAB节点来传输业务。
在一些情况下，IAB节点需要在不同的IAB宿主之间切换。例如，IAB节点需要切换到目标IAB宿主所控制的小区，以获得更好的通信质量。当IAB节点切换到目标IAB宿主时，下游节点也可以切换到新的IAB宿主以保证UE的业务连续性。可以存在多种切换顺序。例如，自上而下(top-down)的切换顺序、自下而上(bottom-up)的切换顺序、或者任意的顺序。下面参考图2和图3来讨论IAB网络中的切换IAB宿主的示例过程。
首先参考图2，其示出了在IAB网络中按照自上而下的顺序切换IAB宿主的示例过程200。
如图2所示，过程200包括初始阶段201、自上而下切换的中间阶段202和最终阶段203。源IAB宿主211包括宿主CU212(标记为CU1)和宿主DU 213(标记为donor DU1)，目标IAB宿主214包括CU 215(标记为CU2)和donor DU 216(标记为donor DU2)。在初始阶段201，IAB节点221的MT 222(标记为MT1)和DU 223(标记为DU1a)连接到CU1，IAB节点224的MT 225(标记为MT2)和DU 226(标记为DU2b)连接到CU2，IAB节点227 的MT 228(标记为MT3)和DU 229(标记为DU3a)连接到CU1。
在自上而下切换的中间阶段202，IAB节点227在下游节点UE 230之前从IAB宿主211切换到IAB宿主214。IAB节点227启用由CU2控制的DU 232(标记为DU3b)。例如，DU3b可以首先与CU2建立通信接口(例如，F1接口)。CU1可以为DU3b分配IP地址，并且告诉DU3b这个IP地址用于与CU2通信，而不用于其他用途，例如，不用来与源CU1通信。这样，当IAB节点227接收到此IP地址，可以确定这是目标CU2发来的，是与DU3b通信的。如图2所示，当MT3从源CU1切换到目标CU2时，DU3a仍然连接到CU1。在这种情况下，IAB节点227仍然需要与CU1通信。因此，相关的数据分组需要经过IAB节点227、IAB节点224和Donor DU2的传输路径。此外，数据分组还将经由Donor DU2和CU1之间的IP网络而传输。
在最终阶段203，IAB节点227的MT3从源CU1切换到目标CU2，UE 230也从源CU1切换到目标CU2。
下面参考图3，其示出了在IAB网络中按照自下而上的顺序切换IAB宿主的示例过程300。
如图3所示，自下而上的切换过程300可以包括初始阶段201、自下而上切换的中间阶段302和最终阶段203。初始阶段201和最终阶段203与图2中所示的相同，故具体细节不再赘述。在自下而上切换的中间阶段302，IAB节点227在下游节点UE 230之后从IAB宿主211切换到IAB宿主214。如图3所示，当UE 230完成切换时，UE 230已经连接至由IAB宿主214的CU2控制的DU3b，但是IAB节点227的MT3仍然连接到IAB Donor CU1。在这种情况下，IAB节点227仍然需要与CU2通信。因此，相关的数据分组需要经过IAB节点227、IAB节点221和Donor DU1。此外，数据分组还将经由Donor DU1和CU2之间的IP网络而传输。
在图2和图3的示例中，进行切换的IAB节点为接入IAB节点，其子节点仅包括UE。在某些场景下，进行切换的IAB节点可以为能够为其他IAB节点提供无线回传的中间IAB节点。下面参考图4讨论这种场景下的切换IAB宿主的示例过程。
图4示出了在IAB网络中从中间IAB节点发起的自下而上切换IAB宿主的另一示例过程400。
过程400包括初始阶段401、第一中间阶段402、第二中间阶段403和最终阶段404。
在初始阶段401，中间IAB节点227确认从IAB宿主211切换到IAB宿主214，也即从连接CU1的IAB节点221切换至连接CU2的IAB节点224。IAB节点227及其下游的IAB节点410和UE 230需要一同切换至IAB节点224。
IAB节点424包括MT 425(标记为MT4)以及由CU1控制的DU 426(标记为DU4a)和由CU2控制的DU 427(标记为DU4b)。DU4a和DU4b同属IAB节点424，但是受不同的CU控制并且具有不同的配置。配置的示例可以包括：拓扑管理、路由管理和服务质量(QoS)管理等配置信息。配置信息可以由CU预先配置。例如，通过无线资源控制(RRC)或者F1应用协议(F1AP)信息来配置。在UE 230切换至DU4b时，相应地激活DU4b的对应配置。在第一中间阶段402，IAB节点424首先启用DU4b，具体过程与上面参考图2描述的IAB节点227启用DU3b的过程类似，故不再赘述。UE 230从由CU1控制的DU4a切换至由CU2控制的DU4b，而MT4仍然连接到CU1。
在第二中间阶段403，在UE 230已经切换至由CU2控制的DU4b之后，UE 230的父节 点IAB节点424的MT4从DU3a切换至DU3b。类似地，在MT4切换至DU3b时，相应地激活DU3b的对应配置。以此方式，IAB节点424切换到IAB宿主214。
在最终阶段404，在IAB节点424切换完成之后，IAB节点424的父节点IAB节点227的MT3从DU1a切换至DU2b。类似地，在MT3切换至DU2b时，相应地激活DU2b的对应配置。以此方式，IAB节点227切换到IAB宿主214。此时，IAB节点227及其下游的IAB节点424和UE 230完成从IAB宿主211切换到IAB宿主214的过程。
如上所述，在切换过程400中，在IAB节点227确认从IAB宿主211切换到IAB宿主214时，IAB节点227的下游节点(IAB节点424和UE 230)一同切换至IAB宿主214。在条件切换(Conditional Handover,CHO)过程中，IAB节点可以基于切换条件被满足来确认需要进行切换。切换条件可以是由网络预先配置的，并且与切换条件对应的配置信息也被预先配置。切换条件被满足可以是基于服务小区和邻区的信号质量而确定的。当切换条件时被满足时，IAB节点可以自行切换到目标IAB宿主所控制的小区而不需要网络触发。在条件切换过程中，当上游节点(例如，IAB节点227)达到切换条件(即，切换条件被满足)时，下游节点(例如，IAB节点424或UE 230)未必达到切换条件。换句话说，下游节点可能不会自动切换。然而，下游节点也应该及时地切换到目标IAB宿主，以避免上游节点已经切换而下游节点未切换的情况，从而保证业务的连续性。因此，需要能够使下游节点及时地与上游节点共同切换到目标IAB宿主的方案。
本公开的实施例提出了一种在IAB网络中进行切换的机制。根据该机制，在IAB节点确定从一个IAB宿主(称为“第一IAB宿主”)切换到另一个IAB宿主(称为“第二IAB宿主”)的条件已经满足时，该IAB节点向下一跳通信设备(其可以是另一IAB节点或者UE)发送切换到第二IAB宿主的指示或者向第一IAB宿主发送切换到第二IAB宿主的请求。
相应地，下游节点可以从上一跳IAB节点或第一IAB宿主接收从第一IAB宿主切换到第二IAB宿主的指示，并且执行到所述第二IAB宿主的切换。这样，下游节点可以及时地切换到目标IAB宿主。以此方式，保持了上下游节点切换的同步性，从而保证了业务的连续性。
图5示出了本公开的实施例可以在其中实施的示例环境500。
如图5所示，环境500可以为IAB网络的一部分，包括UE 510、IAB节点520、530和540以及IAB宿主550和560。在此示例中，UE 510可以经由IAB节点520、530和540与IAB宿主550或560通信。相应地，IAB节点520是接入IAB节点，IAB节点530和540是中间IAB节点。在环境500中，UE、IAB节点和IAB宿主之间能够以无线方式进行通信。该通信可以遵循任意适当通信技术以及相应的通信标准。
应当理解，图5中所示的UE、IAB节点和IAB宿主的数目和连接或耦合关系仅仅是示例而非限制。取决于具体实现和场景，可以有任意适当数目的UE、IAB节点和IAB宿主，其可以具有任意适当的连接或耦合关系。
在环境500中，IAB节点520、530和540以及IAB宿主550和560都是以分布方式实现的。如图5所示，IAB节点520可以包括DU 521和MT 522，IAB节点530可以包括DU 531和MT 532，并且IAB节点540可以包括DU 541和MT 542。IAB宿主550可以包括宿主DU 551和CU 552，并且IAB宿主560可以包括宿主DU 561和CU 562。CU 552和562都可以是控制面(control plane，CP)和用户面(user plane，UP)分离的形态。例如，CU 552可以包括一个CU-CP 553和一个CU-UP 554，CU 562可以包括一个CU-CP 563和一个CU-UP 564。 应当理解，图5示出的一个CU包括一个CU-UP仅仅是示例，而非限制。在某些实施例中，一个CU可以包括一个CU-CP和多个CU-UP。
IAB网络可以为独立组网(SA)的IAB网络或非独立组网(NSA)的IAB网络。在SA模式下，CU-CP 553可以通过NG控制面接口NG-C连接到5GC 590中的控制面网元，例如接入和移动性管理功能(AMF)。CU-UP 554可以通过NG用户面接口NG-U连接到5GC 590中的用户面网元，例如用户面功能(UPF)。5GC 590可以通过NG接口连接到5G基站gNB 570。gNB 570可以和5GC 590之间建立用户面和/或控制面的接口。gNB 570和IAB宿主550可以为IAB节点(例如，IAB节点540)提供双连接服务。例如，gNB 570可以作为IAB节点540的主基站的角色或者辅基站的角色。gNB 570与IAB节点的MT之间有NR-Uu空口连接。
在NSA模式下，CU-UP 554可以通过S1用户面接口S1-U连接到4G核心网EPC 580，例如连接到业务网关(serving gateway，SGW)。NSA模式也称为演进通用地面无线电接入(Evolved Universal Terrestrial Radio Access，E-UTRA)新无线电(New Radio，NR)双连接(Dual Connectivity)或EN-DC模式。EPC 580通过S1接口(包括S1接口用户面以及S1接口控制面)连接到LTE基站MeNB 570。MeNB 570与CU-UP 554之间有X2-C接口。MeNB 570和IAB宿主540可以为IAB节点(例如，IAB节点540)提供双连接服务。例如，MeNB 570可以作为IAB节点540的主基站。MeNB 570与IAB节点的MT之间有LTE Uu空口连接。
此外，每个IAB节点520、530和540的DU 521、531和541与CU 552和560之间都有用于通信的F1接口(图5中未示出)。
下文参考图6a和6b来描述IAB网络的控制面协议栈和用户面协议栈的示例架构。
图6a示出了根据本公开的某些实施例的IAB网络的控制面协议栈的示例架构600。
如图6a所示，对于控制面而言，UE 510和IAB节点520的DU 521之间建立有Uu接口，对等的协议层包括RLC层、MAC层和PHY层。IAB节点520的DU 521和IAB宿主550的CU 552之间建立有F1-C接口，对等的协议层包括F1应用协议(F1application protocol，F1AP)层、流控制传输协议(Stream Control Transmission Protocol，SCTP)层。IAB宿主550内的宿主DU 551和CU 552之间通过有线连接，对等的协议层包括互联网协议IP(internet protocol)层、L2和L1。IAB节点520和IAB节点530之间、IAB节点530和IAB节点540之间，以及IAB节点540和IAB宿主550内的宿主DU 551之间均建立有回传(BL)链路，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，UE 510和CU 552之间建立有对等的RRC层和PDCP层，IAB节点520的DU 521和IAB宿主550内的宿主DU 551之间建立有对等的IP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-DU的功能(即与UE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层的功能)。即，IAB网络中接入IAB节点的DU实现了单空口的gNB-DU的功能，IAB donor CU(例如CU 552)实现了单空口的gNB-CU的功能。
在控制面上，RRC消息封装在接入IAB节点和IAB donor CU之间的F1AP消息中传输。具体地，在上行方向上，UE 510将RRC消息封装在PDCP协议数据单元(protocol data unit，PDU)中，并依次经过RLC层、MAC层和PHY层的处理后发送至IAB节点520的DU 521。IAB节点520的DU 521依次经过PHY层、MAC层和RLC层的处理后得到PDCP PDU，将 PDCP PDU封装在F1AP消息中，并依次经过SCTP层、IP层处理后得到IP包，IAB节点520的MT 522将IP包分别通过BAP层、RLC层、MAC层和PHY层的处理后发送至IAB节点530的DU 531。IAB节点530的DU 531依次经过PHY层、MAC层、RLC层和BAP层的处理后得到IP包，然后IAB节点530的MT 532采用类似于MT 522的操作，将该IP包发送至IAB节点540的DU 541，同理，IAB节点540的MT 542将该IP包发送至IAB宿主550内的宿主DU 551。IAB宿主550内的宿主DU 551解析得到IP包后，将该IP包发送至IAB宿主550的CU 552，CU 552将该IP包依次通过SCTP层、F1AP层和PDCP层的处理后得到RRC消息。下行方向类似，在此不再描述。
图6b示出了根据本公开的某些实施例的IAB网络的用户面协议栈的示例架构610。
如图6b所示，对于用户面而言，UE 510和IAB节点520的DU 521之间建立有Uu接口，对等的协议层包括RLC层、MAC层和PHY层。IAB节点520的DU 521和IAB宿主550的CU 552建立有F1-U接口，对等的协议层包括GPRS用户面隧道协议(GPRS tunnelling protocol for the user plane，GTP-U)层、用户数据报协议(user datagram protocol，UDP)层。IAB宿主550内的宿主DU 551和CU 552之间通过有线连接，对等的协议层包括IP层、L2和L1。IAB节点520和IAB节点530之间、IAB节点530和IAB节点540之间，以及IAB节点540和IAB宿主550内的宿主DU 551之间均建立有BL链路，对等的协议层包括BAP层、RLC层、MAC层以及PHY层。另外，UE 510和CU 552之间建立有对等的SDAP层和PDCP层，IAB节点520的DU 521和IAB宿主550内的宿主DU 551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(例如IAB节点520)的DU实现了单空口的gNB-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CU建立对等的GTP-U层、UDP层的功能)。可以理解，IAB接入节点的DU实现了单空口的gNB-DU的功能；IAB donor CU实现了单空口的gNB-CU的功能。
在用户面上，PDCP数据包封装在接入IAB节点和IAB donor CU(例如CU 552)之间的GTP-U隧道中传输。GTP-U隧道建立在F1-U接口上。
应当理解，仅仅出于说明的目的而无意于提出任何限制，在图5以及图6a和6b示出并且参考图5以及图6a和6b描述了UE 510、IAB节点520、530和540以及IAB宿主550和560的结构和协议栈架构。可以实施本公开的实施例的IAB节点和IAB宿主可以具有任意适当的其他结构以及任意适当的其他协议栈架构。当前已知以及将来开发的关于IAB网络中的通信设备的任何结构和协议架构都可以在此使用，本公开的范围在此方面不受限制。作为示例，在某些实施例中，IAB节点520、530和/或540可以通过集中式架构来实现，例如可以具有完整基站功能，同样，IAB宿主550和560可以集中式地实现为具有完整基站功能。
在本公开的各实施例中，IAB节点520、530和540可以在IAB宿主550和IAB宿主560之间执行条件切换。例如，当IAB节点530确定从IAB宿主550切换到IAB宿主560的条件已经满足后，向下一跳IAB节点520发送切换到IAB宿主560的指示，或者向IAB宿主550发送切换到IAB宿主560的请求。相应地，下游的IAB节点520可以基于来自上一跳IAB节点530或者IAB宿主550的切换指示，执行到IAB宿主560的切换。以此方式，上下游节点可以同步地执行切换，从而保证了业务的连续性。
图7示出了根据本公开的某些实施例的在发起跨IAB宿主切换的IAB节点处实施的切换 方法700的流程图。方法700可以由图5中的IAB节点520、530或540来执行。为讨论方便，以下将参考图5，结合IAB节点530发起从IAB宿主550切换到IAB宿主560的场景来描述方法700。
如图7所示，在框705，第一IAB节点(例如，IAB节点530)确定从第一IAB宿主(IAB宿主550)切换到第二IAB宿主(IAB宿主560)的条件已经满足。切换条件可以是在网络中预先配置的。例如，可以由网络管理系统，例如IAB宿主节点来预配置该切换条件。切换条件可以与服务小区和邻区的信号质量相关联。例如，可以基于由第一IAB宿主控制的服务小区的信号质量与由第二IAB宿主控制的邻区的信号质量的差值低于预定阈值来确定满足切换条件。该阈值也是可以由网络管理系统预配置的。为讨论方便，下文中，第一IAB宿主也称为源IAB宿主，第二IAB宿主也称为目标IAB宿主。第一IAB节点将切换到的由第二IAB宿主控制的小区也称为目标小区。
在框710，第一IAB节点向下一跳通信设备(例如，IAB节点520)发送切换到第二IAB宿主的指示以指示下一跳通信设备切换到第二IAB宿主，或者向第一IAB宿主发送切换到第二IAB宿主的请求。取决于IAB网络的拓扑结构，第一IAB节点的下一跳通信设备可以是作为第一IAB节点的子节点的IAB节点或UE。例如，当IAB节点530作为第一IAB节点时，下一跳通信设备是IAB节点520。当IAB节点520作为第一IAB节点时，下一跳通信设备是UE 510。
根据本公开的某些实施例，第一IAB节点可以直接向下一跳通信设备发送切换到第二IAB宿主的指示。在某些实施例中，第一IAB节点可以通过回传适配协议(BAP)层控制分组数据单元(PDU)或媒体接入控制(MAC)控制元素(CE)将切换指示发送给下一跳通信设备。例如，可以由IAB节点530将包括由目标IAB宿主控制的目标小区的预配置信息的索引信息的指示利用BAP层控制PDU或MAC CE来发送给下一跳通信设备IAB节点520。
如果第一IAB节点具有多个下一跳通信设备，则第一IAB节点可以向所有下一跳通信设备发送切换到第二IAB宿主的指示。在向下一跳通信设备发送了切换到第二IAB宿主的指示之后，第一IAB节点可以执行到第二IAB宿主的切换。例如，在IAB节点530向下一跳通信设备IAB节点520发送了切换指示之后，IAB节点530可以执行到目标IAB宿主的切换。相应地，下一跳通信设备也可以基于该指示执行到第二IAB宿主的切换，以此实现了上下游设备的同步切换。
作为示例，第一IAB节点可以通过随机接入过程来实现到目标IAB宿主的目标小区的切换。例如，第一IAB节点可以执行四步随机接入过程或两步随机接入过程来接入目标小区。当第一IAB节点的随机接入成功时，则可以确定切换完成。
在某些实施例中，第一IAB节点可以响应于从下一跳通信设备接收到切换完成的指示而执行到第二IAB宿主的切换。例如，在IAB节点530向下一跳通信设备IAB节点520发送了切换指示之后，如果IAB节点530从IAB节点520接收到切换完成的指示，则IAB节点530可以执行到目标IAB宿主的切换。
应当理解，由于IAB节点520也具有下一跳通信设备UE 510，因此IAB节点520可以基于来自IAB节点530的切换指示，触发其子节点UE 510的切换，在接收到UE 510的切换完成的指示之后才进行切换。换句话说，在IAB节点530向下一跳通信设备IAB节点520发送了切换指示之后，IAB节点520可以向其下游节点UE 510转发切换指示。IAB节点520可 以响应于接收到UE 510切换完成的指示而执行到目标IAB宿主的切换。继而，IAB节点530可以响应于IAB节点520切换完成的指示而执行到目标IAB宿主的切换。后文将结合图8对IAB节点520的操作进一步说明。
在某些实施例中，在第一IAB节点向下一跳通信设备发送切换到第二IAB宿主的指示之后，第一IAB节点可以直接执行到第二IAB宿主的切换而无需接收切换完成的指示。例如，在IAB节点530向下一跳通信设备IAB节点520发送了切换指示之后，IAB节点530可以直接执行到目标IAB宿主的切换，而无需等待下游节点IAB节点520和UE 510的切换完成的指示。以此方式，可以进一步降低切换时延，提高切换效率。
在某些实施例中，在向下一跳通信设备发送的切换到第二IAB宿主的指示中可以包括由第二IAB宿主控制的目标小区的预配置信息的索引信息。如上所述，在IAB节点或UE中可以包括从IAB宿主接收预配置信息，其可以包括拓扑管理、路由管理和QoS管理等。不同的通信设备的预配置信息可以不同，但可以对应相同的索引信息。索引信息可以与目标小区的标识相关联。这样，在下一跳通信设备接收到切换指示时，可以根据目标小区的标识确定要切换到哪一个目标小区。索引信息还可以与第一IAB节点相关联，这样可以根据第一IAB节点的标识确定是哪一个上游节点需要切换。以此方式，下一跳通信设备可以相应地激活与索引信息对应的预配置信息，也即，使与索引信息对应的预配置信息生效，而不需要IAB宿主的CU重新下发配置信息，从而可以降低时延。
除了直接向下一跳通信设备发送切换指示之外，根据本公开的某些其他实施例，第一IAB节点可以向第一IAB宿主发送切换到第二IAB宿主的请求。继而，由第一IAB宿主集中控制第一IAB节点及其下游通信设备到第二IAB宿主的切换。后文将结合图11和图12对第一IAB宿主的操作进行详细说明。
在此场景下，第一IAB节点可以从第一IAB宿主接收第一IAB节点的下一跳通信设备已经切换到第二IAB宿主的指示。第一IAB节点可以在从第一IAB宿主接收到下一跳通信设备已经切换到第二IAB宿主的指示之后执行到第二IAB宿主的切换。例如，在IAB节点530向IAB宿主550发送了请求之后，如果IAB节点530从IAB宿主550接收到IAB节点520切换完成的指示，则IAB节点530可以执行到目标IAB宿主的切换。
在某些实施例中，在向第一IAB宿主发送的切换到第二IAB宿主的请求中可以包括第二IAB宿主所控制的目标小区的标识，以向第一IAB宿主通知切换的目标小区。相应地，第一IAB宿主可以向第一IAB节点的下游节点通知切换的目标小区，以使得第一IAB节点的下游节点可以切换到与目标小区对应的目标IAB宿主。
如上所述，在CHO过程中，切换条件可以是预先配置的。因此，IAB节点可能会遇到配置冲突的问题。在某些实施例中，第一IAB节点可能与其上游节点(或设备)同时触发条件切换。例如，在确定切换到第二IAB宿主的条件已经满足的同时，第一IAB节点(例如，IAB节点530)从上一跳IAB节点(例如，IAB节点540)接收切换到不同的第三IAB宿主的指示。例如，在IAB节点530自身触发切换并且确定切换到IAB宿主560时，IAB节点530还可能接收到来自上游IAB节点540的、由于IAB节点540触发切换条件而导致的切换到另外的IAB宿主(未示出)的指示。
在这种情况下，第一IAB节点也可以向第一IAB宿主发送切换到第二IAB宿主的请求，可以由第一IAB宿主来进行切换决策和冲突解决。例如，IAB节点530可以在触发切换条件 时向所属的IAB宿主550发送切换请求。切换请求中可以包括目标小区的标识。同时，IAB节点540也可以向IAB宿主550发送携带目标小区的标识的切换请求。这样，可以由第一IAB宿主来决定切换到哪个小区以及采用哪套配置。
备选地或附加地，第一IAB节点可以具有切换优先权。例如，第一IAB节点及其下游节点可以先切换到第二IAB宿主，继而上一跳IAB节点再进行切换。例如，IAB节点530及其下游节点可以先切换到由IAB节点530自身触发切换而确定的IAB宿主560。继而，上游节点IAB节点540再进行切换。在这种情况下，可能出现IAB节点540的MT和DU部分分别由不同的IAB宿主管理的情况。
备选地或附加地，上游IAB节点可以具有切换优先权。例如，第一IAB节点及其下游节点遵从上一跳IAB节点的切换判决，先切换到与第二IAB宿主不同的第三IAB宿主。继而，第一IAB节点再根据切换条件判断是否要继续执行切换。例如，IAB节点540及其下游节点(包括IAB节点530)可以先切换到由IAB节点540自身触发切换而确定的第三IAB宿主。继而，IAB节点530可以基于由切换到的第三IAB宿主控制的小区和邻区的通信质量来确定切换条件是否被满足，从而确定是否仍然要进行切换。后文将结合图8对此方面的实施例进一步说明。
图8示出了根据本公开的某些实施例的在发起跨IAB宿主切换的IAB节点的下游通信设备处实施的切换方法的流程图800。方法800可以由图5中的IAB节点520、530或540来执行。为讨论方便，以下将参考图5，结合IAB节点530发起从IAB宿主550切换到IAB宿主560的场景来描述方法800。在上述场景中，方法800可以由IAB节点520来执行。
如图8所示，在框805，第二IAB节点(例如，IAB节点520)从上一跳IAB节点(例如，IAB节点530或IAB节点520)接收从第一IAB宿主切换到第二IAB宿主(IAB宿主560)的指示。到第二IAB宿主的切换是由位于第二IAB节点上游的第一IAB节点(例如，IAB节点530)基于切换到第二IAB宿主的条件已经满足而触发的。相应地，该切换指示由第一IAB节点或第一IAB宿主(IAB宿主550)生成。上一跳IAB节点可以与或者可以不与第一IAB节点相同。例如，在IAB节点530作为第一IAB节点的实施例中，当第二IAB节点由IAB节点520来实现时，其上一跳IAB节点与第一IAB节点是同一节点，都是IAB节点530。当第一IAB节点由IAB节点540来实现并且第二IAB节点由IAB节点520来实现时，其上一跳IAB节点是IAB节点530，与作为第一IAB节点的IAB节点540不同。
在框810，第二IAB节点向下一跳通信设备(例如，UE 510)转发切换到第二IAB宿主的指示。
在某些实施例中，第二IAB节点可以首先判断是否具有下一跳设备。如果第二IAB节点具有下一跳通信设备，第二IAB节点在执行到第二IAB宿主的切换之前，可以向第二IAB节点的下一跳通信设备转发切换到第二IAB宿主的指示。第二IAB节点可以响应于从其下一跳通信设备接收到切换完成的指示而执行到第二IAB宿主的切换。例如，在第二IAB节点由具有下一跳通信设备UE 510的IAB节点520实现的实施例中，第二IAB节点520可以在切换到目标IAB宿主560之前向下一跳通信设备UE 510发送切换到相同的目标IAB宿主560的指示。在这种情况下，第二IAB节点520可以响应于从UE 510接收到切换完成的指示而执行到目标IAB宿主560的切换。以此方式，可以使第二IAB节点及其下游节点(包括子节点、孙节点等等)共同切换到作为切换目标的第二IAB宿主。
作为备选，第二IAB节点可以不等待来自下游节点的切换完成指示，而直接执行到第二IAB宿主的切换。在另一些实施例中，在第二IAB节点不具有下一跳的实施例中，第二IAB节点可以直接执行到第二IAB宿主的切换。
在完成切换之后，第二IAB节点可以向上一跳IAB节点发送切换完成的指示。作为示例，切换完成的指示可以是通过上游节点接力传递给IAB宿主的RRC消息。以此方式，上游节点在收到下游节点的RRC消息后，可以根据消息类型来确定下游节点已经完成切换。例如，在UE 510切换到目标IAB宿主560之后，可以向上一跳的IAB节点520发送切换完成的指示。IAB节点520在切换到目标IAB 560之后，可以向上一跳的IAB节点530发送切换完成的指示。
在由第一IAB宿主对切换进行集中控制的实施例中，第二IAB节点可以从上一跳IAB节点接收由第一IAB宿主生成的到从第一IAB宿主切换到第二IAB宿主的指示。如上所述，第一IAB宿主可以响应于第二IAB节点的切换请求而生成该指示并向第二IAB节点发送该指示。例如，如果在第二IAB节点从上一跳IAB接收到切换到第二IAB宿主的指示的同时确定切换到不同的第四IAB宿主的条件已经满足，可以向第一IAB宿主发送切换到第四IAB宿主的请求，以便由第一IAB宿主来进行切换决策和冲突解决。该切换请求中可以包括切换的目标小区。相应地，在第一IAB宿主决定切换到哪个IAB宿主或者哪个小区之后，可以向第二IAB节点发送切换指示。应理解，由第一IAB宿主生成的并向第二IAB节点发送的切换指示可以由第二IAB节点的上游节点逐级转发给第二IAB节点，因此第二IAB节点可以从上一跳IAB节点接收第一IAB宿主所生成的切换指示。
备选地或附加地，在下游的第二IAB节点与上游的第一IAB节点的切换判决发生冲突时，上游IAB节点可以具有切换优先权。例如，下游的第二IAB节点遵从第一IAB节点的切换判决，先切换到与第二IAB宿主。继而，第二IAB节点再根据切换条件判断是否要继续执行切换。备选地或附加地，下游的第二IAB节点可以具有切换优先权。例如，第二IAB节点可以先切换到第四IAB宿主，继而上一跳IAB节点再进行切换。
在某些实施例中，第一IAB宿主向第二IAB节点发送的切换指示可以由第二IAB节点的上游节点的切换请求而触发。例如，在第二IAB节点由IAB节点520实现的实施例中，在其上游IAB节点530基于切换条件判决向充当第一IAB宿主的IAB宿主550发送了到充当第二IAB宿主的IAB宿主560的切换请求之后，IAB节点520可以从IAB宿主550接收响应于IAB节点530的切换请求的指示。
在某些实施例中，在切换到第二IAB宿主的指示中可以包括第二IAB节点从第一IAB宿主接收的预配置信息的的索引信息。索引信息可以与目标小区相关联。如上所述，IAB节点或UE可以从IAB宿主接收预配置信息，该预配置信息可以包括拓扑管理、路由管理和QoS管理等。不同的通信设备的配置信息可以不同，但可以对应相同的索引信息。这样，第二IAB节点在接收到切换指示后，可以使与索引信息相关联的预配置信息生效以使用该预配置信息来执行切换。例如，可以根据与索引信息相对应的目标小区的标识确定要切换到哪一个目标小区。在索引信息与第一IAB节点相对应的实施例中，第二IAB节点还可以确定是哪一个上游节点需要切换。继而，通信设备可以通过使相对应的预配置生效来执行切换。以此方式，通信设备可以相应地激活对应的配置信息，而不需要IAB宿主的CU重新下发配置信息，从而可以节省系统开销并且降低时延。
应理解，上文结合图7描述方法700时描述的操作和特征，特别是与第一IAB节点(例如，IAB节点530)的下一跳通信设备(例如，IAB节点520)有关的操作和特征，同样适用于方法800，并且具有同样的效果，具体细节不再赘述。
下面结合图9和图10讨论根据本公开的某些实施例的由发起跨IAB宿主切换的IAB节点直接向下一跳通信设备发送切换指示的示例切换过程。
首先参考图9，其示出了根据本公开的某些实施例在环境500中由IAB节点530发起从IAB宿主550到560切换时的示例切换过程900。
如图9所示，在过程900中，IAB节点530(作为第一IAB节点)的MT 532确定(902)达到从IAB宿主550(作为第一IAB宿主)切换到IAB宿主560(作为第二IAB宿主)的条件。IAB节点530的MT 532指示DU 531向下一跳IAB节点520发送(904)切换到IAB宿主560的指示。指示可以通过BAP层控制PDU或MAC CE传递。在某些实施例中，指示中可以携带IAB节点530需要激活的配置信息或对应的索引信息。配置信息可以是目标IAB宿主560的CU 562控制下的DU2b处的配置信息，例如：拓扑管理，路由管理和QoS管理信息。取决于要切换到的目标小区，IAB节点530可以有对应的不同配置。不同的配置可以对应不同的索引。IAB节点530可以根据目标小区选择对应的配置。配置信息可以预先由源IAB宿主550的CU 552发送给IAB节点530。IAB宿主550的CU 55还可以以IAB节点530为头节点，针对其可以切换的不同目标小区，预先给IAB节点530的下游节点(包括IAB节点520和UE 510)发送配置信息。不同节点的配置信息可以不同，但可以对应相同的索引信息。索引信息可以用IAB节点的ID和目标小区ID来区分。这样，下游节点在收到切换指示时，可以确定哪一个上游节点需要切换以及目标小区是哪一个。这样，可以采用对应的配置信息而不需要IAB宿主550的CU 552重新下发配置信息，从而降低了时延。
IAB节点520在接收到IAB节点530所发送的指示之后，确定(906)是否具有下一跳节点。在此示例中，IAB节点520的下游还有UE 510。相应地，IAB节点520向下游UE 510转发(908)切换到IAB宿主560的指示。由于UE 510不具有下游节点，所以UE 510在接收到切换指示之后，执行切换(910)。在UE 510完成切换之后，可以向上一跳的IAB节点520发送(912)切换完成指示。IAB节点520可以确定(914)是否已经接收到所有下一跳节点(包括UE 510)的切换完成指示。在IAB节点520确定(914)已经接收到所有下一跳节点的切换完成指示之后，IAB节点520可以切换(918)到目的IAB宿主560。之后，IAB节点520可以向IAB节点530发送(920)切换完成指示。在IAB节点530确定(922)已经接收到所有下一跳节点(包括IAB节点520)的切换完成指示之后，IAB节点530可以切换(924)到目的IAB宿主560。
图10示出了根据本公开的某些实施例在环境500中由IAB节点530发起从IAB宿主550到560切换时的另一示例切换过程1000。与图9所示的第一过程900的不同之处在于，上游节点(例如，IAB节点530)向下游节点(例如，IAB节点520)发送切换到目标IAB宿主560的指示之后，上游节点可以直接执行切换而无需等待接收下游节点的切换完成的指示。
如图10所示，在过程1000中，IAB节点530的MT 532确定(1002)达到从IAB宿主550切换到IAB宿主560的条件。IAB节点530的MT 532指示DU 531向下一跳IAB节点520发送(1004)切换到IAB宿主560的指示。类似地，指示可以包括参考图9所描述的配置信息或对应的索引信息。在此示例中，IAB节点530在向下一跳IAB节点520发送了切换 指示之后，直接激活对应的配置以切换(1006)到IAB宿主560。具体地，IAB节点530的MT 532进行切换，从由IAB宿主550控制的上游节点的DU切换到由IAB宿主560控制的上游节点的DU。IAB节点520在接收到IAB节点530所发送的指示之后可以确定(1008)是否具有下一跳设备。由于IAB节点520具有下游设备UE 510，则IAB节点520向下游UE510转发(1010)切换到IAB宿主560的指示。在向下游的UE 510发送指示之后，IAB节点520可以激活对应的配置以切换(1012)到IAB宿主560。类似地，IABIAB节点520的MT 522进行切换，从由IAB宿主550控制的上游节点的DU切换到由IAB宿主560控制的上游节点的DU。UE 510可以在接收到来自IAB节点520的指示之后切换(1014)到IAB宿主560。
如前所述，可以由在切换过程中作为源IAB宿主的第一IAB宿主来集中控制第一IAB节点及其下游通信设备到作为目的IAB宿主的第二IAB宿主的切换。下面参考图11和图12来描述此方面的具体实施例。
图11示出了根据本公开的某些实施例的在IAB宿主处实施的切换方法1100的流程图。方法1100可以由图5中的IAB宿主550或IAB宿主560来执行。为讨论方便，以下将参考图5，结合由IAB节点530发起从IAB宿主550到IAB宿主560的切换的场景来描述方法1100。
如图11所示，在框1105，第一IAB宿主(例如，IAB宿主550)从第一IAB节点(例如，IAB节点530)接收切换到第二IAB宿主(例如，IAB宿主560)的请求。到第二IAB宿主的切换是由第一IAB节点基于切换到第二IAB宿主的条件已经满足而触发的。切换条件可以是网络预先配置的。在切换到第二IAB宿主的请求中可以包括第二IAB宿主所控制的目标小区的标识。
在框1110，第一IAB宿主按照自下而上的顺序向第一IAB节点下游的通信设备发送切换到第二IAB宿主的指示。在某些实施例中，第一IAB宿主可以首先向第一IAB节点下游的末端通信设备发送切换到第二IAB宿主的指示。末端通信设备可以是UE或者不具有下游节点的IAB节点。在末端通信设备已经切换到第二IAB宿主之后，第一IAB宿主可以向位于第一IAB节点下游的末端通信设备的上一跳通信设备发送切换到第二IAB宿主的指示。例如，在末端设备为UE 510的情况下，第一IAB宿主550可以先向UE 510发送切换指示。在第一IAB宿主550接收到UE 510切换完成的指示之后，第一IAB宿主550可以向UE 510的上一跳节点，即IAB节点520发送切换指示。
在某些实施例中，在切换到第二IAB宿主的指示中可以包括由第二IAB宿主控制的目标小区的预配置信息的索引信息。索引信息与目标小区相关联。在这种情况下，节点可以根据索引信息确定要激活的配置。在某些实施例中，可以由第一IAB宿主向第一IAB节点下游的通信设备发送预配置信息。例如，在向第一IAB节点下游的通信设备发送切换到第二IAB宿主的指示之前，第一IAB宿主可以向第一IAB节点下游的通信设备发送预配置信息。这样，第一IAB节点下游的通信设备被预先配置，从而能够基于所接收的索引信息确定哪套配置生效，以用来执行到第二IAB宿主所控制的目标小区的切换。
备选地或附加地，在切换到第二IAB宿主的指示中可以包括用于切换到第二IAB宿主所控制的目标小区的配置信息。这样，第一IAB节点下游的通信设备被可以在未预先配置的情况下能够使用所接收的配置信息来执行到第二IAB宿主所控制的目标小区的切换。
在框1115，在第一IAB节点的下一跳通信设备已经切换到第二IAB宿主之后，第一IAB宿主向第一IAB节点发送第一IAB节点的下一跳通信设备已经切换到第二IAB宿主的指示。 例如，在第一IAB节点(例如，IAB节点530)下游的所有设备(包括IAB节点520和UE 510)都完成切换之后，第一IAB宿主确定第一IAB节点的下一跳通信设备已经切换到第二IAB宿主，继而可以向第一IAB节点发送上述指示。
在某些实施例中，除了接收到来自第一IAB节点的切换请求，第一IAB宿主(例如，IAB宿主550)还可以接收到来自其它一个或多个IAB节点的切换请求。例如，在CHO过程中，IAB节点530和IAB节点540可能同时触发切换条件。如果多个IAB节点的目的IAB宿主不同，第一IAB宿主可以进行切换判决，确定到底切换到哪个目的IAB宿主和/或哪个目的小区。在这种情况下，第一IAB宿主向各个IAB节点发送的切换指示中可以包括要切换到的小区的标识、配置信息或对应的索引信息。这样，各IAB节点可以同步切换，避免了冲突。
应理解，上文结合图7描述方法700和结合图8描述方法800时描述的操作和特征，同样适用于方法1100，并且具有同样的效果，具体细节不再赘述。
图12示出了根据本公开的某些实施例的在环境500中由IAB宿主550集中控制由IAB节点530发起的从IAB宿主550到560的示例切换过程1200。
如图12所示，在过程1200中，IAB节点530的MT 532确定(1202)达到从IAB宿主550切换到IAB宿主560的条件。到IAB宿主560的切换是由IAB节点530基于切换到IAB宿主560的条件已经满足而触发的。IAB节点530向IAB宿主550的CU 552发送(1204)从IAB宿主550切换到IAB宿主560的请求。请求中可以包括IAB宿主560所控制的目标小区的标识。IAB宿主550按照自下而上的顺序向IAB节点530下游的通信设备(包括UE 510和IAB节点520)发送切换到IAB宿主560的指示。指示可以包括用于切换到IAB宿主560所控制的目标小区而要激活的配置的索引信息。索引信息与IAB节点530和目标小区相关联。指示也可以直接包括与下游通信设备(例如，UE 510或IAB节点520)对应的配置信息。
IAB宿主550可以首先向IAB节点530下游的末端通信设备UE 510发送(1210)切换到IAB宿主560的指示。例如，IAB宿主550的CU 552可以向UE 510发送切换指示。取决于各个节点或设备是否预先存储有CHO之后的配置信息(例如，拓扑，路由，QoS管理信息)，切换指示可以有以下的可能情况。在接收切换指示的节点有预先配置的情况下，指示可以包括配置信息对应的索引。索引可以与IAB头节点(即，IAB节点530)ID和目标小区ID相关联，因此接收设备可以根据索引来激活相关配置。在接收切换指示的节点无预先配置的情况下，指示可以包括与接收设备对应的配置信息。这样，接收设备可以直接采用由IAB宿主550的CU 552下发的配置信息来激活对应的配置。
在从IAB宿主550(例如CU 552)接收到切换指示后，UE 510可以基于指示激活对应的配置以从IAB宿主550切换(1208)到IAB宿主560。UE 510可以在切换完成之后向IAB宿主550发送(1210)切换完成的指示。IAB宿主550可以在接收到UE 510的切换完成的指示之后，向UE 510的上一跳节点IAB节点520发送(1212)切换指示。IAB节点520可以基于指示切换(1214)到IAB宿主560。IAB节点520可以在切换完成之后向IAB宿主550发送(1216)切换完成的指示。类似地，IAB宿主550可以依次向IAB节点530下游的通信设备发送切换指示。基于IAB宿主550确定(1218)IAB节点530的所有下游节点已经完成切换，IAB宿主550可以向IAB节点530发送(1220)下游节点切换完成的指示。IAB宿主550的CU 552可以指示IAB节点530的MT 532从IAB宿主550的CU 552切换到IAB宿主560的CU 562。IAB节点530可以基于下游节点切换完成的指示切换(1222)到IAB宿主560， 从而完成整体切换过程。
以此方式，可以在IAB节点触发CHO时，及时地指示其下游节点自下而上地进行切换，从而保证UE的业务连续性。
本公开的实施例还提供了用于实现上述方法或过程的相应装置。
图13示出了根据本公开的某些实施例的在发起跨IAB宿主切换的IAB节点处的装置1300的示意性结构框图。
如图13所示，装置1300包括条件确定模块1305，被配置为通过第一IAB节点确定从第一IAB宿主切换到第二IAB宿主的条件已经满足；第一发送模块1310，被配置为通过第一IAB节点向下一跳通信设备发送切换到第二IAB宿主的指示以指示下一跳通信设备切换到第二IAB宿主，或者向第一IAB宿主发送对于切换到第二IAB宿主的请求。
在某些实施例中，在第一发送模块1310被配置为通过第一IAB节点向下一跳通信设备发送切换到第二IAB宿主的指示的情况下，该装置1300还包括：第一切换模块，第一切换模块被配置为响应于第一IAB节点从下一跳通信设备接收到切换完成的指示，通过第一IAB节点执行到第二IAB宿主的切换。
在某些实施例中，在切换到第二IAB宿主的指示中包括与由第二IAB宿主控制的目标小区的预配置信息的索引信息，以使得下一跳通信设备使预配置信息生效以切换到目标小区。
在某些实施例中，切换到第二IAB宿主的指示由第一IAB节点通过回传适配协议BAP层控制分组数据单元PDU或媒体接入控制MAC控制元素CE发送给下一跳通信设备。
在某些实施例中，在第一发送模块1310被配置为通过第一IAB节点向第一IAB宿主发送切换到第二IAB宿主的请求的情况下，该装置1300还包括指示接收模块和第二切换模块。指示接收模块被配置为通过第一IAB节点从第一IAB宿主接收第一IAB节点的下一跳通信设备已经切换到第二IAB宿主的指示。第二切换模块被配置为通过第一IAB节点执行到第二IAB宿主的切换。
应理解，上文结合图5至图12描述的在第一IAB节点处的操作和特征同样适用于装置1300，并且具有同样的效果，具体细节不再赘述。
图14示出了根据本公开的某些实施例的在发起跨IAB宿主切换的IAB节点的下游通信设备处的装置1400的示意性结构框图。
如图14所示，装置1400包括第一接收模块1405和转发模块1410。第一接收模块1405被配置为通过第二IAB节点从上一跳IAB节点接收从第一IAB宿主切换到第二IAB宿主的指示。转发模块1410被配置为通过第二IAB节点向下游通信设备转发从第一IAB宿主切换到第二IAB宿主的指示，以指示下游通信设备从第一IAB宿主切换到第二IAB宿主。
在某些实施例中，该装置1400还包括第一切换模块。第一切换模块被配置为响应于第二IAB节点从下一跳通信设备接收到切换完成的指示，通过第二IAB节点执行到第二IAB宿主的切换。
在某些实施例中，在从第一IAB宿主切换到第二IAB宿主的指示中包括第二IAB节点从第一IAB宿主接收的预配置信息的索引信息，索引信息与由第二IAB宿主控制的目标小区相关联。第一切换模块包括配置生效模块，配置生效模块被配置为通过第二IAB节点使预配置信息生效以切换到目标小区。
应理解，上文结合图5至图12描述的在第二IAB节点处的操作和特征同样适用于装置 1400，并且具有同样的效果，具体细节不再赘述。
图15示出了根据本公开的某些实施例的在IAB宿主处的装置1500的示意性结构框图。
如图15所示，装置1500包括请求接收模块1505、第一指示发送模块1510和第二指示发送模块1515。请求接收模块1505被配置为通过第一IAB宿主从第一IAB节点接收切换到第二IAB宿主的请求，其中到第二IAB宿主的切换是由第一IAB节点基于切换到第二IAB宿主的条件已经满足而触发的。第一指示发送模块1510被配置为通过第一IAB宿主按照自下而上的顺序向第一IAB节点下游的通信设备发送切换到第二IAB宿主的指示。第二指示发送模块1515被配置为在第一IAB节点的下一跳通信设备已经切换到第二IAB宿主之后，通过第一IAB宿主向第一IAB节点发送第一IAB节点的下一跳通信设备已经切换到第二IAB宿主的指示。
在某些实施例中，第一指示发送模块1510包括第一切换指示发送模块和第二切换指示发送模块。第一切换指示发送模块被配置为通过第一IAB宿主向第一IAB节点下游的末端通信设备发送切换到第二IAB宿主的指示。第二切换指示发送模块被配置为在末端通信设备已经切换到第二IAB宿主之后，通过第一IAB宿主向位于第一IAB节点下游的末端通信设备的上一跳通信设备发送切换到第二IAB宿主的指示。
在某些实施例中，在切换到第二IAB宿主的指示中包括第一IAB节点下游的通信设备从第一IAB宿主接收的预配置信息的索引信息，索引信息与由第二IAB宿主控制的目标小区相关联。第一指示发送模块1510包括配置生效模块，配置生效模块被配置为通过第一IAB节点下游的通信设备使预配置信息生效以切换到目标小区。
应理解，上文结合图5至图12描述的在源IAB宿主处的操作和特征同样适用于装置1500，并且具有同样的效果，具体细节不再赘述。
装置1300、1400和1500中所包括的模块可以利用各种方式来实现，包括软件、硬件、固件或其任意组合。在一些实施例中，一个或多个模块可以使用软件和/或固件来实现，例如存储在存储介质上的机器可执行指令。除了机器可执行指令之外或者作为替代，装置1300、1400和1500中的部分或者全部模块可以至少部分地由一个或多个硬件逻辑组件来实现。作为示例而非限制，可以使用的示范类型的硬件逻辑组件包括现场可编程门阵列(FPGA)、专用集成电路(ASIC)、专用标准品(ASSP)、片上系统(SOC)、复杂可编程逻辑器件(CPLD)，等等。
图16示出了其中可以实施本公开的某些实施例的设备1600的框图。设备1600能够用来实现例图5中所示的IAB节点520、530、540、UE 510或者IAB宿主550或560。
如图16所示，设备1600包括处理器1610，处理器1610控制设备1600的操作和功能。例如，在某些示例实施例中，处理器1610可以借助于与其耦合的存储器1620中所存储的指令1630来执行各种操作。存储器1620可以是适用于本地技术环境的任何合适的类型，并且可以利用任何合适的数据存储技术来实现，包括但不限于基于半导体的存储器件、磁存储器件和系统、光存储器件和系统。尽管图16中仅仅示出了一个存储器单元，但是在设备1600中可以有多个物理不同的存储器单元。
处理器1610可以是适用于本地技术环境的任何合适的类型，并且可以包括但不限于通用计算机、专用计算机、微控制器、数字信号控制器(DSP)以及基于控制器的多核控制器架构中的一个或多个。设备1600也可以包括多个处理器1610。处理器1610与通信单元1640 耦合。通信单元1640可以通过无线电信号或者借助于光纤、电缆和/或其他部件来实现信息的接收和发送。
当设备1600充当第一IAB节点时，处理器1610可以通过执行指令实现上文参考图5到图12描述的在第一IAB节点处的操作和动作。当设备1600充当第二IAB节点时，处理器1610可以通过执行指令实现上文参考图5到图12描述的在第二IAB节点处的操作和动作。当设备1600充当源IAB宿主时，处理器1610可以通过执行指令实现上文参考图5到图12描述的在源IAB宿主处的操作和动作。上文参考图5到图12所描述的所有特征均适用于设备1600，在此不再赘述。
一般而言，本公开的各种示例实施例可以在硬件或专用电路、软件、逻辑，或其任何组合中实施。某些方面可以在硬件中实施，而其他方面可以在可以由控制器、微处理器或其他计算设备执行的固件或软件中实施。当本公开的示例实施例的各方面被图示或描述为框图、流程图或使用某些其他图形表示时，将理解此处描述的方框、装置、系统、技术或方法可以作为非限制性的示例在硬件、软件、固件、专用电路或逻辑、通用硬件或控制器或其他计算设备，或其某些组合中实施。
作为示例，本公开的示例实施例可以在机器或计算机可执行指令的上下文中被描述，机器可执行指令诸如包括在目标的真实或者虚拟处理器上的器件中执行的程序模块中。一般而言，程序模块包括例程、程序、库、对象、类、组件、数据结构等，其执行特定的任务或者实现特定的抽象数据结构。在各示例实施例中，程序模块的功能可以在所描述的程序模块之间合并或者分割。用于程序模块的机器可执行指令可以在本地或者分布式设备内执行。在分布式设备中，程序模块可以位于本地和远程存储介质二者中。
用于实现本公开的方法的计算机程序代码可以用一种或多种编程语言编写。这些计算机程序代码可以提供给通用计算机、专用计算机或其他可编程的数据处理装置的处理器，使得程序代码在被计算机或其他可编程的数据处理装置执行的时候，引起在流程图和/或框图中规定的功能/操作被实施。程序代码可以完全在计算机上、部分在计算机上、作为独立的软件包、部分在计算机上且部分在远程计算机上或完全在远程计算机或服务器上执行。
在本公开的上下文中，机器可读介质或计算机可读介质可以是包含或存储用于或有关于指令执行系统、装置或设备的程序的任何有形介质。机器可读介质可以是机器可读信号介质或机器可读存储介质。机器可读介质可以包括但不限于电子的、磁的、光学的、电磁的、红外的或半导体系统、装置或设备，或其任意合适的组合。机器可读存储介质的更详细示例包括带有一根或多根导线的电气连接、便携式计算机磁盘、硬盘、随机存储存取器(RAM)、只读存储器(ROM)、可擦除可编程只读存储器(EPROM或闪存)、光存储设备、磁存储设备，或其任意合适的组合。
另外，尽管操作以特定顺序被描绘，但这并不应该理解为要求此类操作以示出的特定顺序或以相继顺序完成，或者执行所有图示的操作以获取期望结果。在某些情况下，多任务或并行处理会是有益的。同样地，尽管上述讨论包含了某些特定的实施细节，但这并不应解释为限制任何发明或权利要求的范围，而应解释为对可以针对特定发明的特定示例实施例的描述。本说明书中在分开的示例实施例的上下文中描述的某些特征也可以整合实施在单个示例实施例中。反之，在单个示例实施例的上下文中描述的各种特征也可以分离地在多个示例实施例或在任意合适的子组合中实施。
尽管已经以特定于结构特征和/或方法动作的语言描述了主题，但是应当理解，所附权利要求中限定的主题并不限于上文描述的特定特征或动作。相反，上文描述的特定特征和动作是作为实现权利要求的示例形式而被公开的。

Claims (19)

  1. 一种在回传接入一体化(IAB)网络中的切换方法，包括：
    第一IAB节点确定从第一IAB宿主切换到第二IAB宿主的条件已经满足；以及
    所述第一IAB节点向下一跳通信设备发送切换到所述第二IAB宿主的指示以指示所述下一跳通信设备切换到所述第二IAB宿主，或者向所述第一IAB宿主发送对于切换到所述第二IAB宿主的请求。
  2. 根据权利要求1所述的方法，其中在所述第一IAB节点向所述下一跳通信设备发送切换到所述第二IAB宿主的所述指示的情况下，所述方法还包括：
    响应于所述第一IAB节点从所述下一跳通信设备接收到切换完成的指示，所述第一IAB节点执行到所述第二IAB宿主的所述切换。
  3. 根据权利要求1所述的方法，其中在切换到所述第二IAB宿主的所述指示中包括由所述第二IAB宿主控制的目标小区的预配置信息的索引信息，以使得所述下一跳通信设备使所述预配置信息生效以切换到所述目标小区。
  4. 根据权利要求1所述的方法，其中切换到所述第二IAB宿主的所述指示由所述第一IAB节点通过回传适配协议BAP层控制分组数据单元PDU或媒体接入控制MAC控制元素CE发送给所述下一跳通信设备。
  5. 根据权利要求1所述的方法，其中在所述第一IAB节点向所述第一IAB宿主发送切换到所述第二IAB宿主的所述请求的情况下，所述方法还包括：
    所述第一IAB节点从所述第一IAB宿主接收所述第一IAB节点的所述下一跳通信设备已经切换到所述第二IAB宿主的指示；以及
    所述第一IAB节点执行到所述第二IAB宿主的切换。
  6. 一种在回传接入一体化(IAB)网络中的切换方法，包括：
    第二IAB节点从上一跳IAB节点接收从所述第一IAB宿主切换到第二IAB宿主的指示；以及
    所述第二IAB节点向下游通信设备转发从所述第一IAB宿主切换到所述第二IAB宿主的所述指示，以指示所述下游通信设备从所述第一IAB宿主切换到所述第二IAB宿主。
  7. 根据权利要求6所述的方法，还包括：
    响应于所述第二IAB节点从所述下一跳通信设备接收到切换完成的指示，所述第二IAB节点执行到所述第二IAB宿主的所述切换。
  8. 根据权利要求7所述的方法，其中
    在从所述第一IAB宿主切换到所述第二IAB宿主的所述指示中包括所述第二IAB节点从所述第一IAB宿主接收的预配置信息的索引信息，所述索引信息与由所述第二IAB宿主控制的目标小区相关联，并且
    所述第二IAB节点执行到所述第二IAB宿主的所述切换包括：所述第二IAB节点使所述预配置信息生效以切换到所述目标小区。
  9. 一种在回传接入一体化(IAB)网络中的切换设备，包括：
    条件确定模块，被配置为通过第一IAB节点确定从第一IAB宿主切换到第二IAB宿主的条件已经满足；以及
    第一发送模块，被配置为通过所述第一IAB节点向下一跳通信设备发送切换到所述第二 IAB宿主的指示以指示所述下一跳通信设备切换到所述第二IAB宿主，或者向所述第一IAB宿主发送对于切换到所述第二IAB宿主的请求。
  10. 根据权利要求9所述的设备，其中在所述第一发送模块被配置为通过所述第一IAB节点向所述下一跳通信设备发送切换到所述第二IAB宿主的所述指示的情况下，所述设备还包括：
    第一切换模块，被配置为响应于所述第一IAB节点从所述下一跳通信设备接收到切换完成的指示，通过所述第一IAB节点执行到所述第二IAB宿主的所述切换。
  11. 根据权利要求9所述的设备，其中在切换到所述第二IAB宿主的所述指示中包括由所述第二IAB宿主控制的目标小区的预配置信息的索引信息，以使得所述下一跳通信设备使所述预配置信息生效以切换到所述目标小区。
  12. 根据权利要求9所述的设备，其中切换到所述第二IAB宿主的所述指示由所述第一IAB节点通过回传适配协议BAP层控制分组数据单元PDU或媒体接入控制MAC控制元素CE发送给所述下一跳通信设备。
  13. 根据权利要求9所述的设备，其中在所述第一发送模块被配置为通过所述第一IAB节点向所述第一IAB宿主发送切换到所述第二IAB宿主的所述请求的情况下，所述设备还包括：
    指示接收模块，被配置为通过所述第一IAB节点从所述第一IAB宿主接收所述第一IAB节点的所述下一跳通信设备已经切换到所述第二IAB宿主的指示；以及
    第二切换模块，被配置为通过所述第一IAB节点执行到所述第二IAB宿主的切换。
  14. 一种在回传接入一体化(IAB)网络中的切换装置，包括：
    第一接收模块，被配置为通过第二IAB节点从上一跳IAB节点接收从所述第一IAB宿主切换到第二IAB宿主的指示；以及
    转发模块，被配置为通过所述第二IAB节点向下游通信设备转发从所述第一IAB宿主切换到所述第二IAB宿主的所述指示，以指示所述下游通信设备从所述第一IAB宿主切换到所述第二IAB宿主。
  15. 根据权利要求14所述的装置，还包括：
    第一切换模块，被配置为响应于所述第二IAB节点从所述下一跳通信设备接收到切换完成的指示，通过所述第二IAB节点执行到所述第二IAB宿主的所述切换。
  16. 根据权利要求15所述的装置，其中
    在从所述第一IAB宿主切换到所述第二IAB宿主的所述指示中包括所述第二IAB节点从所述第一IAB宿主接收的预配置信息的索引信息，所述索引信息与由所述第二IAB宿主控制的目标小区相关联，并且
    所述第一切换模块包括配置生效模块，所述配置生效模块被配置为通过所述第二IAB节点使所述预配置信息生效以切换到所述目标小区。
  17. 一种回传接入一体化(IAB)系统，包括：
    第一IAB节点，被配置为执行根据权利要求1到5中任一项所述的方法；以及
    第二IAB节点，被配置为执行根据权利要求6到8中任一项所述的方法。
  18. 一种通信设备，包括：
    处理器；处理器与存储器耦合，存储器存储指令，其中指令在被处理器执行时使根据权 利要求1到5中任一项或者权利要求6到8中任一项所述的方法被执行。
  19. 一种计算机可读存储介质，其上存储有程序，至少部分程序在由设备中的处理器执行时，使设备执行根据1到5中任一项或者权利要求6到8中任一项所述的方法。
PCT/CN2022/081715 2021-05-06 2022-03-18 接入回传一体化网络中的切换的方法、设备和介质 WO2022233190A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202110491612.5 2021-05-06
CN202110491612.5A CN115314951A (zh) 2021-05-06 2021-05-06 接入回传一体化网络中的切换的方法、设备和介质

Publications (1)

Publication Number Publication Date
WO2022233190A1 true WO2022233190A1 (zh) 2022-11-10

Family

ID=83853337

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/081715 WO2022233190A1 (zh) 2021-05-06 2022-03-18 接入回传一体化网络中的切换的方法、设备和介质

Country Status (2)

Country Link
CN (1) CN115314951A (zh)
WO (1) WO2022233190A1 (zh)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110536351A (zh) * 2019-02-15 2019-12-03 中兴通讯股份有限公司 Iab网络中信息处理方法、iab及计算机存储介质
WO2020006734A1 (en) * 2018-07-05 2020-01-09 Lenovo (Beijing) Limited Method and apparatus for backhaul link switching
CN111586744A (zh) * 2019-02-15 2020-08-25 华为技术有限公司 一种iab节点的切换方法及装置
WO2020191768A1 (en) * 2019-03-28 2020-10-01 Zte Corporation System and method for iab handovers

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020006734A1 (en) * 2018-07-05 2020-01-09 Lenovo (Beijing) Limited Method and apparatus for backhaul link switching
CN110536351A (zh) * 2019-02-15 2019-12-03 中兴通讯股份有限公司 Iab网络中信息处理方法、iab及计算机存储介质
CN111586744A (zh) * 2019-02-15 2020-08-25 华为技术有限公司 一种iab节点的切换方法及装置
WO2020191768A1 (en) * 2019-03-28 2020-10-01 Zte Corporation System and method for iab handovers

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
KDDI CORPORATION: "Considerations on top-down sequence during Inter-donor IAB node migration", 3GPP DRAFT; R3-210429, vol. RAN WG3, 14 January 2021 (2021-01-14), pages 1 - 6, XP051973031 *
SAMSUNG: "Discussion on inter-donor IAB node migration procedure for Rel-17 IAB", 3GPP DRAFT; R3-210216, vol. RAN WG3, 15 January 2021 (2021-01-15), pages 1 - 11, XP051974949 *

Also Published As

Publication number Publication date
CN115314951A (zh) 2022-11-08

Similar Documents

Publication Publication Date Title
RU2713442C1 (ru) Система и способ переключения сот
CN113556794B (zh) 通信方法、装置及系统
WO2015184889A1 (zh) 一种用户设备切换基站的方法及基站、用户设备
US10595239B2 (en) Data transmission method and device
JP7090737B2 (ja) 第１のアクセスネットワークノードを管理する方法、装置、５Ｇネットワークの一般ノードＢ（ｇＮＢ）、非一時的コンピュータ可読媒体、コンピュータプログラム製品、及びデータセット
WO2021147107A1 (zh) 一种通信方法及装置
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
WO2023011245A1 (zh) 通信方法和通信装置
WO2011100894A1 (zh) 切换方法和中继节点
WO2022022484A1 (zh) 一种逻辑信道lch的配置的方法、通信装置和通信系统
CN113873587A (zh) 一种用于iab网络通信的方法及相关设备
WO2022233190A1 (zh) 接入回传一体化网络中的切换的方法、设备和介质
WO2023130989A1 (zh) 一种通信方法及装置
CN114902726B (zh) 一种数据处理方法、通信装置和通信系统
TW202033047A (zh) 行動性中斷減少之方法及其使用者設備
WO2023226663A1 (zh) 通信方法和通信装置
WO2023011621A1 (zh) 一种通信方法及通信装置
WO2024067112A1 (zh) 一种通信方法、通信设备、介质及程序产品
WO2024093833A1 (zh) 一种通信方法和通信装置
WO2023131091A1 (zh) 通信方法和装置
WO2024067015A1 (zh) 通信方法、通信装置及通信系统
WO2022041085A1 (zh) 回传配置信息的更新或者释放方法及相关产品
CN113573373A (zh) 备用业务处理
WO2024094687A2 (en) Migration of nodes in an iab communication system
TW202420788A (zh) Ｉａｂ通訊系統中節點的遷移

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: 22798532

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 22798532

Country of ref document: EP

Kind code of ref document: A1